Digital Camera Patent AbstractTo present a digital camera capable of operating a piezoelectric
element without particularly preparing any boosting circuit inside
the digital camera. In a digital camera for acquiring image data
by taking a subject image, an imaging device for taking the subject
image, and a piezoelectric element for displacing the imaging device
are provided, and a main capacitor for stroboscope emission is used
as the power supply source for the piezoelectric element.
Digital Camera Patent ClaimsWhat is claimed is:
1. A digital camera for acquiring image data by acquiring a subject
image, comprising: an imaging device configured to acquire said
subject image; a piezoelectric element configured to displace said
imaging device; a detecting circuit configured to detect a representative
voltage indicative of a level of voltage presently being applied
to the piezoelectric element; a comparing unit configured to compare
a reference voltage corresponding to a predetermined amount of displacement
of the imaging device with the representative voltage detected by
the detecting circuit and to provide an output indicating that the
representative voltage detected by the detecting circuit is less
than the reference voltage; a charging unit including at least one
energy accumulating unit configured to power a strobe unit; and
a control element configured to supply electricity from the energy
accumulating unit of the charging unit to the piezoelectric element
to raise said level of voltage presently being applied to the piezoelectric
element responsive to the comparing unit providing the output indicating
that the representative voltage being detected by the detecting
circuit is less than the reference voltage.
2. The digital camera according to claim 1, wherein said energy
accumulating unit includes a main capacitor.
3. A digital camera capable of acquiring an image by shifting pixels,
comprising: an imaging device configured to capture a subject image;
a piezoelectric element configured to displace said imaging device;
a detecting circuit configured to detect a representative voltage
indicative of a level of voltage presently being applied to the
piezoelectric element; a switching unit configured to enable a charging
unit configured to charge said piezoelectric element by the energy
accumulated in at least one main capacitor configured to supply
energy to a strobe unit to provide strobe unit emission or to enable
discharge of said piezoelectric element; a comparing unit in the
charging unit configured to compare a reference voltage corresponding
to a predetermined amount of displacement of the imaging device
with the representative voltage detected by the detecting circuit
and to provide a charge indicating output indicating that the representative
voltage being detected by the detecting circuit is less than the
reference voltage; and a control unit configured to control said
switching unit to enable the charging unit including the comparing
unit to enable the charging of said piezoelectric element by the
energy accumulated in the at least one main capacitor in response
to the charging indicating output of said comparing unit in a first
image mode including a state of displacing said imaging device by
the piezoelectric element or to control said switching unit to enable
the discharge of said piezoelectric element in a second image mode
including no displacement of said imaging device by the piezoelectric
element.
4. A digital camera capable of acquiring an image by shifting pixels,
comprising: an imaging device configured to acquire a subject image;
a piezoelectric element configured to displace said imaging device;
a detecting circuit configured to detect a representative voltage
indicative of a level of voltage presently being applied to the
piezoelectric element; a switching unit configured to enable a charging
unit including a charge adjusting circuit to perform a charging
operation to charge said piezoelectric element to a specified value
of charge voltage by the energy accumulated in at least one main
capacitor configured to supply energy to a strobe unit to provide
strobe unit emission or to enable a discharging operation with discharge
of any charge voltage on said piezoelectric element; and a control
unit configured to control said switching unit to switch the charging
unit including the charge adjusting circuit into a first state to
provide the charging operation of said piezoelectric element with
image device displacement in a first imaging mode or to switch the
charging unit including the charge adjusting circuit into a second
state to provide the discharging operation to insure no displacement
of said piezoelectric element in a second imaging mode, wherein
said charge adjusting circuit includes a comparator portion configured
to compare a reference voltage corresponding to a predetermined
amount of displacement of the imaging device with the representative
voltage detected by the detecting circuit and to provide a first
output indicating that the representative voltage being detected
by the detecting circuit is less than the reference voltage or a
second output indicating that the representative voltage being detected
by the detecting circuit is equal to or greater than the reference
voltage and the charging unit including the charge adjusting circuit
provides the charging operation in response to the first output,
stops the-charging operation in response to the second output, and
restarts the charging operation when the first output is again provided,
and said control unit is configured to control acquiring a first
image during said first imaging mode, and capturing a second image
during said second imaging mode of said imaging device.
5. A digital camera capable of acquiring an image by shifting pixels,
comprising: an imaging device configured to capture a subject image;
a piezoelectric element configured to displace said imaging device;
a switching unit configured to charge said piezoelectric element
by the energy accumulated in at least one main capacitor configured
to supply energy to a strobe unit to provide strobe unit emission
or to discharge said piezoelectric element; and a control unit configured
to control said switching unit to provide a charging operation of
said piezoelectric element with image device displacement in a first
imaging mode or to provide a discharging operation to insure no
displacement of said piezoelectric element in a second imaging mode,
wherein said switching unit includes a charging switch circuit configured
to turn on or off charging of said piezoelectric element by the
energy accumulated in at least one main capacitor during said charging
operation, a discharging switch circuit configured to turn on or
off discharging of said piezoelectric element, a detecting circuit
configured to detect a representative voltage indicating a level
of voltage presently being applied to said piezoelectric element,
and a comparing circuit configured to make a comparison of the representative
voltage detected by said detecting circuit and a reference voltage,
said charging switch circuit configured to turn on the charging
operation of said piezoelectric element when the comparison indicates
that the representative voltage detected by the detecting circuit
is less than the reference voltage, and said control unit is configured
to control acquiring a first image during said first imaging mode,
and capturing a second image during said second imaging mode of
said imaging device.
6. A digital camera capable of taking an image by shifting pixels,
comprising: an imaging device configured to capture a subject image;
a piezoelectric element configured to displace said imaging device;
a switching unit configured to charge said piezoelectric element
by energy accumulated in at least one main capacitor configured
to supply energy to a strobe unit to provide strobe unit emission
or to discharge said piezoelectric element; a detecting circuit
configured to detect a representative voltage indicating a level
of voltage presently being applied to the piezoelectric element;
and a control unit configured to control said switching unit to
provide a charging operation of said piezoelectric element with
image device displacement in a first imaging mode or to provide
a discharging operation to insure no displacement of said piezoelectric
element in a second imaging mode, wherein said switching unit includes
a comparator portion configured to compare a reference voltage corresponding
to a predetermined amount of displacement of the imaging device
with the representative voltage detected by the detecting circuit
and to provide a charging output indicating that the representative
voltage detected by the detecting circuit is less than the reference
voltage and the switching unit responding to the charging output
to charge said piezoelectric element by the energy accumulated in
the at least one main capacitor during the charging operation.
