JP2004236028A - Solid-state image pickup apparatus, camera and camera system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state image pickup apparatus which eliminates the need for accelerating a color selection switch of an external circuit and is little in color mixture caused by pixel signals which have different colors and are temporally adjacent to each other. <P>SOLUTION: This solid-state image pickup apparatus is provided with: an imaging part wherein a plurality of unit pixels 1 for photoelectrically converting incident light are arrayed two-dimensionally so as to include a plurality of types of rows with different color arrangement; a plurality of output signal lines from which the pixel signals of the imaging part are read; and a plurality of output parts for outputting signals of the output signal lines. Pixel signals obtained from a plurality of unadjacent pixels of a first color in a first row are sequentially and continuously outputted from a first outputting part 7a, and pixel signals obtained from a plurality of unadjacent pixels of a second color different from the first color in the first row are sequentially and continuously outputted from a second outputting part 7b. Thereafter, pixel signals of a plurality of unadjacent pixels of the first color in a second row are sequentially and continuously read out to a first output signal line 6a when the pixel signals of the second row whose color arrangement is different from that of the first row are read. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a solid-state imaging device in which unit pixels for photoelectrically converting incident light are two-dimensionally arranged, and a camera such as a digital still camera and a moving image camera or a camera system using the same.
[0002]
[Prior art]
In a solid-state imaging device used in a conventional digital still camera or the like, a pixel signal obtained from each pixel for photoelectric conversion is transferred to a storage unit for each row, for example, and stored, and then output from a horizontal shift register. The pixel signals for each row are sequentially output in synchronization with the read pulse (for example, see Patent Document 1).
[0003]
FIG. 3 shows a configuration of a conventional MOS type solid-state imaging device 8 (only a part is shown) and an external circuit 9. The solid-state imaging device 8 includes a pixel 1 arranged two-dimensionally, a vertical shift register 2 for selecting a pixel in a column direction, a vertical signal line 3 in a column direction, and a row memory unit 4 for accumulating signals of each row. , A horizontal shift register 5 for selecting the row memory unit 4, a readout switch 51 driven by the output of the horizontal shift register 5, an output signal line 6 for outputting a pixel signal for each row, and an output amplifier 7 It consists of. The external circuit 9 includes an external memory 10 that accumulates pixel signals output from the solid-state imaging device 8 for each color, and a color selection switch 11.
[0004]
This solid-state imaging device 8 is a Bayer array of pixels 1 of three primary colors of red (R), green (G), and blue (B). The signals of the pixels 1 in each row are read out to the vertical signal lines 3 for each row by the vertical shift register 2, and then transferred to the row memory unit 4. Pixel signals in the row memory unit 4 are sequentially transferred to the output signal line 6 via the readout switch 51 in the order of readout pulses S1 to S6 output from the horizontal shift register 5 and output from the output amplifier 7. . The output signal from the output amplifier 7 is input to the external circuit 9, is switched for each color by the color selection switch 11, is stored in the external memory 10, and is subjected to image processing.
[0005]
[Patent Document 1]
JP 2001-45378 A (FIGS. 13 and 14)
[0006]
[Problems to be solved by the invention]
FIG. 4 shows an output waveform from the output amplifier 7 of the MOS solid-state imaging device 1. As shown in FIG. 4A, the pixel signals in the n-th row are G1 (n), B1 (n), G2 (n) when the readout pulses S1 to S6 from the horizontal signal transmission circuit 5 are sequentially turned on. ), B2 (n), G3 (n) and B3 (n) in this order. As shown in FIG. 4B, the pixel signals in the (n + 1) th row are arranged in the order of R1 (n + 1), G1 (n + 1), R2 (n + 1), G2 (n + 1), R3 (n + 1), G3 (n + 1). Output from the amplifier 7. At that time, in the output signal of the output amplifier 7, pixel signals of different colors are adjacent. Therefore, in the external circuit 9, it is necessary to select the output signal for each color at high speed by the color selection switch 11 and transfer the output signal to the external memory 10 for each color. In the case of the configuration shown in FIG. 3, in order to transfer one row of image signals to the external memory 10, for example, it is necessary to switch the two color selection switches 11 12 times for pixel signals of n rows and n + 1 rows.
[0007]
In addition, since the output signal is easily affected by an adjacent signal in time, color mixing may occur and image quality is deteriorated. In particular, when the signal output speed is increased, it is necessary to increase the speed of the color selection switch of the external circuit and prevent color mixing.
