JP2015056709A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform measures for reduction in surrounding light amount without deterioration of image quality due to electrical image data amplification.SOLUTION: An imaging apparatus detects photographing instructions by a photographer (S201), thereby obtaining zoom position information on a lens barrel portion (S202). The imaging apparatus performs AF processing (S203), and performs AE processing for determining an exposure condition to each pixel for optimum luminance in an imaging region in consideration of reduction in light amount around the lens barrel portion (S204, S205, S206). In the AE processing, exposure time is determined for each pixel so as to longer expose to the pixel at a position around an imaging device than the pixel at a center position thereof. Next, under the exposure condition determined by the AE processing, photographing is performed while controlling the exposure time for each pixel (S207), and the photographed image data is recorded (S208).

Description

  The present invention relates to a method for controlling an image pickup apparatus having an image pickup element that can control exposure for each region, and a method for correcting an image.

  In an imaging device that captures a subject by obtaining an optical image through a lens, a so-called peripheral light amount drop phenomenon occurs in the captured subject image in which the amount of light decreases from the center of the image to the periphery of the image. Occur.

  Further, it is known that the peripheral light amount drop phenomenon is determined by the relationship between the characteristics of the lens provided in the imaging apparatus and the characteristics of the solid-state imaging device. Specifically, the peripheral light amount drop amount is uniquely determined by the relationship with the position of the solid-state imaging device with respect to the effective image circle (the region where the light hits uniformly). However, in this case, it is a premise that the effective pixel center of the solid-state imaging device and the optical axis center of the lens are coincident. The amount of decrease in the amount of peripheral light also depends on the aperture value of the lens, and the amount of decrease in the amount of light is significant on the open side and the small aperture side. On the open side, as a general lens characteristic, the incident light at the center of the lens is incident as a circular light beam, but the incident light at the corner of the lens always passes through the corner, so the light is scattered, Incident light becomes an elliptical light beam, and the amount of light decreases.

  For this reason, when the aperture is in the open state, more incident light passes through the corners of the lens, so that the phenomenon of light scattering becomes more prominent. On the small aperture side, the amount of peripheral light decreases due to the occurrence of optical diffraction. For this reason, when the aperture value is wide or small, it is greatly affected by the peripheral light amount drop phenomenon.

  In order to avoid this phenomenon, it is possible to use a lens in which the effective image circle of the lens included in the imaging device is sufficiently larger than the number of pixels included in the solid-state imaging device. However, when a lens satisfying such conditions is used, the size of the lens itself becomes large, and it is difficult to reduce the size of the imaging device. In addition, as the downsizing of the image pickup device is required and it is difficult to provide a large lens, the number of pixels of the solid-state image pickup device provided in the image pickup device is rapidly increasing, and the peripheral light amount drop phenomenon is remarkable. It has become to.

  As described above, when an imaging apparatus having a lens that is not sufficiently large is used to photograph a subject with a low contrast, a decrease in the amount of peripheral light becomes remarkable, which is a cause of a decrease in image quality. In view of this, there has been proposed a technique for correcting a peripheral light amount drop by compensating and flattening a light amount reduction characteristic from the center to the periphery of an image according to an aperture value (see Patent Document 1).

  FIG. 9 shows the relationship among the screen position, peripheral light amount, and correction amount in Patent Document 1. As shown in FIG. 9, in Patent Document 1, by performing peripheral light amount drop correction, a gain that is equivalent to the brightness of the central portion is obtained by electrically amplifying the decrease in illuminance at the peripheral portion of the screen. The correction was applied.

JP-A-61-105974

  In the technique disclosed in Patent Document 1, the signal at the screen peripheral portion is compared with the signal at the screen central portion when the illuminance at the screen peripheral portion is optically decreased with respect to the illuminance at the screen central portion. It is greatly amplified electrically. Therefore, there is a problem in that the signal amount to noise ratio (hereinafter referred to as the S / N ratio) in the screen peripheral portion is lower than the S / N ratio in the central portion of the screen, that is, the image quality deteriorates.

