JP3615441B2 - Digital camera - Google Patents

Description

[0001]
[Industrial application fields]
This invention is a digital camera.LaIn particular, for example, a digital camera that reads a charge from a light receiving element of a CCD imager to generate a low resolution camera signal.LaRelated.
[0002]
[Prior art]
In the conventional digital camera of this type, when the charge is thinned out from the CCD imager and read out, the read out charges are individually transferred and output individually from the CCD imager.
[0003]
[Problems to be solved by the invention]
However, charge thinning out is equivalent to charge sampling, and according to the sampling theorem, the output camera signal includes a folding component. In order to remove such aliasing components, a filter may be provided, but in that case, the cost is increased by the amount of the added filter.
[0004]
Therefore, a main object of the present invention is to provide a digital camera that can prevent noise generation at low cost.
[0006]
[Means for Solving the Problems]
A digital camera according to the present invention includes a color filter formed by a plurality of color elements in which N (N: an integer of 2 or more) colors are distributed, an imager having a plurality of light receiving elements respectively corresponding to the plurality of color elements, At least part of the plurality of light receiving elements, a determining means for determining the exposure period of the imager by evaluating the brightness of the field, a sweeping means for sweeping out the charges generated by the plurality of light receiving elements at the start timing of the exposure period, and Read means for reading the generated charges after the exposure period has elapsed, and change means for changing the read method of the read means between the first method and the second method according to the exposure period, and the plurality of light receiving elements is N A plurality of first light receiving elements respectively corresponding to a plurality of first color elements in which a plurality of colors are distributed and a plurality of second light elements corresponding to a plurality of second color elements in which N colors are distributed. The first method is a method of reading out only the first charges generated by the plurality of first light receiving elements, and the second method is to read out the first charges at the first timing, and the plurality of second light receiving elements. The second charge generated in step 1 is read at a second timing and the first charge and the second charge corresponding to the color elements of the same color are mixed with each other, and the changing means is the first method when the exposure period is equal to or less than the threshold value. And the second method is activated when the exposure period is longer than the threshold value.
[0008]
[Action]
The color filter is formed by a plurality of color elements in which N (N: an integer of 2 or more) colors are distributed, and the imager has a plurality of light receiving elements respectively corresponding to the plurality of color elements. The determining means evaluates the brightness of the object scene and determines the exposure period of the imager. The charges generated by the plurality of light receiving elements are swept away by the sweeping means at the start timing of the exposure period, and the charges generated by at least a part of the plurality of light receiving elements are read by the reading means after the exposure period has elapsed. . The changing unit changes the reading method of the reading unit between the first method and the second method according to the exposure period.
Here, the plurality of light receiving elements respectively correspond to the plurality of first light receiving elements corresponding to the plurality of first color elements in which N colors are distributed and the plurality of second color elements in which N colors are distributed. A plurality of second light receiving elements. The first method is a method of reading only the first charges generated by the plurality of first light receiving elements. Further, in the second method, the first charge is read at the first timing, the second charges generated by the plurality of second light receiving elements are read at the second timing, and the first charge and the second corresponding to the color element of the same color are read. In this method, electric charges are mixed with each other. The changing unit validates the first method when the exposure period is equal to or less than the threshold, and validates the second method when the exposure period is longer than the threshold.
[0009]
Preferably, the imager has a vertical transfer register. The first charge reading means reads the first charge to the vertical transfer register, and the second read means vertically transfers the second charge when the first charge read to the vertical transfer register is subjected to vertical transfer of a predetermined distance. Read to transfer register.
[0010]
More preferably, the changing unit changes the reading method by enabling / disabling the second charge reading unit.
[0011]
Preferably, the vertical transfer register is formed of a plurality of metals, and at least three metals are assigned to one light receiving element.
[0012]
The color filter is preferably a filter in which primary color elements are arranged in a Bayer array.
[0017]
[0018]
The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.
[0019]
【Example】
Referring to FIG. 1, a digital camera 10 of this embodiment includes a lens 12. The light image incident from the lens 12 passes through the aperture unit 16 and is irradiated to the interline transfer type CCD imager 20 provided in the imaging device 14. A plurality of light receiving elements 20 a are formed in the CCD imager 20 as shown in FIG. 2, and each light receiving element 20 a constitutes each pixel of the CCD imager 20. As shown in FIG. 3, a primary color filter 20d in which R, G, and B color elements are Bayer-arranged is mounted on the front surface of the light receiving element 20a. Any one of R, G, and B color elements is attached to each light receiving element 20a. Corresponds to. That is, one color element corresponds to one light receiving element. The subject image is irradiated to the light receiving element 20a through the primary color filter 20d and subjected to photoelectric conversion.
[0020]
Here, when the primary color filter 20a is considered as a collection of color blocks of 2 lines × 2 pixels, G color elements are arranged on one diagonal line of the color block, and R and B colors are arranged on the other diagonal line. The element is placed. A plurality of such color blocks exist on the primary color filter 20a, and each color block is adjacent to each other in both the vertical direction and the horizontal direction. Further, when attention is paid to the vertical column forming the primary color filter 20a, the R color element and the G color element are alternately arranged for each pixel in a certain vertical column, and the G color element and B in another vertical column. Color elements are alternately arranged for each pixel. That is, in any vertical column, two color elements are alternately arranged for each pixel.
[0021]
Referring back to FIG. 2, the CCD imager 20 includes a plurality of light receiving elements 20a corresponding to each pixel, a plurality of vertical transfer registers 20b that transfer photoelectrically converted and accumulated charges in the light receiving elements 20a in the vertical direction, and a vertical transfer register 20b. It includes a horizontal transfer register 20c that is disposed at the end of the transfer register 20b and transfers the charges transferred by the vertical transfer register 20b in the horizontal direction, and is driven by a drive pulse output from a timing generator (TG) 22. Here, as the drive pulse, a read pulse for reading out charges from the light receiving element 20a to the vertical transfer register 20b, a vertical transfer pulse for transferring the read charges in the vertical direction line by line, and a charge in the horizontal transfer register 20c of 1 are used. There are a horizontal transfer pulse for transferring pixel by pixel in the horizontal direction, a sweep pulse for sweeping charges generated by the light receiving element 20a to an overflow drain (not shown) during a non-exposure time, that is, a non-charge accumulation period.
[0022]
When the camera mode is set by the mode setting button 46 and the release button 48 is pressed, pre-exposure is performed first, and the charge obtained thereby is read from the CCD imager 20. At the time of pre-exposure, the TG 22 controls the output period of the sweep pulse according to the initial shutter speed data set by the microcomputer 40. As shown in FIG. 4, the sweep-out period starts from the beginning of one frame period of interest, and the end time of the sweep-out period is controlled by the shutter speed data. In this way, the charge accumulation period changes, and exposure with a desired shutter speed (exposure time) is realized. A method for controlling the shutter speed according to the output period of the sweep-out pulse is well known as an electronic shutter function.
[0023]
The pixel signal (camera signal) output from the CCD imager 20 is converted into a digital signal, that is, pixel data by the A / D converter 24, and this pixel data is written into the RAM 26 by the writing / reading control circuit 28. Pixel data stored in the RAM 26 is read by the same writing / reading control circuit 28 and input to the arithmetic circuit 30.
[0024]
The input pixel data has only one color component of R, G, and G. The arithmetic circuit 30 performs color interpolation and YUV conversion on such pixel data to generate Y data, U data, and V data. Among these, the Y data is input to the weighting circuit 32. The weighting circuit 32 multiplies the Y data by the weighting amount held in the weighting amount table 34. The weight amount table 34 receives read address data from the write / read control circuit 28 and outputs a corresponding weight amount. By applying a weighting process to the Y data with this weighting amount, center-weighted photometry can be performed. The Y data output from the weighting circuit 32 is integrated every frame period by the integrator 36. The computing unit 38 divides the integral data output from the integrator 36 by the sum of the weights, and calculates a luminance evaluation value that is an evaluation target for exposure adjustment. The U data and V data calculated together with the Y data by the computing unit 30 are given to a white balance adjustment circuit (not shown).
[0025]
The microcomputer 40 takes in the luminance evaluation value output from the computing unit 38 and updates the shutter speed based on the luminance evaluation value. When the optimum shutter speed (optimum exposure period) is calculated, the microcomputer 40 performs the main exposure. The camera signal generated by the main exposure is given to the signal processing circuit 42 via the switch SW1. Then, the image signal that has undergone predetermined signal processing is recorded on the recording medium 44.
[0026]
The microcomputer 40 sets one of the thinning readout method and the pixel mixture readout method in the TG 22 according to the value of the optimum shutter speed. When attention is paid to four pixels that are continuous in the vertical direction, in the thinning-out readout method, electric charges are read from predetermined two pixels among the four pixels. On the other hand, in the pixel mixture readout method, charges are read from all four pixels, and pixels having the same color component are mixed. Therefore, no matter which method is set, the number of pixels constituting the camera signal is the same.
[0027]
Each readout method will be described in detail with reference to pixels that are continuous in the vertical direction as shown in FIGS. 5A, 5B, 6A, and 6B. The vertical transfer register 20b is formed by a plurality of metals (electrodes) M, and three metals M are allocated to one light receiving element 20a (pixel). Since the color filter 20d is a primary color filter in which R, G, and B are arranged in a Bayer array, R pixels and G pixels are alternately formed in each odd-numbered vertical column (odd column), and even-numbered vertical columns are formed. In the columns (even columns), G pixels and B pixels are alternately formed for each pixel. Looking at the three metals M assigned to each pixel, the V1 pulse is applied to the top metal M, the V3 pulse is applied to the center metal M, and the V2A or V2B pulse is the bottom metal. Applied to M. The application destination of the V2A pulse and the application destination of the V2B pulse are switched every two pixels. That is, when the V2A pulse is given to the first half R pixel and G pixel among the R pixel, G pixel, R pixel, and G pixel that are consecutive in the odd-numbered columns, the V2B pulse is given to the second half R pixel and G pixel. Even in the even-numbered column, when the V2A pulse is given to the G pixel and the B pixel in the first half of the four consecutive pixels, the V2B pulse is given to the latter G pixel and the B pixel.
[0028]
In this way, in the CCD imager 20 in which three metals M are assigned to each light receiving element 20a, each pixel can be progressively scanned. This means that even when charges are read from all the light receiving elements 20a simultaneously, the charges read from the adjacent light receiving elements 20a are individually transferred. That is, even when all pixels are read out, the R signal, G signal, and B signal obtained from each pixel are output from the CCD imager 20 without being mixed with each other.
[0029]
Referring to FIGS. 5A and 5B, when the thinning readout method is selected, reading of charges from the pixel to which the V2B pulse is applied is stopped, and only from the pixel to which the V2A pulse is applied. The charge is read out. For this reason, the charges for two pixels continuous in the vertical direction are read out every two pixels. In the odd columns, the R4 signal, the G4 signal, the R2 signal, and the G2 signal are read and individually transferred on the corresponding vertical transfer register 20b. On the other hand, the G4 signal, the B4 signal, the G2 signal, and the B2 signal are read out in the even-numbered columns and are also individually transferred on the corresponding vertical transfer registers 20b. That is, when the thinning readout method is selected, the color block that is the target of reading is a color block that exists every other block in the vertical direction. The pixel signals transferred in the vertical direction are then subjected to horizontal transfer for each line. The camera signal output from the CCD imager 20 includes all R, G, and B color components.
[0030]
Referring to FIGS. 6A and 6B, when the pixel mixed readout method is selected, charges are read from all pixels. However, first, charge is read from the pixel to which the V2A pulse is applied, and when the read charge is transferred by two pixels in the vertical direction, the charge is read from the pixel to which the V2B pulse is applied. In the odd-numbered column, first, the R4 signal, the G4 signal, the R2 signal, and the G2 signal are read to the vertical transfer register 20b and individually transferred on the vertical transfer register 20b. When the vertical transfer for two lines is completed, the R3 signal, the G3 signal, the R1 signal, and the G1 signal are read out. As a result, charges corresponding to the same color element are mixed on the vertical transfer register 20b, and (R3 + R4) signal, (G3 + G4) signal, (R1 + R2) signal and (G1 + G2) signal are obtained. In the even-numbered column, first, the G4 signal, the B4 signal, the G2 signal, and the B2 signal are read to the vertical transfer register 20b, and when these signals are vertically transferred by two lines, the G3 signal, the B3 signal, the G1 signal, and The B1 signal is read to the same vertical transfer register 20b. As a result, a (G3 + G4) signal, a (B3 + B4) signal, a (G1 + G2) signal, and a (B1 + B2) signal are generated on the vertical transfer register 20b.
[0031]
In other words, when the pixel mixture readout method is selected, first, pixel signals are read out from the color blocks existing every other block in the vertical direction. Then, when this pixel signal is transferred for two lines in the vertical direction, the pixel signal is read from the remaining color blocks. As a result, pixel signals having the same color components are mixed on the vertical transfer register 20b. The mixed pixel signal is vertically transferred so as not to be mixed between different color components, and then horizontally transferred for each line. That is, a camera signal including all R, G, and B color components is output from the CCD imager 20.
[0032]
In the thinning readout method, the aliasing component is included in the camera signal according to the sampling theorem. For this reason, noise appears unless the aliasing component is removed from the camera signal by filtering. On the other hand, in the pixel mixture readout method, when one pixel signal is vertically transferred by two lines, the other pixel signal is read and the pixel signals are mixed. Such a transfer method is equivalent to the filter processing shown in FIG. That is, when attention is paid to the R1 signal and the R2 signal, the R1 signal is read after being delayed from the R2 signal, and both are added. When the pixel mixed readout method is selected, the filtering process is executed in this way, and the aliasing component is removed from the camera signal.
[0033]
The TG 22 that performs charge transfer is configured as shown in FIG. The H counter 22a is a counter that counts the number of horizontal pixels. The horizontal count value is reset in response to a shooting instruction from the microcomputer 40 or a horizontal synchronization signal, and incremented in response to a pixel clock. On the other hand, the V counter 22b is a counter that counts the number of vertical lines. The vertical count value is reset in response to an imaging instruction or a vertical synchronization signal, and incremented in response to a horizontal synchronization signal. Both the horizontal count value and the vertical count value are given to the decoders 22c to 22k. The decoder 22c generates a charge sweeping pulse SUB based on these count values and the shutter speed data from the microcomputer 40. The decoder 22d generates a horizontal transfer pulse H1 (H1 pulse) from the input count value, and the decoders 22e and 22f generate a vertical transfer pulse V1 (V1 pulse) and a vertical transfer pulse V3 (V3 pulse) from the count value. Is generated.
[0034]
Further, the decoders 22g to 22k generate timing pulses XV2A, XSGA, XV2B1, XV2B2, and XSGB, respectively. Among these, the timing pulses XV2A and XSGA are supplied to the driver 22m as they are. On the other hand, the timing pulses XV2B1 and XV2B2 are applied to the driver 22m via the switch SW2, and the timing pulse XSGB is directly applied to the driver 22m. The microcomputer 40 connects the switch SW2 to the decoder 22i side when the thinning readout method is selected, and connects the switch SW2 to the decoder 22j side when the pixel mixed readout method is selected. For this reason, the timing pulse XV2B1 is input to the driver 22n at the time of thinning readout, and the timing pulse XV2B2 is input to the driver 22n at the time of pixel mixture readout. The drivers 22m and 22n respectively generate a vertical transfer pulse V2A (V2A pulse) and a vertical transfer pulse V2B (V2B pulse) based on the applied timing pulse.
[0035]
Therefore, as can be seen from FIGS. 9 and 12, the H1 pulse, V1 pulse, V2A pulse, and V3 pulse are common to each readout method, but the V2B pulse differs depending on the readout method. At the time of thinning readout, only the V2A pulse has a positive polarity in the A period, and as a result, charges are read only from the pixels to which the V2A pulse is applied. That is, the process of reading out charges from the pixel to which the V2B pulse is applied is disabled. On the other hand, at the time of pixel mixed readout, the V2A pulse first takes positive polarity in the same A period, and then the V2B pulse takes positive polarity. For this reason, after the charge is read from the pixel to which the V2A pulse is applied, the charge is read from the pixel to which the V2B pulse is applied. In the V2A pulse and the V2B pulse, a portion having a positive polarity corresponds to a read pulse.
[0036]
When the thinning readout method is selected, each pulse changes as shown in FIG. When the V2A pulse becomes a positive level, the charge of the corresponding pixel is read out to the vertical transfer register. After reading, the V2A pulse and the V2B pulse simultaneously take a negative level twice, whereby the charge is transferred in the vertical direction by two lines. As can be seen from FIG. 11, the V2A pulse and the V2B pulse are at a negative level at a predetermined timing other than the A period, and the V1 pulse and the V3 pulse are at a negative level at substantially the same timing. As a result, charges are transferred in the vertical direction. The vertically transferred charges are then horizontally transferred by the H1 pulse and output from the CCD imager 20.
