JPS60264186A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To reduce the cost, to attain ease of manufacturing and to improve the resolution by arranging CCDs of delta arrangement to the image forming plane of the object to blue, red and two green signals, arranging the two CCDs to the green object images while shifting by a specific interval and moving all the CCDs at each field. CONSTITUTION:The light obtained from the object is resolved into the object image having the blue, red and two green spectral characteristics at the resolving optical system 22 through a lens 21 and formed into the object image to the BCCD27, RCCD28, GCCD29 and GCCD30 through each optical low pass filter. The photodetecting section of the GCCD I 28 and the GCCDII30 is arranged while being shifted by 2d picture elements in the horizontal direction, an output of the GCCDII30 is delayed at a delay circuit 37 by a time corresponding to the interval 2d for shifted picture elements and a green signal synthesized at a synthesizing circuit 38 is obtained. Thus, the signal is equivalent to a signal obtained with a CCD having a horizontal pitch of 2d and a vertical pitch of 2h.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a solid-state imaging device used in a color television camera in a high-definition television system.

Conventional configuration and its problems In recent years, the Standard Television System (NTSC).

PAL, 51! For example, a high-definition television system that compresses the bandwidth four times and transmits data is proposed in the Technical Report of the Television Society of Japan, Vol. .

The camera section of a conventional high-definition television system will be described below.

Figure 1 is a diagram showing the configuration of the camera section of a conventional high-definition television system.
R), green ((1), blue (B) male imaging fee, 4[R,G
, a luminance signal (Y) and a color difference signal (CW) from the B video signal.
) and (cN), AD the luminance signal to 5 with a clock of frequency SW H2 at period t1/4
AD converter for conversion, field offset sampling for sampling so that it has an offset relationship in the horizontal direction every field, 7 is a still image filter that passes the band necessary for still images, 8 is necessary for moving images A video filter that passes the band, a 9-digit frame memory 1.1 o is a motion vector detector that detects vectors for pan and tilt movements of the camera, and a frame memory 2 and 12 [frames] whose readout time is controlled by a motion vector detection signal. 13 is a switch that switches between still image mode and video mode using a video detection signal;
14 is sub-sampling for sampling in an offset relationship for each horizontal scan within a field.The operation of the camera section of the high-definition television system configured as described above will be described below.

First, the signals obtained from the R, G, and B image pickup tubes are synthesized in matrix 4, and a luminance signal (Y) and a color difference signal (CW) are synthesized.
and (C'N) are obtained. Next, the luminance signal (Y) is subjected to AD conversion at a clock frequency SW Hz in an AD converter.

The timing of this AD converter is at the spatial sampling points a and b shown in FIG.

Matches c, d, and e. In Figure 2, ○vi4 n+
1st field, mouth [4n42nd field,
・i 4 n + 3rd field, 40 + 4 in ■
Represents the sampling point of the th field. That is, the spatial gap d corresponds to a period of 1174 and a frequency of 5 Hz, and sampling points are arranged horizontally and vertically in a square. Next, by the field offset sampling 6, the spatial sampling points a, b, c, and el shown in FIG. 2 are sampled.
Sampling is performed at a frequency of SW/2H2, and the phase relationship of sampling points between odd horizontal scans and even horizontal scans is set to 180
°C, and the relationship between the sampling points of the odd and even fields is set to an offset relationship.

Next, the video signal output from the field offset sampling 6 is band-limited by the still image filter and the moving image filter 8, which are two-dimensional low-pass filters that pass only the shaded areas shown in FIGS. 3 and 4, respectively. On the other hand, the motion vector detection 1o compares the output of the field offset sampling 6 with the signal of one frame before, which is obtained by delaying the output of the field offset sampling 6 by one frame period in the frame memory I(9), and the output of the field offset sampling 6, that is, the current signal. Part 7, calculate the vector for the tilt movement.

Next, the output of the field offset sampling 6 is stored in the frame memory I (11), and when read out one frame later, it is moved by the amount of the vector calculated by the motion vector detection 10. In other words, the output of the frame memory I (11) and the output of the field offset sampling 6 are synchronized with the output of the frame memory II (11) so that signals having exactly the same timing with respect to panning and tilting movements of the camera section are obtained. The video detection 12 compares the output obtained by controlling the readout time and the field offset output, and detects movements other than tilt and tilt of the camera unit, such as zooming, or partial movements within the screen. Detect the part.

