JP2008118378A - Photographing device and its driving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent noise due to driving of an imaging lens from being caused in a photographed image. <P>SOLUTION: An imaging apparatus comprises: an imaging device 107 having a pixel part in which pixels are arrayed in the shape of a two-dimensional matrix; the imaging lens 101 provided to guide an optical image from an object to the imaging device 107; an imaging signal processing circuit part 108 for reading a first signal from a portion of an pixel area in the pixel part, reading a second signal from a pixel area different from the portion of the pixel area at timing different from that of the first signal and generating image data on the basis of the first signal; a lens driving part 102 for driving the imaging lens 101 on the basis of the second signal; and a whole controlling-operating part 115 for controlling the driving of the imaging lens 101 by the lens driving part 102 while reading the second signal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is an imaging device including an xy addressing type imaging device having a pixel portion in which pixels are arranged in a two-dimensional matrix, and an imaging lens provided to guide an optical image from a subject to the imaging device. The present invention relates to an apparatus and a driving method thereof.

  In general, CCD sensors and CMOS sensors are well known as solid-state imaging devices. The CCD sensor sequentially transfers charges photoelectrically converted by a photodiode (hereinafter referred to as “PD”) like a bucket relay, and the charge amount is converted to a voltage by a floating diffusion amplifier (hereinafter referred to as “FD amplifier”) at the final stage. Convert to quantity.

  On the other hand, in each pixel of the CMOS sensor, the PD and the FD exist mainly in pairs, and are converted to a voltage amount by the FD amplifier in the pixel portion. In the CMOS sensor, since each pixel converts the voltage into a voltage, the variation of each pixel is a problem only for that pixel, and the signal of other pixels is not adversely affected. Therefore, if the variation of each pixel is corrected systematically, Manufacturing difficulty is not as difficult as CCD sensors. Prior art documents relating to this CMOS sensor include, for example, Patent Document 1 and Patent Document 2 below.

  When such a (solid) image sensor is used for moving image shooting, an electronic shutter function is indispensable. This means that by controlling the accumulation time (exposure time) in the PD according to the brightness of the subject to be photographed, control is performed so that the photographed image signal has an appropriate signal amount.

  Recently, the CCD sensor and the CMOS sensor have been increased in the number of pixels, and the clock frequency for reading has become faster in order to shorten the reading time. In such a situation, if control is performed in which a large amount of current flows as in lens driving, the reference voltage of the output amplifier of the image sensor fluctuates, and noise is added to the captured image. In view of this problem, Patent Document 3 below proposes a technique for performing control so that the timing at which the drive voltage of the USM motor falls sharply, particularly during the blanking period of 1H during image reading.

JP 2000-201300 A JP 2002-209144 A JP 2000-47090 A

  In order to realize an electronic shutter with a CCD sensor, a technique for discarding charges in the depth direction of a silicon substrate, called V-sub as a front curtain of a single-lens reflex camera, and a vertical for reading as a rear curtain. A technique for shifting charge from a PD to a CCD (hereinafter referred to as “VCCD”) from the PD at the same time is considered. This is divided into an accumulation time from the first curtain to the second curtain and a read time of the VCCD and is a sequential movement.

  On the other hand, in order to realize an electronic shutter in a CMOS sensor, there is a method called rolling, but this does not cut out the entire screen at the same time on the entire screen, but has the same time property only in units such as rows and columns. Because there is no subject, the subject flows and appears. In other words, focusing on one row, the maximum accumulation time is between the previous frame read and the current frame read, and the PD reset pulse is applied during that time to enable control of the accumulation time. . However, in this case, unlike the CCD sensor, the readout period and the accumulation period cannot be separated without a sequential movement.

  FIG. 8 is a schematic diagram showing an outline of each timing of readout of a CMOS sensor, monitor display, and lens driving in a general imaging apparatus. Here, in the readout of the CMOS sensor, each line segment indicates a readout period of each frame in the moving image.

  The CMOS sensor is driven to roll and an image signal is read out. Regarding the monitor display, the read image signal is subjected to signal processing for each frame and displayed on the monitor. Regarding lens driving, the read image signal is subjected to AF calculation processing for each frame, and lens driving is performed according to the calculation result.

  In reading with such rolling driving, reading from the CMOS sensor is always continued. Therefore, reading of the image signal and lens driving always overlap regardless of the timing of driving the lens. That is, in the conventional imaging device that performs reading by rolling driving, readout of the image signal and lens driving overlap, and it is difficult to prevent noise caused by driving of the imaging lens from occurring in the captured image. .

  In addition, when trying to match the voltage fluctuation timing of the motor drive in the lens during the 1H blanking period, if the image signal readout method changes, it is necessary to change the drive timing of the motor accordingly, and the motor is made efficient. I can't move well.

  Further, when there are many combinations of lenses and cameras as in a single-lens reflex camera, it is almost impossible to match the image signal readout method and the lens drive timing so that all combinations can be handled.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an imaging apparatus and a driving method thereof that prevent noise caused by driving of an imaging lens from occurring in a captured image.

  An imaging device according to the present invention includes an imaging device having a pixel portion in which pixels are arranged in a two-dimensional matrix, an imaging lens provided to guide an optical image from a subject to the imaging device, Reading means for reading a first signal from a part of the pixel area and reading a second signal from a pixel area different from the part of the pixel area at a timing different from the first signal; Image data generating means for generating image data based on the first signal; imaging lens driving means for driving the imaging lens based on the second signal; and the reading means for reading the second signal. Control means for performing control to drive the imaging lens by the imaging lens driving means during a period when the imaging lens is performed.

  An image pickup apparatus driving method according to the present invention includes an image pickup device having a pixel portion in which pixels are arranged in a two-dimensional matrix, and an image pickup lens provided to guide an optical image from a subject to the image pickup device. A method for driving an imaging apparatus that reads a first signal from a part of a pixel area of the pixel unit and differs from the first signal from a pixel area different from the part of the pixel area. A readout step for reading out the second signal at timing, an image data generation step for generating image data based on the first signal, and an imaging lens drive for driving the imaging lens based on the second signal And a control step for performing control to drive the imaging lens by the imaging lens driving step during a period in which the second signal is read in the reading step. And a flop.

  According to the present invention, it is possible to prevent noise caused by driving of the imaging lens from occurring in a captured image.

  Further, according to the present invention, when reading out the first signal, pixels in the partial pixel region are thinned out and read out, so that the reading period of the first signal can be shortened. Accordingly, when the signal readout period in the pixel portion is constant, the readout period of the second signal can be lengthened compared to the case where the readout is performed without thinning out the first signal. The imaging lens can be driven over a long period of time.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, in the embodiment of the present invention, an example in which a digital camera is applied as an imaging apparatus according to the present invention will be described.

FIG. 1 is a block diagram showing a schematic configuration of a digital camera (imaging device) 100 according to an embodiment of the present invention.
In FIG. 1, reference numeral 101 denotes an imaging lens that guides an optical image from a subject to the imaging element 107 to form an image and includes a diaphragm mechanism. Reference numeral 102 denotes a lens driving unit that performs focus lens control, aperture control, and the like on the imaging lens 101 based on control by the overall control / calculation unit 115.

  Reference numeral 103 denotes a mirror for guiding an optical image that has passed through the imaging lens 101 to a finder (not shown), and is generally called a quick return (QR) mirror. The QR mirror 103 guides the optical image to the viewfinder except during photographing, but operates to jump up and guide the optical image to the image sensor 107 during photographing. A mirror driving unit 104 drives the mirror 103 described above based on control by the overall control / calculation unit 115.

  Reference numeral 105 denotes a shutter having a shutter plane corresponding to a focal plane type front curtain / rear curtain used in a so-called single-lens reflex camera, and controls exposure time and light shielding of an optical image that has passed through the imaging lens 101. A shutter driving unit 106 drives the shutter described above based on control by the overall control / calculation unit 115.

