JPS61167296A - Solid-state color image pickup device - Google Patents

Abstract

PURPOSE:To simplify the circuit, to reduce the size and weight and to lower power consumption by extracting brightness signal component and modulated color signal component obtained by rectangular modulation of carrier waves with phase difference of pi/2 by two different chrominance signals from a solid-state image pickup element. CONSTITUTION:The light from a lens 21 is passed through a color filter 22 to form an optical image on a solid-state image pickup element 23. The element 23 is driven by pulses from a pulse generator 24 and electrical signals corresponding to the optical image are amplified at 26. After gamma correction, the outputs on lines n and n-1 are coupled to contacts (a) and (b) of switches SW28 and 29 to be introduced to a summation circuit 30. The signal taken at a movable terminal C is introduced to a subtracting circuit 31. Brightness signal components are separated in the circuit 30, amplified at 32, passed through LPF33 and inputted as brightness signals Y to a summation circuit 34. The carrier color signal component is separated in the circuit 31, amplified at 35, passed through BPF36, summed with sub-carrier signals at 37 and introduced as carrier color signals into a circuit 34. In the circuit 34, signals Y, C and color burst signals are mixed together and NTSCTV signals are outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a solid-state color imaging device using one solid-state imaging device.

[Technical Background of the Invention] Conventionally, this type of solid-state color imaging device (single-chip color camera) has no burn-in or image distortion, has low afterimages, and consumes very little power, and is also small and lightweight, making it easy to handle. It has advantages such as In such a solid-state color imaging device, color separation is performed by providing an optical color filter as shown in FIG. 11 for each light-receiving unit of the solid-state imaging device.

What is shown in Fig. 11 is a so-called Bayer array color filter.
It is. Green filters G are arranged in a checkerboard pattern with the phase changing every horizontal row, and red filters R and blue filters B are alternately arranged between these green filters G every horizontal row. . Note that in this color filter, two pixels in the vertical direction have the same color due to interlacing of television signals.

FIG. 12 is a block diagram showing an embodiment of a signal processing circuit of a conventional solid-state color imaging device of this type.

The light collected by the imaging lens 1 passes through a color filter (identical to the one shown in FIG. 11) 2 and then passes through a solid-state imaging device (
For example, the image is formed on a charge-coupled image sensor) 3. The signal corresponding to the optical image outputted from the solid-state image pickup device 3 is amplified to a predetermined level by an amplifier 4, and then processed by a one horizontal scanning period (TH) delay line 5 and a color separation circuit 6 to produce red, red, green.

It is separated into R, G, and B signals, which are three primary color signals of blue. These R, G, and B signals are input to the process and matrix circuit 7, where they undergo gamma correction and white balance adjustment, and are converted into a luminance signal Y and two color difference signals (R-YL), (B-Y
I-). however.

Y is a low frequency component of the luminance signal. These two color difference signals (R-Y, ), (B-Y, -) are input to a modulation circuit 8.9, and a 3.58M
A subcarrier signal of H, is input through the phase circuit 11,
A 3.58 MH subcarrier signal is directly input to the modulation circuit 9. Therefore, the above subcarrier signal is transmitted to the modulation circuit 8.
, 9, color difference signals (R-YL), (B-Y, -)
Therefore, orthogonal modulation is performed. Modulated signal output from modulator 8.9 and process.

Luminance signal Y output from matrix circuit 7 and terminal 1
The color bar and strike signals supplied from 2 are sent to the adder circuit 13.
The signal is inputted to the input terminal 14 and subjected to addition processing, and an NTSC signal, which is one of the standard television signals, is extracted from the output terminal 14.

[Problems with Background Art] By the way, in the conventional solid-state color imaging device as shown above, after color separation is performed to obtain three primary color signals G, R, and B, there is a process of processing these signals.

The circuit configuration from the Rix circuit 7 onward until the NTSC signal is obtained is exactly the same as the circuit configuration of a color imaging device using a conventional image pickup tube. Therefore, even though a solid-state image sensor is used as an image sensor, it is not possible to take full advantage of the major features of solid-state color image sensors, such as low power consumption, small size, light weight, and ease of handling. -3= There were problems.

