Digital Camera Patent AbstractA determination is made as to whether or not the magnification set
for image sensing is greater than the upper limit of the optical
finder. When the set magnification is greater, the original image
is subjected to a thinness process, the LCD is automatically turned
ON, and the image is displayed. When using electronic zoom, an image
of the photographic object corresponding to the effective image
sensing magnification is displayed on the LCD 10, thereby avoiding
impairing the compactness of the digital camera allowing easy confirmation
of the photographic object, and allowing easy framing without providing
a large optical finder.
Digital Camera Patent ClaimsWhat is claimed is:
1. A digital camera comprising: an optical finder for optically
viewing a photographic object; an electronic finder for electronically
displaying a photographic object; an operation member for performing
an electronic zoom; a switching member for switching between an
activated state and a deactivated state of the electronic finder;
a zooming lens for image sensing; and a controller for setting the
electronic finder to the activated state forcedly when an effective
magnification of one or both an optical zoom of said zoom lens or
said electronic zoom is less than a minimum or more than a maximum
possible magnification of said optical finder.
2. A digital camera as claimed in claim 1, wherein the controller
sets the electronic finder to the activated state forcedly, even
if the electronic view finder had been manually turned off.
3. A digital camera as claimed in claim 2, further comprising an
indicator for indicating a warning when electronic zoom is performed.
4. A digital camera as claimed in claim 3, wherein said indicator
is provided at a position that is viewable when the photographer
is looking in said optical finder.
5. A digital camera as claimed in claim 3, further comprising a
zooming lens for image sensing, and said indicator indicates the
warning when an effective magnification of one or both an optical
zoom of said zoom lens or said electronic zoom exceeds a magnification
range of said optical finder.
6. A digital camera as claimed in claim 1, wherein said controller
maintains the state of said electronic finder even when said effective
magnification is changed to more than a minimum and less than a
maximum possible the magnification of the optical finder.
7. A digital camera comprising: an optical finder for optically
viewing a photographic object; an electronic finder for electronically
displaying a photographic object; an operation member for performing
an electronic zoom; a switching member for switching between an
activated state and a deactivated state of the electronic finder;
a setter for setting a magnification for image sensing when the
digital camera is activated; and a controller for setting said electronic
finder to the activated state when said magnification is determined
to be outside a magnification range of the optical finder, wherein
said magnification range extends from a minimum to a maximum magnification
of said optical finder.
8. A digital camera as claimed in claim 7, further comprising a
memory for storing a magnification for image sensing when the digital
camera power source is turned OFF, and said setter is set to the
magnification stored in the memory.
9. A digital camera comprising: an optical finder for optically
viewing a photographic object; an electronic finder for electronically
displaying a photographic object; an operation member for performing
an electronic zoom; a setter for setting a magnification for image
sensing when the digital camera is activated; and an indicator for
indicating a warning when said magnification is outside a magnification
range of the optical finder, wherein said magnification range extends
from a minimum to a maximum possible magnification of said optical
finder.
10. A digital camera as claimed in claim 9, further comprising
a memory for storing a magnification for image sensing when the
digital camera power source is turned OFF, and said setter is set
to the magnification stored in the memory.
11. A recording medium contains a program to be executed by a digital
camera having an optical finder for optically viewing a photographic
object, an electronic finder for electronically displaying a photographic
object, an operation member for performing an electronic zoom, and
a switching member for switching the electronic finder between an
activated state and a deactivated state, said program implementing:
performing the electronic zoom by said operation member; and setting
said electronic finder to the activated state forcedly when an effective
magnification of one or both an optical zoom and an electronic zoom
is less than a minimum or more than a maximum possible magnification
of said optical finder, even if the electronic view finder had been
manually turned off. Digital Camera Patent DescriptionThis application is based on Patent Application No. 11-354565 filed
in Japan, the content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a digital camera provided with
a zoomable optical finder and electronic finder having an electronic
zoom function. The present invention further relates to a recording
medium for recording programs readable by the digital camera.
2. Description of the Related Art
Most digital cameras have a finder for electrically displaying
an image via liquid crystal device (LCD) or the like (hereinafter
referred to as "electronic finder"). However, in such
digital cameras, the electronic finder juxtaposed with an optical
finder is optionally turned ON/OFF via a switch in order to prevent
battery power consumption.
Digital cameras are known which are provided with a electronic
zoom function of about 2.times. without deterioration of image quality
in order to enlarge a photographic object while maintaining the
compactness of the camera. Since the field of view of the optical
finder does not match the actual photographic range during electronic
zooming, a field of view frame is displayed in the optical finder
during electronic zooming.
Although it is possible to associate the field of view of the optical
finder with the actual photographic range in this way, a disadvantage
arises in that it is difficult to confirm a photographic subject
simply by displaying the photographic range with a simple field
of view frame because the subject cannot be optically displayed
in enlargement.
Japanese Laid-Open Patent Application No. H6-189173 discloses a
digital camera wherein a finder optical system zooms in response
to electronic zooming. This application discloses a digital camera
provided with an actual zoom function of up to 6.times. by using
together a 3.times. optical zoom and a 2.times. electronic zoom,
thereby having an optical finder with a 6.times. zoom ratio corresponding
to the combined 6.times. zoom ratio.
According to this art, however, although the photographic subject
is easily confirmed and framing is easily accomplished, the optical
finder is provided a zoom function corresponding to the effective
zoom function. Accordingly, the optical finder is larger and heavier,
and disadvantageously interferes with the compactness of the camera.
An object of the present invention is to eliminate the disadvantages
of the conventional art by providing a digital camera and recording
medium allowing easy confirmation of a photographic object and easy
framing without interfering with the compactness of the digital
camera.
