JP2004289636A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera capable of realizing a moving picture display function even in the case of employing an imaging element with a greater number of pixels and performing reduction of the photographing interval and power saving. <P>SOLUTION: In the case of photographing and recording a still picture, image signals of all pixels are read from a CCD 16, a plurality of processors 40 share the processing of photographing signals of one image and carry out parallel processing (shared processing), and in the case of displaying a moving picture, one processor 40 (concretely, a first processor 40A) performs the thinned reading and the photographing signal processing, and a reduced image of the substantial image obtained by the photographing of the CCD 16 is displayed as a moving picture of a through-image. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital camera, and more particularly, to a digital camera that captures a subject with an imaging device and acquires image data representing the subject image.
[0002]
[Prior art]
In recent years, with the increase in the resolution of imaging devices such as CCD (Charge Coupled Device) and CMOS (Complementary Metal-Oxide Semiconductor) image sensors, the number of pixels of digital cameras has increased, and those that exceed 10 million pixels have been developed. It is becoming. In a digital camera, when the number of pixels of an image increases, the amount of data processing per shooting increases, and the shooting interval (waiting time until the next shooting becomes possible) becomes longer.
[0003]
As a technique for this, there is a technique in which a plurality of storage means for recording digital image data (hereinafter referred to as image data) obtained by photographing is provided in a digital camera, and image data is recorded in parallel in a plurality of storage means (patent) Reference 1). However, this technique is for speeding up the image data recording process, and speeds up the imaging signal processing such as defective pixel correction, edge enhancement processing, and YC conversion processing applied to the image data before the recording processing. There was a limit to shortening the shooting interval. For this reason, in recent years, digital cameras have been developed that divide image data for one image obtained by one shooting and share (shoot in parallel) shooting signal processing for one image with a plurality of processors. ing. In this case, since the power consumption increases by the number of processors, it is necessary to minimize the power consumption other than the main shooting for shooting a still image.
[0004]
Digital cameras are generally provided with display means for displaying captured images, such as a liquid crystal monitor. This display means displays a moving image of the subject image captured by the digital camera at the time of shooting, and is used as a viewfinder (so-called viewfinder) for the photographer to adjust the angle of view and focus. If an image sensor is used, the frame rate will be low. Specifically, in the case of an image sensor that exceeds 10 million pixels, an image can be read only at a speed of about 1 frame / second, and a moving image display function that requires a frame rate of about 30 frames / second is achieved. I couldn't. For this reason, focusing on the fact that moving images are not as demanding as resolution for still images, the reading speed is improved by thinning out images from the image sensor in a predetermined direction when displaying moving images. The technique to do is proposed (refer patent document 2).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-23365
[Patent Document 2]
JP-A-5-91415
[0006]
[Problems to be solved by the invention]
However, if the conventional technique for thinning out and reading out images is simply applied to a digital camera that shares shooting signal processing with a plurality of processors in order to shorten the shooting interval, a moving image is one image (one frame) than a still image. ), The number of processors is the same as that of still images, but the number of pixels is reduced, so that power is wasted.
[0007]
The present invention has been made to solve the above problems, and can provide a moving image display function even when the number of pixels is increased, and can provide a moving image display function capable of shortening a shooting interval and saving power. The purpose is to provide.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 receives light corresponding to a subject image, accumulates charges corresponding to the amount of received light for each pixel, and generates and accumulates an image signal. An image pickup device having sweeping means for sweeping out electric charges, a read out means for reading out the image signal from the image pickup element, and performing predetermined photographing signal processing on image data based on the image signal read out by the read out means A plurality of shooting signal processing means for sharing and processing the shooting signal processing for one subject image; and a recording means for recording the image data processed in parallel by the plurality of shooting signal processing means on a recording medium; And a display unit for displaying the subject image, wherein when the subject image is displayed as a moving image on the display unit, the reading unit includes the sweep unit. The image signal is thinned out and read out from the image sensor at a predetermined cycle, and only one of the plurality of image signal processing means is in charge of the image signal processing for the image data of the read result. It is said.
[0009]
According to the first aspect of the present invention, the image sensor receives light corresponding to the subject image, accumulates charges corresponding to the amount of received light for each pixel, and reads the accumulated charges for each pixel as an image signal. By reading by the means, image data representing the subject image is acquired.
The imaging signal processing of the image data representing the subject image is shared by a plurality of imaging signal processing means and processed in parallel. The parallel processed image data is recorded on the recording medium by the recording means, and the recorded image data can be reproduced and displayed on the display means later. That is, since the plurality of shooting signal processing means share the shooting signal processing of the image data representing the subject image and perform parallel processing, the shooting interval can be shortened. The recording medium may be built in the digital camera or may be detachably loaded in the digital camera.
[0010]
Here, when the subject image is displayed as a moving image on the display means, the reading means operates the image pickup element sweeping means to sweep out the accumulated charges at a predetermined period when the image signal is read from the image pickup element. The image signal is read out from the image sensor while being thinned out at a predetermined cycle. As a result, it is possible to acquire image data obtained by reducing the original subject image, and only one of the plurality of imaging signal processing means is in charge of the imaging signal processing of the image data. That is, by thinning out and reading out image signals from the image sensor, high-speed readout becomes possible, a moving image shooting function can be realized, and shooting signal processing is performed by only one shooting signal processing means, and other shooting signal processing means are driven. Therefore, power saving can be realized.