Furthermore, in the color filter array shown in Fig. 11, although vertical correlation is used to improve the horizontal resolution of the G signal, which is the main component of the luminance signal, the green filter G is originally arranged only in a checkered pattern. Since it does not exist, the band in the diagonal direction is narrow □, and there is a drawback that false signals called moire are likely to occur for subjects with diagonal lines. Furthermore, in the color separation circuit 6, the three primary color signals G, R, and B are separated by a sample and hold circuit, but the number of pixels in the horizontal direction is approximately 80.
When the switching time is set to 0, the switching time becomes as fast as about 70 ns, and the disadvantage that signal processing delay, switching noise, etc. associated with the switching operation adversely affects image quality becomes noticeable. Therefore, if an attempt is made to correct these adverse effects, the circuit configuration becomes even more complicated, and there is a problem in that the advantages such as small size, light weight, and low power consumption cannot be expected at all.

[Objective of the Invention 1] In view of the above-mentioned drawbacks, the object of the present invention is to provide a solid-state color imaging device that has a simple circuit configuration, is compact, lightweight, can be expected to have low power consumption, and can obtain -4= high-quality color images. It is about providing.

[Summary of the Invention] The present invention provides a solid-state imaging device that outputs a luminance signal component and a modulated color signal component obtained by orthogonally modulating carrier waves having phases different from each other by π/2 using two different color difference signals, and a solid-state imaging device. a luminance signal extraction means for extracting a luminance signal component from a signal output by the element; a color signal extraction means for extracting a modulated color signal component from a signal output from the solid-state image sensor; By using a solid-state color imaging device, the solid-state color imaging device is equipped with a phase adjustment means for making a television signal of a brightness, and a television signal generation means for generating a television signal from a luminance signal component, a color signal component, and a color burst signal. ．． This aims to achieve the above objectives.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a 111 diagram showing an embodiment of a solid-state image sensor (<CCDm image device) used in a solid-state color image sensor of the present invention. In this example, the CCD image sensor used is one in which, for example, 500 pixels are arranged in the vertical direction and 800 pixels are arranged in the horizontal direction. one vertical transfer CCD2
One light receiving element 23 corresponds to the light receiving element 2.
The charges accumulated in C0D3 are sent to the vertical transfer C0D211 via the readout gate 221. Similarly, the charge accumulated in the light receiving element 24 is sent to the vertical transfer CCf) 212 via the readout gate 222, and has a similar structure. Vertical transfer CCD211, 212
The charges sent to are sequentially transferred in the vertical direction using the horizontal blanking period. These vertically transferred charges are transferred to the first gate via gates 311, 312...
horizontal transfer C0D32. At this time, the parallel transfer gate electrode 34 is opened, and the electric charge is sent to the second horizontal transfer CCD 33 using the potential difference between the first horizontal transfer CCD 32 and the second horizontal transfer CCD 33.

Thereafter, the parallel transfer gate electrode 34 is closed, and the charges of the next line are vertically transferred to the first horizontal transfer CCD 32 via the gate electrodes 311, 312, . . . . next.

The charges of the horizontal transfer CCDs 32 and 33 are simultaneously transferred horizontally, and the signal charges are taken out from the output sections 35 and 36. As a result, the charges accumulated in the two vertically adjacent lines of light receiving elements as described above are simultaneously read out from the output sections 35 and 36. In this case, due to television interlacing -)'
> and (n, -1), n and (n+1), etc., and in even fields, line (n-
The signal charges are read out by shifting the combinations such as 1> and n, (n+1) and (n+2>...).

Here, the M4 color filter is arranged, for example, as shown in FIG. 1, and the basic repeating unit is 2 rows x 4 columns. That is, in the first horizontal scanning row, a magenta color (hereinafter referred to as M (+)) filter 23, a cyan color (hereinafter referred to as Cy) filter 2A, a green (hereinafter referred to as G) filter 2
5, yellow (hereinafter referred to as Y'e) filters 26 are arranged at a period of 4 pixels, and in the second horizontal scanning row, the phase of the four pixels in the first horizontal scanning row is shifted by π, and the G filter 27, '1/ e
The filter 28, the Mg filter 29, and the Cy filter 31 are arranged in this order at a four-pixel period. In subsequent horizontal scanning lines, these two horizontal lines are repeated in sequence.

