JPH11196321A - Image pickup device and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save power and enhance the image quality according to a photo graphic mode by changing the speed of reading image signals between the cases when plural signals are composited and when they are not. SOLUTION: Accumulated charge of an image pickup device 131 is read at a low speed clock fL when a main switch 150 and a photography preparation switch 151 are on, an image is shown on an indicator 141 before photographing for framing confirmation and also a preparation operation of photography is performed. Next, a photographic switch 152 is turned on and the state of a photographic mode selection switch 13 is discriminated. Accumulated charge of the device 131 is read at the clock fL at the time of normal photographing made that does not shift an image, undergoes signal processing and is recorded and preserved. Also, the accumulated charge of the device 131 is read, by performing image shifting, at a high speed clock fH at the time of a high definition mode that performs pixel shifting, undergoes signal processing and image synthetic processing and is recording and preserved. Thus, it is possible to save power according to a photographic mode and to produce a high definition image that reduces the effects of blurring and object blurring.

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 and a method therefor, for example, an image pickup apparatus for obtaining one set of high-definition images from a plurality of sets of image signals and a method thereof.

[0002]

2. Description of the Related Art Conventionally, a plurality of sets of image signals have been obtained while slightly changing the relative position between a subject image formed by an imaging optical system and an image pickup device for photoelectrically converting the image. An imaging apparatus using a so-called pixel shifting technique for obtaining a high-definition image by combining signals by a predetermined method has already been proposed.

[0003]

However, the pixel shifting technique in the above-mentioned conventional image pickup apparatus, like the multiple exposure of the still camera, increases the interval between the acquisition time of the first image signal and the time of the last image signal. If camera shake or subject shake occurs during that time, the image quality deteriorates, and high definition by shifting pixels cannot be expected.

Therefore, as a method for resolving this drawback, (1) as disclosed in Japanese Patent Application Laid-Open No. 7-240932, a camera shake correction mechanism is incorporated in a photographic optical system to reduce image shake due to camera shake.

(2) By shortening the image signal reading time of the image sensor, the time required for photographing is shortened, and the occurrence of image shake due to camera shake and object shake is prevented.

(3) As disclosed in JP-A-6-225317, a plurality of sets of image signals read from an image sensor are temporarily stored in a frame memory sequentially, and the image signals are compressed and recorded on a magnetic medium. By performing a process that requires a long time, such as, after photographing, the time required for photographing is reduced, and image blur due to camera shake and subject shake is prevented. And so on.

However, the above method has the following disadvantages.

In the case of using the camera shake correction mechanism of (1), since the photographing time is not shortened, it is not possible to prevent the image shake due to the movement of the object, that is, the object shake.

On the other hand, in the measure (2), the power consumption of the image pickup device is increased and the battery life is shortened as the image signal read clock of the image pickup device is accelerated. The thermal noise of the signal increases, and the noise of the image increases.

Further, the measure (3) requires a large-capacity and expensive frame memory, which leads to an increase in the price of the image pickup apparatus. Therefore, in the above-mentioned Japanese Patent Application Laid-Open No. 6-225317, the increase in price is used to increase the added value of a product by using the frame memory as a buffer memory for continuous photographing. However, in the pixel shift shooting and the continuous shooting, the image intended by the photographer cannot be obtained unless the shooting operation control such as the shooting interval is changed, but the above-mentioned Japanese Patent Laid-Open No. 6-225317 does not disclose such control. A desired photographing effect cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and an object of the present invention is to provide an imaging apparatus and a method thereof capable of achieving both power saving and high image quality according to a shooting mode.

For example, there is provided an image pickup apparatus and a method for performing readout control of an image pickup element suitable for each of a case where normal shooting is performed with pixel shift shooting prohibited and a case where pixel shift shooting is performed. For the purpose.

Another object of the present invention is to provide an image pickup apparatus and a method thereof that perform readout control of an image pickup element suitable for each of normal photographing and pixel shift photographing with a simple configuration.

It is another object of the present invention to provide an imaging apparatus and a method for obtaining high-definition images by reducing image blurring during pixel-shifted imaging while saving power during normal shooting.

Another object of the present invention is to provide an image pickup apparatus and a method thereof, which make it possible to obtain an image according to a photographing intention by making an image pickup element control method at the time of pixel shift photographing variable.

Further, for example, it is an object of the present invention to provide an image pickup apparatus having a photographing mode for obtaining a high-quality image with little noise or the like and a photographing mode for obtaining a high-definition image with little image blur in a pixel shift photographing, and a method therefor. Aim.

Further, for example, in a pixel shift photographing, an image pickup apparatus and a photographing apparatus in which a photographer can select a photographing mode for obtaining a high-quality image with little noise or the like and a photographing mode for obtaining a high-definition image with little image blur. The purpose is to provide a method.

It is another object of the present invention to provide an image pickup apparatus having a photographing mode for photographing a still object with high definition and a photographing mode for continuously photographing a moving object and a method thereof.

It is another object of the present invention to provide an image pickup apparatus and method capable of sufficiently expressing a dynamic effect of a subject between captured images during continuous shooting.

It is another object of the present invention to provide an image pickup apparatus and a method thereof that enable a photographer to select a dynamic effect of a subject during continuous photographing.

It is another object of the present invention to provide an image pickup apparatus and a method thereof which enable a photographer to select the number of continuous photographing frames during continuous photographing.

Also, for example, an image pickup apparatus for performing read control of an image pickup element suitable for each case when performing normal photographing while prohibiting high-quality photographing by multiple exposures and when performing high-quality photographing. The purpose is to provide that method.

[0023]

As one means for achieving the above object, the image pickup apparatus of the present invention has the following arrangement.

That is, an image forming means for forming an object image,
Photographing means for subjecting the formed subject image to photoelectric conversion to generate an image signal, reading means for reading the photoelectrically converted image signal from the photographing means, and holding the read image signal A plurality of image signals based on one subject image obtained by the photographing unit, and held by the holding unit to combine the plurality of image signals. Is characterized in that the reading speed of the image signal is changed depending on whether or not the combining is performed by the combining means.

Further, there is provided moving means for moving the image forming means to change the image forming position of the subject image, and the synthesizing means is adapted to move the image forming position of the subject image by the moving means. A plurality of image signals having different image forming positions are obtained by the photographing means, held in the holding means, and the plurality of image signals are synthesized.

Further, there is provided an exposure adjusting means for adjusting an exposure level of the subject image, and the synthesizing means changes the exposure level of the subject image while changing the exposure level of the subject image by the exposure adjusting means. A plurality of image signals are obtained and held in the holding unit, and the plurality of image signals are combined.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below in detail with reference to the drawings.

<First Embodiment> An imaging device according to the present embodiment will be described with reference to FIGS.

FIG. 1 is a block diagram showing the configuration of the image pickup apparatus according to the present embodiment. In FIG. 1, reference numeral 101 denotes a camera body having a function of forming a subject image and capturing the image. A power supply 102 supplies power to each circuit and actuator in the camera body 101.

Reference numeral 103 denotes a microcomputer (hereinafter abbreviated as a microcomputer), which is a one-chip microcomputer having a ROM, a RAM, an A / D, and a D / A conversion function. Microcomputer 103
Are automatic exposure control (AE) and automatic focus adjustment (AF) according to a camera sequence program stored in the ROM.
And a series of operations related to image signal acquisition such as pixel shift control, imaging, image recording, and the like. For this purpose, the microcomputer 103 controls the operation of each circuit and actuator in the camera body 101.

An oscillator 104 such as a quartz oscillator supplies a clock to the microcomputer 103. Then the microcomputer 103
Generates a reference clock obtained by multiplying the clock and uses it as a reference signal for various controls, and also supplies the reference clock to a timing generator for driving an image pickup device described later.

Reference numerals 111 to 115 denote imaging optical systems for forming a subject image, 111 denotes a focusing lens for adjusting the focus by moving back and forth in the optical axis direction, and 112 denotes a zooming lens for changing the magnification by moving back and forth in the optical axis direction. 1
Reference numeral 13 denotes an aperture for adjusting the amount of light to the image sensor. 114
Performs a predetermined imaging action together with the lenses 111 and 112, and moves in a plane perpendicular to the optical axis to change the relative position between the image sensor and the subject image on the imaging plane. Lens. Reference numeral 115 denotes a low-pass filter for limiting the resolution limit of the subject image to a Nyquist frequency or less determined by the pixel interval of the image sensor, and uses the birefringence of a quartz plate.

Reference numeral 121 denotes a focus actuator which adjusts the focus by moving the focusing lens 111 in the optical axis direction, and the focus encoder 122 detects information corresponding to the position of the lens 111, that is, the subject distance, and sends the information to the microcomputer 103. . A zoom actuator 123 performs zooming by moving the focusing lens 111 and the zooming lens 112 in the optical axis direction by a zoom mechanism (not shown), and the zoom information is detected by the zoom encoder 124 and transmitted to the microcomputer 103. Reference numeral 125 denotes a diaphragm actuator for driving the diaphragm 113. 126 is a shake detection sensor such as a vibration gyro,
Two identical sensors are arranged orthogonally in order to detect the camera shake in the vertical (pitch) direction and the horizontal (yaw) direction. Then, the camera shake detection signal is transmitted to the microcomputer 103, and the microcomputer 103 generates a camera shake correction signal from the signal. Reference numeral 127 denotes an image shift actuator which drives and controls the image shift lens 114 in a plane perpendicular to the optical axis in accordance with the camera shake correction signal, and controls the relative position between the subject image and the image sensor to reduce image shake due to camera shake. In addition to the correction, it also has a pixel shifting function described later.

Reference numeral 131 denotes an image sensor, which is a photoelectric conversion means constituted by a CCD or the like, which photoelectrically converts a subject image formed by the image pickup optical system and outputs an image signal. 132 is a pre-processing circuit, which includes CDS (correlated double sampling), AGC
(Auto gain control) This circuit includes a circuit and the like, and controls the image sensor to output an accurate image signal. 13
An A / D converter 3 converts an analog image signal output from the preprocessing circuit 132 into a digital signal.
Reference numeral 134 denotes an image signal processing IC that performs γ correction, AWB (auto white balance), and the like on the digitized image signal, and performs image density non-linearity caused by characteristics of the image sensor 131 and light source caused by a light source. Of the image color to be corrected. Reference numeral 135 denotes a frame memory, which is a buffer memory for temporarily storing a plurality of sets of image signals at the time of pixel shift shooting described later. 136 is a timing generator,
On the basis of the reference clock transmitted from the microcomputer 103, a clock signal for controlling the image signal reading of the image sensor 131 is transmitted, and the operation timing of each of the elements 131 to 135 is controlled.

Reference numeral 141 denotes a display constituted by a liquid crystal display or the like, which displays an image obtained by the image pickup device 131, and also displays an operation state of the camera, photographing conditions, and the like. 1
An LCD driver 42 controls the display of the display 141 based on a display command from the microcomputer 103. 14
A compression circuit 3 compresses the obtained image signal to reduce the file size of the image. Reference numeral 144 denotes a recording medium for recording and storing the compressed image signal, and a semiconductor memory, a magnetic disk, an optical disk, or the like is used.

Reference numeral 145 denotes a connector for connecting to an external device such as a desktop computer.
4 is used to transmit the contents of the camera to the outside, or to control the camera body 101 by a signal from an external device. Reference numeral 150 denotes a main switch. When the switch is turned on, the microcomputer 103 permits execution of a predetermined program relating to photographing. Switches 151 (SW1) and 152 (SW2) are linked to the release button of the camera, and are turned on when the first and second strokes of the release button are depressed, respectively. A shooting mode (image quality mode) selection switch 153 is used to set whether or not to perform pixel shift shooting. Reference numeral 154 denotes an up / down switch, which is a switch for setting a change in photographing conditions and the like.

FIG. 2 is a diagram simply showing the structure of the image sensor 131 shown in FIG.

On the light receiving surface of the image sensor 131, m1 × n1 photocells 161 are formed. Reference numeral 162 denotes a vertical transfer CCD for transferring charges generated in proportion to the luminance of the subject image projected on the photocell 161 in the direction of arrow TRV in the figure. A horizontal transfer CCD 163 outputs charges discharged from the vertical transfer CCD 162 to the outside via an image signal output terminal 165. A timing signal input terminal 164 receives a control clock from the timing generator 136 and controls charge accumulation and transfer driving by the photocell 161, the vertical transfer CCD 162, and the horizontal transfer CCD 163.

FIG. 3 is a diagram showing a display form of the display 141. The display is a liquid crystal display panel comprising m 2 × n 2 liquid crystal display cells, and displays a subject image 171 at the time of preparation for photographing or after photographing. The selected shooting mode (image quality mode) is displayed at the lower right of the display screen. Display 1
Reference numeral 72 denotes a normal mode, that is, a normal photographing mode in which photographing with shifted pixels is not performed. On the other hand, a display 173 indicates a high-definition mode, that is, a high-definition shooting mode by shifting pixels. When the photographer operates the photographing mode selection switch 153 in FIG. 1, the mode displays 172 and 173 are displayed on the display 141. The photographing mode can be switched by operating the up / down switch 154, and the result is displayed based on whether or not the triangle display portion is filled. FIG. 3 shows that the latter pixel shift mode is selected.

FIG. 4 is a view for explaining the positional relationship between the subject image and the image sensor at the time of pixel shift shooting. Reference numeral 161 denotes a photocell on the image sensor 131 described with reference to FIG. 3, and a mosaic color filter is formed on the upper layer of each photocell 161 on a chip. In the figure, G indicates green, R indicates red, and B indicates blue filters. This filter arrangement is a general arrangement method called a Bayer arrangement in which G checkered R / B lines are sequentially arranged.

IM1 to IM4 are points indicating the relative positions of the subject image at the time of the pixel shift shooting. It is assumed that a point of the subject image is located at IM1 at the time of acquiring (exposure) the first set of images at the time of pixel shift shooting. After the image of the first set is acquired, the image shift lens 114 in FIG.
Move to M2 to acquire a second set of images. Similarly, the subject image is moved to IM3 and IM4 to acquire the third and fourth sets of images, and the pixel shift shooting is completed.

FIG. 5 is a diagram showing a newly generated high-definition image signal array obtained by synthesizing a plurality of sets (four in this embodiment) of image signals obtained by pixel shift shooting. By interpolating and generating signal missing portions of the plurality of sets of image signals using an appropriate interpolation filter, the pixel pitch in both the horizontal and vertical directions is half the pixel pitch of the original image sensor, and RGB is used.
An image signal having color information of three primary colors is obtained. That is, a high-definition image having an information amount four times as large as the original image size can be obtained by the pixel shift photographing. Since the above-described pixel shifting and image synthesizing methods are disclosed in Japanese Patent Application Laid-Open No. 6-225317, a detailed description thereof will be omitted.

FIG. 6 is a timing chart of drive control of the image sensor 131 at the time of photographing. The upper part (11 to 15) shows normal photographing without pixel shift, and the lower part (21 to 27) shows control at pixel shift photographing. Show. First, the timing chart at the time of normal shooting in the upper stage will be described.

At time t11, a shooting preparation switch (SW)
1) When 151 is turned on, the camera executes various shooting preparation operations such as photometry and focus adjustment. Subsequently, when the photographing switch (SW2) 152 is turned on at time t12, the operation shifts to a photographing operation, and a charge accumulation start timing pulse is input at time t13. Then, the electric charge is accumulated in each photocell 161 of the image sensor 131. At time t14, the electric charge accumulation ends, and the transfer of the accumulated electric charge starts immediately.
At this time, the first low frequency is applied as the clock frequency for the charge transfer supplied to the image sensor 131, so that it takes 1/30 seconds for the charge transfer of all pixels, and the charge transfer at time t15. Ends.

Next, a timing chart at the time of lower pixel shift photographing will be described.

At time t21, the photographing preparation switch (SW)
1) When 151 is turned on, the camera executes various shooting preparation operations such as photometry and focus adjustment. Subsequently, when the photographing switch (SW2) 152 is turned on at a time t22, the operation shifts to a photographing operation. At a time t23, a charge accumulation start timing pulse of the first group of images is input. Then, the electric charge is accumulated in each photocell 161 of the image sensor 131, the electric charge accumulation ends at time t24, and the transfer of the accumulated electric charge starts immediately. At this time, a second frequency having a frequency higher than the first frequency, specifically, twice as high as the first frequency is applied as a clock frequency for charge transfer supplied to the image sensor 131. Therefore, the time required for the charge transfer of all the pixels is 1/60 second, which is half the time required for the normal photographing, and the time t26
, The charge transfer ends.

On the other hand, at time t24 when the charge accumulation is completed, a horizontal pixel shift waveform is generated. The pixel shift waveform is added to a shake detection output of a shake detection sensor 126 that detects a shake in the horizontal direction, and the image shift lens 114 is driven based on the added signal. Therefore, the image blur due to the camera shake is removed from the subject image, and a predetermined amount of horizontal movement with respect to the image sensor 131, that is, a pixel shifting operation is performed. Then, when the charge accumulation start timing pulse of the second set of images is input at time t25, the charge accumulation of the second set of images starts, and at time t27, the charge accumulation ends, and the transfer of the accumulated charge starts. Is done. Then, at time t27, a new horizontal and vertical pixel shift waveform is generated, and the pixel shift operation for the third set of images is performed.

By repeating the above operation, the third and fourth sets of images are obtained, and the pixel shift shooting is completed.

According to the above control, the charge transfer time of one set of image signals is reduced to half in the pixel shift shooting as compared with the normal shooting. For this reason, the total time required for photographing is approximately doubled despite performing four photographings, and the effects of camera shake and subject shake during photographing are reduced.

FIG. 7 is a table for comparing the charge transfer clock frequency of the image pickup device, the readout (charge transfer) time of a set of images, and the final image size in the two types of photographing modes. As described with reference to FIG. 6, the read (charge transfer) time for one set of images during the pixel shift shooting is half that of the normal shooting, so that the influence of camera shake and subject shake due to multiple exposures during the pixel shift shooting is reduced. Can be suppressed.
On the other hand, since reading is not speeded up during normal photographing, useless increase in power consumption and deterioration in image quality (decrease in S / N ratio of an image signal) due to dark current due to heat generation of the image sensor 131 can be prevented.

FIG. 8 shows a camera body 101 according to this embodiment.
5 is a flowchart showing control of the microcomputer 103 in the first embodiment. Hereinafter, the control of the microcomputer 103 will be described using the flowchart of FIG. 8 with reference to FIGS. 1 to 7 described above.

Main switch 15 of camera body 101
When 0 is turned on, the microcomputer 103 exits the sleep state and proceeds from step S101 to step S102.
In step S102, the state of each of the switches 151 to 154 in the camera body 101 is detected.

In step S103, the photographing preparation switch (SW) which is turned on when the release button is pressed in the first stage.
1) The state of 151 is determined, and when the switch 151 is off, the process returns to step S102. The switch 151
Is turned on, the process proceeds to step S104, and the following shooting preparation operation is performed.

In step S104, the shake detection sensor 1
The power supply to the camera body 101 is performed, and the detection of camera shake occurring in the camera body 101 is started. Then, the microcomputer 103 calculates the driving amount of the image shift lens 114 based on the signal, drives the lens 114 to perform camera shake correction, and stabilizes the subject image. Next, in step S105, the image sensor 1
The frequency of the clock generated by the timing generator 136 for controlling the charge transfer of the clock 31 is set to the first low frequency fL (= 12 MHz).

In step S106, the image sensor 13
1 to obtain an image signal. Specifically, the charge storage time of the photocell 161 is controlled, and then the charge is transferred at the first frequency fL and sent to the preprocessing circuit 132. Subsequently, in step S107, the above-described step S10
The image signal acquired in step 6 is processed. Specifically, A
The A / D converter 133 performs A / D conversion of the image signal, and the image signal processing IC 134 performs processing such as white balance and γ correction. In step S108, the image signal processed in step S107 is stored in the frame memory 13
5 (the frame memory 1 in FIG. 1).
).

In step S109, the frame memory 1
The image signal stored in 35 is read to calculate the subject luminance information. If the aperture value of the aperture 155 is inappropriate, the aperture value is re-controlled. Next, in step S110, the image signal stored in the frame memory 135 is read, high-frequency components are extracted, the focus state of the subject is detected, and the focusing lens 111 is driven to perform focusing. In step S111, a thinning process is performed to match the number of pixels of the image signal stored in the frame memory 135 with the number of display pixels of the display 141, and the processed image is displayed on the display 141.

In step S112, the photographing switch (SW)
2) The state of 152 is determined, and if the switch 152 is off, the process returns to step S102, and the operations of steps S102 to S110, that is, the shooting preparation operation, are repeatedly executed. If it is determined in step S112 that the photographing switch 152 is ON, it is determined that a release operation has been performed, and the process proceeds to step S121.

In step S121, the state of the photographing mode (image quality mode) selection switch 153 is determined to determine whether the mode is the normal mode or the high definition mode. If it is determined that the mode is not the high definition mode, that is, the mode is the normal mode, the process proceeds to step S122.

In steps S122 to S125, a photographing process is performed in the same manner as in steps S105 to S108, and the photographed image signal is stored in the frame memory 1.
The image data is stored in the 35th image storage area of the first set (corresponding to the frame memory 1 in FIG. 1).

Subsequently, in step S126, the compression circuit 1
43, the image signal in the frame memory 135 is compressed. In step S127, the compressed image is
Record and save in 44. In step S128, similar to step S111, a thinning process is performed to match the number of pixels of the captured image signal stored in the frame memory 135 with the number of display pixels of the display 141, and the processed image is displayed on the display 141. To be displayed. Thus, the shooting in the normal mode ends, and the process returns to step S102.

Next, the photographing process in the high definition mode will be described.

If it is determined in step S121 that the shooting mode is the high definition mode, the process jumps to step S131.

In step S131, the states of the focus encoder 122 and the zoom encoder 124 are detected to detect the focus and zoom states. Then, in step S132, a pixel shift waveform is set based on the optical information detected in step S131. This is because, when the pixel shift control is performed using a part of the imaging optical system in which the imaging condition changes due to zooming or the like as in the present embodiment,
Image shift lens 114 according to the optical state of the photographing optical system
Changes the subject image shift amount per unit movement amount. Therefore, it is necessary to perform a pixel shift drive amount normalization operation for aligning the subject image shift amount with the pixel pitch of the image sensor 131. Therefore, in step S132, a normalization operation according to the optical state is performed, and 26 and 2 in FIG.
The pixel shift waveform indicated by 7 is set.

In step S133, the timing generator 13 controls the charge transfer of the image sensor 131.
6 is set to a second frequency fH (= 24 MHz) higher than the first frequency fL. In step S134, the image sensor 131 is driven to acquire an image signal. Specifically, the charge storage time of the photocell 161 is controlled, and the charge is subsequently transferred to the second frequency fH.
, And sends it to the preprocessing circuit 132. In step S135, the image signal acquired in step S134 is processed as in step S124. In step S136, the image signal processed in step S135 is stored in the frame memory 13 as in step S125.
5 (the frame memory 1 in FIG. 1).
).

Next, in step S137, the image shift lens 114 is driven according to the pixel shift waveforms 26 and 27 in FIG. 6 to shift the pixels.

In step S138, it is determined whether or not the pixel shift shooting has been completed. If not, the flow returns to step S134. Then, steps S134 to S137 are repeatedly executed to obtain the second to fourth sets of images while performing the pixel shift driving shown in FIG. 4, and the obtained images are stored in the frame memories 2 to 3 in the frame memory 135. 4 are sequentially stored. On the other hand, if it is determined in step S138 that the pixel shift shooting has been completed, the process proceeds to step S139.

In step S139, a plurality of sets of image signals obtained by the pixel shift photographing are combined using a predetermined interpolation algorithm to obtain a high definition image signal as shown in FIG.

Subsequently, the flow jumps to step S126, where image compression, recording and storage and display are performed in steps S126 to S128 in the same manner as in the normal photographing described above.
The shooting of the high-definition image of the piece ends, and the process returns to step S102.

The processing shown in the flowchart of FIG. 8 will be outlined again below.

When the photographer turns on the main switch 150 and the photographing preparation switch (SW1) 151, the electric charges accumulated in the image sensor 131 are read out at the low-speed clock fL, and the image before photographing for framing confirmation is displayed on the display. 1
In addition to being displayed on 41, shooting preparation operations such as camera shake correction, photometry / aperture control, and focus adjustment are performed. Subsequently, when the shooting switch (SW2) 152 is turned on, the state of the shooting mode selection switch 153 is determined. Then, in the case of the normal shooting mode in which no pixel shift is performed,
The charges accumulated in the image sensor 131 are read out by the low-speed clock fL, subjected to image signal processing, and recorded and stored.
On the other hand, when the high-definition mode in which the pixel is shifted is selected, the electric charges accumulated in the image sensor 131 are shifted while the image is shifted for the pixel shift.
H, read out, subjected to image signal processing and image synthesis processing, and recorded and stored.

As described above, according to the present embodiment,
During normal photographing without pixel shifting, the image sensor is driven by a low-speed clock to save power, suppress heat generation of the image sensor, and prevent an increase in image noise. On the other hand, at the time of pixel-shift shooting, a high-definition image in which the influence of camera shake and subject shake is reduced by driving the image sensor with a high-speed clock can be obtained. Therefore, it is possible to achieve both power saving and high image quality according to the shooting mode.

In other words, by switching the reading speed of the photoelectric conversion signal of the image sensor between the time when the pixel shift shooting is prohibited and the time when the shooting is permitted, unnecessary power consumption can be prevented and the photographer's intention can be reduced. An appropriate high-definition image can be obtained.

Further, since the frequency of the charge reading clock applied to the image pickup device is switched and the reading speed of the photoelectric conversion signal is switched according to the photographing mode, a high-definition image according to the photographer's intention can be obtained with a simple configuration. be able to.

Further, at the time of pixel shift shooting, a high-speed clock is applied to the charge transfer section of the image sensor, and the image signal is read out at a high speed, so that the shooting time at the time of pixel shift shooting is shortened, and camera shake and subject shake are reduced. High definition images can be obtained.

<Second Embodiment> Hereinafter, a second embodiment according to the present invention will be described.
An embodiment will be described.

In the above-described first embodiment, the configuration has been described in which the image pickup device is always driven at a high speed at the time of pixel-shifted photographing to reduce the influence of camera shake and subject shake. However, when the image pickup device is driven at high speed, noise to the charges increases during the charge transfer, and although the definition of the image can be improved, the S / N ratio of the image, that is, the dynamic range in the luminance region slightly decreases. There is also a problem unfavorable for high quality.

Therefore, in the second embodiment, a mode in which the image pickup device is driven at a high speed or a mode in which the image sensor is driven at a low speed at the time of pixel-shifted photographing can be selected, and the photographer can reduce camera shake, subject shake and image quality. It is possible to select whether to give priority.

Hereinafter, the imaging apparatus according to the second embodiment will be described with reference to FIGS.

FIG. 9 is a block diagram showing the configuration of the imaging apparatus according to the second embodiment. The image pickup apparatus according to the second embodiment is different from the image pickup apparatus shown in FIG. 1 in the above-described first embodiment in that a switch group 150 to 154 and an image stabilization (hereinafter abbreviated as IS) selection switch 255 are provided. The only difference is that the control of the microcomputer 203 and the display form of the display 241 change accordingly. Since other configurations are the same as those of the first embodiment, the same members are denoted by the same reference numerals as in FIG. 1 and the description is omitted.

In FIG. 9, reference numeral 203 denotes a microcomputer which controls the operation of the camera body 201 in accordance with a flowchart described later. A display 241 displays a subject image and shooting conditions. 251 is a shake correction selection (IS) switch 2
At 55, the shake detection sensor 126 and the image shift lens 11
A switch for selecting whether or not to execute camera shake correction by driving No. 4.

FIG. 10 is a diagram showing a display form of the display 241. The display 241 has m2 × as in the first embodiment.
a liquid crystal display panel comprising n2 liquid crystal display cells,
A subject image 271 at the time of preparation for shooting or after shooting is displayed. The selected camera shake correction mode and shooting mode (image quality mode) are displayed at the lower right of the display screen. Display 27
Reference numeral 2 denotes a camera shake correction OFF mode, and reference numeral 273 denotes a camera shake correction ON mode. When the IS switch 255 shown in FIG. 9 is operated by the photographer, the mode displays 272 and 273 are displayed on the display 241. And up-down switch 15
The camera shake correction mode can be switched by the operation of step 4, and the result is displayed based on whether or not the triangle display section is filled. FIG. 10 shows that the latter camera shake correction on mode is selected.

A display 274 indicates a normal mode, that is, a normal shooting mode in which pixel-shifted shooting is not performed, and a display 275 indicates a high-definition mode, that is, a high-definition shooting mode in which pixel shifting is performed. When the photographer operates the photographing mode selection switch 153 in FIG. 9, the mode displays 274 and 275 are displayed on the display 24.
1 is displayed. The photographing mode can be switched by operating the up / down switch 154, and the result is displayed based on whether or not the triangle display portion is filled. FIG.
A value of 0 indicates that the latter pixel shift mode is selected.

FIG. 11 shows the charge transfer clock frequency of the image pickup device, the readout (charge transfer) time of one set of images, and the final image size in four types of photographing modes based on a combination of the above-mentioned camera shake correction mode and image quality mode. It is a table to be compared. Since high-speed driving of the image sensor is not required during normal photographing without pixel shift, the first low frequency is used as the clock frequency regardless of whether camera shake correction is on or off. Also, when camera shake correction is selected in the pixel shift shooting, shooting of a still subject using a tripod is assumed, and thus the possibility of occurrence of camera shake and subject shake is low. Therefore, also in this case, the first low frequency is applied as the clock frequency, and the photographing operation conditions suitable for acquiring a high-quality image with little noise are set.

On the other hand, when the camera shake correction ON is selected in the pixel shift shooting, it is assumed that the camera is supported by the hand-held camera, and therefore, there is a high possibility that camera shake and subject shake will occur. Therefore, in this case, the clock frequency is set to the second frequency higher than the first frequency, and the photographing operation conditions are set to reduce the influence of camera shake and subject shake.

FIG. 12 shows a camera body 2 according to the second embodiment.
11 is a flowchart illustrating control of the microcomputer 203 in the first embodiment.

FIG. 12 shows a camera body 2 according to the second embodiment.
11 is a flowchart illustrating control of the microcomputer 203 in the first embodiment. Hereinafter, the control of the microcomputer 203 will be described using the flowchart of FIG. 12 with reference to FIGS. 9 to 11 described above.

The main switch 15 of the camera body 201
When 0 is turned on, the microcomputer 203 exits the sleep state and proceeds from step S201 to step S202.
In step S202, the state of each of the switches 151 to 154 and 255 in the camera body 201 is detected. In step S203, the photographing preparation switch (SW1) 1 which is turned on by pressing the release button in the first stage
The state of 51 is determined, and when the switch 151 is off, the process returns to step S202. When the switch 151 is turned on, the process proceeds to step S204, and the following photographing preparation operation is performed.

In step S204, it is determined whether or not the camera shake correction function is selected. If the camera shake correction is selected, the flow advances to step S205. In step S205, power is supplied to the shake detection sensor 126, and detection of camera shake occurring in the camera body 201 is started. Then, the microcomputer 203 makes the image shift lens 114 based on the signal.
Is calculated, and the lens 114 is driven to perform camera shake correction to stabilize the subject image. On the other hand, when the camera shake correction is not selected, step S205 is not executed, and the process jumps from step S204 to step S206.

In step S206, the timing generator 13 controls the charge transfer of the image sensor 131.
6 is the first low frequency fL
(= 12 MHz). Step S207 is the first
Steps S106 to S shown in FIG. 8 in the embodiment
108, the charge accumulation of the image sensor 131 and the image sensor 131 based on the first frequency fL.
, The processing of the image signal by the preprocessing circuit 132, and the processing of storing the processed image signal in the image storage area of the first set of the frame memory 135 (corresponding to the frame memory 1 in FIG. 9).

Subsequently, in step S208, the image signal stored in the frame memory 135 is read out, the subject luminance information is calculated, and if the aperture value of the aperture 155 is inappropriate, the aperture value is re-controlled. In step S209, the image signal stored in the frame memory 135 is read, the high frequency component is extracted, the focus state of the subject is detected, and the focusing lens 111 is driven to perform focusing. Then, in step S210, the frame memory 13
A thinning process is performed to match the number of pixels of the image signal stored in 5 with the number of display pixels of the display 241, and the processed image is displayed on the display 241.

In step S211, the photographing switch (SW)
2) The state of 152 is determined, and if the switch 152 is off, the process returns to step S202, and the operations of steps S202 to S210, that is, the shooting preparation operation, are repeatedly executed. On the other hand, if it is determined in step S211 that the photographing switch 152 is on, it is determined that a release operation has been performed, and the process proceeds to step S221.

In step S221, as in step S206, the frequency of the clock generated by the timing generator 136 for controlling the charge transfer of the image sensor 131 is set to the first frequency fL (= 12 MHz).

Next, in step S222, the state of the photographing mode (image quality mode) selection switch 153 is determined to determine whether the mode is the normal mode or the high definition mode.
If it is determined that the mode is not the high definition mode, that is, the mode is the normal mode, the process proceeds to step S223. In step S223, similarly to step S207, driving of the image sensor 131 by the low-speed clock, image signal processing, and storage in the first group of image storage areas (corresponding to the frame memory 1 in FIG. 9) of the frame memory 135 are performed. .

Then, in step S224, the compression circuit 14
3, the image signal is compressed, and in step S225, the compressed image is recorded and stored on the recording medium 144. In step S226, similar to step S210, a thinning process is performed to match the number of pixels of the captured image signal stored in the frame memory 135 with the number of display pixels of the display unit 241, and the processed image is displayed on the display unit 241. I do. Thus, the shooting in the normal mode ends, and step S20 is performed.
Return to 2.

Next, the photographing process in the high definition mode will be described.

If it is determined in step S222 that the shooting mode is the high definition mode, the process jumps to step S231. In step S231, it is determined whether or not the camera shake correction function has been selected. If the camera shake correction has been selected, the process proceeds to step S232. In step S232, the frequency of the clock generated by the timing generator 136 for controlling the charge transfer of the image sensor 131 is changed to the second frequency fH (= 24) higher than the first frequency fL.
MHz). On the other hand, when the camera shake correction is not selected, step S232 is not executed, and step S23 is performed.
The process jumps from step 1 to step S233. With this processing, the clock setting shown in FIG. 11 is performed.

In step S233, the states of the focus encoder 122 and the zoom encoder 124 are detected, and the focus and zoom states are detected. In step S234, a pixel shift waveform is set based on the optical information detected in step S233. These steps S233 and S234 are the same processing as steps S131 and S132 shown in FIG. 8 of the first embodiment.

Then, in step S235, step S235
The image sensor 131 is driven by the clock set in step 221 or S232, image signal processing is performed, and the image is stored in the first group of image storage areas (corresponding to the frame memory 1 in FIG. 9) of the frame memory 135.

In step S236, as in the first embodiment, the image shift lens 114 is driven according to the pixel shift waveforms 26 and 27 in FIG. 6 to shift the pixels.

In step S237, it is determined whether or not the pixel shift shooting has been completed. If not, the flow returns to step S235. Then, steps S235 and S236 are repeatedly executed to obtain the second to fourth sets of images while performing the pixel shift driving shown in FIG. 4, and the obtained images are stored in the frame memories 2 to 4 in the frame memory 135. Are sequentially stored. On the other hand, if it is determined in step S237 that the pixel shift shooting has been completed, the process proceeds to step S238.

In step S238, a plurality of sets of image signals obtained by shifting the pixels are synthesized using a predetermined interpolation algorithm to obtain a high-definition image signal as shown in FIG.

Subsequently, the flow jumps to step S224, where image compression, recording and storage and display are performed in steps S224 to S226 in the same manner as in the normal photographing described above.
The shooting of the high-definition image of the frame ends, and the process returns to step S202.

The processing shown in the flowchart of FIG. 12 will be outlined again below.

When the photographer turns on the main switch 150 and the photographing preparation switch (SW1) 151, the electric charges stored in the image sensor 131 are read out at the low-speed clock fL, and the image before photographing for framing confirmation is displayed on the display. 2
In addition to being displayed on 41, shooting preparation operations such as camera shake correction, photometry / aperture control, and focus adjustment are performed. Subsequently, when the shooting switch (SW2) 152 is turned on, the state of the shooting mode selection switch 153 is determined. Then, in the case of the normal shooting mode in which no pixel shift is performed,
The charges accumulated in the image sensor 131 are read out by the low-speed clock fL, subjected to image signal processing, and recorded and stored.

When the high-definition mode for performing the pixel shift is selected and the camera shake correction is not selected, there is a high possibility that the photographing is performed using a tripod. Therefore, the image is shifted while performing the pixel shift. The charges accumulated in the image sensor 131 are read out by the low-speed clock fL, subjected to image signal processing and image synthesis processing, and recorded and stored.

When the high-definition mode for performing the pixel shift is selected and the camera shake correction is also selected,
Since there is a high possibility that the image is captured by hand-held support, the image sensor 131 performs image shift for pixel shift.
Is read out by the high-speed clock fH, subjected to image signal processing and image synthesis processing, and recorded and stored.

As described above, according to the second embodiment, the imaging mode in which the imaging element is driven by a low-speed clock and the imaging mode in which the imaging element is driven by a high-speed clock can be selected even during pixel-shifted imaging. It is possible to select between shooting for obtaining a high-quality image with less image quality and shooting for reducing the effects of camera shake and subject shake, and an image suitable for the photographer's drawing intention can be obtained.

That is, since the reading speed of the photoelectric conversion signal of the image pickup device is selectively switched from at least two kinds of values at the time of the pixel shift photographing, a high-definition image with little noise can be obtained.
A desired image can be selectively photographed from high-definition images with little camera shake and subject shake.

Further, since the frequency of the charge readout clock applied to the image sensor at the time of pixel shift shooting can be switched, a high-definition image according to the photographer's intention can be obtained with a simple configuration.

Further, in the pixel shift photographing, the photographer can select between a photographing mode for obtaining a high-quality image with little noise and the like and a photographing mode for obtaining a high-definition image with little image blur. Image to be obtained.

Although the second embodiment has been described with respect to an example in which the camera switches the driving mode of the image sensor according to the result of selection of the function of camera shake correction by the photographer,
A configuration in which the photographer can directly select the driving mode of the image sensor may be used. In this case, in the camera configuration shown in FIG. 9, for example, the camera shake correction selection switch 255 is set to the imaging device drive mode changeover switch 256, and step S231 in the flowchart shown in FIG.
By performing branch control according to the state of 56, the same effect as in the second embodiment can be realized.

<Third Embodiment> Hereinafter, a third embodiment according to the present invention will be described.
An embodiment will be described.

In the above-described first and second embodiments, the configuration has been described in which the image pickup device is driven at a high speed at the time of pixel-shifted shooting to reduce the shooting time and reduce the effects of camera shake and subject shake. On the other hand, the pixel shift shooting requires a large-capacity frame memory for temporarily storing a plurality of sets of image signals. In the first and second embodiments, the entire area of the frame memory 135 is used for the pixel shift image. The signal is temporarily stored. However, in the first and second embodiments, only a part of the area of the frame memory 135 is used at the time of the normal shooting without performing the pixel shift shooting.

Therefore, in the third embodiment, the time interval for storing a plurality of sets of image signals in the frame memory is changed between the time of shooting with pixel shifting and the time of shooting with no pixel shifting, regardless of whether the pixel shifting is performed. It is characterized by utilizing the frame memory effectively.

Hereinafter, referring to FIG. 13 to FIG.
An imaging device according to the embodiment will be described.

FIG. 13 is a block diagram showing the configuration of the imaging apparatus according to the third embodiment. The imaging device according to the third embodiment includes:
In the above-described first embodiment, the function selected by the shooting mode selection switch 353 is slightly different from the imaging apparatus shown in FIG.
The only difference is that the control of the microcomputer 303 and the display mode of the display 341 change accordingly. Since other configurations are the same as those of the first embodiment, the same members are denoted by the same reference numerals as in FIG. 1 and the description is omitted.

In FIG. 13, reference numeral 303 denotes a microcomputer, which controls the operation of the camera body 301 according to a flow described later. A display 341 displays a subject image and shooting conditions. A shooting mode selection switch 353 collectively selects an image quality mode and a continuous shooting / single shooting function described later. 3
A continuous shooting function selection switch 55 is a switch for selecting a detailed function for continuous shooting when the continuous shooting mode is selected by the shooting mode selection switch 353.

FIG. 14 is a diagram showing a display form of the display 341 before photographing. The display is m as in the first embodiment.
This is a liquid crystal display panel including 2 × n2 liquid crystal display cells, and displays a subject image 371 at the time of preparation for shooting. Also,
The selected shooting mode is displayed at the lower right of the display screen.
A display 372 shows a single mode in the normal mode, that is, a mode in which normal shooting without pixel shift shooting is performed only once. A display 373 indicates a normal mode continuous shooting, that is, a mode in which normal shooting without performing pixel shift shooting is performed a predetermined number of times. A display 374 indicates a high-definition mode, that is, a high-definition shooting mode by shifting pixels. The photographing mode selection switch 35 shown in FIG.
When 3 is operated, the mode displays 372 to 374 are displayed on the display 341. The photographing mode can be switched by operating the up / down switch 154, and the result is displayed based on whether or not the triangle display portion is filled. FIG. 13 shows that the mode of continuous shooting (continuous shooting) with normal image quality without pixel shift is selected.

On the other hand, the display 373 is displayed at the lower left of the display screen.
When the normal continuous shooting mode is selected, the detailed conditions for the continuous shooting are displayed. The display 375 indicates the number of continuous shot frames,
That is, the number of consecutive photographed frames when one photographing operation is executed is displayed. The display 376 displays a continuous shooting time interval, that is, a shooting time interval of each frame of continuous shooting when one shooting operation is performed. The displays 375 and 376 can be displayed only when the normal continuous shooting mode is selected. That is, after the photographer operates the photographing mode selection switch 353 in FIG. 13 and selects the normal continuous shooting mode (display 373), the continuous shooting function selection switch 355 is selected.
Is operated, the displays 375 and 376 are displayed on the display 34.
1 is displayed. By operating the up / down switch 154, the number of continuous shot frames and the continuous shooting time interval are sequentially changed between predetermined values, and can be set to desired values. FIG. 13 shows that the number of continuous shooting frames is three and the continuous shooting time interval is set to 0.2 seconds.

FIG. 15 is a diagram showing a display form of the display 341 after photographing is performed in the continuous shooting mode set in FIG. Since images of three frames continuously shot at intervals of 0.2 seconds are displayed as 381 to 383 on the display 341,
The photographer can check whether the desired scene has been photographed by looking at the displayed image group.

FIG. 16 shows three types of shooting modes of the normal image quality single shooting, normal image quality continuous shooting, and high definition.
9 is a table comparing the number of captured images, a capturing interval, a charge transfer clock frequency of an image sensor, a time for reading (charge transfer) a set of images, and a final image size.

When the normal image quality single shooting is selected, an image of one frame is shot according to the shooting operation, the image pickup device is read out and controlled at the first low clock frequency, and the obtained image signal is stored in the frame memory. Is stored.

When the normal image quality continuous shooting is selected, an image of a predetermined frame is photographed at a predetermined time interval in accordance with the photographing operation, and the image pickup device is read out and controlled at the first low clock frequency. The image signals are sequentially stored in the frame memory.

When the high-definition mode is selected, four frames of images are photographed at the shortest time intervals that can be controlled by the camera system in accordance with the photographing operation, and the image pickup device operates at the second clock frequency higher than the first clock frequency. Reading control is performed at a clock frequency of 2, and the obtained image signals are sequentially stored in a frame memory.

FIG. 17 shows a camera body 3 according to the third embodiment.
11 is a flowchart showing control of the microcomputer 303 in the first embodiment. Hereinafter, the microcomputer 303 will be described with reference to FIGS.
Control will be described.

The main switch 15 of the camera body 301
When 0 is turned on, the microcomputer 303 exits the sleep state and proceeds from step S301 to step S302.
In step S302, the switches 151 to 152, 353, 154, and 35 in the camera body 301 are set.
5 is performed. In step S303, the state of the shooting preparation switch (SW1) 151, which is turned on by pressing the release button in the first stage, is determined. When the switch 151 is off, the process returns to step S302. When the switch 151 is turned on, the process proceeds to step S304,
The following shooting preparation operation is performed.

In step S304, the shake detection sensor 1
The camera body 301 is supplied with power, and the detection of camera shake occurring in the camera body 301 is started. Then, the microcomputer 303 calculates the driving amount of the image shift lens 114 based on the signal, drives the lens 114 to perform camera shake correction, and stabilizes the subject image. In step S305, the image sensor 131
Generator 1 to control the charge transfer
36 generates a first low frequency f
Set to L (= 12 MHz).

Step S306 collectively represents steps S106 to S108 shown in FIG. 8 of the first embodiment. The charge accumulation of the image sensor 131 and the driving of the image sensor 131 at the first frequency fL, Processing circuit 13
2 and the processed image signals are stored in a first set of image storage areas of the frame memory 135 (FIG. 13).
(Corresponding to the frame memory 1).

In the step S307, the frame memory 1
The image signal stored in 35 is read to calculate the subject luminance information. If the aperture value of the aperture 155 is inappropriate, the aperture value is re-controlled. In step S308, the frame memory 1
The image signal stored in 35 is read out, high-frequency components are extracted to detect the focus state of the subject, and the focusing lens 111 is driven to perform focusing. In step S309, a thinning process is performed to match the number of pixels of the image signal stored in the frame memory 135 with the number of display pixels of the display unit 341, and the processed image is displayed on the display unit 34.
1 is displayed.

In step S310, the photographing switch (SW)
2) The state of 152 is determined, and if the switch 152 is off, the process returns to step S302, and the operations of steps S302 to S309, that is, the shooting preparation operation, are repeatedly executed. If it is determined in step S310 that the photographing switch 152 is ON, it is determined that a release operation has been performed, and the flow advances to step S321.

In step S321, the state of the photographing mode selection switch 353 is determined to determine whether the mode is the normal mode or the high definition mode. If it is determined that the mode is not the high definition mode, that is, the mode is the normal mode, the process proceeds to step S322.

In step S322, as in step S305, the frequency of the clock generated by the timing generator 136 for controlling the charge transfer of the image sensor 131 is set to the first frequency fL (= 12 MHz).

Then, in step S323, step S3
Similarly to 06, driving of the image sensor 131 by a low-speed clock, image signal processing, and the first set of image storage areas of the frame memory 135 (corresponding to the frame memory 1 in FIG. 13)
Is stored.

In step S324, it is determined whether the shooting mode is continuous shooting or single shooting. In the case of the single shooting mode, the process jumps to step S327, and compresses the image signal of the taken one frame image in step S327.
Record and save the image compressed in step 328, step S329
To display an image on the display 341.

On the other hand, in the case of the continuous shooting mode, step S324
Then, the process proceeds to step S325. In step S325,
Timer measurement corresponding to the continuous shooting time interval selected on the display 376 in FIG. 14 is performed, and when the continuous shooting time interval has elapsed, the process proceeds to step S326.

In the step S326, the display 37 shown in FIG.
It is determined whether or not shooting for the number of continuous frames selected in step 5 has been completed. If continuous shooting for a predetermined number of frames has not been completed, the process returns to step S323 to perform shooting of the next frame. The stored image signal is stored in a predetermined image storage area (frame memory 2 to frame memory 4 in FIG. 13) of the frame memory 135.

When the continuous shooting is completed, step S326 is performed.
The process proceeds from the step S327 to a step S327, and the frame memory 135
Are respectively compressed.
In step S328, the compressed image signal is recorded and stored in the recording medium 144, and in step S329, the plurality of continuously shot images are displayed on the display 34 as shown in FIG.
1 is divided and displayed.

Thus, the photographing in the normal continuous shooting mode is completed, and the flow returns to step S302.

Next, the photographing process in the high definition mode will be described.

If it is determined in step S321 that the shooting mode is the high definition mode, the process jumps to step S331.

The processing contents of steps S331 to S337 are the same as the processing contents of steps S131 to S139 shown in FIG. 8 in the first embodiment. That is, in steps S331 and S332, a pixel shift waveform corresponding to the optical state of the imaging optical system is set, and in step S333, the frequency of the clock generated by the timing generator 136 for controlling the charge transfer of the image sensor 131 is set to Second frequency fH higher than frequency fL of 1
(= 24 MHz). Subsequently, in steps S334 to S336, 4
An image of the frame is photographed, and in step S337, a plurality of sets of image signals obtained by the pixel shift photographing are combined using a predetermined interpolation algorithm to obtain a high-definition image signal as shown in FIG.

Subsequently, the flow jumps to step S327, in which the images are compressed, stored and displayed in steps S327 to S329, and the shooting of one frame of high-definition image is completed, and the flow returns to step S302.

The processing shown in the flowchart of FIG. 17 is outlined again below.

When the photographer turns on the main switch 150 and the photographing preparation switch (SW1) 151, the electric charge stored in the image sensor 131 is read out at the low-speed clock fL, and the image before photographing for framing confirmation is displayed on the display. 3
In addition to being displayed on 41, shooting preparation operations such as camera shake correction, photometry / aperture control, and focus adjustment are performed. Subsequently, when the shooting switch (SW2) 152 is turned on, the state of the shooting mode selection switch 353 is determined. Then, in the case of the normal shooting mode in which no pixel shift is performed,
The charges stored in the image sensor 131 are read out by the low-speed clock fL, and subjected to image signal processing. In the single shooting mode, the image signal is compressed, recorded, and stored, and a shot image is displayed. On the other hand, in the continuous shooting mode, a predetermined number of frames are photographed at predetermined time intervals, and the obtained image signals are sequentially stored in the frame memory. After the photographing of a predetermined number of frames is completed, image compression and recording and saving that require a long time are executed.

When the high-definition mode in which the pixel is shifted is selected, the image is picked up while performing the image shift for the pixel shift, and the charges accumulated in the image sensor 131 are read out by the high-speed clock fH. , Are subjected to image signal processing and image synthesis processing, and are recorded and stored.

As described above, according to the third embodiment, a large-capacity frame memory for pixel-shifted photographing is provided, and when the continuous photographing mode is selected without performing pixel-shifted photographing, a predetermined time interval is set. In order to sequentially store a plurality of sets of image signals continuously shot in the pixel shifting frame memory, and to perform image recording or the like that takes a long time after that,
High-speed continuous shooting using the frame memory effectively becomes possible.

Further, since the photographer can select the number of continuous frames or the continuous photographing time interval, a continuous photograph image intended by the photographer can be obtained.

That is, in order to make the time interval of the image acquisition different between the time of acquiring a plurality of images under the pixel-shifted shooting and the time of acquiring a plurality of images under the continuous shooting without the pixel shift,
A plurality of images can be automatically taken at time intervals suitable for each shooting mode.

Also, since the acquisition interval of a plurality of images under continuous shooting without pixel shift is made longer than the acquisition interval of a plurality of images under pixel shift shooting, the influence of camera shake and subject shake during shooting with pixel shift is reduced. It is possible to perform shooting that accurately expresses the dynamic effect of the subject during continuous shooting.

Further, since the photographer can select the acquisition interval of a plurality of images under continuous shooting without performing pixel shift, the continuous shooting speed suitable for the state of the subject can be arbitrarily selected.

Further, since the photographer can select the number of photographed frames of a plurality of images under continuous photographing without pixel shift, the number of consecutive photographed frames suitable for the state of the subject can be arbitrarily selected.

Although the third embodiment has been described with respect to an example in which the single shooting mode and the continuous shooting mode are independently set, the continuous shooting mode may be unified to the single shooting mode. In this case, after shooting one frame in the single shooting mode, the shooting switch (SW
2) If 152 is operated in the off state, only one frame is photographed as a single shot, and if the photographing switch (SW2) 152 is kept in the on state after one frame is photographed, a maximum of four frames can be taken at a predetermined time interval different from the pixel shift photographing. This is continuous shooting in which continuous shooting up to the frame is performed.

In the above-described first to third embodiments, the number of exposures at the time of pixel shift and the maximum number of exposures at the time of continuous photographing have been described as four times. I just want it.

<Fourth Embodiment> Hereinafter, a fourth embodiment according to the present invention will be described.
An embodiment will be described.

In the above-described first to third embodiments, the embodiments relating to the improvement of the image pickup apparatus for obtaining a high-definition image by performing the pixel shift photographing have been described.

The fourth embodiment is characterized in that a plurality of image signals obtained by changing the exposure level of a subject image are synthesized and a set of wide dynamic range images is obtained instead of performing pixel shift.

Hereinafter, referring to FIG. 18 to FIG.
An imaging device according to the embodiment will be described.

FIG. 18 is a block diagram showing the configuration of the imaging apparatus according to the fourth embodiment. The imaging device according to the fourth embodiment includes:
In the above-described first embodiment, in the imaging apparatus shown in FIG. 1, the shooting mode selection switch 153 for selecting the pixel shift shooting is replaced with the shooting mode selection switch 453 for selecting the wide dynamic range shooting. The only difference is that the control of 403 and the display form of the display 441 change. Since other configurations are the same as those of the first embodiment, the same members are denoted by the same reference numerals as in FIG.
Description is omitted.

In FIG. 18, reference numeral 403 denotes a microcomputer, and a camera body 40 is provided in accordance with a flowchart described later.
1 is controlled. A display 441 displays a subject image and shooting conditions. A shooting mode selection switch 453 is used for setting whether or not to perform wide dynamic range shooting.

FIG. 19 is a diagram showing a display form of the display 441 before photographing. The display 441 is a liquid crystal display panel composed of m2 × n2 liquid crystal display cells as in the first embodiment, and displays a subject image 471 at the time of preparation for photographing. The selected shooting mode is displayed at the lower right of the display screen. A display 472 indicates a normal mode, that is, a normal shooting mode in which wide dynamic range shooting is not performed. On the other hand, the display 473 is a wide dynamic range mode, that is, the same subject is photographed a plurality of times with different exposure levels, and the obtained plural sets of image signals are combined to expand the dynamic range in the luminance region of the image. Indicates a shooting mode. Shooting mode selection switch 453 depending on the photographer
Is operated, the mode displays 472 and 473 are displayed on the display 441. And up-down switch 15
The photographing mode can be switched by the operation of step 4, and the result is displayed based on whether or not the triangle display portion is filled.
FIG. 19 shows that the latter wide dynamic range mode is selected.

FIG. 20 shows the state in the two types of photographing modes.
9 is a table comparing the charge transfer clock frequency of the image sensor, the read (charge transfer) time of a set of images, and the dynamic range of the final image. In the case of photographing in which the dynamic range is expanded, multiple exposures are performed by changing the exposure level. Therefore, the readout time of one image is reduced to half of that in normal imaging, and the effects of camera shake and subject shake due to the multiple exposures are reduced. Can be suppressed. On the other hand, the reading speed is not increased during normal shooting, so that unnecessary increase in power consumption can be prevented.

FIG. 21 shows a camera body 4 according to the fourth embodiment.
11 is a flowchart showing control of the microcomputer 403 in the first embodiment. Hereinafter, the microcomputer 403 will be described with reference to the flowchart of FIG.
Control will be described.

