JPS6243288A - Color solid-state image pickup device - Google Patents

Abstract

PURPOSE:To attain a color image pickup having double resolution (scan line) in the vertical direction by setting a solid-state image pickup element having a vertical stripe color filter and another solid state image pickup element having a checkered mosaic color filter with a shift given in the vertical direction by 1/2 picture element. CONSTITUTION:An incident light image 6 forms images to the solid-state image pickup elements 10 and 20 set with a shift given in the vertical direction by 1/2 picture element by a half mirror 7 and a total reflection half mirror 8 in the same magnification ratio and with the same brightness (1/2 image 6). The vertical stripe color filters C1 and C2 are provided to the element 10. While the element 20 contains the checkered mosaic color filters C3 and C4 respectively. A drive signal generator 30 reads the signals by shifting the position of the horizontal scan line at a single side by a piece for each field. Then a synthetic signal processing circuit 40 synthesizes and separates the signals read simultaneously out of both elements 10 and 20 and these signals are extracted out of an output terminal 5 in the form of color signals.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color solid-state imaging device, and particularly to a color solid-state imaging device with high resolution using two solid-state imaging devices.

[Conventional technology]

FIG. 7 is a diagram showing a conventional high-resolution imaging system disclosed in, for example, Japanese Patent Publication No. 56-40546. In this figure, 1 and 2 are solid-state image sensors, and 3 is this solid-state image sensor 1. , 2, 4 is a composite signal processing circuit that combines the signal outputs of the two solid-state image sensors 1.2, 5 is an output terminal, 6 is an incident light image, 7 is a half mirror, and 18 is a It is a total reflection mirror.

Next, the operation will be explained. Half mirror the incident light image 6
7 and a total reflection mirror 8, and photoelectrically converted by two solid-state image sensors 1.2. The relative positions of the two solid-state image sensors 1.2 are set to be shifted in the 1/2 pixel pitch direction, the vertical direction, or the horizontal and vertical directions, and the signals of the two solid-state image sensors 1.2 are used as drive signals. Generator 3
When the signals are driven and synthesized by the signal processing circuit 4 as spatially shifted signals, a signal equivalent to a signal from a single solid-state image sensor with twice the number of pixels is obtained at the output terminal 5.

[Problem that the invention seeks to solve]

In the conventional imaging system using two solid-state imaging devices 1.2, the standard TV system (NTSC) with 2:l interlacing is used.
When applying this to a color solid-state imaging device, vertical pixel shifting requires interlaced scanning and color separation, and in order to realize a color solid-state imaging device, it was necessary to devise the arrangement of color filters. Furthermore, in order to simplify the configuration of the color filter, when a configuration is adopted in which signals from each solid-state image sensor 1.2 are read out for each frame, an afterimage called a frame afterimage occurs, significantly degrading the image quality.

This invention was made to solve the above-mentioned problems, and even in the case of a standard TV system that performs 2:1 interlacing, two solid-state image sensors are arranged vertically at a 1/2 pixel pitch. By staggered arrangement, the object is to obtain a color solid-state imaging bag m that has twice the resolution (scanning lines) in the vertical direction and is free from frame afterimages.

[Means for solving problems]

In the solid-state image sensor according to the present invention, one of the two has a color filter in the form of vertical stripes.

The other type has checkered mosaic color filters, each color filter having different spectral transmission characteristics, and the combination of scanning lines for the signal from one of the solid-state image sensors is changed for each field. .

[Effect]

In the color solid-state imaging device according to the present invention, signals are sequentially read out from two solid-state imaging elements in the vertical and horizontal directions.

Also, vertically 1/2 pixel pixel 1. The solid-state image sensing device disposed above the field is read out in the vertical direction with a shift of one horizontal scanning line for each field.

〔Example〕

FIG. 2 is a diagram showing the basic configuration of the present invention, in which 10 and 20 are solid-state image sensors arranged vertically shifted by 1/2 pixel pitch relative to the optical image, and 30 is the solid-state image sensor 10. .20, 40 is a synthesis signal processing circuit for synthesizing the output signals of the solid-state image pickup device 10.20, and the others 5 to 8 are the same as those shown in FIG.