FIG. 2 is a circuit block diagram showing an embodiment of the solid-state color imaging device of the present invention. The light collected by the imaging lens 21 passes through a color filter 22 and is spatially modulated, and then forms an optical image on a solid-state imaging device (CCD imaging device) 23 . The CCD image sensor 23 is driven by a drive circuit 25 based on pulses from a pulse generation circuit 24, and outputs an electrical signal modulated in accordance with the optical image to an amplifier 26. The two-line output signals amplified to a predetermined level by the amplifier 26 undergo gamma correction in the gamma correction circuit 27, and then
The output of line n is applied to terminal a of switch 28.29, and the output of line (n-1) is applied to terminal A of switch 28.29. At the same time, the output signals of lines n and (n-1>) are input to the adder circuit 30. Also, the switches 28 and 2
The signals taken out from the movable terminals C of 9 are input to the plus side and minus side terminals of the subtraction circuit 31, respectively. The addition circuit 30 separates the luminance signal component, and the subtraction circuit 31 separates the carrier color signal component.

Also, the movable terminal C of the switch 28 is switched to the a side and the nth
When selecting a line signal, the switches 28 and 29 are switched so that the movable terminal C of the switch 29 is switched to the terminal side and the signal on the (rl-1>line) is selected.

The luminance signal component output from the adder circuit 30 is amplified to a predetermined level by an amplifier 32, and then passes through a low-pass filter (L, P F ) 33 to remove unnecessary components, resulting in the final luminance signal Y. and is input to the adder circuit 34. However, the cutoff frequency of LPF33 is horizontal 800 pixels C
7,16M1- which is the Nyquist frequency of the CD image sensor
It is possible to expand up to 12. The carrier color signal component output from the subtracter 31 is amplified to a predetermined level in step S35, and then passed through a band pass filter (BPI).
In step 36, the band is limited, and unnecessary parts are removed, resulting in an I signal, which is input to an adder circuit 37.

Since this adder circuit 37 receives a 3.58MH signal with a fixed imaging width and phase from a terminal 38, this circuit adjusts the white balance of the primary color feed signal component input from the BPF 36. The final general color transmission signal @C is output from the adder circuit 37 to the adder circuit 34. The adder circuit 34 mixes the luminance signal Y from the 1PF 33, the carrier color signal C from the adder circuit 37, and the color burst signal input from the terminal 39, and outputs a type of television signal from the output terminal 40 of the adder circuit 34. A certain NTSC signal is obtained.

Next, the operation of this embodiment will be explained. The output signal V (t) obtained by amplifying the electrical signal obtained from the CCD image sensor 23 to a predetermined level by the amplifier 26 can generally be expressed as in the following equation.

However, in FIG. 1, magenta Mg and cyan Cv.

The signal charge generated when each of green G and yellow Ye occupies 41 light receiving elements is V14σ.

Vc"v, VG, and vve are not expressed as j'.

Then, in the (n-1> line of FIG. 1), an output signal Vn-1(t) as shown below is obtained.

Vn-1(t)-1/4 (Vh 1 Vcy-+-■G
+Vye)+1#r((V)10-VCV-VG+
,vye) cos? /St ten(VH(++VcV
-VG -VVe) sin ySt) ・(1) nth
On the line, an output signal Vn(t) as shown in the following equation is obtained.

Vn(t)=1//l (VH(1+VCL)VG
+VVe)-1/l(VHg-Vcy-VG +VVe
) CO3J4jst-1-(VHL)-vcy-VG
-VVe)sin? /at) ・(2) Here,
WS indicates the spatial modulation angular frequency, and the number of pixels in the horizontal direction is 8.
In the case of 00 pixels, '! 7s/2π is 3.58M+-1,
, becomes. It should be noted that, as modulation components, only the fundamental wave component of 'w''S is treated, and harmonic components are omitted.

FIG. 3 is a diagram showing an example of the spectral characteristics of each pixel MO, 'Cy, G, and Ye shown in FIG. 1, and the spectral characteristics are determined by the following two conditions. First, the first
The condition is that the following equation is satisfied when the subject is achromatic at the color temperature of the reference illumination.゛VHo-VG eyes Vcy-V ve...---(3)
The second condition is also under the color temperature of the reference illumination (1).

