JPS63141485A - Solid-state image pickup element for color picture - Google Patents

Abstract

PURPOSE:To improve color resolution by deciding the color arrangement of a filter of a color exclusive line properly so as to reduce the occurrence of color moire. CONSTITUTION:The fields A, B of a microfilter at a light-receiving section 1 are constituted respectively by 1H lines G, G... for luminance for exclusive use and 1H lines R, B, R, B... for color exclusive use and the luminance signal and chrominance signal are read simultaneously by two lines. The filter arrangement of the color exclusive line is so constituted that the sequence of color is alternate two colors in a horizontal direction, and the location of the two colors is replaced in a 1st scanning line, e.g., the field A and a 2nd scanning line, e.g., the field B, that is, the sampling location of the color is in zigzag as the deviation by one picture element at every field such as RBRB..., in the field A and BRBR... in the field B.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solid-state imaging device for color images, and particularly to a solid-state imaging device for color images in which occurrence of color moiré is reduced and color resolution is improved.

[Prior art]

In a solid-state imaging device for color images, the pixels are independent, so it is possible to attach R, G, and H filters to each, and obtain the corresponding f and color signals with the readout block.
It is well known that this is possible.

Basically, if the filters are arranged in a comb pattern of R2O and B according to the scanning order, signals of each color can be obtained equally, but with this method ↑, signals of the same color can be obtained in 3 pixel cycles. Therefore, the horizontal resolution drops to 8. In reality, the so-called Bayer array is an effective method to prevent apparent resolution degradation. In the Bayer array, filters in columns corresponding to odd-numbered scanning lines are denoted as RGEtG, while filters in even-numbered columns are denoted as GBGB. In that case, at least two pixels are All color signals of R, G, and B are formed within the period of □.

Regarding the image quality of this method itself, there is little decrease in resolution,
Although it is an excellent method, R, G, including the 1H delay line,
The B signal synthesis circuit has a large number of parts and is complex.

The present inventors have previously proposed a solid-state imaging device for color images that can improve color resolution and simplify the color signal synthesis processing circuit (Japanese Patent Application No. 30-223806).

In other words, this solid-state image sensor for color images has 1H lines dedicated to brightness and 1H lines dedicated to color extending horizontally in the pixel portion, which are arranged alternately in the vertical direction, and the brightness signals detected from each line are After supplying both the luminance and color signals to horizontal charge transfer units dedicated to luminance and color, respectively, and reading them out simultaneously, R
,G.

It is provided to synthesize signals such as B or y, R-Y, B-y, etc. The color arrangement of the filter placed on the pixel is such that G (Mg) or W, which is the main component of brightness or brightness, is placed on the line dedicated to brightness, and R or B (Cy or Ye) is placed on the line dedicated to color. It has been proposed that the same color is arranged in the vertical direction, and the two colors are arranged alternately in the scanning line direction.

As a result, we have achieved a solid-state image sensor for color images that has resolution similar to the Bayer array and has a simplified signal synthesis circuit! came.

[Problem that the invention seeks to solve]

However, after further research by the present inventors,
It has been found that the above-mentioned solid-state imaging device for color images tends to cause color moiré when interlaced readout is performed.

This means that the filter color array of the color dedicated line is R or B (
It turns out that this is because the color sampling of Cy or Ye) is arranged every other pixel in the scanning line direction (horizontal direction).

The purpose of the present invention was achieved based on the above circumstances, and
It is an object of the present invention to provide a solid-state imaging device for color images, which can reduce the occurrence of color moiré and further improve color resolution.

[Means for solving problems]

That is, the above-mentioned object of the present invention includes a solid-state image sensor consisting of a light receiving section, a charge transfer section, and a transfer control section, and a mosaic microfilter arranged on the light receiving section in correspondence with the pixels. is a solid state for color images in which each scanning line consists of one line dedicated to brightness and one line dedicated to color extending in the horizontal direction, and the brightness signal and color signal detected by these lines are read out simultaneously. In the image sensor, the color arrangement of the filter of the color-dedicated line is characterized by having two colors alternately in the horizontal direction and in which the two colors are interchanged in a constant pattern in the vertical direction. This is achieved using a solid-state imaging device.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

The figure is a schematic configuration diagram of a solid-state image sensor according to an embodiment of the present invention.

The light receiving section 1 and the vertical charge transfer section 2 are simplified and shown as one block, and the microfilter placed on the light receiving section 1 has a symbol representing its color corresponding to each pixel as shown in the figure. It is divided into G, R and B colors.

In the illustrated embodiment, the solid-state image sensor is adapted to a standard television system, ie, the NTSC system. Therefore, the light receiving section 1 is provided with 1000 rows of photoelectric conversion elements in a substantially vertical direction, and 500 to 800 photoelectric conversion elements are provided in each row in a substantially horizontal direction.

The rows indicated by A and B in the figure are row 1 for reading out the image signals of the A field and the B field, respectively.

As shown in the figure, each of the A and B fields of the microfilter is composed of a 1H line dedicated to brightness (GG...) and a 1H line dedicated to color (RBRB...), and therefore one scan is performed. At the line. The 92H line is assigned and the luminance signal and color signal detected by these two lines are read out simultaneously.

Further, the color-dedicated line filter array has two colors alternately arranged in the horizontal direction, and the positions of the two colors are exchanged between the first scanning line, for example, the A field, and the second scanning line, for example, the B field. In other words, in the A field, RBRB... binding, in the B field, BRB
R...The color sampling positions are shifted by one screen for each field in a so-called houndstooth pattern.

Other components of the device of this embodiment are that the horizontal charge transfer section is composed of a transfer unit 3 dedicated to luminance and a transfer unit 4 dedicated to color. The color signals are supplied to the respective transfer units 3 and 4 via the vertical charge transfer section 2.

The luminance signal and chrominance signal supplied to each transfer unit 6 .

The changeover switch 7 is alternately switched at a cycle of fs/2 (fs: sampling frequency) to separately input the signals of R9B to the matrix circuit B.

M) As is well known, the configuration of the IJ box circuit 6 includes an addition (subtraction) circuit for weighting using resistance elements.

During each field period, the luminance signals and color signals supplied from the horizontal charge transfer units 3 and 4 to the matrix circuit 6 are processed, and signals such as R, G, B, Y, R-Y, B-Y, etc. are obtained. It will be done.

FIG. 2 shows a filter arrangement on a light receiving section according to another embodiment of the present invention.

In FIG. 2, a color G filter is arranged on the 1H line dedicated to luminance, as in the previous embodiment.

The color-dedicated line filter array has two colors, for example R and B, alternating in the horizontal direction. Further, in the fields corresponding to the first scanning line and the second scanning line, the positions of the two colors are the same and the same field 1 and 1 are separated by one scanning line.
It is shifted by a pixel.

FIG. 3 shows yet another embodiment.

That is, in FIG. 3, the brightness-only line is the same as the embodiments of FIGS. 1 and 2 above, except that the color-only line has two colors, for example, R and B, alternating in the horizontal direction. The same is true. In the fields where the positions of the two colors of the white-colored dedicated line correspond to the first scanning line and the fourth scanning line, the positions of the two colors have the same arrangement and correspond to the first scanning line and the second scanning line. The field r and the fields P corresponding to the third and fourth scanning lines are shifted by one pixel.

Although each of the first embodiments uses primary color filters, the element of the present invention can also be achieved using complementary color filters.

〔Effect of the invention〕

According to the present invention, the 1H line dedicated to brightness and the 1H line dedicated to color are arranged vertically as a pair, and the 1H line dedicated to brightness and color are arranged vertically as a pair.
Since the color sampling positions of the filters are changed for each field and arranged in a staggered pattern, the occurrence of color moire can be particularly reduced during interlaced readout, and the color resolution can be further improved.

Further, by vertically dividing the image into 976 pixels (244X2X2), complete interlacing in the NTSC system becomes possible, and the vertical resolution of the image can also be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram illustrating one embodiment of the present invention, and FIG.
FIG. 3 and FIG. 3 are diagrams each illustrating a filter array according to another embodiment of the present invention. 1... Light receiving section, 2... Vertical charge transfer section, 3
．． 4...Horizontal charge transfer section.

Claims (1)

[Claims] 1) A solid-state image sensor consisting of a light receiving section, a charge transfer section, and a transfer control section, and a mosaic microfilter arranged on the light receiving section in correspondence with pixels, and the pixel section is 1
In a solid-state imaging device for color images, which consists of one line dedicated to brightness and one line dedicated to color, extending in the horizontal direction per scanning line of a book, the brightness signal and color signal detected by these lines are read out simultaneously. A solid-state imaging device for color images, characterized in that the color arrangement of the filter of the color-dedicated line is arranged such that two colors are alternately arranged in the horizontal direction and the two colors are interchanged in a fixed pattern in the vertical direction. 2) The solid-state imaging for color images according to claim 1, wherein the positions of the two colors in the color-dedicated line are shifted by one pixel between the first scanning line and the second scanning line. element. 3) A patent claim characterized in that the positions of the two colors in the color-dedicated line have the same arrangement in the first scanning line and the second scanning line, and are shifted by one pixel in the same field separated by one scanning line. The solid-state imaging device for color images according to the range 1 above. 4) The positions of the two colors in the color-dedicated line have the same arrangement in the field corresponding to the first scanning line and the fourth scanning line, and the field corresponding to the first scanning line and the second scanning line, and 2. The solid-state imaging device for color images according to claim 1, wherein fields corresponding to the third scanning line and the fourth scanning line are shifted by one pixel.