JPH0524195Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical sensor that uses an amorphous semiconductor such as amorphous silicon and has a light blocking property.

[Prior art]

Optical sensors using amorphous semiconductors that are sensitive in the visible light region as their light receiving elements have been developed and put into practical use. An optical sensor using an amorphous semiconductor can be formed on a transparent insulating substrate such as glass, and on this substrate is a transparent conductive film that becomes an electrode on the incident light side, and a film-like film made of amorphous silicon or the like. The amorphous semiconductor layer and the back electrode are sequentially laminated by photolithography or the like, and a plurality of fine light-receiving elements are arranged in a matrix and patterned. Furthermore, the surface of these light receiving elements is coated with a transparent resin to protect the light receiving elements, and by distributing fine light receiving elements in a matrix over the entire optical sensor, it has a so-called translucent property. We have realized a translucent optical sensor and are expanding its application to automatic focus detection elements for cameras. Light incident on the optical sensor enters the light receiving element from the light-transmitting insulating substrate and is photoelectrically converted, while light incident on areas other than the light receiving element is transmitted.

Further, as an optical sensor that can block incident light to the optical sensor and make the transmissive optical sensor opaque at any time, there is an optical sensor using liquid crystal, the structure of which is shown in FIG. As described above, this optical sensor 20 includes a light-transmitting insulating substrate 1 on which a light-receiving element 5 is laminated.
A transparent electrode 3 is formed on the opposite surface of the substrate 1 by etching such as photolithography, and another transparent electrode 4 is formed on one surface of the substrate 1 at an appropriate distance apart from the substrate 1 by etching in the same manner as described above. A shutter mechanism is provided by disposing a transparent insulating substrate 2 and sealing a liquid crystal 7 between these transparent electrodes 3 and 4. That is, the light passes through the substrate 2, the liquid crystal 7, and the substrate 1.
The light enters the light receiving element 5 through the transparent electrode 3,
When the voltage at 4 exceeds a predetermined value, the liquid crystal 7 is driven to block the incident light from the transparent electrode 4 side, making the optical sensor 20 opaque. Note that the transparent insulating substrate 1,
2, polarizing plates 8 and 9 are provided on opposite surfaces of the surfaces on which the transparent electrodes 3 and 4 are provided, respectively, and linearly polarized light is extracted from the incident light and made to enter the light receiving element 5. Further, the surface of the light receiving element 5 is coated with resin 11 to protect it from external impact.

[Problem that the invention attempts to solve]

By the way, as shown in FIG. 6, a conventional optical sensor equipped with a shutter mechanism uses double-sided etching to form a light-receiving element 5 on one side of a light-transmitting insulating substrate 1 and a transparent electrode 3 for driving a liquid crystal on the other side. It is necessary,
The problem was that it required a complicated manufacturing process.

The present invention has been made to solve these problems, and aims to provide an optical sensor that has a shutter mechanism and has a simple manufacturing process.

[Means for solving problems]

The present invention provides an optical sensor in which a light-receiving element in which a back conductive film, an amorphous semiconductor layer, and a transparent conductive film are laminated is disposed on one surface of an insulating substrate, and an electrode provided on one surface of the insulating substrate; An insulator disposed on the surface of the electrode, a transparent electrode disposed at an appropriate distance from the electrode, and an insulator sealed between the electrode and the transparent electrode, and driven by the electrode and the transparent electrode. and a light-shielding material, and the light-receiving element is arranged on the insulating substrate with an insulator interposed therebetween.

[Effect]

In the optical sensor of the present invention, an electrode is provided on one side of an insulating substrate, and a light-receiving element consisting of a back conductive film, an amorphous semiconductor layer, and a transparent conductive film is laminated on the surface of this electrode via an insulator. A transparent electrode is provided at an appropriate distance from the electrode on the side where the light receiving element is formed, and a light shielding material is sealed between the electrode and the transparent electrode.
The light-shielding material is driven based on the level of voltage applied to the electrode and the transparent electrode to block incident light from the transparent electrode side.

〔Example〕

Hereinafter, the present invention will be described in detail based on drawings showing embodiments thereof. FIG. 1 is a partial sectional view schematically showing the structure of an optical sensor in which liquid crystal is used as a substance for controlling incident light according to the present invention. In the figure, reference numerals 1 and 2 are translucent insulating substrates made of glass or the like that are spaced apart by a required length, and one side 1a and 2a of each of these are provided.
A liquid crystal drive device (described later) is applied to a transparent conductive film on which a transparent conductive oxide (TCO) such as tin oxide (SnO ₂ ) or indium tin oxide (ITO) is deposited by vapor deposition or thermal CVD. Transparent electrodes 3, 4 for
is formed by patterning using photolithography or the like. On the surface of one transparent electrode 3, a light-receiving element 5 is formed by laminating a light-receiving element electrode 53, a film-like photoelectric element layer 52, and a light-receiving element electrode 51 in this order from the substrate side. A required number of wafers are distributed one-dimensionally or two-dimensionally through an insulating film 6 formed slightly wider than the surface of , using a photolithography method or the like. Between each light receiving element, electrodes 51 or 53 for light receiving elements are wired so as to be electrically connected to each other, and the wiring portion is insulated from the transparent electrode 3 by an insulating film formed a little wider than this. . Note that the light-receiving element electrodes 51 and 53 are made of a transparent conductive film similar to the transparent electrodes 3 and 4, the film-like photoelectric element layer 52 is made of an amorphous silicon-based semiconductor, and the insulating film 6 is made of Si having a light-transmitting property. ₃ N ₄ or SiO ₂ is used.

Further, a liquid crystal 7 is sealed between the two transparent insulating substrates 1 and 2, and the liquid crystal 7 is driven based on the level of voltage applied to the transparent electrodes 3 and 4. Further, the other surface 1 of each of the transparent insulating substrates 1 and 2
Polarizing plates 8 and 9 are provided on b and 2b, and linearly polarized light is extracted from the incident light and transmitted.

That is, one of the light-transmitting insulating substrates 1 and 2 can be said to be an element forming substrate on the surface of which the light receiving element 5 is formed and held, and the other is an element cover substrate that protects the light receiving element 5 from external impact. Light can enter from both sides of the transparent insulating substrates 1 and 2, and the light that has passed through the transparent insulating substrate 1, which is the element forming substrate, passes through the transparent electrode 3, the insulating film 6, and the electrode 53 for the light-receiving element. Through,
The light that enters the film-like photoelectric element 52, is photoelectrically converted, and passes through the light-transmitting insulating substrate 2, which is the element cover substrate, passes through the transparent electrode 4, the liquid crystal 7, and the light-receiving element electrode 51, and then becomes the film-like photoelectric element. The light enters the element 52 and is photoelectrically converted. Furthermore, light other than the light incident on the light receiving element 5 is transmitted in the opposite direction. In addition, transparent electrodes 3 and 4
When a voltage higher than a predetermined value is applied to the liquid crystal 7 and the liquid crystal 7 is driven, the incident light from the side of the transparent insulating substrate 2 serving as the element cover substrate is blocked and does not enter the light receiving element 5, thereby realizing a shutter mechanism. do.

FIG. 2 is a schematic plan view of the optical sensor of the present invention in which a plurality of light-receiving elements are arranged in a matrix, as seen through the liquid crystal from the translucent insulating substrate 2 side, which is the element cover substrate. The figure is a partially enlarged view. Both light receiving element electrodes 51 and 53 of each light receiving element 5
form conductive patterns that are electrically continuous in the horizontal or vertical direction, respectively, and are insulated from the transparent electrode 3 by an insulating film 6 provided wider than the conductive patterns. Furthermore, when the liquid crystal 7 is not driven, light can enter from both sides of the optical sensor, but when the liquid crystal 7 is driven as shown in FIG. It is incident only from the direction. In this embodiment, a liquid crystal is sealed over the entire surface of the optical sensor to control the incident light to the front light receiving element, but as shown in FIG. It is also possible to provide a structure in which a transparent electrode is provided and only a portion of the liquid crystal 7 is sealed to control incident light.

