JPH10200811A - Photoelectric converting device and automatic focus adjustment camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a control method for the amplification factors of respective amplifiers. SOLUTION: The amplification factors of a 1st amplifier AMP1 and a 2nd amplifier AMP2 are set according to amplification factor control signals Gx at the time of reception of a charge storage start command Tm and a charge storage end command Tm. For example, the amplification factor of the 1st amplifier AMP1 is set according to the level of the amplification factor control signal Gx at the time of the charge storage start command Tm reception and the amplification factor of the 2nd amplifier AMP2 is set according to the level of the amplification factor control signal Gx at the time of the charge storage end command Tm reception.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a photoelectric conversion device and an automatic focusing camera incorporating the photoelectric conversion device.

[0002]

2. Description of the Related Art A subject image formed by a focus detection optical system is received by a charge storage type image sensor, the output of the image sensor is processed, and the defocus amount of the subject image plane with respect to a predetermined focal plane of a photographing optical system. There is known an automatic focusing camera that detects an image and drives a focusing lens according to the defocus amount to focus an imaging optical system. In the automatic focus adjustment of this type of camera, whether or not the defocus amount can be detected and the reliability of the obtained defocus amount largely depend on the level of contrast, which is the light luminance distribution of the subject. Therefore, it is necessary to optimally reflect the contrast of the subject on the output of the image sensor.

For example, in the case of a subject as shown in FIG. 11A, it is desirable that the output be as shown in FIG. 11C. In the figure, Vsat indicates the saturation level of the photoelectric conversion element. By the way, if the accumulation time is short, the contrast becomes low as shown in FIG. Conversely, if the accumulation time is long, the contrast that should be originally present disappears as shown in FIG. Therefore, it is necessary to obtain an image output of an appropriate size, and for that purpose, it is necessary to accumulate charges in an appropriate accumulation time.

In order to determine the appropriate accumulation time, the accumulation time is determined such that the output peak value in the next accumulation operation becomes an appropriate value based on the accumulation time in the previous accumulation operation and the image output of the image sensor. Is calculated. For example, it is assumed that an output as shown in FIG. 11B is obtained, the accumulation time at that time is Tb, and the peak output is Vb. In this case, in order to obtain an appropriate output shown in FIG.

## EQU1 ## Tc = (Vc / Vb) .Tb Where Vc is the target value,

## EQU2 ## Vc = A.Vsat A is a positive real number less than 1, and the size of A determines the "appropriate size" of the image output. If A is small, the contrast of the image output will always be low. Conversely, if A is large, the brightness of the subject will be slightly increased and the image output will be saturated immediately. However, it is assumed that the above image output magnitude does not include noise components such as dark current. This method will be referred to as AGC (Auto Gain Control)
Call.

[0005] Here, when the subject is dark, the accumulation time becomes long if an attempt is made to obtain an image output of an appropriate size. However, if the obtained image output is amplified by an amplifier, the shortest accumulation time is inevitably determined by the operation clock of the microcomputer that controls the image sensor, so the image output immediately saturates when the subject is bright. Would. Therefore, set the amplifier gain to Low.
And Hi can be switched to two amplification factors,
It can handle both dark and bright subjects. In the following, in order to cope with the luminance of a subject that changes over a wide range from low luminance to high luminance, an amplifier is connected in series with 2 luminance.
A method of AGC in the case where one is provided will be described.