7. A digital camera capable of acquiring an image by shifting pixels,
comprising: an imaging device configured to capture a subject image;
a piezoelectric element configured to displace said imaging device;
a switching unit configured to charge said piezoelectric element
by the energy accumulated in at least one main capacitor configured
to supply energy to a strobe unit to provide strobe unit emission
or to discharge said piezoelectric element; a control unit configured
to control said switching unit to provide a charging operation of
said piezoelectric element with image device displacement in a first
imaging mode or to provide a discharging operation to insure no
displacement of said piezoelectric element in a second imaging mode
a charging switch circuit configured to turn on or off charging
of said piezoelectric element by the energy accumulated in the at
least one main capacitor during said charging operation; a discharging
switch circuit configured to turn on or off discharging of said
piezoelectric element during said discharging operation; a detecting
circuit configured to detect a representative voltage indicative
of a voltage level presently being applied to said piezoelectric
element; a comparing unit configured to make a comparison of the
representative voltage detected by said detecting circuit and a
reference voltage indicating a displacement of the imaging device,
wherein said charging switch circuit is configured to turn on charging
of said piezoelectric element when the comparison indicates that
the representative voltage detected by said detecting circuit is
less than the reference voltage during the charging operation.
8. A digital camera capable of acquiring an image by shifting pixels,
comprising: an imaging device configured to capture a subject image;
a means for displacing said imaging device responsive to a charging
voltage; a means for applying the charging voltage to said means
for displacing from energy accumulated in at least one means for
storing energy, said means for storing energy also supplying stored
energy to a strobe unit for providing strobe unit emission; a means
for discharging the charging voltage from said means for displacing;
a detecting means for detecting a representative voltage indicating
a level of voltage presently being applied to the means for displacing;
a means for controlling said means for applying the charging voltage
to said means for displacing to provide the charging voltage to
said means for displacing for providing image device displacement
in a first imaging mode or for controlling said means for discharging
to discharge the charging voltage from said means for displacing
to insure no displacement of said means for displacing in a second
imaging mode; and a means for comparing a reference voltage corresponding
to a predetermined amount of displacement of the imaging device
with the representative voltage detected by the detecting means
and for providing a first mode output indicating that the respective
voltage is less than the reference voltage and the means for applying
charging voltage to said means for displacing responding to the
first mode output to apply the charging voltage to said means for
displacing by applying the energy accumulated in the at least one
means for storing energy to said means for displacing.
9. A digital camera capable of acquiring an image by shifting pixels,
comprising: an imaging device configured to acquire a subject image;
a piezoelectric element configured to displace said imaging device;
a detecting circuit configured to detect a representative voltage
indicative of a level presently being applied to the piezoelectric
element; a switching unit configured to charge said piezoelectric
element by the energy accumulated in at least one main capacitor
also configured to supply energy to a strobe unit to provide strobe
unit emission, and a control unit configured to control said switching
unit to provide a charging operation to provide image displacement
in an imaging mode of said piezoelectric element, wherein said switching
unit includes a charge adjusting circuit including a comparator
portion configured to compare the representative voltage on said
piezoelectric element detected by the detecting circuit to a reference
voltage value indicating a predetermined amount of displacement
of the imaging device and when the representative voltage detected
by the detecting circuit becomes lower than the reference voltage
value, said adjusting circuit is configured to trigger the switching
unit to charge said piezoelectric element in a state of displacing
said imaging device.
10. A digital camera capable of acquiring an image by shifting
pixels, comprising: an imaging device configured to acquire a subject
image; a piezoelectric element configured to displace said imaging
device; a switching unit configured to charge said piezoelectric
element by the energy accumulated in at least one main capacitor
configured to supply energy to a strobe unit configured to also
provide strobe unit emission, the switching unit also being configured
to discharge said piezoelectric element; a control unit configured
to control said switching unit to provide a charging operation and
to provide a discharging operation of said piezoelectric element,
wherein said switching unit includes a charging switch circuit configured
to turn on or off charging of said piezoelectric element, a discharging
switch circuit configured to turn on or off discharging of said
piezoelectric element, a detecting circuit configured to detect
representative voltage indicative of a level of voltage presently
being applied to said piezoelectric element, and a comparing circuit
configured to compare the representative voltage detected by said
detecting circuit and a reference voltage indicating displacement
of the piezoelectric element, wherein said charging switch circuit
is configured to turn on charging of said piezoelectric element
based on the comparison by said comparing circuit indicating the
respective voltage detected by said detecting circuit is less than
the reference voltage, and said control unit is configured to control
acquiring a first image in a state not displacing said imaging device,
and acquiring a second image in a state of charging said piezoelectric
element so as to displace said imaging device.
11. A digital camera capable of acquiring an image by shifting
pixels, comprising: an imaging device configured to acquire a subject
image; a piezoelectric element configured to displace said imaging
device; a detecting circuit configured to detect a representative
voltage indicating a level of voltage presently being applied to
the piezoelectric element; a switching unit configured to charge
said piezoelectric element by the energy accumulated in at least
one main capacitor configured to supply energy to a strobe unit
to provide strobe unit emission; and a control unit configured to
control said switching unit for controlling a charging and discharging
operation of said piezoelectric element, wherein said switching
unit includes a comparing unit configured to compare the respective
voltage detected by said detecting circuit to a reference voltage
indicating displacement of the imaging device, the comparing unit
being configured to provide an output during the changing operation
to control the switching unit to charge said piezoelectric element
by the energy accumulate in the main capacitor.
12. A digital camera capable of taking an image by shifting pixels,
comprising: an imaging device configured to capture a subject image;
a piezoelectric element configured to displace said imaging device;
a switching unit configured to charge said piezoelectric element
by the energy accumulated in at least one main capacitor configured
to supply energy to a strobe unit to provide for strobe unit emission
or to discharge said piezoelectric element; and a control unit configured
to control said switching unit to provide a charging operation of
said piezoelectric element with image device displacement in a first
imaging mode or to provide a discharging operation to insure no
displacement of said piezoelectric element in a second imaging mode,
wherein said switching unit includes a charging switch circuit configured
to turn on charging of said piezoelectric element by the energy
accumulated in the at least one main capacitor during said charging
operation and a detecting circuit configured to detect a respective
voltage indicative of a level of voltage presently being provided
to said piezoelectric element, the switching unit further including
a comparing unit configured to make a comparison of the respective
voltage detected by said detecting circuit and a reference voltage,
said charging switch circuit configured to turn on charging of said
piezoelectric element when the comparison indicates that the respective
voltage detected by said detecting circuit is less than the reference
voltage during the charging operation. Digital Camera Patent DescriptionFIELD OF THE INVENTION
The present invention relates to a digital camera, and more particularly
to a digital camera having an imaging device displaced by a piezoelectric
element.
BACKGROUND OF THE INVENTION
A higher image quality is demanded in the digital camera. To obtain
an image of high quality, many pixels of a solid state imaging device
are set, and a longer reading time is required. Accordingly, a pixel
shifting technique is proposed recently in order to obtain a higher
picture quality by a smaller number of pixels.
