JP2003101851A - Image pickup device, image pickup method, computer readable storage medium and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To calculate correction data for each photographing frame even at the time of consecutive photographing at the time of bracket photographing and to surely and accurately synthesize images for each photographing frame. SOLUTION: In an image pickup device which generates electronic image data by photoelectrically converting an optical image of an object in an image pickup element and records the generated electronic image data in a recording medium, at the time of photographing the object, the correction data are calculated for each photographing frame even during the consecutive photographing when the bracket photographing is accompanied by a change of a gain of output signals from the image pickup element. The correction data are calculated for each photographing frame even during the consecutive photographing when the bracket photographing is accompanied by the change of the gain (ISO value or the like) of the output signals from the image pickup element every time of photographing. Thus, the images are surely and accurately synthesized for each photographing frame.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus, an image pickup method, a computer-readable storage medium, and a computer program, and more particularly to an image processing apparatus for picking up, recording, and reproducing a still image or a moving image in a digital camera or the like. , And an image processing apparatus control method.

[0002]

2. Description of the Related Art Conventionally, this type of digital still camera has a structure as shown in FIG. Figure 1 above
In the case of the digital camera shown by 7, the overall control circuit 200 detects a change in the state of the camera operation switch 201 (consisting of the main SW and the release SW of the camera) by the photographer himself, and supplies power to each of the other circuit blocks. To start.

A subject image within the range of the photographing screen is formed on the image pickup element 204 through the main photographing optical systems 202 and 203, and an electric signal from the image pickup element 204 is converted into a CDS / A.
Through the GC circuit 205, the A / D conversion unit 206 sequentially converts each pixel into a predetermined digital signal.

Here, the image pickup device 204 is driven by the output of the driver circuit 207 for horizontal driving and vertical driving for each pixel based on the signal from the timing generator 208 which determines the overall driving timing. Generate an image signal output. Similarly, the image sensor 20
4. The CDS / AGC circuit 205, which processes the output from A4 in an analog manner and converts it into a predetermined signal level, and A / A
The D conversion circuit 206 is also the timing generator 208.
It operates based on the timing from.

The output from the A / D conversion circuit 206 is sent to the memory controller 215 via a selector 209 which selects a signal based on a signal from the overall control CPU 200.
Where all signal outputs are transferred to the frame memory 216. Therefore, in this case, all the pixel data for each shooting frame is once stored in the frame memory 216, and therefore, in the case of continuous shooting and the like, all write operations to the frame memory 216 are performed.

After the shooting operation is completed, the contents of the frame memory 216 storing the shooting data are transferred to the camera DSP 210 through the selector 209 under the control of the memory controller 215. This camera DSP210
Then, RGB color signals are generated based on each pixel data of each shooting data stored in the frame memory 216.

In a state prior to normal photographing, the result is periodically (frame by frame) transferred to the video memory 211 to display a finder or the like via the monitor display means 212.

On the other hand, when the photographer performs the photographing operation by operating the camera operation switch 201, each pixel data for one frame is read from the frame memory 216 by the control signal from the overall control CPU 200, and the camera is operated. The image is processed by the DSP 210 and then temporarily stored in the work memory 213.

Subsequently, the data in the work memory 213 is compressed by the compression / expansion means 214 according to a predetermined compression format, and the result is stored in the external nonvolatile memory 217.
(Usually non-volatile memory such as flash memory is used)
Remember.

On the other hand, when observing image data that has already been photographed, the data compressed and stored in the external memory is decompressed by the compression / decompression means 214 into the data for each normal photographing pixel, and the result is obtained. By transferring to the video memory 211, it can be performed through the monitor display means 212.

As described above, in a normal digital camera,
The configuration is such that the output from the image sensor 204 is converted into actual image data through a process processing circuit in substantially real time, and the result is output to a memory or a monitor circuit.

On the other hand, in the above digital camera system, the capability of continuous shooting etc. is improved (for example,
In order to obtain a capacity close to 10 frames / sec.), It is necessary to improve the system including the image sensor such as increasing the reading speed from the image sensor and writing the image sensor data to the frame memory. Is.

FIG. 16 shows C as one of the improvement methods.
It is a simple illustration of a two-output type device structure in which a horizontal CCD is divided into two in an image pickup device such as a CD. FIG.
In this CCD, the electric charge for each pixel generated in the photodiode section 190 is simultaneously applied to the vertical CCD at a predetermined timing.
Transfer to the unit 191 and the vertical C for each line at the next timing
The charge of the CD is transferred to the horizontal CCDs 192 and 193.

Here, the horizontal CCD 192 transfers the electric charge to the amplifier 194 on the left side every transfer clock,
Further, since the horizontal CCD 193 transfers the electric charge to the amplifier 195 on the right side at each transfer clock, the image data of the CCD is divided into the left and right sides with the center of the screen as a boundary and is read out. .

Normally, the above-mentioned amplifiers are built in a CCD device, but since they are located far apart from each other in layout, the relative precisions of the two amplifiers are not always exactly the same. Therefore, when the outputs after the amplifiers are passed through the CDS / AGC circuits 196 and 198 for the left and right respectively, the matching between the left and right outputs is ensured by adjusting by the external adjusting means 197 and 199.

When a solid-state image pickup device such as a CCD is used for image pickup, dark image data read after accumulating charges in the same manner as in the main photographing without exposing the image pickup device and the image pickup device exposed. In some cases, long-time exposure is required to perform dark noise correction processing by performing arithmetic processing using the main captured image data read after the charge storage.

As a result, it is possible to correct the photographed image data and photograph a high quality image with respect to image quality deterioration such as dark current noise generated by the image pickup element and pixel loss due to minute scratches peculiar to the image pickup element.

In particular, the dark current noise increases in accordance with the charge accumulation time and the temperature rise of the image pickup device, so that it is possible to obtain a great image quality improving effect when performing exposure for a long time or exposure at a high temperature. The dark noise correction process is a useful function for users of electronic cameras.

Further, as described in Japanese Patent Application Laid-Open No. 11-4380, the electronic camera having auto-bracketing photographing can obtain a plurality of image data with different exposures from one-time photographed image data. Have been proposed.

[0020]

As described above, as an image pickup device capable of realizing high-speed reading, a method of simultaneously reading signals from two or more plural outputs is used in a future digital camera by using a silver salt camera (already a single-lens reflex camera). This is an indispensable technology in order to get closer to the type of silver-salt camera that has the specifications of about 10 frames / sec.).

However, although having a plurality of outputs is advantageous in terms of speed, it is obviously disadvantageous from the viewpoint of matching of output levels as compared with the case where there is only one output.

A simple manual adjustment method such as an analog adjustment in a conventional CDS / AGC circuit section or a digital adjustment in which both channels are matched with the output after A / D conversion is considerably performed in the manufacturing process. Even if you match
For example, the value of the VR resistance itself changes due to changes in the environment, and the tendency of the temperature characteristics of the CDS / AGC circuit to completely match the two is extremely low.

Further, the sensitivity setting of the image pickup device (IS of the camera
When the (O value) is changed, the gain change of the analog signal output from each image sensor is changed, so that the gain difference between the left and right is amplified due to the gain change width, and the two gains can completely match. The sex is extremely low.

Normally, when such a method of reading out the image pickup device is performed, if the relative accuracy of the left and right outputs exceeds ± 1%, the imbalance of the boundary is clearly understood on the screen.

When performing dark noise correction processing,
Since the main shooting is performed after shooting the dark image data, the shooting frame intervals can be made constant during normal continuous shooting, but the frame speed becomes slow.

In the auto-bracketing photography described in Japanese Patent Laid-Open No. 11-4380, 1
Since images with different exposures are created by image processing with the captured data of one time, there is a concern that the image processing deteriorates the image and the degree of freedom of the subsequent image processing decreases. In particular, for professional use, it is required to use raw data (RAW data) from an image sensor that has not been subjected to image processing that requires a degree of freedom in image processing. In JP-A-11-4380, , RAW data with different exposure cannot be obtained.

The present invention has been made in view of the above-mentioned problems. In the bracket shooting in which the gain (ISO value or the like) of the output signal from the image sensor is changed for each shooting, the shooting is performed even in the continuous shooting. A first object of the present invention is to calculate correction data for each frame so that image composition for each frame can be performed reliably and accurately.

Further, even during bracket shooting in which the gain (ISO value or the like) of the output signal from the image pickup device is changed for each shooting, the correction data calculation operation is performed for each shooting when the gain change width is small. It is a second object of the present invention to prevent high speed continuous shooting without reducing the continuous shooting frame speed.

Further, even during continuous shooting, dark current noise data is taken for each shooting when shooting at a low shutter speed that does not affect the continuous shooting frame speed, so that shot images can be corrected. Thirdly, regarding a photographed image in a long-time exposure that is largely influenced by dark current noise, it is possible to obtain a good photographed image without a feeling of noise with almost no influence on the frame speed. To aim.

[0030]

An image pickup apparatus of the present invention is an image pickup apparatus which photoelectrically converts an optical image of a subject by an image pickup element to generate electronic image data, and records the generated electronic image data on a recording medium. That is, when shooting the subject, correction data is calculated for each shooting frame even during continuous shooting during bracket shooting that involves changing the gain of the output signal from the image sensor. Is characterized by. Another feature of the present invention is an imaging device that photoelectrically converts an optical image of a subject with an imaging element to generate electronic image data, and records the generated electronic image data on a recording medium. When the subject is photographed, the correction data is calculated for each photographing frame when the gain change width is small even in the bracket photographing in which the gain of the output signal from the image sensor is changed. The feature is that it is prohibited. Another feature of the present invention is an imaging device that photoelectrically converts an optical image of a subject with an imaging element to generate electronic image data, and records the generated electronic image data in a recording medium. Even when shooting the above-mentioned subject continuously, when shooting at a low shutter speed that does not affect the continuous shooting frame speed, the dark current noise data is taken for each shooting to correct the shot image. It is characterized by having done. Another feature of the present invention is an image pickup apparatus that records a still image and / or a moving image generated by picking up an image of a subject in a recording medium, and a continuous shooting mode and a 1 A shooting mode selection unit having a frame shooting mode and capable of selectively selecting the continuous shooting mode and the single frame shooting mode, and a first shooting mode for accumulating charges without exposing the subject light. , And a second imaging mode in which the subject light is exposed to accumulate charges, and when the continuous shooting mode is set, before the second imaging mode at the start of continuous shooting or after the continuous shooting ends. The second shooting mode after the second shooting mode, the first shooting sequence in which at least one of the shooting modes is set to the first shooting mode;
Before and after the second image capturing mode, at least one of them has a second image capturing sequence for performing the first image capturing mode, and when a predetermined image capturing condition is set, the first image capturing sequence and the second image capturing sequence are set. And a photographing sequence control means for switching the photographing sequence of No. 1 to No. Another feature of the present invention is that the image pickup area is divided into a plurality of pieces, and the image pickup means capable of reading the divided image pickup data simultaneously through a plurality of outputs and the output from the image pickup means are individually provided. Is disposed in the vicinity of the image pickup means, the image pickup signal processing means for processing the image pickup signal processing means, the mutual relation judging means for judging the mutual correlation of the data in a predetermined image area with respect to the output from the image pickup signal processing means, In addition, the projection means for projecting a predetermined amount of light to the imaging means and the image irradiated by the light projected by the projection means are imaged by the imaging means, and the imaging result In the first image pickup mode in which the image pickup signal processing means processes the image signal, and a correction for correcting the output image signal of each of the image pickup signal processing circuits according to the determination result from the mutual relationship determining means. Correction data calculation means for calculating the data, correction data storage means for storing and holding the correction data calculated by the correction data calculation means, and the correction data storage means for correcting the correction data based on the correction data. It is characterized in that it is constituted by an image generating means for synthesizing output image signals captured in the two image capturing modes to generate one captured image. Another feature of the present invention is that, in the first image pickup mode, the imaged image data is dark current noise data of the image pickup means, and in the second image pickup mode, the image pickup is performed. The image data is the image data captured by the image capturing means. Another feature of the present invention is that it has bracket photographing means for photographing a plurality of frames by changing the value of at least one processing parameter information by the image processing changing means for each photographing frame, and the predetermined photographing condition is satisfied. Is characterized by bracket shooting. Another feature of the present invention is that the value of the processing parameter information is at least one of a sensitivity change, a color temperature correction, a saturation change, and a black level change. There is. Another feature of the present invention is that the predetermined shooting condition is shutter speed, and when the shutter speed is higher than the predetermined shutter speed, the predetermined shooting condition is switched to the first shooting sequence. When the shutter speed is set to a low speed, the second shooting sequence is switched to. Another feature of the present invention is that, when the value of the processing parameter information is set to a predetermined value or less during bracket shooting by the bracket shooting unit, the first shooting sequence control unit sets the first parameter by the shooting sequence control unit. It is characterized by having prohibition means for prohibiting switching between the photographing sequence and the second photographing sequence.

