JP2013016904A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of a giant white spot due to blooming phenomenon regardless of imaging conditions.SOLUTION: The imaging apparatus comprises an imaging element having a photoelectric conversion section which generates charges depending on the amount of incident light and stores the charges thus generated, discharge means for discharging the charges thus stored when the charges during storing exceeds a predetermined storage amount, first setting means for setting the exposure time of the imaging element, and switching means for switching the predetermined storage amount depending on an exposure time set by the first setting means. The switching means sets the predetermined storage amount to a first storage amount when the exposure time is set to a first exposure time, and sets the predetermined storage amount to a second storage amount larger than the first storage amount when the exposure time is set to a second exposure time shorter than the first exposure time.

Description

  The present invention relates to an imaging apparatus.

  Conventionally, a photoelectric conversion element having a function of discharging charges accumulated excessively by an overflow drain structure to a substrate is known (for example, Patent Document 1).

Japanese Patent Laid-Open No. 11-87680

  However, depending on the photographing conditions, there is a problem that a huge white spot is generated in the photographed image due to the blooming phenomenon in which the excessively accumulated charge leaks to the adjacent pixels.

An image pickup apparatus according to a first aspect of the present invention includes an image pickup device that includes a photoelectric conversion unit that generates charges according to the amount of incident light and accumulates the generated charges, and a charge that is being accumulated exceeds a predetermined accumulation amount. And discharging means for discharging the accumulated charge, first setting means for setting the exposure time of the image sensor, and switching means for switching a predetermined accumulation amount according to the exposure time set by the first setting means. The switching means sets the predetermined accumulation amount to the first accumulation amount when the exposure time is set to the first exposure time, and sets the exposure time to the second exposure time shorter than the first exposure time. In this case, the predetermined accumulation amount is set to a second accumulation amount that is larger than the first accumulation amount.
An image pickup apparatus according to a second aspect of the present invention is an image pickup device that includes a photoelectric conversion unit that generates charges according to the amount of incident light and stores the generated charges, and a charge that is being stored exceeds a predetermined amount of storage. In addition, the discharge unit for discharging the accumulated electric charge, the first setting unit for setting the exposure time of the image sensor, the second setting unit for setting the imaging sensitivity of the image sensor, and the predetermined accumulation amount are set to the first setting. Switching means for switching based on the exposure time set by the means and the imaging sensitivity set by the second setting means, and the switching means sets the imaging sensitivity to the lowest sensitivity and sets the exposure time to a long second Or if the imaging sensitivity is set to a value other than the minimum sensitivity, the predetermined accumulation amount is set to the first accumulation amount, the imaging sensitivity is set to the minimum sensitivity, and the exposure time is set to a short second. If it is And setting the second accumulation amount greater than the first accumulation amount.
According to an eighth aspect of the present invention, there is provided an imaging device that generates an electric charge according to the amount of incident light, has an photoelectric conversion unit that accumulates the generated electric charge, and the accumulated electric charge exceeds a predetermined accumulated amount A discharge unit that discharges the accumulated charge, a setting unit that sets an exposure time of the image sensor, and a switching unit that switches a predetermined accumulation amount according to the set exposure time. .
An image pickup apparatus according to a ninth aspect of the invention generates an electric charge according to the amount of incident light, an image pickup element having a photoelectric conversion unit for accumulating the generated electric charge, and a case where the accumulated electric charge exceeds a predetermined accumulation amount In addition, the discharge unit for discharging the accumulated electric charge, the first setting unit for setting the exposure time of the image sensor, the second setting unit for setting the imaging sensitivity of the image sensor, and the predetermined accumulation amount are set to the first setting. Switching means for switching based on the exposure time set by the means and the imaging sensitivity set by the second setting means.

  According to the present invention, it is possible to prevent white spots from occurring in an image.

1 is a cross-sectional view illustrating the configuration of a camera according to an embodiment of the present invention. Block diagram illustrating functional configuration of control circuit The figure which shows typically discharge | emission of the electric charge of the image pick-up element by 1st Embodiment The figure which shows the relationship of the charge accumulation amount set according to exposure time and imaging sensitivity The figure which shows typically discharge | emission of the electric charge of the image pick-up element by 2nd Embodiment

-First embodiment-
A camera according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a main configuration of the digital camera 1. The digital camera 1 includes a camera body 100 and an interchangeable lens 200, and the interchangeable lens 200 is attached to the camera body 100 via a mount unit (not shown).