  Focus control and exposure control are controlled by the lens driving unit 102 and the shutter driving unit 106 based on the output signals of the distance measuring unit 114 that measures the distance to the subject and the photometric unit 113 that measures the luminance of the subject. It is controlled by the calculation unit 115. However, this is a case of still image shooting, and in the case of moving image shooting, these distance measurement unit 114 and photometry unit 113 are not used, and distance measurement or photometry is performed based on the image signal of the image sensor 107. Control photometry.

  Reference numeral 107 denotes a (solid) image sensor for taking in an optical image of a subject formed by the imaging lens 101 as an image signal. The image sensor 107 of the present embodiment is formed by, for example, a CMOS sensor. Reference numeral 108 denotes various correction processes such as an amplification process of an image signal output from the image sensor 107, an A / D conversion process for performing analog-digital conversion, and a defect correction for image data after A / D conversion, or an image An imaging signal processing circuit unit that performs compression processing for compressing data. Reference numeral 109 denotes a timing generation circuit unit that outputs various timing signals to the image sensor 107 and the image signal processing circuit unit 108.

  Reference numeral 115 denotes an overall control / arithmetic unit that comprehensively controls various arithmetic processes and the entire imaging apparatus 100. Reference numeral 116 denotes a memory unit for temporarily storing image data and permanently storing various adjustment values and programs for executing various controls by the overall control / arithmetic unit 115.

  Reference numeral 110 denotes a recording medium control interface (I / F) unit for performing recording processing of image data and the like on the recording medium 111 or reading processing of image data and the like from the recording medium 111. Reference numeral 111 denotes a detachable recording medium including a semiconductor memory or the like for recording various data such as image data.

  Reference numeral 112 denotes an external interface (I / F) unit for communicating with an external device 200 such as a computer. Reference numeral 117 denotes a display unit that displays captured still images, moving images, and the like.

Next, the operation of the digital camera at the time of shooting will be described.
FIG. 2 is a flowchart showing a driving method of the digital camera (imaging device) 100 according to the embodiment of the present invention.

  In the digital camera 100, when a main power supply (not shown) is turned on, the power supply of each drive unit is turned on, and further, the power supply of the imaging system such as the imaging signal processing circuit unit 108 is turned on.

  Thereafter, when a release button (not shown) is pressed halfway (S101 / YES), the overall control / arithmetic unit 115 controls the timing generation circuit unit 109 and the imaging signal processing circuit unit 108 to capture a moving image. The image sensor 107 is initialized (S102). As a result, the image sensor 107 can store image signals.

  Subsequently, the overall control / arithmetic unit 115 raises the mirror 103 through the mirror driving unit 104 and opens the shutter 105 through the shutter driving unit 106 so that the image sensor 107 is exposed to light (S103). As a result, an optical image from the subject is formed on the image sensor 107.

  At the same time, the overall control / arithmetic unit 115 cannot control the exposure with the mechanical shutter 105 when the image sensor 107 is exposed to light. Therefore, while controlling the exposure amount with an electronic shutter (not shown), Is exposed (S104).

  Subsequently, the overall control / arithmetic unit 115 controls the timing generation circuit unit 109 and the imaging signal processing circuit unit 108 to read out an image signal from the imaging element 107 in order to read out the image signal ( S105). The readout in step S105 is so-called rolling readout in which the timing at which the image signal is read out is different between the upper part and the lower part of the imaging surface (pixel unit) of the imaging element 107.

  Subsequently, the overall control / arithmetic unit 115 causes the image signal processing circuit unit 108 to process the image signal for the moving image read from the image sensor 107, and converts the image signal for the moving image into the image signal for the moving image. Based on this, moving image data is generated. Then, the overall control / calculation unit 115 displays a moving image based on the moving image data generated by the image signal processing circuit unit 108 on the display unit 117 (S106).