[0011]
According to a second aspect of the present invention, there is provided a sweeping unit that receives light corresponding to a subject image, accumulates charges corresponding to the amount of received light for each pixel, generates an image signal, and sweeps the accumulated charges. An image pickup device, a reading unit for reading out the image signal from the image pickup device, and performing predetermined shooting signal processing on image data based on the image signal read out by the reading unit and performing the shooting for one subject image A plurality of photographing signal processing means for sharing signal processing in parallel; a recording means for recording the image data processed in parallel by the plurality of photographing signal processing means on a recording medium; and for displaying the subject image And when the subject image is displayed as a moving image on the display means, the reading means operates the sweeping means to Reads the image signal of the partial region of the object image, only any one of the imaging signal processing the plurality of imaging signal processing unit for the image data of the read result is in charge, is characterized by.
[0012]
According to the second aspect of the present invention, the image sensor receives light corresponding to the subject image, accumulates charges corresponding to the received light amount for each pixel, and reads the accumulated charges for each pixel as an image signal. By reading by the means, image data representing the subject image is acquired.
The imaging signal processing of the image data representing the subject image is shared by a plurality of imaging signal processing means and processed in parallel. The parallel processed image data is recorded on a recording medium by the recording means, and the recorded image data can be reproduced and displayed on the display means later. That is, since the plurality of shooting signal processing means share the shooting signal processing of the image data representing the subject image and perform parallel processing, the shooting interval can be shortened. The recording medium may be built in the digital camera or may be detachably loaded in the digital camera.
[0013]
Here, when the subject image is displayed as a moving image on the display means, the reading means operates the image pickup element sweeping means to sweep out the accumulated charge in the unnecessary area when reading the image signal from the image pickup element. An image signal of a partial region of the subject image is read from the image sensor.
Thereby, image data representing a partial region of the original subject image can be acquired. Only one of the plurality of imaging signal processing means is in charge of the imaging signal processing of the image data. That is, by reading out only a part of the subject image from the image sensor, high-speed readout is possible, a moving image shooting function can be realized, and shooting signal processing is performed by only one shooting signal processing means, and other shootings are performed. Since the signal processing means is not driven, power saving can be realized. In this case, as described in claim 3, a part of the subject image may be an image region used for focusing the subject image.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, an example of an embodiment according to the present invention will be described in detail with reference to the drawings.
[0015]
[overall structure]
As shown in FIG. 1, a digital camera 10 according to the present embodiment includes an optical unit 12 configured to include a lens for forming a subject image, and a drive circuit 14 for driving the optical unit 12. A CCD image sensor (hereinafter simply referred to as a CCD) 16 that is disposed behind the optical axis of the optical unit 12 and shoots a subject image at the 10 million pixel level, and controls the drive of the CCD 16 and is read from the CCD 16. An analog front end 18 that performs predetermined analog signal processing on an output signal indicating a subject image, a digital arithmetic processing unit 20 that mainly performs predetermined digital signal processing on image data, and recording means As a media interface (I / F) 24 for controlling reading / writing of various data with respect to the media 22 and display means, Image data is output to an external device such as a PC connected via a predetermined cable, a display monitor 26 for displaying an image obtained by the shadow and various information, an operation means 28 operated by a photographer, and a predetermined cable. And an external output I / F 30.
[0016]
Although not shown in the drawing, the operation means 28 is a release button that is operated when instructing to record and record a still image, a mode changeover switch that is operated to select one of the shooting mode / playback mode, A cursor button that is operated to set various parameters or specify an image to be reproduced when the reproduction mode is selected, a power switch that is operated to turn on / off the power of the digital camera 10, and the like are included.
[0017]
The optical unit 12 is a zoom lens (focal length variable lens) having a mechanism (autofocus (AF) mechanism) capable of changing a focal position by a driving force of a driving source such as a stepping motor. The AF mechanism and the zoom mechanism Is driven by the drive circuit 14. A focal length fixed lens having only an AF mechanism may be used.
[0018]
In the present embodiment, as the focus control, a so-called TTL (Through The Lens) system that adjusts the lens position so that the contrast of an image obtained by shooting is maximized is adopted, and the focus is controlled within the shooting area. In-focus control is automatically performed so that a subject existing at a predetermined position (AF frame) is in focus. Specifically, when the photographing mode is selected by the operation of the mode change switch of the operation means 28 by the photographer, the focus control is automatically performed by pressing the release button halfway.
[0019]
A CCD 16 that is an image sensor is disposed at a position corresponding to the focal position of the optical unit 12. The light passing through the optical unit 12 is imaged on the light receiving surface of the CCD 16.