Various techniques about power source circuit for an optical camera
are disclosed. For example, a power source circuit for camera is
disclosed in Japanese Laid-open Patent No. 5-165080, and in this
power source circuit for camera incorporating an oscillating wave
motor and a flash device, a first voltage to be applied to a piezoelectric
element of the oscillating wave motor for operating the mechanism
in the camera, and a second voltage for operating the flash device
are changed over by an output voltage changeover circuit depending
on each operation by composing a boosting circuit by using a pair
of boosting transformers, a switching element, an oscillation control
circuit, and an output voltage changeover circuit, and it is designed
to drive an ultrasonic motor for film take-up, an ultrasonic motor
for lens driving, and a stroboscope circuit.
The power source circuit for camera disclosed in Japanese Laid-open
Patent No. 7-301843 comprises a stroboscope emission device for
stroboscope emission, a capacitor for accumulating emission energy
for emitting this stroboscope emission device, charging means for
boosting the supply voltage of the battery, and charging the capacitor
by the boosted voltage, an actuator provided in the camera, a drive
circuit for driving the actuator, changeover means for supplying
either the emission energy accumulated in the capacitor or the energy
from the power source battery selectively to the actuator or the
drive circuit, supply voltage detecting means for detecting the
supply voltage, temperature measuring means for detecting the environmental
temperature of the camera, and control means for controlling the
changeover means by selecting either the capacitor or the supply
voltage on the basis of the supply voltage detected by the supply
voltage detecting means and the environmental temperature detected
by the temperature measuring means, in which the capacitor for accumulating
the stroboscope emission energy is used as the power source, and
the driving source for the lens driving mechanism of camera and
film feed mechanism is obtained.
However, in the power source circuit for camera disclosed in Japanese
Laid-open Patent No. 5-165080, a large circuit scale is required
because the output changeover function is needed in the boosting
circuit. In the power source circuit for camera disclosed in Japanese
Laid-open Patent No. 7-301843, only the technique of driving the
lens driving mechanism of camera and the film feed mechanism is
disclosed by using the capacitor for accumulating the stroboscope
emission energy as the power source, and nothing is proposed about
the power source technology of the piezoelectric element for displacing
the imaging device.
SUMMARY OF THE INVENTION
It is an object thereof to present a digital camera capable of
operating the piezoelectric element for displacing the imaging device,
without requiring any particular boosting circuit in the digital
camera and provides a digital camera capable of obtaining an image
of high definition.
To achieve the object, according to one aspect of this invention,
a digital camera for acquiring image data by taking a subject image
comprises imaging device for taking a subject image, and a piezoelectric
element for displacing the imaging device, in which energy accumulating
means for supplying an electric power to other unit is used as an
electric power supply source for the piezoelectric element.
According to another aspect of this invention, in the digital camera
according to one aspect of this invention, in which the energy accumulating
means is composed of a main capacitor for strobe unit emission provided
inside or outside, and the piezoelectric element is charged by the
energy accumulated in this main capacitor.
According to still another aspect of this invention, a digital
camera capable of taking an image by shifting pixels comprises imaging
device for taking a subject image, a piezoelectric element for displacing
the imaging device, switching means for charging the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharging the piezoelectric
element, and control means for controlling the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, in which the control means controls to take a first image
by charging the piezoelectric element in a state of displacing the
imaging device, and take a second image by discharging the piezoelectric
element in a state before displacement of the imaging device.
According to still another aspect of this invention, a digital
camera capable of taking an image by shifting pixels comprises imaging
device for taking a subject image, a piezoelectric element for displacing
the imaging device, switching means for charging the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharging the piezoelectric
element, and control means for controlling the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, in which the switching means includes a charge adjusting
circuit for stopping the charging operation when the charged voltage
in the piezoelectric element becomes a specified value to hold this
charged voltage, and restarting charging operation when the charged
voltage in the piezoelectric element becomes lower than a specified
value, and the control means controls to take a first image by charging
the piezoelectric element in a state of displacing the imaging device,
and take a second image by discharging the piezoelectric element
in a state before displacement of the imaging device.
According to still another aspect of this invention, a digital
camera capable of taking an image by shifting pixels comprises imaging
device for taking a subject image, a piezoelectric element for displacing
the imaging device, switching means for charging the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharging the piezoelectric
element, and control means for controlling the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, in which the switching means includes a charging switch
circuit for turning on or off charging of the piezoelectric element,
a discharging switch circuit for turning on or off discharging of
the piezoelectric element, a detecting circuit for detecting the
charged voltage in the piezoelectric element, and comparing means
for comparing the charged voltage in the piezoelectric element detected
by the detecting means and a reference voltage, the charging switch
circuit turns on or off charging of the piezoelectric element on
the basis of the result of comparison by the comparing means, and
the control means controls to take a first image by charging the
piezoelectric element in a state of displacing the imaging device,
and take a second image by discharging the piezoelectric element
in a state before displacement of the imaging device.
According to still another aspect of this invention, a digital
camera capable of taking an image by shifting pixels comprises imaging
device for taking a subject image, a piezoelectric element for displacing
the imaging device, switching means for charging the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharging the piezoelectric
element, and control means for controlling the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, in which the control means controls so as to stop the charging
operation when the piezoelectric element reaches a specified voltage,
and to take a first image by charging the piezoelectric element
in a state of displacing the imaging device, and take a second image
by discharging-the piezoelectric element in a state before displacement
of the imaging device.
According to still another aspect of this invention, a digital
camera capable of taking an image by shifting pixels comprises imaging
device for taking a subject image, a piezoelectric element for displacing
the imaging device, switching means for charging the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharging the piezoelectric
element, and control means for controlling the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, and also controlling to stop the charging operation when
the piezoelectric element reaches a specified voltage, in which
the switching means includes a charging switch circuit for turning
on or off charging of the piezoelectric element, a discharging switch
circuit for turning on or off discharging of the piezoelectric element,
and a detecting circuit for detecting the charged voltage in the
piezoelectric element, and the control means controls to turn on
or off the charging switch circuit on the basis of the detected
voltage of the detecting circuit, and to take a first image by charging
the piezoelectric element in a state of displacing the imaging device,
and take a second image by discharging the piezoelectric element
in a state before displacement of the imaging device.
According to still another aspect of this invention, a digital
camera capable of taking an image by shifting pixels comprises imaging
device for taking a subject image, a piezoelectric element for displacing
the imaging device, switching means for charging the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharging the piezoelectric
element, and control means for controlling the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, in which the control means controls to take a first image
in a state not displacing the imaging device, and take a second
image by charging the piezoelectric element in a state of displacing
the imaging device.
