JPS6010204A - Solid-state color image pickup device - Google Patents

Abstract

PURPOSE:To obtain high output and to improve resolution and color reproducibility by forming at least one color filter to have the same spectral characteristic as that of the complementary color of three primary colors and providing a non-transmission region near the intermediate wavelength of the other two primary color wavelengths. CONSTITUTION:A filter 2 in front of a photoelectric converting part is disposed with a set of color filters 20 in a grating shape and is provided with four filters Fs 21-24 for one picture element. Fs 21, 22 are white W and green G and F23 is quasi-cyan C', has the substantially the same spectral characteristic as that of the cyan C and has a non-transmission region near the intermediate wavelength of the blue B and the green G. F24 is quasi-yellow Y', has the same spectral characteristic as that of the yellow Y and has a non-transmission region near the intermediate wavelength of the green G and the red R. The signal of F22 for the green G is used as it is for the signal G among the three primary colors. The signal for the blue B is obtd. by subtracting the output of G from the output of C' and coincides roughly with the true region B. The signal for the red R is also obtd. simply by subtracting the output of G from the output of Y'.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a color solid-state imaging device, and more particularly, to a color solid-state imaging device having color filters of complementary colors of primary colors KN in rows.

[Technical background of the invention and its problems]

Color solid-state photography @! The device M obtains an output signal according to the intensity of the three primary color components contained in the incident light by providing a color filter in front of the photoelectric conversion section. Color filters are composed of sets of multiple types of color filters, and as shown in Figure 1, three color filters through which the three primary colors of red (R), green (()), and blue (B) are transmitted are used. One set of primary colors and yellow (Y), which is a complementary color to these three primary colors, as shown in Figure 2.
), cyan (0), and magenta (M) are transmitted through a set of eight color filters. As shown in Figure 2, a yellow (Y) color filter transmits both red (R) and black (G) components, and a cyan (C) color filter transmits blue (B) components.
) and green (G), and a magenta (M) color filter transmits both blue (B) and red (R) components, so complementary color filters are primary color filters. Compared to other color filters, the absolute amount of transmitted light is larger, and the advantage is that a larger output signal can be obtained. The resolution is determined by the amount of green (G) light, so the greater the amount of transmitted green (G) light, the better the resolution, but complementary color filters are advantageous in this respect as well.

However, with a solid-state imaging device that uses complementary color filters,
When obtaining output signals corresponding to the three primary colors, there is a problem in that the signals corresponding to the three primary colors cannot be obtained correctly. This is because in order to obtain signals corresponding to the three primary colors from output signals corresponding to complementary colors, calculations are performed from output signals corresponding to the complementary colors.

This point will be discussed in detail. For example, cyan (0)
, yellow (Y), and green (G) color filters are used as a set. Green (G) is a primary color, but if cyan (C) and yellow (Y) are overlapped, green (G) will be transmitted, so this is a frequently used combination. Blue (B), which is a primary color other than green (G), is derived from green (G) from the cyan (C) output signal.
This is because it is sufficient to subtract the output signal of red (l) from the output signal of green (G) from the output signal of yellow (Y). However, as shown in Fig. 3, the output signal of cyan (0) The output signal obtained by mentally calculating the green (G) output signal from the output signal is
This corresponds to the area of the shaded area in FIG. 3, and does not necessarily correspond to the blue (B) area shown in FIG. 2. Similarly for red (R) K, the red (R) shown in Figure 1
The area does not match. Therefore, when the blue (B) and red (R) signals obtained in this manner are used, the colors differ from the actual colors, resulting in a problem of poor color reproducibility.

[Purpose of the invention]

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a solid-state Igi device that can produce a large output signal, a signal with good wt image resolution, and good color reproducibility. shall be.

[Summary of the invention]

The present invention 0 to achieve this purpose? At least 9 of the color filters of color solid-state imaging devices based on C? The spectral characteristics of the two color filters are almost the same as the spectral characteristics of the complementary color to one of the three primary colors, and are not close to the intermediate wavelength of the other two of the three primary colors. It is characterized by having a transmission region.

[Embodiments of the invention]

FIG. 4 shows a color solid-state imaging device according to an embodiment of the present invention.
Shown in 5th +-゛a. A color filter 2 is provided in front of a light weight converting section 1 that accumulates signal charges according to the intensity of light. The color filter 2 is constructed by arranging a set of color filters 20 in a matrix. The color filters 20 correspond to 11 pixels, and are composed of four filters 2], 22, 23, and 24, as shown in FIG. 6'. Filter 2] 1d It is a white (W) filter and transmits all three primary colors. Filter 22Fi is a green (G) filter. The feature of this example b11i lies in the spectral characteristics of the filters 23 and 24. It is a quasi-cyan (C) filter with 23 filters, and its spectral characteristics are approximately -1 the same as those of cyan (C), as shown in Figure 7, but it has a spectral characteristic of blue (B) and green (G). The filter 241d is a quasi-yellow (Yl) filter, and its spectral characteristics are the same as those of yellow (Y), as shown in FIG. However, it has a non-transmissive region 11 near the wavelength between green (G) and red (R).Such a spectral layer filter can be obtained by providing multiple layers of thin films on Galanu. It is possible. i!, t i, I, two filters may be used by superimposing them. In other words, the spectral characteristics of quasi-cyan (C") are the same as those of the cyan (C) filter and spectral characteristics 1 in Fig. 71.
It can be obtained by superimposing the filters of 2 and 2, and the quasi-yellow (
The spectral characteristics of Y') can be obtained by superimposing the yellow (Y) filter and the filter of spectral characteristics 13 in FIG.

The incident light passes through the color filter 2, and signal charges corresponding to the amount of the transmitted light are generated and accumulated in each part of the photoelectric converter 1. This accumulated signal charge is read out and output signal ′
f: Get. Of the three primary colors, the green (G) signal is
The output signal from the light transmitted through the filter 22 may be used as it is. The green (B) signal is obtained by subtracting the green (G) output from the quasi-cyan (C) output signals. l
Due to the presence of O, it almost matches the true blue (B) region. As for the red (Ft) signal, the green (G) output signal is also reduced from the semi-yellow (Y') output signal.

Blue (B) was thus obtained in this example.

The red (R) signal is almost the same as the true signal. Therefore, if you use these No. 15, you can get something close to the actual color. A
can be done. Furthermore, the advantages of complementary color filters, such as a large output signal and good resolution, still remain.

In this actual trim example, white (W), green (G), semi-cyan (
C1) and quasi-yellow (Y') filters are used as a set, but the present invention can be applied to any combination that includes at least one complementary color filter.

〔Effect of the invention〕

As described above, according to the present invention, a large output signal can be obtained,
A signal with good color consistency can be obtained without sacrificing the advantage of the complementary color filter, which has good resolution.

[Brief explanation of drawings]

Figure 1 is a graph of the -Yt and % characteristics of primary color filters, Figure 2 is a graph of the spectral characteristics of complementary color filters, and Figure 3 is a graph of blue ('B) obtained with a conventional solid-state imaging device. ), FIG. 4 and wJ5fm are a top view and a top view of the main parts of a color solid-state imaging device according to an embodiment of the present invention, respectively, and FIG. 6 is a set of colors used in the same device. The plan view of the filter, Figures 7 and 8 are graphs of the spectral characteristics of each filter used in the same device, and Figure 9 is a graph of the spectral characteristics of blue (B), which is 4Q produced by the same device. Ruru. 1... Photoelectric conversion unit, 2... Color filter, '20...
- Set of color filters, 21... White (W) filter,
22... Green (G) filter, 23... Semi-cyan (
A C filter, of course...a quasi-yellow (Y') filter. Applicant's agent Kiyotaka Inomata 4 Wavelength (7La) - Child 3 (limb length m) Figure 5 Child 6

Claims (1)

[Scope of Claims] A plurality of types of color filters that selectively transmit incident light according to its spectral characteristics, and a signal charge that is generated and accumulated according to the intensity of the transmitted light of the plurality of color filters. Equipped with a photoelectric conversion section and an output section that reads out and outputs the signal charge accumulated in the photoelectric conversion section, the signal charge contained in the incident light is
- In a color solid-state imaging device that obtains an output signal according to the strength of three primary color components, the spectral characteristics of at least one color filter among the plurality of types of color filters are determined with respect to one of the three primary colors. A color solid-state imaging device characterized by having a non-transmissive region having substantially the same spectral characteristics as complementary colors and near a wavelength intermediate between the wavelengths of the other two of the three primary colors.