The DC signal component term in equation (2) is (VHo+Vcv+
VC + Vye) is made to be the spectral characteristic of the luminance signal Y,
Also, it is the first term of the modulation color component (VHo-Vcy-VG+
Vy'e) is the spectral characteristic of the color difference signal (R-Y, ), and the second term (VH(]]+Vcy-VG-Vy
The purpose is to make e the spectral characteristic of the color difference signal (B-Y,). In fact, Mo, Cv, G.

When the spectral characteristics of Ye are set as shown in FIG.

The DC signal component (VH (++'V
(: V + Vye), the modulated color signal component (VHO-VcV-VG + Vye) shown in FIG. 4(B), and the modulated color signal component (VHo+VYe) shown in FIG. 4(C)
cV-VG-VVe) are very close to the ideal spectral characteristics of the NTSC luminance signal Y, color difference signal (RYc), and (B-Y, -'), respectively. Therefore, by rearranging equations (1) and (2) according to the above conditions, they become as follows.

Vn-1(t)-kV Y+ kc ((RYL)
CO3VS [+(B YL ) sin m5t)
−(4)Vn(t)=ky Y−kc ((R−Y+
-) cos 2I7St+ (B-Y+->si
n Mt) --・----C5>Here, ky, kc
is a constant. By the way, the output signal of the image sensor 23 (CCU') itself is a luminance jα(i'j ``''r component.

The two color difference signal wings (R-Y, i, l-'Y'l) each have a phase lj of π/2, 3, ,'i8M I
It is in a multiplex format with a carrier color signal component obtained by orthogonally modulating a general transmission wave having a frequency of t. However.

In the NTSC system, the subcarrier phase is 4 as shown in Figure 5.
In order to return to the original state in the field, the phase of the output signal obtained from the CCD 1fH image element 23 must be adjusted.

In this phase adjustment method, as can be seen from equations (4) and (5'), the phase of the four modulated color signal components is inverted every horizontal scanning period (1H), and on the contrary, the luminance signal component, which is a DC component. This is done by skillfully taking advantage of the fact that they are in phase. Here, assuming that the color filter 22 shown in FIG. 1 has a color filter arrangement as shown in FIG. 6, the switch 28 selects the line in the first field of the first frame, and the switch 29 selects the line 2. Select. In the next scanning line, switch 2B selects line 4 and switch 29 selects line 3 to invert the phase. Similarly, 2 every 1H
The two switches 28 and 29 are switched. In the next first frame and second field, the 264th scanning line in Figure 5 will be obtained from lines 2 and 3 in Figure 6, but since this is an even numbered scanning line, it continues from the first field. Resetting switches 28 and 29 at this point, switch 28 selects line 2 and switch 29
switches line 3 to the selection number. Thereafter, as in the case of the first field, the two switches 28 and 29 are switched so that the phase of the carrier color signal is inverted every 1H.

Next, in the second frame and first field, the phase of the carrier color signal of each scanning line is 180 degrees different from that in the first frame and first field. Here, since the total number of scanning lines in the first frame is 525, which is an odd number, the switch operation continued from the previous frame will naturally continue as it is, with switch 28 selecting line 2 and switch 29 selecting line 1, respectively. The phase is reversed.

After R, in the second frame and second field, the switch operation is partially reset in the same way as in the first frame and first field, switch 28 selects line 3, and switch 2
9 selects line 2. In this way, switch 28 and 29 are basically switched every 1H,
By resetting the switch switching operation 10 at the beginning of the second field in the same frame and inverting the lines selected by each switch 28 and 29, the phase of the modulated color signal can be changed in 4 fields as in the NTSC system. It will return to its original shape. Note that the switches 28 and 29 are connected to the pulse generation circuit 24.
controlled by switching pulses generated from the

In this way, as can be seen from equations (4) and (5), the luminance signal components that are synchronized within one day are removed by the reduction circuit 31,
The output of the subtraction circuit 31 becomes a color signal in the same format as the carrier color signal of the NTS C system. The carrier color signal output from the subtraction circuit 31 is amplified by the amplifier 35, and is then amplified by, for example, 3.58M1-1. The band is limited by the BP'F36 which has a passband of ±0.5M)l, and among the signals that are not color signal components among the output signals of the CCD image sensor 23, the phase is inverted every 1H and subtracted. Noise components that have passed through the circuit 31 are removed. In the adder circuit 37, the carrier color signal from the band pass filter 36 and the 3, 58 M1-1 . The white balance is adjusted by the signal. Note that in the addition circuit 37.