The image pickup method of the present invention is an image pickup method in which an optical image of a subject is photoelectrically converted by an image pickup element to generate electronic image data, and the generated electronic image data is recorded on a recording medium. In the case of bracket shooting in which the gain of the output signal from the image pickup device is changed when shooting, the correction data is calculated for each shooting frame even during continuous shooting. Another feature of the present invention is an imaging method in which an optical image of a subject is photoelectrically converted by an image sensor to generate electronic image data, and the generated electronic image data is recorded in a recording medium. When the subject is photographed, the correction data is calculated for each photographing frame when the gain change width is small even in the bracket photographing in which the gain of the output signal from the image sensor is changed. The feature is that it is prohibited. Another feature of the present invention is an imaging method in which an optical image of a subject is photoelectrically converted by an imaging element to generate electronic image data, and the generated electronic image data is recorded in a recording medium. Even when shooting the above-mentioned subject continuously, when shooting at a low shutter speed that does not affect the continuous shooting frame speed, the dark current noise data is taken for each shooting to correct the shot image. It is characterized by having done.

The storage medium of the present invention is characterized by recording a program for causing a computer to execute the function of each means described in any one of the above. Further, another feature of the present embodiment is that any one of the above
It is characterized by recording a program for causing a computer to execute each method described in the above item.

A computer program of the present invention is characterized by causing a computer to execute each method described in any one of the above items.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an image pickup apparatus, an image pickup method, a computer-readable storage medium, and a computer program according to the present invention will be described below with reference to the accompanying drawings.

1 and 2 show an electronic camera according to this embodiment. FIG. 1 shows the configuration of the entire camera, and FIG. 2 shows a shutter device 14 of the camera shown in FIG.
It is an enlarged view of the part.

In FIG. 1, 1 is an electronic still camera, 2
Is a photographing lens for forming an image of a subject on an image forming surface, which is detachably attached to the electronic still camera 1. The photographing lens 2 has an image forming lens 3 for forming an image of a subject on an image forming surface, and a lens driving device 4 for driving the image forming lens 3, and a diaphragm for performing exposure control. It is composed of a blade group 5 and a diaphragm driving device 6 for driving the diaphragm blade group 5.

Although the image forming lens 2 is shown in a simplified manner in the figure, it may be composed of one or a plurality of lenses, and may be a lens having a single focal length (fixed focus) or a zoom. A variable focal length such as a lens or a step zoom lens may be used.

Reference numeral 7 guides the subject image formed by the taking lens 2 to the focusing screen 8 and
It is a main mirror for transmitting a part of the light and guiding it to the focus detection device 13 through a sub-mirror 12 described later. The main mirror 7 is driven by a mirror driving device (not shown).
It is configured to be movable between a position where a subject image can be observed with a finder and a retracted position which is retracted from the optical path of the subject light flux during shooting.

Reference numeral 8 denotes a focusing screen on which the subject light beam guided by the taking lens 2 is reflected by the main mirror 7 to form an image, and a subject image is formed on the focusing screen 8 during finder observation.

Reference numeral 9 denotes an optical member for converting and reflecting the subject image formed on the focusing screen 8 into an erect image, and in this embodiment, a penta roof prism is used. Reference numeral 10 denotes an eyepiece lens device for making the subject image converted and reflected by the penta roof prism 9 into an erect normal image reach the photographer's eyes.

Reference numeral 11 denotes a photometric device for measuring the brightness of the subject image formed on the focusing screen 8 during finder observation through the penta roof prism 9, and the electronic still camera 1 of the present embodiment is the photometric device. The exposure control at the time of exposure is performed based on the output signal of the apparatus.

Reference numeral 12 is a sub-mirror for reflecting the subject light transmitted through a part of the main mirror 7 and guiding the subject light to the focus detection device 13 arranged on the lower surface of the mirror box (not shown). The sub-mirror 12 is interlocked with the main mirror 7 and a mirror drive mechanism (not shown) of the main mirror 7, and when the main mirror 7 is in a position where a subject image can be observed with a finder, a precursor focus detection device is provided. It is configured to be movable to a position where the subject light is guided to 13, and to a retracted position where the subject light is retracted from the optical path of the subject light flux during photographing.

Reference numeral 13 denotes a focus detection device, which controls the lens driving device 4 of the taking lens 2 based on the output signal of the focus detection device 13 and causes the imaging lens 3 to perform focus adjustment.

Reference numeral 14 is a shutter device for mechanically controlling the incidence of the light flux of the subject on the image plane. The shutter device 14 blocks the light flux of the subject during finder observation,
The front blade group 14a that retracts from the optical path of the subject luminous flux in response to the release signal to start exposure at the time of imaging, and the front blade group 14a that retracts from the optical path of the subject luminous flux at the time of finder observation, and at a predetermined time after the start of traveling of the front blade group 14a during imaging. Is a focal plane shutter having a rear blade group 14b that shields the subject light flux at the timing of.

In the vicinity of the aperture opening of the shutter device 14, LED elements 17a and 17b described later are provided.
Is formed with a notch or a through hole for projecting the luminous flux of the above into the front blade group 14a.

Reference numeral 15 is an image pickup device for picking up a subject image formed by the taking lens 2 and converting it into an electric signal. A known two-dimensional image pickup device is used as the image pickup device 15. CCD type, MOS type,
There are various forms such as a CID type, and any form of image pickup device may be adopted, but in the present embodiment, photoelectric conversion elements (photosensors) are two-dimensionally arranged and accumulated in each sensor. An interline CCD image pickup device in which the signal charges are output via the vertical transfer path and the horizontal transfer path is used. Further, the image pickup device 15 has a so-called electronic shutter function that controls the accumulation time (shutter time) of the charges accumulated in each sensor.

In the present embodiment, the image pickup device 15 described above is used.
As shown in FIG. 3, while protecting the image pickup area 15a of the entire screen with a cover glass 15b which is an optical protection member, the image pickup area 15a of the entire screen is located from the center to the right half surface 15c and the left half surface 15d. Is vertically divided into two, and the respective photographed image data can be simultaneously output. Reference numeral 16 denotes the image pickup device 15 and an LED 17a described later,
17b is an electric board that electrically and mechanically couples the parts 17b and holds them.

Reference numerals 17a and 17b denote light projecting means for projecting illumination light to the photographing area 15a of the image pickup device 15,
In this embodiment, an LED element is used. As shown in FIGS. 2 and 3, the LED elements 17a and 17b are located near the upper and lower side surfaces of the image sensor 15 and are located in the photographing area 15a.
Dividing line 1 dividing the right half surface 15c and the left half surface 15d
The light emitting surfaces of the LED elements 17a and 17b are arranged on the extension line of 5e so as to project the light toward the shutter device 14.

The luminous fluxes emitted from the LED elements 17a and 17b are projected onto the photographing area 15a of the image pickup device 15 with the side of the image pickup device 15 of the front blade group 14a of the shutter device 14 as a reflecting surface.

FIG. 4 shows how the LED elements 17a and 17b project light onto the photographing area 15a of the image sensor 15. As shown in FIG. 4, the right half surface 15c and the left half surface 1 of the photographing area 15a of the image sensor 15 are
The LED elements 17a, 17 are formed in a substantially symmetrical shape in a region of 5d.
The luminous flux of b is projected.

Usually, the front blade group of a shutter device of a camera using a silver salt film as a recording medium is antireflection coated to prevent fogging of the film due to stray light.
However, the electronic still camera according to the present embodiment is configured so that the electronic shutter function of the image pickup device 15 controls the accumulation time (shutter seconds) of the charges accumulated in each sensor to control the exposure time. Therefore, when the image pickup device 15 starts the accumulation,
Since the front blade group 14a is in an open state, the front blade group 14a is provided in order to prevent fogging of the imaging area due to stray light.
No need for anti-reflection coating.

Therefore, the LED elements 17a, 17 are
In order to efficiently project the emitted light flux of b to the photographing area 15a of the image pickup device 15, in the electronic still camera of the present embodiment, the front blade group 14a of the shutter device 14 has a high reflectance. It is desirable to use a material or to perform surface treatment such as painting with high reflectance and plating.

Further, the photographing area 1 of the image pickup device 15
In order to illuminate 5a in a wide range as much as possible, it is desirable to give the front blade group 14a of the shutter device 14 a diffusion characteristic. In the present embodiment, in order to achieve the above two conditions, the image pickup device 1 of the front blade group 14a is formed.
A semi-glossy white-tone coating or a semi-glossy gray-tone coating is applied to the surface on the 5 side, but sufficient illumination effect can be obtained even if only one of the conditions is achieved.

In the present embodiment, the LE
Although the luminous fluxes of the D elements 17a and 17b are directly projected and illuminated, a mask member having a specific pattern and this pattern are connected to the imaging area in the vicinity of the light emitting portions of the LED elements 17a and 17b. An optical member to be imaged may be arranged and a specific pattern may be projected instead of the illumination light.

As shown in FIG. 2, in the present embodiment, the LED elements 17a and 17b are held and electrically connected by the electric board 16 which is a holding member of the image pickup element 15. LED elements 17a, 17b
As a holding member of the shutter device 14, it is held by the camera body (not shown) or the like, and the electrical connection is made by connecting to the electric board 16 or another circuit board (not shown) by a flexible printed board / lead wire or the like. May be.

Reference numeral 18 denotes a filter member for removing high frequency components of photographing light which causes noise, and the image pickup device 1
5 is integrally held on the cover glass 15b.
The filter member 18 is made of a material having a birefringence characteristic such as quartz or lithium niobate.

FIG. 5 is a circuit block diagram showing the overall hardware configuration of the electronic still camera 1 to which this embodiment is applied. The electronic still camera 1 mainly includes a lens driving device 4 that drives the taking lens 2.
Diaphragm drive device 6, shutter device 14, image sensor 15,
In addition, a processing circuit group that processes an output signal from the image pickup device 15, an unbalance amount calculation circuit 116, a control circuit 121, and a central processing unit (hereinafter, CPU) 117.
Etc.

In FIG. 5, reference numeral 11 denotes a photometric device for performing AE (automatic exposure) processing. As described above, the light beam incident on the taking lens 2 is processed by the single-lens reflex system, the diaphragm blade group 5, the main mirror. 7, and the exposure state of the image formed as the optical image can be measured by making the light incident on the photometric device 11 via the photometric lens (not shown).

Reference numeral 13 denotes the above-mentioned focus detection device for performing AF (autofocus) processing. 100 ~, 11
6, 118, and 120 to 125 are the image pickup devices 15
It is a processing circuit group for processing the image output signal from the.

