JPS60128785A - Solid-state color image pickup device - Google Patents

Abstract

PURPOSE:To miniaturize a device and to enhance picture quality by using a liquid crystal filter to function by applying an appropriate voltage as a filter provided on a two-dimensional photodiode. CONSTITUTION:A laminated liquid crystal filter 4 consisting of filters 41, 42 and 43 common to all element groups is provided on a photodetecting element group 2. The laminated filter 4 functions as a colorless filter to transmit all spectrum areas by controlliig of a filter control circuit 55. At this time, an output of each photodetecting element group is read out through coordinate selection circuits of X and Y axes 52 and 53, and transmitted to a color picture signal processing circuit 56. If this scan is completed, the liquid crystal filter 41 is set on in order to transmit only a red color, and a red color picture can be obtained. In this case, a liquid crystal layer has appropriate thickness, and functions by impressing a proper voltage. Picture with green and blue light beams can be obtained by the liquid crystal filters 42 and 43 in the same manner. A choloesteric-based liquid crystal can be used as a laminated filter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a solid-state color imaging device, and particularly to a filter thereof.

[Prior Art] Various types of solid color 11i11D devices have conventionally existed. For example, in JP-A No. 55-675, a solid-state color 1ll image device has a plurality of light-receiving elements arranged two-dimensionally in the vertical and horizontal directions, and is arranged in a mosaic pattern corresponding to each of these light-receiving elements. A colored filter element is provided. In this configuration, the color image is 1q
For example, in order to obtain the three primary colors of light, R (red), G (green), and B (blue), at least three groups of light receiving elements are required as color signals of one pixel, and in reality, brightness In order to detect this, a light-receiving element corresponding to white, which transmits gold, is also used. An example of such a solid-state color image mounting port is shown in Fig. 1. Fig. 1(a) shows the arrangement of filters on its top surface, and Fig. 1(b) shows its cross section. Fi! It is a schematic diagram of a one-story rental building.

In FIG. 1(b), the light receiving elements are arranged on the main surface of the silicon substrate 1. - is formed, and each light receiving element 2
1, 22, 23, 24, etc., a color filter array layer β- consisting of white (W), cyan (Cy), green (G), yellow (Ye) is formed corresponding to the position of the light receiving element. 4n are configured so that I color signals are extracted from one light receiving element. A color image is obtained by providing a large number of these color regions in a matrix on the surface of a semiconductor chip as shown in FIG. 1(a).

In the solid-state color imaging device configured in this way,
The number of pixels forming a color image is one fourth of the number of light receiving elements arranged in a plane. This is a black and white image with the same ffi! This means that four times as many F-1 diodes are required to color at m degrees.

There is also a method of overlapping color filters on multiple light-receiving elements that are arranged in a plane and synchronizing them to obtain the same color signal as described above and synthesizing it using an electric circuit, but this method requires a larger device. In addition, special measures are required to synchronize several systems and the electrical system, resulting in a complex 4pH system and electrical circuit, which is prone to failure and has drawbacks such as being expensive.

[Summary of the Invention] The present invention eliminates the drawbacks of the conventional solid color MTA mounting system as described above, reduces the size of the solid color MTA mounting system, and
It also aims to improve image quality.

Mizumoto One] is characterized by two-dimensional arrangement on a semiconductor substrate? i f& F first diodes and said F E diodes;
A solid color repellent (with a filter for each diode)
! d3 in the first row, and a liquid crystal filter that functions by applying an appropriate voltage is used as the filter.

[Embodiment of the Invention] An embodiment of the present invention will be described with reference to FIGS. 2 and 3. In FIG. 2, a semiconductor substrate 1 made of silicon or the like is shown.
As in FIG. 1, there is a group of light receiving elements 2? on the main surface of the ? - is formed. Those light receiving elements? - A laminated filter tip consisting of three layers of filters 41, 42, and 43 common to all the element groups is provided above.

From such a solid color SWA board, a color image signal can be obtained by a 4n configuration as shown in FIG. In FIG. 3, the laminated filter L is first controlled by the filter control circuit 55 to pass light in the entire spectral range, and all the filters 41, 42, 43 in each layer are in the off state, i.e., the filters are colorless filters. as 1lt
fil. At this time, the image passes through the lens (not shown) and its filter layer to the light receiving element group. - Rust is formed on top. The output from each photodetector group depends on its operation,
The image is scanned and read through an X@coordinate selection circuit 52 and a Y@coordinate selection circuit 53 controlled by an XY control circuit 51, and sent to a color image signal processing circuit 56. When the entire skinning is completed, the synchronization control circuit 54 is notified. The filter control circuit 55 receives the scan completion signal from the synchronization control circuit 54, and then controls the first liquid crystal filter layer (for example, 41) to transmit only the light in the first spectral region (for example, R; red). is turned on to function as a red filter to obtain a red image. The first filter layer functions by applying an appropriate voltage to the thick layer, and by changing the voltage to 0 or vice versa, the filter When the conversion to the red filter is completed, a signal is sent to the X-V 1lil Fll four-way via the synchronization control circuit 54, and scanning is started in the same manner as described above. The output signal corresponding to the red image is sent to the color image color signal processing circuit 5.
Sent to 6. When the scanning for the red image is completed in this way, a signal is sent to the filter control circuit 55 in the same way as described above, and an image is then obtained using light in the second spectrum/lumin range (for example, G; green). For this purpose, the first filter layer is turned back to colorless and the second filter layer (eg 42) is turned on to function as a green filter. After this green image is scanned, a third filter layer (eg, 43) is activated to obtain an image in a third spectral region (eg, B: blue).

The images of light in each spectral region thus obtained are electrically combined in a color image signal processing circuit 56 to obtain a color image. Further, the above-mentioned scan cycle for each spec [/distance] area is repeated in sequence, and a color image (M) can be obtained continuously.

In the above example, 91N1 + 42 + and the third
Each filter in the spectral region of! By using cholesteric liquid crystal as the liquid crystal for the filter, forming it in one layer with an appropriate thickness, and applying a voltage suitable for each spectral region. , the above-mentioned No. 1. It is also possible to construct a filter that combines the functions of the second and third filters and can also communicate light in the entire spectral range by applying an off or reverse voltage.

[Effects of the Invention] According to the invention, if a liquid crystal filter is used, the filter patterning ability can be electrically controlled, so the number of light-receiving element groups can be reduced to one-fourth of the conventional one. As a result, the solid-state color imaging device can be made smaller and its image quality can be significantly improved.

[Brief explanation of drawings]

FIG. 1 is a partial schematic diagram showing an example of a conventional solid-state color imager. FIG. 2 is a partial schematic diagram showing an example of a solid-state imaging device according to the present invention. FIG. 3 is a schematic block diagram showing an example of the configuration related to the operation of the solid-state image transfer device according to the present invention. In the figure, 1 is a semi-dedicated substrate, 1 is a group of light receiving elements, β-
is a color filter layer, and the king is a laminated liquid crystal filter, 41.4
2.43 is each liquid crystal shield that constitutes the laminated liquid crystal filter, 5
1 is an X-YIIJgI1 circuit, 52 is an X-axis coordinate selection circuit, 53 is a Y-axis coordinate selection circuit, 54 is a synchronous control circuit, 55
Reference numeral 56 indicates a filter control circuit, and 56 indicates a color image signal processing circuit. In each figure, the same reference numerals indicate the same parts. Agent Masuo Iwa

Claims (4)

[Claims] (1) A solid color R image device comprising a semi-dedicated body, a plurality of photodiodes arranged two-dimensionally on the surface layer of the semiconductor elongated body, and a filter provided on the photodiode. In the solid-state color imaging device, the filter is a liquid crystal filter that is activated by applying an appropriate voltage. (2) The liquid crystal filter is a laminated liquid crystal filter formed of multiple layers, and the first layer in the IO layer has an appropriate thickness and can emit visible light by applying an appropriate voltage. transmitting either light in the entire spectral region or light in the first spectral region; a second layer within said minority layer has a suitable thickness; Peri 1 hell territory!
a third gate in said plurality of layers has a suitable thickness and transmits light in said entire spectral range by applying a suitable voltage; or a third spectral region; Second. and a third spectral region, the light in the entire spectral region, the first spectral region, the second spectral region, and the third spectral region can be controlled at any time by applying an appropriate voltage to each of the third spectral regions. The solid-state color imaging device according to claim 1, wherein the solid-state color imaging device is capable of selectively transmitting light in any one of the spectral regions. (3) Above 1. Second. and 8r! 3. The solid-state color facial photographing device according to claim 2, wherein the entire spectral region of No. 3 covers the entire spectral region of visible light. (4) The liquid crystal filter is formed of a single layer of cholesteric liquid crystal having an appropriate thickness, and by appropriately selecting the voltage applied thereto, it is possible to control the entire visible light spectral range and the first spectrum. area, said second
spectral range. 2. The solid-state color imaging device according to claim 1, wherein the solid-state color imaging device is capable of selectively transmitting light in any one of the light in the third spectral region and the light in the third spectral region.