JPS58106947A - Optical sensor - Google Patents

Abstract

PURPOSE:To make a high-luminance spot illumination possible, by incorporating materials, which become a transparent material by oxidation, one, at least, light guiding system for illumination, which is formed into a transparent material by oxidation, in an optical sensor including the light guiding system for illumination and a photodetector. CONSTITUTION:A part of a silicon substrate 8 which becomes a transparent material by oxidation is converted to a silicon dioxide by an anodic oxidation method to form an incident light guiding system 10 which guides an input light 11 to an illumination point 13 on an original surface 9. The incident light 11 is reflected at the illumination point 13, and a reflected light 12 is detected directly or through reflected light guiding systems 10a on both sides of the incident light guiding system by a photodetector 14. Consequently, a spot on the original surface is illuminated with high illuminance, and structures of the illumination system and reflected light guiding systems are made simple and inexpensive.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to an optical sensor, and more particularly to an optical sensor in which a portion made transparent by oxidation serves as at least a light guide path for light irradiation.

(2) Background of the invention With the rapid development of electronics in recent years, information
%lIl technology has made remarkable progress, and optical sensors are playing an important role as elements for these information input devices.

Against this background, optical sensors are being developed not only as simple photoelectric conversion elements but also as integrated sensors with many functions.

(3) Prior Art and Problems FIG. 1 shows a schematic sectional view for explaining a conventional optical sensor.

In the figure, [ is a substrate made of, for example, plastic, 2
3 is a light source, 3 is a document surface, 4 is reflected light generated by the light emitted from the light source 2 hitting an illumination point 3' on the document surface, 5 is an optical fiber, and 6 is a light receiving element (sensor).

As shown in FIG. 1, a light source 2 is attached to a V-groove 7 provided on the substrate 1, and a reflected light beam 4 that illuminates an illumination point 3' on the document surface 3 is received by a diffusing fiber 5. The light is guided to the element 6. This conventional close-contact optical sensor uses a light source located close to the document surface to illuminate the document surface, a round lens system (not shown) that focuses the light emitted from the light source, and then directs the light to a light receiving element. Special equipment to lead (optical fiber go)
was necessary, and the structure had to be expensive.

Furthermore, the light emitted from the light source is not used effectively, and the light emitting part has a lens effect, which converges on the illumination point on the document surface, but the light source is spatially restricted. There are drawbacks.

(4) Purpose of the Invention In view of the above-mentioned drawbacks of the conventional art, it is an object of the present invention to provide a band-layer optical sensor capable of providing high-intensity spot illumination on the surface of a document.

Furthermore, it is an object of the present invention to provide a close-contact light sensor that has a simple illumination system and a reflected light guide system and is inexpensive.

((Transition) Structure and object of the invention According to the present invention, in an optical sensor including a light guide system for illumination and a light-receiving element, a material Kmm which becomes a transparent body against acid oxidation is formed into a transparent body against acid oxidation. This is achieved by a light sensor, characterized in that it combines at least one of the above-mentioned light guide systems for illumination.

(6) W140 example Embodiments of the present invention will be described in detail below with reference to Figure wK.

FIG. 2 is a schematic sectional view showing the structure of an optical sensor based on unexploded 1jlK.

In the figure, 8 is, for example, a silicon substrate, 9 is a document surface, and 1
0 is a transparent illumination light guide system formed by oxidizing the silicon substrate, 1 is a transparent reflective light guide system, 11 is incident light, 12 is reflected light, 13 is an illumination point on the document surface 9, Reference numeral 14 indicates a light receiving element.

For example, a part of a silicon substrate 8, which becomes transparent due to oxidation, is made into silicon dioxide (Si02) K by anodizing to form an incident light guide system 10 that guides incident light 11 to an illumination point 13 on the document surface 9. The electrolyte for the anodic oxidation is water 1000 (C
C) to which 1.9 citric acid was added was used. The incident light guide system 110@1 is set to about 10,100 (J1) and the incident light is converged to illuminate the illumination point 213.The incident light 11 is reflected at the illumination point 13, and the reflected light 12 is divided into, for example, the above-mentioned incident light. Similar to the incident light guide system 11 on both sides of the light guide system, the reflected light guide system 101 made of silicon dioxide (81) formed by anodizing is detected by the light receiving element 14.

The width of the reflected light guide system 10a! Snow is about 10100 (j
The length of each light guiding system was approximately l [■]. Further, the distance ts between the light guide system and the document surface is preferably about 300 (μm).

In addition to silicon according to the present invention, materials that become transparent (by anodizing) include aluminum (*2), tungsten (incorporated), tantalum ('!'a), etc.; Available.

In Figure 3, nine incident light beams 11' simply enter the incident light guide system 10'.
shows a structure in which the light is reflected by the illumination point 13' on the document surface 9' and is immediately detected by the light receiving element 14'. That is, the light receiving element 14' is disposed, for example, on the opposite side of the silicon base I[8' to the side on which the incident light beam 11' is irradiated.

In the present invention, a two-dimensional or one-dimensional (line) sensor is constructed by increasing the number of incident light guide systems and reflected light guide systems using photoringraph technology.

(η Effect of light emission W14 As explained above, the optical sensor of the present invention can use a general high-intensity light source, so it is possible to provide high-intensity point illumination on the document surface. The structures of the reflected light guide system and the reflected light guide system can be made simple and inexpensive.

[Brief explanation of the drawing]

FIG. 1 shows a schematic sectional view for explaining a conventional optical sensor, and FIGS. 2 and 3 are schematic sectional views showing an embodiment according to the present invention. 1... Board, 2... Light source, 3... Document surface, 3'.
...Illumination point, 4...Reflected light, 5...Optical fiber, 6
...Photodetector, 7...V groove, 7...Silicon substrate,
9, 9'... Original surface, 10-, 10'... Incident light guide system, 11, 11'... Incident light, 12, 12'
...Reflected light, 13.13'...Illumination point, 14.1-
4'-'... Light receiving element.

Claims (1)

[Scope of Claims] An optical sensor including a light guide system for illumination and a light receiving element, wherein at least one light guide system for illumination is formed into a transparent body by acid oxidation using a material Kmm that becomes a transparent body by oxidation. An optical sensor comprising: