JP2003163940A - Digital camera and imaging method thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera for preparing color image data that accurately show color information on an object. <P>SOLUTION: The digital camera has a color filter array 22 where a color film 20 having three colors R, G, and B is aligned two-dimensionally, an area image sensor 26 where a plurality of light-sensitive sections 24 for receiving the transmission light of the color filter 20 each are aligned two-dimensionally, and a signal processing section that prepares color image data expressing a subject based on the output signal of the area image sensor 26. Additionally, a drive section is provided, where the drive section drives a color filter array 22 relatively to the area image sensor 26, and allocates the color filter 20 of all colors of the R, G, and B to each of the plurality of light-sensitive sections 24 by time sharing. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera and an image pickup method by the digital camera.

[0002]

2. Description of the Related Art Conventionally, a digital camera is known in which an image of a subject is picked up by an area image sensor in which a plurality of photosensitive portions are two-dimensionally arranged and color image data representing the subject image is created. One of the color image pickup methods of such a digital camera is a method of obtaining color information by providing a color filter array in which color filters of a plurality of colors are two-dimensionally arranged in a photosensitive portion of an area image sensor. Heretofore, various color filter array systems in a color filter array have been proposed. FIG. 9 schematically shows the Bayer method. In the Bayer method, G (Green) color filters close to the luminance signal are arranged in a checkered pattern, and R (Red) and B (Blue) color filters are arranged in a checkered pattern in the remaining portion.

[0003]

According to the conventional color image pickup system using a color filter array, light passing through one color filter is incident on each photosensitive portion of the area image sensor. Therefore, the color information obtained based on the charges accumulated in one photosensitive portion when the subject is scanned is only for one color. For information on the colors that cannot be obtained in each photosensitive section,
Interpolation is performed using the color information obtained by the other photosensitive portions near each photosensitive portion. Therefore, the conventional color imaging method has a problem that the color information is not accurate. The present invention has been made in view of the above problems, and an object thereof is to provide a digital camera that creates color image data that more accurately represents color information of a subject, and an imaging method by the digital camera. .

[0004]

According to the digital camera of the present invention, there are provided a color filter array in which color filters of a plurality of colors are two-dimensionally arranged and a plurality of photosensitive portions which respectively receive transmitted light of the color filters. A two-dimensionally arranged area image sensor, a signal processing unit that creates color image data representing a subject based on an output signal of the area image sensor and stores the color image data in a recording medium, and a color filter array for the area image sensor. And a driving unit that relatively moves and allocates color filters of all colors to each of the plurality of photosensitive units in a time division manner.

According to this digital camera, the color filter array is moved relative to the area image sensor, and the color filters of all colors are time-divisionally assigned to the photosensitive parts of the area image sensor. Transmitted light is time-divided and is received by each photosensitive portion. Therefore, according to this digital camera, all the color information can be obtained from each photosensitive section, and thus color image data that more accurately represents the color information of the subject can be created.

Further, according to the digital camera of the present invention, the drive section operates in one of two modes depending on the selection operation of the operator. Here, the two types of modes are (A) a first imaging mode in which the color filter array is relatively moved with respect to the area image sensor and color filters of all colors are time-divided and assigned to each of the plurality of photosensitive portions, and ( B) A second imaging mode in which a color filter of any one color is assigned to each of the plurality of photosensitive parts without moving the color filter array with respect to the area image sensor.

According to this digital camera, it is possible to obtain color image data that more accurately represents the color information of the object when the image is picked up in the first image pickup mode, and the object which moves at high speed is picked up when the image is picked up in the second image pickup mode. It is possible to obtain color image data that accurately represents the still image of.

Further, according to the digital camera of the present invention, since the color filters of a plurality of colors are arranged in stripes in the color filter array, the relative moving distance of the color filter array can be reduced. The present invention can be specified not only as a digital camera invention but also as a method invention and a program invention.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plurality of embodiments showing the embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 2 is a sectional view schematically showing the internal structure of a digital camera 10 according to the first embodiment of the present invention.

The optical system 12 includes a lens 14 and an optical diaphragm 16.
It is composed of. The lens 14 is provided in the opening of the housing 18 and forms a subject image on the photosensitive portion 24 of the area image sensor 26. As the lens 14, a converging lens having a fixed magnification may be used, or a zoom lens may be used. The optical diaphragm 16 adjusts the amount of light incident on the area image sensor 26.

The area image sensor 26 is mounted on a substrate 27 fixed to the housing 18. The area image sensor 26 has a plurality of photosensitive portions 24 arranged in a lattice on an imaginary plane perpendicular to the optical axis O of the lens 14. Each photosensitive section 24 is composed of a photoelectric conversion element such as a photodiode. The area image sensor 26 accumulates charges obtained by photoelectrically converting the light received by each photosensitive section 24 for a certain period of time, scans the accumulated charges, and outputs an electric signal (image signal).
Output as. C as the area image sensor 26
Any of a CD type sensor, a MOS type sensor, a laminated type sensor, an amplification type sensor and the like may be used.

The color filter array (hereinafter, simply referred to as a filter array) 22 includes color filters 20 of a plurality of colors arranged in a lattice on a virtual plane perpendicular to the optical axis O of the lens 14. The filter array 22 is moved by an actuator (ACT) 28 including a micromotor, a piezoelectric element, a solenoid and the like.

FIG. 3 is a schematic view showing the arrangement of the color filters 20. The filter array 22 has three R, G, and B
The primary color filters 20 are arranged in a diagonal stripe pattern. Here, the diagonal stripe shape means a state in which the color filters 20 of the same color are continuous in a direction intersecting with each other at 45 ° with respect to vertical or horizontal parallel lines (lattice parallel lines) forming a grid that defines the arrangement of the filter array 22. .

FIG. 1 is a schematic diagram showing an operation in which the filter array 22 moves relative to the area image sensor 26. The upper left column, the lower left column, and the right column of each of the diagrams in FIGS. 1A to 1C are a schematic front view, a schematic bottom view, and a schematic side view of the filter array 22 and the area image sensor 26, respectively.

The filter array 22 is provided in a position parallel to the area image sensor 26 at a close distance to the area image sensor 26. The filter array 22 is movably provided in a direction parallel to the vertical or horizontal lattice parallel lines that define the arrangement of the color filters 20. Hereinafter, the direction parallel to the vertical grid parallel lines that define the arrangement of the color filters 20 is referred to as the vertical direction, and the direction parallel to the horizontal grid parallel lines is referred to as the horizontal direction. The vertical and horizontal arrangement pitches of the color filters 20 are equal to the vertical and horizontal arrangement pitches of the photosensitive portions 24 of the area image sensor 26, respectively.

FIG. 4 is a block diagram showing the configuration of the digital camera 10. The optical system drive unit 30 is composed of an actuator such as a stepping motor and its drive circuit. The optical system driving unit 30 drives the lens 14 to focus it. In addition, the optical system driving unit 30 includes the optical diaphragm 1
6 is driven to adjust the amount of light incident on the area image sensor 26.

The sensor drive unit 40 is an electronic circuit that drives the area image sensor 26 and the actuator (ACT) 28. The sensor drive unit 40 includes, for example, a synchronization signal generator, a drive timing generator, a D / A converter, an amplifier circuit, and the like.

The sensor driving unit 40 uses, for example, a shift pulse when the CCD type area image sensor 26 is used.
By generating a drive pulse such as a vertical transfer pulse, a horizontal transfer pulse, or a shutter gate pulse for controlling the charge storage time and sequentially inputting it to the area image sensor 26,
The area image sensor 26 is driven. The exposure time of the area image sensor 26 may be controlled by an electronic shutter that uses a shutter gate pulse, or may be controlled by a mechanical shutter that operates mechanically. Further, the sensor driving unit 40 sequentially inputs a driving pulse such as a vertical driving pulse for moving the filter array 22 in the vertical direction and a horizontal driving pulse for moving the filter array 22 in the horizontal direction to the actuator 28, The actuator 28 is driven.

The sensor driving unit 40 is the sensor driving unit 4
A mode register for setting the operation mode inside 0 is provided. The sensor drive unit 40 drives the area image sensor 26 and the actuator 28 in a sequence according to the value set in the mode register.

Sensor drive unit 4 operating in the first image pickup mode
0 is a process of driving the actuator 28 so that the filter array 22 moves relative to the area image sensor 26 for one image pickup for recording one still image, and a signal charge is accumulated in the area image sensor 26 for a predetermined time. Then, the processing of scanning the signal charges is alternately repeated a number of times (three times) equal to the number of colors of the color filter 20.
The actuator 28 driven by the sensor driving unit 40 in the first imaging mode filters the filter array 22 so that the light transmitted through the color filters 20 of R, G, and B colors respectively enters the photosensitive units 24 of the area image sensor 26 once. To move.

Sensor drive unit 4 operating in the second imaging mode
In the case of 0, in one image pickup for recording one still image, the signal charge is accumulated in the area image sensor 26 for a predetermined time and the accumulated signal charge is scanned only once. The sensor drive unit 40 that operates in the second imaging mode does not drive the actuator 28.

The detection unit 44 includes a focus information detection unit 46 and a brightness detection unit 48, acquires data necessary for setting an appropriate image pickup condition, and inputs the data to the control unit 70. The focus information detection unit 46 detects focus information necessary for automatic focus adjustment of the lens 14. The brightness detection unit 48 uses the optical diaphragm 16
Aperture value (aperture amount) setting and area image sensor 2
The brightness of the subject necessary for setting the charge accumulation time of 6 is detected.

The processing unit 50 includes an analog front end (AFE) 52 and a digital image processing unit 60, creates digital color image data based on the analog image signal output from the area image sensor 26, and creates it. The color image data is stored in the non-volatile memory 64 as a recording medium.

The AFE 52 is an area image sensor 26.
The analog image signal output from the device is converted into a digital image signal and output. The AFE 52 has a correlated double sampling (CDS) unit 54, an automatic gain control (AGC) unit 56, and an A / D conversion unit 58. CD
The S unit 54 performs a process of reducing noise included in the analog image signal. The AGC unit 56 adjusts the level of the analog image signal by adjusting the gain. The A / D converter 58 quantizes the analog image signal that has been subjected to each of the above processes into a digital image signal of a predetermined gradation and outputs the digital image signal.

The digital image processing unit 60 has an AFE 52.
It has a DSP (Digital Signal Processor) that creates color image data from the digital image signal output from. The digital image processing unit 60 has a mode register for setting an operation mode inside the digital image processing unit 60. The control unit 70, which will be described later, operates the digital image processing unit 60 in the first imaging mode when operating the sensor driving unit 40 in the first imaging mode, and performs the digital image processing when operating the sensor driving unit 40 in the second imaging mode. Values are set in the mode registers of the digital image processing unit 60 and the sensor driving unit 40 so that the unit 60 operates in the second imaging mode. The digital image processing unit 60 creates color image data by a method according to the value set in the mode register.

