JPS6054590A - Color image pickup device with single plate - Google Patents

Abstract

PURPOSE:To obtain a color image pickup device with high resolution and few pseudo chrominance signals by installing two sets of filters which transmit two kinds of colored lights repeating by two picture elements in the horizontal direction, and arranging the filters with repetition in the vertical direction in such a way that these two sets of filters are shifted by one picture element. CONSTITUTION:In (n) scanning sections of the 1st field, signals formed by addition of two horizontal lines such as W+Cy, W+Ye, G+Ye, G+Cy... are outputted. Now, a luminance signal is denoted as Y, and when Y is approximated to Y=R+2G+B, the outputs become Y+B, Y+R, Y-B, and Y-R, and the signals are obtained which are modulated in such condition that the phases of B and R signals are different by 90 deg., while making the luminance signal Y a base band. In (n)+1 scanning sections, such signals as Y-B, Y-R, Y+B, Y+R... are similarly outputted. Consequently, when these signals are separated into Y, R and B, the signal applicable to the NSTC method can be obtained by the normal signal processing after said separation.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a single-chip color imaging device consisting of a color fill and a single solid-state image pickup device that forms an image through the color fill, and in particular, to This invention relates to a single-chip color imaging device designed to reduce false color signals.

<Prior Art> There are two types of signal charge accumulation methods for solid-state imaging devices: a field accumulation mode and a frame accumulation mode, corresponding to the interlacing of the standard television system. The former method reads out the signal charges of all pixels in about 1/60 seconds in the field CNTSC method, and the latter reads out the signal charges of half of the pixels every field. For this reason, although a high vertical resolution can be obtained with the frame accumulation method, there are problems such as the generation of afterimages associated with the readout method. Therefore, when capturing an image of a subject that moves quickly, the field accumulation mode is preferable.

On the other hand, there are two types of solid-state imaging devices: the CCD method and the XY address method.The large Y address method can simultaneously scan two horizontal columns and obtain two independent output signals, but the CCD method Only one output signal can be obtained. In terms of S/H, the CCD system is better than the XY address system.

Although this method is very advantageous, since only one output signal is obtained, the field storage mode cannot currently provide the same resolution as the XY addressing method.

The present invention has been made in view of the above, and provides a single-chip color imaging device having the following features at the same time.

a. Since it is a CCD system, the S/N ratio is good.

b. Field accumulation mode without afterimage.

C1 High resolution with less false color signals.

First, problems with conventional single-chip color imaging devices will be explained. As will become clear in the following explanation, this is due to the above a,
Although b is satisfied, c is insufficient.

FIG. 1 shows a conventional color fill arrangement disclosed in Japanese Unexamined Patent Publication No. 57-39684. That is, in this arrangement, in the n-th scanning period of the first field, W, G, W, G-.
The horizontal rows of . and the horizontal rows of Cy, Ye, C'y, Ye... are read out simultaneously, and W+Cy, G+Ye.

Output signals of W+Cy, G+Ye, . . . are obtained. Here, W=R+G+B, Cy=G1B, Ye=R, +G, and R, G, and B are red, green, and 71 color lights, respectively.

Now, if the luminance signal (Y) is approximated as Y = R + 2 G + B, W-1-Cy = Y + B, G + Ye = Y-B, so in the n-th scanning period, Y + B, Y-B, Y + B.

. . . is obtained. By performing low-pass filtering and removing the tone component, the brightness im signal is detected.

Still in the n+1 scanning period, Y−f<, Y+I<.

Output signals of Y-R, . . . are obtained, and the luminance signal is converted into . . . This method has the advantage of being able to use a CCD method with good S/H since only one output signal is required, and that it is a field accumulation mode with no afterimage. However, (1) a low-pass filter is required to remove the color signal of the modulation component, resulting in a decrease in horizontal resolution.

■ Since the R and B signals are not output every other horizontal period, it is necessary to interpolate this with a delay line of one horizontal period.
Produces false color signals in the vertical direction.

There is a drawback.

The second series shows another conventional train. This method is also a field storage mode, in which two horizontal columns are read out simultaneously. The luminance signal is obtained through a low-pass filter, while the chrominance signal is obtained as a B signal by detecting the addition of the current scanning signal and the IH delayed scanning signal, and an R signal by detecting the subtraction.

However, this method also requires low-pass filtering to remove the color signal of the modulation component, resulting in a decrease in horizontal resolution.

(2) A false color signal in an oblique direction occurs in the R signal obtained by detecting the addition of the current scanning signal and the IH delayed scanning signal.

There is a drawback.

<Object of the Invention> The present invention solves the above problems and provides a single-chip color imaging device having a new color fill arrangement and its signal processing method, which has the features described in a, b, and c above. It is.

<Example> A third example of a color fill array to which the present invention is applied
As shown in the figure. In other words, in this array, the basic unit is 4 pixels horizontally x 4 pixels vertically, a total of 16 pixels, and there is a fill that transmits gold light (hereinafter referred to as W fill) and a fill that transmits green light (hereinafter referred to as ζG fill). ), a filter that blocks red light (hereinafter referred to as a cy filter), and a filter that blocks blue light (hereinafter referred to as a Ye filter) are used. In the first and third horizontal rows, W and G filters are repeated with two pixels each,
In the first and third numbers, the ``A'' in the W and G positions are reversed.

Furthermore, in the second and fourth horizontal rows, cy and Ye filters are repeated for two pixels each, but the positions of cy and Ye are reversed in the second and fourth horizontal rows. Also, the first and second. In the second and third horizontal columns, the repetition pitch is shifted by one pixel, for example, ~■ in the first horizontal column, Cy in the second horizontal column directly below W,
A Ye fill is arranged, and a W and a G are arranged in the second horizontal row of Ye, and in the first horizontal row directly above Ye.

A solid-state imaging device equipped with this color fill simultaneously scans two horizontal rows as follows. (The two horizontal lines scanned at IIL 116 do not necessarily have to be output independently. Here, it is assumed that the signal calculated by the force 11 in the solid-state imaging device is output. In other words, the nth column of the first field In the th horizontal scanning period, W +Cy, W+Ye, G+Ye
, G-+-Cy, W-1-Cy.

and the summed signals of the two horizontal columns are output.

In addition, W = R + G + B C5 / = B + G Ye = G + R In addition, the luminance signal (Y) is the three primary colors that occupy the NTSC luminance: red (R), green (G), and blue (B). ) is R:G:B=
From 0.3: 0.59: 0.11, Y =
Approximating as R+ 2 G +B, w+Cy=y1'
I3. W+Ye=Y+R, G-1-Ye=Y
-B, G +Cy = Y-R, so the output signal uses the Elf degree signal Y as the baseband, and adds B and R (ffl- signals to the father tone with a 90° phase difference). It can be considered as a pillar.

On the other hand, in the (n+1)th horizontal scanning period, G+Ye.

G1Cy, W1Cy, W+Ye, G+Ye river and output signal-
The number is given as YIB, yf, r<, Y+B
, Y+R, Y-B.

Similarly, in the second field, the luminance signal Y is used as the baseband, and B and R (No. 8 is modulated with A11 being 90' and A11 is different) and output (l:i is 11-).

Therefore, if these signals are separated into Y, R, and B, then by performing normal signal processing, for example, N'Y
Since it is possible to obtain a loan that is compatible with the SC method, we will explain below how to separate it into Y, R, and B.

Figure 4 is an example of a nuisance signal processing circuit that performs this], I-1
'+ with delay circuit, addition circuit, subtraction circuit and synchronous detection circuit
'il) get pregnant. In other words, current inspector I 1, No. 1 and 1. ,
A luminance signal can be obtained from the sum of tJ (one pulse) delayed scanning signals.

Since this signal no longer contains R and B modulation components, there is no need for a low-pass filter to remove the modulation components as in the conventional case, and high horizontal resolution can be obtained.

Further, by phase-detecting the difference between the current scanning signal and the signal delayed by one horizontal period, a υB times signal R signal is obtained at t4). Since these signals do not need to be interpolated afterward and no diagonal processing is performed, the number of false color signals is extremely low.

FIG. 5 shows another embodiment of the separation circuit. Here, two 1-horizontal period delay lines are used, so that the current scan signal in FIG. 4 becomes the IH delay signal, and the 3. The H-delayed signal is the current scanning signal and the 2H-delayed signal.

Note that in these signal processing methods, the resolution in the vertical direction is slightly lower than in the conventional example. An example of a circuit for improving this problem is shown in FIG. Here, the luminance signal shown in Fig. 1fj5 is used as a 1i degree signal in the high frequency range, and the IH delayed signal is used as the low frequency luminance signal through low-pass filtering. This can prevent a decrease in vertical resolution. A similar approach can be applied to the circuit of FIG.