  At the same time, the overall control / arithmetic unit 115 measures the subject brightness based on the image signal read from the image sensor 107 and controls an electronic shutter (not shown) to keep the exposure amount appropriate and to adjust the contrast of the subject. The lens drive unit 102 is driven to drive the imaging lens 101 so that the subject is always focused (focused) (S107). Then, the moving image is displayed on the display unit 117 by periodically executing steps S104 to S107.

  Subsequently, the overall control / arithmetic unit 115 determines whether or not a release button (not shown) is fully pressed (S108). If the release button is not fully pressed (S108 / NO), the step is again performed. Return to S104.

  Subsequently, when a release button (not shown) is fully pressed (S108 / YES), the shutter 105 is once closed and the mirror 104 is lowered (S109).

  Subsequently, the overall control / calculation unit 115 causes the photometry unit 113 to measure the subject brightness in order to adjust the exposure amount, and simultaneously causes the distance measurement unit 114 to measure the subject distance in order to adjust the focus. Then, the overall control / calculation unit 115 causes the lens driving unit 102 to perform the focusing operation of the imaging lens 101 in accordance with the distance measurement result of the subject distance, and images through the lens driving unit 102 based on the photometric value of the photometry unit 113. The diaphragm of the optical system of the lens 101 is controlled (S110).

  Subsequently, in order to capture a still image, the overall control / arithmetic unit 115 controls the timing generation circuit unit 109 and the imaging signal processing circuit unit 108 to initialize the imaging device 107 (S111). As a result, the image sensor 107 can store image signals.

  Subsequently, the overall control / arithmetic unit 115 raises the mirror 103 through the mirror driving unit 104 and controls the shutter 105 to open for a predetermined time through the shutter driving unit 106 based on the photometric value of the photometric unit 113. Exposure for still images is performed (S112). Then, after a predetermined time has elapsed, the overall control / calculation unit 115 performs control so that the shutter 105 is closed and the mirror 103 is lowered.

  Subsequently, the overall control / arithmetic unit 115 controls the timing generation circuit unit 109 and the imaging signal processing circuit unit 108 to read out the image signal for the still image from the imaging element 107 in order to read out the image signal ( S113).

  Subsequently, the overall control / arithmetic unit 115 causes the image signal processing circuit unit 108 to perform signal processing on the image signal for the still image read from the image sensor 107, and generates still image data. In the image signal processing circuit unit 108, when the still image data is generated, processing such as correction of defective pixels is performed using the defect correction data. The still image data generated by the signal processing by the image signal processing circuit unit 108 is temporarily stored in the memory unit 116 (S114).

  Subsequently, the overall control / arithmetic unit 115 records the still image data stored in the memory unit 116 on the recording medium 111 via the recording medium control I / F unit 110 (S115).

  A series of imaging sequences is completed by the processing from the above steps S101 to S115, and the processing returns to the original processing (S101).

Next, a detailed configuration inside the image sensor 107 will be described.
FIG. 3 is a diagram showing a detailed configuration inside the image sensor 107.

  In FIG. 3, reference numeral 201 denotes an aperture pixel unit that photoelectrically converts light incident from the imaging lens 101 (an optical image from a subject) to generate a signal charge and output the signal charge. In the aperture pixel unit 201, a plurality of pixels are arranged in a two-dimensional matrix. A vertical shift register 202 scans each pixel of the aperture pixel unit 201 in the vertical direction (y direction) and outputs an analog pixel signal from each pixel.

  203 transfers the analog pixel signal output from each pixel of the aperture pixel unit 201 in the vertical direction, performs processing such as SN processing and noise reduction, and outputs the image signal by scanning in the horizontal direction (x direction). This is an SN circuit / horizontal scanning unit 203. An output amplifier 204 amplifies the image signal output from the SN circuit / horizontal scanning unit 203 and outputs the image signal to the imaging signal processing circuit unit 108. In this manner, the image sensor 107 is an xy address scanning type image sensor.