FIG. 1 is a diagram showing a specific example of solid-state imaging devices 1o and 20, which are constituent elements of the present invention, and in this diagram,
11 is a pixel having a photoelectric conversion function composed of a photodiode or the like, and 01 to C4 are 0 color filters cl and c2, which are color filters for color separation provided on the pixel 11.
is a vertical stripe shape, and color filters C3 and C4
is a color filter arranged in a checkered mosaic pattern.

FIG. 3 shows a drive signal generator 3o which is a component of the present invention.
It is a figure showing a specific example. In this figure, 31 is an oscillator, 32 is a synchronizing signal generator, 33 is a frequency divider, and 34 generates a signal to drive the solid-state image sensor 10.20 in the horizontal direction using the output of the frequency divider 33. a horizontal drive signal generator 35 for determining odd and even fields from the synchronization signal of the synchronization signal generator 32;
6 is a vertical drive signal generator, and 37 is a selection circuit that shifts the output of the vertical drive signal generator 36 by one horizontal scanning line in one field based on the output of the field discriminator 35. That is, the horizontal drive signal H drives the solid-state imaging device 10.20 of FIG. 2 simultaneously, the vertical drive signal v1 drives the solid-state imaging device 10, and the vertical drive signal v2 shifts by one horizontal scanning line for each field. is connected to drive the solid-state image sensor 2o.

Next, the operation of the color solid-state imaging device according to the present invention will be explained. In the configuration shown in FIG. 2, the incident light image 6 is formed by a half mirror 7 and a total reflection mirror 8 at the same magnification and the same brightness (l/2) of the incident light image 6 in the vertical direction.
Solid-state image sensor arranged with a shifted pixel pitch 10.20
is imaged. Solid-state imaging devices 1o and 2 used in this invention
0 has color filters (1, C2, C3, Ca) with different spectral transmission characteristics, as shown in FIG.

That is, in the solid-state image sensor 10, the vertical stripe color filters CI and C2 are arranged as described above,
In the solid-state image sensor 20, checkered mosaic color filters C3 and C4 are arranged.

The solid-state image sensors 10 and 20 are arranged vertically, for example, the solid-state image sensor 20 is shifted downward by l/2 pixel pitch, and the drive signal generator 30 shifts the position of one horizontal scanning line by one for each field. The combined signal processing circuit 40 combines and separates the signals simultaneously read out from the solid-state image sensors 10 and 20, and outputs them from the output terminal 5 as color signals. This operation will be explained in detail using FIG. 4.

As shown in FIG. 4, the solid-state image sensors 10 and 20 are arranged with a relative vertical shift of l/2 pixel pitch, and for example, in an odd field, the n-th horizontal scanning line of the solid-state image sensor 1o and the solid-state image sensor 2o, the n+1st horizontal scanning line of the solid-state image sensor 1o, and the (n+1)'th horizontal scanning line of the solid-state image sensor 2o are simultaneously read out, and in an even field. is the nth scanning line of the solid-state image sensor 1o and the solid-state image sensor 20
The (n+1)'th horizontal scanning line of the solid-state image sensor 10 and the (n+2)'th horizontal scanning line of the solid-state image sensor 2o are simultaneously read out. At this time, the signals that are simultaneously read out are different for the n-th scanning line and the n+1-th scanning line.

In this way, the drive signal generator 30 drives the solid-state image sensor 2.
The horizontal scanning line 0 is read out with a shift in the vertical direction by l lines depending on the field, and the combined signal processing circuit 40 combines the simultaneously read signals of the solid-state image sensor 10 and 20, so that the effective scanning line is read out at the same time. This is the center position of the scanning line of the read solid-state image sensor 10.20, and the effective scanning line of the odd field and the effective scanning line of the even field are 2:l.
Full interlacing can be achieved.

Color signal processing is performed, for example, as follows. Now 1
Color filter C1 is cyan, C2 is yellow, C3 is transparent, C4
is green, the luminance signal Y and the color signal R,
B can be obtained by the following process.

