Digital Camera Patent Abstract
A digital camera having a viewfinder includes a zoom control and
switch arrangement that enables a user to zoom in and zoom out of
an object image while visualizing in the viewfinder the optical
and digital zooming effects selected by the user via the switch
arrangement. Digital Camera Patent Claims
I claim:
1. A digital camera having a viewfinder for viewing an object image,
comprising: a zoom control switch arrangement for enabling a user
to zoom in and zoom out of an optical visualization of the object
image; a zoom control responsive to said zoom control switch arrangement
for effecting zooming of the object image in the viewfinder; said
zooming the object image in the viewfinder being an effective zoom
indicative of the effects of optical zoom and digital zoom; wherein
said zoom control switch arrangement includes: a zoom in switch
for generating a zoom in control signal; and a zoom out switch for
generating a zoom out control signal; wherein said zoom control
includes: a primary lens arrangement mounted in a primary light
path for facilitating the capture of the object image with optical
zoom effects; a secondary lens arrangement mounted in a common light
path with the viewfinder for facilitating the visualization of the
object image with optical zoom and digital zoom effects; a motor
arrangement for moving the secondary lens arrangement along at least
a portion of said common light path to help effect the visualization
of the optical zoom effects; said motor arrangement for moving the
secondary lens arrangement along at least another portion of said
common light path to help effect the visualization of the optical
zoom and digital zoom effects; said motor arrangement further for
moving the primary lens arrangement along at least a portion of
said primary light path for helping to effect the capture of the
object image with optical zoom effects; and a microprocessor coupled
to said motor arrangement and responsive to said zoom in control
signal and said zoom out control signal for controlling the movement
of said secondary lens arrangement to effect the visualization of
the optical zoom and digital zoom effects in the viewfinder.
2. A digital camera according to claim 1, further comprising: a
control program for causing said microprocessor to operate in a
predetermined manner in response to said zoom in control signal
and said zoom out control signal; said control program for helping
to cause said primary lens arrangement to move along said at least
a portion of said primary light path to help effect the capture
of the object image with optical zoom effects and for helping to
cause said secondary lens arrangement to move along said at least
a portion of said common light path to help effect visualization
of the object image with optical zoom effects in the viewfinder;
and said control program for further helping to cause said secondary
lens arrangement to move along said at least another portion of
said common light path to help effect visualization of the object
image with optical zoom effects and digital zoom effects in the
viewfinder.
3. A digital camera according to claim 2, wherein said control
program helps facilitate a combined optical zoom effect and digital
zoom effect in a predetermined zoom in order of continuous finite
steps from a 1.times. optical zoom factor by a 1.times. digital
zoom factor to provide an effective 1.times. zoom factor, to a 2.times.
optical zoom factor by a 2.times. digital zoom factor to provide
an effective 4.times. zoom factor.
4. A digital camera comprising: a primary lens system disposed
in a primary light path, said primary lens being moveable between
about a 1.times. optical magnification factor and about a 2.times.
optical magnification factor; a secondary lens system disposed in
a secondary light path, said secondary lens being moveable in tandem
with said primary lens between about another 1.times. optical magnification
factor and another 2.times. optical magnification factor; a viewfinder
disposed in said secondary light path for observing the magnification
of an object to be reproduced digitally, the object being subject
to magnification over a combined optical digital magnification factor
range from about a 1.times. magnification factor to about a 4.times.
magnification factor; a stepper motor coupled to said primary lens
system and to said secondary lens system for moving said secondary
lens system in tandem with said primary lens system between about
said another 1.times. optical magnification factor and about said
another 2.times. optical magnification factor; a microprocessor
coupled to said stepper motor for causing said stepper motor to
move said primary lens system along said primary light path in tandem
with said secondary lens as it moves along said secondary path to
facilitate visualization of the object as it is magnified optically
by aid primary lens; and a control program acting on said microprocessor
to cause said secondary lens system to move along another portion
of said secondary light path to facilitate visualization of the
optical magnification of the object, said secondary lens being movable
along said another portion of said secondary light path between
about said 2.times. optical magnification factor and about a 4.times.
optical magnification factor.
5. A digital camera according to claim 4, further comprising: a
charged coupled device responsive to said microprocessor for causing
the generation of an electrical signal indicative of the object
magnified between about 1.times. digital magnification factor and
said about 2.times. digital magnification factor to facilitate digital
magnification of the object.
6. A digital camera method of visualizing an object to be digitally
captured, comprising: moving a primary lens along at least a portion
of a primary light path to facilitate optical magnification of the
object to be captured between about a 1.times. optical magnification
factor and a 2.times. optical magnification factor; manipulating
an electrical signal to facilitate digital magnification of the
object to be captured between a 1.times. digital magnification factor
and a 2.times. digital magnification factor; and moving a secondary
lens along at least a portion of a secondary light path to facilitate
visualization of the object image with a combined optical zoom and
a digital zoom effects of between about a 1.times.-magnification
factor and about a 4.times.-magnification factor.
7. A digital camera method of visualizing an object according to
claim 6, further comprising: observing in a viewfinder disposed
in said secondary light path said combined optical zoom and digital
zoom effects.