The imaging apparatus according to the present invention, the subject light incident through the imaging lens,
It has at least two or more areas composed of one or more pixels, starts exposure independently from each other in units of the areas, and reads image information acquired by exposure all at once, or in all areas The exposure is started in a batch, and the image information acquired by exposure is read out independently from each other in the region unit, or the exposure is started independently from each other in the region unit, and the image information acquired by the exposure is read out in the region unit. Imaging means for reading out independently of each other;
Imaging control means for controlling the imaging means to start exposure and read out image information;
Photometric means for determining exposure conditions in at least one or more of the regions located near the center of the light receiving surface of the imaging means;
Lens state detection means for acquiring information on the zoom position and aperture state of the imaging lens;
An exposure time determination means for determining an exposure time for each region based on information by the lens state detection means and an exposure condition by the photometry means;
The imaging control means controls the imaging means so as to perform exposure with the exposure time of the area unit determined by the exposure time determination means, and shoots.

  As described above, according to the present invention, in consideration of a decrease in the amount of peripheral light, the peripheral pixel of the image sensor is controlled to be exposed to a longer exposure with respect to the central pixel. It is possible to acquire image data in which the peripheral light amount drop is corrected while suppressing deterioration in image quality due to electrical amplification.

It is a block diagram which shows the structure of the imaging device which concerns on the 1st and 2nd embodiment of this invention. 3 is a flowchart of a shooting operation of the imaging apparatus according to the first embodiment of the present invention. It is a figure explaining determination of exposure of the imaging device concerning the 1st and 2nd embodiment of the present invention. It is a figure explaining the determination of the exposure time of the imaging device which concerns on the 1st and 2nd embodiment of this invention. 6 is a timing chart for explaining the exposure timing of the imaging apparatus according to the first embodiment of the present invention. It is a flowchart of imaging | photography operation | movement of the imaging device which concerns on the 2nd Embodiment of this invention. It is a figure explaining gain correction of an imaging device concerning a 2nd embodiment of the present invention. It is a timing chart explaining the timing of exposure of the imaging device concerning a 2nd embodiment of the present invention. It is a conceptual diagram of the peripheral light amount fall correction | amendment which concerns on the prior art example of this invention.

<First Embodiment>
Hereinafter, exemplary and preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram illustrating a schematic configuration example of an imaging apparatus according to the first embodiment of the present invention.

  In FIG. 1, reference numeral 101 denotes a lens barrel that includes a zoom lens, a focus lens, a diaphragm, a shutter, and a mechanism (actuator or the like) that drives them. An imaging unit 102 includes an image sensor such as a CCD sensor or a CMOS sensor that converts an optical image into an electrical signal, and an A / D converter that converts image data from the image sensor into digital data. In the present invention, the image pickup device of the image pickup unit 102 can perform exposure control and charge readout control for all the pixels at once, and can also perform exposure control and charge readout control for each pixel. Reference numeral 103 denotes an imaging control unit that performs exposure control and charge readout control for all the pixels of the imaging device of the imaging unit 102 or for each pixel.

  A timing generation unit 104 supplies a clock signal and a control signal to the imaging unit 102 and the imaging control unit 103, and is controlled by the system control unit 110.

  An image processing unit 105 performs resize processing such as predetermined pixel interpolation and reduction and color conversion processing on the image data from the imaging unit 102. Further, the image processing unit 105 performs predetermined calculation processing using the generated image data, and the system control unit 110 performs distance measurement control based on the obtained calculation result, whereby a TTL (Through the Lens) method. AF (Autofocus) processing is performed. The image processing unit 105 further performs predetermined calculation processing using the generated image data, and also performs TTL AWB (Automatic White Balance) processing based on the obtained calculation result.

  Reference numeral 106 denotes a memory for storing captured still images and moving images. Image data from the imaging unit 102 is written into the memory 106 via the image processing unit 105. The memory 106 has a storage capacity sufficient to store a predetermined number of still images, a moving image and sound for a predetermined time. Thereby, even in the case of continuous shooting in which a plurality of still images are continuously shot, a large amount of image writing can be performed on the memory 106 at high speed. The memory 106 can also be used as a work area for the system control unit 110. The memory 106 is also used as a write buffer for the recording medium 109. Further, the memory 106 also serves as an image display memory, and the display image data written in the memory 106 is displayed on a display unit 107 including an LCD or the like. If the captured image data is sequentially displayed using the display unit 107, an electronic finder function (through display) can be realized.

