JPS58179082A - Color image pickup device - Google Patents

Abstract

PURPOSE:To obtain a video signal of excellent picture quality, by separating the two output signals of a solid-state image pickup element and the 1H-delay output signal into four signals, limiting each maximum amplitude and obtaining red and blue color signals with a logical operation. CONSTITUTION:The output signal OH of a solid-state image pickup element 15 in which color filters are combined is delayed by a 1H delay line 16 by a time equivalent to a scanning line. The signal OH and a 1H-delayed signal 1H are applied to four gate circuits 17-20, and four signals are separated. In this case, a gate signal 21 is applied to the circuits 17 and 19, and a signal 22 having a 180 deg. phase difference to the signal 21 is applied to the circuits 18 and 20. Thus signals (a), (c), (b) and (d) are separated respectively. Then these signals are applied to limiters 23-26 with limitation given to each maximum amplitude. The output of this limitation is sent to arithmetic circuits 29 and 30. A blue signal is obtained from the circuit 29; while continuous red signals are obtained out of the output of the circuit 30 via an inverting circuit 31. Then a luminance signal Y is obtained from a gain control circuit 33.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image pickup device using a charge transfer image pickup device (hereinafter abbreviated as CCD).

Regarding the method of obtaining color television signals using a single image sensor, two types of filters, transparent and yellow, and transparent and cyan, are placed at positions connecting 1111 of the subject, and the red and blue signals are filtered into the sky II. There is a known method of frequency multiplexing the green signal and outputting 1119 from the image sensor.
In the method, the output of the image sensor is passed through a low-pass filter to obtain the luminance signal;

The red signal and the green signal are multiplexed and included in the output of the image sensor as a carrier wave component (hereinafter abbreviated as modulation component) determined by the spatial modulation θ frequency fIL, so they are extracted by a bandpass filter and the extracted modulation component is extracted. It is designed to further increase the red light and green light.

Conventionally, as a method of separating red and blue signals from modulation components, the red modulation component and the blue modulation component included in two scanned alKs have a frequency intersegmenting relationship. Two types of color filter arrays are selected, and the modulated components extracted by the sound range filter are delayed by a delay mal (hereinafter abbreviated as IH delay) that is incestuous with one horizontal scan, and the ill components of the two scanning lines are Regarding frequency interleaving, there is a known method to separate the red modulation component and the blue modulation component and demodulate their respective R#!4 components to obtain the red signal and the iI signal. xHj! In the past, a glass delay line was generally used.By the way, this '
The NN lath grinder uses a piezoelectric element to convert an input electrical signal into an ultrasonic wave, and the ultrasonic wave propagates through the glass.On the output side, the piezoelectric element converts the ultrasonic wave into an electrical signal again, delaying the signal. In this case, the propagation time of the ultrasonic wave in the glass is the time equivalent to one horizontal line.In the glass delay line, when this ultrasonic wave propagates through the glass, it causes unnecessary reflections and is output. The signal contains a signal (spurious signal) caused by this unnecessary reflection, and this has the disadvantage that the image quality of the red and blue signals is lower than that of K.

In addition, since the red signal and the blue signal are obtained from the modulation components of the two scanning lines, the phase with the luminance signal in the vertical direction is shifted by an amount of h scanning lines, and this phase-shifted signal is used as the two color difference signals. &
- When the T signal and B-T signal are formed, a false color difference signal is formed at the vertical edge portion of the image, resulting in false colors, and a vertical correlation error occurs at the vertical edge portion of the image where there is no vertical correlation. 2. The phenomenon of false red and green lights
This method has two essential drawbacks. In order to prevent the image quality from deteriorating due to these two drawbacks, the low-frequency component of the luminance signal for forming the color difference signal is formed by the luminance signal of two scanning lines, and the red signal, the blue signal, and the vertical It is necessary to obtain the low-frequency component of the luminance signal by obtaining the low-frequency component of the luminance signal by dispersing the phase in the direction, and at the same time form a vertical edge signal, and to suppress false red and green signals due to the vertical correlation error with this vertical error (No. 41). However, in the past, in order to obtain the luminance signals of the two scanning lines, it was necessary to use a separate KIH delay line to delay the luminance signals, which had the disadvantage of complicating the apparatus.