In FIG. 5, the light flux of the subject that has passed through the taking lens 2 is regulated in its light quantity by the diaphragm blade group 5 and the shutter device 14, and is projected and imaged on the image pickup device 15. The image pickup device 15 having two outputs (CH1 and CH2) operates at a predetermined frequency when driven by the driver means 100, and separates the entire screen vertically into two parts (15c, 15d) separately. It is configured to output captured image data. Also, TG / S
SG 101 is a timing generation circuit that outputs a vertical synchronization signal VD and a horizontal synchronization signal HD, and simultaneously supplies a timing signal to each circuit block.

The image output of the right half surface 15d of the image pickup device 15 is input to the CDS / AGC circuit 103 via the CH1 output, and the output of the CCD or the like is performed by performing a known method such as correlated double sampling. The reset noise and the like included in is removed, and the AGC circuit for amplifying the output up to a predetermined signal level is activated. By inputting the output after the AGC to the A / D conversion circuit 105, it is converted into a digital signal and an output of AD-CH1 is obtained.

Similarly, the left half surface 15c of the image pickup device 15 is
The image output of is input to the CDS / AGC circuit 102 via the CH2 output, and a similar method such as correlated double sampling is performed here to remove reset noise and the like included in the output of the CCD and the like. The AGC circuit for amplifying the output to a predetermined signal level is activated. This AGC
By inputting the subsequent output to the A / D conversion circuit 104, it is converted into a digital signal and an output of AD-CH2 is obtained.

After the left and right outputs from the image pickup device 15 are separately converted into digital data, the two outputs are respectively passed through the memory controllers 106 and 108 to the memory 107,
It will be sequentially stored in 109.

When a calibration operation described later is executed, AD-CH1 and AD-CH2
Are simultaneously input to the unbalance amount calculation circuit 116, the unbalance amount of both outputs is calculated by a method described later, and optimum correction data is determined and stored in the correction data memory.

The memory controller 106 and 1
Reference numeral 08 is a normal time division, and the memories 107 and 109 are
Since it is possible to continuously read and write data to and from the memory 10,
It is possible to read the data written in the memories 107 and 109 at different timings while writing to the data written in 7 and 109, in the order of writing.

First, for the CH1 side output of the image pickup device 15, data is continuously read from the memory 109 under the control of the memory controller 108,
It is input to the offset adjustment circuit 111. Here, a predetermined offset output OF1 calculated and set by the unbalance amount calculation circuit 116 is connected to the other input of the offset adjustment circuit 111, and both signals are added inside the offset adjustment circuit 111. .

Next, the output of the offset adjusting circuit 111 is input to the gain adjusting circuit 113. Here, the other input of the gain adjusting circuit 113 is calculated and set by the unbalance amount calculating circuit 116. And a predetermined gain output GN1 is connected to the gain adjusting circuit 1
Both signals are multiplied inside 13.

Similarly, for the CH2 side output of the image pickup device 15, data is continuously read from the memory 107 and input to the offset adjusting circuit 110 under the control of the memory controller 106. Here, a predetermined offset output OF2 calculated and set by the unbalance amount calculation circuit 116 is connected to the other input of the offset adjustment circuit 110, and the addition of both signals is performed inside the offset adjustment circuit 116. I do.

Next, the output of the offset adjusting circuit 110 is input to the gain adjusting circuit 112. Here, the other input of the gain adjusting circuit 112 is calculated and set by the unbalance amount calculating circuit 116. And a predetermined gain output GN2 is connected to the gain adjusting circuit 1
Both signals are multiplied inside 12.

In this way, the image data output after the unbalance amount generated between the two outputs is corrected by the unbalance amount calculating circuit 116 is converted into one image data by the image synthesizing circuit 114 (the left and right outputs are converted into One output), and the camera DSP 115 at the next stage performs predetermined color processing (color interpolation processing, γ conversion).

Further, the camera DPS115 performs a predetermined arithmetic processing using the captured image data, and also performs TTL AWB (auto white balance) processing based on the obtained arithmetic result.

The camera DSP 115 reads each pixel data for one frame from the memories 107 and 109 by the control signal from the CPU 117, and the image synthesizing circuit 11
After converting into one image data with 4, camera DS
Work memory 1 once after performing image processing in P115
Store in 21.

Subsequently, the data in the work memory 121 is compressed by the compression / expansion means 122 according to a predetermined compression format, and the result is recorded in the external non-volatile memory 123 (usually a flash memory or other non-volatile memory). Use). External non-volatile memory 123
Is configured to be attachable / detachable to / from the electronic still camera 1, and whether or not it is attached can be detected by the recording medium attachment / detachment detection means 132.

Reference numeral 124 is a video memory, and 125 is a TFT.
The camera D is a monitor display unit including an LCD and the like.
The image data written in the video memory 124 from the SP 115 can be displayed one by one by the monitor display means 125. On the contrary, when observing the image data that has been captured, the data compressed and stored in the external non-volatile memory 123 is expanded through the compression / expansion means 122 into the data for each normal imaging pixel, and the result is displayed. By transferring to the video memory 124, the monitor display means 12
It can be displayed through 5.

The monitor display means 125 is the CP
The display can be turned ON / OFF arbitrarily according to the instruction of U117, and when the display is turned OFF, the power consumption of the electronic still camera 1 can be significantly reduced.

As described above, during normal photographing, the image pickup device 1
The output from 5 is converted into actual image data through various process processing circuits in almost real time, and the result is converted into the work memory 121 or the video memory 124.
It is configured to output to.

Next, the control during the calibration operation for calculating the correction amount by the unbalance amount calculation circuit 116, which is required at the time of screen composition in the present embodiment, will be described.

During the calibration operation, the unbalance amount calculation circuit 116 is operated by the CPU 117 described later.
Instruct to start the calibration operation to
The driver 120 outputs a lighting instruction for the calibration LED elements 17a and 17b for a predetermined time.

The LED elements 17a and 17b cause the driver means 120 to project light onto the image pickup element 15. The image pickup device 15 includes the LED devices 17a and 17a.
According to the lighting time of b, the accumulation of the image (FIG. 4) by the illumination light is started, and the CD is output via CH1 output and CH2 output.
The signal is output to the S / AGC circuits 103 and 102, and the output signal is processed as described above.

Further, the unbalance amount calculation circuit 116.
Then, the unbalance amount calculation circuit 116 calculates the unbalance amount by the method described later based on the output data of the image of the illumination light projected by the LED elements 17a and 17b (FIG. 4), and the appropriate correction data is obtained. To decide. Further, the calculated unbalance amount, the correction data, and the like are stored in the correction data memory 118 connected to the unbalance amount calculation circuit 116, and stored and retained.

At this time, when it is determined that the image output from the image pickup device 15 has a clear abnormality, for example,
When image output cannot be obtained from a portion illuminated by the projection of the LED elements 17a and 17b, the display / warning means 133 to be described later notifies the photographer that proper calibration cannot be performed. It has become. Therefore, the photographer can recognize any abnormality of the camera (failure of the image sensor, the signal processing circuit, the LED, etc.) or the like based on this result.

Here, the unbalance amount calculation circuit 11
The specific configuration of No. 6 will be described using the circuit shown in FIG. In FIG. 6, first, the outputs AD-CH1 and AD-CH2 of the A / D conversion circuit are input to the average value calculation circuits 140, 141, 142. Here, the average value calculation circuit averages the data for each pixel over a predetermined range, and the region selection circuit 143 executes this region setting.

The area selection circuit 143 determines the effective range of the data for each pixel output from the image pickup device 15 with reference to the VD / HD signal from the TG / SSG 101 shown in FIG. The timing for allowing the input signal to be averaged by the calculation circuit is set.

For example, the average value calculation circuit 140 calculates the average value of each pixel data existing in the portion of the illumination section a by the LED elements 17a and 17b shown in the image pickup area 15a of the image pickup element 15, and The average value calculation circuit 142 calculates the average value of each pixel data existing in the portion of the illuminating part b by the LED elements 17a and 17b shown in the image pickup area 15a of the image pickup element 15.

On the other hand, the average value calculation circuit 141 calculates the average value of each pixel data existing in both the illumination parts a and b by the LED elements 17a and 17b shown in the imaging area 15a of the imaging element 15. calculate.

Therefore, in this case, the average value of the pixel data of the predetermined range existing in the left half 15c of the image sensor 15 shown in FIG. 5 and the pixel data of the predetermined range existing in the right half 15d of the image sensor 15 shown in FIG. The average value and the average value of the pixel data in a predetermined range existing on both the left and right sides of the image sensor 15 are calculated as the average value calculation circuits 140, 141, and 1.
It will be calculated at 42.

Next, the average value calculation circuits 140 and 14
The respective outputs of 1 and 142 are V2, V1 + 2, and V1, and each output is connected to the division circuit 144, 1 connected to the next stage.
Each division is performed by 45.

First, in the division circuit 144, V1 + 2 /
The calculation of V2 is performed, and a value substantially proportional to this result is output from the correction data calculation circuit 148 as a GN2 signal.
Similarly, the division circuit 145 performs an operation of V1 + 2 / V1 and outputs a value substantially proportional to this result from the correction data calculation circuit 149 as a GN1 signal.

GN1 and GN2 calculated by the above method
Since these signal outputs are input to the gain adjustment circuits 113 and 112 shown in FIG. 5, respectively, actual correction is performed here so that the output levels from both channels match.

On the other hand, the average value calculation circuits 140 and 14
Subtraction circuit 1 in which each output of Nos. 1 and 142 is connected to the next stage
46 and 147 respectively perform subtraction. First, the subtraction circuit 1
At 46, a calculation of V1 + 2-V2 is performed, and a value substantially proportional to this result is output from the correction data calculation circuit 150 as an OF2 signal. Similarly, in the subtraction circuit 147, V1 + 2
The calculation −V1 is performed, and a value substantially proportional to this result is output from the correction data calculation circuit 151 as an OF1 signal.

OF1 and OF2 calculated by the above method
The respective signal outputs are input to the offset adjusting circuits 111 and 110 shown in FIG. 5, respectively. Therefore, actual correction is performed here so that the output levels from both channels match.

The output signals GN1, GN2, OF1, OF relating to the unbalance amount calculated by the above method.
2 is output to the correction data memory 118 connected to the unbalance amount calculation circuit and stored and held.

Until the end, the above-mentioned two methods are the average value of the data of a predetermined range existing in the left half 15c and the data of a predetermined range existing in the right half 15d of the pixel data output from the image sensor. Average value and left half 15
It is intended to correct the imbalance between the two outputs of the image pickup element by using each value of the average value of the data of c and the data in a predetermined range existing in the right half 15d.

In the case of the above method, there are two kinds of cases, that is, the case where the gain adjustment is performed on the data between the two outputs and the case where the offset adjustment is performed. The balance adjustment may be performed, or only one of them may be selected to perform the unbalance adjustment.

Reference numeral 117 denotes a central processing unit (hereinafter, CPU) which is a system control circuit for controlling the entire electronic still camera 1 of this embodiment. CPU 11
Reference numeral 7 is a photometric device 11, a focus detection device 13, a control circuit 119, an unbalance amount calculation circuit 116, and the LE.
Driver means 120 for driving the D elements 17a, 17b,
Connected with the release switch (SW1) 125, the release switch (SW2) 126, the shooting mode setting 128, the single / continuous shooting switch 129, the operation unit 130, the power switch 131, the recording medium attachment / detachment detection 132, the display / warning means 119, etc. Therefore, various calculations such as the exposure value and the focus position of the photographing lens 2 are performed according to a predetermined algorithm, and control of automatic exposure control, auto focus, auto strobe, etc. is comprehensively managed.

119, based on the automatic focus information output from the CPU 117, drives and controls the lens driving device 4 of the photographing lens 2 to drive the imaging lens 3 to the in-focus position, and also outputs exposure control information. Based on this, the aperture driving device 6 of the taking lens 2 is drive-controlled to set the aperture blade group 5 to the set aperture value, and the opening / closing timing of the shutter device 14 is linked with the drive control information of the image sensor 15. Is a control circuit for controlling the.

