JP2001324669A - Automatic focusing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic focusing device capable of controlling the integration time of an optimum integration type light receiving sensor and realizing focusing operation to whatever subject it is because the device has no subject hard to be brought into focus. SOLUTION: The brightness and darkness of the subject is decided by a brightness and darkness decision circuit 12 based on the result of photometry. In the case of deciding that it is dark, a 2nd area designation mode being characteristic is performed. By successively selecting areas B, C and D out of the areas divided into five of the integration type light receiving sensor and performing pre-integration, respective monitor data B, C and D are acquired. In such a case, after setting sensor sensitivity to high sensitivity, integrating operation is performed for 1 msec, and a monitor signal obtained when 1 msec elapses after starting the integrating operation is acquired. Then, the data equivalent to the darkest data is selected from the obtained monitor data B, C and D. In such processing, the selection is equal to selecting the darkest area. Thereafter, the selected area is set, and integration, the calculation of distance information, the adjustment of a focal distance and photographing (exposure) are performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic focusing device such as a camera, and more particularly, to a monitor signal detecting area for integration time control in a passive type automatic focusing device using an integral type light receiving sensor. Regarding the designation method.

[0002]

2. Description of the Related Art In general, cameras are equipped with various types of automatic focus adjustment devices. In particular, passive type automatic focus adjustment devices are characterized by a short focusing time.
Even in a scene where the time lag is not preferable, it is possible to sufficiently cope with the situation, that is, there is an advantage that the distance to the subject can be measured at high speed and the automatic focus adjustment can be performed.

However, in such a passive type automatic focusing apparatus, since an integrating type light receiving sensor is used, the integration time must be appropriately controlled in accordance with the brightness of the subject. If the integration time control is not properly performed, the subject image signal may hardly be obtained or may be saturated, and accurate focus adjustment may not be performed.

Therefore, usually, a specific area of the integral type light receiving sensor is used as a monitor signal detection area for integration time control.
Alternatively, an integration time control has been performed in which a dedicated light receiving sensor for detecting a monitor signal is provided near the integration type light receiving sensor and the integration is terminated when the monitor signal reaches a predetermined level.

As this type of focus detection device, there is a focus detection device advertised in Japanese Patent Publication No. 7-75401. This focus detection device is, as described in the document of this publication, an automatic focus adjustment device in which the area of the subject image signal of the integral type light receiving sensor used for focus adjustment is variable, and A technique of matching an area with a monitor signal detection area has been conventionally known.

As described in the above-mentioned prior art and other prior arts, many proposals have been made for the purpose of optimizing the integration time control of the integral type light receiving sensor. Was well known.

[0007]

However, the above-mentioned prior art describes a technique devised up to the point where the subject is analyzed and the integration time control of the integral type light receiving sensor is optimized for each subject. Not. In other words, in the related art, the subject with the night view as the background is a weak point, and the integration time control of the integration type light receiving sensor cannot be appropriately performed. In the related art, when acquiring a subject image signal of a subject with a night view as a background, that is, when performing integration time control of the integration type light receiving sensor, a monitor signal detection area becomes a problem, and a bright portion of the background is a leading part of integration time control. Therefore, it is impossible to control the integration time of the integration type light receiving sensor suitable for the main subject. As a result, the subject image signal of the main subject is crushed and hardly obtained. This is because the monitor signal detection area extends not only to the main subject but also to the night scene as the background. Ideally, the monitor signal detection area is desirably an area that is substantially equal to the main subject. As described above, in the related art, when the background of the subject is a night scene, the integration time control cannot be optimized, and as a result, there is a problem in that the captured image of the high-definition subject cannot be obtained. The problem is how to properly adjust the focus of a subject against the background of a night view, which is a weak point.

Accordingly, the present invention has been made in view of the above-mentioned problems, and has an automatic focus adjusting device capable of performing optimal integration time control and focus adjusting operation of an integral type light receiving sensor for any subject without a poor subject. The purpose is to provide.

[0009]

According to a first aspect of the present invention, there is provided an automatic focusing apparatus which focuses on at least one pair of integral type light receiving sensors based on a subject image signal obtained by receiving light from the subject. In an automatic focus adjustment device for performing adjustment, a photometric unit that measures the luminance of a subject, a light / dark determining unit that compares the output of the photometric unit with a predetermined value to determine the brightness of the subject, and the integration type light receiving unit. An area storing means for storing a plurality of area specifying information for designating a predetermined area in a light receiving area of the sensor; and a plurality of area specifying information stored in the area storing means according to a determination result of the light / dark determining means. Area specifying means for extracting at least one area specifying information and specifying a predetermined area to be integrated by the integration type light receiving sensor; A monitor signal extracting means for extracting the largest of the amounts and is characterized by comprising a.

According to the first aspect of the present invention, in the automatic focusing apparatus having the above-mentioned configuration, the plurality of area designations stored in the area storage means by the area designation means in accordance with the judgment result of the light / dark judgment means. By extracting at least one area designation information from the information, it is possible to designate a predetermined area to be integrated by the integration type light receiving sensor, and by the monitor signal output means, the area within the area designated by the area designation means can be designated. Since the largest integration amount can be extracted, for example, even when a scene such as a night scene is taken as a background, integration control can be performed based on a dark place, and as a result, the main subject can be correctly focused. Adjustment can be performed.

According to a second aspect of the present invention, in the automatic focusing apparatus according to the first aspect, when the brightness of the subject is determined to be bright by the brightness determining means, the area is stored. A first method for selecting and specifying at least one of the plurality of area specifying information stored in the means;
If the brightness of the subject is determined to be dark by the brightness / darkness determination means, a plurality of pieces of area designation information stored in the area storage means are selected one by one and sequentially determined for each area. A region designation mode setting means for performing pre-integration of time and setting a second region designation mode for selecting and designating region designation information of the darkest region based on a monitor signal for each region acquired at this time; It is characterized by further comprising

According to the second aspect of the present invention, when the brightness of the subject is determined to be bright by the brightness determining means, the first
Is performed, and conversely, if it is determined that the scene is dark, the second region specifying mode is executed. Therefore, even in a scene such as a night scene as a background, a dark place is searched by pre-integration, However, the integral control can be performed on the basis of the reference, that is, the integral control can be performed while ignoring the night scene of the background. Therefore, it is possible to obtain an image signal of a subject having a different luminance level between the background and the person. Therefore, similarly to the invention of the first aspect, it is possible to correctly perform focus adjustment on the main subject even in a scene with a night view as a background.

According to a third aspect of the present invention, in the automatic focusing apparatus according to the second aspect, the area designation mode setting means performs the pre-integration.
The method is characterized in that the integration type light receiving sensor is set with high sensitivity.

According to the third aspect of the present invention, the same operation as in the first and second aspects of the present invention is obtained, and the same effect is obtained. In addition, the area designation mode setting means performs the pre-integration. In this case, by setting the integration type light receiving sensor with high sensitivity, the focus adjustment function of the main subject can be further improved.

[0015]

Embodiments of the present invention will be described with reference to the drawings. 1 to 6 show an embodiment of an automatic focusing device according to the present invention. FIG. 1 is a block diagram showing a configuration example of the automatic focusing device, and FIG. 2 is used in the device shown in FIG. FIG. 3 is a view showing a finder field of view of a camera to which the automatic focusing apparatus of FIG. 1 is applied, and FIG. 4 is a model diagram showing a bright and dark subject, respectively. FIG. 5 shows FIG.
Flowchart showing a control operation example by the CPU shown in FIG.
FIG. 6 is an explanatory diagram showing each subject having different subject brightness and subject image signals corresponding to the integration control.

(Construction) As shown in FIG. 1, the automatic focusing apparatus according to the present embodiment has at least a pair of lenses 1a and 1a.
This is an automatic focus adjustment device that receives light from the subject by 1b and the integration type light receiving sensors 2a and 2b, acquires the subject image signal by the integration circuit 3, and adjusts the focus of the camera.

A specific configuration will be described. The automatic focusing apparatus according to the present embodiment includes a distance measuring block including at least a pair of lenses 1a and 1b and an AFIC 9 as shown in FIG. A photometric block including a photometric sensor 10 and a photometric circuit 11, a storage block for storing data necessary for automatic focus adjustment, and a memory block (not shown) necessary for photographing by a camera equipped with the device. It controls the photographing mechanism block and the entire apparatus and camera, and includes a control block mainly composed of the CPU 16.

The 1FIC 9 included in the distance measuring block includes an integral type light receiving sensor 2a, 2b for receiving light from a subject through at least a pair of lenses 1a, 1b, an integrating circuit 3, and a resetting circuit for resetting the integrating circuit. An integration reset circuit 4, an integration data output circuit 5 for outputting a subject image signal, a monitor signal extraction circuit 6a for extracting a monitor signal for performing integration control of the integration circuit 3, and outputting a monitor signal. , A monitor signal detector 6 including a monitor signal output circuit 7a, a sequence controller & interface circuit 8, and the like.

The sequence controller & interface circuit 8 controls the integration circuit 3 and all other peripheral circuits (integration reset circuit 4, integration data output circuit 5, monitor signal detector 6).

The monitor signal output circuit 7a of the monitor signal detection section 6 supplies a monitor signal to each of the integration time control section 13 and the area designation section 14 in the CPU 16 as a control block.

On the other hand, in the photometric block, the photometric sensor 10 receives light from the subject through the lens 1c,
The received light data is given to the photometric circuit 11. The photometry circuit 11 performs photometry based on the received light data, and supplies the photometry result to a light / dark determination circuit 12 in the CPU 16.

A storage block for storing and storing data is mainly constituted by an EEPROM 17 as a storage area means. Of course, there is no problem even with a storage medium other than the EEPROM, and it goes without saying that many variations are possible.

The control block mainly comprises a CPU 16 for controlling the apparatus and the entire camera.
Reference numeral 6 includes, for example, a circuit unit necessary for executing a function that is a feature of the present embodiment in addition to a function of controlling the entire apparatus and the camera.

For example, as shown in FIG.
A light / dark judgment circuit 12 for judging the brightness of a subject based on the output of the photometry circuit 11, an integration time control unit 13 for controlling the integration time of the integration circuit 3 of the AFIC 9, and a monitor signal for performing the integration control are provided. It is configured to include a monitor area specifying unit 14 for specifying an area to be output, a sequence controller & interface circuit 15 which is a core of the CPU 16, and the like.

The sequence controller & interface circuit 15 has an RA for storing integrated data therein.
M and arithmetic circuits, and by using these circuits, mainly read control and write control of data in the EEPROM 17, communication control of the AFIC 9 for the sequence controller & interface 8, control control, and monitor signals for the area designating section 14. The control for designating the area for outputting is performed.

It should be noted that the sequence controller & interface circuit 15 is supplied with the judgment result by the plan judgment circuit 12. The sequence controller & interface circuit 15 performs various controls at a timing based on the integration time control by the integration time control unit 13.

By the way, in the present embodiment, in order to perform the characteristic operation control by the automatic focusing device having the above-mentioned configuration, the pair of integral type light receiving sensors 2a and 2b are preset.

That is, in the present embodiment, as shown in FIG. 2, the pair of integral type light receiving sensors 2a and 2b are divided into, for example, five regions, and regions A, B, C, D, and
Set to be E. On the other hand, information on these five areas is stored and held in the area storage means of the EEPROM 17. The divided area of the integral type light receiving sensor is not limited to five,
It may be set so as to be divided into other n pieces. In response to this, information on the n areas is stored and held in the area storage means of the EEPROM 17.

When the automatic focusing device of the present embodiment is adapted to a camera, the positional relationship between the field of view of the integral type light receiving sensor and the field of view of the photometric sensor with respect to the viewfinder field or the photographing range is as shown in FIG. Become.

(Operation) Next, the control operation of the automatic focusing apparatus according to the present embodiment will be described in detail with reference to FIG. Note that a case will be described in which, for example, the subject shown in FIG. 4 is photographed using the automatic focusing apparatus according to the present embodiment. FIG. (B) shows the subject when trying to shoot at night.

Now, it is assumed that the power switch (not shown) of the camera equipped with the automatic focusing device shown in FIG. 1 is turned on or the battery is inserted to turn on the power. Then, the CPU 16 is activated to activate the main routine (power-on reset routine of the camera) of FIG.

The CPU 16 first performs an initialization operation inside the camera in the process of step S100. The initialization includes all initialization operations such as the initialization of the electrical system including the initialization of the CPU 16 and the initialization of the mechanism.

Then, the CPU 16 proceeds to the next step S1.
A shooting standby loop composed of the processes 01 to 103 is executed, and is repeatedly executed until shooting is executed. That is, various processes 1 are performed in the process of step S101, and in the subsequent determination process of step S102, whether or not the release switch is pressed is determined. If the release switch is pressed, the process proceeds to step S104. Subsequent step S
Various processes 2 are executed in the process of 103, and the process returns to the step S101.

Note that step S101 and step S101
Processes 1 and 2 of 103 are a switch status detection process and LC
Most of the control processing of display elements such as D is performed. Further, the determination processing in step 102 is one of the switch state detections, and detects not only the release switch being pressed but also the state of the release switch. For example, 1RSW and 2RS
In the case of a two-stage release switch with W, it is possible to detect the state of these switches.

If the release switch is pressed (turned on) in the judgment processing of step S102, the CPU 16
Exits the above-described shooting standby loop and proceeds to the next step S1.
Control is performed so that photometry is performed in the process of step 04. In the photometric operation in this case, the lens 1c and the photometric sensor 1 shown in FIG.
0 and a photometric block configured to include the photometric circuit 11.

Thereafter, when the photometric operation is completed, the CPU 1
6 is a determination process of the subsequent step S104, in which the brightness of the subject is determined. That is, the light / dark judgment is performed by the light / dark judgment circuit 12 in the CPU 16.
Reference numeral 2 compares the output of the photometric circuit 11 with data indicating a predetermined luminance to determine whether the subject is bright or dark.
In this case, the data indicating the predetermined luminance may be a ROM fixed value of the CPU 16, but it is convenient to store the data as rewritable nonvolatile data in the EEPROM 17.

If the CPU 16 determines that the subject is bright in the light / dark determination processing in step S105, the CPU 16 executes a process shift process of step S106. Conversely, if the subject is determined to be dark, the present invention is executed. Is controlled so as to execute the process transition process of step S115, which is a feature.

First, a description will be given of a process performed when the brightness of the subject is determined to be bright by the determination of the light / dark determination circuit 12.

For example, when an object of a bright scene as shown in FIG. 4A is photographed by the camera, the automatic focusing apparatus of the present embodiment performs processing on a bright object in substantially the same manner as in the prior art. Will be implemented. That is, the CPU 16 proceeds to step S19.
6 and B, C, and B in the areas shown in FIG.
The three areas D are designated, and this is set as a first area designation mode. However, the first area designation mode is not limited to the above, and many modifications can be considered. For example, A, B, C, D, and E of the entire area may be specified, or only the area C may be specified. In addition, the entire area may be designated in the multi-AF mode, and only the area C may be designated in the spot AF mode, in connection with the mode of the camera. Further, the brightness of the subject may be divided into three levels of light, normal, and dark, and the whole area may be specified in the case of light, and only the area C may be specified in the normal case.

Thereafter, the sequence controller & interface circuit 15 in the CPU 16 stores the area data corresponding to the specified area in the EEP as the area storage means.
By selectively extracting from the ROM 17 and transferring it to the area specifying unit 14 in the CPU 16 and setting it in the monitor signal extracting circuit 6 via the sequence controller & interface circuit 8 in the AFIC 9, the monitor signal is extracted. The setting of the area is executed.

Then, the CPU 16 proceeds to the next step S1.
The process shifts to step 07, where the integration operation is executed.
The integration operation in this case is performed first by the integration reset circuit 4
Then, the integration is reset once and the integration is started.
During the integration operation, the monitor signal extraction circuit 6 outputs a monitor signal to the integration time control unit 13 in the CPU 16 through the monitor signal output circuit 7.

The integration time control unit 13 monitors a monitor signal that changes in real time and is output in real time, for example, during the integration operation, measures the time required for integration to progress to half of the integration dynamic range, and further measures the time measured. The integration control is performed such that the integration is continuously performed for the same time. Note that many variations of the integration control method are conceivable, and it goes without saying that the present invention is not limited to the above. For example,
An integration control method or the like may be considered in which the monitoring of the monitor signal is continued until the monitor signal reaches a predetermined level, and the integration is terminated when the monitor signal reaches the predetermined level.

Thereafter, the CPU 16 proceeds to the next step S1.
In step 08, the image signal of the subject is obtained from the AFIC 9 via the integration data output circuit 5. In this case, the CPU 1
6 sequence controller & interface circuit 1
5 contains R for storing integral data as described above.
An image signal (integrated data) of the subject is temporarily stored in a RAM or the like.

Then, the CPU 16 proceeds to the next step S1.
In the process 09, the correlation calculation process is performed for each ranging area under the control of the sequence controller & interface circuit 15. . Since the correlation calculation in this case is a known technique, the description is omitted for simplification of the description. Also, nothing has been described so far about the ranging area,
Most simply, the five regions A, B, C,
D and E may each be five ranging areas. As an embodiment of the present invention, the image shift amounts of the subject image signals in the five regions (hereinafter, referred to as the distance measurement areas) are defined as the five regions.
(Referred to as a phase difference). However, it is not necessary that the ranging area and the detection area of the monitor signal coincide with each other, and the area specified by the area specifying unit 14 and the ranging area may be independent of each other.

Next, the CPU 16 proceeds to step S1.
The process proceeds to step S10, and the nearest selection is performed in the processing. The closest selection means to select the maximum value indicating the closest from the phase differences obtained in the process of step S109, and select the ranging area where the phase difference is the maximum value. afterwards,
The process moves to step S111.

In the process of step S111, the CPU 16 calculates the distance information of the subject from the phase difference data of the ranging area selected in the process of step S110.

In this case, when the subject is bright, that is, in the scene of FIG. 4A, the subject image signal shown in FIG. 6A is obtained, and the distance information of the subject is correctly calculated as described above. It is possible to That is, even when the subject is bright, the automatic focus adjustment device of the related art can perform the focus adjustment correctly.

Thereafter, the CPU 16 proceeds to step S
The process proceeds to step 112, where the focus adjustment is performed by driving and controlling the focus adjustment optical system in the photographing mechanism block (not shown) in the process, and the process proceeds to step S113.

In the process of step S113, the CPU 16
Drives and controls a photographing mechanism block (not shown) to execute photographing (exposure), and then drives and controls a film driving circuit (not shown) in the subsequent process of step S114 to thereby control one frame of the film. Is carried out. In this way, the photographing operation is completed, and thereafter, in order to wait for the next photographing, the process returns to step S101, a photographing standby loop is executed, and a photographing standby state is set.

Next, in the process of step S102,
A description will be given of a process that is a feature of the present embodiment when it is determined that the subject luminance is dark based on the determination by the brightness determination circuit 12.

For example, when an object of a dark scene as shown in FIG. 4B is photographed by the camera, the conventional automatic focusing device performs the same processing irrespective of the brightness of the object. Is a signal having a level as shown in FIG. In other words, the signal based on the background is bright, but the signal based on the important person is dark. This is because the integration is controlled based on the brightest place. That is, since the integral control is performed on the light source with a bright background, the person who is the main subject is darkened and no image signal can be obtained. Therefore, in the automatic focusing device of the related art, when the background is a night scene, it is difficult to focus on the background by adjusting the focus on the background.

Therefore, in the present embodiment, the second area designation mode, which is a feature of the present invention, is executed. That is,
The CPU 16 shifts the processing to step S115, specifies the area B in the area shown in FIG. 2 in the processing, performs the first pre-integration in the subsequent processing in step S116, and converts the monitor data B get. In this case, in the pre-integration performed in the present embodiment, an integration operation is performed for 1 msec after the sensor sensitivity is set to a high sensitivity under the control of the CPU 16, and a monitor signal 1 msec after the start of integration is obtained. Is controlled.

Thereafter, the CPU 16 proceeds to step S
The process then proceeds to step 117, where the area C is designated from the areas shown in FIG. 2 in the processing, the second pre-integration is performed in the processing of the subsequent step S118, monitor data C is obtained, and the processing is continued. The process moves to S119.

In step S119, the CPU 16 specifies the area D in the area shown in FIG. 2 in the processing, and performs the third pre-integration in the subsequent processing in step S120.
Obtain monitor data D and continue the process in step S121
Move to

Then, the CPU 16 proceeds to step S121.
, The monitor data B,
Data corresponding to the darkest data is selected from C and D. In other words, this processing is equivalent to selecting the darkest area.