Now, the n-th row of the solid-state image sensor 1o shown in FIGS. 1, 2, and 4 and the n'-th row of the solid-state image sensor 2Q shown in FIGS. 1, 2, and 4 are assumed to be odd fields. and,
In addition, the fi+1st of the solid-state image sensor 10 and the solid-state image sensor 2
0 and the (n+1)'th signal.
At this time, each pixel of the solid-state image sensors 10 and 20 is combined so as to correspond to a filter as shown in the middle and lower left diagrams of FIG. The diagram combining the n'th of 2o is shown in the left diagram in the middle row, and when the solid-state image sensor 10 obtains the signal of the color filter CI, the solid-state image sensor 20 obtains the signal of the color filter C3. It shows that Similarly, at the next time, when the signal of the horizontally adjacent pixel is obtained and the signal of the color filter C2 is obtained in the solid-state image sensor 10, the signal of the color filter C4 is obtained in the solid-state image sensor 20. It is shown that. It also shows that the vertical position of the n-th row of the solid-state image sensor 10 is located below the vertical position of the n'-th row of the solid-state image sensor 20 by a dimension corresponding to half a pixel pitch. There is.

The n+1st row of the solid-state image sensor 10 and the solid-state image sensor 20
A similar diagram of the (n+1)'th row is shown in the lower left diagram of FIG.

To summarize the above, the nth row of the solid-state image sensor 10,
The signal obtained from the n'l-th row of the solid-state image sensor 2o is cl + C3==cyan+transparent=G+B+R+G+B=2G+2B+R C2+Ca=yellow+green=G+R+G=2G+R.

However, cyan is obtained by combining green and blue, transparent is obtained by combining green, red, and blue, and yellow is obtained by combining green and red.

As can be seen from this equation, signals of 2G+2B+R and 200R are obtained alternately in the horizontal direction. A schematic representation of this is shown in the upper diagram of Figure 1g5.

Similarly, the signals obtained from the n+1th row of the solid-state image sensor 10 and the (n+1)'th row of the solid-state image sensor 20 are: C+ +C4=Cyan+Green=G+B+G=2G1B C2+C3=Yellow+Transparent=Q+R+R+G+B =2G+2
R+B becomes as shown in the lower part of Figure 5.

Next, the n-th row of the solid-state image sensor 1° and the (n+1)'-th row of the solid-state image sensor 20 are combined as an even field. This case will be explained in the same way using FIG.

In FIG. 4, the upper left side represents the solid-state image sensor 10, and the upper right side represents the solid-state image sensor 2o, and solid arrows between the two indicate both rows in which two solid-state image sensors are combined in an even field. It shows.

The nth row of the solid-state image sensor 1o and the (
When the signal is extracted by combining with the n+1)'th row,
The combination corresponds to the color filters shown in the middle and lower right figures of FIG. 4. That is, the nth row of the solid-state image sensor 10 and (n+1) of the solid-state image sensor 2o
The signal obtained with the 'th combination is .

C+ +Ca = Cyan + Green = G + B + G = 2G + B C? +C3=yellow+transparent==G+R+R+G+B=2G
+2R+B n+1st row of solid-state image sensor 10 and solid-state image sensor 2o
The signal obtained from the (n+2)'th combination of is CI+C3m cyan+transparent=G+B+R+G+B=2G
+2B+R C2+Ca = Yellow + Green = G + R + G = 2G + R,
Even in the case of an even field, a signal as shown in FIG. 5 can be obtained.

Now, according to FIG. 5, R and G are always outputted as output signals of the n-th row, and B is outputted every other signal in the horizontal direction. Expressing this in a formula, the signal Sn is sn = R + 2G + B + Bs1n ωsj where ω,
/2π indicates the spatial frequency based on the horizontal pixel pitch of the solid-state image sensor 10.20.

Similarly, the signal Sn, + in the n+1 row is Sn-+=R+2G+B+R51n ωst.

What can be seen from these equations is that from each row, the DC component of R+2G+B, from the nth row the AC component of B, and from the n+1 row the R
This means that the amount of alternating current is obtained.

Figure 6 shows the luminance signal Y from these signals.