8. A digital camera system, comprising: a digital camera having
a viewfinder and display for viewing an object image; said digital
camera further including: a zoom control switch arrangement for
enabling a user to zoom in and zoom out of an optical visualization
of the object image; and a zoom control responsive to said zoom
control switch arrangement for optically and digitally zooming the
object image in the viewfinder; wherein said zoom control switch
arrangement includes: a zoom in switch for generating a zoom in
control signal; and a zoom out switch for generating a zoom out
control signal; wherein said zoom control includes: a primary lens
arrangement mounted in a primary light path for facilitating the
capture of the object image with optical zoom and digital zoom effects;
a secondary lens arrangement mounted in a common light path with
the viewfinder for facilitating the visualization of the object
image with optical zoom and digital zoom effects; a motor arrangement
for moving the secondary lens arrangement along at least a portion
of said common light path to help effect the visualization of the
optical zoom effects; said motor arrangement motor for moving the
secondary lens arrangement along at least another portion of said
common light path to help effect the visualization of the optical
zoom and digital zoom effects; said motor arrangement further for
moving the primary lens arrangement along at least a portion of
said primary light path for helping to effect the capture of the
object image with optical zoom effects; and a microprocessor coupled
to said motor arrangement and responsive to said zoom in control
signal and said zoom out control signal for controlling the movement
of said secondary lens arrangement to effect the visualization of
the optical zoom and digital zoom effects in the viewfinder.
9. A digital camera system according to claim 8, further comprising:
a control program for causing said microprocessor to operate in
a predetermined manner in response to said zoom in control signal
and said zoom out control signal; said control program for helping
to cause said primary lens arrangement to move along said at least
a portion of said primary light path to help effect the capture
of the object image with optical zoom effects and for helping to
cause said secondary lens arrangement to move along said at least
a portion of said common light path to help effect visualization
of the object image with optical zoom effects in the viewfinder;
and said control program for further helping to cause said secondary
lens arrangement to move along said at least another portion of
said common light path to help effect visualization of the object
image with optical zoom effects and digital zoom effects in the
viewfinder.
10. A digital camera system according to claim 9, wherein said
control program helps facilitate a combined optical zoom effect
and digital zoom effect in a predetermined zoom in order of a 1.times.
optical zoom factor by a 1.times. digital zoom factor to provide
an effective 1.times. zoom factor, to 2.times. optical zoom factor
by a 2.times. digital zoom factor to provide an effective 4.times.
zoom factor.
11. A digital camera system according to claim 10 wherein said
zoom switch arrangement further includes: a selection switch for
enabling a user to select either a viewfinder mode of zoom operation
or a display mode of zoom operation; and wherein said zoom control
is further responsive to said selection switch when actuated in
said viewfinder mode for causing optical and digital zoom operations
with effects viewable in the viewfinder only; and said zoom control
responsive to said selection switch when actuated in said display
mode for causing optical and digital zoom operations with effects
viewable via the viewfinder and the display.
Digital Camera Patent Description
FIELD OF INVENTION
The present invention relates generally to cameras, and more particularly,
to a digital camera having a combined optical zoom and digital zoom
feature.
BACKGROUND OF THE INVENTION
In general, both digital and analog cameras must give feedback
to a user of what area of a scene to be photographed will be captured
when a picture is taken. This has traditionally been accomplished
using a built-in device called an optical viewfinder an optical
window that enables the user to visualize the scene and see exactly
what area of the scene will be captured by the camera lens system.
In order to change the area to be captured by the camera lens system,
many digital and analog cameras also include what is commonly called
a zoom feature. The zoom feature is limited to optical zooming in
the analog camera but may include both optical zooming and digital
zooming in a digital camera.
Before discussing the merits of optical and digital zooming, it
may be beneficial to briefly review the difference between what
is known in the state of the art as a through the lens (TTL) camera
and a point and shoot (PAS) camera.
In the TTL camera, as a user views a scene to be photographed he
or she utilizes the camera viewfinder. More particularly, the user
is viewing the scene through the lens system of the camera. That
is, with the help of an internally positioned mirror within the
TTL camera, the light passing through the lens system is reflected
by the internal mirror and directed to the optical viewfinder for
consideration by the user. When the user is satisfied with the scene
to be captured, the mirror is repositioned allowing a direct light
path to the photosensitive plane of the camera, and thus, allowing
the scene to be captured as viewed through the optical viewfinder.
The PAS camera is much less expensive and does not allow the user
to view the scene through the primary lens system. Instead, the
optical viewfinder is provided with a secondary lens system that
moves in and out in tandem with the primary lens system. In short
then, in the PSA camera two separate light paths are established;
one light path for the primary lens system to the photosensitive
plane of the camera and another light path through the secondary
lens system to the viewfinder for the scene preview benefit of the
user.
Considering now the merits of the two types of zooming, optical
zooming and digital zooming, it will be understood by those skilled
in the art that optical zooming is a mechanical operation that affects
movement of the primary lens system so as to enlarge or reduce a
viewed object. Thus, for example, by moving the primary lens system
a user may, in a smooth mechanical transition, view a group arrangement
of flowers down to a single flower within the group and then back
to the entire arrangement. This transition is commonly called "zooming
in" and "zooming out" of the scene.
With the advent of digital cameras and photography, two new developments
emerged: imaging view display modules, known as liquid crystal display
(LCD) units and digital zooming. With the LCD unit, a user is able
to independently view the scene both before the image is captured,
in a preview mode of operation, and after the image has been captured
and stored, in a post-view or review mode of operation. In short
then, the preview mode of operation is essentially the same mode
of operation found in a TTL type of camera as the image displayed
on the LCD is taken directly from the photosensitive plane of the
digital camera that is otherwise called a charged couple device
(CCD).
Digital zooming is an electrical manipulation that selects a portion
of the image converted by the CCD so that the selected portion appears
to be enlarged when viewed on the whole viewing area of the LCD.