SUMMARY OF THE INVENTION
These objects are attained by the digital camera of the present
invention comprising: an optical finder for optically viewing a
photographic object; an electronic finder for electronically displaying
a photographic object; an operation member for performing an electronic
zoom; a switching member for switching between an activated state
and a deactivated state of the electronic finder; and a controller
for setting the electronic finder to the activated state forcedly
when the electronic zoom is performed by the operation member.
These objects are further attained by another digital camera of
the present invention comprising: an optical finder for optically
viewing a photographic object; an electronic finder for electronically
displaying a photographic object; an operation member for performing
an electronic zoom; a switching member for switching between an
activated state and a deactivated state of the electronic finder;
a zooming lens for image sensing; and a controller for setting the
electronic finder to the activated state forcedly when an effective
magnification of one or both an optical zoom of said zoom lens or
said electronic zoom exceeds a magnification range of said optical
finder.
These objects are further attained by another digital camera of
the present invention comprising: an optical finder for optically
viewing a photographic object; an electronic finder for electronically
displaying a photographic object; an operation member for performing
an electronic zoom; a switching member for switching between an
activated state and a deactivated state of the electronic finder;
a setter for setting a magnification for image sensing when the
digital camera is activated; and a controller for setting said electronic
finder to the activated state when said magnification is determined
to be outside a magnification range of the optical finder.
These objects are further attained by another digital camera of
the present invention comprising: an optical finder for optically
viewing a photographic object; an electronic finder for electronically
displaying a photographic object; an operation member for performing
an electronic zoom; a setter for setting a magnification for image
sensing when the digital camera is activated; and an indicator for
indicating a warning when said magnification is outside a magnification
range of the optical finder.
These objects are further attained by A recording medium in which
a program to be executed by the digital camera having an optical
finder for optically viewing a photographic object, an electronic
finder for electronically displaying a photographic object, an operation
member for performing an electronic zoom, and a switching member
for switching between an activated state and a deactivated state
of the electronic finder is recorded and which can be read by a
computer, said program implementing: performing the electronic zoom
by said operation member; and setting said electronic finder to
the activated state forcedly when the electronic zoom is performed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following description, like parts are designated by like
reference numbers throughout the several drawings.
FIG. 1 is a front view of a digital camera of an embodiment of
the present invention;
FIG. 2 is a back view of a digital camera of an embodiment of the
present invention;
FIG. 3 is a side view of a digital camera of an embodiment of the
present invention;
FIG. 4 is a bottom view of a digital camera of an embodiment of
the present invention;
FIG. 5 is a block diagram showing the internal structure of the
digital camera of an embodiment of the present invention;
FIGS. 6(a) and 6(b) show the internal structure of the optical
finder;
FIG. 7 is a block diagram showing the structure of the image processor;
FIG. 8 shows the condition of the electronic zoom process;
FIG. 9 is a flow chart showing the processing sequence from power
ON to power OFF;
FIG. 10 is a flow chart showing the initialization process sequence;
FIG. 11 is a flow chart showing the zoom process sequence during
the photography standby;
FIG. 12 is a flow chart showing the process of LCD automatic display
control;
FIG. 13 is a flow chart showing the LCD ON/OFF control process
sequence;
FIG. 14 is a flow chart showing the warning LED control process
sequence; and
FIG. 15 shows a modification of the warning means.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention are described
hereinafter with reference to the accompanying drawings.
FIGS. 1 through 4 respectively show a front view, back view, side
view, and bottom view of a digital camera 1 of an embodiment of
the present invention. FIG. 5 is a block diagram showing the internal
structure of the digital camera 1.
The digital camera 1 comprises a box-like camera body 2, and a
rectangular image sensing unit 3 (indicated by the thick lines in
FIGS. 1, 2, and 4) as shown in FIG. 1. The image sensing unit 3
has a macro function zoom lens 301 acting as a taking lens, and
is provided with an image sensing circuit 302 having a CCD 303 (refer
to FIG. 5) acting as a 1/2 inch size CCD color area sensor disposed
at a suitable position behind the zoom lens 301. The zoom lens 301
has a focal length of 7 mm in the wide state and 21 mm in the telecentric
state, and has a zoom ratio of 3.times.. The digital camera 1 is
capable of a maximum 6.times. zoom photography via an electronic
zoom function described later.
A light adjusting control circuit 304 having a light adjusting
control sensor 305 for receiving the reflected light of the flash
from the photographic object is provided at a suitable location
within the image sensing unit 3 similar to a camera using silver
halide film. In addition, a distance measuring sensor 306 for measuring
the distance to a photographic object and an optical finder 31 are
provided at suitable locations within the image sensing unit 3.
The internal structure of the optical finder 31 is described later.
On the front surface of the camera body 2 is provided a grip 4
on the left end and a built-in flash 5 on the top center, and a
shutter button 8 is provided on the top surface, as shown in FIG.
1.
On the back surface of the camera body 2 is provided an LCD 10
as a photographic image monitor display (equivalent to a viewfinder),
and for displaying the recorded images at the approximate center
of the back surface as shown in FIG. 2. The LCD 10 is equivalent
to an electronic viewfinder. Below the LCD 10 are provided key switches
221.about.226 for operating the digital camera 1, and a power switch
227. On the left side of the power switch 227 are arranged an LED
228 which lights when the power is ON, and an LED 229 which displays
while a memory card is being accessed.
