JPH03199931A - Optical sensor - Google Patents

Abstract

PURPOSE:To obtain a plurality of detecting regions for one Fresnel-lens surface by deflecting an optical axis for the detecting regions to a plurality of different angles. CONSTITUTION:Surface parts 11a and 11b of linear multiple prisms are fromed at the front surface of an optical member 11. The prism-surface parts 11a and 11b are symmetrical with respect to an optical axis O - O' and formed at the uniform same angle. One Fresnel-lens part 1c is formed at the rear surface of the member 11. A light emitting element 12 is arranged at the rear side of the member 11. The optical axis of the element 21 is perpendicular to the Fresnel-lens part 11c. In this constitution, the luminous flux from one light emitting element 12 is divided into the upper and lower parts through the prism- surface parts 11a and 11b after the luminous flux has passed through the Fresnel-lens part 11c. Thus, the luminous fluxes can be projected on detecting regions 13a and 13b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical sensor that detects objects and the like.

[Conventional technology]

Conventionally, such an optical sensor is configured as shown in FIG. 4, for example.

The optical sensor 1 is composed of a split mirror 3 formed in a concave shape as a whole and a light emitting element 4 disposed to face the split mirror 3.

When the light flux from this light emitting element 4 is incident on the split mirror 3, each mirror portion 3a is divided into individual mirrors 3a.

By being reflected by 3b and 3c, three detection areas 5a, 5b, and 5c arranged in the longitudinal direction are irradiated. That is, the detection area is divided using split mirrors.

When an object or the like moves within the detection w4 areas 5a, 5b, and 5c, these detection areas 5a.

By detecting variations in the amount of light from 5b and 5c with a light receiving element (not shown) and appropriately processing the output signal of the light receiving element, it is possible to detect the presence or absence of the object etc. in each detection area 5a, 5b, 5c, respectively. Movement is now detected.

[Problem to be solved by the invention]

By the way, in the optical sensor 1 configured in this way, one mirror portion 3a, 3b, 3c is required for each detection area 5a, 5b, 5c, and each mirror portion 3a, 3b, 3c has problems in that the processing steps are complicated and time consuming, and the manufacturing cost increases because each material is processed independently.

Furthermore, instead of the split mirror 3, a plurality of lenses are used to direct the light flux from the light emitting element 4 to each detection area 5a.
Similarly, in the case of a configuration that leads to +5 b and 5 c, one lens is required for each detection area, which increases the number of parts, and the assembly is complex and time-consuming, increasing manufacturing costs. There was a problem.

In view of the above points, an object of the present invention is to provide an optical sensor that can reduce manufacturing costs by providing a plurality of detection areas with one optical element and optical member.

[Means for Solving the Problems] According to the optical sensor of the present invention, the front surface is sequentially formed as prism surface portions having different angles along the longitudinal direction, preferably linear multi-prisms or flat portions,
This is achieved by comprising a plate-shaped optical member whose rear surface is formed as one Fresnel lens surface portion, and an optical element consisting of one light-emitting element or light-receiving element arranged behind this optical member. be done.

In addition, a plurality of plate-shaped optical members each having a front surface sequentially formed as a prism surface portion or a plane portion having different angles along the longitudinal direction and a rear surface formed as one Fresnel lens surface portion; and one optical element disposed at the rear.

[For production]

According to the above configuration, the optical axis relative to the detection area is deflected to a plurality of different angles by the action of each prism surface portion of the optical member, or is transmitted through the flat surface portion of the optical member as it is, so that the optical axis of the optical member A single Fresnel lens surface is provided with multiple detection areas in which the presence or movement of an object should be detected.

In addition, since the optical member is relatively easy to process, and the two optical elements, the prism and Fresnel lens, are integrally constructed as an optical member, it is possible to downsize the prism and the Fresnel lens. There is no need to align the Fresnel lens. Further, since only one optical element is required, the number of parts is reduced, and manufacturing costs can be reduced.

According to the above other configuration, the optical axis relative to the detection area is deflected based on the action of each prism surface portion or plane portion of each optical member, or is transmitted as is, so that
For only one Fresnel lens portion of each optical member, a plurality of detection areas for detecting the presence or movement of an object are provided along the longitudinal direction of the optical member.

Processing of the above-mentioned optical member is relatively easy, and the two optical elements, the prism and Fresnel lens, are integrated as an optical member, which allows for miniaturization and eliminates the need to align the prism and Fresnel lens. Furthermore, since only one optical element is required for each optical member,
The total number of parts is reduced, and manufacturing costs can be reduced.

〔Example〕

Hereinafter, embodiments of the optical sensor of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 shows an embodiment of the optical sensor of the present invention, and the optical sensor 10 includes a plate-shaped optical member 11 and a light-emitting element disposed behind the optical member 11 in terms of its light-emitting part. It consists of 12.

The plate-shaped optical member 11 has a front surface formed sequentially as a linear multi-prism surface portion 11a along its longitudinal direction and a linear multi-prism surface portion 11b having a different angle from this linear multi-prism surface portion 11a, and a rear surface formed as a linear multi-prism surface portion 11b having a different angle from the linear multi-prism surface portion 11a. It is formed as a Fresnel lens portion 11c.

That is, the linear multi-prism surface section 11a and the linear multi-prism surface section 11b are formed at symmetrical angles with respect to the optical axis O-0'. These linear multi-prism surface portions 11a and linear multi-prism surface portions 11
b are formed at the same -like angle.