According to still another aspect of this invention, a digital
camera capable of taking an image by shifting pixels comprises imaging
device for taking a subject image, a piezoelectric element for displacing
the imaging device, switching means for charging the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharging the piezoelectric
element, and control means for controlling the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, in which the switching means includes a charge adjusting
circuit for stopping the charging operation when the charged voltage
in the piezoelectric element becomes a specified value to hold this
charged voltage, and restarting charging operation when the charged
voltage in the piezoelectric element becomes lower than a specified
value, and the control means controls to take a first image in a
state not displacing the imaging device, and take a second image
by charging the piezoelectric element in a state of displacing the
imaging device.
According to still another aspect of this invention, a digital
camera capable of taking an image by shifting pixels comprises imaging
device for taking a subject image, a piezoelectric element for displacing
the imaging device, switching means for charging the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharging the piezoelectric
element, and control means for controlling the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, in which the switching means includes a charging switch
circuit for turning on or off charging of the piezoelectric element,
a discharging switch circuit for turning on or off discharging of
the piezoelectric element, a detecting circuit for detecting the
charged voltage in the piezoelectric element, and comparing means
for comparing the charged voltage in the piezoelectric element detected
by the detecting means and a reference voltage, the charging switch
circuit turns on or off charging of the piezoelectric element on
the basis of the result of comparison by the comparing means, and
the control means controls to take a first image in a state not
displacing the imaging device, and take a second image by charging
the piezoelectric element in a state of displacing the imaging device.
According to still another aspect of this invention, a digital
camera capable of taking an image by shifting pixels comprises imaging
device for taking a subject image, a piezoelectric element for displacing
the imaging device, switching means for charging the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharging the piezoelectric
element, and control means for controlling the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, in which the control means controls so as to stop the charging
operation when the piezoelectric element reaches a specified voltage,
and to take a first image in a state not displacing the imaging
device, and take a second image by charging the piezoelectric element
in a state of displacing the imaging device.
According to still another aspect of this invention, a digital
camera capable of taking an image by shifting pixels comprises imaging
device for taking a subject image, a piezoelectric element for displacing
the imaging device, switching means for charging the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharging the piezoelectric
element, and control means for controlling the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, and also controlling to stop the charging operation when
the piezoelectric element reaches a specified voltage, in which
the switching means includes a charging switch circuit for turning
on or off charging of the piezoelectric element, a discharging switch
circuit for turning on or off discharging of the piezoelectric element,
and a detecting circuit for detecting the charged voltage in the
piezoelectric element, and the control means controls to turn on
or off the charging switch circuit on the basis of the detected
voltage of the detecting circuit, and to take a first image in a
state not displacing the imaging device, and take a second image
by charging the piezoelectric element in a state of displacing the
imaging device.
Other objects and features of this invention will become understood
from the following description with reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a structure of a digital camera
using an imaging device according to the invention.
FIG. 2 is a schematic diagram showing a mounting structure of piezoelectric
element in imaging block in FIG. 1.
FIG. 3 is a flowchart explaining an image taking operation by shifting
pixels.
FIG. 4 is a timing chart explaining the driving and transfer of
imaging device, and the charging and discharging timing of piezoelectric
element.
FIG. 5 is a circuit diagram showing a structure of a piezoelectric
element charging circuit for automatically terminating the charging
operation into the piezoelectric element.
FIG. 6 is a diagram showing the charging and discharging sequence
of the piezoelectric element charging circuit in FIG. 5.
FIG. 7 is a circuit diagram showing the structure of piezoelectric
element charging circuit in the case of control of charging stop
to the piezoelectric element by a system controller.
FIG. 8 is a diagram showing the charging and discharging sequence
of the piezoelectric element charging circuit in FIG. 7.
FIG. 9 is a timing chart explaining the driving and transfer of
imaging device, and the charging and discharging timing of piezoelectric
element, in the case of taking a first image in discharged state
of the piezoelectric element and taking a second image in charged
state of the piezoelectric element.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the accompanying drawings, preferred embodiments
of the digital camera of the invention are described in detail below.
FIG. 1 is a block diagram of a digital camera of the invention.
The digital camera 1 shown in FIG. 1 mainly comprises an imaging
block 2 for taking a subject image to obtain analog image data,
a signal processing block 3 for processing the digital image data
digitized from the analog image data obtained in this imaging block
2, and issuing outside, and a stroboscope circuit 4.
In this digital camera 1, an A/D converter 5 for converting analog
image data into digital data is provided between the imaging block
2 and the signal processing block 3, and the signal processing block
3 includes a signal generator 7 for generating a signal depending
on the manipulation of mode switch or the like not shown, and issuing
the signal to the signal processing block 3.
The imaging block 2 includes an optical lens 20, and an imaging
unit 21 provided movably according to the control of the signal
processing block 3. The imaging unit 21 includes a shutter mechanism
(mechanical shutter or diaphragm) 22 for shielding the light entering
the lens 20 by optical mechanism, an imaging device 23 such as CCD
for receiving the light entering the lens 20 and converting into
an electrical signal (analog image data), and a piezoelectric element
24 for supporting this imaging device 23, moving the photo detecting
surface of the imaging device 23 parallel to the imaging surface,
and changing the imaging range of the same subject to shift the
pixels. The output of the imaging device 23 is supplied into the
A/D converter 5.
The signal processing block 3 comprises, for example, a system
controller 30, a sensor data output unit 31, a memory group 32 composed
of a plurality of memories, a pixel shifting unit 33, and others.
The system controller 30 is coupled to the units of the imaging
unit 21 of the imaging block 2, strobe unit circuit 4, A/D converter
5, sensor data output unit 31, memory group 32, pixel shifting processing
unit 33, piezoelectric element charging circuit 6, and signal generator
7, and controls the operation depending on the imaging operation,
stroboscope emission operation, A/D conversion, read/write of memory,
pixel shifting, and key input.
The system controller 30 is composed of microcomputer and others,
and executes control and operation of each unit by operating the
microcomputer according to the programs stored in the ROM.
The sensor data output unit 31 is coupled to the output of the
A/D converter 5, and receives the image data, and issues the input
digital image data to any one of the memories of the memory group
32 in a later stage according to the control of the system controller
30.
The memory group 32 has a plurality of memories, and depending
on the control of the system controller 30, one memory is used for
storing image data for one image taking, or the digital image data
is read out from one memory, and is supplied into the pixel shifting
processing unit 33 in a later stage.
The pixel shifting processing unit 33 shifts pixels on the basis
of the digital image data supplied from the memory group 32, and
more specifically, depending on the pixel deviation amount (for
example, pixel 1/2 pitch) when the imaging range is changed by the
piezoelectric element 24, the same subject is enhanced in picture
quality, and finally the image data for one image is obtained.
The output of the pixel shifting processing unit 33 is connected
to an external terminal not shown, and is connected to an external
device such as personal computer, and is sent out.