From the foregoing, it will be understood by those skilled in the
art that the same effects of optical zooming can be achieved and
viewed on the LCD without having to incur the high costs associated
with providing a moving primary lens system. The trade off for such
a benefit however, is degradation in the image quality as viewed
on the LCD as the CCD utilizes fewer pixel locations.
In certain high end digital cameras, the degradation in image quality
brought about by digital zooming is overcome by providing a conventional
optical zooming feature. In this type of camera, the viewfinder
tracks the camera lens to enable the user to visually see the effects
of the optical zooming. Alternatively, the user may also view the
effects of the optical zooming on the LCD in the preview mode of
operation as the magnification is achieved by the primary lens system
prior to the object image being converted by the CCD. In most situations
however, the user will not utilize the LCD for the purpose of observing
optical zooming as LCD use places a high electrical drain on the
battery system of the camera.
Recently, certain digital cameras have been offered providing both
optical and digital zooming. In such cameras, the user is able to
select which one of the effects is desired to arrive at a desired
magnification. Thus, for example to arrive at a 4.times.-magnification
factor a user could select a 2.times. optical effect and a 2.times.
digital effect.
While such combined effects are desirable in the preview mode of
operation, the combined zooming effect has been less than desirable
due to the high electrical drain on the camera battery system. That
is as the user gets the "what you see is what you get"
view of image data only by viewing the LCD image there is a constant
power drain when the combined zoom effect is in operation.
From the foregoing, it should be understood that when the LCD is
powered off, the user is limited to viewing only the optical zooming
effects through the viewfinder. In this regard, in prior art digital
camera with combined zoom features, the optical zoom is always enabled
while the digital zoom is only enabled when the LCD is in a powered
up state of operation. In this manner, the user would never be in
a situation of guessing at what exactly is included in the scene
to be captured.
While the above discussed cameras and methods of operation provide
the combined effects of both optical and digital zooming, the effects
of the digital zooming significantly reduce the useful operating
period of the camera relative to the available battery power source.
In other words, with a combined optical and digital zooming feature
camera, the costs of operating the camera are significantly higher
as expensive batteries must be replaced on a much more frequent
basis.
Therefore it would be highly desirable to have a new and improved
digital camera that includes both optical and digital zooming features
while simultaneously facilitating low battery drainage. Such a new
and improved digital camera should also be easy to use always permitting
the user to know exactly what scene will be captured for image reproduction
purposes whether operating in an optical zoom mode or a digital
zoom mode.
DISCLOSURE OF THE INVENTION
In accordance with the present invention, a digital camera includes
a zoom features that combines both optical zooming and digital zooming
without requiring the use of a liquid crystal display (LCD) unit
and thus, facilitates low battery drainage. The new and improved
digital camera includes a motor activated primary lens and secondary
lens system that operate in tandem over the optical zoom range of
the camera. The user views the effects of the optical zoom through
a viewfinder that sees the scene to be photographed through the
secondary lens system. At the end of the optical zoom range the
motor continues to drive the secondary lens system to provide the
user with an optical simulation of the digital zoom effects. In
short, the user is able to visualize a zoom factor indicative of
the product of various optical and digital zoom factors without
activation of a LCD unit. In the alternative, the LCD unit may be
activated to permit the user to see the combined effects of optical
and digital zooming in a preview mode of operation using the LCD
unit. In the zoom mode of operation a zoom control algorithm facilitates
a process wherein a microprocessor generates electrical signals
to control the motor operation to provide the whole of both the
optical zoom range and the digital zoom range in accordance with
the novel method of using the digital camera.
BRIEF DESCRIPTION OF DRAWINGS
The above mentioned features of the present invention and the manner
of attaining them will become apparent and the invention itself
will be best understood by reference to the following description
of the preferred embodiment of the invention, in conjunction with
the accompanying drawings, wherein:
FIG. 1 is a diagrammatic representation of a digital camera that
is constructed in accordance with the preferred embodiment of the
present invention;
FIG. 2 is a block diagram of the digital camera of FIG. 1 illustrating
its use with a data processing system;
FIG. 3 is a high-level zoom control flow chart illustrating the
operational steps of the digital camera of FIG. 1;
FIG. 4 is a high-level aperture setting flow chart illustrating
the operational steps of the digital camera of FIG. 1;
FIG. 5 is a high-level fixed focus mode flow chart illustrating
the operational steps of the digital camera of FIG. 1;
FIG. 6 is a diagrammatic representation of a front face view of
an aperture lens arrangement within the digital camera of FIG. 1;
FIG. 7 is a graphical representation of admitted light intensity
vs. lens movement within the digital camera of FIG. 1; and
FIG. 8 is a high-level auto focus mode flow chart illustrating
the operational steps of the digital camera of FIG. 1.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring now to the drawings and more particularly to FIGS. 1-2,
there is illustrated a digital camera system 8 which is constructed
in accordance with the present invention. The digital camera system
8 captures and processes digital images for permanent or temporary
view by a user.
Considering now the digital camera system 8 in greater detail with
reference to FIGS. 1-2, the digital camera system 8 generally includes
a data processing and printing system 9 for receiving and processing
image data, and a digital camera 10 for capturing and storing the
image data to be processed by the system 9. The data processing
and printing system 9 can be configured in various hardware and
software configurations that facilitates digital image processing
such as a personal computer system having a processor or computer,
a monitor, a digital card reader and a printer or a stand alone
photo-printer having an IR port, a digital card reader and an internal
micro-processor that permits image data received on a storage card
module 54 or transmitted on an infrared wavelength via an IR communication
channel, such as an IR channel indicated generally at 75 (FIG. 2).