FIG. 4 shows a configuration of a conventional automatic focusing camera incorporating a charge storage type photoelectric conversion device. The light beam from the subject passes through the objective lens 1 and the focus detection optical system 2 to form an image on the image sensor 3. The output of the image sensor 3 is amplified through the first amplifier 4 and the second amplifier 5,
After being A / D converted by the A / D converter 6, it is input to the arithmetic unit 7. The calculation unit 7 performs a focus detection calculation based on the data of the A / D conversion unit 6, and calculates the defocus amount of the objective lens 1. The drive control unit 10 drives the motor 11 based on the defocus amount, and drives the objective lens 1 to focus. The calculation unit 7 performs an AGC operation based on the data used for the focus detection calculation. In other words, data on the next accumulation time of the image sensor and the amplification factors of the first amplifier 4 and the second amplifier 5 are calculated, and the sensor control unit 8
Output to Then, the sensor control unit 8 drives and controls the image sensor 3 based on the data,
The amplification factors of the first amplifier 4 and the second amplifier 5 are switched. Here, the image sensor 3, the first amplifier 4, the second amplifier 5, and the sensor control unit 8 are one sensor chip 9.
It is assumed that it is formed above.

FIG. 5 shows the structure of the sensor chip 9. P
.., PEn are charge storage type photoelectric conversion elements, and constitute a charge storage type photoelectric conversion element array as a whole. OVD is an overflow drain provided along the charge storage photoelectric conversion element array, and OVG is an overflow gate provided between the overflow drain OVD and the charge storage photoelectric conversion element array. During non-charge storage, the overflow gate OVG is opened, and charges generated in the charge storage type photoelectric conversion element array are transferred to the overflow drain OVD.

[0008] SR is a CCD analog transfer register, SG
Is a transfer gate provided between the charge storage type photoelectric conversion element array and the transfer register SR. When the charge accumulation of the charge storage type photoelectric conversion element array is completed, the transfer gate SG is once opened to transfer the charge accumulated in the charge storage type photoelectric conversion element array to the transfer register SR. Thereafter, the charges are serially transferred leftward by the transfer register SR, converted into a voltage corresponding to the charges, and then output as image signals from the transfer register SR. AMP1 is the first amplifier, AM
P2 is a second amplifier, which amplifies the image signal from the transfer register SR and outputs it as a signal Vout. The output Vout is supplied to an A / D converter (not shown).

Reference numeral DRV denotes a sensor control circuit which stores two-phase operation clocks CLK1 and CLK2 in a transfer register SR.
Supply. In addition, a control signal OGP for controlling the overflow gate OVG is supplied along with the control of the start and end of the charge accumulation. Also, a control signal SGP for controlling the transfer gate SG in accordance with the control of the end of the charge accumulation.
Supply. The sensor control circuit DRV is supplied with an accumulation time control signal Tm for instructing start and end of charge accumulation from an external arithmetic circuit (not shown). Further, a first amplifier gain control signal G1 for switching the gain of the first amplifier is supplied from an external arithmetic circuit (not shown). Further, a second amplifier gain control signal G2 for switching the gain of the second amplifier is supplied from an external arithmetic circuit (not shown).

The operation of the photoelectric conversion device having the above configuration will be described with reference to the time chart of FIG. The operation clocks CLK1 and CLK2 are supplied to the transfer register SR, and the transfer register SR constantly performs a transfer operation. The period from time t1 to t2 when the accumulation time control signal Tm is Hi is the charge accumulation time of the charge accumulation type photoelectric conversion element array. Until time t1, the control signal OGP is Hi and the overflow gate OVG is open, so that the charges generated in the charge storage type photoelectric conversion element array are not stored in the charge storage type photoelectric conversion element array but are sent to the overflow drain OVD. I have. The accumulation time control signal Tm that has become Hi at time t1.
Is supplied to the sensor control circuit DRV, the sensor control circuit DRV changes the control signal OGP to Low, closes the overflow gate OVG, and starts the charge accumulation in the charge accumulation type photoelectric conversion element array. When the calculation unit (not shown) sets the accumulation time control signal Tm to Low at time t2, the sensor control circuit DRV sets the control signal SGP to Hi to open the transfer gate SG, and stores the charge accumulated in the charge accumulation type photoelectric conversion element array. The data is transferred to the transfer register SR.

