JP6087646B2 - Periodic grating, periodic grating manufacturing method, and measuring device - Google Patents

Description

  The present invention relates to a periodic grating, a method for manufacturing a periodic grating, and a measuring apparatus using the periodic grating.

  Conventionally, there are incremental encoders and absolute encoders that measure position and angle. Among these, the incremental encoder has a high resolution, but since the absolute position information cannot be obtained unless the origin is first detected, the field of application is limited. On the other hand, an absolute encoder can output absolute position information instantaneously by reading a binary pattern as an image with an image sensor such as a light receiving element array or a CCD, but the resolution is not higher than that of an incremental encoder. On the other hand, there has been proposed an absolute encoder that can read incremental information and absolute information and has the advantages of these two types of encoders. In this case, simply, two light receiving element arrays for reading the incremental information and the absolute information are required, and the structure of the light receiving element and the structure of the periodic grating (scale) serving as a measurement reference are complicated. In order to simplify this structure, Patent Documents 1 and 2 disclose a periodic grating in which incremental information and absolute information are multi-valued (there are differences in transmittance and reflectance) and are alternately arranged on one track. Discloses a one-track absolute encoder. In these patent documents, incremental information and absolute information are alternately arranged on one track of a periodic grating while changing the grating height and grating depth.

International Publication No. 2008/146409 JP 2008-134235 A

  However, when manufacturing a periodic grating in which multilevel information adopted in Patent Documents 1 and 2 is manufactured, fine processing is required, and in particular, exposure and development processes using an exposure apparatus and a development apparatus are required multiple times. It becomes. This means that, for example, high-precision alignment is required a plurality of times when the exposure apparatus is used, and furthermore, a large amount of chemical solution (developer) must be used when the developing apparatus is used. . In contrast, for example, selective removal by laser power or application to a specific site using an ink jet printer can be considered to reduce the number of processes without using an exposure apparatus, etc. In this case, it is necessary to newly develop dedicated equipment and materials.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a periodic grating that is advantageous in terms of simplicity of manufacturing the periodic grating, for example.

  In order to solve the above problems, the present invention is a periodic grating including a first material, a second material, and a third material, each having a different transmittance or reflectance, and is constituted by the first material. A first lattice layer that is stacked on the first layer and is made of the second material, and is filled with the third material by the second layer; And a second grating portion that forms a space with the surface of one layer as a bottom surface, and the second grating portion is open to the outside of the periodic grating except for the surface of the second layer. And

  According to the present invention, for example, it is possible to provide a periodic grating that is advantageous in terms of simplicity of manufacturing the periodic grating.

It is a figure which shows the structure of the periodic grating which concerns on 1st Embodiment of this invention. It is a figure which shows the manufacturing process of the periodic grating which concerns on 1st Embodiment. It is a figure which shows the structure of the periodic grating which concerns on 2nd Embodiment of this invention. It is a figure which shows the manufacturing process of the periodic grating which concerns on 2nd Embodiment. It is a figure which shows the manufacturing process of the conventional periodic grating.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
First, a method for manufacturing a periodic grating and a periodic grating according to the first embodiment of the present invention will be described. Each of the periodic gratings according to the present embodiment includes at least three kinds of materials, that is, a high reflectance material, a low reflectance material, and a material having an intermediate reflectance. It is a multi-valued periodic lattice that can represent a value greater than or equal to the value. This periodic grating is, for example, an encoder (measuring device) that performs position measurement with resolution / accuracy of micron, nanometer, and sub-nanometer used for various industrial devices, or angle measurement with resolution / accuracy of angle minutes and angular seconds ) Can be applied to the scale as a measurement standard. Hereinafter, in this embodiment, as an example, it is assumed that the present invention is employed in a linear encoder that uses a reflective and straight ruler (long) scale. Furthermore, this periodic grating can also be applied as a fine optical element such as a diffraction grating or a hologram three-dimensional structure.

  FIG. 1 is a schematic perspective view showing the configuration of the periodic grating 1 according to the present embodiment. In FIG. 1, a surface on which the arrow is directed is a front surface, and a front surface in each layer described later, that is, a surface on which a lattice groove is formed is referred to as an “upper surface”. In particular, when the periodic grating 1 is applied as an encoder scale as in the present embodiment, light is irradiated toward the front of the periodic grating 1. Further, in FIG. 1 and all the following drawings, the thickness (film thickness) of each layer is exaggerated from the viewpoint of easy understanding, and the ratio of the thickness of each layer is not strict.

