JPH0524028Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a color sensor that discriminates the color of detected light from an object to be detected.

[Prior art] Conventionally, in this type of color sensor, the fifth
As shown in the figure, three light receiving elements 14, 15 and 16 are arranged on the image forming surface of the optical lens 13 to detect the three primary colors.
These light receiving elements 14, 15 and 1 are arranged side by side.
The detection light from the object to be detected 17 is sent to the optical lens 13 to 6.
A device is provided that allows the light to enter through the . However, in such a configuration, when the detected object 17 becomes minute, the optical lens 13 from the detected object 17
A situation may occur in which the detected light does not enter the entire three light receiving elements 14, 15 and 16, but only enters, for example, one of them, and as a result, the color of the detected light is misjudged. It was hot.

In order to solve the above-mentioned drawbacks, conventionally, as shown in FIG.
9 and three light receiving elements 14, 15 and 16 for detecting the three primary colors are combined, and the detection light from the detected object 17 is transmitted through the optical lens 13 to the first semi-transparent mirror 18.
By making the detected light incident on the first
The remaining detection light is reflected by the semi-transparent mirror 18 and incident on the first light receiving element 14.
By making the transmitted light of the semi-transparent mirror 18 enter the second semi-transparent mirror 19, a part of the light is reflected by the second semi-transparent mirror 19, and the light is transmitted to the second light receiving element 1.
5, and the remaining light transmitted through the second semi-transparent mirror 19, which is the remaining light transmitted through the first semi-transparent mirror 18, is incident on the third light-receiving element 16. However, such a configuration requires an optical structure that combines two semi-transparent mirrors 18, 19 and three light receiving elements 14, 15, and 16, resulting in a problem of increased size.

[Purpose of invention]

The present invention was developed in view of the above points, and its purpose is to provide a color sensor that can reliably discriminate the color of an object to be detected even if it is minute, and that can also be miniaturized. It is on offer.

[Summary of the idea]

The present invention allows detection light from an object to be detected to be incident on one end surface of a unidirectional refractive index slab lens in a small area state, and at the same time detects a plurality of different colors on the other end surface of the slab lens. It is characterized by the addition of elements.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In FIG. 1, reference numeral 1 denotes an optical lens that condenses detection light from an object 2 to form an image 3, and one of the optical fibers 4 is connected to the intersection of the optical axis A of this optical lens 1 and the image 3. An end is provided. Reference numeral 5 denotes a rectangular unidirectional refractive index gradient slab lens, and the optical fiber 4 is disposed at the center of one end surface 5a in the longitudinal direction.
At the center of the other end surface 5b, three light-receiving elements for detecting a plurality of colors, for example, three primary colors, ie, a red light-receiving element 6, a blue light-receiving element 7, and a green light-receiving element 8, are arranged horizontally. They are attached in order in the direction.
In this case, each light receiving element 6, 7, and 8 has a red filter 6a, a blue filter 7a, and a green filter 8 deposited on the end surface 5b of the slab lens 5, and a thin film light receiving element such as a photodiode is placed on top of these. It is constructed by forming elements 6b, 7b, and 8b by vapor deposition means. Lead wires 9, 10 and 11 for electrical signal transmission are attached to the three light receiving elements 6, 7 and 8, respectively.

Next, the operation of the above configuration will be described. The detection light from the object to be detected 2 is formed into an image 3 by the optical lens 1, and is incident on the end surface 5a of the slab lens 5 via the optical fiber 4 in a small area state, so-called spot state. Here, as shown in FIG. 3, the slab lens 5 functions to emit spot-shaped light from the optical fiber 4, which is incident from one end surface 5a, in a band shape from the other end surface 5b. Therefore, the end surface 5a
The detection light incident on the end surface 5b uniformly enters three light receiving elements 6, 7 and 8 for detecting the three primary colors provided on the end surface 5b.

According to this embodiment, the following effects can be obtained. That is, the detection light of the object to be detected 2 is incident on one end surface 5a of the unidirectional refractive index gradient slab lens 5 in the form of a spot through the optical fiber 4, and the three primary colors are incident on the other end surface 5b of the slab lens 5. Since three light-receiving elements 6, 7 and 8 are attached for detection, even if the object to be detected 2 becomes minute, the detection light will uniformly enter the three light-receiving elements 6, 7 and 8, and as a result, , the color of the detected object 2 can be reliably determined. Moreover, since the light receiving elements 6, 7, and 8 are attached to the end surface 5b of the slab lens 5, it is possible to reduce the size. Further, since the light receiving elements 6, 7 and 8 are attached to the end face 5b of the slab lens 5 by vapor deposition means, a solid state structure is possible.

In the above embodiment, the optical fiber 4 is used as a means for making the detection light incident on one end surface 5a of the slab lens 5 in the form of a spot, but instead, for example, as shown in FIG. 12a may be used.

Further, in the above embodiment, photodiodes were used as the thin film light receiving elements of the light receiving elements 6, 7 and 8, but phototransistors may be used instead, or conventional lenses may be used instead of the thin film light receiving elements. A light receiving element may also be used.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and it goes without saying that it can be implemented with appropriate modifications within the scope of the invention.

[Effect of idea]

As is clear from the above description, the present invention allows the detection light of the object to be detected to be incident on one end face of the unidirectional gradient index slab lens in a small area state, and
Since a plurality of light-receiving elements that detect different colors are attached to the other end face of the slab lens, even if the object to be detected is minute, the color can be reliably discriminated, and the size can be reduced. It has the excellent effect of being able to achieve the following.

[Brief explanation of the drawing]

Figures 1 to 3 show one embodiment of the present invention. Figure 1 is a schematic explanatory diagram of the overall configuration, Figure 2 is an enlarged exploded perspective view of the main parts, and Figure 3 is a unidirectional refraction diagram. FIG. 4 is a diagram corresponding to FIG. 1 showing another embodiment of the present invention, and FIGS. 5 and 6 are configuration explanatory diagrams showing different conventional examples, respectively. It is. In the drawings, 1 is an optical lens, 2 is an object to be detected, 4 is an optical fiber, 5 is a unidirectional gradient index slab lens, 5a and 5b are end faces, and 6, 7, and 8 are light receiving elements.

Claims (1)

[Claims for Utility Model Registration] 1. A unidirectional refractive index gradient slab lens that has the function of emitting light in a small area incident from one end face in a band shape from the other end face, and one end face side of this slab lens. means for making light from the object to be detected enter the one end face in a small area state, and a plurality of light receiving elements attached to the other end face of the slab lens, each of which detects a different color. Color sensor. 2. The color sensor according to claim 1, wherein the means for allowing the detection light to enter in a small area is an optical fiber. 3. The color according to claim 1 of the utility model registration claim, wherein the means for making the detection light incident in a small area is a light plate having a small light transmittance attached to one end face of the slab lens. sensor. 4 Utility model registration claims 1 to 3, characterized in that the plurality of light receiving elements are attached to the other end surface of the slab lens by vapor deposition means.
The color sensor described in any of paragraphs.