JP4466698B2 - Solid-state imaging device, camera using the same, and driving method of solid-state imaging device - Google Patents

Description

  The present invention relates to a solid-state imaging device and a driving method thereof, and more particularly to a solid-state imaging device suitable for use as an imaging device such as an electronic still camera and a driving method thereof. Furthermore, the present invention relates to a camera configured using a solid-state imaging device such as an electronic still camera.

In recent years, with the progress of solid-state imaging devices such as CCD (Charge Coupled Device) solid-state imaging devices, digital recording electronic still cameras using CCD solid-state imaging devices and the like as imaging devices are becoming widespread.
In an electronic still camera, in order to realize high resolution, as shown in FIG. 8, normally, a CCD solid of a so-called all-pixel readout method in which signal charges of each pixel are read independently at the same time without being mixed in a vertical CCD. An imaging device is used. According to this all-pixel readout type CCD solid-state imaging device, the vertical number is doubled when the number of pixels is the same as that of a so-called field readout type solid-state imaging device generally used in a video camera or the like. The resolution can be realized.

By the way, recently, in order to enable such an electronic still camera to be used for a long time, it is desired to reduce power consumption. As one method for realizing this, a solid-state image pickup device that is an image pickup device of an electronic still camera, in particular, consumption of a solid-state image pickup device of the solid-state image pickup device and a signal processing circuit for processing a signal obtained therefrom. It is conceivable to reduce power.
The power consumption of the body image sensor greatly depends on the drive frequency. Therefore, in order to reduce the power consumption of the solid-state image sensor, it is effective to reduce the drive frequency of the solid-state image sensor. In addition, reducing the drive frequency can be expected to reduce the power consumption because the drive frequency is directly used as the frequency of the signal processing circuit.

  However, when the drive frequency of the solid-state image sensor is lowered, the frame rate of the solid-state image sensor is also lowered accordingly. When the frame rate decreases, the amount of output signals (number of screens) output from the solid-state image sensor per unit time decreases, so a display (liquid crystal display) provided on an electronic still camera to check the composition of the subject Etc.), the motion of the image displayed is not smooth and unnatural. In addition, the solid-state image sensor is easily affected by dark current, smear, and the like, and as a result, the image quality after shooting is also affected.

Therefore, an object of the present invention is to provide a solid-state imaging device and a driving method thereof that can reduce power consumption without affecting the number of screens output from the solid-state imaging device.
Furthermore, the present invention provides a camera that can reduce the power consumption of the solid-state imaging device without affecting the movement of the image displayed on the display and the image quality after shooting. The purpose is to provide.

  The solid-state imaging device according to the present invention is capable of selectively taking the all-pixel readout mode in which the signal charges of all the pixels are independently read at the same time and the thinning-out readout mode in which the signal charges are read out from only a part of the pixel columns in the vertical direction. An imaging element; and a frequency variable unit that varies a driving frequency of the solid-state imaging element according to an operation mode, and the solid-state imaging unit is configured to reduce the driving frequency to 1 / m (m is a natural number). The image sensor is configured to perform 1 / n decimation readout that reads out only one of n (n is a natural number) pixels, so that the frame rate is set to n / m, and n = m is set. It is characterized by being.

  The driving method according to the present invention is a solid-state imaging that can selectively take all-pixel readout mode in which signal charges of all pixels are independently read out at the same time and thinning-out readout mode in which signal charges are read out only from some pixel columns in the vertical direction. In a driving method of a solid-state imaging device provided with an element, the solid-state imaging element can be obtained even if the driving frequency of the solid-state imaging element is varied according to an operation mode and the driving frequency is reduced to 1 / m (m is a natural number). 1 / n thin-out readout that reads out only one of n (n is a natural number) pixels, so that the frame rate is set to n / m and n = m is set. It is characterized by.

  According to the solid-state imaging device having the above configuration and the driving method thereof, the driving frequency of the solid-state imaging device is varied according to the operation mode. As a result, for example, the driving frequency of the solid-state imaging device in the thinning readout mode can be made 1 / m lower than the driving frequency in the all-pixel readout mode. In this case, 1 / n thinning readout is performed in which signal charges are read out from only a part of the pixel columns in the vertical direction, so the number of screens output from the solid-state imaging device per unit time even if the drive frequency is lowered. Will not decrease. That is, by setting n = m, there is no change in the frame rate between the thinning readout mode and the all-pixel readout mode. In addition, in the thinning readout mode, the power consumption of the solid-state imaging device is reduced by lowering the drive frequency.

  In addition, the camera according to the present invention is capable of selectively taking the all-pixel readout mode in which the signal charges of all the pixels are independently read at the same time and the thinning-out readout mode in which the signal charges are read out from only a part of the pixel columns in the vertical direction. An imaging element; and a frequency variable unit that varies a driving frequency of the solid-state imaging element according to an operation mode, and the solid-state imaging unit is configured to reduce the driving frequency to 1 / m (m is a natural number). The image sensor is configured to perform 1 / n decimation readout that reads out only one of n (n is a natural number) pixels, so that the frame rate is set to n / m, and n = m is set. It is characterized by being.

According to the camera having the above configuration, the driving frequency of the solid-state imaging device is varied according to the operation mode. Accordingly, in this camera, for example, the driving frequency of the solid-state imaging device in the thinning readout mode can be made 1 / m lower than the driving frequency in the all-pixel readout mode. In this case, 1 / n thinning readout is performed in which signal charges are read out from only a part of the pixel columns in the vertical direction, so the number of screens output from the solid-state imaging device per unit time even if the drive frequency is lowered. Will not decrease. That is, by setting n = m, there is no change in the frame rate between the thinning readout mode and the all-pixel readout mode. Therefore, the movement of the displayed image does not become smooth and unnatural when displayed by the display means. In addition, the power consumption of the solid-state imaging device is reduced by lowering the drive frequency.
Further, if the driving frequency of the solid-state imaging device is not lowered in the all-pixel reading mode, it is possible to prevent the image quality of the shooting data from being lowered when the shooting data is stored in the storage unit.

  As described above, according to the solid-state imaging device and the driving method thereof according to the present invention, since the driving frequency of the solid-state imaging device is varied according to the operation mode, the driving frequency in the thinning-out readout mode is the same as that in the all-pixel readout mode. It is possible to reduce the power consumption of the solid-state imaging device while preventing the frame rate from decreasing. That is, the power consumption of the solid-state imaging device can be reduced without affecting the number of screens output from the solid-state imaging device.

  Further, according to the camera of the present invention, since the driving frequency of the solid-state imaging device is varied according to the operation mode, the operation mode and the driving frequency can be switched between the confirmation of the composition of the subject and the storage of the shooting data. . Thereby, in this camera, the power consumption of the solid-state imaging device, that is, the camera can be reduced without affecting the movement of the display image at the time of composition confirmation and the image quality after shooting.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of an example of a CCD solid-state imaging device according to the present invention.
As shown in FIG. 1, the CCD solid-state imaging device according to the present embodiment includes a CCD solid-state imaging device 10 and a timing generation circuit 20.

The CCD solid-state imaging device 10 is provided with an imaging area 11.
The imaging area 11 is arranged in a matrix in a row (vertical) direction and a column (horizontal) direction, a plurality of sensor units 12 that convert incident light into signal charges having a charge amount corresponding to the amount of light, and these sensors A plurality of vertical CCDs 14 are provided for each vertical row of the sensor units 12 and vertically transfer signal charges read from the sensor units 12 by the read gate unit 13.

  In the imaging area 11, the sensor unit 12 is made of, for example, a PN junction photodiode. The signal charge accumulated in the sensor unit 12 is read out to the vertical CCD 14 by applying a read pulse XSG described later to the read gate unit 13. The vertical CCD 14 is configured to drive, for example, three-layer electrodes and three phases (φV1 to φV3), and the signal charge read from each sensor unit 12 is scanned by one scanning line (one line) in a part of the horizontal blanking period. ) Are sequentially transferred in the vertical direction.