Also on the back surface of the camera body 2 is a mode setting
switch 14 for selecting among [photographic mode], [reproduction
mode], and [preference mode] (refer to FIG. 2). The photographic
mode is used for taking photographs. The reproduction mode is a
mode for reproducing a photographed image recorded on a memory card
and displaying the image on the LCD 10. The preference mode is a
mode for settings of various types by selecting a desired item from
among display items (setting items). The operations in each mode
are described later.
The mode setting switch 14 is a contact point slide switch and
sets the photographic mode when at the bottom, sets the reproduction
mode at the center, and sets the preference mode at the top, as
shown in FIG. 2.
A 4-point switch 230 is provided on the right side of the back
surface of the camera. In the photographic mode, a zoom motor 307
(refer to FIG. 5) drives the zoom lens 301 for zooming by pressing
the buttons 231 and 232. The zoom lens 301 is driven to the wide
side when button 231 is pressed, and driven to the telecentric side
when the button 232 is pressed.
On the back of the image sensing unit 3 are provided an LCD button
321 for turning ON and OFF the LCD 10, and a macro button 322. When
the LCD button 321 is pressed, the LCD display is switched ON or
OFF. For example, during photography using only the optical finder
31, the LCD display is switched OFF to conserve power. When the
macro button 322 is pressed during macro photography, an AF motor
308 (refer to FIG. 5) is driven to place the zoom lens 301 in the
macro photography enabled state.
On the side of the camera body 2 is provided a pin unit 235, as
shown in FIG. 3. The pin unit 235 is provided with a DC input pin
235a, and a video-out pin 235b for outputting the content displayed
on the LCD 10 to an external video monitor.
On the bottom surface of the camera body 2 are provided a battery
compartment 18 for loading a battery, and a card compartment 17,
as shown in FIG. 4. The card compartment 17 has a slot-shaped insertion
opening used for inserting a memory card 91 within the camera body
2 to allow writing and reading of image data to/from the memory
card 91. Both compartments can be opened and closed using a clam-shell
type door. FIG. 4 shows an example with a memory card 91 installed
in the card compartment 17.
In the digital camera 1, four AA-size dry cell batteries are installed
in the battery compartment 18, and connected in series as to form
the power source battery 236 (refer to FIG. 5) which is used as
the drive source. Of course, electric power also may be supplied
from an adapter using the DC input pin 235a shown in FIG. 4.
The bottom surface is also provided with release lever 19 for releasing
the connection between the image sensing unit 3 and the camera body
2 which are connected by a connector and key-like connecting member.
The internal structure of the image sensing unit 3 is described
below with reference to FIG. 5.
The image sensing circuit 302 photoelectrically converts an optical
image of the photographic object formed on the CCD 303 by the zoom
lens 301 using the CCD 303, and outputs the image as red (R), green
(G), blue (B) color component image signals (signals comprising
a signal series of pixel signals of the light received by each pixel).
Since the diaphragm is fixed in the digital camera 1, exposure
control in the image sensing unit 3 is accomplished by regulating
the amount of exposure light of the CCD 303 (i.e., the load accumulation
time of the CCD 303 corresponding to shutter speed). When a suitable
shutter speed cannot be set when the photographic object luminance
is a low luminance, unsuitable exposure due to insufficient exposure
light can be corrected by adjusting the level of the image signal
output from the CCD 303. That is, during times of low luminance,
exposure can be controlled by combining shutter speed and gain adjustment.
The image signal level adjustment is accomplished by the auto gain
control circuit (AGC) within a signal processing circuit 313 described
later.
A timing generator 314 generates a drive control signal for the
CCD 303 based on a clock signal transmitted from a timing control
circuit 202 within the camera body 2. The timing generator 314 generates
clock signals, for example, such as a storage start/end timing signal
(i.e., exposure start/end), read control signal (horizontal synchronization
signal, vertical synchronization signal, transfer signal and the
like) of each pixel photoreception signal and the like, and outputs
these signals to the CCD 303.
The signal processing circuit 313 performs specific analog signal
processing of image signals (analog signals) output from the image
sensing circuit 302. The signal processing circuit 313 includes
a correlation double sampling (CDS) circuit and an auto gain control
(AGC) circuit, and reduces the noise of the image signals via the
CDS circuit, and adjusts the level of the image signals by adjusting
the gain via the AGC circuit.
The light adjusting control circuit 304 controls the amount of
light emitted by the built-in flash 5 during flash photography to
the specific amount of light emission set by the general controller
211 of the camera body 2. When the amount of received light attains
the specific amount of emission light, a flash stop signal is output
from the light adjusting control circuit 304 to the flash control
circuit 214 via the general controller 211. The flash control circuit
214 forcibly stops light emission by the built-in flash 5 in response
to the emission stop signal, and in this way the amount of light
emitted from the flash 5 is controlled to the specific emission
amount.
Within the image sensing unit 3 are provided a zoom motor 307 for
moving the lens between a housed position and photography position
and for changing the zoom ratio of the zoom lens 301, and an autofocus
(AF) motor 308 for focus adjustment, and a finder motor 311 for
moving the lens to change the zoom ratio of the optical finder.
FIGS. 6(a) and 6(b) show the internal structure of the optical
finder 31; FIG. 6(a) shows the telecentric state, and FIG. 6(b)
shows the wide state. The optical finder 31 is provided with a finder
zoom lens comprising objective lens 310a, lens 310b and an eyepiece
lens 310c as a finder optical system, and the magnification is changed
by moving the lens 310b in the optical axis direction via the drive
of the finder motor 311. The magnification of the finder zoom lens
310 is limited, and in the present embodiment the obtainable magnification
is between 1.0.about.3.0.
A warning LED 312 is provided within the optical finder 31 which
warns by lighting with a specific timing described later. A photographer
looking through the optical finder 31 easily becomes aware of the
switch from the optical finder to the electronic finder by seeing
the lighted warning LED 312.