Thereafter, the CPU 16 proceeds to the next step S1.
In the process of step S22, after designating and setting the area selected in the process of step S121, the process proceeds to step S10.
7 and the process of step S107 is executed. In this way, the integration processing, the distance information calculation processing, the focus adjustment processing, and the photographing (exposure) are performed as described above, and after the photographing operation is completed, the apparatus enters a photographing standby state for performing the next photographing.

As described above, if the light / dark judgment of the subject and the second area designation mode, which are the features of the present invention, are executed,
Even in a scene where the night view is a background, a dark place can be searched for by pre-integration, and the integral control can be performed based on the dark place. In other words, the integration control can be performed while ignoring the background night view, so that the image signal of the subject is
As shown in (c), a background and a person having different luminance levels are obtained. Therefore, it is possible to correctly adjust the focus of the main subject even in a scene with a night view as a background, which is difficult in the related art.

(Effects) Therefore, according to the present embodiment, when a scene such as a night scene is photographed as a background, integration control can be performed while ignoring the background night scene. This makes it possible to obtain a proper image signal, and as a result, it is possible to correctly adjust the focus of the main subject even in a scene with a night view as a background.

[0059]

As described above, according to the present invention, it is possible to provide an automatic focus adjusting device which has no weak subject, and always enables optimal integration time control and focus adjusting operation of the integral type light receiving sensor. Become. Therefore, focusing can be performed with high accuracy for any subject without fail, and mounting the automatic focusing device on a camera greatly contributes to improvement in camera performance.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an automatic focusing apparatus according to the present invention, and showing a configuration example of the apparatus.

FIG. 2 is an explanatory diagram showing an integral type light receiving sensor used in the apparatus of FIG. 1 and its area division.

FIG. 3 is a view showing a finder field of view of a camera to which the automatic focusing apparatus of FIG. 1 is applied;

FIG. 4 is a model diagram showing a bright subject and a dark subject, respectively.

FIG. 5 is a flowchart showing an example of a control operation by the CPU shown in FIG. 1;

FIG. 6 is an explanatory diagram showing objects having different object luminances and object image signals corresponding to integral control.

[Description of Signs] 1a, 1b, 1c: lens, 2a, 2b: integral light receiving sensor, 3: integral circuit, 4: integral reset circuit, 5: integral data output circuit, 6: monitor signal detection unit, 6a: monitor Signal extraction circuit, 7a Monitor signal output circuit, 8 Sequence controller & interface circuit, 9 AFIC, 10 Photometry sensor, 11 Photometry circuit, 12 Brightness / darkness determination circuit, 13 Integration time control unit, 14 Area Designation unit, 15: Sequence controller & interface circuit, 16: CPU (control means), 17: EEPROM.

Claims (3)

[Claims] 1. An automatic focus adjustment device that performs focus adjustment based on a subject image signal obtained by receiving light from a subject by at least a pair of integral type light receiving sensors, wherein: a photometric unit that measures subject brightness; Brightness / darkness determining means for comparing the output of the photometric means with a predetermined value to determine the brightness of the subject; and storing a plurality of area designation information for designating a predetermined area among the light receiving areas of the integral type light receiving sensor. Area extracting means for extracting at least one area specifying information from the plurality of area specifying information stored in the area storing means in accordance with the judgment result of the light / dark judging means, and integrating the extracted information by the integrating type light receiving sensor. Area designating means for designating a predetermined area, and monitor signal extracting means for extracting the largest one of the integration amounts in the area designated by the area designating means, An automatic focusing device, comprising: 2. A method according to claim 1, wherein said first determining means selects and designates at least one of a plurality of pieces of area designation information stored in said area storage means when said brightness determining means determines that said subject brightness is bright. An area designation mode, and when the brightness of the object is determined to be dark by the light / dark determination means, a plurality of area designation information stored in the area storage means are selected one by one and sequentially for a predetermined time for each area. And a second area specification mode for selecting and specifying the area specification information of the darkest area based on the monitor signal obtained for each area obtained at this time. The automatic focusing device according to claim 1, wherein the automatic focusing device is provided. 3. The automatic focusing apparatus according to claim 2, wherein the area designation mode setting means sets the integral type light receiving sensor with high sensitivity when performing the pre-integration.