JPS62148815A - Plate for optical encoder - Google Patents

Abstract

PURPOSE:To easily high dimensional accuracy with regard to a slit and a guide hole by providing the slit which is formed in the peripheral edge part of a plate body in one body and where a light beam passes and the guide hole for alignment which is formed integrally in the center part of the plate body. CONSTITUTION:The plate body 1 has a code plate molded out of plastic or glass which is opaque enough not to pass the light of, for example, a light emitting diode and the peripheral edge part 1a of the plate body 1 having the slit 2 is improved more in size accuracy and formed thinly so as to reduce the influence of light interference and diffraction while the center part 1b is formed thickly so as to secure the strength. A light emitting part emits light to a light receiving part and when a plate for an optical encoder rotates, the light passes through only the slit 2, so the light is received by the light receiving part as a pulses the this light signal is converted into an electric signal by the light receiving part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a plate for an optical encoder.

[Background technology]

An optical encoder includes a light emitting section such as a light emitting diode (LED), a light receiving section such as a photodiode, and an optical encoder plate including a code plate having a slit and a phase plate.

By the way, the conventional optical encoder plate used in a small, high-resolution rotary encoder with an output pulse number of about 2,000 is first deposited with chromium on the surface of a glass substrate, and then photo-etched to form a microscopic plate to allow light to pass through. The manufacturing process involved forming a groove and then cutting the glass substrate into a donut shape to form a centering guide hole in the center of the glass substrate.

However, while the dimensional accuracy of the slit is ±0.021cm due to photoetching, the dimensional accuracy of the guide hole is only about ±0.1cm. etc., the concentricity of the optical encoder plate cannot be obtained sufficiently, and therefore, minute position adjustment work is required. As a result, assembly costs have increased and optical encoders have become expensive.

[Purpose of the invention]

An object of the present invention is to provide a plate for an optical encoder that can easily obtain high dimensional accuracy in both the slit and the guide hole and can be made inexpensive.

[Disclosure of the invention]

The optical encoder plate of the present invention includes a plate body, a slit integrally formed on the peripheral edge of the plate body to allow light to pass through, and a centering guide hole integrally formed in the center of the plate body. It is equipped with the following.

According to the configuration of the present invention, since the slits and guide holes are integrally molded when the plate main body is molded, it can be manufactured with submicron level dimensional accuracy without the need for post-processing using molding means using a mold. . Therefore, the conventional position adjustment work is no longer necessary, and the assembly cost can be reduced, and the manufacturing process is extremely easy due to the reduction in the number of steps and molding process, and the cost can be reduced by mass production.

Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 to 4. That is, this optical encoder plate includes a plate body 1, a slit 2 integrally molded on the peripheral edge of the plate body 1 to allow light to pass through, and a centering slit integrally molded in the center of the plate body 1. guide hole 3.

The plate body 1 is an example of a code plate, and is made of, for example, an opaque plastic or glass molding material that does not allow light from a light emitting diode to pass through. Further, the peripheral edge portion 1a of the plate body 1 having the slit 2 is formed to be as thin as, for example, about 0.3 fi in order to further improve dimensional accuracy and reduce the effects of light interference and diffraction. On the other hand, the central portion 1b is formed to have a thickness of approximately 1 to 3 fl to ensure strength. 4 is a mounting hole, and FIG. 4 shows the state in which the optical encoder is in use, 5 is a light emitting section using, for example, a light emitting diode, and 6 is a light receiving section using, for example, a photodiode.

Light is emitted from the light emitting part 5 to the light receiving part 6 as shown by the arrow, and when the optical encoder plate (A) rotates, the light passes only through the slit 2, so the light is received by the light receiving part 6 in a pulsed manner. Become. This optical signal is converted into an electrical signal by the light receiving section 6.

With this configuration, in the optical encoder plate of this embodiment, the slits 2 and guide holes 3 are precisely molded with high precision by the molding means.

Therefore, when mounting the optical encoder plate on the optical encoder, there is no need to perform fine position adjustment processing as in the conventional case. As a result, assembly costs can be reduced, and optical encoders can be realized at low cost through mass production using die molding.

A second embodiment of the invention is shown in FIG. That is, in this optical encoder plate, the plate body 1 is molded from a transparent material, and the lattice portion 8 between the slits 2
The side facing the light emitting part 5 is formed into a reflective inclined surface 7. Therefore, the light from the light emitting part 5 is reflected as shown by the arrow on the inclined surface 7 without passing through the lattice part 8, so the slit 2
Only this light can be transmitted by the light receiving section 6.

Note that although the above embodiments were directed to code plates, phase plates may also be formed in the same manner.

〔Effect of the invention〕

According to the optical encoder plate of the present invention, since the slits and guide holes are integrally molded when the plate body is molded, it can be manufactured with submicron level dimensional accuracy without the need for post-processing using molding means. can do. This eliminates the need for conventional position adjustment work, which reduces assembly costs, and also makes manufacturing extremely easy due to a reduction in the number of steps and molding, and makes it possible to reduce costs through mass production.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the first embodiment of the present invention, Fig. 2 is a sectional view thereof, Fig. 3 is a partially enlarged plan view, Fig. 4 is a sectional view of the first embodiment of the invention, and Fig. 5 is a sectional view of the second embodiment. FIG. 3 is a cross-sectional view of the example in use. l...Plate body, 1a...periphery, tb...
Center part, 2...Slit, 3...Guide hole Figure 4 Figure 5 - Clause Procedure Reifu Seisho (Spontaneous) 1. Hanyu's Fuji R ■060 Patent Application No. 289771 2, Name of the invention Plate for optical encoder 3, Person making the amendment Relationship with Hanyu Applicant 4, Agent 5, Date of amendment order Page 4 In the 18th line, the statement "r about 0.3 mm" is corrected to "about 0.1 to 0.3 mm".

Claims (3)

[Claims] (1) For an optical encoder comprising a plate body, a slit integrally molded on the peripheral edge of the plate body to allow light to pass through, and a centering guide hole integrally molded in the center of the plate body. plate. (2) The peripheral edge portion of the plate body is formed thinly, and the central portion is formed thickly.
Plate for optical encoder described in ). (3) The optical encoder according to claim (1), wherein the plate main body is transparent, and the side of the grid section between the slits facing the light emitting section is a reflective inclined surface. plate.