Referring back to FIG. 5, the internal structure of the camera
body 2 is described below.
The general controller 211 mainly comprises a CPU, and controls
each peripheral structure of the camera body 2 and the interior
of the image sensing unit 3 connected by address bus, data bus,
and control bus, and performs general control of photographic operations
of the digital camera 1.
The flow of the image data in FIG. 5 (and FIG. 7 described later)
is indicated by arrows between the peripheral structures, but actually
the image data are transmitted to each peripheral structure through
the general controller 211. For this reason within the general controller
211 are provided a DRAM work RAM M211a, a flash ROM 211b for storing
control programs, previous magnification when the power is OFF and
previous condition of the LCD when the power is OFF, and an expansion
processor 211c for a thinness process and interpolation process
described later.
Image signal processing within the camera body 2 and structures
relating to image display are described below.
Analog image signals transmitted from the signal processing circuit
312 of the image sensing unit 3 are subjected to various image processing
in the image processor 200 within the camera body 2. FIG. 7 is a
block diagram showing the structure of the image processor 200.
First, the analog image signal transmitted to the image processor
200 is converted to a 10-bit digital signal for each pixel in the
A/D converter 205. The A/D converter 205 converts each pixel signal
(analog signal) to a 10-bit digital signal based on the clock signal
of the A/D converter input from the timing control circuit 202.
The timing control circuit 202 generates a standard clock signal,
and clock signals for the timing generator 314 and A/D converter
205 via control by the general controller 211.
A black level correction circuit 206 corrects the black level the
A/D converted pixel signal (hereinafter referred to as "pixel
data") to a standard black level. A WB circuit 207 performs
level conversion of the pixel data of each color component R, G,
B, and adjusts the white balance in consideration of gamma correction
in a later process. The white balance adjustment is accomplished
using a level conversion table (properly speaking, the data of the
table) input from the general controller 211 to the WB circuit,
and the conversion coefficient (characteristics slope) of each color
component of the level conversion table is set for each photographic
image by the general controller 211.
A gamma correction circuit 208 corrects the gamma characteristic
of the pixel data. The output from the gamma correction circuit
208 is transmitted to an image memory 209 as shown in FIG. 5.
The image memory 209 is a memory for storing pixel data output
from the image processor 200, and has a 1-frame memory capacity.
That is, the image memory 209 has a memory capacity sufficient to
store pixel data of n.times.m pixels when the CCD 303 has pixels
arrayed in a matrix of n lines and m columns (where n and m are
natural numbers), and stores the pixel data in a corresponding memory
area (address).
A VRAM 210 is a buffer memory for image data reproduced and displayed
on the LCD 10. The VRAM 210 has a memory capacity sufficient to
store image data corresponding to the number of pixels of the LCD
10.
According to this construction, in the photography standby state
in the photographic mode, pixel data of an image sensed at specific
intervals by the image sensing unit 3 are processed by the image
processor 200, and stored in the image memory 209. The image data
are subjected to a thinness process described later in accordance
with the magnification set by pressing the buttons 231 and 232 (hereinafter
referred to as "set magnification"), and thereafter transferred
to the VRAM 210, and displayed on the LCD 10 (live view display).
In this way the photographer is able to visually confirm an object
image via the image displayed on the LCD 10.
In the reproduction mode, after the image read from the memory
card has been subjected to specific signal processing by the general
controller 211, the data are transmitted to the VRAM 210 and reproduced
and displayed on the LCD 10. When an image is displayed on the LCD
10, a backlight 16 is lighted via control by the general controller
211.
Another structure within the camera body 2 is described below.
A card I/F 212 is an interface for bi-directional communication
with various types of memory cards installed in the card compartment
17. Specifically, writing image data to the memory card, and reading
image data from the memory card.
A flash control circuit 214 is a circuit for controlling the emission
of the built-in flash 5. The flash control circuit 214 controls
the emission or lack thereof, emission amount, and emission timing
of the built-in flash 5 based on control signals from the general
controller 211, and controls the amount of emission of the built-in
flash 5 based on an emission stop signal input from the light adjusting
control circuit 304.
A clock circuit 219 manages the photograph date and time, and is
driven by a separate battery not shown in the drawings.
Within the camera body 2 are provided a zoom motor drive circuit
215 and AF motor drive circuit 216 for driving the zoom motor 307
and the AF motor 308. These circuits function by the operation of
an operating portion 250 of a shutter button 8 and various other
types of switches and buttons described later.
For example, the shutter button 8 is a two-stage switch capable
of detecting the half-depression state, and full-depression state
used by cameras using silver halide film (hereinafter referred to
as "silver halide camera"). When the shutter button 8
is depressed half way in the photography standby state, distance
information from the distance measuring sensor 306 is input to the
general controller 211. Then, the AF motor drive circuit 216 drives
the AF motor 308 by instructions from the general controller 211,
so as to move the zoom lens 301 to the focus position.
When buttons 231 and 232 are pressed, signals from these buttons
are transmitted to the general controller 211, and the general controller
211 specifies the set magnification obtained from the signal. The
zoom motor drive circuit 215 drives the zoom motor 307 by means
of the aforesaid instruction, so as to move the zoom lens and accomplish
zooming. Then, the electronic zoom process described later is executed
by the expansion processor 211c. In this way the effective magnification
matches the set magnification, with the effective magnification
being the actual magnification during live view or photography.
Although the various structures within the camera body 2 have been
described above, the general controller 211 accomplishes various
other functions such as timing control and transfer of data with
peripheral structures through software.