126, 127, 128, 129, 13
Reference numerals 0 and 131 are operating means for inputting various operation instructions to the CPU 117, and are composed of a single or a combination of a switch, a dial, a touch panel, pointing by visual axis detection, a voice recognition device, and the like.

Reference numeral 126 is a release switch (SW1) which is turned on during the operation of a shutter button (not shown) and is a pre-shooting preparation operation such as AF (auto focus) processing, AE (auto exposure) processing, and AWB (auto exposure). It is instructed to start operations such as white balance) processing and EF (flash dimming) processing. Further, in the present embodiment, the calibration operation / processing start of the image pickup device 15 is instructed.

Reference numeral 127 is a release switch (SW2) which is turned on when the operation of a shutter button (not shown) is completed and instructs the start of an exposure operation which is a photographing sequence. Further, in the present embodiment, an instruction to stop the calibration operation / process of the image sensor 15 is given.

Reference numeral 128 denotes a photographing mode setting means, which is composed of a mode dial switch or the like, and has an automatic photographing mode, a program photographing mode, a shutter speed priority photographing mode,
Aperture priority shooting mode, Manual shooting mode, Depth of focus priority (depth) shooting mode, Portrait shooting mode,
Each function shooting mode such as landscape shooting mode, close-up shooting mode, sports shooting mode, night view shooting mode, and panorama shooting mode can be switched and set.

Reference numeral 129 denotes a single-shot / continuous-shoot switch, which is a single-shot mode in which one frame is shot and a standby state is entered when the release switch (SW2) 127 is pressed, and the release switch (SW2) 127 is pressed. It is possible to set a continuous shooting mode in which shooting is continuously performed during the period.

Reference numeral 130 denotes an operation unit including various buttons and a touch panel, which includes a menu button, a set button, a macro button, a multi-screen playback page break button, a flash setting button, a single-shot / continuous-shot / self-timer switching button,
Menu move + (plus) button, menu move- (minus) button, playback image move + (plus) button, playback image- (minus) button, shooting image quality selection button, exposure compensation button, ISO setting button, date / time setting It has a button, a selection / switch button for setting selection and switching of various functions when performing shooting and reproduction such as panorama mode.

Also, when performing shooting and reproduction in panorama mode, etc., determination of various functions and determination of setting execution /
Execute button, image display ON / OFF switch to set ON / OFF of the monitor display section 125, quick review ON / OFF switch to set the quick review function to automatically play back image data taken immediately after shooting, compression rate of JPEG compression Each function such as compression mode switch, playback mode, multi-screen playback / erasure mode, PC connection mode, which is a switch for selecting the CCD RAW mode in which the image sensor signal is directly digitized and recorded on the recording medium One-shot AF mode and release switch (SW1) will start autofocus operation if you press the release switch (SW1) ) You can set the Servo AF mode to continue the autofocus operation continuously while pressing It has a wear AF mode setting switch and the like.

Further, in the present embodiment, the exposure value is set as a parameter, and the AE bracket mode, which is an automatic exposure bracket for performing stepwise exposure with a predetermined exposure width by changing the aperture value at the shutter speed. ), And an ISO value as a parameter, and an automatic exposure bracket mode (ISO bracket mode) in which stepwise exposure with a predetermined exposure width is performed, and a color temperature value is set as a parameter, and stepwise exposure with a predetermined color temperature range is performed. Each bracket setting switch for the white balance bracket mode (WB bracket mode) is provided.

Further, each of the functions of the plus button and the minus button is provided with a rotary dial switch, so that it is possible to more easily select numerical values and functions.

Reference numeral 131 denotes a power switch, which can switch and set each mode of power-on and power-off of the electronic camera 1. Reference numeral 132 denotes a recording medium attachment / detachment detection unit that detects whether or not the nonvolatile memory 123, which is a recording medium, is attached to the camera.

Reference numeral 133 denotes a display / warning unit for a liquid crystal display device, a speaker, etc., which displays operating states, messages, warnings, etc. by using characters, images, voices, etc. according to the execution of the program by the CPU 117. A single or a plurality of locations are provided near the operation section of the camera 1 at a position where it is easily visible, and are configured by a combination of, for example, an LCD, an LED and a sounding element.

Further, the display / warning unit 133 is installed in an optical finder (not shown) for some of its functions.
Among the display contents of the display / warning unit 133, what is displayed on the LCD or the like is, for example, a single shot / continuous shooting display, a self-timer display, a compression ratio display, a recording pixel number display, a recording number display, and a remaining image capture. Number display, shutter speed display, aperture value display, exposure compensation display, flash display, red-eye reduction display, macro shooting display, buzzer setting display,
Battery remaining amount display for clock, battery remaining amount display, error display, information display with a plurality of digits, detachable state display of the non-volatile memory 123 as a recording medium, detachable state display of the taking lens 2, communication operation display, date・ Time display, display showing connection status with external computer, etc.

Among the display contents of the display / warning unit 133, what is displayed in an optical viewfinder (not shown) is, for example, a focus display, a shooting preparation completion display, a handshake warning display, a flash charging display, a flash charging. Completion display,
Shutter speed display, aperture value display, exposure compensation display,
Recording medium writing operation display, etc.

Further, among the display contents of the display / display unit 133, what is displayed on the LED or the like is, for example, a focus display, a shooting completion display, a handshake warning display, a handshake warning display, a flash charge display, a flash charge. There are a completion display, a recording medium writing operation display, a macro photography setting notification display, a secondary battery charge status display, and the like.

Among the display contents of the display / warning unit 133, what is displayed on a lamp or the like is, for example, a self-timer notification lamp or the like. This self-timer notification lamp may be used in combination with the AF auxiliary light.

Next, the operation of the electronic still camera of this embodiment will be described with reference to FIGS. 7 and 8 show an electronic still camera 1 according to the embodiment of the present invention.
The flowchart of the main routine of is shown.

The operation of the electronic still camera 1 will be described with reference to FIGS. 7 and 8. Upon power-on such as battery replacement, the CPU 117 initializes flags, control variables, and the like, and makes necessary initial settings in each unit of the electronic still camera 1 (S101).

The CPU 117 has a power switch 131.
If the power switch 131 is set to power off (step S102), the display of each display unit is changed to the end state, and necessary parameters and setting values including flags and control variables are set. , Setting mode is the above CPU1
The data is recorded in a non-volatile memory (not shown) mounted in the memory 17, and predetermined termination processing such as cutting off unnecessary power of each part of the electronic still camera 1 is performed (step S103), and then the process returns to step S102.

If the power switch 131 has been set to power ON (step S102), the CPU 11
Reference numeral 7 determines whether there is a problem in the operation of the electronic still camera 1 due to the remaining capacity of the power source composed of a battery or the like or the operating condition (step S104), and if there is a problem, the display / warning unit 133 is used. After a predetermined warning is displayed by an image or sound (step S105), the process returns to step S102.

If there is no problem with the power source (step S10)
4) The CPU 117 determines the mode setting position by the mode dial, which is the photographing mode setting means 128, and if the mode dial is set to the photographing mode (step S106), the process proceeds to step S108.

If the mode dial is set to any other mode (step S106), the CPU 11 is operated.
7 executes the process according to the selected mode (step S107), and when the process is completed, returns to step S102.

The CPU 117 determines whether or not the non-volatile memory 123, which is a recording medium, is installed, acquires management information of image data recorded in the non-volatile memory 123, which is a recording medium, and is a recording medium. It is determined whether the operation state of the non-volatile memory 123 has a problem in the operation of the electronic still camera 1, particularly the recording / reproducing operation of image data with respect to the recording medium (step S108),
If there is a problem, a predetermined warning is displayed by an image or sound using the display / warning unit 133 (step S10).
5) and returns to step S102.

Determination as to whether or not the non-volatile memory 123 as a recording medium is mounted, acquisition of management information of image data recorded in the non-volatile memory 123 as a recording medium, and non-volatile memory 123 as a recording medium. As a result of determining whether or not there is a problem in the operation state of the electronic still camera 1, particularly the recording / reproducing operation of the image data with respect to the recording medium (step S108), if there is no problem, the process proceeds to step S109.

The CPU 117 allows the photographer to use the ISO bracket mode and WB
Whether or not the bracket mode is set is determined (step S109). When the bracket mode is set, the rotary dial having the functions of the brass button and the minus button is used for bracket shooting. The bracket setting value (ISO value, color temperature value) is input (step S110).

Based on the bracket setting value set here, bracket shooting is performed while changing the ISO value in the ISO bracket mode, and bracketing is performed while changing the color temperature value (Kelvin value) in the WB bracket mode. Take a picture. If the bracket mode is not set, the process proceeds to step S111.

The bracket setting value set by the bracket mode setting is stored in the internal memory of the CPU 117 and is stored until bracket photographing of a predetermined number of frames is completed. When the bracket photographing is completed, the bracket setting value is cleared and the bracket mode is set. To release.

The CPU 117 checks the setting state of the single shooting / continuous shooting switch 129 for setting single shooting / continuous shooting (step S111), and if single shooting is selected, the single shooting / continuous shooting flag is set. Is set to single shot (step S11
2) If the continuous shooting is selected, the single shooting / continuous shooting flag is set to continuous shooting (step S113), and if the flag setting is completed, the process proceeds to step S114.

According to the single-shot / continuous-shooting switch 129, when the release switch (SW2) 127 is pressed, a single-shooting mode in which one frame is shot and the standby state is set, and the release switch (SW2) 127 is pressed. The setting can be switched by arbitrarily switching between the continuous shooting mode in which continuous shooting is continued while the shooting is in progress.

The state of the single-shot / continuous-shot flag is C above.
It is stored in the internal memory of the PU 117. The CPU 117
Uses the display / warning unit 133 to display various setting states of the electronic still camera 10 by image and sound (step S114). In addition, the image display of the monitor display unit 125
If it is ON, the monitor display unit 125 is also used to display various setting states of the electronic still camera 1 by images and sounds. If the release switch (SW1) 126 is not pressed (step S121), step S10
Return to 2.

If the release switch (SW1) 126 is pressed (step S121), the CPU 117 is operated.
Performs distance measurement processing to focus the taking lens 2 on the subject, performs light measurement processing to determine the aperture value and shutter time, performs distance measurement / light measurement processing (step S122),
It proceeds to step S123. In the photometric processing, the flash is set if necessary. Details of the distance measurement / photometry processing step S122 will be described later with reference to FIG.

Further, the CPU 117 carries out distance measurement and photometry processing (step S122) in response to the pressing operation of the release switch (SW1) 126, and simultaneously outputs from the output terminals of the left and right screens of the image pickup device 15. The calibration process (step S123) for accurately detecting the unbalance amount of the left and right image data and calculating the correction data is started.

As described above, the release switch (SW
1) In response to the pressing operation of 126, the distance measurement / photometry processing (step S122) and the calibration processing (step S123) are performed, and then the process proceeds to step S124, whereby the release switch (SW2) 127 is pressed in step S124. It is possible to eliminate the influence on the release time lag when it is hit.

The above calibration process (step S
123) The unbalance amount calculation is performed using the calibration data captured in 123), and the correction data calculation process is performed to combine the left and right image data of the image sensor 15 into one screen by the screen combining circuit 114. The captured image data can be corrected accurately. Details of the calibration processing step S123 will be described later with reference to FIG.

If the release switch (SW2) 127 is not pressed (step S124), the release switch (SW1) 126 is released (step S124).
126), the current calibration process (step S
123) is repeated.