Further, the light emitting element 12 is disposed such that its optical axis is perpendicular to the Fresnel lens portion 11c of the optical member 11.

The optical sensor 10 of the present invention is configured as described above, and after the light beam from the light emitting element 12 passes through the Fresnel lens portion 11c of the optical member 11, it is affected by the action of each linear multiprism surface portion 11a, Ilb. In the illustrated case, the linear multi-prism surface portion 11a is deflected upward and associated with the detection region 13a, and the linear multi-prism surface portion 11b is deflected downward and associated with the detection region 13b. .

Because of this relationship, after the light beam from only one light emitting element 12 passes through the Fresnel lens portion 11c of the optical member 11, it is transmitted by each linear multiprism surface portion 11a, llb of this optical member 11. Divided into upper and lower sections, two detection areas 13 a and 13 b
will be irradiated.

FIG. 2 shows another embodiment of the optical sensor of the present invention, in which the optical sensor 20 includes a plate-shaped optical member 21 and a light-emitting device disposed behind the optical member 21 with respect to its light-emitting portion. It is composed of an element 22.

The plate-shaped optical member 21 has a front surface sequentially formed along its elongated direction as a linear multiprism surface portion 21a, a flat surface portion 21b, and a linear multiprism surface portion 21c having a different angle from the linear multiprism surface portion 21a, and a rear surface thereof. is formed as one Fresnel lens portion 21d.

That is, the linear multi-prism surface section 21a and the linear multi-prism surface section 21c are formed at symmetrical angles with respect to the optical axis O-0'. These linear multi-prism surface portions 21a and linear multi-prism surface portions 21
c are formed at the same -like angle.

The optical member 21 is disposed such that its optical axis is perpendicular to the Fresnel lens portion 21d.

Another optical sensor 20 of the present invention is configured as described above, and the light beam from the light emitting element 22 is transmitted to the optical member 2.
After passing through one Fresnel lens section 21d, each linear multiprism surface section 21a.

21c or the flat part 21b, in the illustrated case, the linear multiprism surface part 21a is deflected upward to be associated with the detection area 23a, and the flat part 21b is transmitted as it is, so that it is connected to the detection area 23b. The linear multi-prism surface portion 21c is further deflected downward,
It is associated with the detection area 23c.

Because of this association, after the light beam from only one light emitting element 22 passes through the Fresnel lens section 21d of the optical member 21, it passes through each linear multiprism section 21a of the optical member 21.

21c and the flat part 21b, the light is divided into three parts vertically, and three detection areas 23a, 23b, and 23c are irradiated.

3 shows an example of application of the embodiment shown in FIG. 1 and FIG. 2, respectively. In FIG. 3(A), three optical members 11 in FIG. 1 are arranged side by side, and , one light emitting element 12 is provided for each optical member 11.

Six detection areas 31a are each divided into two by each linear multi-prism section 11a, llb of the optical member 11 by three light emitting elements 12 provided for each of the optical members 11.

3 l b, 31 c, 31 d, 31
e, 31 f are given.

Further, in FIG. 3(B), two optical members 21 in FIG. 2 are arranged side by side, and one light emitting element 22 is provided for each optical member 21.

Six detection areas 41a, 41b are divided into three by each linear multiprism part 21a, 21c and flat part 21b of the optical member 2I by three light emitting elements 22, one each provided for the optical member 21. , 4
1c, 41d, 41e.

41f is given.

In the above explanation, all optical elements are light-emitting elements, but this is not limited to the case where the optical elements are light-receiving elements. It is clear that the effects are similar. Similar effects can also be obtained when a pyroelectric infrared sensing element is used as the light receiving element.

〔Effect of the invention〕

As described above, according to the optical sensor of the present invention, by providing a plurality of detection areas with one optical element and optical member, manufacturing costs can be reduced and the entire sensor can be miniaturized. Demonstrates excellent effects.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the optical sensor of the present invention, (A)
is a schematic cross-sectional view 5, (B) is a rear view of the optical member, (C
) shows a front view of the optical member, FIG. 2 shows another embodiment of the optical sensor of the present invention, and (A
) is a schematic sectional view thereof, (B) is a rear view of the optical member, (C) is a rear view of the optical member.
3(A) is a schematic sectional view showing an example of application of the optical sensor in FIG. 1; FIG. 3(B) is a schematic sectional view showing another example of application of the optical sensor in FIG. 1. Cross-sectional view FIG. 4 is a schematic cross-sectional view showing an example of a conventional optical sensor. 10.20, 30.40... Optical sensor; 11゜2
1...Optical member; lla, Ilb, 21a, 2
1c... Linear multi-prism part; 21b... Planar part; 11c, 21d-... Fresnel lens part; 12,
22... Light emitting element; 13a, 13b, 23a, 23b
. 23c, 31a to 31f, 41a to 41f--detection area.

Claims (2)

[Claims] (1) A plate-shaped optical member whose front surface is sequentially formed as a prism surface portion or a plane portion with different angles along the longitudinal direction, and whose rear surface is formed as one Fresnel lens surface portion, and a plate-shaped optical member disposed at the rear of the optical member. 1. An optical sensor comprising: one optical element provided with an optical sensor. (2) A plurality of plate-shaped optical members each having a front surface sequentially formed as a prism surface portion or a plane portion having different angles along the longitudinal direction, and a rear surface formed as one Fresnel lens surface portion; 1. An optical sensor comprising: one optical element disposed at the rear.