JP2009027512A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of suppressing deterioration in the picture quality of a motion image. <P>SOLUTION: A plurality of light receiving elements are grouped by being allocated to two groups, exposure times of the light receiving elements are controlled at each group, and predetermined information for controlling the exposure times is detected from image information obtained by imaging, and it is controlled which of operation modes should be operated out of a first operation mode which controls an exposure time of the light receiving element belonging to one prescribed group so as to reach a prescribed time, and acquires a signal only form the light receiving element belonging to one group, and a second operation mode which controls exposure times of the light receiving elements belonging to the two groups are made to differ from each other between the groups, and acquires signals from the light receiving elements belonging to the two groups, according to the detected prescribed information. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging device, and more particularly to an imaging device that improves the image quality of moving images.

  Some digital cameras can capture moving images in addition to still images. As a technique in a digital camera capable of capturing such a moving image, Patent Document 1 discloses a technique for improving display sensitivity during a movie mode operation of a solid-state imaging device. Patent Document 2 discloses a technique for improving the image quality and functions of an imaging apparatus using a CCD that is also used as a still image moving image. Further, Patent Document 3 discloses a solid-state imaging device and a signal readout method that can increase the degree of one-layer thinning over conventional thinning.

  When shooting a moving image, if the illuminance of the object scene is low, the image quality is adjusted by adding pixel signals, increasing the gain, and reducing the frame rate. In addition, the image quality is adjusted by changing the pixel to be read for each frame and extending the exposure time by not performing the electronic shutter.

Furthermore, when a moving image is shot, a plurality of light receiving elements constituting the image sensor are allocated to two groups, and in a digital camera capable of controlling the exposure time of the light receiving elements for each group, the light receiving elements belonging to the two groups A first operation mode in which the exposure time is controlled to be different between groups, and signals are obtained from light receiving elements belonging to two groups, and signals are obtained only from light receiving elements belonging to one predetermined group. Some of the two operation modes can operate in one of the operation modes.
JP 2001-111894 A JP 2003-189183 A JP 2000-286408 A

  In such a technical background, in the pixel signal addition as described above, if the addition is excessive, the resolution decreases. Further, the S / N deteriorates due to gain increase. If the frame rate is further reduced, the image quality of the moving image deteriorates.

  Also, in the case of a digital camera that can be controlled in the two operation modes described above, the image quality of image data captured in one of the operation modes is always compared with the image quality of the image mode captured in the other operation mode. Since the image quality is not high, the image quality may deteriorate depending on the subject.

  As described above, the conventional technique has a problem that the image quality of the captured moving image deteriorates.

  In view of the above problems, an object of the present invention is to provide an imaging device that suppresses deterioration of the image quality of a moving image.

  In order to achieve the above object, the invention of claim 1 groups the light receiving elements by allocating an imaging element including a plurality of light receiving elements for imaging a subject and the plurality of light receiving elements to two groups. Exposure control means for controlling the exposure time of the light receiving element for each group; detection means for detecting predetermined information for controlling the exposure time from image information obtained by imaging with the imaging element; A first operation mode for controlling the exposure time of the light receiving elements belonging to one predetermined group by the exposure control means to be a predetermined time, and acquiring a signal only from the light receiving elements belonging to the one group; and The exposure control means controls the exposure time of the light receiving elements belonging to the two groups to be different between the groups, and the light receiving elements belonging to the two groups. Of the second operation mode for acquiring a signal from, if they work in all operating modes, and a control means for controlling in response to the predetermined information detected by the detecting means.

  Here, in the invention of claim 1, the image sensor includes a plurality of light receiving elements for imaging a subject, and the exposure control unit groups the light receiving elements into two groups, and groups the light receiving elements. The exposure time of the light receiving element is controlled for each group, the detection means detects predetermined information for controlling the exposure time from image information obtained by imaging with the imaging element, and the control means detects the exposure control. A first operation mode in which the exposure time of the light receiving elements belonging to one group predetermined by the means is controlled to be a predetermined time, and a signal is obtained only from the light receiving elements belonging to the one group, and the exposure control Means for controlling the exposure time of the light receiving elements belonging to the two groups to be different between the groups, and receiving signals from the light receiving elements belonging to the two groups. Of the second operation mode for obtaining, whether to operate in either mode, controlled according to the predetermined information detected by the detecting means. As described above, since control is performed according to predetermined information obtained by imaging the subject, it is possible to shoot in an operation mode suitable for the subject, so that it is possible to suppress deterioration in image quality in a moving image.