The above calibration process (step S
123) makes it possible to accumulate more correction data by repeating the operation at a predetermined time interval, and the reliability of the correction data is improved, so that the accuracy at the time of screen composition is significantly improved. You can

If the release switch (SW1) 126 is released (step S126), the process returns to step S102 in FIG. Release switch (SW2) 1
If 27 is pressed (step S124), the CP
U117 performs the calibration process (step S12
Regardless of the processing status of 3) (whether the calculation of the unbalance amount and the calculation of the correction data is completed), the calibration processing is stopped (step S125), and the process proceeds to step S127.

In this way, the release switch (SW
2) In response to the pressing operation of 127, the calibration process (step S123) is forcibly stopped, and the process proceeds to steps S127 and S129, whereby the release time lag when the release switch (SW2) 127 is pressed. Can be eliminated.

Next, it is judged whether or not there is an image storage buffer area capable of storing the photographed image data in the memories 107 and 109 (step S127), and the memories 107 and 1
If there is no area for storing new image data in the image storage buffer area of 09, a predetermined warning is displayed by the image / voice using the display / warning unit 133 (step S128), and then to step S102. Return.

For example, immediately after the maximum number of continuous shots that can be stored in the image storage buffer areas of the memories 107 and 109 has been taken, the nonvolatile memory is read from the memories 107 and 109 and is a storage medium during image processing. Sex memory 123
The first image to be written to is not yet recorded in the non-volatile memory 123, which is still a storage medium, and is still 1
An example of this state is a case where a free space of one sheet cannot be secured in the image storage buffer areas of the memories 107 and 109.

When the photographed image data is compressed and then stored in the image storage buffer area of the work memory 121, the amount of image data after compression differs depending on the setting of the compression mode. In step S127, it is determined whether the storable area is on the image storage buffer area of the work memory 121.

If the memories 107 and 109 have an image storage buffer area capable of storing photographed image data (step S127), the CPU 117 reads out the image pickup signal accumulated for a predetermined time from the image pickup device 15,
The above-mentioned image processing process is performed to execute the memory 107, 10
A photographing process of writing photographed image data in a predetermined area 9 is executed (step S129). Details of this photographing processing step S129 will be described later with reference to FIG.

When the photographing process step S129 is completed, the CPU 117 causes the release switch (SW
2) Before the operation 127, it is determined whether or not the calibration process (step S123) has been completed at least once (step S130). As described above, in the electronic still camera 1 according to the present embodiment, in order to secure the release time lag, the calibration is performed by pressing the release switch (SW2) 127 even during the calibration process (step S123). Operation processing (step S123) is canceled.

Therefore, it is detected whether or not the photographing has been performed without calculating the unbalance amount for the photographed image data and the correction data by the calibration process (step S123), and then performing the calibration process. (Step S123) is completed at least once, the unbalance amount for the captured image data is calculated, the correction data is calculated, and the unbalance amount / correction data is stored in the correction data memory-118. If so, the process proceeds to step S131.

The state of the single-shot / continuous-shot flag stored in the internal memory of the CPU 117 is judged (step S13).
1) If continuous shooting has been set, the process proceeds to step S132. The CPU 117 determines whether or not the shooting is in the bracket shooting mode (step S132), and if the current shooting is set to the bracket shooting mode and the bracket shooting is still in progress, the step S132 is performed.
Proceed to 134.

The CPU 117 reads out the bracket setting value (step S110) input by the bracket mode setting (step S109) from the internal memory so as to correct the exposure control value of the next frame and the like (step S134). .

Next, it is judged whether or not the set bracket value is less than or equal to the predetermined value (X) (step S135). Here, the degree of gain change with respect to the output signal of the image pickup device is determined from the set bracket value, and the bracket value (gain change value) is a small value equal to or smaller than a predetermined value (for example, 1 / 3Ev in ISO bracket mode). Bracket shooting by changing the ISO), there is little effect on the error of the unbalance amount calculated by gain amplification.

Therefore, the calibration process (step S136) is not performed again, and the unbalance amount calculated by the calibration process (step S123) stored in the correction data memory-118 is calculated. The correction data is held by controlling the correction data memory 118 through the unbalance amount calculation circuit 126 (step S133), and the correction data used for the image data of the previous frame is used.

Further, the bracket value (gain change value) is larger than a predetermined value (for example, bracket shooting by ISO change at 2/3 Ev or more in ISO bracket mode).
If so, the influence of the error on the unbalance amount calculated by the gain amplification amount becomes large,
It is necessary to perform the calibration process (step S136) again.

The CPU 117 determines whether or not the bracket photographing mode is selected (step S13).
2) If it is determined that the current shooting is not shooting in the bracket shooting mode, the calibration process (step S136) is not performed again, and the correction data stored in the correction data memory-118 is stored. The unbalance amount and the correction data calculated by the calibration process (step S123) are passed through the unbalance amount calculation circuit 126, and the correction data memory 118.
Is controlled (step S133), and the correction data used for the image data of the previous frame is used.

If the release switch (SW2) 127 has been pressed (step S137), the CPU 117
Again, in order to continue the shooting operation, the memories 107, 10
9 is checked (step S127), and the next frame is photographed (step S125).

As described above, the calibration process (step S123) is executed at least once in step S130, the unbalance amount and the correction data are calculated and stored, and the continuous shooting is set in step S131. When the bracket photographing is being executed, according to the correction amount of the bracket photographing, when the correction amount is small, it is not necessary to perform the calibration process in step S136 for each photographing frame, and therefore, the photographing process of the next frame ( Step S12
9) can be immediately executed, and the continuous shooting frame intervals can be made almost constant.

When the correction amount is large, the calibration process is performed for each image frame, whereby more accurate imbalance amount and correction data are calculated and stored, and the screen configuration can be reliably performed.

In the present embodiment, the presence / absence of the calibration process is determined according to the correction amount of bracket shooting, but at the time of bracket shooting, it does not depend on the correction amount. You may comprise so that a calibration process may be performed. In this case, it is possible to make the intervals between the continuous shooting frames almost constant, and by performing the calibration process for each shooting frame, more accurate unbalance amount and correction data are calculated and stored to ensure the accuracy. Screen configuration can be done.

If single shot has been set (step S
131), and proceeds to step S141. When it is determined that the calibration process (step S123) has not been completed at least once (step S130) after completion of the imaging process (step S129), calculation of an unbalance amount for the captured image data and calculation of correction data. Is not performed and the unbalance amount / correction data is not stored in the correction data memory-118, step S
Proceed to 138.

The state of the single-shot / continuous-shot flag stored in the internal memory of the CPU 117 is judged (step S13).
8) If continuous shooting has been set, the process proceeds to step S139. If the release switch (SW2) 127 is pressed (step S139), the CPU 117 recognizes that continuous shooting is being performed, and determines whether or not bracket shooting is being performed (step S132), and the current shooting is performed. If it is determined that the shooting is not performed in the bracket shooting mode, the calibration process is performed again (step S13).
6) Without performing the above, release switch (SW
2) If 127 is pressed (step S137), the CPU 117 checks the memories 107 and 109 again (step S127) to continue the shooting operation, and performs the next frame shooting process (step S125). .

When the CPU 117 determines that the shooting is in the bracket shooting mode (step S132), the CPU 117 sets the bracket mode (step S1).
09) input bracket setting value (step S
110) is read from the internal memory and set in order to correct the exposure control value and the like of the next frame (step S134).

It is determined whether the set bracket value is less than or equal to the predetermined value (X) (step S135),
As described above, it is determined whether or not the calibration process is executed, and the process proceeds to the next frame shooting process (step S127).

As described above, even if the calibration process (step S123) is not completed in step S130 and the unbalance amount and the correction data are not calculated / stored, continuous shooting is set in step S138. In addition, if bracket shooting has been executed, the calibration process is executed in step S136 for each shooting frame, and the unbalance amount and correction data can be reliably calculated and stored, and the screen configuration can be surely displayed. It can be performed.

If single shot has been set (step S138), the process proceeds to step S140, calibration processing is performed, calculation of the unbalance amount for the captured image data, calculation of correction data, and correction data After the storage of the unbalance amount / correction data in the memory-118 is completed, the process proceeds to step S141 to start the development processing of the captured image.

Further, the release switch (SW2) 12
If 7 is not pressed (step S139), the above C
The PU 117 determines that the continuous shooting has been canceled, and the step S1
In step S40, the calibration process is performed, the unbalance amount for the captured image data is calculated, the correction data is calculated, and the storage of the unbalance amount / correction data in the correction data memory-118 is completed. Then, the process proceeds to step S141. Start the development processing of the captured image.

In this way, the photographing process (step S12
9) before the calibration process (step S12
Even if the unbalance amount and the correction data cannot be calculated by 3), if the shooting is temporarily stopped after the shooting processing (step S139), regardless of continuous shooting or single shooting, the calibration processing ( Since step S127) is executed to calculate and store the unbalance amount and the correction data, it is possible to correct the captured image data accurately. This calibration operation (step S136,
Details of step S140) will be described later with reference to FIG.

In the developing process (step S141),
The CPU 117 controls the unbalance amount calculation circuit 116 to read the correction data necessary for combining the calculated and stored shooting screens from the correction data memory-118.

Further, the CPU 117 uses the memory controllers 106 and 108 to cause the memories 107 and 10 to operate.
The photographed image data written in the predetermined area 9 is read out from the correction data memory, and the correction data (OF
1, OF2, GN1, GN2), and the offset adjusting circuits 110 and 111 and the gain adjusting circuits 112 and 11 are used.
3. After performing the correction process according to 3, the screen synthesis circuit 11
In 4, the screen composition processing of the photographing data is performed.

The combined photographing data is stored in the camera DSP 11
Input to 5, AWB (auto white balance) processing,
Various development processes including a gamma conversion process and a color conversion process are performed (step S141).

Then, the CPU 117 reads the written image data by the camera DSP 115 into a predetermined area of the work memory 121, and performs the image compression processing according to the set mode by the compression / expansion circuit 122 (step S142). , The image data that has been photographed and has been subjected to a series of processing is written in the empty image portion of the image storage buffer area of the work memory 121.

Along with the execution of a series of photographing, the image data stored in the image storage buffer area of the work memory 121 is read out and stored in the nonvolatile memory 123 which is a recording medium such as a memory card or a compact flash (R) card. The recording process for writing is started (step S143).

This recording start processing is performed by the work memory 12
Each time new writing of image data that has been photographed and has completed a series of processing is written in the empty image portion of the first image storage buffer area, that image data is executed.

While the image data is being written to the non-volatile memory 123 which is a recording medium, in order to clearly indicate that the writing operation is being performed, for example, the display / warning unit 133 blinks an LED or the like. The recording medium writing operation is displayed.

The development process (step S141) is completed for all of the photographed image data written in the predetermined areas of the memories 107 and 109, and the compression process (step S14).
2) When the recording start process (step S143) is performed, the correction data used in the image process (step S141) becomes unnecessary.

Therefore, the CPU 117 controls the unbalance amount calculation circuit 116 to erase the correction data stored in the correction data memory 118, or
Alternatively, a correction data reset process for canceling the correction data (OF1, OF2, GN1, GN2) output from the unbalance amount calculation circuit 116 (step S144)
I do

Next, the CPU 117 causes the release switch (SW1) 12 to respond to photographing the next frame.
It is determined whether 6 is pressed (step S14).
5). If the release switch (SW1) 126 has been released (step S145), step S145
Return to 102.

If the release switch (SW1) 126 is in the pressed state (step S145), the calibration process (step S123) is started again for photographing the next frame, and the next photographing is performed. . If the release switch (SW1) 126 is released (step S126), the process returns to step S102.

FIG. 9 is a detailed flowchart of the distance measuring / photometric processing in step S122 of FIG. In addition,
In the distance measurement / photometry processing, the CPU 117 outputs a control signal to the control circuit 119 based on the output signals of the focus detection device 13 and the photometry device 11, so that the control circuit 119 causes the lens drive device 4 and the aperture drive device. 6. Drive control of the shutter device 14 is performed.