The strobe unit circuit 4 is a circuit for emitting a stroboscope
by the control of the system controller 30, and comprises a strobe
unit emission circuit 41 having reflector and discharge tube for
strobe unit emission, a main capacitor 42 for supplying energy to
the strobe unit emission circuit 41, a main capacitor charging circuit
43 for charging the main capacitor 42, and others.
The piezoelectric element charging circuit 6 charges the piezoelectric
element 24 of the imaging unit 21 by using the main capacitor 42
of the strobe unit circuit 4 as secondary power source, by the control
of the system controller 30.
The signal generator 7 includes a release key for imaging by actuating
an electronic shutter or shutter mechanism 22, and mode switches
for setting various modes.
The piezoelectric element 24 is explained. FIG. 2 is a schematic
block diagram showing a mounting structure of the piezoelectric
element 24 in the imaging block 2. The laminate type piezoelectric
element 24 has one end connected to a substrate 26A, and supports
a device holder 25 supporting the imaging device 23 at other end.
The device holder 25 moves in the arrow direction by the operation
of the piezoelectric element 24. While the piezoelectric element
24 is not charged, the imaging device 23 is at the position of P
in the diagram, and when the piezoelectric element 24 is charged,
the piezoelectric element is extended, and the imaging device 23
is displaced to the position of X. When the piezoelectric element
24 is discharged, it returns to the position of P. The displacement
extent (X P) of the piezoelectric element 24 may be, for example,
defined to be 1/2 pixel.
The piezoelectric element 24 changes the imaging range (shifting
operation of pixels of the piezoelectric element 24) in horizontal,
vertical or diagonal direction, depending on the mounting angle
in the imaging block 2.
Referring now to FIG. 3 and FIG. 4, the pixel shifting imaging
operation of the digital camera having such structure is explained.
FIG. 3 is a flowchart explaining an image taking operation by shifting
pixels of the digital camera, and FIG. 4 is a timing chart explaining
the driving and transfer of the imaging device 23, and the charging
and discharging timing of piezoelectric element 24. In the diagram,
(a) shows operating states of the digital camera, (b) shows vertical
synchronous signal (VD), (c) shows charge sweep pulse (SUB), (d)
shows operation of mechanical shutter, (e) shows charge transfer
(CCDOUT) of the imaging device 23, and (f) shows the voltage applied
to the piezoelectric element 24.
In FIG. 3, while monitoring as shown in FIG. 4(a), when the release
key of the signal generator 7 is pressed, as shown in FIG. 4(f),
the piezoelectric element charging circuit 6 starts charging of
the piezoelectric element 24 by using the main capacitor 42 as the
secondary power source depending on the control signal of the system
controller 30 (step S101). The piezoelectric element charging circuit
6, when charging the piezoelectric element 24 up to a prescribed
voltage, terminates charging of the piezoelectric element 24 (step
102) automatically (see FIG. 5) or depending on the control signal
from the system controller 30 (see FIG. 7). The constitution of
the piezoelectric element charging circuit 6 for terminating charging
of the piezoelectric element 24 automatically or depending on the
control signal from the system controller 30 is explained below.
By this charging, the piezoelectric element 24 is extended, and
the imaging device 23 is displaced by a specified extent (to the
position of X in FIG. 2).
Consequently, as shown in FIG. 4(d), the system controller 30 closes
the mechanical shutter, and takes a first image (step S103). After
taking the first image, as shown in FIG. 4(e), the electric charge
is transferred from the imaging device 23 in the sequence of odd
line (Odd signal) and even line (Even signal). After this transfer,
the image data is written into the memory for the first image in
the memory group 32 according to the control of the system controller
30. After completion of transfer of the electric charge from the
imaging device 23, as shown in FIG. 4(d), the system controller
30 opens the mechanical shutter.
Then, as shown in FIG. 4(f), the piezoelectric element charging
circuit 6 starts discharging of the piezoelectric element 24 (step
S104) depending on the control signal of the system controller 30.
By this discharge, the piezoelectric element 24 is expanded, and
the imaging device 23 returns to the original position (position
P in FIG. 2). When discharging of the piezoelectric element 24 is
over (step S105), as shown in FIG. 4(d), the system controller 30
opens the mechanical shutter and takes a second image (step S106).
After taking the second image, as shown in FIG. 4 (e), the electric
charge is transferred from the imaging device 23 in the sequence
of odd line (Odd signal) and even line (Even signal). The image
data obtained from the second image taking is transferred same as
in the case of the first image taking, and is written into a different
memory from the memory of the first image in the memory group 32
according to the control of the system controller 30.
The pixel shifting processing unit 33 enhances the picture quality
in the same subject depending on the pixel shift amount (for example,
pixel 1/2 pitch) when the imaging range is changed by the piezoelectric
element 24, on the basis of the digital image data taken by the
first image and the digital image data taken by the second image
supplied from the memory group 32, and finally the image data for
one picture is obtained.
FIG. 5 is a circuit diagram showing a structure of the piezoelectric
element charging circuit 6 for automatically terminating the charging
operation into the piezoelectric element 24. The piezoelectric element
charging circuit 6 comprises, as shown in the diagram, a charging
switch circuit 61 for turning on or off charging of the piezoelectric
element 24 on the basis of the output of a comparator 64, a discharging
switch circuit 62 for turning on or off discharging of the piezoelectric
element 24, a voltage dividing resistance 63 for detecting the voltage
of the piezoelectric element 24, the comparator 64 for comparing
the voltage of the piezoelectric element 24 and the reference voltage,
and a comparator power source switch circuit 65 for turning on or
off supply of power source to the comparator 64.
As mentioned above, the energy charged in the main capacitor 42
is used as the secondary power source of the piezoelectric element
24. First, the operation of charging the piezoelectric element 24
is explained. To charge the piezoelectric element 24, when a control
signal of H level is supplied from the system controller 30 to SW1
of the comparator power source switch circuit 65, the comparator
power source switch circuit 65 supplies power source to the comparator
64.
The comparator 64 compares the detected voltage VP obtained by
dividing the voltage of the piezoelectric element 24 by the voltage
dividing resistance 63, and the reference voltage (Vref), and when
the voltage VP of the piezoelectric element 24 is less than the
reference voltage (Vref), a signal of H level is issued to the charging
switch circuit 61. The charging switch circuit 61 is turned on when
a signal of H level is entered from the comparator 64, and charging
from the main capacitor 42 to the piezoelectric element 24 is started.
The reference voltage (Vref) may be either fixed voltage, or variable
voltage controlled by the system controller 30.
When charging into the piezoelectric element 24 is advanced until
the detected voltage VP of the voltage dividing resistance 63 becomes
equal to the reference voltage (Vref), the output level of the comparator
64 to the charging switch circuit 61 becomes L level, and the charging
switch circuit 61 is turned off, and charging into the piezoelectric
element 24 is terminated automatically.