  Further, according to the present invention, as in the second aspect of the invention, the detection unit detects occurrence of flicker from the image information as the predetermined information, and the control unit generates the flicker by the detection unit. If the exposure time is detected, control is performed to operate in the first operation mode, and the exposure control means further controls the exposure time to be an exposure time that matches the flicker frequency. You may make it do.

  According to the second aspect of the present invention, since the occurrence of flicker can be suppressed, it is possible to suppress the deterioration of the image quality of the moving image.

  According to the present invention, as in the invention of claim 3, the detection means detects a human face from the image information as the predetermined information, and the control means detects the face by the detection means. In such a case, control may be performed so as to operate in the second operation mode.

  According to the invention of claim 3, since the dynamic range can be increased in the second operation mode as compared with the first operation mode, the overexposure and underexposure of the face are suppressed. It is possible to suppress degradation of the image quality of the moving image.

  According to a fourth aspect of the present invention, when the detection means detects backlight from the image information as the predetermined information, and the control means detects the backlight by the detection means. Controls to operate in the second operation mode.

  According to the invention of claim 4, the second operation mode can increase the dynamic range as compared with the first operation mode, so that whiteout and blackout can be suppressed. Therefore, it is possible to suppress the deterioration of the image quality of the moving image.

  Further, according to the present invention, as in the fifth aspect of the invention, the detection unit detects smear from the image information as the predetermined information, and the control unit detects smear by the detection unit. Controls to operate in the second operation mode.

  According to the invention of claim 5, since the dynamic range can be increased in the second operation mode as compared with the first operation mode, overexposure and blackout can be suppressed. Therefore, it is possible to suppress the deterioration of the image quality of the moving image.

  According to a sixth aspect of the present invention, as in the sixth aspect of the invention, the detection means detects a subject moving at a speed higher than a predetermined speed from the image information as the predetermined information, and the control means is the detection means. Thus, when a subject moving at a speed equal to or higher than the predetermined speed is detected, control may be performed so as to operate in the first operation mode.

  According to the sixth aspect of the present invention, when a moving body moving at a speed equal to or higher than a predetermined speed is detected, the second operation is performed in the first operation mode in which the exposure time is constant every predetermined time. Compared with the case of operating in the operation mode, it is possible to suppress the deterioration of the image quality of the moving image.

  According to the present invention, it is possible to provide an imaging apparatus that can suppress deterioration of image quality in a moving image.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  Next, with reference to FIG. 1, an external configuration of the digital camera 10 according to the present embodiment will be described. A front surface of the digital camera 10 includes a lens 21 that is an optical member for forming a subject image, a viewfinder 20 that is used to determine the composition of the subject to be photographed, and a strobe 44. Further, on the upper surface of the digital camera 10, a release button (so-called shutter button) 56A that is pressed when shooting is performed, and a power switch 56B are provided.

  Note that the release button 56A of the digital camera 10 according to the present embodiment is pressed down to an intermediate position (hereinafter referred to as “half-pressed state”) and to a final pressed position beyond the intermediate position. A two-stage pressing operation of a state (hereinafter referred to as a “fully pressed state”) can be detected.

  In the digital camera 10, the brightness of the subject is measured by pressing the release button 56 </ b> A halfway, and an AE (Automatic Exposure) function is activated based on the measured brightness of the subject. After the shutter speed and the aperture state) are set, the AF (Auto Focus) function is activated to control the focus, and then exposure (photographing) is performed when the shutter button is fully pressed.

  On the other hand, on the back of the digital camera 10, the eyepiece of the finder 20 described above, the LCD 38 for displaying a photographed subject image, a menu screen, and the like, a photographing mode as a photographing mode, and a photographing mode are obtained. And a mode changeover switch 56C that is slid to be set to any one of the reproduction modes, which is a mode for reproducing and displaying the subject image displayed on the LCD 38.

  Further, on the back surface of the digital camera 10, a cross cursor button 56D and a forced light emission switch 56E that is pressed when setting the forced light emission mode, which is a mode for forcibly causing the flash 44 to emit light during photographing, are further provided. It has been.