The CPU 117 starts the AF (autofocus) process using the focus detection device 13 (step S201). In addition, the CPU 117 causes the light beam that has entered the photographing lens 2 to enter the focus detection device 13 via the diaphragm blade group 5, the main mirror 7, and the sub mirror 13, thereby combining the images formed as optical images. The focus state is determined, and the focus detection device 13 is driven while driving the imaging lens 3 of the taking lens 2 using the focus detection means 13 until it is determined that the distance measurement (AF) is in focus (step S203).
AF control for detecting the in-focus state is executed by using (step S202).

When it is determined that the distance measurement (AF) is in focus (step S203), the CPU 117 determines the in-focus distance measurement point from the plurality of distance measurement points in the photographing screen and determines the determined distance measurement. The distance measurement data and / or the setting parameters are stored in the internal memory of the CPU 117 together with the distance point data, and the process proceeds to step S205.

Subsequently, the CPU 117 causes the photometric device 1
1 is used to start the AE (automatic exposure) process (step S205). The CPU 117 makes a light beam incident on the taking lens 3 an object image formed on the focusing screen 8 by the diaphragm blade group 5 and the main mirror 7.
The brightness is made incident on the photometric device 11 through the penta roof prism 9 and a photometric lens (not shown) to measure the exposure state of the image formed as an optical image.
Until it is determined that the exposure (AE) is appropriate (step S20
6) The photometric processing is performed by the CPU 117 (step S206).

When the exposure (AE) is judged to be appropriate (step S207), the CPU 117 stores the photometric data and / or the setting parameter in the internal memory of the CPU 117, and is the distance measuring / photometric processing routine in step S1.
22 ends.

The CPU 117 determines the aperture value (Av value) according to the exposure (AE) result detected in the photometry processing step S206 and the photographing mode set by the mode dial which is the photographing mode setting means 128. , Shutter speed (Tv value) is determined.

Then, according to the shutter speed (Tv value) determined here, the CPU 117 causes the image sensor 1
The charge accumulation time of 5 is determined, and the photographing processing is performed with the same charge accumulation time.

FIG. 10 is a detailed flowchart of the photographing process in step S129 of FIG. In the photographing process (step S129), the CPU 11
When the control circuit 119 outputs a control signal to the control circuit 119, the control circuit 119 controls the drive of the diaphragm drive device 6 and the shutter device 14.

The CPU 117 moves the main mirror 7 to the mirror-up position by a mirror driving means (not shown) (step S301), and at the same time, the CPU 117.
According to the photometric data stored in the internal memory of, the control circuit 119 controls the aperture driving device 4 to drive the aperture blade group 5 to a predetermined aperture value (step S302).

After performing the charge clearing operation of the image pickup device 15 (step S303), the CPU 117 controls and drives the shutter device 14 by the control circuit 119 to open the front blade group 14a (step S304).

Since the electronic still camera 1 of this embodiment has the electronic shutter function as described above,
The charge accumulation of the image pickup device 15 is started for the shutter time set according to the photometric data stored in the internal memory of the CPU 117 (step S30).
5)

The CPU 117 measures the shutter time set in accordance with the photometric data, and the image sensor 1
Wait for completion of charge accumulation (exposure) of 5 (step S30
9) and ends the charge accumulation of the image sensor 15 (step S3).
10) Then, the control circuit 119 closes the rear blade group 14b of the shutter device 14 (step S304), thereby ending the exposure by the image sensor 15.

Further, the CPU 117 drives the diaphragm drive unit 4 by the control circuit 119 to drive the diaphragm blade group 5 to the open diaphragm value (step S311), and the main mirror 7 to the unillustrated mirror. The driving means moves to the mirror down position (step S312).

When the set charge accumulation time has elapsed,
The CPU 117 reads out a charge signal from the image sensor 15 after the charge accumulation in the image sensor 15 is completed, and then the CDS /
A / D conversion means 1 via the AGC circuits 102 and 103
04 and 105 convert into a predetermined digital signal, and the memory controller 106 and 108 convert it into the memory 10.
The photographed image data is written in a predetermined area of Nos. 7 and 109 (step S313). When the series of processes is completed, step S129, which is a photographing process routine, is completed.

FIG. 11 shows a detailed flowchart of the calibration operation process in steps S125 and S137 of FIG. The CPU 117
After performing the charge clearing operation of the image sensor 15 (step S401), the front blade group 1 of the shutter device 14 is operated.
In the state where 4a is closed, the above-mentioned unbalance amount calculation circuit 11
6 is instructed to perform the calibration operation, and in order to illuminate the image pickup device 15, a lighting command for the illumination LED devices 17a and 17b for calibration for a predetermined time is output to the driver unit 120 to pick up the image. The imaging screen of the element 15 is illuminated (step S40).
2). The image pickup device 15 is an image by illumination light (FIG. 4)
The charge accumulation of is started (step S403).

When the set predetermined charge accumulation time has elapsed (step S404), the CPU 117 turns off the LED elements 17a and 17b (step S405).
Then, the charge accumulation of the image sensor 15 is completed (step S40).
6) Let it do.

The image pickup device 15 includes the left and right image pickup areas 15b,
The above CDS from CH1 output and CH2 output from 15c
It outputs to the / AGC circuits 102 and 103, processes the output signal as described above, and then inputs the signals to the A / D conversion circuits 104 and 105 to perform a reading process for converting into a digital signal.
(Step S407)

The digital signals (AD-CH1 and AD-CH2) output from the A / D conversion circuits 104 and 105 are
It is input to the unbalance amount calculation circuit 116, and the unbalance amount of the outputs of the left and right imaging regions 15b and 15c of the image sensor 15 is calculated and calculated by the method described above (step S40).
8) The optimum correction amount (correction data) is calculated from the unbalance amount calculated at the same time (step S409), and the calculated balance amount and maximum correction amount (correction data) are stored in the correction data memory 118. Yes (step S41
0).

By performing development processing using the correction data obtained by this calibration processing, the image pickup device 15
It is possible to optimally correct the unbalance amount of the outputs of the left and right imaging regions 15b and 15c, and accurately combine the left and right screens.

The calibration process (step S124) is performed at predetermined time intervals while the release switch (SW1) is pressed, and the calculated unbalance amount and correction amount ( Correction data)
Are stored and stored in the correction data memory 118, and are configured to provide correction data with higher accuracy.

In the above-described embodiment, the first process for starting the calibration process (step S123) is performed.
The release switch (SW1) is used as the switch means of the power switch SW (step S102) shown in FIG.
It doesn't matter.

In this case, the power source SW (step S10
When the 2) is turned on, the operation of the calibration process (step S123) is started, and the second switch means for stopping the calibration process (step S123) is the release switch (SW1) or the release switch (SW1). As SW2), the calibration process (step S123) is repeatedly performed at a predetermined time interval until the release switch (SW1) or the release switch (SW2) is pressed, so that the exposure is performed after the power is turned on. The imbalance amount and the correction amount (correction data) calculated each time until just before the operation are accumulated and stored in the correction data memory 118, and the correction data has higher accuracy.

If the power SW (step S102) is still ON after the exposure operation is completed, the calibration process (step S123) is repeatedly performed at predetermined time intervals, and the latest correction data is obtained each time. It can be calculated.

Further, the first switch means for starting the calibration processing (step S123) of the present embodiment is various photographing condition setting means operated after the power switch SW (step S102) is turned on. , The mode dial switch 128, the single / continuous shooting switch 12
9. Various operation buttons configured by the operation unit 130 may be used.

In this case, the power source SW (step S10
After 2) is turned on, the photographer starts the operation of the calibration process (step S123) by operating the operation members in order to set various shooting conditions as a pre-shooting preparation, and the calibration process (step S123)
The release switch (SW1) or the release switch (SW2) is used as the second switch means for stopping the release switch (SW1), and the release switch (SW1) or the release switch (SW2) is pressed for a predetermined time. The above-mentioned calibration process at intervals (step S1
By repeating operation 23), until just before the exposure operation,
It is possible to reliably calculate the unbalance amount and the correction amount (correction data), accumulate and store more data in the correction data memory 118, and obtain the correction data with higher accuracy.

FIG. 12 is a diagram for explaining the flow of the photographing operation of this embodiment. The description of FIG. 12 is the same as the description given with reference to FIGS.

(Second Embodiment) Another embodiment of the present invention at the time of continuous shooting will be described with reference to the shooting sequence flow of FIGS. 13 to 15. It should be noted that description of portions that perform the same operations as in the first embodiment will be omitted.

The operation until the release switch (SW1) 126 is pressed down by turning on the power source such as battery replacement is the same as that of the first embodiment (FIG. 7), and therefore its description is omitted.

In FIG. 13, if the release switch (SW1) 126 is not pressed (step S5)
21) and returns to step S102 of FIG. If the release switch (SW1) 126 is pressed (step S
521), the CPU 117 performs distance measurement processing to focus the photographing lens 2 on the subject, performs light measurement processing to determine the aperture value and shutter time, and performs distance measurement / light measurement processing (step S522), and Proceeds to S523.
In the photometric processing, the flash is set if necessary. The details of this distance measurement / photometry processing step S522 are shown in FIG.
Is the same as

Further, the CPU 117 performs distance measurement / photometry processing (step S522) in response to the pressing operation of the release switch (SW1) 126, and at the same time, the dark current of the image sensor 15 is closed with the shutter device 14 closed. The noise components such as the above are accumulated for the same time as the main photographing, and the dark capturing process for reading the accumulated noise image signal is performed (step S523), and the process proceeds to step S524.

By performing a correction calculation process using the dark image data captured in this dark capture process,
The captured image data can be corrected with respect to image quality deterioration such as pixel loss due to dark current noise generated by the image sensor 15 or flaws specific to the image sensor 15.

This dark capture processing step S523
Will be described later in detail with reference to FIG. In this way, in response to the pressing operation of the release switch (SW1) 126,
By performing the dark capture processing (step S523) together with the distance measurement / photometry processing (step S522) and then proceeding to step S524, the influence on the release time lag when the release switch (SW2) 127 is pressed in step S524. It is possible to lose it.

If the release switch (SW2) 127 is not pressed (step S524), the release switch (SW1) 126 is released (step S524).
526), the current dark capture processing (step S52)
Repeat 3). Dark capture process (step S
523) makes it possible to accumulate more correction data by repeating the operation at a predetermined time interval, and the reliability of the correction data is improved.
With respect to image quality deterioration such as dark current noise generated by No. 5 and pixel loss due to scratches peculiar to the image sensor 15, the captured image data can be corrected with higher accuracy. If the release switch (SW1) 126 is released (step S
526) and the process returns to step S102 in FIG.

If the release switch (SW2) 127 is pressed (step S524), the CPU 117
Indicates the dark capture processing (step S52) regardless of the processing status of the dark capture processing (step S523).
The cancellation process of 3) (step S525) is performed, and the process proceeds to step S127.

In this way, the release switch (SW
2) The release time lag when the release switch (SW2) 127 is pressed by forcibly canceling the dark capture process (step S523) in response to the pressing operation of 127 and advancing to step S527 and step S529. Can be eliminated.

Next, it is judged whether or not there is an image storage buffer area capable of storing the photographed image data in the memories 107 and 109 (step S527), and the memories 107 and 1
If there is no area for storing new image data in the image storage buffer area of 09, a predetermined warning is displayed by an image or sound using the display / warning unit 133 (step S528), and then step S102 is performed. Return.

If the memories 107 and 109 have an image storage buffer area capable of storing the captured image data (step S527), the CPU 117 reads from the image sensor 15 the image capturing signal which has been captured and accumulated for a predetermined time.
The above-mentioned image processing process is performed to execute the memory 107, 10
A photographing process of writing photographed image data in a predetermined area 9 is executed (step S529). The details of this photographing processing step S529 are the same as those in FIG.