The present invention has been made in order to eliminate the above-mentioned drawbacks.
The purpose is color photography SI with a simple configuration and no deterioration in image quality.
! The goal is to provide equipment.

According to the present invention, video signals corresponding to the golden light and green light components are obtained alternately in the scanning line direction, and video signals corresponding to the cyan light and yellow light components are obtained alternately in one scanning direction. A video signal corresponding to the golden light and green light components and a video signal corresponding to the cyan light and yellow light components are transmitted every scanning line.
li # A solid-state image sensor configured to obtain the following,
From the IH delay line that delays the output signal of the solid-state image sensor by one horizontal scan allK4tl, the output signal of $11 that is not delayed, and the output signal of N2 that is delayed by the IHjl Sagi line described above. In the horizontal scanning period of $1, the video signals corresponding to the golden light and green light O components are separated from the first output signal. It separates the video signals corresponding to the light components and prevents IP spread.
In the horizontal scanning period of J12, in which video signals corresponding to cyan light and yellow light components are separated from the output signal of the second output signal, video signals corresponding to gold light and green light components are separated from the delayed second output signal. Each part separates from the other, and
It is characterized by comprising at least a matrix circuit for forming a video fII signal corresponding to the red light and blue light components from the video signal corresponding to the cyan light and yellow light components of the green light and the cyan color light component separated from each other. Force 2 - an imaging device is obtained.

The present invention will be explained in detail below using the drawings.

FIG. 1 shows an example of the arrangement of 1Iiii elements of the present invention. As shown in Fig. 2, this pixel arrangement consists of transparent #4 (b) and cyan (c) which are inclined at an angle such that the phase changes by 180 @ with respect to the perpendicular direction of the Kj image.
The red signal is spatially modulated by a filter similar to Ja, and similarly K
The blue signal is spatially modulated by a filter made of transparent and yellow (Y, ) whose phase is constant for each scanning line in the vertical direction of the ij image.

ill: In Figures 1 and 2, the pixel designated by the symbol 11 is transparent, and the pixel designated by the symbol 4 has cyan (q) and ★曵) overlapping each other, so it is a festival that can pass through both filters. . The code entry is cyan (CY), and the code 14 is yellow (
Y, ).

In Figure 1111, W and Ennichi appear from the scanning line of Ayame Scanme (Karasuko L\kan...), and cyan (
(Y) and (Y) are alternately added to each pixel. Third
The figure illustrates how to separate the red light and the red flag. Referring to Figure 1 and Figure 3, the output signal of the solid-state image sensor has a delay time corresponding to one horizontal scanning period.
When the jll edge line is delayed, when the output signal of ``m@'' is obtained from the solid-state image sensor, the output signal of 1st -l@ is obtained from the IHjl sagi. Joy m (I) from solid-state image sensor
The output signal of I is separated into two signals, transparent and fair, using two gate circuits. Similarly, the a-1@()-th output signal from K 1 [j1 wind- is separated into two signals of cyan (CY) and yellow α·) by opening two gates.

FIG. 3a S-4 shows the output signals separated by the four gate circuits. A and b indicate signals separated from the output signal of the solid-state image pickup device, and C and - indicate signals separated from the IHjl凰-〇 output signal.

In the figure, symbols with a symbol “” indicate signals without a “”.
This indicates that it is M-carrying nine signals.

These four dirt circuits are used in the next scanning period, that is, in the scanning period in which the 1% + 1410th output signal of JIII garden is obtained from the solid-state image sensor, the gate circuit that separated the transparent (wl) signal at the S@th Gate 1 separates the cyan (CY) signal at 5+l@, and the edge (Gl) signal at S@, and separates the tribute (Y town) signal at S+1@. Similarly, the cyan (CYI') signal is separated from the output of the IH Haruka line at the S@th, and the friend gate circuit separates the transparent (Y) signal at the n+1@th, and the yellow (CYI') signal is separated at the n+1@th.
The 5th+1st @
Now, the #(GI') signal is separated. From then on, each scanning line is K.
This will be repeated.

The following equation is calculated using the four signals 1 to b shown in the next KIE3 diagram.