[0008]
The present invention has been made in view of the above-described problems, and provides a solid-state imaging device that does not require high-speed color selection switches of an external circuit even when signal output is speeded up, and reduces color mixing. Aim.
[0009]
[Means for Solving the Problems]
A solid-state imaging device according to an aspect of the invention includes an imaging unit in which a plurality of unit pixels that photoelectrically convert incident light are two-dimensionally arranged so as to include a plurality of types of rows having different color arrangements. An output signal line to be read out and an output unit to output a signal of the output signal line are provided.
[0010]
In order to solve the above-mentioned problem, a plurality of sets of the output signal lines and output units are provided, and pixel signals obtained from a plurality of non-adjacent pixels of a first color in a first row are sequentially and continuously output to a first output terminal. Output from the output unit, and sequentially and continuously output pixel signals obtained from a plurality of non-adjacent pixels of a second color different from the first color in the first row from the second output unit. When reading out the pixel signals in the second row having a different color arrangement from the first row, if the second row includes the pixel of the first color, Pixel signals of a plurality of non-adjacent pixels of the first color are sequentially and sequentially read to the first output signal line.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
According to the solid-state imaging device of the present invention having the above-described configuration, different colors can be read in parallel from different output units in the same row of the solid-state imaging device, and the speed of signal reading can be increased. Even when the color arrangement is different for each row, if the same color is present in consecutive rows, the same color can be read from the same output unit, so that the color selection switch of the external circuit can be switched at a low speed. It can easily cope with high-speed signal output. In addition, since the same color continues in the output signal for a certain period of time, it is possible to reduce the color mixture of the output signal and realize high image quality.
[0012]
The configuration for reading out the pixel signals may be as follows. That is, when a plurality of sets of the output signal lines and the output units are provided, and when reading out the signal of each pixel in the first row, if the row includes pixels of a plurality of colors, the first row Are sequentially output from the output units that are different for each color, and then, when a second row having a different arrangement from the first row is read, the pixels in the first row are included in the second row. Is included, a pixel signal of at least one pixel of the specific color in the second row is converted to a pixel signal of a pixel of the color in the first row. Is read out to the output signal line from which is read out.
[0013]
In the above configuration, a configuration in which pixel signals of pixels of different colors in the same row are respectively read out to the different output signal lines by only one at a time, and then output from the output unit connected to each output signal line. You can also.
[0014]
Further, instead of the above-described configuration in which data is read out to the output signal line for each row, a configuration in which data is read out to the output signal line for each column can be used as follows.
[0015]
In that case, the solid-state imaging device of the present invention includes an imaging unit in which a plurality of unit pixels that photoelectrically convert incident light are two-dimensionally arranged to include a plurality of types of columns having different color arrangements, An output signal line from which a pixel signal is read out, and an output unit to which a signal of the output signal line is output.
[0016]
And a plurality of sets of the output signal line and the output unit, and sequentially and continuously output pixel signals obtained from a plurality of non-adjacent pixels of the first color in the first column from the first output unit; Pixel signals obtained from a plurality of non-adjacent pixels of a second color different from the first color in the first column are sequentially and continuously output from the second output unit, and thereafter, the first column is output. When reading out the pixel signals in the second column having a different color arrangement from the first column, if the pixel of the first color is included in the second column, the first color in the second column is read out. , The pixel signals of a plurality of non-adjacent pixels are sequentially read out to the first output signal line.
[0017]
The configuration for reading out the pixel signals may be as follows. That is, when a plurality of sets of the output signal lines and the output units are provided, and a signal of each pixel in the first column is read, if the column includes pixels of a plurality of colors, the first column Are sequentially output from the output units that are different for each color, and then when a second column that is different in arrangement from the first column is read, the first column is included in the second column. If a pixel of a specific color matching the color of the pixel is included, the pixel signal of at least one pixel of the specific color in the second column is converted to a pixel signal of the color in the first column. Is read out to the output signal line from which the pixel signal has been read out.
[0018]
In the above configuration, a configuration is such that pixel signals of pixels of different colors in the same column are simultaneously read out to the different output signal lines by only one each, and then output from the output unit connected to each output signal line. I do.
[0019]
A camera or camera system can be configured by mounting the solid-state imaging device having any of the above configurations.
[0020]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0021]
FIG. 1 shows a configuration of a MOS solid-state imaging device 12 and an external circuit 13 according to an embodiment of the present invention. The same elements as those of the conventional apparatus shown in FIG. 3 are denoted by the same reference numerals to avoid duplication of description.
[0022]
The configuration of the solid-state imaging device 12 different from the conventional device of FIG. 3 is that it has two output signal lines 6a and 6b. Output amplifiers 7a and 7b are connected to the output signal lines 6a and 6b, respectively. Read switches 5a and 5b are inserted between the row memory unit 4 and the output signal lines 6a and 6b. Further, in the external circuit 13, the color selection switches 11a to 11c are connected by sections corresponding to the output signals of the output amplifiers 7a and 7b.
[0023]
As in the conventional example, three primary colors of red (R), green (G), and blue (B) are arranged in the pixel 1 in a Bayer array. The pixel signals stored in the row memory unit 4 are distributed to and read out from the two output signal lines 6a and 6b, respectively. Therefore, the row memory unit 4 is connected to the output signal line 6a via the readout switch 5a, and is connected to the output signal line 6b via the readout switch 5b. The read pulses S1 to S6 output from the horizontal shift register 5 are supplied for each pair of the adjacent read switches 5a and 5b.
[0024]
In the present embodiment, the operation of reading the signal of the pixel 1 in each row to the output signal lines 6a and 6b is as follows. Pixel signals of a certain row are read out to the vertical signal line 3 by the vertical shift register 2 and transferred to the row memory unit 4. Thereafter, the read pulses S1 to S3 are sequentially supplied from the horizontal shift register 5 to each pair of the read switches 5a and 5b. However, pairs of the read switches 5a and 5b to which the read pulses S2 and S3 are supplied are selected every other pair as shown in FIG. For each of the read pulses S1 to S3, pixel signals of adjacent different colors in the same row stored in the row memory unit 4 are simultaneously read to the output signal lines 6a and 6b. Therefore, pixel signals of the same color are read out to the output signal lines 6a and 6b for each of the readout pulses S1 to S3.
[0025]
Subsequently, the pixel signal of the next row is read out to the vertical signal line 3 by the vertical shift register 2 and transferred to the row memory unit 4. Thereafter, the read pulses S4 to S6 are sequentially supplied from the horizontal shift register 5 to the pair of read switches 5a and 5b. For each of the readout pulses S4 to S6, pixel signals of adjacent different colors in the same row stored in the row memory unit 4 are simultaneously read out to the output signal lines 6a and 6b, respectively. However, in this case, the read pulses S4 to S6 are supplied to the pair of the read switches 5a and 5b to which the read pulses S1 to S3 have not been supplied. Therefore, the correspondence between the storage position in the row memory unit 4 and the output signal lines 6a and 6b is reversed. As a result, all signals of the pixels 1 of the same color (G) arranged in two adjacent rows are read out to the output signal line 6a.
[0026]
For example, in the case of the pixel arrangement shown in FIG. 1, after the signal of the n-th row is transferred to the row memory unit 4, the signal of the green (G) pixel 1 is output to the output signal line 6a by the read pulses S1, S2 and S3. However, a blue (B) pixel 1 signal is read out to the output signal line 6b. Next, after transferring the signal of the (n + 1) th row to the row memory unit 4, the read pulse S4, S5, and S6 cause the signal of the green (G) pixel 1 to be output to the output signal line 6a and the output signal line 6b to be output. The signal of the red (R) pixel 1 is read. Therefore, green (G) is always read out to the output signal line 6a, and green (G) is always output from the output amplifier 7a. On the output signal line 6b, blue (B) is read in a certain row, and red (R) is read in the next row. Blue (B) and red (R) are alternately output to the output amplifier 7b for each row. Is output to
[0027]
Output signals of the output amplifiers 7a and 7b are input to the external circuit 13, and are stored in the external memory 10 for each color by the color selection switches 11a, 11b and 11c. In the present embodiment, in the case of the output signal of the output amplifier 7a, green (G) is always output, so that the color selection switch 11a to which the signal of the output amplifier 7a is input can be always turned on. There is no need to switch. In the case of the output signal of the output amplifier 7b, in a certain row, the blue (B) color selection switch 11b is turned on, all the blue (B) output signals are read into the blue (B) of the external memory 10, and in the next row, The red (R) color selection switch 11c is turned on, and all the red (R) output signals are read into the red (R) of the external memory 10. Therefore, the color selection switches 11b and 11c may be switched only when switching the row.
[0028]
FIG. 2 shows output waveforms at the output amplifiers 7a and 7b of the MOS solid-state imaging device 12 according to the present embodiment. In the case of an operation of processing pixel signals obtained from the pixels 1 in the array shown in FIG. 1, as shown in FIG. 2A, the output amplifier 7a outputs pixel signals on the n-th row and the (n + 1) -th row, respectively. G1 (n), G2 (n), G3 (n), G1 (n + 1), G2 (n + 1), and G3 (n + 1) are output, and the output amplifier 7b outputs B1 (n) as shown in FIG. n), B2 (n), B3 (n), R1 (n + 1), R2 (n + 1), R3 (n + 1) are output. As the output signals of the output amplifiers 7a and 7b, the same color signals from non-adjacent pixels in the same row are continuously output. Therefore, when accumulating in the external memory 10 of the external circuit 13, it is not necessary to continuously operate the color selection switches 11a to 11c for sorting and selecting colors at high speed. That is, as described above, in the case of the output signal from the output amplifier 7a, it is not necessary to switch the color selection switch 11a for both the nth row and the (n + 1) th row. The switching operation of the color selection switches 11b and 11c only needs to be performed twice when switching the row of the (n + 1) th row.
[0029]
As described above, in the present embodiment, in order to read the pixel signals of the two rows of the n-th row and the (n + 1) -th row into the external memory 10, the number of switching times of the color selection switches 11a to 11c may be two, and the related art In contrast to the necessity of switching the color selection switch 12 times, the speed of the color selection switches 11a to 11c can be reduced, and the speed of signal output can be increased.
[0030]
Further, in the output signal, the same color is continuous and is not affected by the adjacent color signal, so that color mixing can be prevented and high image quality can be realized. In particular, when the signal output speed is increased, the effect of reducing the speed of the color selection switches 11a to 11c and improving the image quality by preventing color mixing is great.
[0031]
In the above embodiment, all the colors are read out continuously in each row. In this case, the effect is the greatest. However, if at least two identical signals are output continuously, the signal output speed is high. And the effect of reducing the speed of the color selection switch and improving the image quality can be obtained.
[0032]
In the above embodiment, the case where there are two horizontal signal lines and two output amplifiers is shown. However, when there are three or more, the effects of increasing the signal output speed, decreasing the speed of the color selection switch, and increasing the image quality are obtained. Is even bigger.
[0033]
In addition to the case where the signal of each row is input to the row memory unit and read out to the output signal line as in the above embodiment, the signal of each column is input to the column memory unit and read out by the output signal line. The present invention can be similarly applied.
[0034]
The present invention is not limited to the case where an external memory for each color is provided as an external circuit as in the above embodiment, and the present invention can be similarly applied to a case where an external circuit is built in a solid-state imaging device. .
[0035]
Further, the present invention is not limited to the case of having the primary color filters of R, G, and B as in the above-described embodiment, and complementary color filters such as cyan (Cy), magenta (Mg), yellow (Ye), and green (G) may be used. The present invention can be similarly applied to a case in which the device has the same.
[0036]
Further, in the above-described embodiment, although it is not shown to have optically black pixels (optical and black), an optically black pixel region is arranged around the image pickup unit or in the image pickup unit. The present invention can be similarly applied to a case where a signal of an optically black pixel other than a color signal is read out into an output signal line.
[0037]
【The invention's effect】
According to the solid-state imaging device of the present invention, it is not necessary to operate the color selection switch in the external circuit at high speed for each pixel signal, and a low-speed switch operation only at the time of color switching is sufficient. In addition, since parallel output is possible, high-speed output is enabled, and it is easy to increase the speed of the entire camera system including the solid-state imaging device.
[0038]
In addition, among the pixel signals in each row or each column, the same color signal can be output from different output amplifiers, and the same color in an adjacent row can be output from the same output unit. Therefore, the colors of the pixel signals adjacent on the time axis become the same, color mixing affected by the mutual colors is prevented, and high image quality can be realized.
[Brief description of the drawings]
1 is a diagram showing the configuration of a MOS solid-state imaging device and an external circuit according to an embodiment of the present invention; FIG. 2 is an output waveform diagram of an output amplifier in the MOS solid-state imaging device of FIG. 1; FIG. 4 is a diagram showing the configuration of a MOS solid-state imaging device and an external circuit of FIG. 4. FIG. 4 is an output waveform diagram of an output amplifier in the MOS solid-state imaging device of FIG.
1 pixel 2 vertical shift register 3 vertical signal line 4 row memory unit 5 horizontal shift register 5a, 5b, 51 readout switch 6a, 6b output signal line 7a, 7b output amplifier 8, 12 solid-state imaging device 9, 13 external circuit 10 external memory 11, 10a, 10b, 10c Color selection switch

Claims (7)

An imaging unit in which a plurality of unit pixels that photoelectrically convert incident light are two-dimensionally arranged to include a plurality of types of rows having different color arrangements, an output signal line from which pixel signals of the imaging unit are read, An output unit for outputting a signal of an output signal line;
Having a plurality of sets of the output signal line and the output unit,
Pixel signals obtained from a plurality of non-adjacent pixels of the first color in the first row are sequentially and continuously output from the first output unit, and a pixel signal different from the first color in the first row is output. Outputting pixel signals obtained from a plurality of non-adjacent pixels of the second color sequentially from the second output unit;
Thereafter, when reading out the pixel signals in a second row having a different color arrangement from the first row, when the pixels of the first color are included in the second row, the second row is read. Wherein the pixel signals of a plurality of non-adjacent pixels of the first color are sequentially and sequentially read out to the first output signal line. An imaging unit in which a plurality of unit pixels that photoelectrically convert incident light are two-dimensionally arranged to include a plurality of types of rows having different color arrangements, an output signal line from which pixel signals of the imaging unit are read, An output unit for outputting a signal of an output signal line;
Having a plurality of sets of the output signal line and the output unit,
When reading out the signal of each pixel in the first row, if the row includes pixels of a plurality of colors, the pixel signals in the first row are sequentially output from the different output units for each color. ,
Thereafter, when reading a second row having an arrangement different from that of the first row, if a pixel of a specific color that matches the color of a pixel in the first row is included in the second row, Reading a pixel signal of at least one pixel of the specific color in the second row to the output signal line from which a pixel signal of a pixel of the color in the first row is read. Solid-state imaging device. 3. The pixel according to claim 1, wherein pixel signals of pixels of different colors in the same row are simultaneously read out to the different output signal lines, respectively, and then output from the output units connected to the respective output signal lines. Solid-state imaging device. An imaging unit in which a plurality of unit pixels that photoelectrically convert incident light are two-dimensionally arranged to include a plurality of types of columns having different color arrangements, an output signal line from which pixel signals of the imaging unit are read, An output unit for outputting a signal of an output signal line;
Having a plurality of sets of the output signal line and the output unit,
Pixel signals obtained from a plurality of non-adjacent pixels of the first color in the first column are sequentially and continuously output from the first output unit, and a pixel signal different from the first color in the first column is output. Outputting pixel signals obtained from a plurality of non-adjacent pixels of the second color sequentially from the second output unit;
Thereafter, when reading out the pixel signals in a second column having a different color arrangement from the first column, if the pixels of the first color are included in the second column, the second column is read. A solid-state imaging device, wherein pixel signals of a plurality of non-adjacent pixels of the first color in a column are sequentially and sequentially read out to the first output signal line. An imaging unit in which a plurality of unit pixels that photoelectrically convert incident light are two-dimensionally arranged to include a plurality of types of columns having different color arrangements, an output signal line from which pixel signals of the imaging unit are read, An output unit for outputting a signal of an output signal line;
Having a plurality of sets of the output signal line and the output unit,
When reading out the signal of each pixel in the first column, if the column includes pixels of a plurality of colors, the pixel signals in the first column are sequentially output from the different output units for each color. ,
Thereafter, when reading a second column having an arrangement different from that of the first column, a pixel of a specific color that matches the color of a pixel in the first column is included in the second column. Reading a pixel signal of at least one pixel of the specific color in the second column to the output signal line from which a pixel signal of a pixel of the color in the first column is read. Characteristic solid-state imaging device. 6. The pixel according to claim 4, wherein pixel signals of pixels of different colors in the same column are simultaneously read out one by one to the different output signal lines, and then output from the output units connected to the respective output signal lines. Solid-state imaging device. A camera or camera system equipped with the solid-state imaging device according to claim 1.

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