For example, the general controller 211 is provided with a luminance
determination function for setting an exposure control value (shutter
speed), and a shutter speed setting function. The luminance determination
function determines the brightness of a photographic object using
the image stored in the image memory 209 and captured every 1/30.sup.th
second by the CCD 303 in the photography standby state. The shutter
speed setting function sets the shutter speed (accumulation time
of the CCD 303) based on the object brightness determination result
of the luminance determination.
The general controller 211 is provided with a filtering process
function, recorded image generation function, and reproduction image
generation function to accomplish the photographic image recording
process.
The filtering process function corrects the high frequency component
of the image being recorded via a digital filter to correct image
quality relating to contour.
The recording image generation function reads the pixel data from
the image memory 209, and generates a thumbnail image and compressed
image to be recorded on the memory card. Specifically, pixel data
are read for each 8 pixels in both horizontal and vertical directions
while scanning from the image memory 209 in the raster scan direction.
Next, a thumbnail image is generated and transferred to the memory
card and recorded on the memory card. When recording the compressed
image data on the memory card, all pixel data are read from the
image memory 209, subjected a specific compression processing by
a JPEG method such as Hoffman coding or two-dimensional DCT conversion,
and recorded on the memory card.
The specific operation is described below. When a photograph is
specified by the shutter button 8 in the photography mode, a thumbnail
image of the image in the image memory 209 is generated, and a compressed
image compressed by a JPEG method is generated based on the set
compression ratio, and both images together with tag information
relating to the photographed image (information such as frame number,
exposure value, shutter speed, compression ratio, date, time, flash
ON/OFF data, scene information, image determination result and the
like) are recorded on the memory card.
The reproduction image generation function generates a reproduced
image by expanding the compressed image recorded on the memory card.
The specific operation is described below. When the mode setting
switch 14 sets the reproduction mode, the image data of the highest
frame number in the memory card are read and expanded, and transferred
to the VRAM 210. In this way the image of the highest frame number,
i.e., the latest photographed image, is displayed on the LCD 10.
As shown in FIG. 5, when the memory card 91 is loaded in the card
compartment 17 and processing described later is executed, the general
controller 211 performs controls of the various parts described
later, and normally, the control programs are installed in the flash
ROM within the general controller 211. However, other control programs
and update programs for updating the control programs may be recorded
on a recording medium such as the set-up memory card 92 which is
loaded in the card compartment 17, such that the control programs
and update programs can be read and installed from the set-up memory
card 92.
The various processes of the digital imaging device of the present
invention are described below.
FIG. 8 shows the condition of the electronic zoom process. In the
digital camera 1 of the present embodiment, when the set magnification
is greater than a specific magnification, specifically, when the
set magnification is greater than the upper limit magnification
(zoom ratio) 3.0.times. of the zoom lens 301, the optical zoom of
3.0.times. of the zoom lens is used together with the electronic
zoom. The electronic zoom process is described below.
First, the thinness process is described which is an electronic
zoom process in live view. As shown in FIG. 8, in 2.times. zooming,
for example, a 1/2 thinness process is performed on image data of
an area of 800.times.600 pixels in the center area among the 1600.times.1200
pixel image data within the image memory 209, to derive image data
of 400.times.300 pixels, which are stored in the VRAM 210. In this
way the image data of 400.times.300 pixels stored in the VRAM 210
are displayed on the LCD 10.
Similarly, during electronic zooming in live view, an Int(x/4)
thinness process is performed on image data of region CA of Int(1600/x)xInt(1200/x)
in the center area of the image data ID1 of 1600.times.1200 pixels
(in the present embodiment, x is a number equal to or greater than
1 but less than 2, in steps of 0.1 as one step), to derive image
data ID2 of 400.times.300 pixels which are stored in the VRAM 210
and displayed on the LCD 10. Int(a) is a function representing the
area of integer a.
In the electronic zoom during live view, only image data of area
CA corresponding to the set magnification are read in the center
of the image data in the image memory 209, culled according to the
number of pixels of the LCD 10, and displayed.
The electronic zoom process during photography is described below.
When photographing at 2.times. electronic zoom, a 2.times. linear
interpolation process is performed on the image data of area CA
of 800.times.600 pixels in the center area of the image data ID1
of 1600.times.1200 pixels in the image memory 209, and the data
are stored in again in image memory 209 as 1600.times.1200 pixel
image data ID3, and thereafter subjected to the previously mentioned
compression process and the like and recorded on the memory card.
Similarly, when using X-magnification electronic zooming during
photography, an X-magnification linear interpolation process is
performed on image data within the Int(1600/x)xInt(1200/x) in the
center area of the image data of 1600.times.1200 pixels, and the
data are again stored in image memory 209 as 1600.times.1200 pixel
image data, then subjected to the previously mentioned compression
process and the like and recorded on the memory card.
In this way in electronic zooming during photography, only the
image data of area CA corresponding to the set magnification are
read from the center of the image data in the image memory 209,
interpolation is performed to obtain image data identical to the
original number of pixels, and again stored in image memory 209,
and after the previously described processing, the data are recorded
on the memory card.
The thinness process and interpolation process are accomplished
by the expansion processor 211c of the general controller 211 using
the work RAM 211a of the general controller 211 and the image memory
209.
Processes performed from the switching ON of power to the switching
OFF of power in the digital camera of the present embodiment are
described below.
FIG. 9 is a flow chart showing the sequence of processing after
power is turned ON until power is turned OFF in the digital camera
1 of the present embodiment. The first process is the initialization
process. (step S1).