  Here, in the vertical CCD 14, the transfer electrode of the second layer (φV 2) also serves as the gate electrode of the read gate unit 13. Therefore, among the three-phase vertical transfer clocks φV1 to φV3, the second-phase vertical transfer clock φV2 is at a low level (hereinafter referred to as “L” level) and an intermediate level (hereinafter referred to as “M” level). Further, the three values of the high level (hereinafter referred to as “H” level) are set, and the third “H” level pulse becomes the read pulse XSG applied to the read gate unit 13. .

  A horizontal CCD 15 is disposed below the imaging area 11 in the drawing. Signal charges corresponding to one line are sequentially transferred from the plurality of vertical CCDs 14 to the horizontal CCD 15. The horizontal CCD 15 is configured to drive, for example, two-layer electrodes and two phases (φH1, φH2), and the signal charges for one line transferred from the plurality of vertical CCDs 14 are sequentially transferred in the horizontal scanning period after the horizontal blanking period. Transfer horizontally.

At the end of the transfer destination of the horizontal CCD 15, for example, a charge / voltage converter 16 having a floating diffusion amplifier configuration is provided. The charge-voltage converter 16 sequentially converts the signal charges transferred horizontally by the horizontal CCD 15 into voltage signals and outputs the voltage signals. This voltage signal is derived as a CCD output OUT corresponding to the amount of incident light from the subject.
The CCD solid-state imaging device 10 is configured as described above.

Various timing signals including vertical transfer clocks φV1 to φV3 and horizontal transfer clocks φH1 and φH2 for driving the CCD solid-state imaging device 10 thus configured are generated by the timing generation circuit 20.
The timing generation circuit 20 includes an original oscillator 22, a frequency divider 23, and a selector 24 in addition to a TG (Timing Generator) unit 21 that generates various timing signals.

  The TG unit 21 is an all-pixel reading mode in which signal charges of all pixels are independently read at the same time in accordance with a mode signal given from the outside, and a thinning-out reading mode in which signal charges are read from only a part of pixel columns in the vertical direction. It is the structure which can take. For the second phase vertical transfer clock φV2, two clocks (φV2 and φV2 ′) are generated in order to correspond to these two modes.

  The original oscillator 22 oscillates a reference pulse having a predetermined frequency. The frequency divider 23 divides the reference pulse oscillated by the original oscillator 22 into 1 / m (where m is a natural number). The selector 24 performs switching for supplying either the reference pulse from the original oscillator 22 or the pulse signal after frequency division by the frequency divider 23 to the TG unit 21. This switching is performed according to two operation modes, that is, an all-pixel readout mode and a thinning readout mode.

  FIG. 2 is a plan pattern diagram showing an example of a specific configuration of the unit pixel, and FIG. 3 shows a cross section taken along the line XX ′. First, the vertical CCD 14 includes a transfer channel 33 made of an N-type impurity formed on an N-type substrate 31 via a P-type well 32, and a three-phase array arranged repeatedly in the transfer direction above the transfer channel 33. Transfer electrodes 34-1 to 34-3. Of these transfer electrodes 34-1 to 34-3, the first-phase transfer electrode 34-1 is formed of the first-layer polysilicon (indicated by a one-dot chain line in the figure), and the second-phase transfer electrode 34-2. Is formed by the second layer polysilicon (indicated by a two-dot chain line in the figure), and the third-phase transfer electrode 34-3 is formed by the third layer polysilicon (indicated by a broken line in the figure). .

  FIG. 4 is a wiring pattern diagram of the transfer electrodes 34-1 to 34-3 in the vertical CCD 14. In the present wiring system, in order to enable thinning-out reading driving, the device of the second-phase vertical transfer clock φV2 is devised. Specifically, as described above, two vertical transfer clocks φV2 and φV2 ′ are prepared as the vertical transfer clocks for the second phase, and further, in order to transmit the vertical transfer clocks φV1, φV2, φV2 ′, and φV3. Four bus lines 41 to 44 are wired. FIG. 5 shows the phase relationship between the vertical transfer clocks φV1, φV2, φV2 ′, φV3 during the line shift period.

  The first-phase transfer electrodes 34-1 and 34-3 of all the pixels are connected to the bus lines 41 and 44 that transmit the vertical transfer clocks φV1 and φV3. Further, the bus line 42 for transmitting the vertical transfer clock φV2 is connected to the transfer electrodes 34-2 for the second phase of these pixels every four pixels in units of three pixels before and after, and transmits the vertical transfer clock φV2 ′. To the bus line 43, the transfer electrodes 34-3 of the second phase of these pixels are connected every third pixel, with the four pixels other than the pixels connected to the bus line 42 as a unit B.

  As described above, the vertical transfer clocks φV 2 and φV 2 ′ are read pulses XSG applied to the gate electrode of the read gate unit 13 when the third “H” level pulse reads signal charges from the sensor unit 12. It becomes. In the all-pixel read mode, the read pulse XSG is set on both the vertical transfer clocks φV2 and φV2 ′, whereas in the thinning-out read mode, the read pulse XSG is set only on the vertical transfer clock φV2.

  That is, in the all-pixel readout mode, the signal charge is read from all the pixels by setting the readout pulse XSG on both the vertical transfer clocks φV2 and φV2 ′. On the other hand, in the thinning-out reading mode, the signal charge is read every four lines in units of three lines by setting the reading pulse XSG only at the vertical transfer clock φV2. In other words, the readout of the signal charge is thinned out every 3 lines with 4 lines as a unit.

  In this example, as an example, in the color CCD solid-state image pickup device, the case where thinning readout is performed every 4 lines in units of 3 lines corresponding to the color coding of the color filter is shown as an example. The present invention is not limited, and arbitrary thinning-out reading can be performed only by changing the wiring pattern of the vertical transfer clocks φV2 and φV2 ′ in FIG. 4 such as every two lines in units of four lines or every other line in units of two lines. Can be set.

  Incidentally, the timing generation circuit 20 includes an original oscillator 22, a frequency divider 23, and a selector 24 in addition to a TG unit 21 configured to be able to take an all-pixel reading mode and a thinning-out reading mode in accordance with a mode signal given from the outside. is doing. Thereby, in this timing generation circuit 20, the selector 24 can switch whether the reference pulse from the original oscillator 22 is supplied to the TG unit 21 as it is or the reference pulse is divided by 1 / m. It has become. This switching is performed in accordance with a mode signal given from the outside as in the TG unit 21.

Specifically, the selector 24 performs switching so that the reference pulse is directly applied to the TG unit 21 in the all-pixel readout mode, and the 1 / m-division pulse signal is applied to the TG unit 21 in the thinning readout mode.
At this time, the TG unit 21 uses the vertical transfer clocks φV1 to φV3 and the horizontal transfer clocks φH1 and φH2 for driving the CCD solid-state imaging device 10 based on the given reference pulse or the pulse signal after 1 / m frequency division. Various timing signals including are generated. For this reason, the frequency of the timing signal generated in the thinning readout mode is 1 / m of the timing signal generated in the all-pixel readout mode. That is, in the thinning readout mode, the driving frequency supplied to the CCD solid-state imaging device 10 is 1 / m in the all pixel readout mode.

When the drive frequency becomes 1 / m, the frame rate is reduced to 1 / m in the CCD solid-state imaging device 10 to which the drive frequency is supplied.
However, at this time, the CCD solid-state imaging device 10 operates in the thinning readout mode. That is, by performing 1 / n decimation readout that reads out only one of n (where n is a natural number) pixels, the frame rate can be increased by a factor of n compared to the all-pixel readout mode. .

Therefore, even if the driving frequency becomes 1 / m, the frame rate becomes n / m by performing 1 / n thinning readout. Here, if n = m, there is no change in the frame rate from that in the all-pixel readout mode.
In addition, when the driving frequency is 1 / m, the CCD solid-state imaging device 10 to which the driving frequency is supplied can reduce power consumption.

  As described above, in the CCD solid-state imaging device and the driving method thereof according to the present embodiment, the driving frequency supplied to the CCD solid-state imaging device 10 is varied according to the operation mode. As a result, the driving frequency in the thinning-out readout mode can be reduced to 1 / m in the all-pixel readout mode, and the power consumption of the CCD solid-state imaging device 10 can be reduced while preventing the frame rate from being lowered. Become. That is, power consumption can be reduced without affecting the number of screens output from the CCD solid-state imaging device 10.