In operation, the user utilizing the digital camera 10, selects
a scene to be photographed and frames and focuses the image using
the various camera controls that will be described hereinafter in
greater detail so that the object scene can be captured and stored
when the camera 10 is activated. Once the image has been captured
and stored by the camera 10, the user can select the image either
by itself or with other images that have been previously captured
and stored to cause them to either be transmitted to the processing
system 9 via the IR channel 75 or copy them to the storage card
module 54 with various instruction commands such as how many of
prints of each image are to be prepared, cropping instructions,
rotating instruction, thumbnail instructions and the like. The storage
card module 54 can then be removed from the camera 10 and inserted
in the data processing and printing system digital card reader for
processing purposes. More particularly, the image information and
instructions when received by the processing system 9 are acted
upon resulting in the preparation of image prints in accordance
with the instructions of the user as entered via the camera 10.
Referring now to the drawings and more particularly to FIG. 1,
there is shown in diagrammatic representation the digital camera
10, which is, constructed in accordance with the present invention.
The camera 10 is configured for use with the image processing system
9 to facilitate the review, formatting and printing of high quality
digital photographs. In the preferred embodiment of the present
invention, the camera 10 includes both optical and digital zooming
features as well as a fixed focus feature and an automatic focus
feature, each of which will be described hereinafter in greater
detail when the operation of the camera 10 is described.
The combined optical and digital zoom features are implemented
with a significant reduction in the battery power drain of the camera
10 as will be further explained. The fixed focus mode of operation
is aperture sensitive, allowing the camera 10 to default to the
fixed focus mode of operation. In the fixed focus mode of operation,
the camera 10 automatically adjusts its focal point and aperture
setting relative to the amount of ambient light being received by
the camera 10.
Considering the camera 10 in greater detail with reference to FIG.
1, the camera 10 generally includes a housing 16 having mounted
therein a aperture/lens system or arrangement 13 that facilitates
the zooming feature, aperture setting for light adjustments and
the focusing features for image reproduction purposes. In this regard,
the aperture/lens arrangement 13 generally includes a primary lens
system indicated generally at 14 for focusing and optical zooming
in and out of a scene to be captured, a shutter 19 for allowing
the light indicative of the object to be captured to enter the photosensitive
plane of the camera and an aperture 18 that is automatically adjusted
for receiving the proper amount of light to assure proper image
formation.
In order to allow the user to preview the scene to be captured,
the camera 10 also includes a microprocessor 25 and liquid crystal
display (LCD) unit 38 that are coupled electrically to a charged
coupled device or CCD 15. The LCD unit 38 permits the user to visualize
various message indications relative to camera control as well as
previewing the effects of both optical and digital zooming before
an image is captured. The CCD 15 is disposed in the primary light
path for converting light to an electrical signal that is ultimately
processed by the microprocessor 25 as will be explained hereinafter
in greater detail. As best seen in FIG. 1, the primary light path
extends from the aperture 18 to the charged couple device 15 via
the primary lens system 14 and the shutter 19.
The microprocessor 25 and LCD unit 38 operate to provide one preview
mode of operation that is substantially the same mode of operation
as found in a through the lens (TTL) digital camera. That is, the
user via the LCD unit 38 can view the effects of both optical zooming
and digital zooming when the LCD unit 38 is placed in a power on
condition. It will be appreciated however, by those skilled in the
art, that in this LCD preview mode of operation, the LCD unit 38
places a significant battery drain on the electrical system of the
camera 10.
The camera 10 also includes a zoom effect viewfinder arrangement
43 having a secondary lens system 44 and viewfinder 45. The viewfinder
arrangement 43 operates in cooperation with a zooming algorithm
300, to provide the user with, in another preview mode of operation,
a visualization of the object scene that will be captured. In this
mode of operation, the user is able to visualize the object scene
with no power applied to the LCD unit 38 to effect a significant
increase in the operating period of the camera. In short then, in
this viewfinder preview mode of operation, the LCD unit 38 does
not exert a power drain on the electrical system of the camera 10
as the LCD unit 38 is not placed in a power on condition. A selection
switch 33 allows a user to select a desired mode of operation: a
viewfinder only mode of operation or a viewfinder and LCD unit mode
of operation. In the viewfinder only mode of operation, a switch
30, forming part of a switch arrangement with switch 33, is set
active. In the combined mode of operation, an LCD active switch
32, also forming part of the switch arrangement with switch 33,
is set active. The selection switch 33 then functions as a zoom
in and zoom out switch or a mode selection switch.
A stepper motor 29 coupled between the microprocessor 25 and the
primary and secondary lens systems 14 and 44 respectively, causes
the respective lens systems 14 and 44 to be moved for focusing and
zooming purposes. The stepper motor 29 under the control of the
microprocessor 25 and a fixed focus control algorithm 100 (FIG.
5) incrementally adjusts focal point of the primary lens system
14 when the camera 10 is operating in the fixed focus mode of operation.
The stepper motor 29 under the control of the microprocessor 25
and the zoom control algorithm 300 also zooms the primary lens system
14 and the secondary lens system 44 over an optical zoom range between
1.times. magnification and 2.times. magnification. At the end of
the optical zoom range, when the primary lens system 14 can no longer
effect any greater zooming effects, the microprocessor 25 causes
the stepper motor 29 to continue to move the secondary lens system
44 in such a manner as to simulate digital zooming effects that
are directly viewable by the user without activating the LCD unit
38. That is, the secondary lens system 44 will continue to magnify
the object scene as viewed in the viewfinder 43, even though the
primary lens system 14 is no longer moving. In short then, the amount
of magnification the optical viewfinder 43 will show is the product
of the optical and digital zoom factors as shown in Table A.