[0037]
In the period A when the pixel mixture readout method is selected, each pulse changes as shown in FIG. The V2A pulse takes the positive level once, and then the V2A pulse and the V2B pulse take the negative level twice at the same time. As a result, the first read charge is vertically transferred by two lines. Subsequently, the V2B pulse takes a positive level once, and the charge read in response to this is mixed with the charge transferred vertically. During periods other than the A period, each pulse changes as shown in FIG. 14, whereby the mixed charges are transferred in the vertical direction. The mixed charge is horizontally transferred by the H1 pulse after the vertical transfer.
[0038]
The microcomputer 40 processes the flowcharts shown in FIGS. 15 and 16 to calculate the main exposure amount, and records the photographed subject image on the recording medium 44. Note that the processing in this flowchart is started in response to pressing of the release button 48.
[0039]
First, the aperture is set to a predetermined F value in step S1, and the exposure time (shutter speed) is initialized in step S3. That is, for example, initial shutter speed data of 1/250 seconds is set in TG22. In step S4, the switch SW2 is switched to the decoder 22i side to set the thinning readout method to TG22. In step S5, the TG 22 is instructed to perform photographing. The TG 22 performs pre-exposure according to the set shutter speed data, and reads out the generated charges by a thinning readout method.
[0040]
The microcomputer 40 fetches the luminance evaluation value output from the calculator 38 based on the camera signal obtained by the pre-exposure in step S7, and calculates the next shutter speed in step S9. Specifically, the brightness evaluation value is compared with a target evaluation value obtained in an optimal exposure state, and a shutter speed at which the luminance evaluation value matches the target evaluation value is calculated. For example, if the luminance evaluation value is “50” and the target evaluation value is “100”, the luminance is only half of the optimum state, so the next exposure time is 1/125 seconds. The microcomputer 40 updates the shutter speed data set in the TG 22 in step S11, and determines whether or not the processes in steps S5 to S11 have been executed three times in step S13. That is, the above process is repeated three times in order to accurately calculate the shutter speed (optimum shutter speed) at which a desired exposure amount can be obtained.
[0041]
If "YES" is determined in the step S13, the microcomputer 40 compares the optimum shutter speed (optimum exposure period) with the time data of 1/1000 second in a step S15. If the optimum exposure period is longer than 1/1000 second or 1/1000 second, the switch SW2 is switched to the decoder 22j side in step S17 to set the pixel mixed readout method. Then, the process proceeds to step S19. On the other hand, if the optimum exposure period is shorter than 1/1000 second, the process proceeds to step S19 while maintaining the thinning readout method. Therefore, if the optimum exposure period is 1/500 seconds, for example, the pixel mixed readout method is selected.
[0042]
Since the electronic shutter shown in FIG. 4 is used for the shutter control of this embodiment, necessary charges are accumulated after sweeping out unnecessary charges, and the charges are read when a predetermined accumulation period has elapsed. Then, in the pixel mixture readout method in which the pixels are read out at different times, the influence of the deviation in the readout time increases as the shutter speed increases. That is, the difference between the amount of charge read out first and the amount of charge read out later increases as the exposure time decreases. For this reason, in this embodiment, the charge readout method is switched in accordance with the value of the optimum shutter speed. On the other hand, the reason why the switching threshold is set to 1/1000 second is that it takes the same 1/1000 second to transfer the read charge for one line.
[0043]
Thereafter, the microcomputer 40 instructs the TG 22 to shoot in step S19. For this reason, the main exposure is executed at the optimum shutter speed, and the electric charges generated thereby are read out in a desired manner. When the camera signal is output from the CCD imager 20 in this way, the microcomputer 40 performs a recording process in step S21. The camera signal is input to the signal processing circuit 42 via the switch SW1 and subjected to predetermined processing. The still image signal output from the signal processing circuit 42 is recorded on the recording medium 44.
[0044]
According to this embodiment, the filter processing as shown in FIG. 14 is performed in the CCD imager 20 by selecting the pixel mixed readout method, so that the aliasing component is removed from the camera signal without adding a filter circuit. be able to. In addition, since the pixel mixture readout method is selected only when the optimum shutter speed is low, the amount of charge does not deviate greatly between the charge read first and the charge read second.
[0045]
In this embodiment, the aperture priority mode has been described. However, the present invention can also be applied to the shutter speed priority mode and the program AE mode. In the shutter speed priority mode, the exposure amount changes by adjusting the aperture amount. In the program AE mode, the exposure amount changes by adjusting both the shutter speed and the aperture amount. Therefore, if the shutter speed that can be set in the shutter speed priority mode is limited to a speed lower than 1/1000 seconds, a camera signal that does not include the aliasing component can always be obtained.
[0046]
In this embodiment, only the case of taking a still image has been described. Needless to say, the present invention can also be applied to moving image shooting. The present invention can also be applied to a through image mode in which a real-time moving image (through image) is displayed on a liquid crystal display.
[0047]
Further, in this embodiment, the shutter speed is controlled by the electronic shutter, but the shutter speed may be controlled by a so-called mechanical shutter at the time of shooting a still image. In this embodiment, the thinning readout method is set at the time of pre-exposure, but it goes without saying that a pixel mixed readout method may be set instead. Furthermore, in this embodiment, primary color filters in which R, G, and B color elements are arranged in a Bayer array are used. However, complementary color filters having Ye, Cy, Mg, and G color elements as shown in FIG. It may be used instead of the primary color filter.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 2 is an illustrative view showing a CCD imager.
FIG. 3 is an illustrative view showing a primary color filter;
4 is an illustrative view showing one portion of operation of FIG. 1 embodiment; FIG.
FIG. 5 is an illustrative view showing one portion of an operation in a thinning readout mode;
FIG. 6 is an illustrative view showing a part of the operation in the pixel mixed readout mode;
FIG. 7 is a block diagram illustrating an example of a filter.
FIG. 8 is a block diagram illustrating an example of a TG.
FIG. 9 is a timing chart showing a part of the operation in the thinning readout mode.
FIG. 10 is a timing chart showing another part of the operation in the thinning readout mode.
FIG. 11 is a timing chart showing another part of the operation in the thinning readout mode.
FIG. 12 is a timing chart showing a part of the operation in the pixel mixed readout mode.
FIG. 13 is a timing chart showing another part of the operation in the pixel mixture readout mode.
FIG. 14 is a timing chart showing another part of the operation in the pixel mixture readout mode.
FIG. 15 is a flowchart showing a part of the operation of FIG. 1 embodiment;
16 is a flowchart showing another portion of the operation of the embodiment in FIG. 1; FIG.
FIG. 17 is an illustrative view showing a complementary color filter;
[Explanation of symbols]
10. Digital camera
14 ... Imaging device
20 ... CCD imager
22 Timing generator
40 ... Microcomputer

Claims (5)

A color filter formed by a plurality of color elements in which N (N: an integer of 2 or more) colors are distributed;
An imager having a plurality of light receiving elements respectively corresponding to the plurality of color elements;
Determining means for evaluating the brightness of the field and determining the exposure period of the imager;
A sweeping means for sweeping out the charges generated by the plurality of light receiving elements at the start timing of the exposure period;
A reading means for reading out charges generated in at least a part of the plurality of light receiving elements after the exposure period; and
Changing means for changing the reading method of the reading means between the first method and the second method according to the exposure period;
The plurality of light receiving elements respectively correspond to a plurality of first light receiving elements corresponding to a plurality of first color elements in which N colors are distributed, and a plurality of second color elements in which the N colors are distributed. Including a plurality of second light receiving elements;
The first method is a method of reading only the first charges generated by the plurality of first light receiving elements,
In the second method, the first charge is read at a first timing, the second charges generated by the plurality of second light receiving elements are read at a second timing, and the first charge corresponding to the same color element and the first charge Is a method of mixing two charges with each other,
The change means is a digital camera that activates the first method when the exposure period is less than or equal to a threshold value, and validates the second method when the exposure period is longer than the threshold value . The imager has a vertical transfer register;
The reading means is a first charge reading means for reading the first charge to the vertical transfer register, and the first charge read to the vertical transfer register is subjected to vertical transfer for a predetermined distance. 2. The digital camera according to claim 1 , further comprising second charge reading means for reading two charges into the vertical transfer register . The digital camera according to claim 2, wherein the changing unit changes the reading method by enabling / disabling the second charge reading unit . 4. The digital camera according to claim 2 , wherein the vertical transfer register is formed of a plurality of metals, and at least three metals are assigned to one light receiving element . 5. The digital camera according to claim 1, wherein the color filter is a filter in which color elements of primary colors are arranged in a Bayer array .

Images