FIG. 10 is a flow chart showing the sequence of the initialization
process. In the initialization process, first, other initialization
processes are executed (step S101). Specifically, the work RAM 211a,
VRAM 210, and image memory 209 are initialized. Then, when the set
magnification at the previous power OFF is greater than 3.0.times.,
the LCD 10 is forcibly turned ON because the electronic zoom is
used. Furthermore, the warning LED 312 is lighted when the electronic
zoom is used in the warning LED control of the main routine. The
set magnification when the power was previously turned OFF is the
effective magnification at the previous power OFF.
Next, the set magnification (effective magnification) at the previous
power OFF recorded in the flash ROM 211b is read (step S102). That
is, in the present embodiment, the set magnification at actuation
is identical to the set magnification at the previous power OFF,
and for this reason the set magnification at the previous power
OFF recorded in the flash ROM 211b when the camera was last used
(i.e., the process of step S7 described later) is read out from
memory.
Then, a determination is made as to whether or not the set magnification
of the previous power OFF is greater than 3.0.times. (step S103),
and if the set magnification is greater than 3.0.times., the routine
advances to step S104, whereas when the set magnification is not
greater than 3.0.times., the routine advances to step S108.
The following process is executed when the set magnification at
the previous power OFF is greater than 3,0.times..
First, the read set magnification of the previous power OFF is
set, and electronic zooming is executed in accordance with the set
magnification (step S104). That is, electronic zooming is performed
at a magnification of the set magnification divided by 3.0.
Then the zoom lens 301 is moved to the 3.0.times. position by the
drive of the zoom motor 307 (step S105). That is, the effective
magnification of both the optical zoom and electronic zoom are set
to equal the set magnification (greater than 3.0.times.).
Then, the finder zoom lens 310 is moved to the 3.0.times. position
by the drive of the finder motor 311 (step S106). Then, the LCD
10 is turned ON (step S107). In this way the LCD 10 displays image
data subjected to the previously described thinness process. The
process ends when the set magnification greater than 3.0.times.
has been set.
The process when the set magnification of the previous power OFF
is less than 3.0.times. is determined in step S103 is described
below.
First, the zoom lens 301 is moved to the position corresponding
to the set magnification by the drive of the zoom motor 307 (step
S108). Then, the finder zoom lens 310 is moved to the position corresponding
to the set magnification by the drive of the finder motor 311 (step
S109). The effective magnification is then equal to the set magnification.
Next, the ON/OFF state of the LCD 10 recorded in the flash ROM
211b at the previous power OFF is read (step S110).
Then, a determination is made as to whether or not the LCD 10 was
OFF at the previous power OFF (step S112). When the LCD 10 was ON,
the routine advances to step S107, and the LCD 10 is turned ON.
Conversely, when the LCD 10 was OFF, the initialization process
ends.
Referring to FIG. 9, the zoom process for photography standby (live
view) is executed (step S2). In step S2, when the button 231 is
pressed, the zoom magnification is decreased one step, and when
the button 232 is pressed, the zoom magnification is increased one
step. Electronic zoom is used when the set magnification is greater
than 3.0.times..
The zoom process during photography standby is described below.
FIG. 11 is a flow chart showing the sequence of the zoom process
during photography standby.
First, a determination is made as to whether or not button 232
has been pressed (step S201); if the button 232 has been pressed,
the routine advances to step S202, whereas if the button 232 has
not been pressed, the routine advances to step S208.
The process when button 232 has been pressed is described below.
First, a determination is made as to whether or not the current
set magnification is 6.0.times. (step S202). If the set magnification
is 6.0.times., the zoom process for photography standby ends because
the effective magnification cannot be increased. When the current
set magnification is not 6.0.times., the routine advances to step
S203.
When the set magnification is not 6.0.times., the set magnification
is increased one step (step S203).
Then, a determination is made as to whether or not the set magnification
is greater than 3.0.times. (step S204). If the set magnification
is greater than 3.0.times., the routine advances to step S205, whereas
when the set magnification is not greater than 3.0.times., the routine
advances to step S207.
When the set magnification is greater than 3.0.times., the original
image is subjected to thinness process based on the set magnification
(step S205).
Then, the LCD automatic display process is executed (step S206).
For example, when the set magnification is 2.8.times. and the button
232 is pressed once, the optical zoom is increased to 2.9.times.,
and when pressed once more, the optical zoom is increased to 3.0.times..
Since the limit of the optical zoom is exceeded when the button
232 is pressed once more, both 3.0.times. optical zoom and electronic
zoom controls are executed. If the LCD 10 display is OFF at this
time, the LCD 10 is turned ON in addition to the warning. This process
is the LCD automatic display control process. Details of the process
sequence are described below.
FIG. 12 is a flow chart showing the process of the LCD automatic
display control. In the LCD automatic display control process, it
is necessary to start the LCD display with a set magnification of
3.1.times., and, therefore a determination is made as to whether
or not the set magnification is 3.1.times. (step S2061). When the
set magnification is not 3.1.times., the LCD automatic display control
process ends, whereas when the set magnification is 3.1.times.,
the routine advances to step S2062.
When the set magnification is 3.1.times., a determination is made
as to whether or not the LCD 10 is turned OFF (step S2062). If the
LCD 10 is ON, the LCD automatic display control process ends, whereas
when the LCD 10 is OFF, the routine advances to step S2063, and
the LCD 10 is turned ON for display (step S2063).
The LCD automatic display control process ends, and the process
ends when the set magnification is determined to be greater than
3.0.times. in the determination of step S204 of FIG. 11.
Conversely, when the determination of step S204 is that the set
magnification is equal to or less than 3.0.times., the zoom motor
307 is driven one step to move the zoom lens 301 to the telecentric
side (step S207), and the process of the photography standby ends.