(1) −* + c−b−d 情1 ” a 10d −b −t The calculation of equation (1) is in Iris - (1) “W1 + Cy @ 01 − Y * @ JII calculation + l round, (1) - Paste +w, '-y・I Gl' and fx v te s@, s+111 both Ktll=W+C, -G -T
h. Transparent - 2 yellow (Ye) and cyan (CY) are respectively W - red (2) 10 m 40 blue - Y @ ■ red (2) 10 fair days CY = 4 fair days (8), so (of type 0 The calculation becomes 5 as follows.

+1) ヰW +C, -G -re ヰR+2G+2B-11-2G 21 That is, by performing the calculation of equation (1), a green signal can be obtained. Working in the same way, in S@ -...-13J -W, + y・, / c
, cY6's+1@ is "1 God qs 10GI Y
e1 %', so (2)-2R+2G+l-20-B =2---(%-) (2)=20+B-2R-2G-B =-2---(arithmetic+1@) That is, (2 ) By performing the calculation of the formula, the R and -R flaw signal scanning lines can be obtained alternately, so by reversing the polarity of the -l signal, a continuous red signal can be obtained.

Diagram 4 is a double diagram showing the Jl[o negative flow side of the present invention.
In the figure, the output of the solid-state image sensor combined with the color filter (hereinafter abbreviated as OH signal) is the IH delay line 16.
The time delay is reduced to one scanning line. OH signal and 1)
The good signal (hereinafter abbreviated as IH signal) which has been extended by ijl is applied to four gate a-paths 17-20. Gate circuit 17
20 separates four signals from the OH signal and the IH flaw signal as detailed in FIG. That is, the gate signal (2) is applied to the gate circuit 17 so as to separate the signal of JI31IIA, and this gate signal (3) is simultaneously applied to the gate circuit 19, and the signal of the iris 3 (C) is separated. - The gate signal n having a phase difference of 1800 with respect to the gate signal ga is added to the gate signal tgsriab and d, respectively.
The signals are separated and obtained.

The separated four signals 1-d are then applied to limiters n-j. The limiters 23-26 have signals a-d, respectively.
limits the maximum amplitude of

Figure S (IL+, (e)) explains the operation of the limiter n-.

jls Figure IJLI is transparent (b) obtained from a solid-state image sensor.

The amplitudes of the yellow (Ye), cyan (C,), and Ennichi signals with respect to the amount of incident light are shown. As mentioned in III, KW=
R+G 10B = Y*=R+G #CregG Since there are 10B, each swing is W>Y・,CY)G.

When the output of the solid-state continuous image element reaches point L, it becomes saturated, and thereafter the output does not increase even if the amount of incident light increases. Therefore, as the amount of incident light increases, [transparent color with a large output becomes saturated at point (l), then yellow (Ye) at point (2), cyan (-) at point (431),
The edge (6) is sequentially saturated at the point (4). By the way, when the amount of light incident on a pigeon coop where the output saturation point is the same L point for all four outputs exceeds point (1), the above-mentioned red signal and green signal are obtained by calculating the rl> equation and equation (2). An error occurs in the input light amount, and the calculation results of the formula (rounding +1), which becomes w!h-CYmlIG when the (turning) point is reached, are both zero.

In other words, when the amount of incident light exceeds point (1), the magnitude of the red and green signals decreases even though the amount of incident light increases.
When the amount of incident light is (4) on the point board, the red and green signals cannot be obtained at all.The limiter n-grave prevents errors in this calculation. , the magnitudes of the four signals do not increase after that.The Ii@ of the four signals is limited by each magnitude from 4 to -.Therefore, this amplitude is -
If you calculate equations (1) and (21) with a signal limited to ~14, the amount of incident light will be (1) When on the dot plate, the red and green signals have a constant magnitude determined by the value of - to -011 The number is iris 5
This prevents the phenomenon of zero, as in the case of the pigeon coop in Figure tjIJ.

Figure 1I114. ξ Tsuta n Kushin is the 3rd Kakubata ~ dK As shown, the output of Togai Gate 1 17 ~ 2g differs for each scan line shot, so the magnitude that limits the amplitude is set to the signal for each scan line shot. Let's make a change. The control signal r and addition are signals for this purpose.

That output is then added to the operation 1, 4, and concave. Arithmetic circuit 4 performs the arithmetic operation of the above-mentioned il1 formula to obtain a green signal. The arithmetic circuit (component) similarly performs the calculation of equation K(2), and its output alternately provides the mouse and -R signals.The inverting circuit 31 inverts the polarity of -R to obtain a continuous red signal.