  The cross-cursor button 56D includes four arrow keys that indicate four moving directions of up, down, left, and right in the display area of the LCD 38, and a determination key that exists in the center of the arrow keys. ing.

  Next, the configuration of the electrical system of the digital camera 10 according to the present embodiment will be described with reference to FIG.

  The digital camera 10 includes an optical unit 22 that includes the lens 21 described above, a charge coupled device (hereinafter referred to as “CCD”) 24 that is an imaging device disposed behind the optical axis of the lens 21, and And an analog signal processing unit 26 that performs various analog signal processing on the input analog signal.

  The digital camera 10 also performs an analog / digital converter (hereinafter referred to as “ADC”) 28 that converts an input analog signal into digital data, and performs various digital signal processing on the input digital data. And a digital signal processing unit 30.

  The digital signal processing unit 30 has a built-in line buffer having a predetermined capacity, and also performs control to directly store the input digital data in a predetermined area of the memory 48 described later.

  The output terminal of the CCD 24 is connected to the input terminal of the analog signal processing unit 26, the output terminal of the analog signal processing unit 26 is connected to the input terminal of the ADC 28, and the output terminal of the ADC 28 is connected to the input terminal of the digital signal processing unit 30. . Accordingly, the analog signal indicating the subject image output from the CCD 24 is subjected to predetermined analog signal processing by the analog signal processing unit 26, converted into digital image data by the ADC 28, and then input to the digital signal processing unit 30.

  On the other hand, the digital camera 10 is obtained by photographing, an LCD interface 36 that generates a signal for displaying an object image, a menu screen, and the like on the LCD 38 and supplies the signal to the LCD 38, a CPU 40 that controls the operation of the entire digital camera 10. A memory 48 that stores digital image data and the like, and a memory interface 46 that controls access to the memory 48 are included. In this embodiment, the analog signal and digital image data are used as image information.

  Further, the digital camera 10 includes an external memory interface 50 for enabling the portable memory card 52 to be accessed by the digital camera 10, and a compression / decompression processing circuit 54 for performing compression processing and decompression processing on the digital image data. It is configured to include.

  In the digital camera 10 of the present embodiment, any one or more of VRAM (Video RAM), SRAM or DRAM, and flash memory is used as the memory 48, and smart media (Smart Media (registered) is used as the memory card 52. Trademark)).

  The digital signal processing unit 30, the LCD interface 36, the CPU 40, the memory interface 46, the external memory interface 50, and the compression / decompression processing circuit 54 are connected to each other via a system bus BUS. Therefore, the CPU 40 controls the operation of the digital signal processing unit 30, controls the operation of the compression / decompression processing circuit 54, displays various information via the LCD interface 36 to the LCD 38, and the memory interface 46 to the memory 48 and the memory card 52. And access via the external memory interface 50.

  On the other hand, the digital camera 10 includes a timing generator 32 that mainly generates a timing signal for driving the CCD 24 and supplies the timing signal to the CCD 24, and the driving of the CCD 24 is controlled by the CPU 40 via the timing generator 32. Further, direct control of the electronic shutter described later is performed by the timing generator 32.

  Further, the digital camera 10 is provided with a motor drive unit 34, and driving of a focus adjustment motor, a zoom motor, and an aperture drive motor (not shown) provided in the optical unit 22 is also controlled by the CPU 40 via the motor drive unit 34. The

  In other words, the lens 21 according to the present embodiment has a plurality of lenses, is configured as a zoom lens that can change (magnify) the focal length, and includes a lens driving mechanism (not shown). The lens drive mechanism includes the focus adjustment motor, the zoom motor, and the aperture drive motor. These motors are each driven by a drive signal supplied from the motor drive unit 34 under the control of the CPU 40.

  Further, the release button 56A, the power switch 56B, the mode changeover switch 56C, the cross cursor button 56D, and the forced light emission switch 56E (generally referred to as “operation unit 56” in the figure) are connected to the CPU 40, and the CPU 40. Can always grasp the operation state of the operation unit 56.