For example, the optical zoom function has an operating range from
about Z.sub.1 to about Z.sub.n which is expressed in a series of
finite steps as Z.sub.1, Z.sub.2, Z.sub.3, . . . Z.sub.n. Thus,
in optical zoom operations, the primary lens system 14 and the secondary
lens system 44 move in tandem along their respective primary and
secondary light paths in a series of continuous finite steps from
Z.sub.1 to Z.sub.n when the user zooms in to obtain a telescopic
object image. Conversely, when the user zooms out to obtain a wide
angle object image, the lens systems 14,44 move in an opposite direction
in a continuous series of finite steps from Z.sub.n to Z.sub.1.
Once the primary lens system 14 has been moved to its maximum optical
zoom position at Z.sub.n, no further optical zoom is possible. In
this regard, if the user desires to continue to zoom in on an object
image, the camera 10 automatically switches to the digital zoom
mode.
In the digital zoom mode there is another series of finite magnification
factor steps as D.sub.1, D.sub.2, D.sub.3, . . . D.sub.n to provide
a continuous range from about D.sub.1 to D.sub.n. In this mode of
operation, the microprocessor 25 causes the CCD 15 to manipulate
its output signal to provide the effects of digital zooming that
may be observed on the LCD unit 38 if the camera is operating in
the LCD active mode. The practical effects of what is viewed on
the LCD unit 38 is the product of the current optical zoom factor
(for example Z.sub.n) and the current digital zoom factor (for example
D.sub.n) to provide the overall effective zoom factor of Z.sub.n
D.sub.n.
To permit the user to visualize this zooming effect in the viewfinder
45, the microprocessor 25, under the control of a zoom control program
300, causes the secondary lens system 44 to continue movement along
the secondary light path from the maximum optical zoom position
of Z.sub.n to a maximum effective zoom position of Z.sub.n D.sub.n.
In short then, as the secondary lens system 44 travels along the
secondary light path, the lens moves in a series of finite steps
that simulate the optical digital zoom factor products that range
from Z.sub.1 D.sub.1 as a minimum effective zoom product to Z.sub.n
D.sub.n as a maximum effective zoom product.
In the preferred mode of operation, the microprocessor 25 in response
to the zoom in signal produced by the zoom switch 33 calculates
the product of the current optical zoom factor and the current digital
zoom factor to determine the positions that the stepper motor 29
needs to move the respective primary lens 14 and secondary lens
44. Thus for example, if the current optical zoom factor position
is Z.sub.4 and the current digital zoom factor position is D.sub.2
the microprocessor 25 will cause the secondary lens system 44 to
move to a position that simulates the effective optical digital
zoom product of Z.sub.4 D.sub.2. As mentioned earlier Table A illustrates
the effective zoom factors.
TABLE A Optical Zoom Digital Zoom Effective Zoom Product Z1 D1
Z1D1 Z2 D1 Z2D1 Z3 D1 Z3D1 . . . ZN D1 ZND1 ZN D2 ZND2 . . . . .
. . . . ZN DN ZNDN
Table B illustrates a series of different effective zoom magnification
factors based on current optical zoom magnification factors and
current digital zoom factors.
TABLE B Ef- Optical Digital fective Zoom Zoom Zoom 1 X 1 X 1 X
1.5 X 1 X 1.5 X 2 X 1 X 2 X 2 X 1.5 X 3 X 2 X 2 X 4 X
From the foregoing, it should be understood by those skilled in
the art that this approach improves ease of use for the user as
the effects of optical zoom and digital zooming can be viewed through
the viewfinder 43 or in the alternative, on the LCD unit 38 if the
user so chooses to activated this device. As a further benefit,
the use of the viewfinder 43 and secondary lens system 44 masks
the need to know when one is optical zooming and digital zooming
which concepts are difficult for the average user to comprehend.
Although in the preferred mode of operation the camera 10 has been
described as including a stepper motor 29 to effect len movements,
those skilled in the art will appreciate that other forms of motive
means such as ac and dc motors can be utilized to effect such movement.
Thus, there is no intention of limiting the scope of the present
invention to merely a stepper motor.
It will also be appreciated by those skilled in the art that different
switch arrangements may be utilized. For example a four to six switch
arrangement could provide separate switches for optical zoom in,
optical zoom out, digital zoom in, digital zoom out, viewfinder
mode, LCD mode functions. As another example a single zoom in zoom
out switch could be coupled with a three switch arrangement to select
an optical zoom mode, a digital zoom mode and a LCD mode, where
the viewfinder mode would be a default mode. Thus, as many different
types and kinds of switches as well as menu selection functions
are contemplated within the true scope of the present invention
there is no intention of limiting the invention to the switch arrange
as shown and described.
Considering now the zooming algorithm 300 in greater detail with
reference to FIG. 3, the zooming algorithm 300 begins at a start
command 302 whenever power is applied to the camera 10. The program
immediately advances to a command step 304 that causes the viewfinder
zoom switch 32 to be set to an active state and the LCD zoom switch
30 to an inactive state. The program then advances to a command
step 306 that set a setting in the internal memory 84 to 1 that
establishes an optical zoom factor at a 1.times. magnification and
a digital zoom factor to 1.times. magnification to provide an overall
1.times.-combine magnification.