  The electronic shutter value in moving image shooting in step S 107 is set by feeding back the calculation processing result by the overall control / calculation unit 115 based on the image signal read from the image sensor 107, and outputs this to the timing generation circuit unit 109. Is. The timing generation circuit unit 109 scans and reads out pixel signals generated in the aperture pixel unit 201 of the image sensor 107 in the vertical and horizontal directions based on the electronic shutter value given from the overall control / calculation unit 115. Is generated.

  FIG. 4 is a schematic diagram showing an outline of a first driving method showing timings of reading, monitor display, and lens driving of the image sensor (CMOS sensor) 107 in the digital camera (imaging device) 100 according to the embodiment of the present invention. is there. Here, in the readout by the image signal processing circuit unit 108 of the image signal of the image sensor (CMOS sensor) 107, each line segment having periods 41 and 42 indicates a readout period of each frame in the moving image.

  In the first driving method according to the present embodiment, in step S105, the imaging signal processing circuit unit 108 drives the imaging element (CMOS sensor) 107 in a rolling manner to read out an image signal (reading unit). The image signal (first signal) read for display on the monitor (display unit 117) in step S106 is subjected to signal processing by the image signal processing circuit unit 108 for each frame and is generated as image data (image data). Generating means) and displayed on the display unit 117. Further, the image signal (second signal) read out regarding the lens driving in step S107 is subjected to arithmetic processing by the overall control / arithmetic unit 115 for each frame, and imaged via the lens driving unit 102 in accordance with the arithmetic result. Driving control of the lens 101 is performed (imaging lens driving means).

  In the first driving method according to the present embodiment, the number of rows of the image signal read out from the image sensor (CMOS sensor) 107 by rolling is “the number of rows for image + the number of rows for dummy”, and the portion other than the image A dummy read period for reading out is provided.

  In other words, the image signal (first signal) read from the pixel area (partial pixel area) of some rows (image rows) in the aperture pixel unit 201 is displayed on the display unit 117. The moving image data is generated by the image signal processing circuit unit 108. The image signal from the pixel region in the image row is read during the period 41 in FIG. In addition, an image signal (second signal) read from a pixel area (dummy line) different from a part of the pixel area in the aperture pixel unit 201 is used for driving control of the imaging lens 101. Used for arithmetic processing. The image signal from the pixel area of the dummy row is read out during the period 42 in FIG. 4 at a timing different from the readout period 41 of the image signal from the pixel area of the image row. However, the image signal read during this period 42 is not used for image generation.

  As described above, one of the image signals read from the image sensor (CMOS sensor) 107 is subjected to signal processing by the image signal processing circuit unit 108 and becomes monitor display image data. As shown in FIG. 4, the same image data continues to be displayed on the display unit 117 until the next monitor display image data is produced. As described above, the image signal read from the image sensor (CMOS sensor) 107 is subjected to AF calculation (lens driving amount calculation) by the overall control / calculation unit 115, and the calculation result is obtained. Is used to control the drive of the imaging lens 101 based on the above.

  However, in the case of FIG. 4, the imaging lens 101 is not driven immediately after the AF calculation is completed. That is, the overall control / arithmetic unit 115 removes the period 41 during which the image signal of the pixel in the image row is read out, and removes the imaging signal of the pixel in the dummy row during the period 42 during which the imaging lens 101 is read out. Is controlled to drive (control means).

  If an operation that requires electric power such as driving of the imaging lens 101 is performed while an image signal is being read out from the image sensor (CMOS sensor) 107, the reference power supply of the output amplifier 204 fluctuates, and the fluctuations are It will ride on the signal as noise.

  In the first driving method according to the present embodiment, the imaging lens 101 is not driven during the readout period 41 of the image signal of the pixel in the image row, so that noise due to lens driving is prevented from riding on the image signal. be able to. However, since there is only a dummy signal readout period 42 during which the lens can be driven, the lens is driven only by an amount ending in that period. When further lens driving is required, the lens driving is performed in multiple steps. FIG. 4 shows the maximum time during which the lens can be driven.