[0020]
A large number of photoelectric conversion cells are arranged in a matrix on the light receiving surface of the CCD 16, and signal charges corresponding to the amount of received light are accumulated in each cell, and the accumulated signals are output as analog image signals. . Specifically, in the present embodiment, an interline CCD sensor having a so-called electronic shutter function is used as the CCD 16. In the present invention, the type of the CCD 16 is not particularly limited. Further, a CMOS image sensor can be used instead of the CCD 16.
[0021]
The CCD 16 is connected to an analog front end 18, and the analog front end 18 includes a timing generator (TG) 32, an analog processing circuit 34, and an A / D converter (A / D) 36. Has been.
[0022]
The timing generator 32 mainly generates timing signals (details will be described later) for driving the CCD 16, the analog processing circuit 34, and the A / D converter 36, and supplies them to each unit. The timing generator 32 may be provided separately from the analog front end 18 or may be built in the CCD 16.
[0023]
The CCD 16 synchronizes with the timing signal from the timing generator 32 to provide an analog image signal representing a photographed subject image (a signal representing the amount of light received at each of a number of photoelectric conversion cells arranged in a matrix on the light receiving surface. ) Is output.
That is, the timing generator 32 corresponds to the reading means of the present invention. The analog image signal output from the CCD 16 is input to the analog front end 18.
[0024]
In the analog front end 18, the input analog image signal is subjected to correlated double sampling processing by the analog processing circuit 34 in synchronization with the timing signal of the timing generator 32, and sensitivity adjustment for each color of RGB is performed. After that, it is converted into a digital image signal by the A / D converter 36 and output. The output end of the analog front end 18 is connected to the digital arithmetic processing unit 20, and the digital image signal output from the analog front end 18 is transmitted to the digital arithmetic processing unit 20.
[0025]
The digital arithmetic processing unit 20 includes a plurality of processors 40 as photographing signal processing means, and for each processor 40, an SDRAM 42 for temporarily storing image data obtained mainly by photographing by the CCD 16, and various types of processors 40 A ROM 44 in which programs, parameters, and the like are stored in advance is provided. Each processor 40 is connected to a corresponding SDRAM 42 and ROM 44 via a bus 46, and can arbitrarily access the SDRAM 42 and ROM 44.
[0026]
In the present embodiment, as an example, a case where the first to third three processors 40 are provided will be described. In the following, when each processor is distinguished, it is referred to as a first processor 40A, a second processor 40B, and a third processor 40C, and the SDRAM 42, the ROM 44, and the bus 46 also indicate alphabets (A / B / C) is given at the end of the code for explanation.
[0027]
Each processor 40 is connected to the analog front end 18 and the media I / F 24 so as to exchange various information. Each processor 40 can capture a digital image signal output from the analog front end 18 to the digital arithmetic processing unit 20. Each processor 40 temporarily stores the captured digital image signal as image data in a predetermined area of the corresponding SDRAM 42, then reads the image data from the SDRAM 42, performs predetermined digital signal processing, and then supports each of them. Write back to SDRAM 42.
[0028]
The digital signal processing executed by the processor 40 at this time includes, for example, defective pixel correction processing for correcting image data corresponding to defective pixels of the CCD 16 using image data corresponding to pixels around the defective pixels, Γ correction processing for correcting brightness, edge enhancement processing for sharpening an image, gain correction processing for adjusting color balance (so-called white balance correction processing), and R (red), G (green), B ( The image data of the three primary colors (blue) is converted to a Y signal (luminance signal) and a C signal (color difference signal), and the data written back to the SDRAM 42 is data after the YC conversion processing (YC signal). It is.
[0029]
The image data written back to the SDRAM 42 is read out by the corresponding processor 40 when the user instructs to record and record, and in a predetermined compression format (for example, JPEG (Joint Photographic Groups Group) format). After the compression processing is performed, the data is recorded on the same recording medium 22 via the medium I / F 24. As the recording medium 22, various forms such as a micro drive, a smart media, a PC cart, a micro drive, a multimedia card (MMC), a magnetic disk, an optical disk, a magneto-optical disk, and a memory stick are possible and used. The signal processing means and interface corresponding to the media to be used are applied.
[0030]
Hereinafter, processing (digital signal processing and compression processing) executed on the image data in the processor 40 will be collectively referred to as imaging signal processing.
[0031]
Here, in the digital camera 10 according to the present embodiment, as shown in FIG. 2, one image (one frame) 50 obtained by one photographing is divided into three regions (in order to speed up photographing signal processing). The assigned area 52 is divided, and the first to third processors 40A to 40C share the imaging signal processing to perform parallel processing. That is, the imaging signal processing for 50 images per image is divided by the first to third processors. FIG. 2 shows a case where one image 50 is composed of 3α lines (α: a positive integer), and shows a case where the image is equally divided into three for each α line in the line direction. In FIG. 2, alphabets (A / B / C) representing the processors 40 </ b> A to 40 </ b> C in charge are assigned to the end of the code of the assigned region 52.
[0032]
For this division processing, each processor 40 is supplied with the timing signal generated by the timing generator 32 from the analog front end 18 in addition to the image data.