The operation of discharging the piezoelectric element 24 is explained
below. When discharging the piezoelectric element 24, the system
controller 30 issues a control signal of L level to Sw1 of the comparator
power source switch circuit 65 to turn off the comparator power
source switch circuit 65, and supply of power source to the comparator
64 is cut off, and a control signal of H level is issued to SW2
of the discharging switch circuit 62 to turn on the discharging
switch circuit 62, thereby discharging the electric charge accumulated
in the piezoelectric element 24 to the ground.
In this case, supply of power source to the comparator 64 is controlled
by the control of SW1, but it is also possible to turn on the reference
voltage (Vref) by the control of SW1. The illustration of circuit
configuration in such case is omitted.
Referring next to FIG. 6, the charging and discharging sequence
of the piezoelectric element charging circuit 6 in FIG. 5 is explained.
FIG. 6 is a diagram showing the charging and discharging sequence
of the piezoelectric element charging circuit 6 in FIG. 5. In the
diagram, (a) shows the detected voltage VP obtained by dividing
the voltage of the piezoelectric element 24 by the voltage dividing
resistance 63, (b) shows a control signal entered from the system
controller 30 into SW1 of the comparator power source switch circuit
65, and (c) shows a control signal entered from the system controller
30 into SW2 of the charging switch circuit 61.
In FIG. 6, the initial state of the voltage value of the piezoelectric
element 24 is 0 V. The system controller 30 issues a control signal
of H level to SW1 at time t1, and starts charging of the piezoelectric
element 24. After start of charging, at time t2, converging at VP=Vref,
charging of the piezoelectric element 24 is stopped automatically.
In this state, a first image is taken. Later, the system controller
30 sets the control signal to SW1 to L level, and at time t3, a
control signal of H level is issued to SW2, and the piezoelectric
element 24 is discharged. After completion of discharging, when
becoming VP=0 V, a second image is taken.
FIG. 7 is a circuit diagram showing the structure of the piezoelectric
element charging circuit 6 in the case of control of charging stop
to the piezoelectric element 24 by the system controller 30. The
piezoelectric element charging circuit 6 comprises, as shown in
the diagram, a charging switch circuit 66 for turning on or off
charging into the piezoelectric element 24 from the main capacitor
42 by the control of the system controller 30, a discharging switch
circuit 67 for turning on or off discharging of the piezoelectric
element 24 by the control of the system controller 30, and a voltage
dividing resistance 68 for detecting the voltage of the piezoelectric
element 24.
As mentioned above, the energy charged in the main capacitor 42
is used as the secondary power source of the piezoelectric element
24. To charge the piezoelectric element 24, the system controller
30 issues a control signal of H level to SW3 of the charging switch
circuit 66, and the charging switch circuit 66 is turned on, and
charging from the main capacitor 42 into the piezoelectric element
24 is started.
On the other hand, a detected voltage VP' obtained by dividing
the voltage of the piezoelectric element 24 by the voltage dividing
resistance 68 is issued to the system controller 30. The system
controller 30 converts the entered detected voltage VP' into digital
data by a built-in A/D converter, and acquires as detected voltage
data, and judges if it is a specified voltage value or not. The
system controller 30, when the piezoelectric element 24 is charged
up to the specified voltage value, issues a control signal of L
level to SW3 of the charging switch circuit 66, and turns off the
charging switch circuit 66 to terminate the charging of the piezoelectric
element 24, thereby maintaining the high potential of the piezoelectric
element 24.
The operation of discharging the piezoelectric element 24 is explained.
When discharging the piezoelectric element 24, the system controller
30 issues a control signal of H level to SW4 of the discharging
switch circuit 67 to turn on the discharging switch circuit 67,
and the electric charge accumulated in the piezoelectric element
24 is discharged to the ground.
Referring to FIG. 8, the charging and discharging sequence of the
piezoelectric element charging circuit 6 in FIG. 7 is explained.
FIG. 8 is a diagram showing the charging and discharging sequence
of the piezoelectric element charging circuit 6 in FIG. 7. In the
diagram, (a) shows the detected voltage VP' obtained by dividing
the voltage of the piezoelectric element 24 by the voltage dividing
resistance 68, (b) shows a control signal entered from the system
controller 30 into SW3 of the charging switch circuit 66, and (c)
shows a control signal entered from the system controller 30 into
SW4 of the discharging switch circuit 67.
In FIG. 8, the initial state of the voltage value of the piezoelectric
element 24 is 0 V. In the case of VP'=Va, it is supposed that the
piezoelectric element 24 is charged to a specified voltage. The
system controller 30 issues a control signal of H level to SW3 at
time t1', and starts charging of the piezoelectric element 24. After
start of charging, at time t2', achieving VP'=Va, when the piezoelectric
element 24 is charged up to the specified voltage value, the system
controller 30 stops charging of the piezoelectric element 24 by
issuing a control signal of L level to SW3. In this state, a first
image is taken. Later, the system controller 30 issues a control
signal of H level to SW4 at time t3', and discharges the piezoelectric
element 24. After completion of discharging of the piezoelectric
element 24, when becoming VP 0 V, a second image is taken.
As explained herein, since the main capacitor 42 for strobe unit
emission is used as the electric power supply source for the piezoelectric
element 24, without particularly preparing the boosting circuit
in the digital camera, the piezoelectric element can be operated.
In the piezoelectric element charging circuit 6 shown in FIG. 5
and FIG. 7, at the time of taking images by shifting pixels, the
piezoelectric element 24 is charged by the energy accumulated in
the main capacitor 42 for strobe unit emission, or the piezoelectric
element 24 is discharged, and the system controller 30 controls
the piezoelectric element charging circuit 6, and controls the charging
and discharging sequence of the piezoelectric element 24, and therefore
the piezoelectric element can be operated without particularly preparing
the boosting circuit in the digital camera, and an image of high
definition is obtained.
In the piezoelectric element charging circuit 6 shown in FIG. 5,
moreover, at the time of taking images by shifting pixels, the charging
operation is stopped when the charged voltage of the piezoelectric
element becomes as specified, and this charged voltage is held,
and when the charged voltage of the piezoelectric element drops
below the specified value, the charging operation is restarted,
so that the load of the system controller 30 can be lessened.
The piezoelectric element charging circuit 6 shown in FIG. 5 comprises
the charging switch circuit 61 for turning on or off charging of
the piezoelectric element 24, the discharging switch circuit 62
for turning on or off discharging of the piezoelectric element 24,
the voltage dividing resistance 63 for detecting the charged voltage
of the piezoelectric element 24, and the comparator 64 for comparing
the charged voltage of the piezoelectric element 24 detected by
the voltage dividing resistance 63 and the reference voltage, and
the charging switch circuit 61 turns on or off charging of the piezoelectric
element 24 on the basis of the result of comparison of the comparator
64, so that the piezoelectric element charging circuit can be realized
in a simple structure.