  FIG. 5 is a schematic diagram showing an outline of a second driving method showing timings of reading, monitor display, and lens driving of the image sensor (CMOS sensor) 107 in the digital camera (imaging device) 100 according to the embodiment of the present invention. is there. Here, in the readout by the image signal processing circuit unit 108 of the image signal of the image sensor (CMOS sensor) 107, each line segment having periods 51 and 52 indicates a readout period of each frame in the moving image.

  In the second driving method in the present embodiment, in particular, a case where the amount of lens driving is larger than that in the first driving method described in FIG. 4 is shown.

  In the second driving method in the present embodiment, the number of rows of image signals read out from the image sensor (CMOS sensor) 107 by rolling is set to “number of rows for image + number of rows for dummy” as in FIG. Thus, a dummy readout period for reading out portions other than the image is provided.

  In other words, the image signal (first signal) read from the pixel area (partial pixel area) of some rows (image rows) in the aperture pixel unit 201 is displayed on the display unit 117. The moving image data is generated by the image signal processing circuit unit 108. The image signal from the pixel area of the image row is read out during the period 51 in FIG. In addition, an image signal (second signal) read from a pixel area (dummy line) different from a part of the pixel area in the aperture pixel unit 201 is used for driving control of the imaging lens 101. Used for arithmetic processing. The image signal from the pixel area of the dummy row is read out during the period 52 in FIG. 5 at a timing different from the readout period 51 of the image signal from the pixel area of the image row.

  However, in the second driving method, the period 51 for reading the image rows is made shorter than the period 41 in the first driving method by thinning out the number of image rows to be read. Also in the case of the second driving method, the overall control / arithmetic unit 115 reads out the imaging signals of the pixels in the dummy row after the period 51 in which the image signals of the pixels in the image row are read out. Control is performed so that the imaging lens 101 is driven during the closed period 52.

  In general, when displaying a moving image on a monitor (display unit 117), the time of one frame is kept unchanged, so when the period 51 for reading an image row is shortened, all the rest is used for a dummy. It can be used for the row readout period 52. Thereby, as shown in the lens drive of FIG. 5, the time which can drive a lens can be lengthened. FIG. 5 shows the maximum time during which the lens can be driven. The monitor display is the same as in the case of FIG.

  FIG. 6 is a schematic diagram showing an outline of a third driving method showing timings of reading, monitor display, and lens driving of the image sensor (CMOS sensor) 107 in the digital camera (imaging device) 100 according to the embodiment of the present invention. is there. Here, in the readout by the image signal processing circuit unit 108 of the image signal of the image sensor (CMOS sensor) 107, the line segments having the periods 61 and 62 and the line segments having the periods 63 and 64 are respectively in the moving image. A frame readout period is shown.

  In the third driving method in the present embodiment, in particular, a case where the amount of lens driving is larger than that in the second driving method described in FIG. 5 is shown.

  In the third driving method in the present embodiment, the number of rows of image signals read out from the image sensor (CMOS sensor) 107 by rolling is set to “number of rows for image + number of rows for dummy” as in FIG. Thus, a dummy readout period for reading out portions other than the image is provided. However, in the third driving method, an image row is read, but an image signal that is not used for monitor display or AF calculation is also read.

  That is, an image signal (first signal) read from a pixel region (partial pixel region) of a part of rows (image rows) in the aperture pixel unit 201 is displayed on the display unit 117 in the period 61. This is used for moving image data generated by the image signal processing circuit unit 108 for display, and is not used for monitor display or AF calculation in the period 63. In addition, an image signal (second signal) read from a pixel region in a row (dummy row) different from a part of the pixel regions in the aperture pixel portion 201 is driven in the period 62 by the imaging lens 101. Used for arithmetic processing for control.

