JPH0414982A - Color solid-state image pickup device and its signal processing method - Google Patents

Abstract

PURPOSE:To obtain a color solid-state image pickup device with a double high sensitivity characteristic by adding an output of either an odd or an even number column among 1st and 2nd photoelectric conversion unit elements to a photoelectric conversion unit element output from an odd column or an even column different in the row direction. CONSTITUTION:The arrangement of a color filter, noted only for even number fields, is expressed as a 1st column in a unit matrix of 2-row, 2-column consisting of cyan (Cy) + green (G) and cyan (Cy) + magenta (Mg), and as a 2nd column consisting of yellow (Ye) + magenta (Mg) and yellow (Ye) + green (G), and each color filter (comprising two elements) corresponds to each (one) photodetector. Then two color filters are given to one picture element, two column signal outputs are delayed in the frame operation and added to different column signal outputs comprising a same color filter element. Thus, the sensitivity is doubled from the normal frame operation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a solid-state imaging device capable of capturing images with high sensitivity.

BACKGROUND OF THE INVENTION In recent years, as home movies have become more popular, competition for high-sensitivity movies has intensified. In order to increase the sensitivity of movies, efforts are being made to improve the S/N of the solid-state imaging device itself.

Problems to be Solved by the Invention Currently, there are movies on the market that function satisfactorily with a minimum subject illuminance of a few lux, but current solid-state imaging devices, such as incline transfer type CC
There is a limit to dramatically improving the S/N of D.

Means for Solving the Problems In order to solve the above problems, the solid-state imaging device of the present invention uses cyan (Cy), yellow (Ye), magenta (
A plurality of photoelectric conversion unit elements each consisting of one photoelectric conversion element disposed facing two of the four filter elements of Mg) and green (G) are arranged in a two-dimensional manner. , the first, second, third, and fourth charge conversion unit elements are configured by a combination of color filter elements, and the first column includes photoelectric conversion units in the order of the first, first, second, and second. The element array is arranged, and the second column is the photoelectric conversion unit element output of the solid-state image sensor, which is composed of the photoelectric conversion unit element or the photoelectric conversion element array arranged in the order of third, third, fourth, and fourth. Furthermore, the output of the odd-numbered column or the even-numbered column of the photoelectric conversion unit elements of any one of the eleventh and second photoelectric conversion unit elements is calculated from among the photoelectric conversion unit elements that are different in the row direction. The configuration is such that it is added to the photoelectric conversion unit element output from the odd-numbered columns or the even-numbered columns.

Effect: This configuration enables isometric mixing of two pixels compared to the usual one-pixel, two-filter frame accumulation colorization method, and can realize a color solid-state imaging device with twice as high sensitivity characteristics.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a solid-state imaging device according to the present invention.

The solid-state imaging device is an interline transfer CCD including a photoelectric conversion section 1, a vertical transfer section 2, a horizontal transfer section 3, and a signal charge detection section 4. An example of a color filter array is described in the charge conversion section.

Note that the arrangement of color filters placed on each photoelectric conversion unit is as follows: If we focus only on even fields, the first column of the unit array of 2 columns and 2 rows is cyan (Cy) + green (G), cyan (Cy). ) + magenta (M g), second column is yellow (Yen + magenta (M g), yellow (Y
e)+green (G), and each color filter (two elements) corresponds to each (one) light receiving element.

In high-sensitivity operation, the signals photoelectrically converted in the first and second columns of the unit array are delayed by two pixels in the row direction, and added to the signals that have been charge-converted in the third and fourth columns, respectively. As a result, in the n lines of the first field, the image sensor outputs from the third column onwards are outputted in a repetition of 2 (G+Cy) and 2 (Mg+Ye).

Similarly, in the n+l line of the first field, the signals are mixed and the signal output is a repetition of 2 (Mg+Cy) and 2 (G+Ye).

In the n line of the second field, as shown in Fig. 2, charges are read out from the photoelectric conversion elements that were not read out in the first field and mixed, and as a result, the signal output is 2 (G + Cy) and 2 ( Mg+Ye) is output repeatedly.

Similarly, the signals are mixed on the n+1 line of the second field, and the signal output is a repetition of 2 (Mg+Cy) and 2 (G+Ye).

Here, when the primary color components red, green, and blue are R-G-B, they are expressed as Cy=B+G, Ye=R+G, and Mg-R+B.

2 (G+Cy)=2 (B+2G) 2 (M, g+Ye) Mi2 (2R+G+B)2(M
g-+Cy) Mi2 (R+G+2B)2 (G+Ye)
=2 (B+2G).

FIG. 2 shows the state of signal output according to this.

For the element outputs in FIG. 2, the following color difference signals C1 and C2 are obtained by sampling the third and fourth example outputs and taking the difference.

In the first field, n line, Color difference signal C1=2 (2R+G+B) -2(B+2G) =2 (2R-G) In the first field, line n+1, Color difference signal C2=2 (B+2G) -2(R+G+2B) =2 (G-2B) Similarly, in the second field N line: C1=2 (2R-G) Line n+1: C2=2 (G-2B).

On the other hand, the luminance signal Y is sampled from the third and fourth columns, and through electrical low-pass filter processing, the luminance signal Y = 4R 16G + 4B = 2x (2R + 3G + 2B) is obtained for any field line, and the luminance signal is in normal operation. (Y=2R+3G+2B)
It is possible to achieve twice the sensitivity.

As described above, in the present invention, compared to normal frame accumulation colorization, because of the color filter configuration of two-pixel mixing,
A color solid-state imaging device with unprecedented high sensitivity characteristics can be realized.

Note that in the above embodiment, the signal outputs of the first and second columns of the unit array were added to the signal outputs of the third column, fifth column, and fourth column, respectively. It may also be a signal output.

Also, regarding the solid-state imaging device, in the above embodiments, an interline COD is used or a CC having a storage section is used.
D is also fine.

Effects of the Invention As described above, in the present invention, two column signal outputs are delayed in the frame operation of a device with two color filters attached to one pixel, and added to different column signal outputs composed of the same color filter element. This can easily double the sensitivity compared to normal frame operation.

Therefore, its practical effects are extremely large.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a solid-state imaging device according to an embodiment of the present invention, and FIG. 2 is a diagram of image sensor signal output characteristics obtained from the color filter configuration of FIG. 1. 1...Photoelectric conversion unit, 2...Vertical transfer unit, 3...Horizontal transfer unit, 4...Charge detection unit. Name of agent Patent attorney Shigetaka Awano

Claims (2)

[Claims] (1) Cyan (Cy), Yellow (Ye), Magenta (
A photoelectric conversion unit element composed of one photoelectric conversion element arranged opposite to each of the four filter elements of Mg) and green (G) is arranged in a two-dimensional manner. , the first, second, third, and fourth photoelectric conversion unit elements are configured by a combination of color filter elements, and the first column includes the photoelectric conversion units in the order of the first, first, second, and second. The element array is arranged, and the second column is the third, third, and fourth column.
- A means for outputting the photoelectric conversion unit elements of a solid-state imaging device comprising a photoelectric conversion element array in which the photoelectric conversion unit elements are arranged in a fourth order, and further the photoelectric conversion unit elements in odd number columns and even number columns. 1. A color solid-state imaging device, comprising: means for adding the output to the outputs of the photoelectric conversion unit elements in odd-numbered columns and even-numbered columns that are different in the row direction. (2) Cyan (Cy), yellow (Ye), magenta
(Mg) and one photoelectric conversion element arranged facing two of the four filter elements of green (G), a plurality of photoelectric conversion unit elements are arranged in a two-dimensional manner. The first, second, third, and fourth photoelectric conversion unit elements are configured by a combination of color filter elements, and the first column performs photoelectric conversion in the order of the first, first, second, and second. A unit element array is arranged, and the second column is the third
・A photoelectric conversion unit element output of a solid-state image sensor consisting of a photoelectric conversion element array in which the photoelectric conversion unit elements are arranged in a fourth order, and the first and second photoelectric conversion unit elements. Add the photoelectric conversion unit element output of an odd numbered column or an even numbered column in any of the photoelectric conversion unit elements to the photoelectric conversion unit element output from an odd numbered column or an even numbered column among different photoelectric conversion unit elements in the row direction. A signal processing method for a color solid-state imaging device.