The control signal strength is controlled so that the inversion 1 path 31 is inverted/non-inverted for each scanning line.

The brightness signal Y is yellow (O obtained from the body image) (I use the signal as it is, but the edge as shown in IIK) is yellow (Ye).
) and shear y (C,), the light transmittance decreases, so the average eirin level of the % threshold in Figure 1 (API,) i homeward s + 1 the same average eirin level In order to prevent this, the gain control circuit shown in Figure 4 controls the magnitude of the green IG+ signal using the control signal tone to compensate for the decrease in light transmittance of the filter.

FIG. 6 shows the control signal reading, in which the gain control circuits W&O are configured to control only the amplitude of the green signal at %(6).

The cuff encoder black forms a composite cuff video signal from the luminance signal Y, the red signal 2, and the blue signal B.

By the way, in the embodiment described above, since the signal is formed using one signal, which is a single brightness signal, and one beam signal, there is a drawback that a false color difference signal is formed, as described in the explanation of the prior art example. A second embodiment of the invention eliminates this drawback.

Figure jI7 is a schematic diagram showing an example of JI2.

The structural overlaps indicated by symbols b to proverbs in the figure are the same constituent elements as those described in the diagram j14, and therefore their explanation will be omitted.

The two signals separated from the OH signal, the 1 signal and the b signal, are added together in an adder r to form a narrowband luminance signal. Since the b signal is a repetition of the image signal and the yellow (Y) signal as shown in Figure JII 3, the amplitude of the recording signal is adjusted to 41 by the gain control circuit in the same way as in the first embodiment shown in Figure 4. Control with. The control signal S is a signal for controlling the gain for each scanning, unlike in the first embodiment.

The OH signal and IH flaw signal are added together at the beginning to form a wideband brightness value button.

Color Encoder provides red light, green light, and narrowband**
A composite color video signal is formed from the signal Y and the broadband luminance signal Y.

The gs diagram is a schematic diagram showing Color Encoder's signal processing. Broadband luminance signal Y-1 passes through two p-bus filters, 44; Filters 45 and 46
, 47, and generates a low-frequency component of a luminance signal for forming a color difference signal. By subtracting the narrow band brightness fg1 YI from this low frequency component Y1, a first-order differential vertical edge signal is obtained. By subtracting the low frequency component YL from the wideband luminance signal Y, the mechanical power Y of Takuta is obtained. After the high frequency component Y1 and the vertical edge signal are added,
Add to the original low frequency component YL, green signal and red signal. If the magnitude of the signal to be added at this time is YL (Y), it is possible to emphasize the outline of two machine differential types in the horizontal direction, so they are added together.
Castle component Y and vertical edge signal are horizontal.

The size of each K is adjusted so that optimal contour enhancement is performed in both vertical directions.

The brightness signal, red light, and green light are then routed to Busses Enclosure 48.
, 49 and 50 respectively for gamma correction, white clip,
Processed with black clip and blanking mixture. Matrix circuits 51 and 52 form two color difference signals, RY signal and BY signal, from the luminance signal, red signal, and blue signal.

At this time, the low-frequency component YL of the luminance signal is formed from a wideband luminance signal created from the two scanning signals, so the vertical phase of image ii matches the red and blue signals, so it is a false color difference signal. is never formed. Color difference signals are modulated! 163 to produce a carrier color signal. Gain control (b) path 8 suppresses the magnitude of the carrier color signal with a vertical edge signal. As mentioned above, in the vertical edge portions where there is no vertical correlation, false signals are generated due to the correlation error of the red and blue signals Kfi, so the carrier color signal contains these false signals. The gain control circuit 8 suppresses the carrier color signal in the vertical edge portion, thereby suppressing false signals caused by this vertical correlation error.

Next, this carrier chrominance signal and the synchronization signal 5 are added to the 1 luminance signal to form a composite signal.

In addition, in the above explanation, as shown in Diagram 2, the yellow (α) filter was arranged vertically and the cyan (Cy) filter was arranged diagonally, but this is because yellow (Y・) and cyan (cY) '4I: It is exactly the same when the cyan (CY) filter is placed vertically and the yellow (h) filter is placed diagonally.
1 gives a green light.