Next, based on the signal detected by the video detection 12,
The outputs of the still image filter 7 and the video filter 80' were cut off in Switzerland 13, and the subsampling 1
4, in the 4n+1st field, sample the sampling point &, in the 4n4-2nd field, sample the sampling point C, in the 4n+3rd field, sample the sampling point C, and in the 4n+4th field, sample the sampling point d. At this sampling period [11], the frequency becomes S W / 4H,,z.

Therefore, one screen consists of four fields, and a still image (
(including burn and tilt of the camera section), the receiving side uses frame memory to two-dimensionally synthesize 4 fields and interpolate the signals at sampling points &, b, c, and d for sampling. By obtaining the signal at point e, a video signal having the spatial frequency region indicated by diagonal lines in FIG. 3f can be reproduced on the monitor. Since there is no correlation between fields in the video part, for example, in the case of the 4n+1st field, the signal at sampling point 6 is interpolated using sampling point a in that field, and the spatial frequency domain shown in Fig. 4 is obtained. A video signal with a

As a result of the above, even though the sub-sampling frequency S/+Hz is being transmitted to the receiving side, the horizontal frequency S
The reason why a video signal in the W/2 Hz band can be transmitted is because the sampling positions between fields are in an offset relationship, and since the correlation between fields can be detected, aliasing interference can be removed. Regarding moving images, since there is no correlation between fields, aliasing interference will occur if a video signal in the horizontal frequency band SW/2 Hz is transmitted, so it is necessary to keep the video signal band to SW/4 Hz. Therefore, the video filter 8
By sampling the video signal of the still image filter 7 in the subsampling 14 for a still part, an image with less aliasing can be obtained.

In a high quality system where the sampling frequency SW in the AD converter is approximately 4 MHz, approximately 1500 sampling points horizontally and approximately 1000 vertically are required within the effective screen. If a solid-state image sensor for R, G, and B is used instead, a solid-state image sensor with a pixel count of 1,500 horizontally and approximately 1,000 vertically is required, and the processing after the matrix is similar to that of an image pickup tube, resulting in the same image. I can get a signal. For example 2/3
Although it can be realized in a product with a solid-state image sensor of 1.5 inch size, it only requires 400 horizontal pixels. Approximately 500 vertical pixels and 150 horizontal pixels
0. It is impossible with the current technology to satisfy various performances with a vertical 1000 solid-state image sensor. Moreover, if it is manufactured in a size larger than 1 inch, it will be very expensive. Therefore, if you try to use a solid-state image sensor to configure the camera section of a high-definition television system, it will be impossible to use a 2/3-inch solid-state image sensor, and you will have to use a very expensive 1-inch or larger solid-state image sensor. The problem was that it had to be used.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a solid-state imaging device for a high-definition television system using a solid-state imaging device that can be manufactured into a product at a very low cost and that solves the problems of the conventional example. .

Structure of the Invention According to the present invention, the horizontal rows of a plurality of light receiving sections arranged at a predetermined pitch in the horizontal direction are arranged so that the light receiving sections of each of the even-numbered horizontal rows are aligned vertically with the light-receiving sections of each of the even-numbered horizontal rows arranged at a predetermined pitch in the horizontal direction. The first. Second. Third. A 40th solid-state image element is provided on the imaging plane of the first and second object images having the same spectral characteristics.
A second solid-state image sensor is disposed on the imaging plane of the third and fourth object images having different spectral characteristics. A fourth solid-state image sensor is arranged, and the first and second image sensors are arranged to correspond to the first and second subject images. The positional relationship between the light receiving sections of the second solid-state image sensor is such that the light receiving sections of the first and second solid-state image sensors are shifted horizontally by half the horizontal pixel interval of the solid-state image sensor. ．． A second solid-state image sensor is arranged, and the first solid-state image sensor is arranged.
．． Second. 3rd and 4th subject images, respectively. Second. 3. The relative positional relationship with the fourth solid-state image sensor is set to 4.
For n+1 (nH integer) fields, 1/4 of the horizontal pixel interval in the 4n+2 field, 1/2 of the vertical pixel interval in the vertical direction, and 2/2 of the horizontal pixel interval in the 4n+3 field In the 1.4n+4 field, three quarters of the horizontal pixel interval in the horizontal direction. This is a solid-state imaging device configured to shift one half of the vertical pixel interval in the vertical direction, and by capturing an object image with the same spectral characteristics using two solid-state imaging devices whose pixels are shifted, one frame can be captured. Figure 5 is an explanation of an embodiment that can detect motion between frames and obtain a high-resolution video signal by changing the positional relationship between the subject image and the solid-state image sensor in each of four fields. FIG. 6 is a block diagram of a solid-state imaging device according to an embodiment of the invention. Photodetectors (PDs) are arranged horizontally at a pitch of 46 (same length as d in FIG. 2), and vertically. Solid-state image sensors (this arrangement is generally called a delta arrangement) are arranged with a pitch of 2h (h is the same length as d in Figure 2) so that the light receiving parts of the odd and even rows are located in the middle. Here, a 1 ccD image sensor is used (hereinafter abbreviated as QCD). Figure 7 is a diagram showing the mutual arrangement of two CODs for a subject image having the same spectral characteristics.
nk, Bnk ij n CCC in vertical row in horizontal row
D1. The light receiving section of GOCDI is shown. FIG. 8 is a layout diagram showing the respective positions of one light receiving section of the CCD in four fields.