In the piezoelectric element charging circuit 6 shown in FIG. 7,
at the time of taking images by shifting pixels, the system controller
30 stops the charging operation when the piezoelectric element 24
reaches the specified voltage, and therefore the charging end can
be controlled by the system controller 30, so that the piezoelectric
element charging circuit can be realized in a small circuit structure.
The piezoelectric element charging circuit 6 shown in FIG. 7 comprises
the charging switch circuit 66 for turning on or off charging of
the piezoelectric element 24, the discharging switch circuit 67
for turning on or off discharging of the piezoelectric element 24,
and the voltage dividing resistance 68 for detecting the charged
voltage of the piezoelectric element 24, and the system controller
64 turns on or off the charging switch circuit 66 on the basis of
the detected voltage of the voltage dividing resistance 68, and
therefore the piezoelectric element charging circuit can be realized
in a simple structure, and the piezoelectric element charging circuit
can be realized in a smaller circuit structure.
In the foregoing explanation, at the time of taking images by shifting
pixels, the first image is taken by charging the piezoelectric element
24 and displacing the imaging device 23, and the second image is
taken by discharging the piezoelectric element 24 and returning
the imaging device 23 to the original position, but the same effects
are obtained in the reverse procedure, that is, by taking the first
image by discharging the piezoelectric element 24 and taking the
second image by charging the piezoelectric element 24.
FIG. 9 is a timing chart explaining the driving and transfer of
the imaging device 24, and the charging and discharging timing of
piezoelectric element, in the case of taking a first image in discharged
state of the piezoelectric element 24 and taking a second image
in charged state of the piezoelectric element 24. In the diagram,
(a) shows operating states of the digital camera, (b) shows vertical
synchronous signal (VD), (c) shows charge sweep pulse (SUB), (d)
shows operation of mechanical shutter, (e) shows charge transfer
(CCDOUT) of the imaging device 23, and (f) shows the voltage applied
to the piezoelectric element 24.
While monitoring as shown in FIG. 9(a), when the release key of
the signal generator 7 is pressed, as shown in FIG. 9(d), the system
controller 30 closes the mechanical shutter, and takes a first image.
In this case, the imaging device 23 is at the initial position (position
P in FIG. 2). After taking the first image, as shown in FIG. 9(e),
the electric charge is transferred from the imaging device 23 in
the sequence of odd line (Odd signal) and even line (Even signal).
After completion of transfer of the electric charge from the imaging
device 23, as shown in FIG. 9(d), the system controller 30 opens
the mechanical shutter, and successively, as shown in FIG. 9(f),
the piezoelectric element 24 is charged. When charging of the piezoelectric
element 24 is over, as shown in FIG. 9(d), the mechanical shutter
is opened to take a second image. In this case, by the charging,
the piezoelectric element 24 is expanded, and the imaging device
23 is displaced by a specified extent (to be at position X in FIG.
2). After taking the second image, as shown in FIG. 9(e), the electric
charge is transferred from the imaging device 23 in the sequence
of odd line (Odd signal) and even line (Even signal), and the piezoelectric
element 24 is discharged spontaneously.
The desired high definition image is obtained by synthesizing the
first and second image data in the pixel shifting processing unit
32, but if operated at high speed by the hardware, the operation
in the unit of 10 seconds is needed for setting of the subject in
order to obtain the next high definition image. When this synthesis
process is done by the software operation of the CPU, it takes the
time in the unit of 10 seconds.
On the other hand, the characteristics of the piezoelectric element
24 is represented by the capacitor of about 0.2 .mu.F, and supposing
the voltage dividing resistance 63 or 68 in FIG. 5 or FIG. 7 used
for obtaining the detected voltage VP to be 1 M.sub.--, if charging
is stopped, the piezoelectric element 24 is spontaneously discharged
in about 0.2 second. Therefore, when the second image is taken in
the charged state of the piezoelectric element 24, by making use
of this spontaneous discharge, the discharging switch circuits 62,
67 in FIG. 5 and FIG. 7 can be omitted.
According to the experiment by the present inventors, when the
piezoelectric element and imaging device are not directly coupled,
that is, without using the mechanism for expanding the displacement
extent of the piezoelectric element, it is confirmed that the piezoelectric
element returns to the initial position, even by a slow discharge
of about 0.2 second, without having effects of friction or the like.
The invention is not limited to the illustrated embodiment alone,
but may be changed or modified within a range not departing from
the true spirit of the invention. For example, in the embodiment,
the internal strobe unit type (the strobe unit circuit 4 in FIG.
1) is explained, but the invention can be similarly applied in the
case of using an external type strobe unit device.
As explained herein, according to the invention as set forth in
one aspect, the imaging device takes a subject image, the piezoelectric
element displaces the imaging device, and energy accumulating means
for supplying an electric power to other unit is used as an electric
power supply source for the piezoelectric element, and therefore
the piezoelectric element can be operated without particularly preparing
boosting circuit in the digital camera.
According to the invention as set forth in another aspect, relating
to one aspect, the energy accumulating means is composed of a main
capacitor for strobe unit emission provided inside or outside, and
the piezoelectric element is charged by the energy accumulated in
this main capacitor, and therefore in addition to the effects of
one aspect, the piezoelectric element can be operated by the main
capacitor for strobe unit emission.
According to the invention as set forth in still another aspect,
the imaging device takes a subject image, the piezoelectric element
displaces the imaging device, the switching means charges the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharges the piezoelectric
element, and the control means controls the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, whereas the control means controls to take a first image
by charging the piezoelectric element in a state of displacing the
imaging device, and take a second image by discharging the piezoelectric
element in a state before displacement of the imaging device, and
therefore the piezoelectric element can be operated without particularly
preparing boosting circuit in the digital camera, and also an image
of high definition can be obtained.
According to the invention as set forth in still another aspect,
the imaging device takes a subject image, a piezoelectric element
displaces the imaging device, switching means charges the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharges the piezoelectric
element, and the control means controls the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, whereas the switching means includes a charge adjusting
circuit for stopping the charging operation when the charged voltage
in the piezoelectric element becomes a specified value to hold this
charged voltage, and restarting charging operation when the charged
voltage in the piezoelectric element becomes lower than a specified
value, and the control means controls to take a first image by charging
the piezoelectric element in a state of displacing the imaging device,
and take a second image by discharging the piezoelectric element
in a state before displacement of the imaging device, and therefore
the piezoelectric element can be operated without particularly preparing
boosting circuit in the digital camera, and also an image of high
definition can be obtained. Moreover, since the charging end is
controlled by the switching means, the load of the control means
is lessened.
