JPS6238910B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a solid-state color imaging device that can obtain high horizontal resolution with a small number of picture elements, and
The luminance signal is designed to avoid including folded signals (harmonic components).

First, let's explain an example of a CCD that can be used in this invention.

This CCD is said to be an interline transfer type, and in Figure 1, 1
M and 1N are light receiving sections serving as picture elements, 2 is a vertical shift register, and 3 is a horizontal shift register, which have a CCD configuration. Then, the light receiving section 1
M, 1N are formed in such a way that two of them are set as one set, and the plurality of sets are distributed in a checkered pattern as a whole, and
In each set, the light receiving sections 1M and 1N are arranged in the column direction (vertical scanning direction). Therefore, the light receiving section 1
M is located in an odd numbered row, and the light receiving section 1N is located in an even numbered row. The first sensor voltage Em is supplied to the light receiving section 1M, and the second sensor voltage En is supplied to the light receiving section 1N.

Further, the vertical shift register 2 includes a light receiving section 1M,
It is formed for each column of 1N. This register 2 is the transfer section 2M for 1/2 of one bit.
and the other 1/2 bit transfer section 2N are arranged alternately in the column direction, and transfer sections 2M and 2N constitute 1 bit, but one of the transfer sections 2M in the column direction
Every other unit (shown with diagonal lines) receives the carrier from the light receiving unit 1M, and every other transfer unit 2N (shown in perspective view) in the column direction receives the carrier from the light receiving unit 1N.
The transfer portions 2M or 2N of the same column are formed so as to receive carriers from the light receiving portions 1M or 1N of the same column. The first clock pulse φ _n is supplied to the transfer section 2M, and the second clock pulse φ _o is supplied to the transfer section 2N.

Furthermore, the horizontal shift register 3 is the register 2
The carriers from the register 2 are supplied in parallel and read out in series.

Therefore, the following operations are performed in this CCD. That is, as shown in FIG. 2, during the vertical scanning period Ts of one field period, the sensor voltage Em = "0" and En = "0", so the light receiving sections 1M and 1N have the same voltage as shown in FIG. 3A. As shown, a minority carrier X (the suffix indicates the line number) corresponding to the optical information is accumulated.

Then, when Em = "1" and φ _n = "0" during the period Tm of the vertical blanking period Tv, the third
As shown in FIG. B, the carrier X of the light receiving section 1M is transferred to the transfer section 2M through the output gate of the light receiving section 1M.

Furthermore, in the next period Tn, En = “1” and φ _o = “0”
Then, since φ _n = “1” and φ _o = “0”, as shown in FIG. 3C, the carrier Carrier X is transferred to the transfer section 2N through the output gate. Therefore, in this state, the carrier X (for example,
X ₂ ) and the carrier (for example, X ₃ ) obtained by the light receiving section 1M in the next row are located in the same row of the registers 2 adjacent to each other. Further, the carrier _X1 obtained by the light receiving section 2M in the first row is transferred to the horizontal shift register 3.

Then, during the vertical scanning period Ts, φ _n =
"0" and φ _o = "1", so the carrier X of the transfer section 2N is transferred to the transfer section 2M, as shown in FIG. 3D. Thereafter, by inverting the pulses φ _n and φ _o every horizontal period, the transfer unit 2M,
The 2N carriers X are sequentially transferred to the register 3.

Therefore, as shown in FIG. 4, the register 3 stores, for each horizontal period, the carrier X obtained by the light receiving section 2N in a certain row, and the carrier are obtained point-sequentially, and these are sequentially read out as imaging outputs.

This invention uses such a CCD to perform color imaging.

An example of this will be explained below.

In FIG. 5, 11 is a subject, 14 is a CCD explained in FIGS. 1 to 4, and an imaging lens 12 is provided on the optical path between them.
A color separation filter 13 is provided in front of the CCD 14.

For example, as shown in FIG. 6, this filter 13 is a striped filter portion that has the same width as the length in the column direction of the light receiving sections 1M and 1N, and that transmits all color light, red light, all color light, and blue light. Y, R, Y, B
are arranged repeatedly in the column direction, with these four as one set. In the filter 13, the filter section Y is connected to the light receiving section 1 of the odd row of the CCD 14.
Corresponding to M, the filter section R is the light receiving section 1 of the even numbered row.
N, corresponds to every other light receiving section 1N in the column direction, and in addition, every other light receiving section 1N has a filter section B remaining.
It is set up to correspond to the following.

Therefore, when the image of the subject 11 is projected onto the filter 13 by the lens 12, as shown in FIG.
shall be projected on. Further, the same reference numerals as those of the filter sections Y to B are used for the carrier obtained by the CCD 14 and each color signal obtained thereby. Note that the suffix of the code indicates the row number of the light receiving sections 1M and 1N), and the light receiving section 1 on the odd-numbered row
A carrier Y due to white light is generated at M, a carrier R due to red light is generated at every other light receiving section among the light receiving sections 1N in the even numbered rows, and a carrier B due to blue light is generated at the remaining light receiving sections. .

Then, the sensor voltage is output from the pulse forming circuit 15.
Em, En and clock pulses φ _n , φ _o are CCD14
supplied to Therefore, from CCD14, the 8th
As shown in Figure A, in every other horizontal period, the red signal R and the luminance signal Y become point-sequential signals, and in the remaining every other horizontal period, the luminance signal Y and the blue signal B
A line sequential signal Ec, which is a point sequential signal, is obtained.