In FIG. 5, 21 is a lens, 22 is a decomposition optical system that separates the subject image into blue, red, and two green subject images, and 23.2
4 [Optical low-pass filter with a pass band indicated by diagonal lines in FIG. 9, 25, 26, optical low-pass filter with a pass band indicated by diagonally lines in FIG.
COD placed on the imaging plane of red and two green subject images,
31, 32, 33, and 34 are shown in Fig. 7. Interpolation circuit to double the Sun 19 Fufu frequency, GCCDI 29 and GCC at the end
A delay circuit that corrects the horizontal pixel shift amount 2d of D13o by converting it into time, 38 is GCCD l 29 and CCC
A synthesis circuit for synthesizing D130 with a time-corrected signal, 3
Blue and red signals of interpolation circuits 35 and 36 and synthesis circuit 3
A matrix that calculates the green signal of 8 and obtains a luminance signal (Y) and two color difference signals (CW) and (ON).
42 and 43 are a timing correction circuit that converts and corrects the horizontal movement distance of a CD into time, an AD converter that converts a luminance signal and a green signal, respectively, 7 is a still image filter, and 8 is a still image filter. The configuration is the same as that of the conventional example shown in FIG. 1, with a moving image filter, Qid frame memory (Qid frame memory), 10U motion quivector detection, and 11ri frame memory 1.12 is moving image detection, switch 13, and subsampling 14.

The operation of the solid-state imaging device of this embodiment configured as described above will be described below.

First, light obtained from an object passes through a lens 21 and is separated into object images having blue, red, and two green spectral characteristics by a decomposition optical system 22, and then passes through each optical low-pass filter to a BCCD 27. RCCD28, GCiCD29. C.C.C.
An image of the subject is formed on D30. BCCD27. R
A subject image limited to the spatial frequency region indicated by diagonal lines in FIG. 9 is formed on the CCD 2B and read out from the BCCD 2 and the RCCD 28, respectively. B (The signal read out from the iCD 27 is sampled by each light receiving part and outputted, and the signals are shown in FIG.
The n-th line is 1d (B) and the (n+1)-th line is (C), which are output in accordance with the offset-node relationship for each horizontal row of the light receiving section array. Also, time t+U: corresponds to [4d] between horizontal pixels of COD.

Next, as shown in FIG. 11, the interpolation circuit 36 uses the n-1st row and n+1st row signals of the same field to
By interpolating to the nth row of the same field, the output shown in FIG. 11(D) whose repetition period is half, that is, t1/2, is obtained. R'C0
For the D28 output as well, a signal with a repetition period t1/2 is obtained by the interpolation circuit 36 in the same way as for the BCCD28 output.

