JPS61234686A - Color solid-state image pickup device - Google Patents

Abstract

PURPOSE:To eliminate frame after image to improve the picture quality by reading one of two solid-state image pickup element, one of which has a bicolor color filter and the other has a four-color color filter, while shifting it by one horizontal scanning line in every field. CONSTITUTION:A solid-state image pickup element 1 having a color filter of two kinds of longitudinal stripe and a solid-state image pickup element 2 having a color filter of four kinds of that are so arranged that they are shifted form each other by the pitch of a half picture element in the vertical direction, and an incident optical image 6 is focused on elements 1 and 2 by a half mirror 7 and a total reflection mirror 8. The n-th horizontal scanning line of the element 1 and the (n-1)th horizontal scanning line of the element 2 are read out simultaneously in an odd field, and the n-th horizontal scanning line of the element 1 and the n-th horizontal scanning line of the element 2 are read out simultaneously in an even field. Signals are synthesized and are subjected to color separation by a synthesized signal processing circuit 4 and are taken out from an output terminal 5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a color solid-state imaging device for use in, for example, a high-definition video camera, and particularly to a color solid-state imaging device that uses two solid-state imaging elements to achieve high resolution. It is.

[Conventional technology]

Figure 7 is an example! 1 is a configuration diagram showing a conventional imaging method disclosed in Publication No. 56-40546 which achieves high resolution using two solid-state imaging devices. In the figure, 1, 2
3 is a drive signal generator for driving each solid-state image sensor 1 and 2; 4 is a synthesis signal processing circuit that combines the signal outputs of each solid-state image sensor 1.2; 5 is an output terminal; 6 is an incident optical image, and 7 is a half mirror 18 or a total reflection mirror.

Next, the operation of the conventional imaging system shown in FIG. 7 will be described. The incident optical image 6 is divided into two by a half mirror 7 and a total reflection mirror 8, and the two solid-state image sensors 1 and 2 are
It converts photoelectrically. Only two solid-state image sensors 1 and 2 are installed horizontally or vertically, or horizontally and vertically shifted, and the signals of these two solid-state image sensors 1 and 2 are driven by a drive signal generator 3, and a composite signal processing circuit 4 is used to generate multi-spatial signals. Synthesis processing is performed as a signal whose position is shifted. Then, at the output terminal 5, a signal equivalent to a signal from one solid-state image sensor with twice the number of pixels is obtained.

[Problem that the invention seeks to solve]

In the conventional imaging system using two solid-state imaging devices 1 and 2 as described above, when applied to standard TV systems (NTSC system and others) that perform 2:1 interlacing, the vertical pixel shift is In order to implement interlaced scanning and color separation as a color solid-state imaging device, it was necessary to devise the arrangement of color filters. In addition, in order to simplify the configuration of the color filter, if a configuration is adopted in which the signals of each solid-state image sensor 1 and 2 are read out for each frame,
There was a problem in that an afterimage called a frame afterimage occurred, resulting in a significant deterioration of image quality.

This invention was made to solve this problem, and even in the case of a standard TV system that performs 2:1 interlacing, it uses two solid-state images in the vertical direction with twice the resolution (scanning) in the vertical direction. The object of the present invention is to obtain a color solid-state imaging device without frame afterimages.

[Means for solving problems]

In the color solid-state imaging device according to the present invention, one of the two solid-state imaging devices has two types of vertical striped color filters CI+C2, and the other solid-state imaging device has four types of color filters. c, , c, , c
3. c, and one of the two solid-state image sensors can be read out by shifting one horizontal scanning line for each field.

[Effect]

In the color solid-state imaging device of the present invention, the two solid-state imaging devices are read out sequentially in the vertical and horizontal directions according to the standard TV system. The solid-state image pickup device arranged above the pixel pitch is configured to perform vertical readout with a shift of one horizontal scanning line for each field. - [Example of Implementation] □ Fig. 1 is a Mizuko block diagram of a solid-state image sensor used in a color solid-state image sensor which is an embodiment of the present invention, and Fig. 2 is a diagram showing the color solid-state image sensor of Fig. 1. FIG. 2 is a configuration diagram showing an imaging method. In each figure, reference numerals 1 and 2 indicate solid-state image sensors disposed vertically shifted by one pixel pitch relative to the optical image; 3 a drive signal generator for driving each of the solid-state image sensors 1 and 2; 4; is a synthesis signal processing circuit that synthesizes the output signals of the solid-state image sensors 1 and 2, 5 is an output terminal, '6 is an incident optical image,
A half mirror 18 which divides the incident optical image 6 into two squares is a total reflection mirror which totally reflects the optical image divided and reflected by the half mirror 7. Further, 11 is a pixel having a photoelectric conversion function composed of a photodiode or the like, and 15 to 18 are color filters C1 to C4 provided above the pixel 11 for color separation.