After the optical and digital zoom factors have been set, the program
proceeds to a command step 308 that causes a motor control algorithm
500 to drive the stepper motor 29 so that the primary lens system
14 and the secondary lens system 44 are both moved in tandem to
provide a 1.times. magnification factor. As motor drivers are conventional
and well known to those skilled in the art the motor control algorithm
500 will not be described hereinafter in greater detail.
After the magnification factors have been set, the program proceeds
to a determination step 309 to verify that the lenses have been
adjusted. The program loops at step 309 until the stepper motor
29 has adjusted the lenses 14 and 44 to their proper positions.
Next the program goes to a determination step 310 to determine whether
the user has activated the zoom switch 33 to change the operation
mode from the viewfinder mode to the LCD mode. If the user has not
activated the mode switch 33 to change modes, the program proceeds
to a determination step 312 to sense whether the user desires to
power down the camera 10. If the user desires to power down the
camera 10, the program then proceeds to an end step 314 and powers
down the camera 10. If the user has not activated the power switch,
the program jumps to the determination step 316 and proceeds as
will be described hereinafter. Stated otherwise, the camera 10 is
now in a ready state waiting for the user to activate the zoom switch
33 to either increase or decrease the zoom settings.
At the determination step 312, if a determination is made that
the user has not initiated a power camera down sequence, the program
advances to another determination step 316 to determine whether
the user is attempting to increase or decrease the zoom factors.
If the user is attempting to increase zooming, the program branches
to a call step 318 that calls an increase zoom subroutine 340. The
increase zoom subroutine 340 increases the zoom magnification factors
so long as the user continues to hold the zoom switch 33 in an increase
zooming state. On the other hand, if the user is attempting to decrease
zooming, the program branches to another call step 320 that calls
the decrease zoom subroutine 360. The decrease zoom subroutine 360
decreases the zoom magnification factors so long as the user continues
to hold the zoom switch 33 in a decrease zooming state.
Considering now the increase zoom subroutine 340 in greater detail
with reference to FIG. 3, the increase zoom subroutine 340 begins
at a start step 342 that is entered from the call step 318. The
subroutine then goes to a command step 344 that determines the current
optical zoom and digital zoom settings. The subroutine then proceeds
to a determination step 346 to determine whether the current settings
are set to a maximum setting of N If the current settings are set
to N, the camera 10 is set to its maximum zoom factors that provide
a maximum of a combine optical zoom and digital zoom of a 4.times.-magnification
factor. In this regard, no further magnification is possible and
the subroutine exits via a go to step 359 to the main program at
step 310 and continues as previously described.
If the current setting is not set to the maximum (N), the program
advances to a command step 350 that increments the current setting
by one. Next the subroutine proceeds to a command step 352 that
causes the stepper motor 29 to move the secondary lens system 44
to its appropriate position to achieve the desired magnification
factor established by the setting. The subroutine then goes to a
determination step 354 to verify that the secondary lens 44 has
been moved. The subroutine then goes to a determination step 356
to determine whether the primary lens 14 needs to be adjusted to
provide the overall effective magnification as determined by the
current settings. If an adjustment is necessary the subroutine activates
the stepper motor 29 and advances to step 358 to wait for the stepper
motor 29 to adjust the position of the primary lens 14. Once the
primary lens 14 has been properly positioned, the program proceeds
to the go to step 359 and proceeds as previously described.
If a determination is made at step 356 that the primary lens 14
does not need to be adjusted to effect the overall magnification
factor as set, the subroutine then returns to the main program at
step 310 via the go to step 359 and continues as previously described.
Considering now the decrease zoom subroutine 360 in greater detail
with reference to FIG. 3, the decrease zoom subroutine 360 begins
at a start step 362 that is entered from the call command 320. The
subroutine then proceeds to a command step 364 that retrieves the
current settings. Next the program goes to a determination step
366 that determines whether the current setting for zoom factors
is set to the minimum setting of a 1.times. magnification factor.
If the system is set to the minimum value of 1, the camera is set
to its minimum factors to provide a minimum 1.times. combined magnification
factor. In this regard, no further decrease in magnification is
possible and the subroutine exits, via a go to step 379 to the main
program at step 310 and continues as previously described.
If the current setting is not set to 1, the subroutine advances
to a command step 370 that decreases the current setting by one.
Next the subroutine proceeds to a command step 372 that causes the
stepper motor 29 to move secondary lens system 44 to its appropriate
position to achieve the desired magnification factor established
by the new setting. The subroutine waits at a determination step
374 for the lens 44 to be adjusted. Once the secondary lens 44 has
been adjusted the subroutine then advances to a determination step
376 to determine whether the primary lens 14 needs to be adjusted
to effect the magnification factor determined by the current setting.
If no adjust is necessary the subroutine go to the main program
at step 310 via the go to step 379 and continues as previously described.
If at step 376 a determination has been made that the primary lens
14 needs to be repositioned, the stepper motor 29 is activated and
the program advances to a determination step 378 to verify that
the primary lens 14 has been repositioned. The subroutine waits
at step 378 until the primary lens has been adjusted. The subroutine
then advances to the go to step 379 and proceeds as described previously.
From the foregoing it should be understood that the user can zoom
in or zoom out visualizing the effects of both optical and digital
zooming either using the viewfinder 45 or the LCD 38 depending upon
which operating mode the user has selected.