  In FIG. 6, the image signal of the first frame in the period 61 and the period 62 is read out and used for both the monitor display and the AF calculation. On the other hand, the image signals of the second frame in the periods 63 and 64 are read out, but are not used for monitor display, and the display image displayed on the monitor (display unit 117) is the previous frame (first frame). Leave the frame. The second frame is not used for AF calculation. Instead, during the readout periods 63 and 64 of the second frame, the lens is driven for a longer time than the time of the second driving method shown in FIG. 5 by driving the imaging lens 101. it can. FIG. 6 shows the maximum time during which the lens can be driven.

That is, in the third driving method, the overall control / calculation unit 115 performs the following control.
In the period 61 during which the image signal processing circuit unit 108 reads out the first signal for generating image data, the lens driving unit 102 performs control so that the imaging lens 101 is not driven. On the other hand, in the image signal processing circuit unit 108, the lens driving unit 102 drives the imaging lens 101 during the first signal readout period 63 and the second signal readout periods 62 and 64 that are not used for generating image data. Take control.

  FIG. 7 is a schematic diagram showing an outline of a fourth driving method showing timings of reading, monitor display, and lens driving of the image sensor (CMOS sensor) 107 in the digital camera (imaging device) 100 according to the embodiment of the present invention. is there. Here, in the readout by the image signal processing circuit unit 108 of the image signal of the image sensor (CMOS sensor) 107, each line segment having periods 71 and 72 indicates a readout period of each frame in the moving image.

  In the fourth driving method in the present embodiment, the number of rows of image signals read out from the image sensor (CMOS sensor) 107 by rolling is set to “number of rows for image + number of rows for dummy” as in FIG. Thus, a dummy readout period for reading out portions other than the image is provided.

  In other words, the image signal (first signal) read from the pixel area (partial pixel area) of some rows (image rows) in the aperture pixel unit 201 is displayed on the display unit 117. The moving image data is generated by the image signal processing circuit unit 108. The image signal from the pixel area of this image row is read during the period 71 in FIG. In addition, an image signal (second signal) read from a pixel area (dummy line) different from a part of the pixel area in the aperture pixel unit 201 is used for driving control of the imaging lens 101. Used for arithmetic processing. The image signal from the pixel area of the dummy row is read out during the period 72 in FIG. 7 at a timing different from the readout period 71 of the image signal from the pixel area of the image row.

  In the fourth driving method in the present embodiment, the case where the sensor sensitivity of the image sensor (CMOS sensor) 107 at the time of shooting is particularly low is considered. When the sensor sensitivity is high, the low image signal is originally amplified and it becomes easy to see the noise due to lens driving.However, when the sensor sensitivity is low, it is not necessary to amplify the image signal so much that the noise due to the lens driving is reduced. Even if the level does not change, it becomes difficult to see in the image.

  In the fourth driving method in the present embodiment, considering that the noise becomes difficult to see, the readout of the image signal → AF calculation is completed without considering the readout period of the image signal for generating the image data. Subsequently, the imaging lens 101 is driven. FIG. 7 shows the maximum driveable time. Further, the time for one frame is not changed, and the monitor display is the same as in the case of FIG.

  In the above description, the image signal (first signal) read from the pixel region of the image row has been described as being used for monitor display. Any processing circuit unit 108 may be used as long as it is used for generating image data. Thereby, for example, even if it is not used for monitor display, it is also possible to store the generated image data in an external storage device and use it as a moving image.

  Each unit of FIG. 1 constituting the digital camera (imaging device) according to the present embodiment described above and each step of FIG. 2 showing the driving method of the digital camera are executed by a program stored in a RAM or ROM of a computer. It can be realized by operating. This program and a computer-readable storage medium storing the program are included in the present invention.