The digital image processing section 60 operates as follows in the first image pickup mode. That is, when the sensor driving unit 40 operates in the first imaging mode, the transmitted light of the R, G, and B color filters 20 is incident on each photosensitive unit 24,
The image signal corresponding to each color of R, G, B is A for each pixel.
It is input from the FE 52 to the digital image processing unit 60.
As a result, the digital image processing unit 60 operating in the first imaging mode does not perform interpolation using the image signals of neighboring pixels, and outputs R, G for all pixels from the actually input image signals of three colors of each pixel. , B, the tone values of all colors are obtained.

Further, the digital image processing section 60 operates as follows in the second image pickup mode. That is, when the sensor driving unit 40 operates in the second imaging mode, the light transmitted through the color filter 20 of any one of R, G, and B colors is applied to each of the photosensitive units 24.
Image signal corresponding to any one of R, G, and B colors is input from the AFE 52 to the digital image processing unit 60 for each pixel, so that an image signal corresponding to the gradation value of two colors is input to each pixel. Run out. Therefore, the digital image processing unit 60 operating in the second imaging mode uses the image signals of the neighboring pixels to interpolate the gradation values corresponding to the insufficient image signal, and all the R, G, B colors for all pixels. To obtain the gradation value of.

The digital image processing unit 60, in addition to the creation of color image data, performs various kinds of processing such as gamma correction, defective pixel correction, automatic white balance processing, contour correction, white clip processing, and subject extraction processing. Also implemented in mode.

Further, the digital image processing section 60 compresses the created color image data and stores it in the non-volatile memory 64 as a recording medium in any imaging mode. The compression of color image data is performed by, for example, discrete cosine transform (DC
T) and JPEG compression technology by Huffman coding. A flash memory, a magnetic disk, a magneto-optical disk or the like is used as the non-volatile memory 64 for storing the color image data. The non-volatile memory 64 may be detachably or non-detachably connected to the housing 18.

Further, the digital image processing unit 60 reduces the created color image data by the conversion processing of the number of pixels to create reduced image data in any image pickup mode. In the conversion processing of the number of pixels, the number of pixels of the liquid crystal display (LCD) 84 of the display unit 80 (320 × 240 pixels) or the number of pixels of the thumbnail image defined by the standard (160 × 120 pixels) is used for the pixel information forming the image data. ) And so on.

The image signal processed by the digital image processing unit 60 and the color image data created by the digital image processing unit 60 are temporarily stored in a work memory (for example, the RAM 76 of the control unit 70) as needed. Can be stored statically. Further, various kinds of processing performed by the digital image processing unit 60 may be replaced with processing by a computer program executed by the control unit 70.

The display section 80 comprises an LCD 84 and an LCD drive section 82. The LCD drive section 82 uses the reduced image data created by the digital image processing section 60 on the LCD 84.
To display. The LCD 84 may be a transmissive type having a backlight, or a reflective type or a semi-transmissive type in which the backlight can be omitted.

The external interface (I / F) 100 is
It is configured according to various protocols such as USB and Bluetooth, and is used to transfer color image data to an external image processing device such as a personal computer, a television receiver, a projector and the like.

The operation section 90 detects a switch operation or a button operation by the user and mainly inputs data to the control section 70. The operation unit 90 includes a mode selection switch 92 for performing an operation of selecting an imaging mode. The mode selection switch 92 selects either the first imaging mode for obtaining accurate color information or the second imaging mode suitable for imaging a fast-moving subject. In addition to the mode selection switch 92, the operation unit 90 includes various switches or buttons such as a power switch 96 for turning the power on / off and a release switch 98 for inputting an instruction to execute imaging.

The control unit 70 has a CPU 72, a ROM 74 and a RAM 76, and has an optical system driving unit 30 and a sensor driving unit 4.
0, processing unit 50, display unit 80, operation unit 90, I / F 10
It is connected to 0 etc. by a bus. The control unit 70 includes the ROM 7
4 by executing the control program stored in advance, the optical system drive unit 30, the sensor drive unit 40, the processing unit 50, the display unit 80, the operation unit 90 based on the data input from the operation unit 90, the detection unit 44 and the like. , I / F 100, etc. are controlled to realize a subject image pickup function. The control unit 70 determines the value of the mode register of the sensor drive unit 40 and the digital image processing unit 60 according to the imaging mode selected by the mode selection switch 92.
Set the value of the mode register of.

The configuration of the digital camera 10 has been described above. The operation of the digital camera 10 when the user selects the first imaging mode with the mode selection switch 92 will be described below.

(1) When the first image pickup mode is selected by the mode selection switch 92, the controller 70 causes the sensor driver 40 to operate.
A predetermined value is set in each mode register of the digital image processing unit 60 and the image pickup mode of the sensor driving unit 40 and the digital image processing unit 60 is set to the first image pickup mode.

(2) Then, when the release switch 98 is half-pressed by the user, the control unit 70 adjusts the charge accumulation time, the aperture, and the focus of the area image sensor 26 according to the information acquired from the detection unit 44. (3) Next, when the user fully presses the release switch 98 from the half-pressed state, the control unit 70 controls the optical system driving unit 30, the sensor driving unit 40, and the processing unit 50 to store the color image data in a nonvolatile manner. It records in the memory 64.

The operation in which the sensor drive unit 40 drives the filter array 22 and the area image sensor 26 when the release switch 98 is fully pressed in the first image pickup mode will be described below with reference to FIG. (I) FIG. 1A shows the home position of the filter array 22. In this home position, the filter array 22 is localized at a position where the transmitted light of any one of the color filters 20 is incident on each photosensitive portion 24 of the area image sensor 26. When the release switch 98 is fully pressed, the sensor drive unit 40 first inputs a drive pulse for scanning the electric charge accumulated in the state where the filter array 22 is localized at the home position, to the area image sensor 26. An image signal for the first color is output from the area image sensor 26 for each photosensitive section 24.

(Ii) Next, as shown by the arrow in FIG. 1A, the sensor drive unit 40 moves the filter array 22 in the vertical direction by a distance corresponding to the arrangement pitch of the color filters 20 in the vertical direction. , And is localized at the position shown in FIG. When the filter array 22 is located at this position, the color filter 20 adjacent to the photosensitive member 24 adjacent to the vertically lower side of the color filter 20 allocated when the filter array 22 is at the home position is allocated to each photosensitive section 24. Therefore, in this position, the filter array 22
The photosensitive section 24 which has received the transmitted light of the R color filter 20 at the home position of the same receives the transmitted light of the G color filter 20 and the G position of the G color filter 2 at the home position.
The photosensitive section 24 that receives the transmitted light of 0 receives the transmitted light of the B color filter 20, and the photosensitive section 24 that receives the transmitted light of the B color filter 20 at the home position transmits the transmitted light of the R color filter 20. Receive light. Then, the sensor drive unit 40 inputs a drive pulse for scanning the electric charge accumulated in the position where the filter array 22 is localized at this position to the area image sensor 26, whereby each photosensitive unit 24.
The image signal of the second color about the area image sensor 26
To output from.

(Iii) Subsequently, the sensor drive unit 40 is shown in FIG.
As indicated by the arrow in (b), the filter array 2 is separated by a distance corresponding to the arrangement pitch of the color filters 20 in the horizontal direction.
After moving 2 in the horizontal direction, it is localized at the position shown in FIG. When the filter array 22 is located at this position, the color filters 20 assigned to the respective photosensitive portions 24 when the filter array 22 was located at the previous localization position were used.
The color filter 20 adjacent to the right side in the horizontal direction is assigned. Therefore, in this position, the filter array 2
The photosensitive section 24 that receives the transmitted light of the R color filter 20 at the home position of 2 and the transmitted light of the G color filter 20 at the previous localization position is the B color filter 20.
Of the color filter 20 of the R color filter 20 at the home position of the filter array 22 and the light of the B color filter 20 at the previous localization position. Of the B color filter 20 at the home position of the filter array 22 and the transmitted light of the R color filter 20 at the previous localization position.
The transmitted light of the color filter 20 is received. Then, the sensor drive unit 40 inputs a drive pulse for scanning the electric charge accumulated in the position where the filter array 22 is localized at this position to the area image sensor 26, and thereby the image signal of the third color is supplied to each photosensitive unit 24. The area image sensor 26 outputs.

(Iv) Subsequently, the sensor driving unit 40 is shown in FIG.
The filter array 22 is moved in the direction indicated by the arrow in (c) and returned to the home position shown in FIG. still,
By setting the home position to a different position each time without performing the process of (iv), the number of movements of the filter array 22 required for one imaging may be reduced. Further, the time for which the filter array 22 is localized at each position in FIGS. 1A to 1C is set longer than the time for accumulating the signal charges in the area image sensor 26 at each position.

Next, the digital camera 10 when the user selects the second image pickup mode with the mode selection switch 92.
The operation of will be described. (1) When the second image pickup mode is selected by the mode selection switch 92, the control unit 70 sets a predetermined value in each mode register of the sensor drive unit 40 and the digital image processing unit 60, and the sensor drive unit 40 and the digital image processing unit 60. Image processing unit 60
The image pickup mode of is set to the second image pickup mode.

(2) Subsequently, when the release switch 98 is half-pressed by the user, the control unit 70 adjusts the charge accumulation time, the diaphragm, and the focus of the area image sensor 26 according to the information acquired from the detection unit 44. (3) Next, when the user fully presses the release switch 98 from the half-pressed state, the control unit 70 controls the optical system driving unit 30, the sensor driving unit 40, and the processing unit 50 to store the color image data in a nonvolatile manner. It records in the memory 64. At this time, the sensor drive unit 40 inputs to the area image sensor 26 a drive pulse for scanning the charges accumulated in the area image sensor 26 with the filter array 22 being localized at the home position shown in FIG. Thus, the area image sensor 26 outputs only one color image signal for each photosensitive section 24.

According to the digital camera 10 of the first embodiment described above, when the first image pickup mode is selected, the filter array 22 is moved relative to the area image sensor 26 in the vertical and horizontal directions. By allocating the color filters 20 for all colors of R, G, and B to the respective photosensitive parts 24 in a time-division manner, the transmitted light of the color filters 20 for all the colors of R, G, B is time-divided to the respective photosensitive parts 24. Can receive light. Therefore, according to the digital camera 10, in the first imaging mode, each photosensitive section 24
Since it is possible to obtain all the color information from, it is possible to create color image data that more accurately represents the color information of the subject.

According to the digital camera 10 of the first embodiment, when the second image pickup mode is selected, color image data can be created by scanning the signal charge accumulated in the area image sensor 26 once for each image pickup. It is possible to obtain color image data that accurately represents a still image of a subject that moves at high speed.

(Second Embodiment) FIG. 5 is a schematic view showing an operation in which the filter array 22 of the digital camera according to the second embodiment of the present invention moves relative to the area image sensor 26. The digital camera according to the second embodiment is different from the digital camera 10 according to the first embodiment only in the moving path of the filter array 22 in the first imaging mode, and the other elements are common.