  The periodic grating 1 includes a plurality of layers including a substrate 2, a reflective layer 3, and a non-reflective layer 4. The material of the board | substrate 2 is selected in consideration of measurement accuracy guarantee, cost, etc. For example, it can be set as the glass with a low linear expansion coefficient suitable for obtaining high measurement accuracy. Note that if the measurement accuracy guarantee is relatively loose, it may be an inexpensive steel or resin material. Moreover, the board | substrate 2 is good also as a semi-rigid member (for example, tape-shaped member) instead of such a rigid body. The reflective layer (first layer) 3 is a layer having a high reflectance close to 100%, which is installed (laminated) on the entire upper surface of the substrate 2. As a material (first material) of the reflective layer 3, for example, aluminum or chromium can be used. The non-reflective layer (second layer) 4 is a black layer (black film) having non-reflective characteristics that is installed (laminated) on the upper surface of the reflective layer 3. As the material (second material) of the non-reflective layer 4, for example, a positive type photo paste prepared by mixing carbon black and a photosensitive resist is coated on the reflective layer 3 and then the shape is defined by patterning. It can be. In addition, as the non-reflective layer 4, what is necessary is just what can ensure desired low reflectances, such as black chrome.

  In particular, in the present embodiment, two types of grating grooves (the first grating groove 4a and the second grating groove) arranged alternately in the longitudinal direction of the entire periodic grating 1 (scanning direction when used as a scale) by the non-reflective layer 4. 4b) is formed. In addition, as shown in FIG. 1, it is arbitrary which kind of each adjacent lattice groove is formed. The first grating groove (first grating portion) 4a has a bottom surface that is deep enough to expose the reflective layer 3, and is open only on the top surface of the non-reflective layer 4, that is, faces the surface of the non-reflective layer 4. Except for is a lattice part (lattice groove, lattice hole) having a closed shape. A third material that allows the first grating groove 4a to have a desired light amount (for example, approximately 50%) of light that is incident on the light having a desired wavelength and is reflected by the reflective layer 3 A translucent layer (third layer) 5 is formed. On the other hand, the second grating groove (second grating part) 4b is the same as the first grating groove 4a in that the bottom surface of the second grating groove (second grating part) 4b is a surface having a depth at which the reflective layer 3 is exposed. Absent. That is, the second lattice groove 4b is different from the first lattice groove 4a in that the second lattice groove 4b has a region that is grooved to one or more side surfaces (surfaces other than the surface) with respect to the front surface and is open to the outside. Specifically, the second grating groove 4b corresponds to the installation position of the second grating groove 4b in a direction orthogonal to the direction in which the first grating groove 4a and the second grating groove 4b are periodically arranged. It can also be expressed as being opened with a part of the non-reflective layer 4 cut out. Further, unlike the first grating groove 4a, the second grating groove 4b is a space in which the semitransparent layer 5 is not formed, and the light incident on this portion is reflected by the reflecting layer 3 with a desired light amount (for example, substantially 90%). ) To reflect back. In addition, as long as the formation method of each grating | lattice groove | channel 4a, 4b is a method which can be processed with a desired grating | lattice width and pitch, any methods, such as machining using a semiconductor manufacturing process, drawing processing, etc., are sufficient. A specific example will be described later. As described above, in the periodic grating 1, the light incident on the front surface is reflected (non-reflected) by any region (member) of the reflective layer 3, the non-reflective layer 4, or the semi-transparent layer 5. The predetermined optical system (light receiving unit) can obtain a three-valued, that is, multi-valued reflection signal.

  Next, a method for manufacturing the periodic grating 1 will be described. First, in order to clarify the features of the present embodiment, an example of a conventional multi-valued periodic grating manufacturing process will be described as a reference. FIG. 5 is a diagram illustrating an example of a manufacturing process of a conventional multilevel periodic grating. In particular, FIG. 5A is a flowchart of the manufacturing process, and FIG. 5B shows a cross-sectional view of the periodic grating at that stage corresponding to each process of FIG. Further, in FIG. 5, from the viewpoint of ease of comparison with the periodic grating 1 of the present embodiment to be described later, the same reference numerals are given to the constituent elements corresponding to the constituent elements of the periodic grating 1 according to the present embodiment. Attached. First, the reflective layer 3 is formed on the entire top surface of the substrate 2 (step S301). As a forming method at this time, a sputtering film forming method, a vapor deposition method, a plating method, or the like can be adopted, and if the optical reflectance of the reflective layer 3 can be maintained at a desired uniformity, in particular It is not limited. Next, the non-reflective layer 4 is formed on the entire top surface of the reflective layer 3 (step S302). As a forming method at this time, there is a method of coating a non-reflective film using a positive type photo paste as described above. Here, in the present embodiment, positive type photo paste is used for patterning by light irradiation, but this is not the case when other steps (processing processes) are selected.

  Next, a predetermined lattice groove (for example, a groove closed in the planar direction like the first lattice groove 4a in the present embodiment) 20 is formed in the non-reflective layer 4 (step S303). As a formation method at this time, an L / S (line & space) pattern having an equal pitch in a groove shape is exposed to a photo paste on the substrate 2 by using an exposure apparatus. Then, after the exposure is completed, the exposed photo paste is removed with a developer using a developing device. Next, the entire surface of the non-reflective layer 4 is coated with the colored liquid m so as to fill the lattice grooves 20 (step S304). Here, the colored liquid m is a low-viscosity liquid, and finally becomes the semitransparent layer 5 by the following steps, and the material (third member) is as described above for the semitransparent layer 5. is there. Next, among the colored liquids m applied on the non-reflective layer 4 or in the lattice grooves 20, the colored liquids m other than those in the lattice grooves 20 are removed (step S305). Next, the colored liquid m present in the specific lattice groove 20 is removed so as to obtain a desired multi-value quantization periodic pattern (step S306). As a removal method at this time, there is a method of using an exposure apparatus to selectively expose a portion from which the colored liquid m is removed, and then removing the exposed portion using a developing device. Next, the colored liquid m remaining in the specific lattice grooves 20 is fixed and dried to cure (solidify) the colored liquid m (step S307). Thereby, the semi-transparent layer 5 is formed on the substrate 2, and as a result, the outermost surface is the black non-reflective layer 4, and the lattice groove 20 has either the reflective layer 3 or the semi-transparent layer 5. A ternary periodic grating is completed. As can be seen from the flow of the manufacturing process so far, conventionally, for example, two exposure and development processes are required when manufacturing a multi-value periodic grating with the same pattern of lattice (groove) shape.

  FIG. 2 is a diagram showing an example of the manufacturing process of the periodic grating 1 according to the present embodiment, corresponding to FIG. 5 related to the manufacturing process of the conventional multilevel periodic grating. Here, FIG. 2A is a flowchart of the manufacturing process, and FIG. 2B shows a cross-sectional view of the periodic grating 1 at that stage, corresponding to each process of FIG. . Note that step S101 is the same as step S301 in FIG. 5 and step S102 is the same as step S302 in FIG. After the end of step S102, next, the first grating grooves 4a and the second grating grooves 4b are formed in the non-reflective layer 4 (step S103). As a formation method at this time, it can be formed by processing using a laser illumination device in accordance with the use of the photo paste in step S102. First, the laser illuminator selectively irradiates a desired position sequentially so as to form the first grating groove 4a and the second grating groove 4b with a desired grating line width and grating pitch. The photo paste on the substrate 2 is exposed. Then, after the exposure is completed, the exposed photo paste is removed with a developer using a developing device. Here, with the use of the positive type photo paste, the developer is an alkali developer. Next, the entire surface of the non-reflective layer 4 is coated with the colored liquid m so as to fill the first lattice grooves 4a and the second lattice grooves 4b (step S104). Here, the colored liquid m is the same as that described above. At this time, since the first lattice groove 4a is a groove closed in the planar direction, the coloring liquid m is uniformly filled in the first lattice groove 4a. On the other hand, since the second lattice groove 4b is a groove that is open at least at one place in the plane direction, in this second lattice groove 4b, the colored liquid m flows out from the place little by little. Become. Next, the substrate 2 (non-reflective layer 4) is tilted at a predetermined angle (step S105). By this operation, as shown in the AA ′ cross section in FIG. 2, first, the coloring liquid m remains in the first lattice grooves 4a. On the other hand, as shown in the BB ′ cross section in FIG. 2, in the second lattice groove 4 b, the colored liquid m is collectively discharged from the portion that is open in the planar direction to the outside ( Will flow out). That is, the angle at which the substrate 2 is tilted at this time is an angle at which the coloring liquid m does not overflow beyond the non-reflective layer 4 in the first grating grooves 4a in consideration of the viscosity of the coloring liquid m, and the second grating grooves In 4b, the angle is set such that the colored liquid m adheres and is discharged without remaining. In this step, it is desirable that the coloring liquid m is completely discharged from the second lattice groove 4b. However, in the unlikely event that the coloring liquid m cannot be discharged smoothly, the coloring liquid m is discharged into the discharge region of the second lattice groove 4b. You may press the absorber (for example, sponge-like member) which absorbs. By the suction of the absorbing material, the colored liquid m can be suitably discharged from the second lattice groove 4b. Next, the inclination of the substrate 2 is returned, and the colored liquid m is fixed and dried (step S106). As a result, a semi-transparent layer 5 is formed on the substrate 2, and as a result, the second grating grooves 4 a are the reflective layer 3, the outermost surface is the black non-reflective layer 4, and the first grating grooves 4 a are semi-transparent. A ternary periodic grating having the transparent layer 5 is completed.