FIG. 3 is a configuration diagram showing an example of a drive signal generator that is a component in the imaging method shown in FIG.

In the figure, 31 is an oscillator, 32 is a synchronization signal generator, 3
3 is a frequency divider, 34 is a horizontal drive signal generator that generates a signal for driving each solid-state image sensor 1 and 2 in the horizontal direction based on the output of the frequency divider 33, and 35 is a synchronization signal generator 32. Odd from the synchronization signal output.

A field discriminator for discriminating even fields; 36 is a vertical drive signal generator'; 37 is the output of the vertical drive signal generator 36; and 37 is the output of the vertical drive signal generator 36; This is a selection circuit that shifts only the line. That is, the horizontal drive signal H drives each solid-state image sensor 1.2 shown in FIG. 2 at the same time, and the vertical drive signal v1 drives the solid-state image sensor 1. The vertical drive signals V2, which are shifted by scanning lines, are supplied to drive the solid-state image sensor 2, respectively.

Next, the operation of the imaging system using the color solid-state imaging device which is an embodiment of the present invention shown in FIG. 2 will be described. The incident optical image 6 has the same magnification and the same brightness (7 of the incident optical image 6) by a half mirror 7° total reflection mirror 8,
An image is formed on each solid-state image sensor 1, 2 arranged with a pixel pitch shifted in the vertical direction. Each of the solid-state image sensors 1.2 used in this invention includes color filters C115, C216, and C317 having different spectral transmission characteristics, as shown in FIG.
and C418. That is, in the solid-state image sensor 1, each color filter C115 and C21 of vertical stripes are used.
Place 6. In the solid-state image sensor 2, four pixels in the second row and the second column are set as one unit, and the color filters C115 and 0216 are arranged in the first row, and the color filter C817 is arranged below the color filter C115 in the second row. , color filter C
Color filters C618 are arranged below the color filters 216 and 216, respectively. This four-pixel unit is arranged over the entire light-receiving surface of the solid-state image sensor 2.

Further, the solid-state image sensors 1 and 2 are arranged vertically, for example, with the solid-state image sensor 2 shifted upward by one pixel pitch,
The driving signal generator 3 reads out the horizontal scanning lines by shifting the position of one horizontal scanning line by one field for each field, and the composite signal processing circuit 4 synthesizes and separates the signals read out simultaneously from each solid-state image sensor 1.2 into nine colors. It is taken out from the output terminal 5 as a color signal.

This operation will be explained in detail using FIG. 4.

As shown in FIG. 4, the solid-state image sensors 1.2 are arranged relatively vertically shifted by the upper pixel pitch, and for example, in an odd field, the n-th horizontal scanning line of the solid-state image sensor 1, The (n-1)'th horizontal scanning line of the solid-state image sensor 2 is read out simultaneously, and in the even field, the n-th horizontal scanning line of the solid-state image sensor 1 and the (n')-th horizontal scanning line of the solid-state image sensor 2 are read out simultaneously. horizontal scan lines are read out simultaneously. In this way, the drive signal generator 3 reads out the horizontal scanning lines of the solid-state image sensor 2 with a shift of one line (depending on the field), and the composite signal processing circuit 4 reads out the horizontal scanning lines of the solid-state image sensor 2 that are read out simultaneously. Since the signals are combined, the effective scanning line is the center position of the scanning lines of each solid-state image sensor 1 and 2 that are read out at the same time, and the effective scanning line of the odd field and the effective scanning line of the even field have a ratio of 2:1. Fully interlaced.

The next K color signal processing is performed, for example, as follows. Now, set color filter 'C, 15 to yellow (Yo).