When the photographing processing step S529 is finished, the CPU 117 causes the release switch (SW
2) Before the operation 127, it is determined whether or not the dark capture process (step S523) has been completed at least once (step S530).

As described above, in the electronic still camera 1 of the present embodiment, in order to secure the release time lag, the release switch (SW2) 127 is pressed even during the dark capture process (step S523). As a result, the dark capture process (step S523) is stopped. Therefore, it is determined whether or not the noise component such as the dark current of the image sensor 15 by the dark capturing process (step S523) is accumulated for the same time as the main photographing, and the photographing is performed without reading the accumulated noise image signal. After the detection, the dark capturing process (step S523) is completed at least once, noise components such as dark current of the image sensor 15 for the captured image data are accumulated for the same time as the main image capturing, and the noise image signal is stored. If is read, the process proceeds to step S531.

The state of the single-shot / continuous-shot flag stored in the internal memory of the CPU 117 is judged (step S53).
1) If continuous shooting has been set, the process proceeds to step S532.

If the release switch (SW2) 127 is pressed (step S532), the CPU 117
Is a dark capture process before shooting (step S523)
If so, the dark data is recorded and held (step S533).

It is determined that continuous shooting is performed (step S5).
32), the CPU 117 determines whether or not the shutter control time during exposure of the photographed frame has been exposed for a longer time than a predetermined time (in this embodiment, set to 1/15 second). Perform (step S534).

As a result of the above discrimination, when the CPU 117 controls the shutter at the exposure time longer than 1/15 sec, noise components such as dark current due to the temperature rise of the image pickup device 15 during the exposure. Is different from that before shooting, and the accuracy of the correction data is greatly affected. Therefore, the dark capturing process (step S535) is executed again, and after the dark capturing process (step S523), the capturing operation of the next frame is continued. Therefore, the memories 107 and 109 are checked again (step S127), and the next frame is photographed (step S127).
525) is performed.

Further, when it is determined to be continuous shooting (step S532), if the CPU 117 controls the shutter at a speed faster than 1/15 second, the temperature of the image pickup device 15 rises during exposure. Since there is no effect on the noise component such as dark current due to the above, it is not necessary to execute the dark capturing process (step S535) again, and the dark data of the previous frame is stored and retained (step S523), and the shooting operation of the next frame is performed. In order to continue, the memories 107 and 109 are again used.
Is checked (step S127), and the next frame is photographed (step S525).

As described above, when the dark capture process (step S523) is executed at least once in step S530, and the continuous shooting is set in step S531, the shutter time at the exposure time is changed. In the case of high-speed seconds (short-time exposure: Tv> 1/15), it is not necessary to perform the dark capture process in step S535 for each image frame, so the image process for the next frame (step S529).
Can be executed immediately, and the continuous shooting frame intervals can be made almost constant.

At low speed (long exposure: Tv ≦ 1 /
In the case of 15), by performing the dark capturing process (step S525) for each image frame, it is possible to more accurately capture the noise component such as the dark current generated in the image sensor 15 by performing the long-time exposure. Even if the exposure is performed for a long time, a good image without noise can be obtained.

At this time, the dark capturing process (step S525) is performed for each shooting frame, but the shooting sequence time for one frame is slightly extended. However, continuous shooting frames for shooting at low speed seconds are used. The effect of the speed decrease is greater, and since the shooting is performed at the shutter speed, which requires almost no frame speed, the effect on usability is small.

In this embodiment, during continuous shooting, it is determined whether or not the dark capture processing is performed for each shooting depending on the shutter time. However, during continuous shooting, the dark capture processing is performed depending on the shutter time. A switch for whether or not to perform may be provided and configured to switch.

Further, the shutter time for determining the presence / absence of dark capture processing during continuous shooting may be variable so that the user can arbitrarily set it. If single shot has been set (step S531), the process proceeds to step S540. If the release switch (SW2) 127 is not pressed (step S532), the CPU 1
In step 17, it is determined that the continuous shooting has been stopped, and the flow advances to step S540 to start the development processing of the captured image.

When it is determined that the dark capturing process (step S523) has not been completed at least once (step S530) after completion of the photographing process (step S529), the process proceeds to step S537.

The state of the single-shot / continuous-shot flag stored in the internal memory of the CPU 117 is judged (step S53).
7) If continuous shooting has been set, the process advances to step S538.

If the release switch (SW2) 127 is pressed (step S538), the CPU 117
Indicates that continuous shooting is in progress, and whether the CPU 117 has exposed the shutter control time during exposure of the frames that have already been shot for a longer time than a predetermined time (in this embodiment, set to 1/15 second). Determine whether or not.

When the CPU 117 controls the shutter at the exposure time longer than 1/15 second, the noise component such as dark current may be different from that before the photographing due to the temperature rise of the image pickup device 15 during the exposure. Changes and the influence on the accuracy of the correction data is large. Therefore, the dark capture process (step S535) is executed again, and after the dark capture process (step S523), the photographing operation of the next frame is continued again. Checking the memories 107 and 109 (step S12)
7) is performed, and the next frame is photographed (step S525).

As described above, the execution of the dark capture process (step S523) is not completed in step S530,
Even if the correction data is not stored, step S537
If continuous shooting has been set in step 1 and shooting has been executed, dark capture processing is executed in step S535 for each shooting frame to ensure that the image sensor 1 for the shot image data
Noise components such as dark current of 5 are accumulated for the same time as the main shooting,
The noise image signal that has been stored can be read.

If single shooting has been set (step S537), the flow advances to step S539 to perform dark capture processing, and the image pickup device 15 for picked-up image data.
Noise components such as the dark current of the above are accumulated for the same time as the main photographing, and the noise image signal which has been accumulated is read out, and step S54
The process proceeds to 0 to start the development processing of the captured image.

Also, the release switch (SW2) 12
If 7 is not pressed (step S538), the above C
The PU 117 determines that the continuous shooting has been canceled, and the step S5
Proceed to 39, perform dark capture processing, and step S5
The process proceeds to 40 and the development processing of the captured image is started.

In this way, the photographing process (step S52
Before 9), the noise component such as the dark current of the image sensor 15 for the captured image data by the dark capture process (step S523) is accumulated for the same time as in the main photographing, and the noise image signal after the accumulation cannot be read. Also, after the shooting process (step S538) is completed, regardless of continuous shooting or single shooting,
When the shooting is temporarily stopped, the dark capturing process (step S523) is executed again, noise components such as the dark current of the image sensor 15 are accumulated for the same time as the main photographing, and the noise image signal after the accumulation is read out. Since this is performed, the captured image data can be corrected accurately. Details of the dark capture process (steps S535 and S539) will be described later with reference to FIG.

In the developing process (step S540),
The CPU 117 reads out a noise image signal and uses the noise image signal data to perform image processing on the captured image data. The processed shooting data is the camera DSP1
The data is input to 15, and various development processes including AWB (auto white balance) process, gamma conversion process, and color conversion process are performed (step S540).

Then, the CPU 117 reads the written image data by the camera DSP 115 in a predetermined area of the work memory 121, and performs the image compression processing according to the set mode by the compression / expansion circuit 122 (step S541). , The image data that has been photographed and has been subjected to a series of processing is written in the empty image portion of the image storage buffer area of the work memory 121.

Along with the execution of a series of photographing, the image data stored in the image storage buffer area of the work memory 121 is read out and stored in the non-volatile memory 123 which is a recording medium such as a memory card or a compact flash (R) card. The recording process for writing is started (step S542).

This recording start processing is performed by the work memory 12
Each time new writing of image data that has been photographed and has completed a series of processing is written in the empty image portion of the first image storage buffer area, that image data is executed.

While the image data is being written to the non-volatile memory 123 which is a recording medium, in order to clearly indicate that the writing operation is being performed, for example, the display / warning unit 133 blinks an LED or the like. The recording medium writing operation is displayed.

The development process (step S540) is completed for all the photographed image data written in the predetermined areas of the memories 107 and 109, and the compression process (step S54).
1) When the recording start process (step S542) is performed, the correction data used in the image process (step S540) becomes unnecessary, so the CPU 117 erases the correction data (step S543).

Next, the CPU 117 causes the release switch (SW1) 12 to respond to the shooting of the next frame.
It is determined whether 6 is pressed (step S54).
4). If the release switch (SW1) 126 has been released (step S544), step S
Return to 102.

If the release switch (SW1) 126 has been pressed (step S544), the dark reading process (step S523) is started again for the next frame, and the next frame is taken. . If the release switch (SW1) 126 is released (step S5)
26) and returns to step S102.

FIG. 14 is a detailed flowchart of the dark reading process in steps S523, S535 and S539 of FIG. CPU1 above
After performing the charge clearing operation of the image sensor 15 (step S601), the storage device 17 starts the charge accumulation of the image sensor 15 with the shutter device 15 closed (step S601).
602).

When the set predetermined charge accumulation time has elapsed (step S603), the CPU 117 completes the charge accumulation of the image pickup device 15 (step S60).
4), read out the charge signal from the image sensor 15, and from the A / D converters 104 and 105 through the camera DSP 115,
The dark image data is written in a predetermined area of the CPU 117 (step S605).

By performing development processing using this dark captured data, the captured image data is corrected with respect to dark current noise generated by the image sensor 15 and image quality deterioration such as pixel loss due to scratches peculiar to the image sensor 15. You can When the series of processing is completed, the dark capture processing routine is completed.

The dark capture process is performed at a predetermined time interval while the release switch (SW1) is being pressed, and the dark image data read at each time is the correction data stored in the CPU 117. It is configured to be stored and stored in a memory for use as correction data with higher accuracy.

In the above-described embodiment, the release switch (SW1) is used as the first switch means for starting the dark capture process of this embodiment.
The power supply SW (step S102) shown in FIG. 7 may be used.

In this case, the power source SW (step S10
The release switch (SW1) or the release switch (SW2) is used as the second switch means for starting the operation of the dark capture process and stopping the dark capture process by turning on 2). SW1) or the release switch (SW2) is pressed until the dark capture process is repeated at a predetermined time interval until the dark image is read from the power-on until just before the exposure operation. The data is accumulated / stored in the correction data memory included in the CPU 117, and becomes highly accurate correction data.

If the power SW (step S102) is still ON after the exposure operation is completed, the dark acquisition process is repeatedly performed at predetermined time intervals, and the latest correction data can be calculated each time. it can.

[0241] Further, the first switch means for starting the dark capture processing of the present embodiment is the power switch
The mode dial switch 12 which is various photographing condition setting means to be operated after (step S102) is turned on.
8, the single / continuous shooting switch 129, the operation unit 130
It may be various operation buttons configured by.

In this case, the power source SW (step S10
After 2) is turned on, as a pre-shooting preparation, the photographer operates the operation members to start the operation of the dark capture process and stop the dark capture process in order to set various shooting conditions. The switch means is the release switch (SW1) or the release switch (SW2).
As a result, by repeatedly operating the dark capturing process at a predetermined time interval until the release switch (SW1) or the release switch (SW2) is pressed, the dark reading process is read each time until just before the exposure operation. The dark image data is accumulated and stored in the correction data memory included in the CPU 117, and becomes the correction data with higher accuracy.

FIG. 15 is a diagram for explaining the flow of the photographing operation of this embodiment. The description of FIG. 15 is the same as the description given with reference to FIG. Note that, in the above-described first embodiment, the relationship between the auto-bracketing shooting by the ISO change and the calibration process has been described, but instead of the above-described calibration process, the dark capture described in the second embodiment has been described. The processing may be performed, or both the calibration processing and the dark capture processing may be performed.

In addition, in the second embodiment described above,
Although the relationship between the shutter speed and the dark capture process has been described, the calibration process described in the first embodiment is performed instead of the dark capture process, or both the calibration process and the dark capture process are performed. You may go.