Therefore, this signal Ec is supplied to the delay circuit 16 to become a signal Ed delayed by one horizontal period as shown in FIG. At the same time, the sampling pulse is supplied from the forming circuit 15.
Pr, Pb, Pu, Pv are sampling hold circuit 2
1 to 24. Thus, the signals Ec, Ed
During the odd field period, the red signal R, the blue signal B, and the luminance signals Yu and Yv are taken out simultaneously, and during the even field period, as shown in FIG. , as shown in FIG. 8D, the signals R, B, Yu, and Yv are synchronized and taken out. In this case, Fig. 8C,
As shown in D, in any horizontal period, signals R to Yv are extracted by signals from four consecutive rows of light receiving sections 1M and 1N.

Then, the signal Yu is supplied to the low-pass filter 25 to extract the low-frequency component Yl, which is converted into the NTSC
At the same time as being supplied to the encoder 27, the signal Yv is also supplied to the high pass filter 26 to obtain a high frequency component Yh.
is extracted and supplied to the encoder 27, where components Yl and Yh are added to form a new luminance signal.

Further, the signals R and B are supplied to the encoder 27, and the color subcarrier, the burst signal, the composite synchronization pulse Pc, etc. are supplied to the encoder 27 from the forming circuit 15.

In this way, an NTSC color video signal is formed in the encoder 27 and taken out to the terminal 28.

In this way, color imaging is possible, and in this case, according to the present invention, high horizontal resolution can be obtained with a small number of picture elements. That is, the horizontal resolution depends on the high frequency component Yh of the luminance signal, and this high frequency component Yh is obtained from the signal Yv, and
As is clear from FIGS. 8C and 7D and FIG. 7, this signal Yv is obtained from the signal Y of each column of the light receiving section 1N. Therefore, the horizontal resolution corresponds to the number of columns of light receiving sections 1N. However, at this time, the light receiving sections 1M and 1N
is only distributed in a checkered pattern, so the light receiving parts 1M, 1
The number of N may be small. Therefore, high horizontal resolution can be obtained with a small number of picture elements.

Additionally, the high-frequency portion of the luminance signal obtained by a CCD imaging device generally contains an aliased signal (lower sideband component of the carrier luminance signal), but according to the present invention, this does not occur. . That is, the high-frequency component Yh of the luminance signal is obtained from the signal Yv, but this signal Yv is obtained from the signal Y (for example, Y ₁ ) obtained from the light receiving sections 1M in the odd rows and the light receiving sections 1M in the even rows. This is a point-sequential signal with the signal Y (for example, Y ₃ ), and each folded signal included in the signal Y has opposite phases to each other. Therefore, in the signal Yv, the folded signal is canceled out, so that the luminance signal does not include the folded signal.

Furthermore, during the odd-numbered field period, the signal Yu from which the low-frequency component Yl of the luminance signal is extracted includes only the signal Y (for example, Y ₁ ) from one odd-numbered light receiving section 1M, so that the center of luminance is on the odd-numbered row. On the other hand, in the even field period, the signal Yu includes two signals Y (for example, Y ₁ and Y ₃ ) from the light receiving sections 1M in the two odd rows, so the center of brightness is between the two odd rows. It is in the middle of the line and therefore can be interlaced.

Note that the CCD 14 can also be configured as shown in FIG.
N carriers X are transferred to register 2 at the same time);
The sensor voltage is common, and the general
Just supply a clock pulse like a CCD. By extracting the signal Yv from at least the sampling and holding circuit 24 of the sampling and holding circuits 23 and 24 as a luminance signal, a luminance signal with high horizontal resolution and less aliasing distortion can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a front view schematically showing an example of a CCD that can be used in this invention, FIGS. 2 to 4 are illustrations for explaining the same, and FIG. 5 is a system diagram of an example of this invention.
6 to 8 are diagrams for explaining the same, and FIG. 9 is a front view schematically showing another example of a CCD that can be used in the present invention. 13 is a color separation filter, 14 is a CCD, 16
is a delay circuit.

Claims (1)

[Claims] 1 A set of two light receiving sections is arranged in a checkerboard pattern, and in each set, the above two light receiving sections are arranged in a column direction and are located in odd-numbered rows of adjacent columns. A solid-state image pickup device in which a signal from a light-receiving unit located in an even-numbered row and a signal from a light-receiving unit located in an even-numbered row are extracted as point-sequential signals in an arbitrary horizontal scanning period, and the signals in these horizontal scanning periods are sequentially output; Among the light receiving sections, every other row is supplied with full-color transmitted light of the image of the subject, and among the remaining every other row, every other one is supplied with the first primary color light of the image of the subject. It also has a color separation filter that supplies second primary color light of the image of the subject to the remaining one, and a delay means for one horizontal period, and a first signal of the all-color transmitted light from the solid-state image sensor. A point sequential signal of the second signal of the first primary color light, a third signal of the second primary color light, and a point sequential signal of the first signal are extracted every horizontal scanning period, and this line is A sequential signal is supplied to the delay means, the line sequential signal and the output signal of the delay means are supplied to first, second and third sampling and holding circuits, and the first, second and third sampling and holding circuits A solid state color imaging device configured to obtain synchronized first, second and third signals from a circuit.