  In addition, the digital camera 10 includes a charging unit 42 that is interposed between the strobe 44 and the CPU 40 and charges power for causing the strobe 44 to emit light under the control of the CPU 40. Further, the strobe 44 is also connected to the CPU 40, and the light emission of the strobe 44 is controlled by the CPU 40.

  Next, an overall operation at the time of shooting of the digital camera 10 according to the present embodiment will be briefly described.

  First, the CCD 24 performs photographing through the optical unit 22 and sequentially outputs analog signals for R (red), G (green), and B (blue) indicating the subject image to the analog signal processing unit 26. The analog signal processing unit 26 performs analog signal processing such as correlated double sampling processing on the analog signal input from the CCD 24 and sequentially outputs the analog signal to the ADC 28.

  The ADC 28 converts the R, G, and B analog signals input from the analog signal processing unit 26 into 12-bit R, G, and B signals (digital image data) and sequentially outputs them to the digital signal processing unit 30. To do. The digital signal processing unit 30 accumulates digital image data sequentially input from the ADC 28 in a built-in line buffer and temporarily stores the digital image data directly in a predetermined area of the memory 48.

  Digital image data stored in a predetermined area of the memory 48 is read out by the digital signal processing unit 30 under the control of the CPU 40, and a white balance is adjusted by applying a digital gain according to a predetermined physical quantity. Processing and sharpness processing are performed to generate digital image data of predetermined bits, for example, 8 bits.

  The digital signal processing unit 30 performs YC signal processing on the generated digital image data of predetermined bits to generate a luminance signal Y and chroma signals Cr and Cb (hereinafter referred to as “YC signal”), and a YC signal. Are stored in an area different from the predetermined area of the memory 48.

  The LCD 38 is configured to display a moving image (through image) obtained by continuous photographing by the CCD 24 and can be used as a finder. When the LCD 38 is used as a finder, the LCD 38 is generated. The YC signals thus output are sequentially output to the LCD 38 via the LCD interface 36. As a result, a through image is displayed on the LCD 38.

  Here, when the release button 56A is half-pressed by the user, after the AE function is activated and the exposure state is set as described above, the AF function is activated and focus control is performed, and then the fully-pressed state is continued. In this case, the YC signal stored in the memory 48 at this time is compressed in a predetermined compression format (in this embodiment, JPEG format) by the compression / decompression processing circuit 54 and then passed through the external memory interface 50. To the memory card 52.

  In addition, the shooting of moving images basically repeats the shooting of still images as described above. Specifically, as will be described later, an electronic shutter is used, and a frame is successively captured at predetermined time intervals. Image data is obtained.

  Next, grouping of the light receiving elements and two operation modes will be described. FIG. 3 is a diagram showing a CCD 24 including a plurality of light receiving elements. FIG. 2 is a schematic diagram showing a first operation mode in which signals are acquired only from light receiving elements belonging to one predetermined group. In the figure, two CCDs 24 are shown to indicate a light receiving element that acquires charges in the first frame and the second frame.

  In the figure, each rectangle described as “R (Red)”, “G (Green)”, and “B (Blue)” corresponds to a light receiving element. Further, the electric charges output from the respective light receiving elements sequentially move downward, and are output to the analog signal processing unit 26 by the HCCD which is a horizontal transfer path.

  Further, as shown in the figure, the group in the present embodiment is a group of light receiving elements arranged in the horizontal direction indicated by “V1A, V2A, V3A, V4A” (hereinafter referred to as group A). , “V1B, V2B, V3B, V4B” and another group of light receiving elements arranged in the horizontal direction (hereinafter referred to as group B). As described above, in this embodiment, the light receiving elements are grouped by allocating a plurality of light receiving elements to two groups for each electrode from which charges are read. The timing generator 32 controls the exposure time of the light receiving element for each group.

  VNX such as V1A (N is 1 or 2, X is A or B) indicates an end point to which a signal is applied. In the present embodiment, for example, “V1A, V2A” shown in the figure, a voltage is applied to one row of light receiving elements at two end points so as to correspond to one row of light receiving elements. Applied.

  In the figure, each group includes only two rows of light receiving elements. However, the number of light receiving elements is not limited to two, and the value varies depending on the resolution of the CCD 24 and the like.

  In the first operation mode, as shown in the figure, signals are acquired only from light receiving elements belonging to group A in any frame. FIG. 4 shows a time chart showing signals in the first operation mode.