Main switch 15 of camera body 401
When 0 is turned on, the microcomputer 403 exits the sleep state and proceeds from step S401 to step S402.
In step S402, the state of each of the switches 151 to 154 and 453 in the camera body 401 is detected. In step S403, a shooting preparation switch (S
W1) The state of 151 is determined, and when the switch 151 is off, the process returns to step S402. When the switch 151 is turned on, the process proceeds to step S404,
The following shooting preparation operation is performed.

In step S404, the shake detection sensor 1
Then, the power supply to the camera body 401 is performed, and the detection of the camera shake occurring in the camera body 401 is started. Then, the microcomputer 403 calculates the driving amount of the image shift lens 114 based on the signal, drives the lens 114 to perform camera shake correction, and stabilizes the subject image. In step S405, the image sensor 131
Generator 1 to control the charge transfer
36 generates a first low frequency f
Set to L (= 12 MHz).

Step S406 is the same as that in FIG. 8 of the first embodiment.
Are collectively represented by the steps S106 to S108 shown in FIG. 5, and the charge accumulation of the image sensor 131, the driving of the image sensor 131 at the first frequency fL, and the preprocessing circuit 13
2 and the processed image signals are stored in the first set of image storage areas of the frame memory 135 (FIG. 18).
(Corresponding to the frame memory 1).

In the step S407, the frame memory 1
The image signal stored in 35 is read to calculate the subject luminance information. If the aperture value of the aperture 155 is inappropriate, the aperture value is re-controlled. In step S408, the image signal stored in the frame memory 135 is read, the high-frequency component is extracted, the focus state of the subject is detected, and the focusing lens 111 is driven to perform focusing. In step S409, a thinning process is performed to match the number of pixels of the image signal stored in the frame memory 135 with the number of display pixels of the display 441, and the processed image is displayed on the display 441.

In step S410, the state of the photographing switch (SW2) 152 is determined.
If 2 is off, the process returns to step S402, and step S40
The operations from 2 to S409, that is, the shooting preparation operation are repeatedly executed.

Next, if it is determined in step S410 that the photographing switch 152 is ON, it is determined that a release operation has been performed, and the flow advances to step S421. Step S4
At 21, the state of the photographing mode selection switch 453 is determined to determine whether the mode is the normal mode or the wide dynamic range mode. If it is determined that the mode is not the wide dynamic range mode, that is, the mode is the normal mode, the process proceeds to step S422.

In step S422, as in step S405, the frequency of the clock generated by the timing generator 136 for controlling the charge transfer of the image sensor 131 is set to the first frequency fL (= 12 MHz). In step S423, similarly to step S406, driving of the image sensor 131 by the low-speed clock, image signal processing, and storage in the first group of image storage areas (corresponding to the frame memory 1 in FIG. 18) of the frame memory 135 are performed. Do. Then, in step S424, the image signal is compressed using the compression circuit 143, and in step S425, the compressed image is recorded and stored on the recording medium 144. Next, in step S426, similar to step S409, a thinning process is performed to match the number of pixels of the captured image signal stored in the frame memory 135 with the number of display pixels of the display 441, and the processed image is displayed on the display 441. To be displayed.

With the above, shooting in the normal mode is completed.
It returns to step S402.

Next, the photographing processing in the wide dynamic range mode will be described.

If it is determined in step S421 that the shooting mode is the wide dynamic range mode, the process jumps to step S431. In step S431, the exposure conditions for the first set of photographing when photographing in the wide dynamic range mode, specifically, the aperture value of the diaphragm 113 and the charge accumulation time of the image sensor 131 are set. And step S4
In 32, the frequency of the clock generated by the timing generator 136 for controlling the charge transfer of the image sensor 131 is changed to the second frequency fH (= higher than the first frequency fL).
24 MHz), and in step S433, the image sensor 131 is driven by the clock set in step S432, image signal processing is performed, and the first of the frame memory 135 is set.
The image is stored in the image storage area of the set (corresponding to the frame memory 1 in FIG. 18).

In step S434, the exposure condition is changed for the photographing in step S433.
Specifically, the charge accumulation time of the image sensor 131 or the stop 1
By changing the aperture value of No. 13, the exposure level of the subject image is changed. When the overexposure is set with respect to the standard exposure level, the information of the high brightness area of the subject image is obtained with priority, and when the underexposure is set, the information of the low brightness area of the subject image is obtained with priority.

In the step S435, it is determined whether or not the step-exposure shooting with the exposure level shifted for expanding the dynamic range has been completed. If not completed, the process returns to the step S433. Then, steps S433 and S434 are repeatedly executed to acquire second to fourth sets of images having different exposure levels from the first set of images. Then, the obtained image is stored in the frame memory 13.
5 are sequentially stored in the areas of the frame memories 2 to 4. If it is determined in step S435 that the step exposure shooting has been completed, the process proceeds to step S436.

In step S436, a plurality of sets of image signals obtained by stepwise exposure photographing are combined using a predetermined combining algorithm to obtain a wide dynamic range image signal. Since the method disclosed in JP-A-1-319370 and JP-A-8-37628 by the present applicant is applied to the image synthesizing method in step S436, the detailed description is omitted here.

Subsequently, the flow jumps to step S424, where image compression, recording and storage are performed in steps S424 to S426 in the same manner as in the normal photographing described above, and photographing of one frame of a wide dynamic range image is completed.
Return to 402.

The processing shown in the flowchart of FIG. 21 will be outlined again below.

When the photographer turns on the main switch 150 and the photographing preparation switch (SW1) 151, the electric charge accumulated in the image pickup device 131 is read out at the low speed clock fL, and the image before photographing for framing confirmation is displayed on the display. 4
In addition to being displayed on 41, shooting preparation operations such as camera shake correction, photometry / aperture control, and focus adjustment are performed. Subsequently, when the photographing switch (SW2) 152 is turned on, the state of the photographing mode selection switch 453 is determined. Then, in the case of the normal shooting mode in which wide dynamic range shooting is not performed, the electric charges accumulated in the image sensor 131 are read out by the low-speed clock fL, subjected to image signal processing, and recorded and stored.

In the case of performing stepwise exposure for obtaining a wide dynamic range image, a plurality of photographings are performed by changing the exposure level, and the charges accumulated in each photographing are read out by the high-speed clock fH, and the image signal processing is performed. And an image synthesizing process is performed and stored.

As described above, according to the fourth embodiment, during normal photographing without stepwise exposure, the image pickup device is driven by a low-speed clock to save power and to obtain a wide dynamic range image. In such a case, the image sensor is driven by a high-speed clock to reduce the effects of camera shake and subject shake, thereby achieving both power saving and high image quality.

That is, the reading speed of the photoelectric conversion signal of the image sensor is switched between when the high-quality shooting by multiple exposures is prohibited and when the high-quality shooting is permitted, so that unnecessary power consumption is prevented, and A high-quality image according to the intention can be obtained.

Further, the frequency of the charge readout clock applied to the image pickup device is switched, and the readout speed of the photoelectric conversion signal is switched according to the photographing mode, so that a high-quality image according to the photographer's intention can be obtained with a simple configuration. be able to.

Also, during high-quality shooting by multiple exposures, a high-speed clock is applied to the charge transfer section of the image sensor, and image signals are read out at a high speed and controlled, so that the shooting time during high-quality shooting is shortened, and It is possible to obtain a high-quality image with less subject shake.

It should be noted that the same effect can be obtained by replacing the step exposure operation described in the fourth embodiment with the pixel shift photographing operation portion in the second and third embodiments.

That is, the read speed of the photoelectric conversion signal of the image sensor is selectively switched from at least two values during high-quality shooting by multiple exposures, so that a high-quality image with less noise and a high-quality image with less camera shake and subject shake are provided. A desired image can be selectively photographed from among the quality images.

<Other Embodiments> The present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a camera, a printer, etc.), and can be applied to an apparatus (for example, For example, the present invention may be applied to a digital still camera, a video camera, and the like.

An object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (or CPU) of the system or apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the function of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0192]

As described above, according to the present invention, an image pickup device capable of achieving both power saving and high image quality according to a photographing mode by making the drive clock of the image pickup device variable according to the photographing mode. And a method thereof.

[0193]

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an imaging device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of an image sensor according to the present embodiment.

FIG. 3 is a diagram showing a display mode on a display device of the embodiment.

FIG. 4 is a diagram for explaining a pixel shifting method according to the embodiment.

FIG. 5 is a diagram illustrating a high-definition image signal array after pixel-shift shooting according to the present embodiment.

FIG. 6 is a timing chart showing the drive timing of the image sensor according to the embodiment.

FIG. 7 is a table of image pickup device driving conditions according to the embodiment.

FIG. 8 is a flowchart illustrating a photographing process according to the present embodiment.

FIG. 9 is a block diagram illustrating a configuration of an imaging device according to a second embodiment of the present invention.

FIG. 10 is a diagram showing a display mode on a display device according to a second embodiment.

FIG. 11 is a table of image pickup device driving conditions according to the second embodiment.

FIG. 12 is a flowchart illustrating a photographing process according to the second embodiment.

FIG. 13 is a block diagram illustrating a configuration of an imaging device according to a third embodiment of the present invention.

FIG. 14 is a diagram showing a display mode at the time of preparation for photographing on a display device of a third embodiment.

FIG. 15 is a diagram illustrating a display mode after completion of continuous shooting on a display device according to a third embodiment.

FIG. 16 is a table of image pickup device driving conditions according to the third embodiment.

FIG. 17 is a flowchart illustrating a photographing process according to the third embodiment.

FIG. 18 is a block diagram illustrating a configuration of an imaging device according to a fourth embodiment of the present invention.

FIG. 19 is a diagram illustrating a display mode on a display device according to a fourth embodiment.

FIG. 20 is a table of image pickup device driving conditions in a fourth embodiment.

FIG. 21 is a flowchart illustrating a photographing process according to a fourth embodiment.

[Explanation of symbols]

101, 201, 301, 401 Camera body 103, 203, 303, 403 Microcomputer 104 Oscillator 111 Focusing lens 112 Zooming lens 114 Image shift lens 121 Focus actuator 123 Zoom actuator 126 Shake detection sensor 127 Image shift actuator 131 Image sensor 135 Frame memory 136 Timing generator 141, 241, 341, 441 Display 144 Recording medium 150 Main switch 151 Shooting preparation switch (SW1) 152 Shooting switch (SW2) 153, 353, 453 Shooting mode selection switch 154 Up / down switch 161 Photocell 162 Vertical transfer CCD 163 Horizontal transfer CCD 164 Timing signal input terminal 165 Image signal output terminal 17 , 271,371,471 subject image display unit 172, 173,274,275 shooting mode display section 372,273,374,472,473 photographing mode display unit 255 the camera shake correction selection switch 355 consecutive shooting function selecting switch

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 5/335 G06F 15/64 325B

Claims (22)

[Claims] An imaging unit configured to form an image of a subject; a photographing unit configured to perform a photoelectric conversion on the formed subject image to generate an image signal; Reading means for reading signals; holding means for holding the read image signals; and a plurality of image signals based on one subject image obtained by the photographing means, held by the holding means, and A synthesizing unit for synthesizing the image signal, wherein the reading unit changes a reading speed of the image signal depending on whether or not to perform the synthesizing by the synthesizing unit. 2. The image forming apparatus according to claim 1, further comprising a moving unit configured to move the image forming unit to change an image forming position of the subject image, wherein the combining unit moves the image forming position of the subject image by the moving unit. 2. The image pickup apparatus according to claim 1, wherein a plurality of image signals having different imaging positions are obtained by the photographing means, held in the holding means, and the plurality of image signals are combined. 3. An exposure adjusting unit for adjusting an exposure level of the subject image, wherein the combining unit changes an exposure level of the subject image by changing the exposure level of the subject image by the exposure adjusting unit. 2. The image pickup apparatus according to claim 1, wherein a plurality of different image signals are obtained and stored in the holding unit, and the plurality of image signals are combined. 4. An image forming means for forming a subject image, a photographing means for subjecting the formed subject image to photoelectric conversion to generate an image signal, and reading out the photoelectrically converted image signal Means, holding means for holding the read image signal, moving means for moving the image forming means to change the image forming position of the subject image, and the moving means makes the image forming position of the subject image When moving, a control means for obtaining a plurality of image signals having different imaging positions by the photographing means, holding the image signals in the holding means, and controlling to perform pixel-shift photographing for synthesizing the plurality of image signals; and Selecting means for selecting whether or not to perform the pixel shift shooting, wherein the reading means changes an image signal reading speed according to a selection result by the selecting means. Apparatus. 5. The image pickup apparatus according to claim 4, wherein said read means changes a read clock frequency in accordance with a selection result by said selection means. 6. The readout unit sets the clock frequency to a first frequency when the selection unit selects not to perform the pixel shift shooting, and sets the clock frequency to a first frequency when the pixel shift shooting is selected. The imaging apparatus according to claim 5, wherein a clock frequency is set to a second frequency higher than the first frequency. 7. An image forming means for forming a subject image, a photographing means for subjecting the formed subject image to photoelectric conversion to generate an image signal, and reading out for reading out the photoelectrically converted image signal Means, holding means for holding the read image signal, moving means for moving the image forming means to change the image forming position of the subject image, and the moving means makes the image forming position of the subject image When moving, a control means for obtaining a plurality of image signals having different imaging positions by the photographing means, holding the image signals in the holding means, and controlling to perform pixel-shift photographing for synthesizing the plurality of image signals; and A first selecting unit for selecting whether or not to perform the pixel shift photographing, and a second selecting unit for selecting a reading speed of an image signal in the reading unit. Depending on the selection result by the first and second selecting means, the image pickup apparatus characterized by changing the reading speed of the image signal. 8. The reading means according to claim 1, wherein
8. The imaging apparatus according to claim 7, wherein one of a first frequency and a second frequency higher than the first frequency is selected as a read clock frequency in accordance with a selection result by the selection unit. . 9. The imaging apparatus according to claim 7, wherein the second selection unit can select an arbitrary selection. 10. An image forming means for forming a subject image, a photographing means for subjecting the formed subject image to photoelectric conversion to generate an image signal, and reading out for reading out the photoelectrically converted image signal Means, holding means for holding the read image signal, moving means for moving the image forming means to change the image forming position of the subject image, and the moving means makes the image forming position of the subject image When moving, a plurality of image signals having different imaging positions are obtained at a first time interval by the photographing means, held in the holding means, and pixel-shifted photographing for synthesizing the plurality of image signals is performed. Pixel shift photographing control means, and a plurality of image signals having the same image forming position obtained by the image pickup means at a second time interval, and controlled to perform continuous photographing by holding the image signals in the holding means. Continuous shooting control means, first selection means for selecting whether or not to perform the pixel-shifted shooting, and when the first selection means has selected not to perform the pixel-shifted shooting, Second selecting means for selecting whether or not to perform photographing, wherein the reading means changes an image signal reading speed according to a selection result by the first and second selecting means. Characteristic imaging device. 11. The imaging device according to claim 10, wherein the second time interval is longer than the first time interval. 12. The apparatus according to claim 10, further comprising a time interval setting means for setting said second time interval.
An imaging device according to any one of the preceding claims. 13. The imaging apparatus according to claim 10, further comprising: a photographing number setting unit that sets the number of image signals held in the holding unit when performing the continuous shooting. 14. An image forming means for forming a subject image, a photographing means for subjecting the formed subject image to photoelectric conversion to generate an image signal, and reading out the photoelectrically converted image signal Means, holding means for holding the read image signal, exposure adjusting means for adjusting an exposure level of the subject image, and photographing means while changing the exposure level of the subject image by the exposure adjusting means. Control means for obtaining a plurality of image signals having different exposure levels, holding the obtained image signals in the holding means, and controlling the multi-exposure shooting to synthesize the plurality of image signals; An image pickup apparatus, comprising: a selection unit configured to select an image signal; and the reading unit changes a reading speed of the image signal according to a selection result by the selection unit. 15. An image forming step of forming an image of a subject, a photographing step of subjecting the formed subject image to photoelectric conversion to generate an image signal, and an image signal photoelectrically converted in the photographing step. And a combining step of obtaining a plurality of image signals based on one subject image in the photographing step, and combining the plurality of image signals. An image pickup method characterized in that a reading speed of an image signal is changed depending on whether or not to execute. 16. The image forming apparatus according to claim 16, further comprising a moving step of moving an image forming position of the subject image, wherein in the combining step, the image forming step differs depending on the moving of the image forming position of the subject image. 16. The imaging method according to claim 15, wherein a plurality of image signals are obtained, and the plurality of image signals are combined. 17. An exposure adjusting step for adjusting an exposure level of the subject image, wherein in the synthesizing step, a plurality of exposure levels different depending on the photographing step are changed according to a change in the exposure level of the subject image. 16. The imaging method according to claim 15, wherein a plurality of image signals are obtained and the plurality of image signals are combined. 18. An imaging method in an imaging apparatus for forming a subject image on an imaging element, performing photoelectric conversion, and reading out the image signal to obtain an image signal, wherein selection for selecting whether or not to perform imaging in a predetermined mode. And a first setting step of setting a first speed for reading out an image signal after photoelectric conversion from the image sensor when it is selected not to perform the predetermined mode shooting in the selecting step, A first photographing step of reading an image signal from the image sensor at the first speed; and, when performing the predetermined mode photographing in the selecting step, selecting the image signal after photoelectric conversion from the image sensor. A second setting step of setting a second speed for reading, a second photographing step of reading and combining a plurality of image signals from the image sensor at the second speed, Imaging method characterized in that it has. 19. The imaging method according to claim 18, wherein the second speed is higher than the first speed. 20. The method according to claim 19, wherein in the second photographing step, an image forming position of the subject image on the image sensor is moved, and a plurality of image signals having different image forming positions are obtained and synthesized. The imaging method according to claim 18. 21. The imaging method according to claim 18, wherein in the second photographing step, an exposure level of the subject image is changed, and a plurality of image signals having different exposure levels are obtained and synthesized. . 22. A computer readable memory storing a control program code in an imaging apparatus for forming an image of a subject on an imaging element, performing photoelectric conversion, and reading out the image signal to obtain an image signal. A code of a selection step of selecting whether or not to perform, and a first speed for reading out an image signal after photoelectric conversion from the imaging element when not performing the predetermined mode shooting is selected in the selection step. A code of a first setting step of setting the following; a code of a first photographing step of reading an image signal from the image sensor at the first speed; and performing the predetermined mode photographing by the selecting step. A code for a second setting step for setting a second speed for reading out the image signal after photoelectric conversion from the image sensor; A computer-readable memory characterized by having a code of a second imaging step of synthesizing reads a plurality of image signals from the imaging element by.