In the second embodiment, when the release switch 98 is fully pressed in the first image pickup mode, the sensor drive unit 4
0 is the filter array 22 and the area image sensor 26
The operation of driving the motor will be described with reference to FIG. (I) When the release switch 98 is fully pressed, the sensor drive unit 40 first moves to the position shown in FIG.
By inputting the drive pulse for scanning the electric charge accumulated in the state where the filter array 22 is localized at the home position shown in (a) to the area image sensor 26,
An image signal for the first color is output from the area image sensor 26 for each photosensitive section 24.

(Ii) Next, as shown by the arrow in FIG. 5A, the sensor drive unit 40 filters the color filters 20 by a distance corresponding to the vertical arrangement pitch, as in the case of the first embodiment. After moving the array 22 in the vertical direction, it is localized at the position shown in FIG. In this position, R when the filter array 22 is in the home position,
The photosensitive portions 24 that have respectively received the transmitted light of the G and B color filters 20 receive the transmitted light of the G, B and R color filters 20, respectively. Then, the sensor drive unit 40 inputs a drive pulse for scanning the electric charge accumulated in the position where the filter array 22 is localized at this position to the area image sensor 26, so that the image signal of the second color is supplied to each photosensitive unit 24. The area image sensor 26 outputs.

(Iii) Subsequently, the sensor driving section 40 is shown in FIG.
As indicated by an arrow in (b), the filter array 2 is separated by a distance corresponding to the arrangement pitch of the color filters 20 in the vertical direction.
After moving 2 further in the vertical direction, it is localized at the position shown in FIG. When the filter array 22 is located at this position, the color filters 20 adjacent to the color filters 20 that are vertically below the color filters 20 that were allocated when the filter array 22 was at the previous localization position are allocated to the respective photosensitive portions 24. Since the filter array 22 adopts a diagonal stripe arrangement, even if the moving direction of the filter array 22 is set to the vertical direction when the filter array 22 is moved from the home position for the second time, the R and G positions at the home position are set. , B color filters 20 are received respectively, and G, B, and R color filters 20 are received at the previous localization positions.
It is possible to cause the photosensitive portions 24 that have respectively received the transmitted light of B to receive the transmitted light of the B, R, and G color filters 20, respectively. Then, the sensor drive unit 40 inputs a drive pulse for scanning the electric charge accumulated in the position where the filter array 22 is localized at this position to the area image sensor 26, and thereby the image signal of the third color is supplied to each photosensitive unit 24. The area image sensor 26 outputs. (Iv) Subsequently, the sensor drive unit 40 moves the filter array 22 in the direction indicated by the arrow in FIG. 5 (c), and returns it to the home position shown in FIG. 5 (a).

As described above, in the digital camera of the second embodiment, when the first image pickup mode is selected, the filter array 22 is relatively moved only in the vertical direction with respect to the area image sensor 26, and each photosensitive portion 2 of the area image sensor 26 is moved.
4 by allocating the color filters 20 for all R, G, and B colors in a time-division manner to the color filters 2 for all R, G, and B colors.
The transmitted light of 0 can be time-divided and received by each photosensitive portion 24. Therefore, according to the digital camera of the second embodiment, it is possible to obtain color image data that more accurately represents the color information of the subject in the first imaging mode. still,
In the second embodiment, the same effect can be obtained even if the filter array 22 is moved not only in the vertical direction but in the horizontal direction or in the oblique direction as described above.

(Third Embodiment) FIG. 6 shows an arrangement of a color filter 20 of a digital camera according to a third embodiment of the present invention and an area image sensor 26 of a filter array 200.
FIG. 6 is a schematic diagram showing an operation of moving relative to the above. The digital camera according to the third embodiment is different from the digital camera according to the first embodiment in the arrangement of the color filters 20 and the movement path of the filter array 200 in the first imaging mode, and the other elements are common. ing.

First, in the third embodiment, as shown in FIG.
Instead of the diagonal stripe filter array 22, R,
A filter array 200 in which color filters 20 of three primary colors G and B are arranged in a vertical stripe pattern is used. Here, the vertical stripe shape means a state in which columns in which the color filters 20 of the same color are continuously arranged in the vertical direction are sequentially arranged in the horizontal direction. Also in the filter array 200, the arrangement pitches of the color filters 20 in the vertical direction and the horizontal direction are equal to the arrangement pitches of the photosensitive portions 24 of the area image sensor 26 in the vertical direction and the horizontal direction, respectively.

Next, in the third embodiment, the operation in which the sensor drive unit 40 drives the filter array 200 and the area image sensor 26 when the release switch 98 is fully pressed in the first image pickup mode will be described with reference to FIG. . (I) FIG. 6A shows the home position of the filter array 200. At this home position, the filter array 200 is localized at a position where the transmitted light of any one of the color filters 20 is incident on each photosensitive portion 24 of the area image sensor 26. When the release switch 98 is fully pressed, the sensor drive unit 40 first inputs a drive pulse for scanning the electric charge accumulated in the state where the filter array 200 is located at the home position to the area image sensor 26, thereby The area image sensor 26 outputs the image signal of the first color for the photosensitive section 24.

(Ii) Next, the sensor driving section 40 is shown in FIG.
After moving the filter array 200 in the horizontal direction perpendicular to the stripe direction of the color filter 20 by a distance corresponding to the arrangement pitch in the horizontal direction,
It is localized at the position shown in FIG. When the filter array 200 is located at this position, the color filter 20 adjacent to the horizontal right side of the color filter 20 allocated when the filter array 22 is at the home position is allocated to each photosensitive section 24. Therefore, at this position, the photosensitive portions 24 that have received the transmitted light of the R, G, and B color filters 20 at the home position of the filter array 200 respectively receive the transmitted light of the G, B, and R color filters 20. And the sensor drive unit 40
Inputs a drive pulse for scanning the charge accumulated in the position where the filter array 200 is localized at this position to the area image sensor 26, so that the image signal of the second color is output from the area image sensor 26 for each photosensitive section 24. Output.

(Iii) Next, the sensor driving section 40 is shown in FIG.
As shown by the arrow in (b), the filter array 200 is further moved in the horizontal direction of the color filter 20 by a distance corresponding to the arrangement pitch in the horizontal direction, and then, FIG.
Localize to the position shown in. Filter array 2 at this position
00, there is a filter array 20 in each photosensitive section 24.
The color filter 20 adjacent to the horizontal right side of the color filter 20 that was assigned when 0 was at the previous localization position is assigned. Therefore, the photosensitive section 24 receives the transmitted light of the R, G, B color filters 20 at the home position of the filter array 200 and the transmitted light of the G, B, R color filters 20 at the previous localization position, respectively. At this position, the transmitted lights of the B, R, and G color filters 20 are received. Then, the sensor drive unit 40 inputs a drive pulse for scanning the electric charge accumulated in the position where the filter array 200 is localized at this position to the area image sensor 26, and thereby the image signal of the third color is supplied to each photosensitive unit 24. The area image sensor 26 outputs. (Iv) Subsequently, the sensor drive unit 40 moves the filter array 200 in the direction indicated by the arrow in FIG.
Return to the home position shown in.

As described above, in the digital camera of the third embodiment, the filter array 200 is moved relative to the area image sensor 26 only in the horizontal direction, and all the R, G, B colors are applied to the photosensitive portions 24 of the area image sensor 26. R, G, B by allocating the color filters 20 of
The light transmitted through the color filters 20 of all colors can be time-divided and received by each photosensitive section 24. Therefore, according to the digital camera of the third embodiment, it is possible to obtain color image data that more accurately represents the color information of the subject in the first imaging mode.

Instead of the vertical stripe arrangement described above, a horizontal stripe arrangement may be adopted in which the rows of the color filters 20 of the same color are arranged in the vertical direction in color sequence. In that case, the filter array is moved in the vertical direction perpendicular to the stripe direction.

(Fourth Embodiment) FIG. 7 shows the configuration of a filter array 250 of a digital camera according to the fourth embodiment of the present invention, and the filter array 22 is an area image sensor 26.
FIG. 6 is a schematic diagram showing an operation of moving relative to the above. The digital camera according to the fourth embodiment is different from the digital camera 10 according to the first embodiment in the configuration of the filter array 250 and the operation at the time of imaging, and the other elements are common.

First, in the fourth embodiment, as shown in FIG.
Instead of the primary color filter 20, a filter array 250 in which four complementary color filters 252 of Ye, Mg, G and Cy are arranged is used. The filter array 250 of the fourth embodiment employs an array form of complementary color filters in a color image pickup method which is conventionally called a field color difference sequential method. That is, this arrangement form is
Color filters 252 of which the color filters 252 are alternately arranged in the horizontal direction, a second column of color filters 252 of Ye and Cy which are alternately arranged in the horizontal direction, and the color filters 252 of Mg and G are the first column. Represents a third column alternately arranged in the reverse direction in the horizontal direction and a fourth column in which the Ye and Cy color filters 252 are alternately arranged in the horizontal direction in the same order as the second column. It is a form that is repeatedly arrayed in. If such an array form is adopted, the same processing as in the case of the conventional field color difference sequential method can be performed in the second imaging mode of the sensor driving section 40 and the digital image processing section 60. Also in the filter array 250, the arrangement pitches of the color filters 252 in the horizontal direction and the vertical direction are equal to the arrangement pitches of the photosensitive portions 24 of the area image sensor 26 in the horizontal direction and the vertical direction, respectively.

Next, in the fourth embodiment, the operation in which the sensor drive unit 40 drives the filter array 250 and the area image sensor 26 when the release switch 98 is fully pressed in the first image pickup mode will be described with reference to FIG. . (I) FIG. 7A shows the home position of the filter array 250. At this home position, the filter array 250 is localized at a position where the light transmitted through any one of the color filters 252 is incident on each photosensitive portion 24 of the area image sensor 26. When the release switch 98 is fully pressed, the sensor drive unit 40 first inputs a drive pulse for scanning the charge accumulated in the state where the filter array 250 is localized at the home position to the area image sensor 26, The area image sensor 26 is caused to output the image signal of the first color for the photosensitive section 24.

(Ii) Next, as shown by the arrow in FIG. 7A, the sensor drive unit 40 is arranged so that the filter array 25 is separated by a distance corresponding to the arrangement pitch of the color filters 252 in the vertical direction.
After moving 0 in the vertical direction, it is localized at the position shown in FIG. When the filter array 250 is located at this position, each photosensitive section 24 is adjacent to the color filter 25 vertically below the color filter 252 assigned when the filter array 250 is at the home position.
2 is assigned. Therefore, at this position, the photosensitive portion 24 that has received the transmitted light of the Ye color filter 252 at the home position of the filter array 250 has Mg and G
Of the color filter 252, the photosensitive portion 24 receives the transmitted light of the Mg color filter 252 at the home position and receives the transmitted light of the color filter 252 of either Ye or Cy. . Further, at this position, the photosensitive section 24, which has received the transmitted light of the G color filter 252 at the home position, receives the transmitted light of either one of the Ye and Cy color filters 252, and at the home position of the Cy color filter 252. The photosensitive unit 24 that receives the transmitted light receives the transmitted light of the color filter 252 of either Mg or G. Then, the sensor driving unit 40 sets the filter array 250 at this position.
By inputting the drive pulse for scanning the electric charge accumulated in the position where is localized to the area image sensor 26,
An image signal for the second color is output from the area image sensor 26 for each photosensitive section 24.

(Iii) Subsequently, the sensor drive unit 40 is shown in FIG.
As indicated by the arrow in (b), the filter array 250 is moved in the horizontal direction by a distance corresponding to the arrangement pitch of the color filters 252 in the horizontal direction, and then localized at the position shown in FIG. 7C. When the filter array 250 is located at this position, the color filters 2 adjacent to the right side in the horizontal direction of the color filter 252 assigned to each photosensitive section 24 when the filter array 250 was at the previous localization position.
52 is assigned. Therefore, at this position, the photosensitive portion 24 that receives the transmitted light of the Ye color filter 252 at the home position of the filter array 250 and the transmitted light of the color filter 252 of either Mg or G at the previous localization position is the photosensitive unit 24. And G, the transmitted light of the other color filter 252 is received, the transmitted light of the Mg color filter 252 is received at the home position, and the transmitted light of the Ye or Cy color filter 252 at the previous localization position. The photosensitive portion 24 receiving the light is Ye and Cy.
The transmitted light of the other color filter 252 is received. Also, at this position, the transmitted light of the G color filter 252 is received at the home position and Y is returned at the previous localization position.
The photosensitive portion 24 that receives the transmitted light of the color filter 252 of either e or Cy receives the transmitted light of the other color filter 252 of Ye or Cy, and the transmitted light of the color filter 252 of Cy at the home position. And the photosensitive section 24 which has received the transmitted light of one of the color filters 252 of Mg and G at the previous localization position receives the transmitted light of the other color filter 252 of Mg and G. Then, the sensor drive unit 40 inputs a drive pulse for scanning the electric charge accumulated in the position where the filter array 250 is localized at this position to the area image sensor 26, and thereby the image signal of the third color is supplied to each photosensitive unit 24. The area image sensor 26 outputs.

(Iv) Subsequently, the sensor drive unit 40 is shown in FIG.
As indicated by the arrow in (c), the filter array 250 is moved in the vertical direction by a distance corresponding to the arrangement pitch of the color filters 252 in the vertical direction, and then localized at the position shown in FIG. 7D. When the filter array 250 is present at this position, the color filters 2 adjacent to the upper side in the vertical direction of the color filter 252 assigned to each photosensitive section 24 when the filter array 250 was at the previous localization position.
52 is assigned. Therefore, at this position, the photosensitive portion 24 that receives the transmitted light of the Ye color filter 252 at the home position of the filter array 250 and the transmitted light of the Mg and G color filters 252 at the localization positions before and after the localization position of the filter array 250 is the Cy color unit. The transmitted light of the filter 252 is received, and the Mg color filter 25 is set at the home position.
When the transmitted light of 2 is received, Ye is detected two times before and at the previous localization position,
The photosensitive portion 24 that receives the transmitted light of the Cy color filter 252 receives the transmitted light of the G color filter 252.
Further, at this position, the light-receiving unit 24 receives the transmitted light of the G color filter 252 at the home position and the transmitted light of the Ye and Cy color filters 252 at the localization positions two before and at the previous localization position. Receiving light, Cy color filter 25 at home position
When the transmitted light of 2 is received, Mg is detected at the localization position two times before and the last time.
Photosensitive unit 2 that receives the transmitted light of G color filter 252
Reference numeral 4 receives the transmitted light of the Ye color filter 252.
Then, the sensor drive unit 40 inputs a drive pulse for scanning the electric charge accumulated in the position where the filter array 250 is localized at this position to the area image sensor 26, and thereby the image signal of the fourth color is supplied to each photosensitive unit 24. The area image sensor 26 outputs. (V) Subsequently, the sensor drive unit 40 moves the filter array 250 in the direction shown by the arrow in FIG.
Return to the home position shown in.

Next, the operation of the digital image processing section 60 in the fourth embodiment when the release switch 98 is fully pressed in the first image pickup mode will be described. When the sensor drive unit 40 operates in the first imaging mode, Ye, Mg,
The light transmitted through the color filters 252 for each of G and Cy is incident on each photosensitive section 24, and the image signals corresponding to each of Ye, Mg, G, and Cy colors are input from the AFE 52 to the digital image processing section 60 for each pixel. As a result, the digital image processing unit 60 operating in the first imaging mode does not perform interpolation using the image signals of neighboring pixels, and Ye, Mg,
Gradation values of all colors G and Cy or gradation values of a predetermined color acquired by color conversion processing based on those gradation values are obtained. Color image data is created as described above.

As described above, according to the digital camera of the fourth embodiment, the color information about each pixel in the color image data created in the first image pickup mode is directly obtained from the light received by each photosensitive section 24. Since the information of each color of Ye, Mg, G, and Cy is used, the color image data can more accurately represent the color information of the subject.

Next, the operation of the sensor drive section 40 and the digital image processing section 60 when the release switch 98 is fully pressed in the second image pickup mode in the fourth embodiment will be described. Sensor drive unit 40 operating in the second imaging mode
Is the area image sensor 26 with the filter array 250 localized at the home position shown in FIG.
By inputting a drive pulse for scanning the charges accumulated in the area image sensor 26, only one color image signal for each photosensitive portion 24 is supplied to the area image sensor 26.
To output from. However, the drive pulse for driving the area image sensor 26 is input according to the conventional field color difference sequential method, for example. When the sensor drive unit 40 operates in the second image pickup mode, Ye,
The transmitted light of the color filter 252 of any one of Mg, G, and Cy is incident on each photosensitive portion 24, and Ye, Mg, G, and Cy.
The image signal corresponding to any one of the colors is AFed for each pixel.
It is input to the digital image processing unit 60 from E52. The digital image processing unit 60, which operates in the second imaging mode, uses the input image signal to create color image data according to the conventional field color difference sequential method, for example.

As described above, according to the digital camera of the fourth embodiment, the area image sensor 2 is used in the second image pickup mode.
Since color image data can be created by only scanning the signal charges accumulated in 6 once per image pickup, it is possible to obtain color image data that accurately represents a still image of a subject moving at high speed.

In the fourth embodiment described above, Ye, M
The case where the configuration shown in FIG. 7 is adopted as the array configuration of the complementary color filters 252 for the four colors of g, G, and Cy has been described.
When using these four-color complementary color filters, for example, FIG. 8 shows a configuration in which the Mg and G color filters 252 are arranged in the same order as the first column in the horizontal direction in the horizontal direction in the third column of the above-described arrangement form. Array type filter array 30
Alternatively, a filter array (not shown) in which 0 or the color filters 252 of the same color are arranged in a vertical stripe shape, a horizontal stripe shape, or an oblique stripe shape may be adopted.

Although a plurality of embodiments of the present invention have been described above, this is merely an example, and the present invention should not be construed as limited by these embodiments. For example, in the above-described embodiments, the case where the color filters forming the color filter array are the primary color filters of three colors R, G, B or the complementary color filters of four colors Ye, Mg, G, Cy are described. , Other than them, for example, Ye,
Three complementary color filters of Mg and Cy, W (White), Y
You may use the complementary color filter of four colors of e, G, and Cy.

[Brief description of drawings]

FIG. 1 is a schematic view showing an operation of a color filter array according to a first embodiment of the present invention.

FIG. 2 is a sectional view schematically showing the internal structure of the digital camera according to the first embodiment of the present invention.

FIG. 3 is a schematic view showing an arrangement of color filters according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a digital camera according to an exemplary embodiment of the present invention.

FIG. 5 is a schematic view showing the operation of the color filter array according to the second embodiment of the present invention.

FIG. 6 is a schematic view showing the arrangement of color filters and the operation of the color filter array according to the third embodiment of the present invention.

FIG. 7 is a schematic diagram showing a configuration of a color filter array and an operation of the color filter array according to a fourth embodiment of the present invention.

FIG. 8 is a schematic diagram for explaining an arrangement of color filters different from the fourth embodiment of the present invention.

FIG. 9 is a schematic diagram showing an example of a conventional color filter array system.

[Explanation of symbols]

10 Digital camera 12 Optical system 20,252 color filter 22, 200, 250, 300 color filter array 24 Photosensitive area 26 area image sensor 28 actuators 30 Optical system drive 40 Sensor driver 50 processing unit 52 analog front end 60 Digital image processing unit 64 non-volatile memory 70 Control unit 90 Control 92 Mode selection switch 98 Release switch

Continued front page    F-term (reference) 2H048 BA02 BB02 BB07 BB46                 5C024 CY33 CY35 EX05 EX42 EX51                       HX23 HX57                 5C065 AA03 BB17 CC07 CC08 DD02                       DD17 EE05 EE06 EE07 GG18                       GG27

Claims (5)

[Claims] 1. A color filter array in which color filters of a plurality of colors are two-dimensionally arranged, and an area image sensor in which a plurality of photosensitive portions respectively receiving the transmitted light of the color filter are two-dimensionally arranged. A signal processing unit that creates color image data representing a subject based on an output signal of the area image sensor and stores the color image data in a recording medium; and a color processing unit that relatively moves the color filter array with respect to the area image sensor. A drive unit that allocates the color filters of all colors to each of them in a time division manner,
A digital camera comprising: 2. The drive unit relatively moves the color filter array with respect to the area image sensor in response to a selection operation by an operator, and time-divides the color filters of all colors in each of the plurality of photosensitive units. Or a second imaging mode in which the color filter of any one color is assigned to each of the plurality of photosensitive parts without moving the color filter array with respect to the area image sensor. The digital camera according to claim 1, wherein the digital camera is a digital camera. 3. The digital camera according to claim 1, wherein the color filters of the plurality of colors are arranged in stripes in the color filter array. 4. A color filter array in which color filters of a plurality of colors are arranged in a two-dimensional manner, and an area image sensor in which a plurality of photosensitive parts for respectively receiving transmitted light of the color filters are arranged in a two-dimensional manner, An image pickup method by a digital camera, comprising: a signal processing unit that creates color image data representing a subject based on an output signal of the area image sensor and stores the color image data in a recording medium. Is relatively moved, and the color filters of all colors are time-divided and assigned to each of the plurality of light-sensing units, and a subject is imaged. 5. A color filter array in which color filters of a plurality of colors are two-dimensionally arranged, and an area image sensor in which a plurality of photosensitive portions which respectively receive the transmitted light of the color filters are two-dimensionally arranged. An image pickup method using a digital camera, comprising: a signal processing unit that creates color image data representing a subject based on an output signal of the area image sensor and stores the color image data in a recording medium, the area image sensor according to a selection operation by an operator. With respect to the color filter array by moving the color filter array relative to each of the plurality of photosensitive units in a time division manner, or without moving the color filter array with respect to the area image sensor. By assigning one of the color filters to each of the plurality of light-sensing units, Imaging method of a digital camera, characterized in that the image.