Two 3s with the same phase as a subcarrier with a certain imaging width
．． Since the operation equivalent to adding the 58M+-1z signal is performed, the white balance adjustment described above is performed. In the end, as mentioned above, the final color signal C is output from the adder circuit 37.
is obtained.

On the other hand, a part of the output signal for two lines which has been gamma corrected by the gamma correction circuit 27 is added to the addition circuit 30.

The signal component added to the adder circuit 30 is I5 modulated color signal Y.
Since the phase of the two components is inverted every 1H, the color signal component is removed and only the luminance signal component is obtained. This luminance signal component passes through the LPF 33 and unnecessary components are removed.
This becomes the final luminance signal Y. The adder circuit 34 mixes the luminance signal Y, the carrier color signal C, and the color burst signal input from the terminal 39 to produce the final NTSO signal 40.

According to this embodiment, the output signal of the CCD image sensor 23 itself is multiplexed by a luminance signal component and a modulated color signal component obtained by orthogonally modulating a carrier wave whose phase is shifted by π/2 with two different color difference signals. Because it is composed of signals,
In terms of structure, it is possible to classify the luminance signal component and the carrier color signal component using only a simple signal processing circuit including an addition circuit 30 and a subtraction circuit 31. Therefore, it is possible to obtain high-quality images without switching noise generated from sample-and-hold circuits for color separation, which were conventionally required.
The color signal detection section and the orthogonal modulation section are not required, the circuit can be simplified, and small size, light weight, and low power consumption can be realized.

Furthermore, in this embodiment, since the spectral characteristics of the color filter 22 are selected as shown in FIG. 3, two color difference signals @ (RYc), (B-Y,
) becomes zero, which has the great advantage that no modulated color signal is generated. For this reason.

No matter what kind of change occurs in the achromatic color in the vertical direction, the color difference signal is always zero, making it possible to completely suppress the occurrence of vertical false signals, which has been a major problem in the past. Also, the fact that the modulated color signal becomes zero for an achromatic object means that the color filter 22
In other words, since the luminance signal is equivalent to a black and white CCD image sensor, false color signals caused by modulated color signals can be suppressed, and the performance of the luminance signal can be brought out to the limit of the performance of the monochrome CCD image sensor. Furthermore, it has the advantage that there is very little coloring in afterimages, smearing, or blooming. Also, since the spectral characteristics of each pixel are set as shown in Figure 3, the color difference signal (R-YL), (
The spectral characteristics of the luminance signal Y (B-YL) and the luminance signal Y are very close to those of NTSC, and excellent color reproducibility can be obtained by appropriate gamma processing. Furthermore, although the conventional color filter shown in Figure 1 uses vertical correlation to improve the horizontal resolution of green, which is the main component of the luminance signal, the green pixels originally exist only in a checkered pattern. Therefore, the band in the diagonal direction is narrow, and false signals called moiré are likely to occur with respect to diagonal lines of the subject. However, in the color filter of this embodiment having the characteristics shown in FIG. 3, the green passage area is the entire surface, and as a result, the occurrence of moiré can be significantly reduced. Furthermore, since the color filter having the characteristics shown in FIG. 3 is a complementary color system, it can have a sensitivity superior to that of a conventional primary color system.

FIG. 7 shows another example of the color filter 22 shown in FIG. 1. The color filters that determine the spectral characteristics of the light-receiving element are not limited to those explained in FIGS. , D if the color filters having the spectral characteristics are repeated. That is, the horizontal scanning signal V (t) in this case is as shown in the following equation.