  A recording control unit 108 reads out image data written in the memory 106 and records the image data in a recording medium 109 such as a memory card or a hard disk.

  Reference numeral 110 denotes a system control unit that controls the entire imaging apparatus 100. The system control unit 110 includes, for example, a microprocessor, a program ROM, and a RAM, and controls the overall operation of the imaging apparatus 100 by loading a control program stored in advance in the program ROM into the RAM and executing it. The control program referred to here is a program for executing various flowcharts described later in the present embodiment.

  A lens barrel control unit 111 controls a mechanism (actuator or the like) that drives each lens included in the lens barrel unit 101 in accordance with control from the system control unit 110. Reference numeral 112 denotes a lens barrel state detection unit that detects information on the position and aperture state of the zoom lens included in the lens barrel unit 101.

  Reference numeral 113 denotes an operation unit. The operation unit 113 is an input device group for a user to perform various instructions and settings on the image capturing apparatus 100 such as a switch, a button, and a dial. The operation unit 113 includes a power switch, a mode switch, a shutter button, a menu button, a direction button, An execution button is typically included.

  Reference numeral 114 denotes a power supply control unit including a DC-DC converter, a switch circuit for switching an energization block, and the like. The power control unit 114 controls the DC-DC converter based on the control of the system control unit 110 and supplies a necessary voltage to each block for a necessary period.

  Reference numeral 115 denotes a power supply unit including a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a NiCd battery, a NiMH battery, or a Li battery, or an AC adapter.

  The operation processing of the imaging apparatus 100 having the above configuration will be described with reference to the flowchart shown in FIG.

  When the photographer inputs a photographing instruction by fully pressing a shutter button included in the operation unit 115, the system control unit 110 detects this (S201).

  Next, the system control unit 110 acquires the zoom position information of the lens barrel unit 101 from the lens barrel state detection unit 112 and records it in the built-in RAM (S202).

  Subsequently, AF (Autofocus) processing is performed so as to optimize the focus (S203). The AF processing is not directly related to the present invention, and a known method can be applied, and thus detailed description thereof is omitted.

  Next, in steps S204 to S206, an AE (Auto Exposure) process is performed in which an exposure condition is determined for each pixel so that the luminance of the imaging region is optimized in consideration of a decrease in the amount of light around the lens barrel 101. It demonstrates in order according to a flow.

  First, based on the control of the system control unit 110, the imaging control unit 103 controls the imaging unit 102 to perform photometry processing, and obtains the subject brightness Bv_a in the photometric region of the imaging element of the imaging unit 102 (S204). In the present embodiment, the photometric area is a central area of the image sensor of the image capturing unit 102 that is less affected by a decrease in peripheral light amount. Next, the exposure conditions of the photographing sensitivity Sv_a, the exposure time Tv_a, and the aperture value Av_a in the photometric area are determined according to the following formula (formula 1) so that an appropriate exposure value Ev can be obtained from the acquired subject luminance value Bv_a. .

Ev = Bv_a + Sv_a = Tv_a + Av_a (Formula 1)
The subject luminance value Bv_a, the photographing sensitivity Sv_a, the exposure time Tv_a, and the aperture value Av_a in the photometric area are values expressed in APEX.

  In the present embodiment, the built-in ROM of the system control unit 110 stores a program diagram as shown in FIG. The system control unit 110 determines the exposure conditions of the photographing sensitivity Sv_a, the exposure time Tv_a, and the aperture value Av_a at which appropriate exposure is obtained in the strobe flash photography according to the program diagram from the acquired subject luminance value Bv_a of the photometric area (S205). ). For example, when the exposure value Ev is Ev10 as in the example shown in FIG. 3, the exposure time Tv_a is determined as Tv7 and the aperture value Av_a is determined as Av3 from the position A in the figure.

  It is good to describe the model in a simplified form, but please explain how it should be as it is easy. The drop in ambient light appears in a circle, so ideally you can change the shutter speed along the circle.

  Next, the system control unit 110 determines an exposure condition for each pixel of the image sensor of the imaging unit 102 (S206). In the present embodiment, among the exposure conditions of each pixel, the shooting sensitivity Sv of each pixel is the same as the shooting sensitivity Sv_a determined in the photometric area. Similarly, the aperture value Av of each pixel is the same as the aperture value Av_a determined in the photometric area. A method for determining the exposure time Tv of each pixel will be described with reference to FIG. The built-in ROM of the system control unit 110 stores the exposure time of each pixel according to the zoom position information of the lens barrel unit 101 acquired in step S202 as shown in FIG. 4A and the aperture value Av_a determined in step S205. A table indicating Tv is stored. In FIG. 4A, 401 represents zoom position information. The state where the zoom position is at the widest angle side is indicated as “W”, the state at the maximum telephoto side is indicated as “T”, and intermediate positions thereof are indicated as “M1”, “M2”,. Reference numeral 402 denotes the aperture value Av_a of the photometric area.

  In the present embodiment, FIG. 4A shows Av_a = 1 to Av_a = 6, but the table is not necessarily limited to this range. A table 403 indicates the exposure time of each pixel stored for each zoom position information and aperture value Av_a. In the peripheral light amount drop, the light amount falls concentrically from the center position of the image sensor toward the peripheral position. Therefore, the exposure time of each pixel of the table 503 corresponds to the change in the light amount of the peripheral light amount drop. The exposure time for each pixel increases concentrically from the pixel toward the peripheral pixel. As an example of the table 403, FIG. 4B shows the pixel size of the image sensor as horizontal 8 pixels and vertical 6 pixels. Reference numeral 404 denotes a pixel exposure time [s].

  For example, the exposure time of the pixel at the (1,2) coordinate in the image sensor of the imaging unit 102 is indicated by T (1,2). As for the exposure time 404 of each pixel, each pixel is properly exposed in consideration of a decrease in peripheral light amount due to the lens barrel 101 based on a value Ttv_a [s] obtained by converting the exposure time Tv_a (APEX notation) of the photometric area. To be determined. That is, it is determined that the pixels in the peripheral part of the image sensor are exposed to the central pixel for a longer time. For example, in FIG. 4B, the exposure time T (1,2) of the pixel at the (1,2) coordinate, which is the peripheral pixel of the image sensor, is the exposure time Ttv_a [s of the pixel in the central area A. The exposure time is determined to be 1.8 times that of the above. Reference numerals 405, 406, and 407 denote areas composed of pixels having the same exposure time. The area surrounded by 405 is the area A and the area other than the area A surrounded by 406 is the area surrounded by areas B and 407. A region other than A and B is a region C, and the other region is a region D. Here, in the present embodiment, the photometric area is the area A.

  Next, the imaging control unit 103 performs imaging by controlling the exposure time for each pixel of the imaging element of the imaging unit 102 based on the exposure condition for each pixel set in step S206 (S207).

  The operation of the imaging process in this embodiment will be described with reference to the imaging process timing chart of FIG.

  In FIG. 5, VD represents a vertical synchronization signal, and is supplied from the timing generation unit 104 to the imaging unit 102 and the imaging control unit 103. There is one field from the VD fall to the next VD fall, and one piece of image data is acquired from the imaging unit 102 during this period.

  A quadrangle shown in the VD period schematically shows the exposure timing for each pixel of the image sensor controlled by the imaging control unit 103. Each left side of the quadrangle indicates the timing for starting exposure of the pixel, and each right side indicates the timing for completing the exposure of the pixel and reading the charge of the pixel. The lateral width of the rectangle indicates the pixel exposure time. Reference numerals 501 to 504 denote timings at which exposure of pixels in the areas A to D indicated by 405 to 407 in FIG. In the present embodiment, the imaging control unit 103 starts exposure at different timing for each pixel in each area in accordance with the exposure time for each pixel in each area shown in FIG. The imaging unit 102 is controlled to do so. After the exposure of all the pixels is completed, the imaging control unit 103 performs A / D conversion on the charges of the pixels read after the exposure is completed, and acquires image data.

  Next, the system control unit 110 records the image data acquired in step S <b> 207 in the memory 106. Then, the recording control unit 108 reads out the image data recorded in the memory 106 and executes a recording process of writing the image data as an image file on the recording medium 109 (S208).

  As described above, according to the present embodiment, image data can be obtained by controlling and photographing the peripheral pixels of the image sensor to be longer exposed to the central pixels in consideration of a decrease in peripheral light amount. Thus, it is possible to obtain image data in which the peripheral light amount drop is corrected without deterioration of image quality due to electrical amplification.

<Second Embodiment>
Hereinafter, an imaging apparatus according to the second embodiment of the present invention will be described.

  The configuration of the imaging apparatus according to the second embodiment of the present invention is the same as that of the first embodiment except for the image processing unit 105 of FIG. In the present embodiment, the image processing unit 105 performs a peripheral light amount drop correction process based on the control of the system control unit 110. Regarding the configuration of the imaging apparatus according to the second embodiment, the description of the same configuration as that of the first embodiment is omitted.

  The shooting operation of this embodiment will be described with reference to the flowchart shown in FIG.

  In FIG. 6, the same processes as those shown in the flowchart of FIG. 2 of the first embodiment are denoted by the same reference numerals as in FIG. The description of the same processing as in the first embodiment is omitted.

  Hereinafter, a different part from 1st Embodiment is demonstrated.

  In the present invention, at the time of moving image recording, in order to satisfy the frame rate, any pixel of the image sensor of the imaging unit 102 is exposed beyond one field period (hereinafter referred to as VD period) determined by the vertical synchronization signal VD. Can not. Therefore, after step S206 in FIG. 6, the system control unit 110 determines whether or not the exposure time of each pixel is within the VD period (S601). When the exposure time of each pixel is within the VD period (Yes in S601), the AE process is terminated as in the first embodiment. If any one of the exposure times of the pixels exceeds the VD period (No in S601), the exposure time of the pixels exceeding the VD period is set to the maximum exposure time Ttvm [s] that can be exposed within the VD period. Change (S602).

  A pixel whose exposure time has been changed to Ttvm [s] cannot be exposed with an exposure time necessary for correcting the peripheral light amount drop, and the data acquired from the pixel remains affected by the peripheral light amount drop. A gain is applied to the data acquired from the pixel so as to correct the drop. Therefore, after the data acquired from the pixel whose exposure time has been changed to Ttvm [s] is recorded in the built-in ROM by creating a gain correction table for correcting the peripheral light amount drop by the image processing unit 105. The AE process is terminated (S603). The gain correction value G for correcting the data of the pixel whose exposure time is changed to Ttvm [s] in the gain correction table created in step S603 is determined according to the following equation (Equation 2).

G (x, y) = T (x, y) / Ttvm (Formula 2)
Further, the gain correction value G is determined so that the gain correction is not performed on the pixel data whose exposure time is not changed to Ttvm [s].

  For example, in FIG. 4B, the amount of subject light is low, and the exposure time Ttv_a [s] of the photometry area (area A) matches the maximum exposure time Ttvm [s] that can be exposed within the VD period. In this case, the exposure times of the regions B, C, and D all exceed the VD period. In this case, the exposure times of the region B, the region C, and the region D are changed to Ttvm [s], and for example, a gain correction table as shown in FIG. 7 is generated. In FIG. 7, reference numeral 701 denotes a gain correction value for each address of image data. For example, the gain correction value at the address (1, 2) of the image data is indicated by G (1, 2), and the data value at the address (1, 2) is multiplied by 1.8 according to the equation (Equation 2). It is determined. The gain correction value of the data of the pixel in the photometric area (area A) in FIG. 7 that is a pixel whose exposure time has not been changed to Ttvm [s] is determined to be “1.0”. Reference numerals 702, 703, and 704 denote areas corresponding to 405, 406, and 407 in FIG.

  Next, the operation of the shooting process in this embodiment shown in step S207 of FIG. 6 will be described with reference to the shooting process timing chart of FIG.

  In FIG. 8, VD represents a vertical synchronization signal, and is supplied from the timing generation unit 104 to the imaging unit 102 and the imaging control unit 103. There is one field from the VD fall to the next VD fall, and one piece of image data is acquired from the imaging unit 102 during this period.

  A quadrangle shown in the VD period schematically shows the exposure timing for each pixel of the image sensor controlled by the imaging control unit 103. Reference numerals 801 to 804 denote exposure times determined in accordance with the table in FIG. 5B in step S206 before the processing in step 802, and the areas A to D indicated by 405 to 407 in FIG. 4B. Each of the timings at which the pixels in the exposure start is shown. Reference numeral 805 denotes the timing of completion of exposure of pixels in each area. In the present embodiment, the imaging control unit 103 controls the imaging unit 102 so that the exposure of the pixels in all the regions ends at the same timing.

  Here, the exposure time of the pixel in the region B indicated by the width from 802 to 805, the exposure time of the pixel in the region C indicated by the width from 803 to 805, and the exposure time of the pixel in the region D indicated by the width from 804 to 805 All pixel exposure times exceed one field period. Therefore, as described in step S602 in FIG. 6, the exposure times of the pixels in the region B, the region C, and the region D are changed to the maximum exposure time Ttvm [s] that can be exposed within the VD period. Therefore, in the shooting processing of the present embodiment, the imaging control unit 103 determines that the exposure time indicated by the width from 806 to 805 for the region B, the exposure time indicated by the width from 807 to 805 for the region B, and from 808 for the region D. The imaging unit 102 is controlled so that the exposure time indicated by the width up to 805 is reached.

  In this embodiment, the case where the exposure time Ttv_a [s] of the pixels in the region A matches the maximum exposure time Ttvm [s] that can be exposed within the VD period has been described as an example. There is no need to

  Next, it is determined whether the process of step S602 has been performed (S604). When the process of step S602 is not performed (No in S604), the process proceeds to the process of step S208. When the process of step S602 is performed (Yes in S604), the image processing unit 105 performs the peripheral light amount drop correction process on the image data received from the imaging unit 102 based on the control of the system control unit 110. (S605).

  In the peripheral light amount drop correction process, the image processing unit 105 performs gain correction for each address of the image data under the control of the system control unit 110 based on the gain correction table created in step S603 (shown in FIG. 7 in the present embodiment). It is done by doing.

  As described above, according to the present embodiment, the exposure time is set so that the peripheral pixel of the image sensor is longer than the central pixel, but shorter than the VD period in consideration of a decrease in peripheral light amount. Control and shoot. When the exposure time of each pixel is controlled within the VD period and the drop in peripheral light amount cannot be corrected by the exposure time, the peripheral light amount is obtained by electrically amplifying the signal at the periphery of the screen of the acquired image data. Correct the drop. As a result, when it is necessary to acquire one image within one frame period, such as when recording a moving image, shooting in a shooting environment where the amount of subject light is low or when the amount of decrease in peripheral light amount by the lens barrel 101 is large. Even under conditions, it is possible to acquire image data in which peripheral light amount drop is corrected while reducing deterioration in image quality due to electrical amplification with respect to a signal at the periphery of the screen of image data.

  In the first and second embodiments, in the photographing process for photographing at different exposure times for each pixel, the image sensor is controlled so that the exposure starts at different timing for each pixel in each region and the exposure ends for all the pixels at the same time. However, the present invention is not limited to this. For example, the same effect can be obtained by controlling the image sensor so that all pixels start exposure at the same time and the exposure ends at different timing for each pixel in each region. Any other control may be used as long as it performs control with different exposure times for each pixel.

  In the first and second embodiments, the description has been made using the image sensor that performs the exposure start and the charge readout independently for each pixel. However, the image sensor is not necessarily controlled independently for each pixel. The same effect can be obtained even with an image sensor that starts exposure and reads out charges independently for each region composed of a plurality of pixels. The same effect can be obtained with a camera array in which a plurality of image sensors are arranged on a sensor surface used in a plenoptic camera by the same operation as the present invention.

  Although the present invention has been described in detail based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. included. A part of the above-described embodiments may be appropriately combined.

  In the processing of the above-described embodiment, a storage medium in which a program code of software that embodies each function is recorded may be provided to the system or apparatus. The functions of the above-described embodiments can be realized by the computer (or CPU or MPU) of the system or apparatus reading out and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. As a storage medium for supplying such a program code, for example, a floppy (registered trademark) disk, a hard disk, an optical disk, a magneto-optical disk, or the like can be used. Alternatively, a CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like can be used.

  The functions of the above-described embodiments are not only realized by executing the program code read by the computer. Including the case where the OS (operating system) running on the computer performs part or all of the actual processing based on the instruction of the program code, and the functions of the above-described embodiments are realized by the processing. It is.

  Further, the program code read from the storage medium may be written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. After that, the CPU of the function expansion board or function expansion unit performs part or all of the actual processing based on the instruction of the program code, and the functions of the above-described embodiments are realized by the processing. Is also included.

DESCRIPTION OF SYMBOLS 100 ... Imaging device 101 ... Lens barrel part 102 ... Imaging part 103 ... Imaging control part 104 ... Timing generation part 105 ... Image processing part 106 ... Memory 107 ... Display part 108 ... Recording control part 109 Recording medium 110 System control unit 111 Lens barrel control unit 112 Lens barrel state detection unit 113 Operation unit 114 Power source control unit 115 Power source unit

Claims (6)

Subject light incident through the imaging lens
It has at least two or more areas composed of one or more pixels, starts exposure independently from each other in units of the areas, and reads image information acquired by exposure all at once, or in all areas The exposure is started in a batch, and the image information acquired by exposure is read out independently from each other in the region unit, or the exposure is started independently from each other in the region unit, and the image information acquired by the exposure is read out in the region unit. Imaging means for reading out independently of each other;
Imaging control means for controlling the imaging means to start exposure and read out image information;
Photometric means for determining exposure conditions in at least one or more of the regions located near the center of the light receiving surface of the imaging means;
Lens state detection means for acquiring information on the zoom position and aperture state of the imaging lens;
An exposure time determination means for determining an exposure time for each region based on information by the lens state detection means and an exposure condition by the photometry means;
The imaging apparatus, wherein the imaging control unit controls the imaging unit so that exposure is performed with the exposure time of the area unit determined by the exposure time determination unit. The exposure time determining means determines the exposure time of the area unit located near the periphery to be longer than the exposure time of the area unit located near the center of the light receiving surface of the imaging means. The imaging apparatus according to claim 1. Timing control means for transmitting a timing signal for timing control to the imaging means and the imaging control means;
Whether any one of the exposure times determined for each region of the imaging means determined by the exposure time determination means is longer than one cycle of the timing signal from the timing control means Having an exposure time excess determination means for determining
2. The exposure time determining means changes the exposure time to a predetermined exposure time when the exposure time excess judging means determines that the exposure time is longer than one cycle of the timing signal. Or the imaging device of Claim 2. 4. The imaging apparatus according to claim 3, wherein the predetermined exposure time is a longest time that can be taken within one cycle of the timing signal from the timing control means. Image correction means for performing correction by image processing on the image information acquired by the imaging means;
When the exposure time determined for the region unit of the imaging means by the image correction means is considered to be longer than one cycle of the timing signal from the timing control means, the exposure time The imaging apparatus according to claim 1, wherein the image information acquired from the region is corrected by applying a predetermined gain. The predetermined gain is considered to be longer than one cycle of the timing signal by the exposure time excess determination unit with respect to the exposure time determined for the region unit of the imaging unit in the exposure time determination unit, 6. The imaging apparatus according to claim 5, wherein the imaging apparatus is determined in accordance with a ratio to the predetermined exposure time to be changed.