[0033]
Specifically, in the analog front end 18 described above, the analog signal processing and A / D conversion are performed on the signal output in synchronization with the timing signal of the timing generator 32, so that the digital image signal is also output to the timing generator. The signal is output from the analog front end 18 in synchronization with the 32 timing signals. By supplying the timing signal of the timing generator 32 to each processor 40, each processor 40 can grasp the position of the digital image signal output from the analog front end 18 on the image by this timing signal. As shown in the figure, image data of an area (hereinafter referred to as a capture area) 54 necessary for the imaging signal processing of each responsible area 52 is captured, and the imaging signal processing of the responsible area 52 is performed. In FIG. 2, alphabets (A / B / C) representing the processors 40 </ b> A to 40 </ b> C in charge are attached to the end of the code of the capture area 54.
[0034]
As for the capture area 54, in consideration of interpolation processing using a plurality of peripheral pixels included in the imaging signal processing, as shown in FIG. 2, the image is divided between the processors 40 adjacent to the assigned area 52. The overlapping area 56 is provided and set so that the vicinity of the joint L between the areas in charge of both positions overlaps, and the first to third processors 40 divide the image data while providing the overlapping area 56 with each other. It is good to take in.
[0035]
Each of the first to third processors 40 </ b> A to 40 </ b> C is connected to the bus 48 as shown in FIG. 1 and can communicate with each other via the bus 48. The first to third processors 40 </ b> A to 40 </ b> C can transmit and receive the image data processed by the communication via the bus 48 and can also grasp each other's situation.
[0036]
At least one of the first to third processors 40A to 40C, specifically the first processor 40A in this embodiment, is connected to the display monitor 26 and the external output I / F 30. Under the control of the first processor 40A, the captured image can be displayed on the display monitor 26, or image data obtained by imaging can be output from the external output I / F 30 to the external device. The designation of the image data to be output to the external device is input from the external device via the external output I / F 30.
[0037]
The display monitor 26 is configured to display a moving image (through image) obtained by continuous imaging by the CCD 16 and to be used as a finder when the shooting mode is selected. The captured image is displayed by outputting it to the display monitor 26 via a display control circuit (not shown) for converting the image data after YC conversion by the processor 40 into a video signal of a predetermined method (for example, NTSC method). Done.
[0038]
In addition, any one of the first to third processors 40A to 40C, specifically the first processor 40A in the present embodiment, performs the entire operation of the digital camera 10 including the processing of the other processors 40. Used as a master processor for controlling.
[0039]
For this reason, the first processor 40A as the master processor is also connected to the drive circuit 14, the timing generator 32, and the operation means 28. The first processor 40A can control the operation of the entire digital camera 10 by controlling the operation of the drive circuit 14, the timing generator 32, and each processor 40 in accordance with the operation of the operation means 28. .
[0040]
In the digital camera 10 according to the present embodiment, a thinned image is used for moving image (through image) display. That is, the entire image 50 obtained by the CCD 16 is used for shooting and recording a still image, but a reduced image thinned out at a predetermined rate is used for moving image display. For this purpose, a CCD image sensor provided with a sweeping means for sweeping signal charges as shown in FIG. 3 is used as the CCD 16. FIG. 3 shows an example in which a general interline transfer type CCD image sensor is provided with sweeping means for sweeping signal charges in units of rows.
[0041]
As shown in FIG. 3, in the interline transfer type CCD 16, photoelectric conversion cells 70 that generate charges corresponding to incident light are arranged at a predetermined pitch in the horizontal and vertical directions. In the figure, “R”, “G”, and “B” written for each photoelectric conversion cell 70 are color separation filters (not shown) provided on the light receiving surface of the corresponding photoelectric conversion cell 70. Corresponding colors are indicated, “R” indicates red, “G” indicates green, and “B” indicates blue. Further, in the CCD 16, vertical transfer paths 74 are formed between the light receiving unit rows corresponding to the respective light receiving unit rows. The vertical transfer path 74 includes a vertical transfer CCD having a vertical transfer electrode V provided corresponding to each of the photoelectric conversion cells 70.
[0042]
In addition, a predetermined level of voltage is applied to the vertical transfer electrode V that is electrically connected to the CCD 16, so that the signal charge generated in the photoelectric conversion cell 70 is transferred from the photoelectric conversion cell 70 to the corresponding vertical transfer CCD. Transfer gates (transfer gates) 76 to be transferred to each photoelectric conversion cell 70 are provided.
[0043]
Here, the vertical transfer electrodes V are electrically connected to each row. Further, the vertical drive signal wiring 78 is supplied to the CCD 16 so that every seventh vertical drive signal is supplied to the vertical transfer electrode V along the charge transfer direction (vertical direction) by the vertical transfer path 74. Is provided. That is, the CCD 16 is configured to drive the vertical transfer path 74 with eight-phase vertical drive signals φV1 to φV8. The vertical drive signals φV1, φV2,. Applied to V2,..., V8.