[Brief explanation of the drawing]

Figures 1 and 2 show the force 2 used in the O color imaging device of the present invention.
- Schematic diagram showing the arrangement of filters, Figure 3 is a schematic diagram to explain the principle of operation of the present invention, $I4 Figure, Figure 5 4p
('') #Figures 6, 7 and 8 are schematic diagrams for explaining the embodiments of the present invention. In the figures,
U is a transparent filter, Omi is a green filter, 13 is a cyan (4) filter, 14 is a yellow (Ye) filter, 15 is a solid-state image sensor, 16 is an IH;! Line extension, 17, 18
, 19, 20 are gate paths, 21.22 is a gate signal, 24, 25, 26 are limiters, n, 28 are control signals, 6, 30 are operation (9) paths, 31 is an inversion gi#l! ,
The proverb is control number 1, north is gain control - path, λ is control signal, a is color encoder, a is composite power 2 - video signal, n is adder circuit, a is gain control circuit, iris is control signal, mallet is Addition circuit, 41 is a force 2-encoder, 42 is a composite color video signal, 44, 45, 46, 47 is a bass filter, 49, 50 is a purcess 1li1.
51 is a matrix subpath, 1 is a modulator, 2 is a gain control circuit, and 55 is a synchronizing signal. '\, 1 Figure Z Figure 3 Figure 2 L Yu 1'' 12 - Jd Now Ushi ヰ War Noah (H) Nofuna / (14) ηsu 2 (H) nsu 3
(H) Figure 5 Alone J! The figure of one person, Kodou Dai, et al.

Claims (1)

[Claims] 1. Video signals corresponding to golden light and green light components are obtained alternately in the scanning line direction, and video signals corresponding to cyan light and yellow light components are obtained alternately in the scanning line direction. and a video signal corresponding to the golden light and green light components and a video signal corresponding to the cyan light and yellow light acid component Ig are obtained one after another for each scanning line. , an IH delay line that lags in time corresponding to the output signal 7-horizontal scanning 1 of the four-body recording element, a first output signal that does not lag, and the above-mentioned IH.
From the two output signals of JIl and the delayed output signal of KLLN2, which are slow and slow, the eirin signal corresponding to the golden light and green light components are separated from the output signal of JIl, which does not delay. During the horizontal scanning period, the irises *a corresponding to the cyan and yellow light components are separated from the delayed 20 output signal, and the cyan and yellow light components are separated from the non-delayed irises 1 output signal. The video II and signal are separated! During the horizontal scanning period of j12, a separation circuit separates video signals corresponding to the golden light and yellow light oitt* from the delayed output signal of the irises 2, and separates the separated golden light, green light, cyan light, and yellow. A color imaging device having at least b in the red light and blue light components from the image corresponding to the light component. z jlThe golden light, green light, cyan light, and yellow light included in the first output signal are
A control circuit is used to generate a wideband luminance signal from the output of this control circuit, and to form a color difference signal from this broadband luminance signal. 2 - Imaging device according to Section M5311 of the Permit #I request, which is equipped with a video signal circuit that generates a low-frequency component of a luminance signal. 1 Add and combine the non-delayed first output signal and the delayed output signal of the irises 2 to form a broadband luminance signal, and create a low-frequency component of the luminance signal for forming a color difference signal from this broadband luminance signal. A color imaging device according to claim 2, comprising a video signal circuit. (Which of the video signals corresponding to the green t and 0 components of the two video signals separated from the signal of the compartment, the undelayed output signal of irises 1 and the second output signal with j1 reduction)
A control circuit operates for each scanning line so as to control the output of the control circuit, and the output of the control circuit is separated from one of the signals and added to the other video signal. 3. The color imaging device according to claim 2, further comprising a video signal circuit that forms a luminance signal. 1 The video signal that is incestuous with the red light and blue light components formed from the full color light, green light, cyan light, and yellow light O component Km roaring video is the successor to the video signal II! 1rRI of each of the video signals corresponding to all color light, green light, cyan light, and yellow light components so that the output of the element can be obtained even in a saturated state of 11.
1lIiIl of the patent claim, which is equipped with a circuit that limits Il'! 1. The color imaging device according to item 1.