V(t)=1/4 (A+B+C+D)+1/π((
A-B-C1D) CO3 escape [+ (A+B-C=
D) sin Vst) ・(6) Therefore, (4), (
By comparison with equation 5), the term (A-B-C+D) in equation (6) becomes the (RY,) signal, and the term (A+B-〇-D) becomes (F3-YL). A, B, C as the number
, D, and the terms (A + B + C + D> are equally in phase in the two vertical lines, and furthermore, (A
A, so that the phases of the term +D> and the term (A0B-C-D> both have equal absolute values and opposite phases in two vertical lines)
The spectral characteristics of B, C, and D are determined.

By using such a color filter in the circuit shown in FIG. 2, it is possible to obtain a solid-state color imaging device that can perform the same operation as the previous embodiment.

In addition, if the horizontal repetition period of the color filter is 3 pixels, the horizontal scanning signal ■ ([) is calculated by the following formula % formula % [In this case, as in formula (6), the term (A + B + C) (A
/2- B + C/2) and (A-(j) are (4
), if the spectral characteristics of A, B, and C are determined to take values corresponding to equations (5), the circuit shown in Figure 2 can be used even if a color filter with a horizontal repetition period of 3 pixels is used. NTS
C signal can be obtained. However, the number of horizontal pixels of the CCD image sensor is 600. Furthermore, in the previous embodiment, an interline CCD image sensor with simultaneous two-line readout as shown in FIG. Imaging tree level C 1 (I.

In addition, the solid-state image sensor shown in Fig. 1 has a structure in which one vertical transfer C0DSIFl is combined with one light receiving element, but in addition to this, one vertical transfer C0DSIFl is combined with two vertically oriented light receiving elements. The transfer COD may have a corresponding structure, and FIG. 8 shows an example of a color filter arrangement having such a structure. In the solid-state image sensor equipped with the color filter shown in FIG.
Addition and simultaneous readout of 4 is performed, and then addition and simultaneous readout is performed in the following order. In the even field, the combination of additions is changed for interlacing, and lines 2 and 3 are first added and read out simultaneously, then lines 4.5 are added and read out simultaneously, and then added and read out in this order. At this time, the horizontal scanning signal read out is similar to those shown in equations (4) and (5), where the luminance signal and the modulated color signal are in a frequency interleaved relationship, and the two color difference signals in each modulated color signal are According to the company, the phase of the carrier waves is shifted from each other by π/2 (/l), which is the same as that of equation (5). 1st
The difference between the color filters shown in Fig. 8 and Fig. 8 lies in the composition ratio of G, R, and B in the luminance signal, which is a DC component, and this can be adjusted by means of controlling the spectral characteristics of the color filter. can.

Furthermore, although the charge storage method of the CCD image pickup device in the above embodiment was a field storage method, a frame storage method could also be adopted, and FIG. 9 shows another example of the color filter in this case. It is a diagram. Further, FIG. 10 is a block diagram showing another embodiment of the signal processing circuit of the solid-state color imaging device when the color filter shown in FIG. 9 is used. In FIG. 10, C is equipped with the color filter 41 shown in FIG. 9, which spatially modulates the light condensed by the imaging lens 21.
The CD image sensor 42 has a structure in which one vertical transfer COD corresponds to two vertical light receiving elements, and has one horizontal transfer COD. This CCD image sensor 42
Since the driving method is frame accumulation, in FIG. 9, lines 1.2°, . . . are read out sequentially in odd fields, and lines 264, 265, .
are read out sequentially. The signal read out in this way is (
It has the same format as Equation 4) or (5). The signal read out from the CCD image sensor 42 is amplified to a predetermined level by the amplifier 26, then subjected to gamma correction by the gamma correction circuit 21, and further passed through a low-pass filter (L P F ).
43 and a band pass filter (BPF) 44. The low-pass filter 43 is a 3M1-1. It has a cutoff frequency of , and separates only the luminance signal component from the input signal and outputs it to the amplifier 32. amplifier 32
The luminance signal Y amplified to a predetermined level is input to the adder circuit 34. On the other hand, the bandpass filter 44 is 3.
5A: It has a passband of t-0, 51+71H2, and divides the modulated color signal component #1 from the input L; >: and outputs it to the amplifier 35 by 1J. The modulated color signal component amplified to a predetermined level by the amplifier 35 is input to an inversion circuit 45 and a buffer 46.

The inversion circuit 45 performs an operation of inverting the phase of the input signal component by 180 degrees, the buffer 46 performs an operation of adjusting the output level of the input signal component to that of the inversion circuit 45, and each output signal is output from the switch 41. terminals a, b
is applied to The movable terminal C of the switch 41 is switched to the terminal a and the terminal A side by a switching pulse generated by the pulse generating circuit 24 at a timing such that the modulated color signal component matches the phase of the NTSC subcarrier. Therefore, the movable terminal C of the switch 41 eventually outputs a modulated color signal component whose phase matches that of the NTSC subcarrier, and this is input to the adder circuit 31. The switching frequency of switch 47 is determined by the color filter arrangement shown in Figure 9. □15
It becomes H2. Since a signal having the same phase as the subcarrier of 3.58 MHz is applied to the adder circuit 31 from the terminal 38, the white balance of the carrier color signal component input from the switch 47 is maintained, resulting in a complete carrier color signal C. and is input to the adder circuit 34. The adder circuit 34 mixes the luminance signal Y input from the amplifier 32, the carrier color signal C, and the color burst signal input from the terminal 39, and outputs an NTSC signal from the output terminal 40.

This embodiment also has the same effect as the embodiment shown in FIGS. 1 and 2.

[Effects of the Invention] As described above, according to the solid-state color imaging device of the present invention, the luminance signal component from the solid-state imaging element has a phase of π/
By directly extracting the modulated color signal components obtained by orthogonally modulating two different carrier waves with two different color difference signals, the circuit configuration is simplified, and the system achieves compact size, light weight, and low power consumption, while producing high-quality color images. There are benefits to be gained.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a solid-state image sensor used in a solid-state color imaging device of the present invention, FIG. 2 is a circuit block diagram showing an embodiment of the solid-state color imaging device of the present invention, and FIG. The figure shows the spectral characteristics of each pixel of the color filter array mounted on the CCD1it image element shown in Fig. 1, and Fig. 4 shows the luminance signal and color difference signal obtained from the circuit shown in Fig. 2. A characteristic diagram showing the spectral characteristics. Figure 5 is a diagram showing the phase relationship of sub-primary transmission in the NTSC system. Figure 6 is a diagram showing an example of the arrangement of color filters shown in Figure 1. The figure shows an example of characteristics when a 4-pixel cycle C color filter is repeated in the horizontal direction, and FIG. 8 shows another embodiment of the color filter used in the solid-state color imaging device of the present invention. FIG. 9 is a diagram showing still another embodiment of the color filter used in the solid-state color imaging device of the present invention, and FIG. 10 is a circuit block diagram showing another embodiment of the solid-state color imaging device of the present invention. Figure 11 is a diagram showing an example of a conventional color filter arrangement.
FIG. 2 is a block diagram showing an example of the circuit configuration of a conventional solid-state non-porous imaging device. 21...Imaging lens 22.41...Color filter 23.42...CCD image sensor 25...
・Drive circuit 27... Gamma correction circuit 28,2
9.47...Switch 30.34.37...Addition circuit 31...Subtraction circuit 33.43...Low pass filter 36.44...Band pass filter 45...Inversion circuit 46... Buffer agent Patent attorney Noriyuki Chika (1 idiot) = 2
7- ゑ夙ρ 翳l except -N FI ... MiυI cost ≦. Figure 7 Figure 8 Figure 9 &--Peno

Claims (1)

[Scope of Claims] A solid-state image sensor having pixels arranged two-dimensionally, and a signal read from the solid-state image sensor that is a luminance signal component and a color difference signal in which two carrier waves whose phases are different from each other by π/2 are different from each other. a color filter that optically modulates optical information imaged on the photosensitive surface of the solid-state image sensor so as to be composed of a modulated color signal component that is orthogonally modulated by a color filter; a luminance signal extraction means for extracting the modulated color signal component from the output signal of the image sensor of the solid-state image sensor; and a color signal extraction means for extracting the modulated color signal component from the output signal of the image sensor of the solid-state image sensor; and a television signal generating means for generating a television signal from the luminance signal component, the phase-adjusted modulated color signal component, and the color burst signal. A solid-state color imaging device characterized by: