JPH04116727U - optical encoder - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an optical encoder that accurately aligns the slit of a fixed slit plate and the photosensor chip of a photosensor board, and allows easy assembly of the fixed slit plate and the photosensor board. . [Configuration] Fixed slit plate 101 and photosensor board 20
1 are provided with reference patterns or reference holes, and by aligning or fitting the pins 301 with these reference patterns or holes, the fixed slit plate and the photosensor board are aligned, and the stepped portion of the pin 301 aligns the two. This is a configuration that determines the interval between. [Effect] The positional relationship between the slit on the fixed slit plate and the photosensor chip on the photosensor substrate can be determined with the precision of pattern creation, and the positional accuracy of both is good. Assembly is easy because parts can be arranged by fitting pins and holes.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention is an optical encoder structure equipped with a fixed slit plate and a photosensor board. Regarding.

0002

[Conventional technology]

FIG. 6 shows the optical system of a general optical encoder. The light emitted from the light source 601 is , Slit A of the rotating slit plate 603 (605, the slit is shown in black on the drawing) (However, in reality, the black part is the transparent part and the white part is the light blocking part), and the slit of the fixed slit plate 607 is The photosensor chip passes through the lit B (609) and is placed on the photosensor board 611. 613 is reached. The photosensor chip 613 generates a signal according to the amount of light input. is output as a position signal.

0003 In order to detect the absolute position, position detection is performed on concentric tracks on the rotating slit plate. For encoders with multiple code patterns for output, the Signals can interfere with each other and, in the worst case, become undetectable. . The cause of this is the slit of the fixed slit plate and the photosensor on the photosensor board. One example of this is that the positional relationship of the sensor chips is not shown accurately. For example, one frame Two strips on adjacent tracks of the fixed slit plate are placed on the photo sensor chip. Naturally, when the lit is located, a composite signal of both is output from the photosensor chip. be done. Therefore, the slit of the fixed slit plate and the photosensor on the photosensor board are It is necessary to accurately determine the positional relationship of the sensor chips and assemble them.

0004 Additionally, the fixed slit plate and photosensor board are arranged perpendicular to the optical axis of the light source. Therefore, the fixed slit plate and the photosensor board should be parallel to each other. Good things are required.

[0005] Alignment of the slit on the fixed slit plate and the photosensor chip on the photosensor board The alignment has a large effect on the interference of signals from adjacent tracks, but conventionally I took the method shown below. FIG. 7 is a sectional view of a main part, and FIG. 8 is a plan view. Fixed The slit plate 703 and the photosensor board 705 are fixed with adhesive or the like. It is attached to the top plate base 701. First, fix the photo sensor board 705 on the Attach it to the slit plate base 701 and check the slits of the fixed slit plate 703 by visual inspection or other methods. The position of the lit 801 and the photosensor chip 707 on the photosensor board 705 is Then, the fixed slit plate 703 is attached to the fixed slit plate base 701.

[0006] However, with this method, the influence of the thickness of the fixed slit plate 703 cannot be ignored, and the parallax This causes an error. Also, a photo is inserted through the slit 801 of the fixed slit plate 703. Positioning by looking into the sensor chip 707 is generally done when the width of the slit 801 is Due to the narrowness of several tens of micrometers, which is difficult to do, we fixed the slit plate base 70 in advance. 1. A reference plane is provided on each of the fixed slit plate 703 and the photosensor board 705, A method such as positioning using the reference plane has been used.

[0007]

[Problem that the idea aims to solve]

However, in the conventional method, only one set of reference planes is provided, as shown in Figure 8. Not kicked. This is the position in the direction of arrow 803 in addition to the reference plane on the left side of FIG. This is because machining would be troublesome to create a reference surface for determination. Therefore, arrow 8 Positioning in the 03 direction cannot be performed accurately. In addition, the fixed slit plate 703 The parallelism in the height direction of the photosensor substrate 705 and the fixed slit plate base 701 Machining of the fixed slit plate base 701 is difficult because it depends on the machining accuracy. Ru. Furthermore, a fixed slit plate base 701, a fixed slit plate 703, a photo sensor In order to provide a reference plane on each of the support substrates 705, the fixed slit plate 703 has a slit. Positioning accuracy of photosensor chip 707 between photo sensor board 705 and photo sensor board 701 is likely to go down. As a result, there is no optical influence from adjacent tracks. It was difficult and difficult to assemble in this way. Also, the slit Check whether the positioning of the photosensor chip 801 and the photosensor chip 707 is accurate. It is difficult to determine the positioning until the output is actually taken out from the photosensor chip 707. If it is not accurate and you cannot get the correct output signal, you will have to reassemble it from scratch. I had to. The purpose of this invention is to solve the above problems and to slit the fixed slit plate. It is easy to accurately align the photosensor chip on the photo sensor board and the photo sensor board. The purpose of the present invention is to provide an optical encoder that can perform

[0008]

[Means to solve the problem]

In order to achieve the above object, the present invention provides a photosensor chip on a photosensor substrate. A plurality of positioning reference holes are provided using the top as a position reference. Also, fixed slit plate On the top, multiple positioning reference patterns or Provide a positioning reference hole. These positioning reference holes or positioning reference patterns Determine the position of the fixed slit plate and photosensor board using a ring etc. and multiple pins. and assemble it.

[0009]

[Effect]

The position of the above positioning reference pattern or positioning reference hole is relatively accurate. The slits on the fixed slit plate and the photosensor on the photosensor board can be The position of the chip can be adjusted accurately. Also, it is fixed with the photo sensor board. Relatively easy assembly by arranging slit plates using pins I can do it.

0010

【Example】

<Example 1> Embodiments of the present invention will be described below with reference to the drawings. Figures 1, 2, and 3 are A diagram showing an example of the fixed slit plate and photosensor board of the encoder according to the present invention. It is. In Figure 1, 101 is a fixed slit plate, 103 is a slit, and 105 is a pin insertion plate. This is the reference hole A for inserting. The fixed slit plate 101 has a light shielding pattern on the glass plate. Generally, the slit part is made transparent by forming a coating and omitting the coating at the slit part. However, there are also ones made from thin metal plates with actual slits. In Figure 2, 201 is a file Photo sensor board, 203 is a photo sensor chip, 205 is for inserting a pin This is the reference hole B. In addition, 301 in FIG. 3 indicates the fixed slit plate 101 and the photo sensor. This is a pin that also serves as a positioning pin for coupling with the substrate 201.

[0011] The reference hole A (105) in Fig. 1 is for the pin that was previously formed at the same time as the slit pattern. Open it based on the pattern. Since it is a pattern reference, use reference hole A (105). The positional relationship of the slits 103 can be determined relatively accurately. Similarly, Figure 2 The reference hole B (205) is based on the pin pattern created at the same time as the circuit pattern. Leave it open. As a result, the reference hole B (205) and the photosensor chip 203 The positional relationship can be determined with an accuracy of several tens of micrometers. Slit 103 and fo The positional relationship of the sensor chip 203 only needs to have an accuracy of about 0.1 mm, so The method described above is accurate enough. In Figure 3, first, pin 301 is The sensor board 201 is inserted into four reference holes B (205) and fixed with adhesive or the like. Next, insert the four reference holes A (105) of the fixed slit plate 101 and the photosensor base. Align the position with the pin 301 on the plate 201 and push it in, and then attach it to the fixed slit plate 101. The photosensor substrate 201 is bonded. After that, the fixed slit plate 101 and the pin 30 Fix 1 with adhesive or the like.

0012 <Example 2> Next, a second embodiment of the present invention will be described. In Figure 4, 401 is a fixed slit plate , 403 is a slit, and 405 is a reference pattern for determining the pin position. . The photosensor substrate is the same as that shown in FIG. 2 above. FIG. 5 is an assembled sectional view, and 501 is A positioning pin that connects the fixed slit plate 401 and the photosensor board 201 It is.

[0013] The reference pattern 405 is created in advance at the same time as the slit pattern. The positional relationship with the lit 403 can be determined accurately. Similarly, reference hole B in Fig. 2 The positional relationship between (205) and the photosensor chip 203 should also be expressed relatively accurately. I can do it. In FIG. 5, first, place the pins 501 at four bases on the photosensor board 201. Insert into semi-hole B (205) and fix with adhesive or the like. Next, the fixed slit plate 401 on the four reference patterns 405 and on the pin 501 on the photosensor board 201. Align the edges visually, fix with adhesive, and connect the fixed slit plate 401 and the photosensor base. Boards 201 are joined together.

[0014] In either of the above two embodiments, the slits of the fixed slit plate and the photosensor The photosensor chip on the sensor board can be positioned accurately and easily. .

[0015]

[Effect of the idea]

The positions of the slit and photosensor can be determined with the accuracy of pattern creation, so both The positioning accuracy of the operator is good. In Example 1, the positioning is done by fitting the pin and the hole. Since it can be placed anywhere, it is easy to assemble. In the second embodiment, the reference pattern 405 is fixed. Since they are placed at the four corners of the fixed slit plate 401, errors due to parallax caused by visual inspection are eliminated. By using the reference pattern 405 and the pin 501, the slit 403 and The position of the photosensor chip 203 can be easily adjusted. Also, in Figure 3 By changing the dimensions of the stepped portion of the pin 301, the fixed slit plate 101 and the photo sensor can be The distance between the fixed slit plate 101 and the photo sensor substrate can be freely selected. The parallelism of the plate 201 can be easily increased.

[Brief explanation of drawings]

FIG. 1 is a plan view of a fixed slit plate that is an embodiment of the present invention.

FIG. 2 is a plan view of a photosensor substrate that is an embodiment of the present invention.

FIG. 3 is an assembled sectional view of the fixed slit plate of FIG. 1 and the photosensor substrate of FIG. 2;

FIG. 4 is a plan view of a fixed slit plate according to another embodiment of the present invention.

5 is an assembled sectional view of the fixed slit plate of FIG. 4 and the photosensor substrate of FIG. 2; FIG.

FIG. 6 is a diagram showing a general optical system of an optical encoder.

FIG. 7 is a front view showing an assembled state of a conventional fixed slit plate and a photosensor board.

FIG. 8 is a plan view showing an assembled state of a conventional fixed slit plate and a photosensor substrate.

[Explanation of symbols]

101 Fixed slit plate 103 slit 105 Reference hole A 201 Photosensor board 203 Photo sensor chip 205 Reference hole B 301 pin 401 Fixed slit plate 403 slit 405 Standard pattern 501 pin 601 Light source 603 Rotating slit plate 605 Slit A 607 Fixed slit plate 609 Slit B 611 Photo sensor board 613 Photo sensor chip 701 Fixed slit plate base 703 Fixed slit plate 705 Photo sensor board 707 Photo sensor chip 709 Reference plane 801 slit

Claims (2)

[Scope of utility model registration request] Claim 1: In an optical encoder equipped with a fixed slit plate and a photo sensor substrate, the fixed slit plate is provided with a plurality of positioning reference patterns or positioning reference holes whose positional relationship with the slits is clear, and the photo sensor substrate is provided with a plurality of positioning reference patterns or positioning reference holes. By providing a plurality of positioning reference holes whose positional relationship with the sensor chip is clear and aligning the positioning reference patterns or positioning reference holes using a plurality of positioning pins, the fixed slit plate and the photosensor board can be aligned. An optical encoder characterized by positioning. 2. The optical encoder according to claim 1, wherein the distance between the fixed slit plate and the photosensor substrate is determined by a stepped portion of the positioning pin.