According to the invention as set forth in still another aspect,
the imaging device takes a subject image, the piezoelectric element
displaces the imaging device, the switching means charges the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharges the piezoelectric
element, and the control means controls the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, whereas the switching means includes a charging switch
circuit for turning on or off charging of the piezoelectric element,
a discharging switch circuit for turning on or off discharging of
the piezoelectric element, a detecting circuit for detecting the
charged voltage in the piezoelectric element, and comparing means
for comparing the charged voltage in the piezoelectric element detected
by the detecting means and a reference voltage, the charging switch
circuit turns on or off charging of the piezoelectric element on
the basis of the result of comparison by the comparing means, and
the control means controls to take a first image by charging the
piezoelectric element in a state of displacing the imaging device,
and take a second image by discharging the piezoelectric element
in a state before displacement of the imaging device, and therefore
the piezoelectric element can be operated without particularly preparing
boosting circuit in the digital camera, and also an image of high
definition can be obtained. Moreover, since the charging end is
controlled by the comparing means of the switching means, the load
of the control means is lessened.
According to the invention as set forth in still another aspect,
the imaging device takes a subject image, the piezoelectric element
displaces the imaging device, the switching means charges the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharges the piezoelectric
element, and the control means controls the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, whereas the control means controls so as to stop the charging
operation when the piezoelectric element reaches a specified voltage,
and to take a first image by charging the piezoelectric element
in a state of displacing the imaging device, and take a second image
by discharging the piezoelectric element in a state before displacement
of the imaging device, and therefore the piezoelectric element can
be operated without particularly preparing boosting circuit in the
digital camera, and also an image of high definition can be obtained.
Moreover, since the charging end is controlled by the control means,
the switching means is realized in a smaller circuit structure.
According to the invention as set forth in still another aspect,
the imaging device takes a subject image, the piezoelectric element
displaces the imaging device, the switching means charges the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharges the piezoelectric
element, and the control means controls the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, and also controls to stop the charging operation when the
piezoelectric element reaches a specified voltage, whereas the switching
means includes a charging switch circuit for turning on or off charging
of the piezoelectric element, a discharging switch circuit for turning
on or off discharging of the piezoelectric element, and a detecting
circuit for detecting the charged voltage in the piezoelectric element,
and the control means controls to turn on or off the charging switch
circuit on the basis of the detected voltage of the detecting circuit,
and to take a first image by charging the piezoelectric element
in a state of displacing the imaging device, and take a second image
by discharging the piezoelectric element in a state before displacement
of the imaging device, and therefore the piezoelectric element can
be operated without particularly preparing boosting circuit in the
digital camera, and also an image of high definition can be obtained.
Moreover, since the charging end is controlled by the control means,
the switching means is realized in a smaller circuit structure.
According to the invention as set forth in still another aspect,
the imaging device takes a subject image, the piezoelectric element
displaces the imaging device, the switching means charges the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharges the piezoelectric
element, and the control means controls the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, whereas the control means controls to take a first image
in a state not displacing the imaging device, and take a second
image by charging the piezoelectric element in a state of displacing
the imaging device, and therefore the piezoelectric element can
be operated without particularly preparing boosting circuit in the
digital camera, and also an image of high definition can be obtained.
According to the invention as set forth in still another aspect,
the imaging device takes a subject image, the piezoelectric element
displaces the imaging device, the switching means charges the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharges the piezoelectric
element, and the control means controls the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, whereas the switching means includes a charge adjusting
circuit for stopping the charging operation when the charged voltage
in the piezoelectric element becomes a specified value to hold this
charged voltage, and restarting charging operation when the charged
voltage in the piezoelectric element becomes lower than a specified
value, and the control means controls to take a first image in a
state not displacing the imaging device, and take a second image
by charging the piezoelectric element in a state of displacing the
imaging device, and therefore the piezoelectric element can be operated
without particularly preparing boosting circuit in the digital camera,
and also an image of high definition can be obtained. Moreover,
since the charging end is controlled by the switching means, the
load of the control means is lessened.
According to the invention as set forth in still another aspect,
the imaging device takes a subject image, the piezoelectric element
displaces the imaging device, the switching means charges the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharges the piezoelectric
element, and the control means controls the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, whereas the switching means includes a charging switch
circuit for turning on or off charging of the piezoelectric element,
a discharging switch circuit for turning on or off discharging of
the piezoelectric element, a detecting circuit for detecting the
charged voltage in the piezoelectric element, and comparing means
for comparing the charged voltage in the piezoelectric element detected
by the detecting means and a reference voltage, the charging switch
circuit turns on or off charging of the piezoelectric element on
the basis of the result of comparison by the comparing means, and
the control means controls to take a first image in a state not
displacing the imaging device, and take a second image by charging
the piezoelectric element in a state of displacing the imaging device,
and therefore the piezoelectric element can be operated without
particularly preparing boosting circuit in the digital camera, and
also an image of high definition can be obtained. Moreover, since
the charging end is controlled by the comparing means of the switching
means, the load of the control means is lessened.
According to the invention as set forth in still another aspect,
the imaging device takes a subject image, the piezoelectric element
displaces the imaging device, the switching means charges the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharges the piezoelectric
element, and the control means controls the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, whereas the control means controls so as to stop the charging
operation when the piezoelectric element reaches a specified voltage,
and to take a first image in a state not displacing the imaging
device, and take a second image by charging the piezoelectric element
in a state of displacing the imaging device, and therefore the piezoelectric
element can be operated without particularly preparing boosting
circuit in the digital camera, and also an image of high definition
can be obtained. Moreover, since the charging end is controlled
by the control means, the switching means is realized in a smaller
circuit structure.
According to the invention as set forth in still another aspect,
the imaging device takes a subject image, the piezoelectric element
displaces the imaging device, the switching means charges the piezoelectric
element by the energy accumulated in a main capacitor for strobe
unit emission provided inside or outside, or discharges the piezoelectric
element, and the control means controls the switching means for
controlling the charging and discharging sequence of the piezoelectric
element, and also controls to stop the charging operation when the
piezoelectric element reaches a specified voltage, whereas the switching
means includes a charging switch circuit for turning on or off charging
of the piezoelectric element, a discharging switch circuit for turning
on or off discharging of the piezoelectric element, and a detecting
circuit for detecting the charged voltage in the piezoelectric element,
and the control means controls to turn on or off the charging switch
circuit on the basis of the detected voltage of the detecting circuit,
and to take a first image in a state not displacing the imaging
device, and take a second image by charging the piezoelectric element
in a state of displacing the imaging device, and therefore the piezoelectric
element can be operated without particularly preparing boosting
circuit in the digital camera, and also an image of high definition
can be obtained. Moreover, since the charging end is controlled
by the control means, the switching means is realized in a smaller
circuit structure.
The present document incorporates by reference the entire contents
of Japanese priority documents, 11-307635 filed in Japan on Oct.
28, 1999.
Although the invention has been described with respect to a specific
embodiment for a complete and clear disclosure, the appended claims
are not to be thus limited but are to be construed as embodying
all modifications and alternative constructions that may occur to
one skilled in the art which fairly fall within the basic teaching
herein set forth. |