  Specifically, the program is recorded in a storage medium such as a CD-ROM, or provided to a computer via various transmission media. As a storage medium for recording the program, a flexible disk, a hard disk, a magnetic tape, a magneto-optical disk, a nonvolatile memory card, and the like can be used in addition to the CD-ROM. On the other hand, as the transmission medium of the program, a communication medium in a computer network (LAN, WAN such as the Internet, wireless communication network, etc.) system for propagating and supplying program information as a carrier wave can be used. Moreover, examples of the communication medium at this time include a wired line such as an optical fiber, a wireless line, and the like.

  In addition, the functions of the digital camera (imaging device) according to the present embodiment are realized by executing a program supplied by the computer, and an OS (operating system) or other program running on the computer. When the functions of the digital camera (imaging device) according to the present embodiment are realized in cooperation with the application software, etc., or all or part of the processing of the supplied program is a function expansion board or function expansion unit of a computer This program is also included in the present invention even when the function of the digital camera (imaging device) according to the present embodiment is realized.

1 is a block diagram illustrating a schematic configuration of a digital camera (imaging device) according to an embodiment of the present invention. 3 is a flowchart illustrating a method for driving a digital camera (imaging device) according to an embodiment of the present invention. It is a figure which shows the detailed structure inside an image pick-up element. It is a schematic diagram which shows the outline of the 1st drive method which shows each timing of the reading of the image pick-up element (CMOS sensor) in the digital camera (image pick-up device) of this embodiment, a monitor display, and a lens drive. It is a schematic diagram which shows the outline of the 2nd drive method which shows each timing of the reading of the image pick-up element (CMOS sensor) in the digital camera (image pick-up device) of this embodiment, a monitor display, and a lens drive. It is a schematic diagram which shows the outline of the 3rd drive method which shows each timing of the reading of the image pick-up element (CMOS sensor), monitor display, and lens drive in the digital camera (image pick-up device) of embodiment of this invention. It is a schematic diagram which shows the outline of the 4th drive method which shows each timing of the reading of the image pick-up element (CMOS sensor), the monitor display, and lens drive in the digital camera (image pick-up device) of embodiment of this invention. It is a schematic diagram which shows the outline of each timing of the reading of a CMOS sensor, a monitor display, and a lens drive in a general imaging device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Imaging lens 102 Lens drive part 103 Mirror 104 Mirror drive part 105 Shutter 106 Shutter drive part 107 Image pick-up element 108 Imaging signal processing circuit part 109 Timing generation circuit part 110 Recording medium control I / F part 111 Recording medium 112 External I / F part 113 Photometry unit 114 Distance measurement unit 115 Overall control / calculation unit 116 Memory unit 117 Display unit 200 External device

Claims (4)

An imaging device having a pixel portion in which pixels are arranged in a two-dimensional matrix;
An imaging lens provided to guide an optical image from a subject to the imaging device;
Reading means for reading the first signal from a part of the pixel area of the pixel portion and reading the second signal from a pixel area different from the part of the pixel area at a timing different from the first signal. When,
Image data generating means for generating image data based on the first signal;
Imaging lens driving means for driving the imaging lens based on the second signal;
An image pickup apparatus comprising: a control unit configured to control to drive the imaging lens by the imaging lens driving unit during a period in which the reading unit is reading the second signal.   The imaging apparatus according to claim 1, wherein when the first signal is read, the reading unit performs reading by thinning out pixels in the partial pixel region.   The control means drives the imaging lens by the imaging lens driving means during a period in which the readout means reads out the first signal that is not used for generating the image data out of the first signal. The imaging apparatus according to claim 1, wherein the imaging apparatus is controlled. An imaging device driving method comprising: an imaging device having a pixel portion in which pixels are arranged in a two-dimensional matrix; and an imaging lens provided to guide an optical image from a subject to the imaging device,
A reading step of reading the first signal from a part of the pixel area in the pixel portion and reading the second signal from a pixel area different from the part of the pixel area at a timing different from the first signal. When,
An image data generation step for generating image data based on the first signal;
An imaging lens driving step for driving the imaging lens based on the second signal;
And a control step of performing control to drive the imaging lens by the imaging lens driving step during a period in which the second signal is read in the reading step.

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