Change color filter C716 to cyan (Cy)e color filter C3
Assuming that 17 is green (G) and the one-color filter C418 is transparent (W), the luminance signal Y and color signal (R2B) in this case are obtained by the following processing. Now, as an odd field, the n-th row of solid-state image sensor 1 and (n-1)' of solid-state image sensor 2 are
When a signal is extracted by combining the (n+1)th row of the solid-state elastic image sensor 1 and the (n')th row of the solid-state image pickup device 2, the components of the resulting color signal are as shown in FIG. If this color signal component is subjected to signal processing by a composite signal processing circuit 41C as shown in FIG. 6, the luminance signal Y=R12G
In addition, the color signal (R, B) can be extracted from the modulation component, and by using an IH delay line, the signal of the n-th row and the signal of the n+1-th row are synchronized, and the B signal is obtained. is from the modulation component itself, so the R signal is the nth row signal and n+1
Each can be obtained by taking the difference between the signals in the row.

In the above embodiment, yellow (Yo) is applied to each color filter C115 of the vertical stripes of the solid-state image sensor 1, cyan (Cy) is applied to C, 16, and each color filter C115 of the solid-state image sensor 2 is
We have explained the case where yellow (Ye) is used for C,16, cyan (Cy) for C,16, green (G) for Cs17, and transparent ('W)t- for C418, but when using other color filters, the brightness The same effects as in the above embodiments can be achieved, except that the signal processing method for obtaining the signal Y and the color signals (R, B) is different.

〔Effect of the invention〕

As explained above, the present invention provides a color solid-state imaging device in which a solid-state imaging device having vertically striped two-color color filters and a solid-state imaging device having four-color color filters are arranged vertically shifted by one pixel pitch. The horizontal scanning line of one solid-state image sensor is read out once per field.
Since the lines are shifted, 2:1 interlacing is performed, making it possible to capture color images with twice the resolution (scanning lines) in the vertical direction.In addition, the readout of each solid-state image sensor is performed in each field. Because of this, excellent effects such as no occurrence of afterimages called frame afterimages can be achieved.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing a solid-state image sensor used in a color solid-state imaging device that is an embodiment of the present invention, FIG. 2 is a configuration diagram showing an imaging method by the color solid-state imaging device of FIG. 1, and FIG. is a configuration diagram showing an example of a drive signal generator that is a component in the imaging method shown in FIG. 2, FIG. 4 is a diagram for explaining the operation in the imaging method shown in FIG. 2, and FIG. An explanatory diagram of a color signal obtained by the imaging method shown in FIG. 2,
FIG. 6 is a configuration diagram showing an example of a composite signal processing circuit that is a component of the imaging method shown in FIG. 2, and FIG. 7 is an imaging method with high resolution using two solid-state imaging devices FIG. In the figure, 1, 2... solid-state image sensor, 3... drive signal generator, 4... composite signal processing circuit, 5... output terminal, 6... incident optical image, 7... Half mirror 18
... Total reflection mirror, 11... Pixels, 15 to 18...
・Color filters C8 to C4, 31...Oscillator, 32...
- Synchronization signal generator, 33... Frequency divider, 34... Horizontal drive signal generator, 35... Field discriminator, 36.
. . . Vertical drive signal generator, 37 . . . Selection circuit. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (2)

[Claims] (1) An image that is optically divided into two halves in the vertical direction
A first solid-state image sensor having two types of vertical stripe color filters C_1 and C_2 arranged at positions with different pixel pitches, and four types of color filters C_1, C_2, C_3,
The second one, which has two types of C_4 arranged in a mosaic pattern each in the vertical and horizontal directions.
A solid-state image sensor and a solid-state image sensor are provided.
By performing photoelectric conversion using two solid-state image sensors, obtaining signals from the two solid-state image sensors during each line scan, and changing the combination of the scanning lines of these two solid-state image sensors for each field, interlacing is achieved. A color solid-state imaging device characterized by: (2) Among the two solid-state image sensors, two types of vertical stripe color filters C_1 of one solid-state image sensor are yellow (
Y_e), the color filter C_2 is made of cyan (Cy), the four types of color filters C_1 of the other solid-state image sensor are made of yellow (Y_e), and the color filter C_2 is made of cyan (Cy).
y), color filter C_3 is green (G), color filter C_4
2. The color solid-state imaging device according to claim 1, wherein the color solid-state imaging device is made of transparent (W).