  In the figure, a vertical synchronizing signal, a signal applied to each end point VNX, and an electronic shutter pulse are shown. The vertical synchronization signal is a signal indicating a section for one frame.

  Of the signals applied to the respective end points VNX, a long vertical bar indicates a signal for pushing out charges on the vertical transfer path, and a short vertical bar indicates a signal for moving charges on the vertical transfer path. In the electronic shutter pulse, the vertical bar indicates a signal when the electronic shutter pulse is output.

  As shown in the figure, in the first operation mode, a signal is applied only to the light receiving elements belonging to group A. The exposure time is also a predetermined time.

  Next, the second operation mode will be described. FIG. 5 is a diagram showing a CCD 24 including a plurality of light receiving elements as in FIG. FIG. 6 is a schematic diagram showing a second operation mode in which the light receiving elements belonging to the two groups are controlled to have different exposure times and signals are acquired from the light receiving elements belonging to the two groups. In the figure, four CCDs 24 are shown to indicate a light receiving element that acquires charges in the first to fourth frames.

  In the same figure, each rectangle described as “R”, “G”, “B” corresponds to the light receiving element, and the electric charges output from each light receiving element sequentially move downward, The output to the analog signal processing unit 26 by the HCCD which is a horizontal transfer path is the same as in FIG.

  Further, as in FIG. 3, the groups in the second operation mode are the groups A including the light receiving elements arranged in the horizontal direction indicated by “V1A, V2A, V3A, V4A” and “V1B, V2B, V3B”. , V4B ”and another group B composed of light receiving elements arranged in the horizontal direction.

  The VNX such as V1A is the same as that shown in FIG. 3 and only two rows of light receiving elements are shown in each group. Of course, the number is not limited to two. The values are different as in FIG.

  In the second operation mode, as shown in the figure, signals are obtained from light receiving elements belonging to group A in frames 1 and 3, and signals are obtained from light receiving elements belonging to group B in frames 2 and 4. To do. The signals obtained from the light receiving elements belonging to each group in this way are synthesized by the digital signal processing unit 30.

  FIG. 6 shows a time chart showing signals in the second operation mode. Each signal shown in FIG. 6 is the same as that described in FIG.

  As shown in the figure, in the second operation mode, signals are alternately applied to the light receiving elements belonging to each group. The exposure times of the light receiving elements belonging to each group are different. Specifically, first, when the output of the electronic shutter pulse ends, charge accumulation is started in each light receiving element (see “Charge accumulation start”). Thereafter, the charge accumulated in the light receiving elements belonging to group B at time Tb is pushed out to the vertical transfer path. Therefore, the exposure time of the light receiving elements belonging to group B is the time from the end of the output of the electronic shutter pulse to the time Tb.

  Thereafter, the charge accumulated in the light receiving elements belonging to group A at time Ta is pushed out to the vertical transfer path. Therefore, the exposure time of the light receiving elements belonging to group A is the time from the end of the output of the electronic shutter pulse to the time Ta.

  In this way, by changing the exposure time for each group, the light receiving elements belonging to each group can be handled as light receiving elements with apparently different sensitivities. At this time, a signal obtained from a light receiving element belonging to a group having a short exposure time is handled as low luminance information.

  In this embodiment, since the exposure time of the light receiving elements belonging to group A is set to four times the exposure time of the light receiving elements belonging to group B, the dynamic range in the second operation mode is the first operation time. Compared to the dynamic range in the mode, the dynamic range can be 400%.

  The above is the description of the two operation modes. Next, a process for detecting predetermined information from image data obtained by imaging with the CCD 24 and controlling which operation mode of the two operation modes is controlled according to the detected result. This will be described with reference to a flowchart. Note that the flowchart described below is executed by the CPU 40. Each flowchart shows processing that is performed when moving image shooting is started, for example, when moving image mode starts or when moving image shooting is started.

  First, referring to FIG. 7, processing for detecting occurrence of flicker from image data as predetermined information and controlling to operate in the first operation mode when it is detected that flicker has occurred. Will be described.