The process when the determination of step S204 is that the button
232 has not been pressed is described below.
First, a determination is made as to whether or not the button
231 has been pressed (step S208). If the button 231 has not been
pressed, there is not change to the set magnification, and the process
of photography standby ends, whereas when button 231 has been pressed,
the routine advances to step S209.
When the button 231 has been pressed, a determination is made as
to whether or not the current set magnification is 1.0.times. (step
S209). When the current set magnification is 1.0.times., the process
of photography standby ends because a lesser magnification is impossible.
When the current magnification is not 1.0.times., the routine advances
to step S210.
When the current set magnification is not 1.0.times., the set magnification
is decreased 1 step (step S210).
Then, a determination is made as to whether or not the set magnification
is greater than 3.0.times. (step S211). When the set magnification
is greater than 3.0.times., the routine advances to step S212, whereas
when the set magnification is not greater than 3.0.times., the routine
advances to step S231.
When the set magnification is greater than 3.0.times., the original
image is subjected to the thinness process based on the set magnification
(step S212).
Conversely, when the set magnification is equal to or less than
3.0.times., the zoom motor 307 is driven one step to move the zoom
lens 301 to the wide side (step S213), and the process of photography
standby ends.
Referring to FIG. 9, next, the LCD ON/OFF control process is executed
(step S3). When the set magnification is 3.1.times. or greater,
the LCD display is not always in the ON state, and a user may optionally
set the LCD display to OFF. Regardless of the magnification, the
LCD 10 ON/OFF state is switched each time the LCD button 321 is
pressed. For this reason the LCD can be positively turned OFF to
prevent battery consumption while being aware of the use of the
electronic zoom.
The sequence of the LCD ON/OFF control process is described below.
FIG. 13 is a flow chart showing the sequence of the LCD ON/OFF control
process.
First, a determination is made as to whether or not the LCD button
321 has been pressed (step S301). If the LCD button 321 has not
been pressed, the LCD ON/OFF control process ends, whereas when
button 321 has been pressed, the routine advances to step S302.
When the LCD button 321 has been pressed, a determination is made
as to whether or not the LCD 10 is turned OFF (step S302). If the
LCD 10 is OFF, the routine advances to step S303, and the LCD 10
is turned ON for display (step S303). Conversely, if the LCD 10
is ON, the LCD 10 is turned OFF (step S304), and the LCD ON/OFF
control process ends.
As can be understood from the zoom process during photography standby
of FIG. 11 and the LCD ON/OFF control process described above, the
LCD display ON/OFF state does not change even when the button 231
is pressed, and conversely changing from the telecentric side to
the wide side, and the magnification is reduced sequentially step-by-step
from 6.0.times. and from 3.1.times. to 3.0.times.. This arrangement
is due to the strong unease when the LCD is suddenly turned OFF
and mistaken belief of a power outage when framing a photo with
the LCD 10 , which adversely affects operability. In the digital
camera 1 of the present embodiment, such events are prevented.
Referring to FIG. 9, the warning LED control process is then executed
(step S4). During electronic zoom, since the confirmable range by
the optical finder does not match the actual photographic range,
the warning LED 312 is always lighted when the set magnification
is 3.1 or greater. The power consumption of the LED is not a problem
even when always lighted because the power consumption is very slight
compared to the LCD 10.
Details of the process sequence of the warning LED control process
are described below. FIG. 14 is a flow chart showing the sequence
of the warning LED control process.
First, a determination is made as to whether or not the set magnification
is 3.1.times. or greater (step S401). If the set magnification is
3.1.times. or greater, the routine advances to S402, whereas when
the set magnification is not 3.1.times. or greater, the routine
advances to step S404.
When the set magnification is 3.1 or greater, a determination is
made as to whether or not the warning LED 312 is OFF (step S402).
If the warning LED 312 is ON, the warning LED control process ends,
whereas when the warning LED 312 is OFF, it is turned ON (step S403),
and the warning LED control process ends.
Similarly, even when the set magnification is less than 3.1.times.,
a determination is made as to whether or not the warning LED 312
is OFF (step S404). If the warning LED 312 is OFF, the warning LED
control process ends, whereas when the warning LED 312 is ON, the
warning LED 312 is turned OFF (step S405), and the warning LED control
process ends.
Referring to FIG. 9, then other processes are executed (step S5).
This process is the basic process of the digital camera, and is
a process of the photographic mode in which the auto exposure (AE)
and autofocus (AF) are performed are by half pressing the shutter
button 8. When the shutter button 8 is fully pressed, if necessary
flash emission is performed, and image data (i.e., data subjected
to the electronic zoom interpolation process) are compressed and
recorded on the memory card. The process in the photographic mode
is also executed in step S5.
Next, a determination is made as to whether or not the power switch
227 has been pressed (step S6). If the power switch has not been
pressed, the routine returns to step S2, and until the power switch
227 has been pressed, the processes of steps S2.about.S5 are repeated.
Then, when the power switch 227 is pressed, the routine advances
to step S7.
When the power switch S7 is pressed, the current set magnification
(effective magnification) is written to the flash ROM 211b, and
the state of the LCD 10 display (ON/OFF) is written to the flash
ROM 211b for use at subsequent start (step S7).
Finally, the power OFF process to turn OFF the power supply is
executed (step S8).
This ends the description of the processes performed in the digital
camera of the present embodiment.