  In the CCD solid-state imaging device of this embodiment, the driving frequency is varied by the original oscillator 22, the frequency divider 23 and the selector 24 provided in the timing generation circuit 20. Therefore, the drive frequency can be varied simply by adding the original oscillator 22, the frequency divider 23, and the selector 24 to the TG unit 21, and the above-described reduction in power consumption can be easily realized. Further, the TG unit 21 can be used as it is as long as it has a configuration capable of taking the all-pixel readout mode and the thinning readout mode in accordance with a mode signal given from the outside. It becomes easy.

  Next, a digital recording electronic still camera using the above CCD solid-state imaging device as an imaging device will be described. FIG. 6 is a schematic configuration diagram of an example of an electronic still camera according to the present invention.

  As shown in FIG. 6, the electronic still camera includes an optical lens 101, a sample hold (S / H) circuit 102, an A / D converter 103, a camera signal, in addition to the CCD solid-state imaging device 10 and the timing generation circuit 20. A processing circuit 104, a data switcher 105, a conversion circuit 106, a liquid crystal display (hereinafter abbreviated as LCD) 107, an encoder / decoder 108, a DRAM (Dynamic Random Access Memory) 109, a memory control 110, and a flash memory 111 are provided. Yes.

  When the optical lens 101 forms an optical image of the subject on the CCD solid-state imaging device 10 as a two-dimensional image, the S / H circuit 102, the A / D converter 103, and the camera signal processing circuit 104 are sequentially arranged in the CCD solid state. Each voltage signal obtained from the image sensor 10 is processed as necessary. The data switcher 105 multiplexes signals processed by the camera signal processing circuit 104, such as luminance data and color difference data, in accordance with mode switching signals (CAM, Rec, Play) generated based on user key operations or the like. The transmission destination of the component signal (Y, Cr, Y, Y, Cb, Y)) is switched.

When a component signal is sent to the conversion circuit 106 by switching at the data switcher 105, the conversion circuit 106 converts the component signal into three primary color signals (R, G, B) and sends it to the LCD 107. To display as a visible image.
Further, when a component signal is sent to the encoder / decoder 108 via the recording / reproducing data bus 112 by switching at the data switcher 105, the encoder / decoder 108 performs JPEG (Joint Photographic Experts Group), that is, adaptation. Data compression of the component signal is performed by encoding DCT (Discrete Cosine Transform). However, high efficiency encoding other than JPEG may be used.

A DRAM 109 is provided for the blocking processing in JPEG. The operation of the DRAM 109 is controlled by an address signal and a control signal supplied from the memory controller 110.
When the encoder / decoder 108 performs JPEG data compression, the compressed data is stored in the flash memory 111 as photographed data. The flash memory 111 is a semiconductor memory that retains stored contents even when the power is turned off, and can be erased and rewritten electrically collectively for the entire memory or for each divided area. However, a non-volatile memory other than the flash memory 111 may be used.

  That is, the electronic still camera in the present embodiment is obtained by the optical lens 101 that forms an optical image of a subject as a two-dimensional image, the solid-state imaging device that performs photoelectric conversion on the formed image, and the photoelectric conversion. The flash memory 111 that stores the electrical signal as photographic data, and when the photographic data is stored in the flash memory 111, the electrical signal obtained by photoelectric conversion is displayed as a visible image in order to confirm the composition of the subject. LCD 107 is provided.

Here, in the electronic still camera configured as described above, a sequence operation when photographing a subject will be described with reference to FIG.
When photographing a subject, the electronic still camera first allows the user to confirm (monitor) the composition of the subject based on the display screen of the LCD 107.

At this time, since the display screen on the LCD 107 is used for monitoring, that is, for checking the angle of view, no problem occurs even if the image quality is somewhat deteriorated. However, the movement is required to be smooth and natural.
In addition, normally, the time spent for this monitoring is the longest in the sequence operation for photographing the subject.

Therefore, in this electronic still camera, as shown in FIG. 7A, the driving mode at the time of monitoring is set to the a mode. In the a mode, as shown in FIG. 7B, the drive frequency supplied to the CCD solid-state imaging device 10 is the one after 1 / m division, and the signal charge is read in the 1 / n thinning readout mode. This is a mode in which the frame rate does not decrease (becomes n / m) as a result.
Thereby, at the time of monitoring, the movement of the display screen on the LCD 107 does not become smooth or unnatural, and the power consumption of the CCD solid-state imaging device 10 can be reduced.

  When the confirmation of the composition of the subject is completed as a result of the monitoring, the electronic still camera subsequently performs optical detection by causing the user to half-press the shutter, as shown in FIG. The optical detection is performed in order to realize functions such as auto focus (AF), auto exposure (AE), auto white balance (AWB), and camera shake detection. In this case, it is necessary to obtain signals for several frames from the CCD solid-state imaging device 10 in an instant.

Therefore, in this electronic still camera, the driving mode at the time of optical detection is set to b mode. As shown in FIG. 7B, the b mode is a result obtained by reading the signal charge in the 1 / n decimation readout mode without dividing the drive frequency supplied to the CCD solid-state imaging device 10. In this mode, the frame rate is increased (n times).
Thereby, at the time of optical detection, signals necessary for AF, AE, AWB, camera shake detection, etc. can be obtained reliably and quickly. Note that the signal obtained at this time is used for AF, AE, AWB, camera shake detection, and the like, so the image quality is not limited.

When the optical detection is completed, the electronic still camera then causes the user to fully press the shutter as shown in FIG. However, the best image quality is required at this time. Therefore, here, the drive mode is the c mode. In the c mode, as shown in FIG. 7B, signal charges are read in the all-pixel reading mode (normal mode). Further, in order to prevent the influence of dark current, smear, etc., the drive frequency is not divided.
When the storage of the shooting data is completed, the electronic still camera enters the monitoring state again.

  However, the electronic still camera is preset to operate in the a mode during monitoring, the b mode during optical detection, and the c mode during data storage. Based on the setting and the shutter state, a CPU (not shown) Central Processing Unit) gives an operation instruction to each part including the timing generation circuit 20.

  As described above, the electronic still camera according to the present embodiment operates in the 1 / n decimation readout mode at the time of monitoring for confirming the composition of the subject, and the driving frequency supplied to the CCD solid-state imaging device 10 is 1 / m. It is supposed to be the one after frequency division. As a result, the power consumption of the CCD solid-state imaging device 10 can be reduced while preventing the frame rate from decreasing. That is, it is possible to realize both conflicting matters such as the degree of recognition as a moving image on the display screen during monitoring and the reduction of power consumption. In particular, since the time spent for the monitoring is the longest in the sequence operation for photographing the subject, it is very effective to reduce the power consumption during the monitoring.

  Further, in this case, if n = m, there is no change in the frame rate, so that signal processing in the S / H circuit 102, A / D converter 103, or camera signal processing circuit 104 becomes easy.

Further, the electronic still camera of the present embodiment is configured to operate in the all-pixel reading mode and not to divide the driving frequency when shooting data is stored. As a result, the image quality of the stored shooting data does not deteriorate.
That is, in this electronic still camera, by switching the operation mode and the driving frequency between monitoring and saving of shooting data, the CCD does not affect the movement of the image displayed on the LCD 107 and the image quality after shooting. The power consumption of the solid-state imaging device 10, that is, the electronic still camera can be reduced.

  In the present embodiment, the case where the present invention is applied to an electronic still camera that captures still images has been described. However, the present invention is not limited to this. For example, the present invention can be applied even to a video camera that shoots a moving image. If the driving frequency of a solid-state imaging device mounted on the video camera is varied according to the operation mode, the above-described case is possible. The same effect as the case can be obtained.

It is a schematic block diagram of an example of embodiment of the solid-state imaging device concerning this invention. It is a plane pattern figure which shows an example of a structure of a unit pixel. FIG. 3 is a sectional structural view taken along the line XX ′ in FIG. 2. It is a wiring pattern diagram of a vertical CCD. It is a timing chart which shows the phase relationship of a three-phase vertical transfer clock. It is a schematic block diagram of an example of embodiment of the camera concerning this invention. FIG. 7 is an explanatory diagram illustrating an example of a sequence operation when shooting a subject in the camera of FIG. 6, (A) shows a timing chart of the sequence operation, and (B) shows a relationship between the operation mode and the drive frequency. ing. It is explanatory drawing of an all-pixel reading system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... CCD solid-state image sensor, 11 ... Imaging area, 12 ... Sensor part, 14 ... Vertical CCD, 15 ... Horizontal CCD, 16 ... Charge voltage conversion part, 20 ... Timing generation circuit, 22 ... Original oscillator, 23 ... Frequency divider , 24 ... selector, 101 ... optical lens, 107 ... LCD, 111 ... flash memory

Claims (8)

A solid-state imaging device capable of selectively taking an all-pixel readout mode of independently reading out signal charges of all pixels at the same time and a thinning-out readout mode of reading out signal charges from only a part of the pixel columns in the vertical direction;
Frequency varying means for varying the drive frequency of the solid-state imaging device according to the operation mode,
Even if the frequency variable means lowers the drive frequency to 1 / m (m is a natural number), the solid-state imaging device performs 1 / n decimation readout that reads out only one of n (n is a natural number) pixels. Accordingly, the solid-state imaging device is configured such that the frame rate is set to n / m and n = m is set. The solid-state imaging device according to claim 1, wherein the frequency varying unit makes a driving frequency in the thinning readout mode lower than a driving frequency in the all-pixel readout mode. The frequency variable means includes
An oscillator that oscillates a reference pulse of a predetermined frequency;
A frequency divider for dividing a reference pulse generated by the oscillator;
A selector that supplies either a reference pulse oscillated by the oscillator or a pulse signal after frequency division by the frequency divider to the solid-state imaging device according to an operation mode. 2. The solid-state imaging device according to 2. A solid-state imaging device capable of selectively taking an all-pixel readout mode of independently reading out signal charges of all pixels at the same time and a thinning-out readout mode of reading out signal charges from only a part of the pixel columns in the vertical direction;
Frequency varying means for varying the drive frequency of the solid-state imaging device according to the operation mode,
Even if the frequency variable means lowers the drive frequency to 1 / m (m is a natural number), the solid-state imaging device performs 1 / n decimation readout that reads out only one of n (n is a natural number) pixels. Accordingly, the frame rate is configured to be n / m, and n = m is set. An optical lens that forms an optical image of a subject as a two-dimensional image;
A solid-state imaging device that performs photoelectric conversion on an image formed by the optical lens;
Storage means for storing electrical signals obtained by photoelectric conversion in the solid-state imaging device as photographing data;
A display unit that displays the electrical signal obtained by photoelectric conversion in the solid-state imaging device in the form of a visible image when storing the photographing data in the storage unit;
The camera according to claim 4, wherein the solid-state imaging device includes the solid-state imaging device and the frequency variable unit. In the solid-state imaging device, the thinning readout mode is set at the time of display by the display means, and the all-pixel readout mode is set at the time of taking an electric signal into the storage means,
The camera according to claim 5, wherein the frequency varying unit makes the drive frequency in the thinning readout mode lower than the drive frequency in the all-pixel readout mode. Solid-state imaging device having a solid-state imaging device capable of selectively taking all-pixel readout mode in which signal charges of all pixels are independently read out at the same time and thinning-out readout mode in which signal charges are read out only from a partial pixel column in the vertical direction In the driving method of
The drive frequency of the solid-state image sensor is varied according to the operation mode,
Even if the driving frequency is reduced to 1 / m (m is a natural number), the solid-state imaging device performs 1 / n thinning readout for reading out only one of n (n is a natural number) pixels, thereby A method for driving a solid-state imaging device, wherein the rate is set to n / m and n = m is set. 8. The solid state according to claim 7, wherein when reading signal charges from the solid-state image sensor in the thinning readout mode, a drive frequency of the solid-state image sensor is made lower than a drive frequency in the all-pixel readout mode. Driving method of imaging apparatus.

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