Considering now the focusing of the camera 10 in greater detail
with reference to FIG. 1, the camera 10 includes a fixed focus mode
of operation as well as an automatic focus mode of operation. In
the fixed focus mode, the camera 10 as will be explained hereinafter
in greater detail automatically adjusts its focal point and aperture
setting relative to the amount of ambient light being received through
the primary lens system 14 of the camera 10.
In order to facilitate the fixed focus mode and the automatic focus
modes of operation, the camera 10 includes the adjustable aperture
18 that cooperates with the primary lens arrangement 14 and the
shutter 19 for admitting light to the charged couple device 15 for
a predetermined period of time. The charged couple device 15 converts
the light that is received into an electrical signal that is indicative
of an object to be photographed as well as the ambient light conditions
surrounding the object.
An analog to digital converter 56 converts the electrical signal
generated by the charged couple device 15 into a digital signal
that is coupled to the microprocessor 25. The microprocessor 25
through various ones of the algorithms embodied therein, as will
be explained hereinafter in greater detail, automatically places
the camera 10 in the fixed mode of operation upon the camera being
activated. The microprocessor 25 also causes the aperture 18 of
the camera 10 to be adjusted to an optimal setting and then automatically
adjusts the focal point of the camera 10 to facilitate ease of use
by the camera user. More specifically these automatic adjustments
and setting are achieved through an a fixed focus mode algorithm
100 (FIG.5), an automatic focus mode algorithm 200 (FIG. 11) and
an aperture control algorithm 400, (FIG.4) each of which, will be
described hereinafter in greater detail.
Considering now the fixed focus mode algorithm 100 in greater detail
with reference to FIG. 5, the fixed focus mode algorithm 100 is
responsive to the optimal setting of the aperture 18 as determined
by the aperture control algorithm 400, and automatically moves the
primary lens system 14 to a predetermined focal point. In the fixed
focus mode of operation, the following operational steps are achieved:
1. The algorithm 100 causes the shutter 19 to be opened allowing
the microprocessor 25 to receive a digital signal indicative of
the ambient lighting conditions. 2. The algorithm 100 based on the
determined ambient lighting conditions determines an appropriate
shutter speed and aperture size for facilitating the capturing of
a properly exposed image object. 3. The algorithm 100 based on the
determined aperture size causes the primary lens 14 to be moved
to a predetermined focal point for proper focusing of the image
object to be captured. Each aperture size has a corresponding focal
point. Thus, since there are three different aperture size settings
there are three corresponding focal point settings in the fixed
focus mode of operation. A look up table stored in the internal
memory storage device 84 is accessed by microprocessor 25 so that
it retrieves a proper focal point setting based upon the aperture
size determined by the algorithm 400. Since the camera 10 has the
capability of using aperture size to maximize the range within which
an object is located, and still be in focus the camera 10 is referred
to as "aperture sensitive". This is an important feature
of the camera 10 as the fixed focus mode of operation is the default
mode. Such a default mode saves a substantial amount of time in
comparison to prior art cameras that power up in an automatic focus
mode, as only one primary lens movement is required.
Considering now the fixed focus mode algorithm 100 in still greater
detail with reference to FIG. 5, the fixed focus mode algorithm
100 begins at a start command 102 when power is applied to the camera
10. The program then proceeds to a command instruction 104 that
places the camera 10 in the fixed focus mode of operation changing
the focus switch 31 from its normally neutral position to a fixed
focus mode setting indicated at 26.
From the command instruction 104 the program goes to a determination
step 105 to wait for the user to activate the shutter button 36
to a 1/2 way position to initiate an adjustment. The program advances
from step 105 to a command step 106 when the shutter button 36 has
been depressed to the adjust position. Step 106 causes the shutter
19 to be fully opened exposing the CCD 15 to the ambient lighting
conditions via the primary lens system 14. Once the microprocessor
25 receives the digital signal indicative of the ambient lighting
conditions, the program advances to a call command step 108 that
calls the algorithm 400 that calculates a proper aperture setting
and shutter speed based upon the strength of the ambient light signal
received by the microprocessor 25. The aperture shutter speed control
algorithm 400 will be discussed hereinafter in greater detail.
After the aperture setting and shutter speed has been determined
by reference to a simple look up table, via the algorithm 400, the
program returns to the fixed focus mode algorithm at a command step
110 that causes the stepper motor 29 to adjust the size of the aperture
to a determined one of its three primary aperture settings indicated
at 20,21, and 22 respectively. The program then proceeds to a determination
step 112 to verify that the aperture 18 has been set to its proper
setting.
Once the aperture 18 has been adjusted, the program proceeds to
a command step 116 that retrieves from a look up table in the internal
memory 84 a focal point setting. From the command step 116 the program
advances to a command step 118 that causes the stepper motor 29
to move the primary lens system 14 to the retrieve focal point setting.
The program goes to a determination step 120 that determines whether
the lens 14 has been adjusted. Once the lens focal point is set,
the program proceeds to an end command 122.
Considering now the automatic focus mode algorithm 200 in greater
detail with reference to FIG. 11, in order to place the camera 10
in the automatic focus mode of operation, the user toggles the focus
from its normally fixed focus position at 26 to an automatic focus
mode setting indicated at 28. Once the camera 10 is placed in the
automatic focus mode, the user is free to depress a shutter release
button or switch 34 to an initial half way stop position for generating
an electrical signal that causes the microprocessor 25 to execute
the automatic focus mode algorithm 200. In the automatic focus mode
of operation, the following operational steps are achieved while
the shutter release button is disposed at its initial half way stop
position: 1. The algorithm 200 causes the shutter 19 to be opened
allowing the microprocessor 25 to receive a digital signal indicative
of the ambient lighting conditions. 2. The algorithm 200 causes
the LCD 38 to provide a new indication to the user, such as a blinking
indication, that the primary lens system 14 has been adjusted to
the proper focal point. Once the user sees this new indication,
the shutter release button 34 may be fully depressed resulting in
the capturing and storing of a digital image in proper focus.