[0044]
Further, a horizontal transfer path 82 for transferring charges transferred from each vertical transfer path 74 in the horizontal direction is formed in the CCD 16 adjacent to the vertical transfer CCD located at the most downstream side in the charge transfer direction of each vertical transfer path 74. Has been. The horizontal transfer path 82 includes a horizontal transfer CCD having a horizontal transfer electrode H provided corresponding to each of the corresponding vertical transfer paths 74. The horizontal transfer electrodes H are configured so that horizontal drive signals are supplied every two along the charge transfer direction of the horizontal transfer path 82. That is, the CCD 16 is configured to drive the horizontal transfer path 82 by two-phase horizontal drive signals φH1 and φH2, and in the horizontal transfer path 82, the horizontal drive signals φH1 and φH2 are applied to the horizontal transfer electrodes H1L and H2L, respectively. Is done. In the CCD 16, the charges transferred from the vertical transfer path are transferred in a predetermined direction in synchronization with the horizontal drive signal in the horizontal transfer path 82, and output as an image signal from the end in the predetermined direction. The above is the configuration of a general interline transfer type CCD image sensor.
[0045]
The CCD 16 shown in FIG. 3 applies a predetermined level of voltage as the reset signal φR to the general interline transfer type CCD image sensor as described above, whereby the horizontal transfer included in the horizontal transfer path 82 is performed. A horizontal reset drain 88 for sweeping out charges accumulated in the CCD is further provided. That is, the signal charge of the unnecessary portion is transferred from the vertical transfer path 74 to the horizontal transfer path 82 and is accumulated in the horizontal transfer CCD, and then the reset signal φR, that is, a predetermined level voltage is applied to the horizontal reset drain 88. And can be swept out line by line.
[0046]
The vertical drive signals φV1 to φV8, the horizontal drive signals φH1 and φH2, and the reset signal φR, which are timing signals for driving the CCD 16, are supplied from the timing generator 32.
[0047]
In this embodiment, for the sake of simplicity of explanation, a case will be described in which the CCD 16 is configured to sweep signal charges in units of rows (see FIG. 3). However, the CCD 16 sweeps out signal charges in units of columns. The signal charge may be swept out in both row and column units.
[0048]
Next, the operation of the present embodiment will be described.
[0049]
The digital camera 10 according to the present embodiment is activated when the power is turned on by the operation of the power switch of the operation unit 28 by the photographer. When shooting with the digital camera 10, the photographer operates the mode switch of the operation means 28 to select the shooting mode. When the photographing mode is selected by the photographer, the digital camera 10 operates as shown in FIG.
[0050]
That is, when the photographing mode is selected, the digital camera 10 first drives the timing generator 32 under the control of the first processor 40A as the master processor in step 100 of FIG. In the next step 102, the analog image signal is thinned out and read out from the CCD 16 for each shooting.
[0051]
Specifically, when an optical image of a subject is formed on the surface of the CCD 16 on the photoelectric conversion cell 70 side by the optical unit 12, photoelectric conversion is performed in each photoelectric conversion cell 70, and a signal charge is generated according to light intensity and time. Accumulated. This creates a charge image.
[0052]
Here, when the vertical drive signals φV1 to φV8 are set to a predetermined level voltage and the corresponding transfer gates 76 are turned on, the signal charges accumulated by all the photoelectric conversion cells 70 are simultaneously applied to the corresponding vertical transfer CCDs. Transferred. The signal charges read out to the vertical transfer CCD are sequentially transferred to the horizontal transfer path side in synchronization with the vertical drive signal applied to the vertical transfer electrode V of each vertical transfer CCD. With the above operation, the signal charges for each row are transferred to the horizontal transfer CCD corresponding to the vertical transfer path 74 of the horizontal transfer path 82 one after another.
[0053]
When the signal charges of the row in the horizontal transfer path 82 are transferred, the horizontal drive signals φH1 and φH2 are supplied to the horizontal transfer electrode H of the horizontal transfer path 82, and the transferred signal of the row is transferred. Outputs charge. When the signal charge of another row is transferred to the horizontal transfer path 82, the supply of the horizontal drive signals φH1 and φH2 to the horizontal transfer electrode H of the horizontal transfer path 82 is stopped, and the horizontal reset drain 88 By applying a voltage of a predetermined level to the signal line, the transferred signal charges of the row are swept out.
[0054]
By repeating the output and sweeping of the signal charges in units of rows in a predetermined cycle, for example, when one row of signal charges is output, the image signals are read out from the CCD 16 in the vertical direction. Compared with reading out all image signals, the readout time can be greatly reduced. Further, by this thinning readout, an analog image signal representing an image reduced in the vertical direction is input to the analog front end 18. The analog front end 18 performs predetermined analog signal processing such as correlated double sampling processing and sensitivity adjustment for each RGB color on the input analog image signal, and then performs A / D conversion to output a digital image signal. To do.
[0055]
In the next step 104, the digital image signal output from the analog front end 18 is taken in as image data by the first processor 40A, and photographing signal processing is performed.
[0056]
In the present embodiment, the CCD 16 is provided with sweeping means for sweeping signal charges in units of rows, and thinning is performed only in the vertical direction when reading from the CCD 16, so that the image signal output from the analog front end 18 is output. The represented image is different from the aspect ratio of the original image. For this reason, the first processor 40A may perform digital image processing for thinning out the captured image data in the horizontal direction.
When the CCD 16 is configured so that signal charges can be swept out in both row and column units, the image signal may be read out from the CCD 16 in both vertical and horizontal directions.
[0057]
Alternatively, the digital image signal may be thinned out for each predetermined pixel by the first processor 40A, and the thinning in the horizontal direction may be performed along with the capture of the image data. Note that this thinning-in can be easily performed by using the timing signal of the timing generator 32. Specifically, in the analog front end 18 described above, the analog signal processing and A / D conversion are performed on the signal output in synchronization with the timing signal of the timing generator 32, so that the digital image signal is also output to the timing generator. The signal is output from the analog front end 18 in synchronization with the 32 timing signals. Since the timing signal of the timing generator 32 is also supplied to each processor 40, the first processor 40A grasps the position of the digital image signal output from the analog front end 18 on the image by this timing signal. In addition, a digital image signal corresponding to a necessary pixel can be selected and captured.
[0058]
In the next step 106, the first processor 40A outputs the image data after the photographing signal processing to the display monitor 26 via a display control circuit (not shown), thereby displaying a moving image (through image display). . As a result, when an image obtained by continuous shooting by the CCD 16 is displayed as a moving image, a reduced image obtained by reducing the original image by reading out the image signal from the CCD 16 and displaying it as a moving image is displayed. Thereafter, the process returns from the next step 108 to step 102 until the shooting / recording instruction is input, and the subject image captured by the digital camera 10 is displayed as a moving image as a through image in substantially real time.
[0059]
The photographer adjusts the shooting angle of view while confirming the subject image from the through image displayed on the display monitor 26, and operates the release switch of the operation means 28. Specifically, the release switch is pressed halfway to cause the digital camera 10 to perform focus control (drive the drive circuit 14 under the control of the first processor 40A and move the focus lens to a position where the contrast becomes maximum), and then Press the release button all the way down to enter a still image shooting / recording instruction.
[0060]
In the digital camera 10, when a shooting / recording instruction is input by operating the release switch of the operation means 28, the process proceeds from step 108 to step 110. In step 110, the timing generator 32 is driven by the control of the first processor 40, and the image signals of all the pixels representing the image taken from the CCD 16 are read out. That is, during still image shooting and recording, the signal charges of all rows are sequentially output from the CCD 16 without driving the horizontal reset drain 88.
[0061]
Thus, in synchronization with the timing signal of the timing generator 32, analog image signals representing photographed subject images are sequentially output from the CCD 16 and input to the analog front end 18. Then, the analog front end 18 subjects the analog image signal input from the CCD 16 to predetermined analog signal processing such as correlated double sampling processing and sensitivity adjustment for each RGB color, and then A / D conversion is performed. A digital image signal is output.
[0062]
In the next step 112, the digital image signals for one image output from the analog front end 18 are divided by the first to third processors 40A to 40C while providing the overlapping areas 56 as shown in FIG. The captured signal processing is performed for each of the assigned areas 52A to 52C. In the first to third processors 40A to 40C, by using the timing signal from the timing generator 32, the digital image signal of each capture area 54 can be selected and captured. Split capture can be performed.
[0063]
In the next step 114, the process waits until the photographing signal processing in all the processors 40 is completed. In this embodiment, the end of the photographing signal processing is determined by each processor 40 notifying each other of the end of processing from the end of the compression processing, and the first processor 40A as the master processor is notified by this notification. It is determined whether or not the photographing signal processing of all the processors 40 has been completed.
[0064]
When the imaging signal processing in all the processors 40 is completed, the process proceeds from step 114 to step 116, and the image data of each responsible area 52 after the imaging signal processing is recorded by the processors 40 via the media I / F 24. 22 in order. That is, image data for one image divided by the first to third processors 40A to 40C is recorded on the same recording medium 22. At this time, the image data of each assigned area 52 divided by the first to third processors 40A to 40C may be recorded on the recording medium 22 as one file, or may be recorded on the recording medium 22 as separate files. May be recorded.
[0065]
To summarize the above, in the first embodiment, at the time of still image shooting and recording, the image signals of all the pixels are read from the CCD 16, and the shooting signal processing for one image is shared by the plurality of processors 40 and processed in parallel (division). However, when displaying a moving image, the image signal is thinned out from the CCD 16 and read out, and the image signal processing is performed by one processor 40 (specifically, the first processor 40A in the above). A reduced image of the original image obtained by photographing is displayed as a moving image as a through image.
[0066]
That is, at the time of still image shooting / recording, the shooting signal processing for one image is divided by the plurality of processors 40, so that the shooting interval can be shortened even in the digital camera 10 of 10 million pixel level. it can. In addition, it is possible to perform high-speed reading by thinning out and reading out the image signal from the CCD 16, thereby improving the frame rate, that is, realizing a moving image display function, and processing of a reduced image used for moving image display with one processor 40 (specifically Is performed only by the first processor 40A), and the other processors (specifically, the second and third processors 40B and 40C) are not driven, so that power saving can also be realized. In addition, since the reduced image is displayed as a moving image, there is also an effect that the photographer can grasp the entire state of the subject image captured by the digital camera 10.
[0067]
[Second Embodiment]
In the second embodiment, as shown in FIG. 4, a predetermined part of the image 50 (hereinafter referred to as a moving image display area), such as an image area to be focused on, for example, a moving image (through image) display. ) A case where only 58 is used will be described. The configuration of the digital camera may be the same as that of the first embodiment, and thus the description thereof is omitted here.
[0068]
The digital camera 10 according to the second embodiment is turned on when the photographer operates the power switch of the operation unit 28 and is activated, and the shooting mode is selected by operating the mode switch of the operation unit 28. In this case, the operation is as shown in FIG. In FIG. 6, the same processing steps as those in FIG. 4 are given the same step numbers, and detailed description thereof will be omitted below.
[0069]
That is, when the shooting mode is selected and the continuous shooting by the CCD 16 is started in step 100 of FIG. 6, the digital camera 10 reads out only the image signal corresponding to the area necessary for moving image display from the CCD 16 in the next step 102A.
[0070]
Specifically, as in the first embodiment, the signal charge accumulated in each photoelectric conversion cell 70 is transferred to the vertical transfer CCD, and the signal charge read to the vertical transfer CCD is horizontally transferred in synchronization with the vertical synchronization signal. By sequentially transferring to the path 74 side, signal charges for each row are sequentially transferred to the horizontal transfer path 82.
[0071]
When the signal charges in the row not including the moving image display area 58 are transferred to the horizontal transfer path 82, the supply of the horizontal drive signals φH1 and φH2 to the horizontal transfer electrode H of the horizontal transfer path 82 is stopped. Then, by applying a voltage of a predetermined level to the horizontal reset drain 88, the transferred signal charges of the row are swept out.
[0072]
On the other hand, when the signal charges of the row including the moving image display area 58 are transferred to the horizontal transfer path 82, the horizontal drive signals φH1 and φH2 are supplied to the horizontal transfer electrodes H of the horizontal transfer path 82. Then, the transferred signal charges of the row are sequentially output for each pixel.
[0073]
As a result, the rows not including the moving image display area 58 are swept out by the horizontal reset drain 88, and as a result, only the image signals of the rows including the moving image display area 58 are read out. Compared to reading out an image signal, the reading time can be greatly reduced. Specifically, in the example of FIG. 5, only the image signal corresponding to the region 60 composed of the row including the moving image display region 58 at the center of the image 50 is read from the CCD 16. The area 62 constituted by the rows not including the CCDs 16 to 58 located is swept out.
[0074]
When the signal charges of the row including the moving image display area 58 are transferred to the horizontal transfer path 82, the horizontal drive signals φH1 and φH2 are supplied to the horizontal transfer electrodes H of the horizontal transfer path 82, The signal charge of the row including the moving image display area 58 is sequentially output for each pixel, and when the corresponding signal charge is output in the moving image display area 58, the horizontal drive signal φH1 to the horizontal transfer electrode H is output. , ΦH2 is stopped, and a predetermined level of voltage is applied to the horizontal reset drain 88 to sweep out signal charges remaining in each horizontal transfer CCD at that time. As a result, the horizontal reset is also performed on the region 60A on the end side in the reading direction when reading the image signal for one row from the moving image display region 58 out of the region 60 including the moving image display region 58. It can be swept out by the drain 88, and the reading time can be further shortened.
[0075]
Further, as described in the first embodiment, thinning-out reading may be performed in the area 60 composed of rows including the moving image display area 58.
[0076]
Further, when the CCD 16 is configured so that signal charges can be swept out in both row and column units, unnecessary signal charges in the rows and columns are swept out by the CCD 16, and only the image signal in the moving image display area 58 is scanned. Read from.
[0077]
The analog image signal read out from the CCD 16 in this manner is input to the analog front end 18 and subjected to predetermined predetermined analog signal processing and A / D conversion, as in the first embodiment. And output from the analog front end 18.
[0078]
In the next step 104A in FIG. 6, the first processor 40A selects only the image signal corresponding to the moving image display area 58 from the row-unit digital image signal output from the analog front end 18, and as image data. Capture and video signal processing of the moving image display area 58 are performed. This selective capture can be easily realized by using a timing signal from the timing generator 32. Instead of the selective capture, digital image processing may be performed in which the first processor 40A captures image data and then cuts out the moving image display area 58.
[0079]
In the next step 106A, the first processor 40A outputs the image data after the photographing signal processing to the display monitor 26 via a display control circuit (not shown), thereby displaying a moving image (through image display). . Thus, when displaying an image obtained by continuous photographing by the CCD 16 as a moving image, only the moving image display area 58 that is a part of the image 50 is displayed as a moving image. Thereafter, until a shooting / recording instruction is input, the process returns from the next step 108 to step 102A, and among the subject images captured by the digital camera 10 in substantially real time, only the moving image display area 58 is a through image. When a moving image is displayed and a shooting / recording instruction is input, the process proceeds from step 108 to step 110, and the subsequent operation is the same as that of the first embodiment.