Further, in this embodiment, the case where liquid crystal is used as the material for blocking incident light has been described in detail, but it is also possible to use a dielectric material such as PLZT instead of liquid crystal to block incident light.

A light-transmitting optical sensor as described above can be used, for example, as a photometric sensor for a camera that automatically controls exposure. FIG. 7 is a schematic diagram showing an example of its use, in which the optical sensor is placed inside the camera near the viewfinder 12, and the element cover substrate side, where incident light is blocked by driving the liquid crystal, is placed in the viewfinder 12. Provided facing each other. The light transmitted through the lens 13 is reflected to the upper part of the camera by the reflecting mirror 14, and further reflected by the upper part of the camera, and the reflected light is transmitted to the translucent optical sensor 10.
, and its image becomes visible from the viewfinder 12. Next, in order to determine the appropriate exposure for photographing, the liquid crystal of the optical sensor is driven to the viewfinder 12.
Unnecessary incident light from the subject is blocked, and only the amount of incident light from the subject side is measured. The light incident on the optical sensor 10 is photoelectrically converted according to the amount of light, then amplified by the amplifier 15, and appropriate exposure is determined based on the value. Therefore, in cameras with automatic exposure control in which a photometric element is placed near the viewfinder due to the mechanism of the camera, by blocking unnecessary incident light from the viewfinder, only the required amount of incident light can be measured, making it possible to accurately measure the amount of incident light. Exposure can be determined.

Further, in this embodiment, the light receiving element 5 is formed on the surface of the transparent insulating substrate 1, but the same effect can be obtained even in an optical sensor in which the light receiving element is formed on the surface of a non-transparent insulating substrate. .

〔effect〕

The optical sensor with a shutter mechanism of the present invention has a light-receiving element formed on the surface of a transparent electrode for driving the shutter mechanism, eliminating the need for double-sided etching of a transparent substrate, and further providing the other electrode for driving the shutter mechanism. By providing a substrate made of glass or the like with a function to protect the light-receiving element and eliminating the need for a protective coat of resin, an excellent effect is achieved in which the manufacturing process is simplified.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of the optical sensor according to the present invention.
Fig. 2 is a schematic plan view, Fig. 3 is a partially enlarged view thereof,
Fig. 4 is an embodiment of a shutter mechanism, Fig. 5 is an embodiment of another shutter mechanism, Fig. 6 is a partial cross-sectional view of a conventional optical sensor, and Fig. 7 is an optical sensor according to the present invention used in a camera. FIG. DESCRIPTION OF SYMBOLS 1, 2... Transparent insulating substrate, 3, 4... Transparent electrode, 5... Light receiving element, 6... Insulating film, 7... Liquid crystal, 51... Electrode for light receiving element, 52... Film photoelectric Element layer, 53...electrode for light-receiving element.

Claims (1)

[Claims for Utility Model Registration] 1. An optical sensor in which a light-receiving element in which a back conductive film, an amorphous semiconductor layer, and a transparent conductive film are laminated is disposed on one surface of an insulating substrate, including: an insulator disposed on the surface of the electrode; a transparent electrode disposed at an appropriate distance from the electrode; and a transparent electrode sealed between the electrode and the transparent electrode; A light-shielding substance driven by a light-shielding substance, wherein the light-receiving element is disposed on the insulating substrate with an insulator interposed therebetween. 2. The optical sensor according to claim 1, which uses liquid crystal as the light-shielding material. 3. The optical sensor according to claim 1, which uses a dielectric material as the light shielding material.