Further, in the first and second embodiments, with respect to the image pickup data to be corrected,
Although the above-described calibration process and dark capture process are performed before image capturing, they may be performed after image capturing or before and after image capturing data to be corrected.

(Other Embodiments of the Present Invention) The image pickup apparatus of the present invention described above is constituted by a CPU of a computer or MPU, RAM, ROM, etc., and is stored in RAM or ROM. It can be realized by running the program.

Therefore, a program that causes a computer to perform the above-mentioned functions may be stored in, for example, a CD-RO.
It can be realized by recording in a recording medium such as M and reading it in a computer. As the recording medium for recording the program, other than the CD-ROM,
Flexible disk, hard disk, magnetic tape,
A magneto-optical disk, a non-volatile memory card, etc. can be used.

Further, not only the functions of the above-described embodiments are realized by executing the supplied program by the computer, but also the OS (operating system) or other application software running the program on the computer. In the case where the functions of the above-described embodiments are realized in cooperation with the above, or all or part of the processing of the supplied program is performed by the function expansion board or function expansion unit of the computer, the functions of the above-described embodiments are realized. However, such a program is also included in the embodiment of the present invention.

Further, in order to use the present invention in a network environment, all or part of the program may be executed by another computer. For example, the screen input process may be performed by a remote terminal computer, and various determinations, log recordings, etc. may be performed by another center computer or the like.

[0250]

As described above, according to the present invention, an optical image of a subject is photoelectrically converted by an image pickup device to generate electronic image data, and the generated electronic image data is recorded on a recording medium. When the above-mentioned subject is photographed using the image pickup device, correction data is calculated for each photographing frame even during continuous photographing during bracket photographing in which the gain of the output signal from the image pickup device is changed. Therefore, during bracket shooting in which the gain (ISO value, etc.) of the output signal from the image sensor is changed for each shooting, correction data is calculated for each shooting frame even during continuous shooting, and the image for each shooting frame is calculated. It is possible to perform the synthesis reliably and accurately.

According to another feature of the present invention, in an image pickup apparatus for photoelectrically converting an optical image of a subject by an image pickup element to generate electronic image data, and recording the generated electronic image data on a recording medium. Therefore, even when performing bracket shooting, which involves changing the gain of the output signal from the image sensor when shooting the subject, when the gain change width is small, the correction data is calculated for each shooting frame. Since it is prohibited to perform this, even during bracket shooting in which the gain (ISO value, etc.) of the output signal from the image sensor is changed for each shooting, if the gain change width is small, Since the correction data calculation operation is not performed, it is possible to perform high-speed continuous shooting without lowering the continuous shooting frame speed.

Further, according to another feature of the present invention, in an image pickup apparatus for photoelectrically converting an optical image of a subject by an image pickup element to generate electronic image data, and recording the generated electronic image data on a recording medium. Even when shooting the above-mentioned subject continuously, when shooting at a low shutter speed that does not affect the continuous shooting frame speed, the dark current noise data is taken for each shooting to correct the shot image. Because I did
Even during continuous shooting, when shooting at low shutter speeds that do not affect continuous shooting frame speed, dark current noise data can be collected for each shooting to correct the captured image, and the effect of dark current noise can be reduced. Regarding the image taken with a large long exposure,
It is possible to obtain a good picked-up image without a feeling of noise with almost no influence on the frame speed.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an electronic camera showing an embodiment of the present invention.

FIG. 2 is a partially enlarged view of the electronic camera in FIG.

FIG. 3 is a perspective view of an image sensor.

FIG. 4 is a diagram showing an illumination state of an image pickup area of an image pickup element.

FIG. 5 is an overall system configuration diagram according to the present embodiment.

FIG. 6 is a diagram showing a specific circuit configuration according to the present embodiment.

FIG. 7 is a flowchart showing an operation of the electronic camera according to the first embodiment.

FIG. 8 is a flowchart showing an operation of the electronic camera according to the first embodiment.

FIG. 9 is a flowchart showing photometry and distance measurement operations of the electronic camera according to the embodiment.

FIG. 10 is a flowchart showing an exposure operation of the electronic camera according to the embodiment.

FIG. 11 is a flowchart showing a calibration operation of the electronic camera according to the first embodiment.

FIG. 12 is an explanatory diagram showing a flow of a shooting operation according to the first embodiment.

FIG. 13 is a flowchart showing an operation of the electronic camera according to the second embodiment.

FIG. 14 is a flowchart showing a dark reading operation of the electronic camera according to the first embodiment.

FIG. 15 is an explanatory diagram showing a flow of a shooting operation according to the first embodiment.

FIG. 16 is a diagram showing a reading principle of the image sensor according to the entire embodiment.

FIG. 17 is a diagram illustrating an overall configuration of a conventional camera system.

[Explanation of symbols]

1 Electronic still camera 2 Shooting lens 3 Imaging lens 4 lens drive 5 diaphragm blades 6 Aperture drive 7 Main mirror 8 Focusing screen 9 penta roof prism 10 Eyepiece device 11 Photometric device 12 sub-mirror 13 Focus detection device 14 Shutter device 14a Leading blade group 15 Image sensor 16 Electric board 17a, 17b LED element 18 Filter member 101 TG / SSG 102, 103 CDS / AGC 104, 105 A / D 106, 108 memory controller 107, 109 memory 110,111 Offset adjustment circuit 112, 113 Gain adjustment circuit 114 image composition circuit 115 camera DSP 116 Unbalance amount calculation circuit 117 Central Processing Unit (CPU) 118 Correction data memory 119 Control circuit 120 DRIVER 126 Release switch (SW1) 127 Release switch (SW2) 128 shooting mode setting 126 Continuous / Single-shot switch 130 Operation unit 131 power switch 133 Display / Warning 140, 141, 142 Average value calculation circuit 143 area selection circuit 144, 145 division circuit 146, 147 Subtraction circuit 148, 149, 150, 1501 correction data calculation circuit 190 photodiode 191 Vertical CCD 192,193 Horizontal CCD 194, 195 amplifier 196, 198 CDS / AGC 197, 199 External adjustment means

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 9/04 H04N 101: 00 // H04N 101: 00 5/91 JF term (reference) 5C022 AA13 AB20 AB37 AB38 AB67 AC03 AC18 AC42 AC52 AC54 AC69 5C024 BX01 CX03 CX32 CX54 CY42 CY50 GY01 GY04 GZ47 HX21 HX29 HX30 HX50 5C053 FA07 FA08 FA27 GA11 HA22 HA33 JA21 KA04 KA24 KA25 LA17 DD22 BB18 DD18

Claims (16)

[Claims] 1. An image pickup apparatus for photoelectrically converting an optical image of a subject by an image pickup device to generate electronic image data, and recording the generated electronic image data on a recording medium. An image pickup apparatus characterized in that correction data is calculated for each image pickup frame even during continuous image pickup during bracket image pickup in which a gain of an output signal from the image pickup element is changed. 2. An image pickup apparatus for photoelectrically converting an optical image of a subject by an image pickup device to generate electronic image data, and recording the generated electronic image data on a recording medium. , Even during bracket shooting with a change in the gain of the output signal from the image sensor,
An image pickup apparatus characterized in that, when the change range of gain is small, calculation of correction data is prohibited for each image frame. 3. An image pickup apparatus for photoelectrically converting an optical image of a subject by an image pickup device to generate electronic image data, and recording the generated electronic image data on a recording medium. However, even when shooting with a low shutter speed that does not easily affect the continuous shooting frame speed, the captured image is corrected while collecting dark current noise data for each shooting. . 4. An image pickup apparatus for recording a still image and / or a moving image generated by picking up an image of a subject on a recording medium, wherein a continuous shooting mode and a continuous shooting mode are set as modes for shooting the subject.
A shooting mode selection unit that has a frame shooting mode and is capable of selectively selecting the continuous shooting mode and the single frame shooting mode, and a first shooting mode for accumulating charges without exposing the subject light. , And a second imaging mode in which the subject light is exposed to accumulate charges, and when the continuous shooting mode is set, before the second imaging mode at the start of continuous shooting or after the continuous shooting ends. The first shooting sequence in which at least one of the first shooting modes is set to the first shooting mode after the second shooting mode, and when the continuous shooting mode is set, before and after the second shooting mode for each shooting of one frame. ,
A second imaging sequence for performing the first imaging mode in at least one of them, and when a predetermined imaging condition is set, imaging for switching between the first imaging sequence and the second imaging sequence An image pickup apparatus comprising a sequence control unit. 5. An image pickup device, wherein an image pickup area is divided into a plurality of pieces, and the divided image pickup data can be read simultaneously through a plurality of outputs, and an image pickup signal processing means for individually processing the outputs from the image pickup means. , An interrelationship discriminating means for discriminating the mutual correlation of data in a predetermined image area with respect to the output from the image pickup signal processing means, and being arranged in the vicinity of the image pickup means, And an image illuminated by the light projected by the light projecting means is imaged by the imaging means, and the imaging result is processed by the imaging signal processing means. In the first imaging mode to be performed, according to the determination result from the mutual relationship determining means,
Correction data calculation means for calculating correction data for correcting the output image signal for each of the image pickup signal processing circuits; correction data storage means for storing and holding the correction data calculated by the correction data calculation means; Image processing means for synthesizing the output image signals captured in the second image capturing mode from each of the processing circuits corrected on the basis of the above to generate one captured image. Item 4. The image pickup device according to item 4. 6. In the first image pickup mode, the imaged image data is dark current noise data of the image pickup means, and in the second image pickup mode, the imaged image data is taken by the image pickup means. The image pickup apparatus according to claim 4, wherein the image pickup image data is taken image data. 7. Bracket photographing means for photographing a plurality of frames by changing a value of at least one processing parameter information by image processing changing means for each photographing frame, and the predetermined photographing condition is bracket photographing. The imaging device according to claim 4 or 5, characterized in that. 8. The value of the processing parameter information is at least one of sensitivity change, color temperature correction, saturation change, and black level change.
The imaging device according to. 9. The predetermined photographing condition is shutter speed, and when the shutter speed is higher than the predetermined shutter speed,
While switching to the first shooting sequence, if the shutter speed is set to a slower shutter speed than the predetermined shutter speed, the second shutter speed is set.
The imaging apparatus according to claim 7, wherein the imaging sequence is switched to the imaging sequence. 10. When the value of the processing parameter information is set to a predetermined value or less during bracket shooting by the bracket shooting unit, the first shooting sequence and the second shooting sequence by the shooting sequence control unit. 9. The image pickup apparatus according to claim 7, further comprising a prohibition unit that prohibits switching of. 11. An image pickup method for photoelectrically converting an optical image of a subject by an image pickup device to generate electronic image data, and recording the generated electronic image data on a recording medium. An image pickup method characterized in that, during bracket shooting accompanied by a change in gain of an output signal from the image pickup device, correction data is calculated for each shooting frame even during continuous shooting. 12. An imaging method for photoelectrically converting an optical image of a subject by an image sensor to generate electronic image data, and recording the generated electronic image data in a recording medium, the method comprising: , Even during bracket shooting with a change in the gain of the output signal from the image sensor,
An imaging method characterized in that when the change range of the gain is small, calculation of correction data is prohibited for each image frame. 13. An imaging method for photoelectrically converting an optical image of a subject with an image pickup device to generate electronic image data, and recording the generated electronic image data on a recording medium. However, even when shooting with a slow shutter speed that does not easily affect the continuous shooting frame speed, the captured image is corrected while collecting dark current noise data for each shooting. . 14. A computer-readable storage medium having recorded therein a program for causing a computer to execute the functions of the respective means according to any one of claims 4 to 10. 15. A computer-readable storage medium having recorded thereon a program for causing a computer to execute each method according to any one of claims 11 to 13. 16. A computer program for causing a computer to execute each method according to any one of claims 11 to 13.