[0080]
To summarize the above, in the second embodiment, at the time of still image shooting and recording, the image signals of all the pixels are read from the CCD 16, and the shooting signal processing for one image is shared by the plurality of processors 40 and processed in parallel (division). However, at the time of moving image display, the image signal corresponding to the region 62 constituted by the rows outside the predetermined moving image display region 58 is swept out from the CCD 16 and one processor 40 (specifically in the above description) Specifically, the first processor 40A) performs the shooting signal processing only on the moving image display area 58 so that only a part of the original image obtained by shooting by the CCD 16 is displayed as a through image. Yes.
[0081]
That is, at the time of still image shooting / recording, the shooting signal processing for one image is divided by the plurality of processors 40, so that the shooting interval can be shortened even in the digital camera 10 of 10 million pixel level. it can. Further, the image signal corresponding to the area 62 unnecessary for moving image display is swept out from the CCD 16 and only the area 60 necessary for moving image display is read out, so that high-speed reading is possible, and the frame rate can be improved, that is, the moving image display function can be realized. In addition, the shooting signal processing of the moving image display area 58 for displaying moving images is performed by only one processor 40 (specifically, the first processor 40A), and the other processors (specifically, the second and third processors 40B). , 40C) is not driven, so that power saving can also be realized. In addition, by making the moving image display area 58 an image area to be focused, focusing can be performed with high accuracy.
[0082]
In the above description, for simplicity of explanation, the CCD 16 is described on the assumption that a CCD sensor of a type that reads an image signal in the same direction as the image compression processing direction (referred to as a horizontal reading type) is used. However, the present invention is not limited to this, and a CCD sensor of a type in which the compression direction and the reading direction that are attracting attention for reading out an image signal at a higher speed are orthogonal (referred to as a vertical reading type) may be used. Good. In the case of using a vertical readout type CCD sensor, it is necessary to perform a process of rearranging the arrangement of each pixel of the image data vertically and horizontally and rotating it by 90 degrees. The processing can be performed at high speed, and even if a rotation process is added to the photographing signal process, the advantages of using a vertical readout type CCD can be enjoyed. In other words, by dividing the image data using a plurality of processors 40, it is possible to execute processing that has been abandoned in terms of processing speed in the prior art as photographing signal processing.
[0083]
【The invention's effect】
As described above, the present invention has an excellent effect that in a digital camera, a moving image display function can be realized even when the number of pixels is increased, and a shooting interval can be shortened and power can be saved.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an electric system of a digital camera according to a first embodiment.
FIG. 2 is a conceptual diagram showing a relationship between each assigned area and a capture area determined for dividing one image by first to third processors.
FIG. 3 is a diagram showing an example of the configuration of a CCD image sensor provided with a sweeping unit that sweeps signal charges in unnecessary portions.
FIG. 4 is a flowchart showing an operation when a shooting mode is selected by the digital camera according to the first embodiment.
FIG. 5 is a conceptual diagram for explaining an image area used for moving image display in the digital camera according to the second embodiment.
FIG. 6 is a flowchart showing an operation when a shooting mode is selected by the digital camera according to the second embodiment.
[Explanation of symbols]
10 Digital camera
12 Optical unit
14 Drive circuit
16 CCD sensor
18 Analog front end
20 Digital processing unit
22 Recording media
24 Media I / F
26 Display monitor
28 Operating means
32 Timing Generator
34 Analog processing circuit
36 A / D converter
40 processor
50 images
52 Area in charge
58 Movie display area
88 Horizontal reset drain

Claims (3)

An image sensor having a sweeping unit that receives light corresponding to a subject image, accumulates charges corresponding to the amount of received light for each pixel to generate an image signal, and sweeps the accumulated charges;
Reading means for reading out the image signal from the image sensor;
A plurality of photographing signal processing means for performing predetermined photographing signal processing on the image data based on the image signal read by the reading means and sharing the photographing signal processing for one subject image in parallel;
Recording means for recording the image data processed in parallel by the plurality of photographing signal processing means on a recording medium;
A digital camera comprising display means for displaying the subject image,
When the subject image is displayed as a moving image on the display unit, the reading unit operates the sweeping unit to read out the image signal from the image sensor at a predetermined period, and reads the image data corresponding to the read result. A digital camera characterized in that only one of the plurality of imaging signal processing means is in charge of imaging signal processing. An image sensor having a sweeping unit that receives light corresponding to a subject image, accumulates charges corresponding to the amount of received light for each pixel to generate an image signal, and sweeps the accumulated charges;
Reading means for reading out the image signal from the image sensor;
A plurality of photographing signal processing means for performing predetermined photographing signal processing on the image data based on the image signal read by the reading means and sharing the photographing signal processing for one subject image in parallel;
Recording means for recording the image data processed in parallel by the plurality of photographing signal processing means on a recording medium;
A digital camera comprising display means for displaying the subject image,
When the subject image is displayed as a moving image on the display means, the reading means operates the sweeping means to read out an image signal of a part of the subject image from the image sensor, and Only one of the plurality of photographing signal processing means is in charge of the photographing signal processing for image data. The digital camera according to claim 2, wherein a part of the subject image is an image region for focusing the subject image.

Images