  The interchangeable lens 200 is provided with a photographing lens 201, a diaphragm 202, and the like. The photographing lens 201 is composed of a plurality of optical lens groups such as a zooming lens and a focusing lens, and forms an image of a light flux from a subject near the focal plane. In FIG. 1, the taking lens 201 is shown as a representative lens for convenience of explanation. The diaphragm 202 forms an aperture having a variable aperture diameter at the center of the optical axis of the photographing lens 201 for light amount adjustment.

  The camera body 100 is provided with an image sensor 101, a control circuit 102, a liquid crystal display element drive circuit 103, a liquid crystal display element 104, an eyepiece 105, an operation unit 106, a memory card 107, and the like. In the image sensor 101, photoelectric conversion elements (pixels) made of, for example, a CCD or a CMOS are two-dimensionally arranged. The image sensor 101 is driven in accordance with the control of the control circuit 102 to be described later, captures a subject image formed by a light beam that has passed through the interchangeable lens 200, and outputs a pixel signal obtained by the imaging.

  The image pickup device 101 is configured to change the image pickup sensitivity (exposure sensitivity) in a predetermined step within a range equivalent to ISO 100 to ISO 1600, for example, that is, change the operation state of the signal output of the pixel signal from the image pickup device 101. ing. The imaging sensitivity refers to a controlled amount that changes the detection sensitivity of charges accumulated in the image sensor 101 or the amplification gain of an amplifier circuit (not shown). An operation (gain changing operation) for changing the imaging sensitivity of the imaging device 101 is performed by the user using an operation unit 106 described later. Details of the image sensor 101 will be described later.

  The control circuit 102 includes a CPU, ROM, RAM, and the like (not shown), and is an arithmetic circuit that controls each component of the digital camera 1 and executes various data processing. As shown in FIG. 2, the control circuit 102 functionally includes an imaging control unit 102a and an image processing unit 102b. The imaging control unit 102a controls the drive control of the image sensor 101 and the reading of pixel signals from the image sensor 101, that is, the charge accumulation amount of the image sensor 101. The image processing unit 102b performs image processing such as white balance processing, gamma correction processing, color interpolation processing, edge enhancement, and vignette correction on the pixel signal output from the image sensor 101 to generate image data. The control circuit 102 performs focus detection calculation and focus adjustment of the interchangeable lens 200 based on the pixel signal output from the image sensor 101, calculates the luminance value of the subject using the pixel signal, and sets an appropriate value. The shutter time (exposure time) and the aperture value are calculated so that the exposure amount can be obtained. Details of the imaging control unit 102a will be described later.

  The liquid crystal display element driving circuit 103 shown in FIG. 1 functions as an electrical viewfinder. The liquid crystal display element driving circuit 103 causes the liquid crystal display element 104 to display a through image corresponding to the image data generated by the control circuit 102 using the pixel signal read from the imaging element 101. As a result, the user can observe the through image through the eyepiece 105. The memory card 107 is a non-volatile recording medium that records image data generated by the control circuit 102.

  The operation unit 106 is a switch that receives a user operation. The operation unit 106 includes a power switch, a release switch, a display changeover switch for other setting menus, a setting menu determination button, a sensitivity setting switch for a gain changing operation for changing the above-described imaging sensitivity, and the like.

  The image sensor 101 according to the first embodiment will be described with reference to FIG. FIG. 3 schematically shows the structure of the image sensor 101 for convenience of explanation. The image sensor 101 has a pixel having a plurality of photoelectric conversion units, and is configured to be able to control the charge accumulation amount by discharging excess charge accumulated in each pixel by a known vertical overflow drain method. FIG. 3 is a diagram schematically showing a cross-sectional structure of some of the plurality of pixels constituting the image sensor 101. As shown in FIG. 3, the pixel 150 includes a photoelectric conversion unit 151 and a first discharge unit 152 formed on the substrate. The photoelectric conversion unit 151 is a photodiode that generates a charge according to the amount of incident light of the light beam incident through the interchangeable lens 200 and accumulates the generated charge.

  The first discharge unit 152 discharges the charge accumulated in the photoelectric conversion unit 151 in excess of a predetermined accumulation amount onto the substrate. That is, as shown in FIG. 3A, when the accumulated charge exceeds a predetermined accumulation amount Th, the charge is discharged. In the present embodiment, the first discharge unit 152 is configured to be switchable between the first accumulation amount and the second accumulation amount according to the control of the imaging control unit 102a. FIG. 3B shows a case where the first accumulation amount Th1 is set, and FIG. 3C shows a case where the second accumulation amount Th2 is set. As shown in FIGS. 3B and 3C, the second accumulation amount Th2 is set to be larger than the first accumulation amount Th1. That is, when the second accumulation amount Th2 is set, the amount of charge accumulated in the photoelectric conversion unit 151 is larger than when the first accumulation amount Th1 is set.

  The first accumulation amount Th1 and the second accumulation amount Th2 described above are determined in advance based on the exposure time of the photoelectric conversion unit 151, that is, the shutter time and the imaging sensitivity, using results of tests and experiments. The The first accumulation amount Th1 is, for example, when the imaging sensitivity is set to the lowest sensitivity that can be taken by the digital camera 1 (ISO 100 in the present embodiment) and the shutter time is set to a long time (for example, 1 second or more). This value is determined as a value at which the charge accumulated in the photoelectric conversion unit 151 does not leak to the adjacent pixel 150. The second accumulation amount Th2 is such that the charge accumulated in the photoelectric conversion unit 151 leaks to the adjacent pixel 150 when the imaging sensitivity is set to ISO 100 and the shutter time is set to a short time (for example, less than 1 second). It is determined as a value not to be issued.

Hereinafter, switching processing of a predetermined accumulation amount by the imaging control unit 102a will be described. In the following description, the following three cases (1) to (3) are performed.
(1) The imaging sensitivity is set to the lowest sensitivity, and the shutter speed is long (the shutter speed is low).
(2) When the imaging sensitivity is set to the lowest sensitivity and the shutter speed is short (the shutter speed is high).
(3) When an imaging sensitivity other than the lowest sensitivity is set.

(1) When the imaging sensitivity is set to the lowest sensitivity and the shutter time is a long time The imaging control unit 102a determines whether the user has operated the operation unit 106 to set the imaging sensitivity to ISO 100, which is the lowest sensitivity. Determine whether. That is, the imaging control unit 102a determines whether or not an operation signal indicating that the user has performed an operation of setting the imaging sensitivity to ISO 100 is output from the operation unit 106. When an operation signal is output from the operation unit 106, the imaging control unit 106 sets the imaging sensitivity of the image sensor 101 to ISO 100. Then, when the shutter time calculated by the control circuit 102 is a long time of 1 second or longer, that is, when the exposure time is long, the image pickup control unit 102a stores the charge accumulation amount with respect to the image pickup device 101 as the first accumulation. A first instruction signal instructing to set the amount Th1 is output.

  When the first instruction signal is input from the imaging control unit 102a, the imaging element 101 sets the charge accumulation amount of the photoelectric conversion unit 151 to the first accumulation amount Th1. As a result, the first discharge unit 152 included in all the pixels 150 constituting the image sensor 101 is set as shown in FIG. Therefore, when the exposure time is long, the accumulated amount of charge in the photoelectric conversion unit 151 increases due to dark current. Therefore, by setting the first accumulated amount Th1 and increasing the discharged amount of accumulated charge, adjacent pixels The occurrence of blooming phenomenon in which electric charge leaks to 150 is suppressed.

(2) When the imaging sensitivity is set to the lowest sensitivity and the shutter speed is short, the imaging control unit 102a receives an operation signal indicating that the user has performed an operation to set the imaging sensitivity to ISO 100. If it is determined that the image is output from 106, the imaging control unit 30 sets the imaging sensitivity of the imaging element 101 to ISO100. Then, the imaging control unit 102a performs the second accumulation of the charge accumulation amount with respect to the imaging element 101 when the shutter time calculated by the control circuit 102 is shorter than 1 second, that is, when the exposure time is short. A second instruction signal instructing to set the amount Th2 is output.

  When receiving the second instruction signal from the imaging control unit 102a, the imaging element 101 sets the charge accumulation amount of the photoelectric conversion unit 151 to the second accumulation amount Th2. As a result, the first discharge unit 152 included in all the pixels 150 constituting the image sensor 101 is set as shown in FIG. Therefore, when the exposure time is short, the amount of dark current generated is small, and therefore, the amount of charge accumulated in the photoelectric conversion unit 151 is smaller than when the exposure time is long. Therefore, the second accumulation amount Th2 is set and blooming is performed. The dynamic range is secured while suppressing the occurrence of the phenomenon.

(3) When Imaging Sensitivity is Set to Other Than Minimum Sensitivity The imaging control unit 102a determines whether or not an operation signal indicating that an operation for setting the imaging sensitivity to other than ISO 100 is performed by the user from the operation unit 106. Determine. When an operation signal is output from the operation unit 106, the imaging control unit 102a sets the imaging sensitivity of the image sensor 101 to an imaging sensitivity corresponding to the user's setting operation. Then, the imaging control unit 102a outputs a first instruction signal for instructing the imaging element 101 to set the charge accumulation amount to the first accumulation amount Th1. That is, the imaging control unit 102a sets the charge accumulation amount of the photoelectric conversion unit 151 to the first accumulation amount Th1 regardless of the length of the exposure time. As a result, the first discharge unit 152 included in all the pixels 150 constituting the image sensor 101 is set as shown in FIG. In cases other than the minimum imaging sensitivity, the charge accumulated in the photoelectric conversion unit 151 is amplified in the subsequent processing. Therefore, by setting the first accumulation amount Th1, the accumulated amount of charge in the photoelectric conversion unit 151 is reduced. The dynamic range is secured while suppressing the blooming phenomenon.

According to the digital camera 1 according to the first embodiment described above, the following operational effects can be obtained.
The image sensor 101 includes a photoelectric conversion unit 151 that generates charges according to the amount of incident light and accumulates the generated charges. The first discharge unit 152 discharges the charge accumulated in the photoelectric conversion unit 151 when the accumulated charge exceeds a predetermined accumulation amount. The control circuit 102 sets the exposure time of the image sensor 101 and sets the imaging sensitivity of the image sensor 101 according to the operation of the operation unit 106. The imaging control unit 102a switches the charge accumulation amount of the photoelectric conversion unit 151 based on the exposure time and imaging sensitivity. That is, when the imaging sensitivity is set to the lowest sensitivity and the exposure time is set to a long time, or when the imaging sensitivity is set to other than the lowest sensitivity, the imaging control unit 102a The charge accumulation amount is set to the first accumulation amount Th1. Furthermore, when the imaging sensitivity is set to the lowest sensitivity and the exposure time is set to a short time, the imaging control unit 102a sets the second charge accumulation amount of the photoelectric conversion unit 151 larger than the first accumulation amount Th1. Is set to the accumulation amount Th2. Therefore, even if the exposure time is long, the charge accumulation amount of the photoelectric conversion unit 151 is set low, so that the blooming phenomenon that the accumulated charge leaks to the adjacent pixels is suppressed, and a huge white spot appears in the image. It is possible to suppress degradation of image quality due to the operation. In addition, when the exposure time is short, the charge accumulation amount of the photoelectric conversion unit 151 is set high, so that the blooming phenomenon can be suppressed and the dynamic range of the photoelectric conversion unit 151 can be secured.

-Second Embodiment-
A digital camera 1 according to a second embodiment of the present invention will be described with reference to FIG. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and different points will be mainly described. Points that are not particularly described are the same as those in the first embodiment. This embodiment is different from the first embodiment using the vertical overdrain method in that a method of intermittently discharging the charge accumulated excessively in the photoelectric conversion unit to the FD unit is used.

  The image sensor 101 according to the second embodiment will be described with reference to FIG. FIG. 5 schematically shows the structure of the image sensor 101 for convenience of explanation. The image pickup device 101 has a plurality of photoelectric conversion units (pixels) configured by, for example, CMOS, and intermittently discharges to a FD that accumulates charges while discharging a part of the charges generated by photoelectric conversion. Thus, the charge accumulation amount can be controlled. FIG. 5 is a diagram schematically illustrating a cross-sectional structure of a part of a plurality of pixels constituting the image sensor 101. As shown in FIG. 5, the pixel 150 includes a photoelectric conversion unit 151 and a second discharge unit 153 formed on the substrate.

  The second discharging unit 153 discharges a part of the accumulated charges to the FD unit while accumulating the charges by the photoelectric conversion unit 151, so that the excessive charge exceeds a predetermined accumulation amount. Prevents accumulation. That is, as shown in FIG. 5A, the electric charge accumulated at a predetermined discharge amount per unit time is discharged. In the present embodiment, the second discharge unit 153 is configured to be switchable between the first discharge amount and the second discharge amount in accordance with the control of the imaging control unit 102a. FIG. 5B shows a case where the first discharge amount Ex1 is set, and FIG. 5C shows a case where the second accumulation amount Ex2 is set. In this case, the first discharge amount Ex1 is set so that the discharge amount per unit time is larger than the second discharge amount Ex2. That is, when the second discharge amount Ex2 is set, the amount of charge accumulated in the photoelectric conversion unit 151 is larger than when the first discharge amount Ex1 is set. In FIGS. 5B and 5C, the first discharge amount Ex1 is larger than the second discharge amount Ex2 by drawing with the thickness of the second discharge portion 153 changed. This is shown schematically.