A circuit block is shown for extracting the DC component Y=R+2G+B and the AC components B51nω,t and R51nω,t as color signals.

The AC component is removed from the input signal through a low-pass filter 41 to produce a Y signal.

Also, if only the modulated components with center frequencies of ω and /2π are taken out by the bandpass filter 42 and detected by the detection circuit 43, then R,! -B component is obtained. However, since the R and B components can only be obtained alternately every other row, the IH delay line 44 is used to generate a signal delayed by one horizontal scanning line time to compensate, and the switch circuits 45 and 48 are used to constantly switch the colors for each row. A signal R or B can be obtained.

In the above embodiment, the color filter CI+02 of the solid-state image sensor 10 is cyan and yellow, and the color filters C3 and C4 of the solid-state image sensor 2o are transparent and green, but other color filters may be used. C1 may be transparent, C2 may be green, C3 may be blue, and C4 may be red. If other color filters are used in this way, a signal processing circuit for obtaining the luminance signal Y and color signals R and B may be used. The same effects as in the above embodiment can be obtained, except that the ratio of each signal component is different.

〔Effect of the invention〕

As explained above, in this invention, a solid-state image sensor having a vertical stripe color filter and a solid-state image sensor having a checkered mosaic color filter are arranged vertically shifted by 1/2 pixel pitch, and one solid-state image sensor Since 2:1 interlace is performed by shifting the readout of the water-mono scanning lines by one line for each field, color imaging with twice the resolution (scanning lines) in the vertical direction is possible. Further, since reading from each solid-state image sensor is performed in each field, there is an advantage that an afterimage called a frame afterimage does not occur.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of a solid-state image sensor used in the present invention, and FIG. 2 is a block diagram showing the basic configuration of the present invention.
FIG. 3 is a block diagram showing one embodiment of a drive signal generator used in the present invention, FIG. 4 is a diagram for explaining the invention in detail, and FIG. 5 is an explanatory diagram of signals obtained by the invention. FIG. 6 is a diagram showing a composite signal processing circuit according to the present invention, and FIG. 7 is a diagram showing an imaging method for achieving high resolution using two solid-state imaging devices. In the figure, 10.20 is a solid-state image sensor, 30 is a drive signal generator, 40 is a composite signal processing circuit, and Cl-C4 is a color filter. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent: Masuo Oiwa (2 others) Figure 1 Lolololololololololololololo Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Procedural amendment (self-motivated) 1. Indication of case Patent application 1980 -0184401 No. 2
・Name of the invention: Color solid-state imaging device 3, Representative of the person making the amendment: Moriya Shiki 5, Detailed explanation of the invention in the specification subject to amendment 6, Contents of the amendment (1) Page 4, line 15 of the specification “I did it.”
is corrected by saying, ``It's something you can get by doing.'' (2) Similarly, on page 4, lines 17-18, "The color solid-state imaging device receives signals from two solid-state imaging devices" is replaced with "The color solid-state imaging device receives signals from two solid-state imaging devices." to correct. (3) Similarly, change “odd, even field” on page 6, line 7 to “
Odd, even field”. (4) Similarly, replace “R or B” on page 14, line 11 with “R
and B”. that's all

Claims (3)

[Claims] (1) A solid-state image sensor having a vertical stripe color filter and a solid-state image sensor having a checkered mosaic color filter are arranged with a 1/2 pixel pitch shifted in the vertical direction, and each color filter has a different spectral transmission characteristic. and further performs composite signal processing in which the signals from the two solid-state image sensors obtained during each line scan of each solid-state image sensor are interlaced by changing the scanning combination of the two solid-state image sensors for each field. A color solid-state imaging device characterized by being equipped with a circuit. (2) The vertical striped color filters of one solid-state image sensor are cyan and yellow, and the color filters arranged in a checkered mosaic pattern of the other solid-state image sensor are transparent and green. 1) The color solid-state imaging device described in section 1). (3) The vertical striped color filters of one solid-state image sensor are transparent and green, and the color filters arranged in a checkered mosaic pattern of the other solid-state image sensor are blue and red. 1) The color solid-state imaging device described in section 1).