JP2014209061A - Scale - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scale which can be formed with a protection member without damaging the function of a phase grating.SOLUTION: A scale 100 includes: a phase grating 2; a cover glass 3; a groove 4; and an adhesion part 11. The phase grating 2 is formed in a phase grating formation region 21 on one surface of a substrate 1. The cover glass 3 is arranged on the phase grating 2. The adhesion part 11 is disposed in the outer periphery of the phase grating 2 on one surface of the substrate 1, and configured to adhere the substrate 1 and the cover glass 3. The groove 4 is configured to, when materials configuring the adhesion part 11 are applied, prevent the flow of the materials from the adhesion part 11 to the phase grating.

Description

  The present invention relates to a scale, for example, a scale used in an encoder.

  In an encoder used for displacement measurement, it is possible to measure the displacement between the scale and the detector by irradiating the scale with light and detecting the light reflected or transmitted by the scale with a detector. Such a scale is mounted on, for example, a stage of a measuring apparatus.

  Since the state of the scale affects the accuracy of displacement measurement, it is necessary to prevent the scale from being damaged or soiled. Therefore, a method for protecting the scale by covering the surface of the scale with a transparent protective member is known (Patent Document 1).

JP-A-2-256085

  However, the inventor has found that the above-described protected scale has the following problems. In the case of a scale using a phase grating obtained by etching glass, when the protective member is bonded on the phase grating, the phase grating is buried with an adhesive. As a result, the phase grating cannot function. On the other hand, in order to reduce the size of a device incorporating a scale, it is necessary to reduce the size of the scale. To reduce the size of the scale so that the phase grating is not filled with adhesive, the scale and protective member are bonded with sufficient strength using an adhesive or adhesive tape in the area around the phase grating, and It is necessary to prevent the adhesive member from entering the phase grating and impair the function as a scale.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a scale in which a protective member can be provided without impairing the function of the phase grating of the scale.

  The scale according to the first aspect of the present invention includes a base material, a phase grating formed in a phase grating forming region on one surface of the base material, a protective member disposed on the phase grating, and the base material. Provided on the outer periphery of the phase grating on the one surface, and an adhesive part for bonding the base material and the protective member; and when a material constituting the adhesive part is applied, from the adhesive part to the phase grating And a flow blocking means provided on the base material for blocking the flow of the material. Thereby, the flow of the bonding portion can be prevented, and the bonding member can be prevented from entering the phase grating.

  The scale according to the second aspect of the present invention is the scale described above, wherein the flow blocking means is a groove provided in the base material between the adhesive portion and the phase grating. Thereby, the flow of the bonding portion can be prevented, and the bonding member can be prevented from entering the phase grating.

  The scale according to the third aspect of the present invention is the scale described above, wherein the phase grating forming region is the flow blocking means with respect to a region other than the phase grating forming region on the one surface of the substrate. It has a predetermined level difference. Thereby, the flow of the bonding portion can be prevented, and the bonding member can be prevented from entering the phase grating.

  The scale according to the fourth aspect of the present invention is the scale described above, wherein the phase grating forming region is formed as a recess with respect to the region other than the phase grating forming region on the one surface of the base material. Is. Thereby, the flow of the bonding portion can be prevented, and the bonding member can be prevented from entering the phase grating.

  ADVANTAGE OF THE INVENTION According to this invention, the scale which can provide a protection member can be provided, without impairing the function of the phase grating of a scale.

  The above and other objects, features and advantages of the present invention will be more fully understood from the following detailed description and the accompanying drawings. The accompanying drawings are presented for purposes of illustration only and are not intended to limit the present invention.

1 is a perspective view showing an overall configuration of a scale 100 according to a first embodiment. It is a perspective view which shows the whole structure at the time of abbreviate | omitting the cover glass 3 of the scale 100 concerning Embodiment 1. FIG. It is sectional drawing of the scale 100 in the III-III surface of FIG. It is sectional drawing which shows the structure of the scale 300 which is an example of a scale when there is no groove | channel 4. FIG. It is sectional drawing in the III-III surface of FIG. 1 and 2 of the scale 100 which shows one aspect | mode when the adhesion part 11 before hardening spreads. It is a perspective view which shows the whole structure at the time of abbreviate | omitting the cover glass 3 of the scale 200 concerning Embodiment 2. FIG. It is sectional drawing of the scale 200 in the VII-VII plane of FIG. It is sectional drawing in the VII-VII plane of FIG. 6 of the scale 200 which shows one aspect | mode when the adhesion part 11 before hardening spreads.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted as necessary.

Embodiment 1
First, the scale 100 according to the first embodiment will be described. FIG. 1 is a perspective view illustrating an overall configuration of a scale 100 according to the first embodiment. The scale 100 is provided with a cover glass 3 on a substrate 1. FIG. 2 is a perspective view illustrating an overall configuration when the cover glass 3 of the scale 100 according to the first embodiment is omitted. The scale 100 further includes a phase grating 2, a groove 4, an adhesive portion 11, and a phase grating forming region 21.

  The base material 1 is a plate-like member whose longitudinal direction is the X direction in FIGS. The phase grating 2 is formed in the phase grating forming region 21 which is a part of the upper surface of the substrate 1. The phase grating 2 is constituted by a plurality of grooves whose longitudinal direction is the Y direction (the Y direction is a direction orthogonal to the X direction), for example, periodically engraved in the X direction of the substrate 1. In FIG. 1, the direction orthogonal to the X direction and the Y direction is the Z direction. The groove 4 is provided in the substrate 1 between the adhesive portion 11 and the phase grating 2. The groove 4 can be produced by laser processing (laser marking). Further, the groove 4 can be formed simultaneously with the phase grating 2 or separately by etching.

  FIG. 3 is a cross-sectional view of the scale 100 in the III-III plane of FIGS. The adhesion part 11 adheres the cover glass 3 and the base material 1 so as to surround the phase grating 2 and not to contact the phase grating 2. The adhesive part 11 is an adhesive made of a material such as an ultraviolet curable resin, which is applied in a state where it initially has fluidity, and then adheres to a member to be contacted by curing. The adhesive constituting the adhesive part 11 is first applied to a predetermined position of the substrate 1. Next, the cover glass 3 is disposed on the substrate 1. At this time, it can be assumed that the adhesive portion 11 before curing spreads in the Y direction in FIG.

  FIG. 4 is a cross-sectional view showing a configuration of a scale 300 that is an example of a scale when there is no groove 4. The scale 300 shown in FIG. 4 has the same configuration as the scale 100 except that the groove 4 is not provided. Since there is no groove 4 in the scale 300, when the adhesive part 11 before curing spreads in the Y direction, it reaches the phase grating 2 in the shortest distance, and the adhesive is sucked between the grooves of the phase grating by capillary action. There is a tendency that the phase grating is buried and the reading of the phase grating 2 is disturbed. Further, it is extremely difficult to control the amount of the adhesive so that it does not reach the phase grating 2.

  FIG. 5 is a cross-sectional view of the scale 100 taken along the line III-III in FIGS. 1 and 2 showing an embodiment in which the adhesive portion 11 before curing spreads. In this configuration, the cover glass 3 is disposed on the base material 1, and the adhesive portion 11 that flows toward the phase grating 2 flows into the groove 4 even if the adhesive portion 11 before curing spreads in the Y direction. Thereby, the flow of the adhesion part 11 is blocked by the groove 4. In other words, it can be understood that the groove 4 functions as a flow blocking means. Therefore, it is possible to prevent the bonding portion 11 from reaching the phase grating 2 and entering the phase grating 2.

  Moreover, in this structure, since the cover glass 3 is directly adhere | attached on the base material 1, the space | interval between the cover glass 3 and the phase grating 2 is kept constant, and the phase grating 2 can be read with high precision. . Furthermore, since the phase grating 2 is protected by the cover glass 3, even if dirt is attached, it is only attached to the surface of the cover glass 3. In this case, dirt can be easily removed by wiping the surface of the cover glass 3 with a solvent or the like without touching the phase grating 2.

  The groove 4 may be formed on the entire circumference of the phase grating 2 or may be partially formed around the phase grating 2.

Embodiment 2
Next, the scale 200 according to the second embodiment will be described. FIG. 6 is a perspective view showing the overall configuration when the cover glass 3 of the scale 200 according to the second embodiment is omitted. The scale 200 includes a base material 1, a phase grating 2, a cover glass 3, an adhesive portion 11, and a phase grating formation region 22. The phase grating forming region 22 is formed as a concave portion on the upper surface of the substrate 1. The phase grating 2 is formed at the bottom of the phase grating forming region 22.

  FIG. 7 is a cross-sectional view of the scale 200 on the VII-VII plane of FIG. Since the phase grating 2 is formed in the phase grating forming region 22, the step portion 24 is provided between the bonding surface 23 where the bonding portion 11 contacts the substrate 1 and the phase grating 2. The step 24 can be produced by etching, for example. Since the other structure of the scale 200 is the same as that of the scale 100 according to the first embodiment, the description thereof is omitted.

  The bonding part 11 is made of an adhesive and is applied to a predetermined position of the substrate 1. Next, the cover glass 3 is disposed on the substrate 1. Under the present circumstances, the adhesion part 11 before hardening spreads in the Y direction of FIG. FIG. 8 is a cross-sectional view of the scale 200 on the VII-VII plane of FIG. 6 showing an aspect in which the bonded portion 11 before curing spreads.

  In this configuration, even if the bonding part 11 before curing spreads in the Y direction, the bonding part 11 flowing toward the phase grating 2 flows along the step 24. Therefore, compared with the case where there is no level difference 24 (FIG. 3), the distance between the position where the adhesive portion 11 is applied and the phase grating 2 can be increased. Therefore, compared with the case where there is no level difference 24 (FIG. 3), it becomes difficult for the bonding portion 11 to reach the phase grating 2. In other words, it can be understood that the step 24 functions as a flow blocking means. Therefore, according to the present configuration, it is possible to prevent the bonding portion 11 from reaching the phase grating 2 and entering the phase grating 2.

Other Embodiments The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention. For example, the scale may have the groove 4 according to the first embodiment and the phase grating formation region 22 according to the second embodiment. In this case, it is possible to prevent the bonding portion 11 from entering the phase grating 2 more reliably. In this case, the groove 4 may be formed in any region other than the phase grating forming region 22 and the phase grating forming region 22 of the substrate 1.

  The bonding portion 11 may be formed on the entire circumference of the phase grating 2 or may be partially formed around the phase grating 2.

100, 200, 300 Scale 1 Base material 2 Phase grating 3 Cover glass 4 Groove 11 Adhesion part 21, 22 Phase grating formation region 23 Adhesion surface 24 Step

Claims (4)

A substrate;
A phase grating formed in a phase grating forming region on one surface of the substrate;
A protective member disposed on the phase grating;
An adhesive portion provided on an outer periphery of the phase grating on the one surface of the base material, and bonding the base material and the protective member;
A flow preventing means provided on the base material for preventing the flow of the material from the adhesive portion to the phase grating when a material constituting the adhesive portion is applied; and
scale. The flow preventing means is a groove provided in the base material between the adhesive portion and the phase grating.
The scale according to claim 1. The phase grating forming region has a predetermined step which is the flow blocking means with respect to a region other than the phase grating forming region on the one surface of the base material.
The scale according to claim 1 or 2. The phase grating formation region is formed as a recess with respect to the region other than the phase grating formation region on the one surface of the base material.
The scale according to claim 3.

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