  The first discharge amount Ex1 and the second discharge amount Ex2 described above are determined in advance based on the exposure time of the photoelectric conversion unit 151, that is, the shutter time and the imaging sensitivity, using results of tests and experiments. The The first discharge amount Ex1 is accumulated in the photoelectric conversion unit 151 when, for example, the imaging sensitivity is set to the lowest sensitivity (ISO 100) that the digital camera 1 can take and the shutter time is set to a long time (1 second or more). The determined charge is determined as a value that does not leak into the adjacent pixel 150. In other words, the first discharge amount Ex1 is determined so that the charge accumulation amount of the photoelectric conversion unit 151 does not exceed the first accumulation amount Th1. As for the second discharge amount Ex2, when the imaging sensitivity is set to ISO 100 and the shutter time is set to a short time (less than 1 second), the charge accumulated in the photoelectric conversion unit 151 leaks to the adjacent pixel 150. Determined as no value. In other words, the second discharge amount Ex2 is determined so that the charge accumulation amount of the photoelectric conversion unit 151 does not exceed the second accumulation amount Th2.

  When the imaging sensitivity is set to the lowest sensitivity and the shutter speed is set to the long time, the imaging control unit 102a sets the charge discharge amount to the first discharge amount Ex1 with respect to the image sensor 101. A third instruction signal for instructing is output. When receiving the third instruction signal from the imaging control unit 102a, the imaging element 101 sets the discharge amount of the second discharge unit 153 to the first discharge amount Ex1. As a result, the second discharge unit 153 included in all the pixels 150 constituting the image sensor 101 is set as shown in FIG.

  When the imaging sensitivity is set to the lowest sensitivity and the shutter time is set to the short time, the imaging control unit 102a sets the charge discharge amount to the second discharge amount Ex2 with respect to the image sensor 101. A fourth instruction signal for instructing is output. When receiving the fourth instruction signal from the imaging control unit 102a, the image sensor 101 sets the discharge amount of the second discharge unit 153 to the second discharge amount Ex2. As a result, the second discharge unit 153 included in all the pixels 150 constituting the image sensor 101 is set as shown in FIG.

  The imaging control unit 102a instructs the imaging device 101 to set the charge discharge amount to the first discharge amount Ex11 when an operation for setting the image pickup sensitivity other than the ISO 100 having the lowest sensitivity is performed. An instruction signal is output. That is, the imaging control unit 102a sets the charge accumulation amount of the second discharge unit 153 to the first discharge amount Ex1 regardless of the length of the exposure time. As a result, the second discharge unit 153 included in all the pixels 150 constituting the image sensor 101 is set as shown in FIG.

  Also in the digital camera 1 according to the second embodiment described above, the same operational effects as those obtained by the digital camera 1 according to the first embodiment can be obtained. That is, even when the exposure time is a long time, the blooming phenomenon can be suppressed, and deterioration of image quality due to the appearance of a huge white spot in the image can be suppressed. Further, when the exposure time is short, the blooming phenomenon can be suppressed and the dynamic range of the photoelectric conversion unit 151 can be secured.

The digital camera 1 according to the first and second embodiments described above can be modified as follows.
(1) The imaging control unit 102a may switch between the first accumulation amount Th1 and the second accumulation amount Th2 only according to the exposure time. That is, regardless of the imaging sensitivity, the imaging control unit 102a sets the first accumulation amount Th1 when the shutter time is long and the second accumulation amount Th2 when the shutter time is short. Should be set.

(2) The first accumulation amount Th1 and the second accumulation amount Th2 may be switched according to the temperature of the image sensor 101. In this case, when the temperature of the image sensor 101 detected by a temperature sensor (not shown) is higher than a predetermined temperature, the imaging control unit 102a sets the first accumulation amount Th1 and the temperature is lower than the predetermined temperature. May be set to the second accumulation amount Th2. As a result, when the temperature of the image sensor 101 is high, the charge accumulation amount of the photoelectric conversion unit 151 can be reduced to suppress the blooming phenomenon.

(3) The imaging control unit 102a switches between a plurality of accumulation amounts instead of switching the charge accumulation amount of the photoelectric conversion unit 151 between the first accumulation amount Th1 and the second accumulation amount Th2. May be performed. For example, when the exposure time is calculated to be medium seconds, the imaging control unit 102a sets the third accumulation amount that is larger than the first accumulation amount Th1 and smaller than the second accumulation amount Th2. May be.

  In addition, the present invention is not limited to the above-described embodiment as long as the characteristics of the present invention are not impaired, and other forms conceivable within the scope of the technical idea of the present invention are also within the scope of the present invention. included. The embodiments and modifications used in the description may be configured by appropriately combining them.

101 imaging device, 102 control circuit, 102a imaging control unit,
106 operation unit, 150 pixels, 151 photoelectric conversion unit,
152 1st discharge part, 153 2nd discharge part

Claims (9)

An image sensor having a photoelectric conversion unit that generates charges according to the amount of incident light and accumulates the generated charges;
Discharging means for discharging the accumulated charge when the accumulated charge exceeds a predetermined accumulation amount;
First setting means for setting an exposure time of the image sensor;
Switching means for switching the predetermined accumulation amount according to the exposure time set by the first setting means,
The switching means sets the predetermined accumulation amount to the first accumulation amount when the exposure time is set to the first exposure time, and the exposure time is a second shorter than the first exposure time. When the exposure time is set, the imaging apparatus is characterized in that the predetermined accumulation amount is set to a second accumulation amount that is larger than the first accumulation amount. An image sensor having a photoelectric conversion unit that generates charges according to the amount of incident light and accumulates the generated charges;
Discharging means for discharging the accumulated charge when the accumulated charge exceeds a predetermined accumulation amount;
First setting means for setting an exposure time of the image sensor;
Second setting means for setting the imaging sensitivity of the imaging device;
Switching means for switching the predetermined accumulation amount based on the exposure time set by the first setting means and the imaging sensitivity set by the second setting means,
When the imaging sensitivity is set to the lowest sensitivity and the exposure time is set to a long second, or when the imaging sensitivity is set to other than the lowest sensitivity, the switching unit is configured to store the predetermined accumulation. When the amount is set to the first accumulation amount, the imaging sensitivity is set to the minimum sensitivity, and the exposure time is set to a short second, the predetermined accumulation amount is set to be larger than the first accumulation amount. 2. An imaging apparatus characterized in that the accumulation amount is set. The imaging device according to claim 1,
A second setting means for setting an imaging sensitivity of the image sensor;
The switching unit switches the predetermined accumulation amount between the first accumulation amount and the second accumulation amount based on the exposure time and the imaging sensitivity set by the second setting unit. An imaging device. The imaging device according to claim 3.
The switching means sets the predetermined accumulation amount to the first accumulation amount when the imaging sensitivity is set to the lowest sensitivity and the exposure time is set to the first exposure time, The imaging apparatus, wherein when the imaging sensitivity is set to the lowest sensitivity and the exposure time is set to the second exposure time, the predetermined accumulation amount is set to the previous second accumulation amount. The imaging apparatus according to claim 4,
The switching device sets the first accumulation amount regardless of the exposure time when the imaging sensitivity is set to a value other than the minimum sensitivity. In the imaging device according to any one of claims 1 to 5,
The discharging means discharges a part of the charge accumulated while accumulating the charge by the imaging device, and when the second accumulation amount is set rather than the first accumulation amount. The image pickup apparatus is characterized in that the discharge amount of charge per unit time is reduced. In the imaging device according to any one of claims 1 to 5,
The switching means sets a threshold corresponding to each of the first accumulation amount and the second accumulation amount,
The image pickup apparatus, wherein the discharge means discharges the charge when the charge accumulated in the image pickup device exceeds the threshold set by the switching means. An image sensor having a photoelectric conversion unit that generates charges according to the amount of incident light and accumulates the generated charges;
Discharging means for discharging the accumulated charge when the accumulated charge exceeds a predetermined accumulation amount;
Setting means for setting an exposure time of the image sensor;
An image pickup apparatus comprising: switching means for switching the predetermined accumulation amount according to the set exposure time. An image sensor having a photoelectric conversion unit that generates charges according to the amount of incident light and accumulates the generated charges;
Discharging means for discharging the accumulated charge when the accumulated charge exceeds a predetermined accumulation amount;
First setting means for setting an exposure time of the image sensor;
Second setting means for setting the imaging sensitivity of the imaging device;
An imaging apparatus comprising: switching means for switching the predetermined accumulation amount based on an exposure time set by the first setting means and an imaging sensitivity set by the second setting means.

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