In FIG. 7, the Cy and Ye films in FIG. 3 are exchanged, and it is clear that the same effect as in FIG. 3 can be obtained even if the actual color film is used.

The 8th line 1 and the 91st line 1 show a color fill arrangement showing another embodiment in which the present invention is applied. Figure 81 is the third
In the figure, Fig. 9 shows a case in which the W film in Fig. 7 has been replaced with a filter (hereinafter referred to as Ma II letter) that blocks green light. If the degree signal (Y) is approximated as Y=R+-G+B, the output signal when two horizontal columns are read out at the same time will be the luminance signal Y as the baseband, and (B-
The (rising) signal and the (R-standing) signal are modulated in phase by 90°2. Therefore, the words Y, B, and R (words) can be obtained from these in FIG.

<Effects> By applying the present invention as described above, it is possible to realize a single-chip color imaging device with no afterimage, high resolution, and few false color signals.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams of the color ray/rec arrays used in conventional single-chip color imaging devices, and Figures 3, 7, 8, and 9 The figure is a diagram showing an example of a color fill arrangement used in a single-chip color imaging device to which the present invention is applied. 4, 5, and 6 are block diagrams showing examples of signal processing circuits using the color filter array according to the present invention. Agent Patent Attorney Aihiko Fuku (and 2 others) Off 7 (-
11-Do Sai 2 'h-IL/D 1 Figure 2 Figure 6 Figure 74-t Redo "O'24--To. Figure 7 Figure 8 Figure 9 Procedural Amendment 1982 1 Mon-70L1 Mr. Commissioner of the Negotiating Agency 2 Name of the invention Single plate color imaging device 3 Person making the amendment Relationship to the case Patent applicant 4 Agent address ■ 545 22-225 Nagaike-cho, Abeno-ku, Osaka-shi;
Spontaneous 6, more than the subject of correction "'ya" suru 7 (-bf 3 figure blow 7 figure 8 figure conflict 9 sekiichi!"%R9-

Claims (1)

[Claims] 1. In a single-chip color imaging device comprising a color filter and a solid-state imaging device that forms a subject image through the color filter, a first filter that transmits a first color light; The process of sequentially repeating sequentially in the horizontal direction that a filter is placed on the first and second pixels in the horizontal direction, and a second filter that transmits the second color light is placed on the third and fourth pixels in the horizontal direction. and a third filter that transmits the 30th color light are arranged in the first and fourth pixels in the horizontal direction, and a fourth filter that transmits the fourth color light is arranged in the horizontal direction. a second horizontal column in which the arrangement on the second and third pixels is sequentially repeated in the horizontal direction;
The second fill is placed on the first and second pixels in the water At direction, and the first fill is placed on the third and fourth pixels in the horizontal direction by sequentially turning the edges in the horizontal direction. A third horizontal column and a fourth filter are disposed on the first and fourth pixels in the horizontal direction, and a third filter is disposed on the second and third pixels in the horizontal direction. The fourth step was repeated sequentially.
A single-chip color imaging system characterized by comprising: a color filter formed by sequentially repeating horizontal rows in the vertical direction; and a signal processing circuit that separates primary color signals from pixel outputs passed through the color filter. Number ff'l', 2. In claim 1, the first filter is a filter that transmits all color light, the second filter is a filter that transmits green light, and the third filter is a filter that transmits green light. A single-chip color imaging device in which the filler is a filler that blocks red light, and the fourth filler is a filler that blocks blue light.3 In claim 1, the filter of ?IS1 is A filter that transmits all color light, a second filter that transmits green light, a third filter that blocks blue light, and a fourth filter that blocks red light. A single-chip color imaging device. 4. In claim 1, the first fill is a filter that blocks green light, and the second fill is a filter that transmits green light. , a single-panel color imaging device in which the third filler is a filler that blocks red light, and the fourth filler is a filler that blocks blue light.5. The first fill is a fill that blocks green light, the second fill is a fill that transmits green light, the third fill is a fill that blocks blue light, and the fourth fill is a fill that blocks blue light. A single-chip color imaging device with a filter that blocks red light. 6. In claim 1.2, 3.4, or 5, the signal processing circuit mixes pixel information of two adjacent horizontal columns. 7. A single-chip color imaging device, characterized in that the combination is changed between fields according to interlacing.7. A single-chip color imaging device characterized in that signal processing is performed using one or two delay lines for one horizontal period.