The sensor control circuit DRV operates at time t2.
Based on the first amplifier gain control signal G1 and the Hi / Low state of the second amplifier gain control signal G2.
The amplification factors of the amplifier and the second amplifier are switched. Time t
At a time t3 when a predetermined time has elapsed since the second time, the sensor control circuit D
The RV sets SGP to Low, closes the transfer gate SG, and sets the control signal OGP to Hi to set the overflow gate OVG.
Is opened, and the charges generated in the charge storage type photoelectric conversion element array are transferred to the overflow drain OVD again. On the other hand, the charge transferred by the transfer register SR is converted into a voltage, amplified by the first amplifier AMP1 and the second amplifier AMP2, and generated as a signal Vout from time t4. After time t4, PE1, P
E2... A signal corresponding to the amount of charge accumulated in PEn appears as a time-series signal.

Here, the first and second amplifiers each have L
There are two amplification factors of ow and Hi, and the amplification factor of Hi to Low is β times in the first amplifier 4 and α in the second amplifier 5.
Double it. The total gain based on the combination of the gains of the first and second amplifiers is such that the gain of the first amplifier 4 is Low.
If the amplification factor of the second amplifier 5 is Low (called “LL”), it is set to 1, β is “HL”, and “L” is “L”.
In the case of “H”, it becomes α times, and in the case of “HH”, it becomes α · β times.
Here, it is assumed that α is larger than β.

At time t2, the sensor control circuit DRV sets the gain of the first amplifier to Low if the first amplifier gain control signal G1 is Low, and outputs the first amplifier if the first amplifier gain control signal G1 is Hi. Is set to Hi. Similarly, if the second amplifier gain control signal G2 is Low, the gain of the second amplifier is set to Low, and if the second amplifier gain control signal G2 is Hi, the gain of the second amplifier is set to Hi. Therefore, the external operation unit (not shown) sets G1 to Low and G2 to L as shown in FIG.
ow. In the case of "HL", G1 is set to Hi and G2 is set to Low as shown in FIG. 7B. In the case of "LH", G1 is set to Low and G2 is set to Hi as shown in FIG. In the case of "HH", G1 is set to H as shown in FIG.
i and G2 are set to Hi. Since G1 is Hi and G2 is Low at time t2 in FIG. 6, the amplification factor in this case is “H”.
L ".

Next, a method of switching the amplification factor of the above-described conventional photoelectric conversion device will be described with reference to flowcharts shown in FIGS. When the release button (not shown) is half-pressed, the focus detection operation shown in FIG. 8 starts. First, # 1 in FIG.
At 00, an initial value is given to the parameter of the charge accumulation operation of the image sensor 3. G1 is an amplification factor of the first amplifier 4 (hereinafter, referred to as a first amplification factor), G2 is an amplification factor of the second amplifier 5 (hereinafter, referred to as a second amplification factor), and T is an image sensor 3.
Where the first amplification rate is Low and the second amplification rate is
The amplification factor is also low and the accumulation time is T0. When each parameter is determined, the sensor control unit 8 causes the image sensor 3 to perform a charge accumulation operation in # 101 based on the parameter, amplifies the output of the image sensor 3 by the first amplifier 4, and further outputs the output to the second amplifier. Amplify with 5. The arithmetic unit 7 converts the amplified signal into an A / D signal
Import after D-conversion.

Next, in step # 102, the peak output of the outputs of the plurality of photoelectric conversion elements of the image sensor 3 is substituted for V for AGC. In step # 103, a focus detection calculation is performed based on the output of the captured image sensor 3, and the defocus amount of the objective lens 1 is obtained. Continue # 104
Then, the lens of the objective lens 1 is driven based on the detected defocus amount. Then, the process proceeds to * 1, and the AGC operation for the next charge accumulation operation is started.

FIG. 9 shows a subroutine of the focus detection AGC. First, in # 200, it is determined whether the peak output V of the image sensor 3 is saturated. Vsat is the saturation level of the image sensor 3. If saturated, the process proceeds to step # 202, where each parameter is set to a predetermined value. For example, “LL” having a low amplification factor is selected, and the accumulation time is set to a small value T1 so that the next charge accumulation operation will not be saturated even for a very bright subject. Then, from * 7, the process exits the AGC subroutine and proceeds to # 101 to start the next accumulation operation.

If it is determined in step # 200 that the output is not saturated, the process proceeds to step # 201, and it is determined whether the peak output V of the image sensor 3 is at an appropriate level. Vcst is AGC
△ Vcst is a predetermined value indicating an allowable range. If Vcst is a large value that is close to the dynamic range of the image sensor output, the brightness of the subject becomes slightly brighter, and the saturation immediately occurs.
If cst is too small, S / N will be worse. If it is determined that the image sensor output is at the appropriate level, the next charge accumulation operation may be performed with the same parameters as the previous time.
Proceed to 101 to start the next accumulation operation. If it is determined that the level is not the appropriate level, the next accumulation time from the previous accumulation time T is determined in # 203.

T = (Vcst / V) · T

Here, in order to keep the response of the focus detection operation from slowing down, when the accumulation time becomes longer to some extent, the gain is switched to a higher one to shorten the accumulation time. In general, when the amplification factor increases, noise is also amplified and the S / N deteriorates. To avoid this, if the accumulation time is shortened to some extent, the amplification factor is switched to a lower one. This operation will be described with reference to FIG. The image sensor 3 is used with the amplifier amplification factor "LL" when the accumulation time is T2 or more and T3 'or less, and when the accumulation time becomes T3' or more, the amplifier amplification factor is switched from "LL" to "HL". Then, the accumulation time is reduced by the increase in the amplification factor. Conversely, if the accumulation time becomes T3 or less at the time of “HL”, the amplifier gain is set to “H”.
Switching from "L" to "LL" to extend the accumulation time by the amount of decrease in the amplification factor.
5 ′ or less, and in the case of “HH”, it is T5 or more and T6 or less. T2 is the shortest accumulation time that can be controlled by the image sensor. Further, T6 is the longest accumulation time set in order to prevent the focus detection operation from becoming unnecessarily long.

In the following, the amplification factors of the first and second amplifiers are switched based on T obtained in # 203 and FIG. In steps # 204, # 205, and # 212, the current combination of the amplification factors of the first and second amplifiers is determined. If "LL", the process proceeds to # 206, and it is determined whether the accumulation time T is equal to or longer than T3 '. In the case of T3 'or more, the amplification factor of the first amplifier is switched from Low to Hi in # 207, and the accumulation time is reduced by the increase of the amplification factor in # 208. And again, # 20
4 and the shortened T is equal to or longer than the accumulation time T3 of “HL” T
It is determined whether it is within the range of 4 'or less. For example, when the brightness of the subject drops rapidly, the accumulation time becomes too long, and it may be necessary to further increase the amplification factor and shorten the accumulation time.

If T is equal to or less than T3 'in # 206, the flow advances to * 2, and the flow advances to # 218 to determine whether T is equal to or less than T2. Since T2 is the shortest accumulation time, if T is T2 or less, #
At 219, T = T2. If T2 or more, it is determined that T obtained in # 203 is appropriate and the AGC subroutine is exited from * 7, and the process returns to # 101 to start the next charge accumulation operation. Similarly, in the case of "HL", the process proceeds to # 209, and if T is equal to or more than T4 ', the gain of the first amplifier is changed from Hi to Low in # 210 and the gain of the second amplifier is Low.
Is switched to Hi, and T is shortened in # 211. T4 '
If it is equal to or more than T3 below, it is determined as appropriate and the process proceeds from # 220 to * 7. If T3 or less, the amplification factor of the first amplifier is set to H in # 221.
Switch from i to Low and extend T at # 222, * 6
And return to # 204.

In the case of "LH", the process proceeds to # 213, where T is T
If it is 5 'or more, the amplification factor of the first amplifier is low at # 214.
Is switched to Hi, and T is reduced in # 215. T5 '
In the following, if it is T4 or more, it is determined as appropriate and the process proceeds from # 223 to * 7. If T4 or less, the amplification factor of the first amplifier is set to L in # 224.
From ow to Hi, the amplification factor of the second amplifier is changed from Hi to Low.
To # 6, extend T in # 225, and go to * 6, # 2
Return to 04. In the case of "HH", the process proceeds to # 216, and if T is T6 or more, T is set to T6 in # 217. If it is equal to or less than T6 and equal to or more than T5, the flow proceeds to # 7 from # 226 as appropriate. T
If it is 5 or less, the amplification factor of the first amplifier is switched from Hi to Low in # 227, T is extended in # 228, the process proceeds to * 6, and returns to # 204.

Once the optimum amplifier amplification factor and accumulation time for the next charge accumulation operation have been obtained as described above, the program returns from step * 7 to # 101 through the AGC subroutine to start the next charge accumulation operation.

[0023]

In a conventional photoelectric conversion device and an automatic focusing camera incorporating the photoelectric conversion device,
In order to control the amplification factor of an amplifier (amplifier), one control signal terminal must be provided for one amplifier on the sensor chip, and there is a disadvantage that current consumption is large and external wiring is complicated. .

An object of the present invention is to provide a photoelectric conversion device and an automatic focusing camera in which the control method of the amplification factor of each amplifier is simplified.

[0025]

[Means for Solving the Problems]

(1) The invention according to claim 1 is a charge storage type photoelectric conversion element array comprising a plurality of charge storage type photoelectric conversion elements for storing electric charges according to light intensity, and each photoelectric conversion element of the charge storage type photoelectric conversion element array A transfer circuit for sequentially outputting the accumulated charges of
And an amplifier circuit for amplifying the output signal of the transfer circuit, receiving a charge accumulation start command, starting charge accumulation in the charge accumulation type photoelectric conversion element array, and issuing a charge accumulation end command. A charge accumulation control circuit for receiving and terminating charge accumulation in the charge accumulation type photoelectric conversion element array; a first amplifier and a second amplifier based on an amplification factor control signal when a charge accumulation start command is received and a charge accumulation end signal is received; And a gain control circuit for setting the gain of the amplifier. (2) The photoelectric conversion device according to claim 2, wherein the amplification factor control circuit sets the amplification factor of the first amplifier based on the level of the amplification factor control signal at the time of receiving the charge accumulation start command, and receives the charge accumulation termination command. The amplification factor of the second amplifier is set based on the level of the amplification factor control signal at that time. (3) The photoelectric conversion device according to claim 3, wherein a focus detection optical system that guides a light beam from a subject that has passed through the imaging optical system to the photoelectric conversion device, and a focus adjustment state of the imaging optical system based on an output signal of the amplifier circuit. A focus detection arithmetic circuit for detecting, a drive control circuit for driving and controlling the photographing optical system based on the focus adjustment state detected by the focus detection arithmetic circuit, and a charge storage type photoelectric conversion element array based on an output signal of the amplifier circuit. A photoelectric conversion operation circuit for calculating a charge accumulation time and an amplification factor of an amplifier circuit; a charge accumulation start command and a charge accumulation end signal based on the charge accumulation time calculated by the photoelectric conversion operation circuit; And a photoelectric conversion control circuit that outputs an amplification factor control signal at the time of outputting a charge accumulation start command and at the time of outputting a charge accumulation termination command based on the amplification factor calculated by the above. (4) The automatic focusing camera according to claim 4, wherein the photoelectric conversion control circuit outputs a gain control signal having a level corresponding to the gain of the first amplifier when the charge accumulation start command is output,
At the time of receiving the charge accumulation end command, an amplification factor control signal having a level corresponding to the amplification factor of the second amplifier is output.

[0026]

FIG. 1 shows a configuration of a sensor chip according to an embodiment. The same components as those shown in FIG. 5 are denoted by the same reference numerals, and the description will focus on the differences. Gx is a first and second amplifier amplification factor control signal, which is supplied from an external calculation unit (not shown) to the sensor control circuit DRV.

FIG. 2 is a time chart showing the operation of the embodiment. An operation clock CL is transmitted to the transfer register SR.
K1 and CLK2 are supplied, and the transfer register SR constantly performs a transfer operation. The period from time t1 to t2 when the accumulation time control signal Tm is Hi is the charge accumulation time of the charge accumulation type photoelectric conversion element array. Until time t1, the control signal OGP is Hi and the overflow gate OVG is open, so that the charges generated in the charge storage type photoelectric conversion element array are not stored in the charge storage type photoelectric conversion element array, but are sent to the overflow drain OVD.

When the storage time control signal Tm that has become Hi at time t1 is supplied to the sensor control circuit DRV, the sensor control circuit DRV sets the control signal OGP to Low, closes the overflow gate OVG, and causes the charge storage type photoelectric conversion element. Initiate charge storage in the array. In addition, the sensor control circuit DRV determines whether the first and second amplifier gain control signals Gx are in the Hi / Low state at time t1.
The amplification factor of the first amplifier is switched. At time t2, when the operation unit (not shown) sets the accumulation time control signal Tm to Low, the sensor control circuit DRV sets the control signal SGP to Hi to open the transfer gate SG, and the electric charge accumulated in the charge accumulation type photoelectric conversion element array. To the transfer register SR. Further, the sensor control circuit DRV performs the first control at the time t2.
And the amplification factor of the second amplifier is switched based on the Hi / Low state of the second amplifier amplification factor control signal Gx. At time t3 when a predetermined time has elapsed from time t2, the sensor control circuit DRV sets SGP to Low and sets the transfer gate SG.
Is closed, the control signal OGP is set to Hi, the overflow gate OVG is opened, and the charge generated in the charge storage type photoelectric conversion element array is transferred to the overflow drain OVD again.

On the other hand, the electric charge transferred by the transfer register SR is converted into a voltage, amplified by the first amplifier AMP1 and the second amplifier AMP2, and converted into a signal Vout at time t.
4 After time t4, a signal corresponding to the amount of charge accumulated in PE1, PE2,... PEn appears every clock cycle as a time-series signal.

The sensor control circuit DRV operates at time t.
In 1, if the first and second amplifier gain control signals Gx are Low, the gain of the first amplifier is Low, and if the first and second amplifier gain control signals Gx are Hi, the gain of the first amplifier is Hi. To Also, the sensor control circuit DR
V sets the amplification factor of the second amplifier to Low when the first and second amplifier amplification factor control signals Gx are Low at time t2.
If the first and second amplifier gain control signals Gx are Hi, the gain of the second amplifier is set to Hi. Accordingly, when “LL” is set, the external operation unit (not shown) sets Gx to Low throughout as shown in FIG. 3A. FIG. 3 for "HL"
As shown in (b), Gx is Hi at time t1 and time t2.
Let's make it Low. In the case of "LH", Gx is set to Low at time t1 and Hi at time t2 as shown in FIG. In the case of "HH", Gx is always set to Hi as shown in FIG. In the present embodiment, at time t1 in FIG.
And the second amplifier gain control signal Gx is Hi at time t2
Since it is Low, the amplification factor is “HL”.

In the configuration of the above embodiment of the present invention,
The charge storage type photoelectric conversion element arrays PE1 to PEn indicate charge storage type photoelectric conversion element columns, the transfer register SG indicates a transfer circuit, the first amplifier AMP1 indicates the first amplifier, the second amplifier AMP2 indicates the second amplifier, First amplifier AMP1 and second amplifier
The amplifier AMP2 converts the amplifier circuit into the sensor control unit 8 (DR
V) is a charge accumulation control circuit and an amplification factor control circuit, the focus detection optical system 2 is a focus detection optical system, the calculation unit 7 is a focus detection calculation circuit, a photoelectric conversion calculation circuit and a photoelectric conversion control circuit, and the drive control unit 10 Constitute a drive control circuit.

[0032]

As described above, according to the present invention, the amplification factors of the first amplifier and the second amplifier are determined based on the amplification control signals when the charge accumulation start command is received and when the charge accumulation end signal is received. Since it is set, there is no need to provide and connect an amplification factor control signal terminal for each amplifier in order to control the amplification factor of the amplifier, which simplifies external wiring and saves current consumption. it can.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a sensor chip according to an embodiment.

FIG. 2 is a time chart illustrating signals of the photoelectric conversion device according to the embodiment;

FIG. 3 is a diagram illustrating a combination of control signals according to an embodiment.

FIG. 4 is a diagram illustrating a configuration of an automatic focus detection device including a photoelectric conversion device.

FIG. 5 is a diagram showing a configuration of a conventional sensor chip.

FIG. 6 is a time chart showing signals of a conventional photoelectric conversion device.

FIG. 7 is a diagram illustrating a conventional combination of control signals.

FIG. 8 is a flowchart illustrating an automatic focus detection operation.

FIG. 9 is a flowchart showing an AGC operation.

FIG. 10 is a diagram illustrating switching of the amplifier gain.

FIG. 11 is a diagram illustrating AGC.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Objective lens 2 Focus detection optical system 3 Image sensor 4 1st amplifier 5 2nd amplifier 6 A / D conversion part 7 Operation part 8 Sensor control part 9 Sensor chip 10 Drive control part 11 Motor PE1, PE2, ..., PEn charge Storage type photoelectric conversion element OVD overflow drain OVG overflow gate SR transfer register SG transfer gate

Claims (4)

[Claims] 1. A charge accumulation type photoelectric conversion element array comprising a plurality of charge accumulation type photoelectric conversion elements for accumulating electric charges according to light intensity, and a charge accumulated in each photoelectric conversion element of the charge accumulation type photoelectric conversion element string. A transfer circuit for sequentially outputting a signal; an amplifier circuit having a first amplifier and a second amplifier for amplifying an output signal of the transfer circuit; and a charge storage type photoelectric conversion element array receiving a charge storage start command. A charge accumulation control circuit that starts the charge accumulation of the charge accumulation termination command and terminates the charge accumulation of the charge accumulation type photoelectric conversion element array, and receives the charge accumulation start command and the charge accumulation end command. And a gain control circuit for setting a gain of the first amplifier and a gain of the second amplifier based on the gain control signal. 2. The photoelectric conversion device according to claim 1, wherein the amplification factor control circuit adjusts an amplification factor of the first amplifier based on a level of the amplification factor control signal when the charge accumulation start command is received. A photoelectric conversion device, wherein the amplification factor of the second amplifier is set based on a level of the amplification factor control signal when the charge accumulation termination command is received. 3. The photoelectric conversion device according to claim 1 or 2, a focus detection optical system that guides a light beam from a subject that has passed through a photographing optical system to the photoelectric conversion device, and an output signal of the amplification circuit. A focus detection arithmetic circuit that detects a focus adjustment state of the imaging optical system based on the drive signal; a drive control circuit that drives and controls the imaging optical system based on the focus adjustment state detected by the focus detection arithmetic circuit; A photoelectric conversion operation circuit that calculates the charge accumulation time of the charge accumulation type photoelectric conversion element array and the amplification factor of the amplifier circuit based on the output signal of the photoelectric conversion element circuit; and the charge based on the charge accumulation time calculated by the photoelectric conversion operation circuit. A charge start command and the charge accumulation end command are output, and the charge accumulation start command is output based on the amplification factor calculated by the photoelectric conversion operation circuit, and the charge Automatic focusing camera comprising: a photoelectric conversion control circuit for outputting the gain control signal at the product end command output. 4. The automatic focusing camera according to claim 3, wherein the photoelectric conversion control circuit outputs the gain control signal having a level corresponding to the gain of the first amplifier when the charge accumulation start command is output. And outputting the gain control signal at a level corresponding to the gain of the second amplifier upon receiving the charge accumulation end command.