  First, in step 101, flicker detection processing is performed. In the next step 102, it is determined whether or not flicker has occurred. If an affirmative determination is made in step 102, control is performed in step 103 so as to operate in the first operation mode. Further, the exposure time is adjusted to match the flicker frequency. On the other hand, if a negative determination is made in step 102, control is performed in step 104 so as to operate in the second operation mode.

  Since this process can suppress the occurrence of flicker, it is possible to suppress the deterioration of the image quality of the moving image.

  Note that the flicker detection process in step 101 may be a conventionally used process, but in the present embodiment, the flicker detection process is performed using the luminance of the image indicated by the image data of each frame. Specifically, the brightness of the image indicated by the image data of a certain frame is measured, the brightness of the image indicated by the image data of the next frame is measured, and the difference in the brightness is equal to or greater than a predetermined value. Judge as flicker.

  Next, a process of detecting a human face from image data as predetermined information and controlling to operate in the second operation mode when a face is detected will be described with reference to FIG.

  First, in step 201, face detection processing is performed. In the next step 202, it is determined whether or not a face has been detected. If an affirmative determination is made in step 202, control is performed in step 203 so as to operate in the second operation mode. On the other hand, if a negative determination is made in step 202, control is performed in step 204 so as to operate in the first operation mode.

  With this process, when a face is detected, the operation is performed in the second operation mode having a high dynamic range, so that the face can be prevented from being overexposure or underexposure, and the moving image quality can be prevented from being deteriorated. be able to.

  Note that the face detection process in step 201 may use a conventionally used process, but in the present embodiment, a certain amount of flesh color clusters existed in the image indicated by the image data. If the face is judged.

  Next, referring to FIG. 9, processing for detecting backlight from image data as predetermined information and controlling to operate in the second operation mode when the backlight is detected will be described.

  First, in step 301, backlight detection processing is performed. In the next step 302, it is determined whether backlight is detected. If an affirmative determination is made in step 302, control is performed in step 303 so as to operate in the second operation mode. On the other hand, if a negative determination is made in step 302, control is performed in step 304 so as to operate in the first operation mode.

  By this process, when the backlight is detected, the operation is performed in the second operation mode having a high dynamic range, so that it is possible to suppress overexposure and underexposure and to suppress deterioration in the image quality of the moving image. it can.

  Note that the backlight detection process in step 301 may use a conventionally used process. However, in this embodiment, there is a cluster of pixels having a luminance of a predetermined level or more in the image indicated by the image data. If it is determined to be backlit.

  Next, a process for detecting smear from image data as predetermined information and controlling to operate in the second operation mode when smear is detected will be described with reference to FIG.

  First, in step 401, smear detection processing is performed. In the next step 402, it is determined whether smear has been detected. If an affirmative determination is made in step 402, control is performed in step 403 so as to operate in the second operation mode. On the other hand, if a negative determination is made in step 402, control is performed in step 404 so as to operate in the first operation mode.

  With this process, when smear is detected, the operation is performed in the second operation mode having a high dynamic range, so it is possible to suppress overexposure and underexposure, and to suppress deterioration in the image quality of the moving image. it can.

  Note that the smear detection process in step 401 may be a conventionally used process, but in the present embodiment, detection is performed using an OB (Optical Black) region as shown in FIG. Is done. Specifically, first, the OB area is an area of the CCD 24 where no light enters. When smear occurs, the charge is detected from the OB region by mixing the charge into the vertical transfer path as shown in FIG. Therefore, for example, by determining smear when charge of a certain level or more is detected in image data corresponding to the OB area (in this case, an analog signal), smear can be detected using the OB area.

  Next, referring to FIG. 12, when a subject moving at a speed equal to or higher than a predetermined speed is detected from image data as predetermined information, and a subject moving at a speed higher than a predetermined speed is detected, the first operation is performed. Processing for controlling to operate in the mode will be described.

  First, in step 501, a moving object detection process for detecting a moving object moving at a speed equal to or higher than a predetermined speed is performed. In the next step 502, it is determined whether or not a moving object moving at a speed equal to or higher than a predetermined speed is detected. If an affirmative determination is made in step 502, control is performed in step 503 so as to operate in the first operation mode. On the other hand, if a negative determination is made in step 502, control is performed in step 504 so as to operate in the second operation mode.

  When a moving body moving at a speed higher than a predetermined speed is detected and operating in the second operation mode, the exposure time of the light receiving elements belonging to the two groups is different, resulting in an unnatural moving image. Therefore, when a moving body moving at a speed equal to or higher than a predetermined speed is detected by this processing, since the exposure time operates in the first operation mode that is constant every predetermined time, the operation is performed in the second operation mode. Compared to the case, it is possible to suppress the deterioration of the image quality of the moving image.

  Note that the processing for detecting a subject moving at a speed equal to or higher than the predetermined speed in the step 501 may be a conventionally used processing, but in the present embodiment, by the difference calculation of the image indicated by the image data. The moving object and its speed are detected.

  As shown in each of the flowcharts described above, the CPU 40 controls the exposure time of the light receiving elements belonging to one predetermined group (group A) to be a predetermined time, so that the one group (group A) is assigned. A first operation mode in which signals are acquired only from the light receiving elements belonging thereto, and exposure control means (timing generator 32) is controlled so that the exposure times of the light receiving elements belonging to the two groups (groups A and B) are different between the groups. Then, a detection means (detection process shown in each flowchart) indicates which one of the second operation modes for acquiring signals from the light receiving elements belonging to the two groups (groups A and B). Control is performed according to the predetermined information detected by.

  The processing flow of each flowchart described above is an example, and the processing order may be changed, new steps may be added, or unnecessary steps may be deleted without departing from the scope of the present invention. Needless to say, you can.

An appearance configuration of the digital camera according to the present embodiment will be described. The configuration of the electrical system of the digital camera according to this embodiment will be described. It is a figure which shows CCD containing a some light receiving element (1st operation mode). It is a figure which shows the time chart which shows the signal in a 1st operation mode. It is a figure which shows CCD containing a some light receiving element (2nd operation mode). It is a figure which shows the time chart which shows the signal in a 2nd operation mode. It is a flowchart which shows a process when a flicker is detected. It is a flowchart which shows a process when a face is detected. It is a flowchart which shows a process when a backlight is detected. It is a flowchart which shows a process when a smear is detected. It is a figure which shows OB area | region and a smear. It is a flowchart which shows a process when the to-be-photographed object moved at the speed more than predetermined speed is detected.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Digital camera 26 Analog signal processing part 30 Digital signal processing part 32 Timing generator 34 Motor drive part 40 CPU
46 Memory interface 48 Memory

Claims (6)

An image sensor including a plurality of light receiving elements for imaging a subject;
Exposure control means for grouping the light receiving elements by allocating the plurality of light receiving elements to two groups, and controlling the exposure time of the light receiving elements for each group;
Detecting means for detecting predetermined information for controlling the exposure time from image information obtained by imaging with the imaging element;
A first operation mode for controlling the exposure time of the light receiving elements belonging to one of the predetermined groups by the exposure control means to be a predetermined time, and acquiring a signal only from the light receiving elements belonging to the one group; and The exposure control means controls the exposure time of the light receiving elements belonging to the two groups to be different between the groups, and any one of the second operation modes for acquiring signals from the light receiving elements belonging to the two groups Control means for controlling whether to operate in an operation mode according to the predetermined information detected by the detection means;
An imaging apparatus having The detection means detects occurrence of flicker from the image information as the predetermined information,
The control means controls to operate in the first operation mode when the detection means detects that the flicker is generated, and also sets the exposure time to the exposure time by the exposure control means. The image pickup apparatus according to claim 1, further controlling so that an exposure time is adjusted to a flicker frequency. The detection means detects a human face from the image information as the predetermined information,
The imaging apparatus according to claim 1, wherein the control unit performs control so as to operate in the second operation mode when a face is detected by the detection unit. The detection means detects backlight from the image information as the predetermined information,
The imaging apparatus according to claim 1, wherein the control unit performs control so as to operate in the second operation mode when backlight is detected by the detection unit. The detection means detects smear from the image information as the predetermined information,
The imaging apparatus according to claim 1, wherein the control unit controls to operate in the second operation mode when smear is detected by the detection unit. The detection means detects a subject moving at a speed equal to or higher than a predetermined speed from the image information as the predetermined information,
The imaging apparatus according to claim 1, wherein the control unit controls to operate in the first operation mode when a subject moving at a speed equal to or higher than the predetermined speed is detected by the detection unit.