According to the present embodiment as described above, during
electronic zooming by pixel thinness or pixel interpolation by an
expansion processor 211c used as an electronic zoom means, the LCD
10 is forcibly turned ON as an electronic finder regardless of the
previous state. Therefore, since the LCD 10 has a zoom function
corresponding to the effective magnification including the electronic
zoom by the processing by the expansion processor 211c, the image
of the photographic object corresponding to the effective sensing
magnification during electronic zooming can be confirmed on the
LCD 10 even when the optical finder 31 does not possess this zoom
function. Accordingly, The compactness of the digital camera is
not hindered, the photographic object is easily confirmed, and framing
is simple. Furthermore, The electrical power of the digital camera
can be conserved by switching OFF the LCD 10 when electronic zoom
is not used.
Since the warning LED 312 is lighted and the LCD 10 is turned ON
when using the electronic zoom, the photographer is easily aware
when electronic zoom is used.
Furthermore, when the effective magnification of the joint operation
of the zoom lens 301 as an optical zoom means and the expansion
processor 211c as an electronic zoom means is outside the magnification
range obtainable by the optical finder 31 (specifically, when the
effective magnification is greater than 3.0.times.), the warning
LED 31 is lighted and the image is displayed on the LCD 10, such
that the mismatch of the photographic range and the field of view
of the optical finder 31 can be shown when using the optical finder
31.
Similarly, when the effective magnification of the joint operation
of the zoom lens 301 and the expansion processor 211c is outside
the magnification range obtainable by the optical finder 31 (specifically,
when the effective magnification is greater than 3.0.times.), the
LCD 10 is forcibly turned ON regardless of its previous state. In
this way the mismatch of the photographic range and the field of
view of the optical finder 31 can be shown by referencing the LCD
10 when using the optical finder 31.
Since the LCD 10 is forcibly turned ON when the starting magnification
exceeds the range obtainable by the optical finder 31 when the digital
camera is started, i.e., when the effective magnification is determined
to be greater than 3.0.times., the photographer can be alerted to
the mismatch between the photographic range and the field of view
of the optical finder 31 when the starting magnification exceeds
the magnification obtainable by the optical finder 31.
Since the power OFF magnification of the previous power shutdown
recorded in flash ROM 211b is set as the starting magnification,
the photographer need not set the magnification of the previous
power OFF because the starting magnification used is the magnification
of the previous power OFF, thereby improving operability.
Since an operation switch is provided which is capable of turning
OFF the LCD 10 when the LCD 10 is in the forced ON state, battery
power consumption can be greatly conserved by turning OFF the power-draining
LCD 10 with the full awareness of the mismatch of the photographic
range and the field of view of the optical finder 31.
Since the photographer is warned by the lighting of the LED 312
and display on the LCD 10 when the starting magnification exceeds
the magnification range obtainable by the optical finder 31, the
photographer is alerted to the mismatch of the photographic range
and the field of view of the optical finder 31.
Modifications
Although the digital camera and recording medium of the embodiments
have been described by way of examples, the present invention is
not limited to these examples.
For example, although the warning LED 312 is lighted and displayed
in the warning LED control process, the warning means may be suitably
modified. For example, a speaker may be provided to issue an audible
warning or warning sound. FIG. 15 shows a modification of the warning
means. This warning means is provided with a Porro prism 401 within
the optical system of the optical finder, a transmission type LCD
402 disposed above the Porro prism 401, and a transparent window
403 provided on the top surface of the image sensing unit 3 is disposed
above the LCD 402. External light entering the window 403 is transmitted
through the transmission type LCD 402, and arrives at the photographer
side via the Porro prism 401. Then, when the electronic zoom is
used, a warning text is displayed on the transmission type LCD 402
and alerts the photographer. In this way the photographer can confirm
the warning text overlaid on the photographic object via the optical
finder, thereby easily being made aware of the use of the electronic
finder.
The position at which the warning means is provided is also optional.
Specifically, the warning means may be disposed on the surface of
the camera body 2 insofar as it is observable while looking in the
optical finder.
In the above described embodiments, the electronic finder is turned
ON when transitioning from a state of using the optical zoom alone
to the state of using the optical zoom and electronic zoom in combination.
However, the present invention is not limited to this arrangement,
and the range of the art of the present invention further includes
which zoom only using an electronic zoom wherein the electronic
zoom is turned ON when transition from a state of no zoom to a state
of using the electronic zoom.
In the above embodiments, when the set magnification (effective
magnification) exceeds the upper limit magnification (3.0.times.)
of the optical finder, the warning LED 312 is lighted, and the LCD
10 forcibly displays in warning. However, the present invention
is not limited to this arrangement, inasmuch as the warning LED
312 may be lighted and LCD 10 forced to display in warning when
a specific lower limit different from 1.0.times. of the optical
finder is set.
Although the upper limit magnification (zoom ratio) of the zoom
lens 301 used as an optical zoom and the upper limit magnification
(zoom ratio) of the optical finder 31 are both 3.0.times. in the
above embodiments, these upper limits need not necessarily be identical.
In this case, when, for example, the optical zoom magnification
exceeds the zoom ratio of the optical finder, the warning LED 312
may be lighted and the display of the LCD 10 may be forced as an
electronic finder.
Although the optical zoom is used in electronic zooming in the
above embodiments, a mode may be provided for using electronic zoom
alone. In this case, when the electronic zoom magnification exceeds
the zoom ratio of the optical finder, the LCD 10 display may be
forced as an electronic finder. Furthermore, while the above embodiments
have been described as performing a pixel thinness process or pixel
interpolation process after trimming the center area when using
the electronic zoom, trimming may be performed alone.
Although the present invention has been fully described by way
of examples with reference to the accompanying drawings, it is to
be noted that various changes and modification will be apparent
to those skilled in the art. Therefore, unless otherwise such changes
and modifications depart from the scope of the present invention,
they should be construed as being included therein.
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