Next, the spatial frequency band of the subject image having green spectral characteristics is filtered by optical low-pass filters 25 and 26, respectively.
CCCD129 and (rcc
D... Imaged on 3o. Here CCCD129 and GOC
As shown in FIG. 7, the light receiving parts of the D130O light receiving part are arranged horizontally shifted by 2d pixels, so the GOcD13
The output of 0 is delayed by a delay circuit 37 and a combined green signal is obtained by a combining circuit 38. This is shown in Figure 11 (K) to (H).
Shown below. Any nth line 0 shown in Figures 11 (IC) and (F)
How to get GCCD I29! :G (from CiD129 output, CF in Figure 11) is delayed by t1/2.
From Figure ((,) and Figure 11(K), the first
Figure 1 (H) is obtained. Kutch, G (icD129
The signal obtained by combining GCCD130 and GCCD130 is a COD signal with a pitch of 2d in the horizontal direction and a pitch of 2h in the vertical direction.
It is equivalent to what you can get with one piece.

Next, interpolation circuits 35, 36 . The blue, red, and green signals sampled at intervals of t1/2 in the horizontal direction obtained from the synthesis circuit 38 are calculated by the matrix 39, and a luminance signal (Y) is generated.
and two color difference signals (CW).

(ON) is obtained. This luminance signal (Y) ld oscillator 23
．． 24, 25, 26 KJ: Since the mutual positional relationship between each ccD and the subject image shown in FIG. 8 moves for each field, the timing correction circuit 4o
Time t1/4s corresponding to horizontal movement amount d in 4n+2 fields for +1 field 4 n +
Time t1/2 corresponding to horizontal movement amount 2d in 3 fields, horizontal movement amount 3 in 4n+4 fields
The time 3t1/4 corresponding to d is corrected to match the positional relationship of the subject image and the time relationship with the luminance signal. The timing correction circuit 40 outputs the AD converter 42. Still image filter 7
, video filter 8. Switch 13. Subsampling 1
4, an equivalent video signal can be obtained in the same manner as in the conventional example shown in FIG.

The next moving object is obtained from the combined green signal obtained from the combining circuit 38. This is because the same green signal can be obtained for a still image by repeating two fields, that is, one frame, so that a moving object part can be detected in one frame memory. BCCD27. R.C.
The signal obtained from CD28 becomes the same signal for a still image by repeating 4 fields, that is, 2 frames, so 1
It cannot be detected in the frame memory of the frame.

Therefore, the output of the synthesis circuit 38 is transferred to the timing correction circuit 4.
1, the time-related timing of the green signal is adjusted in the same manner as the timing correction circuit 40 used for the luminance signal (Y), and the following steps are performed: D converter 43 ° frame memory 199 motion vector detection 1 ° 0 ° frame memory 111 ．． By the moving image detection 12, it is possible to detect a moving subject part in the same manner as the conventional configuration shown in FIG. As described above, the video detection unit 12 receives the signal for the detected moving subject part, and the video filter 8 receives the signal for the video part.
．． For the still image portion, by guiding the output of the still image filter 7 to the subsampling 14 through the switch 13, a signal equivalent to the video signal obtained from the conventional camera having the configuration shown in FIG. 1 can be obtained.

Here, the optical low-pass filters 23, 24 (!:L.

The signal output obtained from the COD is sampled at a horizontal pixel interval of 4d, that is, at a spatial frequency of 1/4d, and is arranged vertically at an offset between lines. Therefore, the spatial frequency of the subject image at which the aliasing signal can be removed is t per field.
This is because li 1/4 d can be used.

Therefore, there is no aliasing noise of blue and red signals in the moving image portion. In addition, when using an optical lobe filter having the band shown in the shaded area in Fig. 10 for an object image having green spectral characteristics that contributes to the resolution of the luminance signal in terms of visibility, it is necessary to use a spatial frequency of 1 for moving images. Although aliasing noise occurs above /4d, it is almost negligible, and the spatial frequency is limited to 1/2d, which does not cause aliasing noise for still images.

This is to obtain a luminance signal with high resolution.

As described above, according to this embodiment, the delta-arranged CO
D is placed on the imaging plane of the subject images for blue, red, and the same two green, and two cans for the green subject image are placed.
For a normal solid-state imaging device, by arranging the QCDs from each other in the horizontal direction so as to shift them by half the horizontal pixel interval, and moving all the QCDs in each field so that they are arranged as shown in Fig. 8. A solid-state imaging device with four times the resolution in the horizontal direction and twice the resolution in the vertical direction can be obtained, and furthermore, it is possible to detect moving images using one frame memory.