The setting determined in the above described procedure are maintained
for subsequent shutter actuation to facilitate ease of use by the
user.
Considering now the auto focus mode algorithm 200 in still greater
detail with reference to FIG. 11, the auto focus mode algorithm
200 begins at a start command 202 when power is applied to the camera
10. The program then proceeds to a determination step 204 to detect
whether the user has activated the focus switch 31 to place the
camera in the auto focus mode of operation. In this regard, the
program loops at the determination step 204 until the user activates
the toggle switch 31 to place the camera in the auto focus mode.
From the determination step 204 the program proceeds a determination
step 206 to wait for the user to depress the shutter button 34 to
its halfway stop point. When the user depresses the shutter button
34 to its half way stop point, the program advances to a command
step 208 that causes the shutter 19 to b e fully opened exposing
the CCD 15 to the ambient lighting conditions via the primary lens
system 14. Once the microprocessor 25 receives the digital signal
indicative of the ambient lighting conditions, the program advances
to a call command step 210 that calls the algorithm 400 that determines
a shutter speed and proper aperture setting based upon the strength
of the ambient light signal received by the microprocessor 25.
After the aperture setting and shutter speed has been determined
in algorithm 400, the program returns to the auto focus mode algorithm
200 at a command step 212 that causes the stepper motor 29 to close
the shutter 19 and to adjust the size of the aperture to the determined
one of its three primary aperture settings indicated at 20,21, and
22 respectively. The program then proceeds to a determination step
214 to verify that the aperture 18 has been set to its proper setting.
Once the aperture 18 has been adjusted, the program proceeds to
a command step 216 that calculates a proper shutter speed for the
determined aperture setting. The shutter speed is stored in the
internal memory 84 of the microprocessor. The program then advances
to a call step 218 that calculates a focal point position for the
primary lens 14 based upon the amount of ambient light being received
by the CCD 15. This determination is made so the CCD 15 will receive
the maximum amount of light possible based on the current ambient
light conditions. The algorithm that calculates the focal point
position is well known to those skilled in the art and will not
be described hereinafter in greater detail. The program then goes
to a command step 220 that causes the stepper motor 29 to advance
the lens system 14 to the determined position.
Next the program proceeds to a determination step 222 to wait for
the lens system 14 to be moved to its proper position. Once the
lens system 14 has been adjusted the program goes to a command step
224 that causes the LCD unit 38 to blink at a desired blink frequency
to provide the user with an indication that the lens system 14 has
been adjusted and that the camera is now in a ready state for a
photograph to be taken.
The program then goes to a determination step 226 to wait for the
user to fully depress the shutter button 34. In this regard, when
the user fully depresses the shutter button 34 the program advances
from the determination step 226 to an activate command 228 that
activates the shutter 19 at the determined shutter speed to expose
the CCD 15.
The program then goes to a determination step 230 to verify whether
or not the user has activated the focus switch 31 to change the
camera back to the fixed focus mode of operation. If it is determined
that the user has changed the mode of operation, the program proceeds
to the fixed focus mode algorithm 100 at the command 105 where the
program proceeds as described previously.
If a determination is made at step 230 that the user desires to
continue operating in the auto focus mode of operation, the program
goes to a determination step 234 to determine when the user desires
to power down the camera 10. If the user desires to power down the
camera 10, the program advances to an end step 236 to exit the auto
focus algorithm 200. If the user does not desire to power down the
camera, the program goes to a go to step 238 that returns to the
determination step 206 to wait for the user to again depress the
shutter button 34. In this manner, the camera remains adjusted for
continuous shooting of additional images until the user either changes
the auto focus mode to the fixed focus mode or the camera is powered
down to an off power condition.
Considering now the aperture control algorithm 400 in greater detail,
the aperture control algorithm is responsive to the digital signal
provided through the analog to digital converter 56 an automatically
adjusts the aperture 18 to an optimal setting relative to the amount
of ambient light conditions surrounding the object to be photographed.
In this regard, the algorithm 400 is entered at a start command
402 (FIG.4) from either the call command 108 in the fixed focus
mode algorithm 100 or the call command 216 in the auto focus mode
algorithm 200. The program then proceeds to a command 404 that determines
the proper aperture setting for the given or measured ambient light
conditions.
Once the proper aperture setting has been determined at step 404,
the program goes to another determination step 405 to determine
a shutter speed base on the determined aperture setting. The program
then advances to a move command at step 406 that causes the stepper
motor 29 to move the aperture 18 to one of its three primary positions
as best seen in FIG. 9. The aperture settings are conventional camera
settings of 2.8, 5.6, and 11 which settings are indicated generally
at 20,21 and 22 respectively. The program then goes to a return
step 408 that returns the program to the active focus control 100
or 200 depending upon which focus mode the camera 10 was set to
operate. If the camera is operating in the fixed mode the program
advances to step 110, in the fixed focus mode algorithm 100, otherwise
the program advances to step 212 in the auto focus algorithm 200.
While particular embodiments of the present invention have been
disclosed, it is to be understood that various different modifications
are possible and are contemplated within the true spirit and scope
of the appended claims. There is no intention, therefore, of limitations
to the exact abstract or disclosure herein presented.
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