In the embodiment, the COD was moved using the transducers 31, 32, 33.degree. 34, but it is also possible to fix the can and move the subject image. In addition, CC as a solid-state image sensor
Although a D image sensor is used, any other type of solid-state image sensor may be used as long as it is a solid-state image sensor that reads data from all light receiving sections to each transfer stage within the vertical blanking period. Further, the timing correction circuits 35, 39 and delay circuits 37 can be omitted by correcting the timing of the readout pulse of each COD by a time corresponding to the amount of horizontal shift in each field or pixel shift. It goes without saying that the optical low-pass filters 23, 24Jd having the band of the shaded area in FIG. 10 can also be used if the influence of high frequencies in the moving image section is ignored. It goes without saying that a similar configuration may also be used to use a subject image having the spectral characteristics of a luminance signal instead of the spectral characteristics of green.

Effects of the Invention The present invention arranges CCDs in a delta arrangement on the imaging planes of subject images for blue, red, and the same two greens, and aligns the two CODs for the green subject images horizontally with respect to each other. By shifting the pixel spacing by half and configuring all CODs to be moved in each field to the arrangement shown in Figure 8, it is possible to create a still image compared to a solid-state imaging device using equivalent CODs. The resolution is four times higher in the horizontal direction and twice the resolution in the vertical direction.Moreover, video detection can be performed using one frame memory, and an interline CCD is used to read out signals from all light receiving sections for each field. It is possible to obtain a solid-state imaging device that does not have frame afterimages (an afterimage that occurs because only signals from the odd or even line light receiving sections are read in one field) caused by

[Brief explanation of drawings]

Figure 1 is a configuration diagram of the camera section of a conventional high-definition television system, Figure 2 is a sampling arrangement diagram showing the sampling positions of each part in Figure 1, and Figures 3 and 4 are two-dimensional optical low-pass filters. FIG. 5 is a block diagram of a solid-state imaging device according to an embodiment of the present invention, FIG. 6 is a block diagram of a delta array CCD image sensor used in the embodiment, and FIG. 7 is a diagram showing green spectral characteristics. Figure 8 shows the relative arrangement of the light receiving section between the two CCDs for the subject image.
Movement diagram of the light receiving part in each field, No. 9
Figure 10 shows the characteristics of the optical low-pass filter, and Figure 11 shows the characteristics of the optical low-pass filter.
The figure is a waveform diagram of each part in FIG. 6 of the embodiment. 22...Resolving optical system, 27, 28, 29, 30
,...COD, 31, 32, 33.34...
... Vibrator, 35.36 ... Interpolation circuit, 38.
... Synthesis circuit, 40.41 ... Timing correction circuit. Name of agent: Patent attorney - Toshio Nakao and one other person Figure 2 Figure 354 Figure 7 Figure 8 Figure 9 ih < * ? MiI 511 1O Figure 21 Enlightenment ■ His cunning Figure 11

Claims (1)

[Claims] The horizontal rows of the plurality of light receiving sections arranged at a predetermined pitch in the horizontal direction are such that each of the light receiving sections of the even numbered horizontal rows is located between the light receiving sections of each of the odd numbered horizontal rows in the vertical direction. The first row is arranged vertically in multiple rows. Second. Third.
The first one has a fourth solid-state image sensor and has the same spectral characteristics. The first image on the imaging plane of the second subject image. A third solid-state image sensor is disposed with a second solid-state image sensor and has different spectral characteristics. The third image on the imaging plane of the fourth subject image. A fourth solid-state image sensor is arranged, and the first
．． The positional relationship between the light receiving sections of the second solid-state image sensor is such that the light receiving sections of the first and second solid-state image sensors are shifted horizontally by half the horizontal pixel interval of the solid-state image sensor.
．． A second solid-state image sensor is arranged, and the first solid-state image sensor is arranged. Second. Third
．． the fourth subject image and the first image, respectively. Second. Third. The relative positional relationship with the fourth solid-state image sensor is 4n+1(na
For 4n+2 fields, 1/4 of the horizontal pixel spacing in the horizontal direction, 1/2 of the vertical pixel spacing in the vertical direction, and 1/2 of the horizontal pixel spacing in the vertical direction for n+3 fields, 1/4 of the horizontal pixel spacing in the horizontal direction In the field, 3/4 of the horizontal pixel interval in the horizontal direction. A solid-state imaging device characterized in that the vertical pixel spacing is shifted by one-half in the vertical direction.