  As described above, in the structure of the periodic grating 1 and the manufacturing method of the periodic grating 1, when manufacturing a multilevel periodic grating with the same pattern grating (groove) shape, the manufacturing process can be simplified as compared with the conventional case. it can. That is, in the example described with reference to FIG. 5 above, conventionally, the exposure and development steps were required twice. On the other hand, in the present embodiment, as described with reference to FIG. Usually, in the exposure process, it is necessary to perform alignment with high accuracy and the like, and a certain amount of time is required for the series of processes. Further, in the development process, a chemical solution (developer) is used each time. Therefore, even if a mechanism for tilting the substrate 2 is required as in this embodiment, it is a great advantage that the exposure and development processes can be reduced. In addition, for example, it is possible to reduce the number of processes without using an exposure apparatus etc. by performing selective removal by laser power or application to a specific part using an ink jet printer. New equipment and materials need to be developed. On the other hand, this embodiment is advantageous in that it can be handled by using an existing exposure apparatus.

  In the present embodiment, the configuration of the periodic grating 1 in accordance with a scale that can be employed in a reflective encoder is illustrated. In other words, the three values represented by the periodic grating 1 are defined by portions (layers or structures) having different reflectivities. On the other hand, according to the present invention, the periodic grating can be adapted to a scale that can be employed in a transmissive encoder. In this case, the ternary values (multivalues) represented by the periodic grating are defined by portions having different transmittances. In addition, the shape of the second grating grooves 4b formed in the periodic grating 1 is shown in FIGS. 1 and 2 as described above as long as the colored liquid m can be suitably discharged as the substrate 2 is inclined. Not limited to things. For example, the second grating grooves 4b may be processed to the both side surfaces of the substrate 2, that is, the periodic grating may be crossed as it is in a direction orthogonal to the grating groove rows. Further, the periodic grating 1 may have a configuration in which a layer formed on the reflective layer 3 is a semi-transparent layer 5 and then a non-reflective layer 4 is selectively formed. In addition, in order to protect the reflectance (or transmittance) from long-term deterioration or deterioration during the process, each layer is treated with environment resistance, chemical resistance, temperature resistance, or a protective layer is added. Also good. Further, in the above embodiment, the colored liquid m is a low-viscosity liquid, but this is a high-viscosity liquid so that the colored liquid m does not enter the first lattice grooves 4a and has a discharge path. The coloring liquid m may enter the groove 4b.

  As described above, according to the present embodiment, it is possible to provide a periodic grating that is advantageous in terms of simplicity of manufacturing the periodic grating and a method for manufacturing the periodic grating.

(Second Embodiment)
Next, a method for manufacturing a periodic grating and a periodic grating according to a second embodiment of the present invention will be described. The feature of the periodic grating according to the present embodiment is that the configuration and the manufacturing method of the periodic grating 1 according to the first embodiment are changed, and in the process of discharging the colored liquid m during the manufacturing process, the substrate is not inclined. The colored liquid m is sucked from the back side of the substrate (the side without the lattice grooves).

  FIG. 3 is a schematic perspective view showing the configuration of the periodic grating 10 according to the present embodiment, corresponding to FIG. 1 showing the configuration of the periodic grating 1 according to the first embodiment. The periodic grating 10 includes a plurality of layers including a substrate 11 and a non-reflective layer 12. The material of the substrate (first layer) 11 can be, for example, a mirror stainless steel material. By selecting such a material, since the surface of the substrate 11 is a mirror surface, the substrate 11 also has a function of a reflective layer as used in the first embodiment. Furthermore, in this embodiment, the substrate 11 is formed with holes 11a penetrating from a part of the region to the back surface of the substrate 11 in all regions corresponding to the groove bottom surfaces of the second lattice grooves 12b described later. . The non-reflective layer (second layer) 12 is a black layer having non-reflective characteristics similar to the non-reflective layer 4 in the first embodiment, which is installed on the upper surface of the substrate 11.

  In the present embodiment, the non-reflective layer 12 forms two types of grating grooves (first grating grooves 12 a and second grating grooves 12 b) alternately arranged in the longitudinal direction of the entire periodic grating 10. The first grating groove (first grating portion) 12a has a bottom surface that is deep enough to expose the substrate 11, and is open only on the top surface of the nonreflective layer 12, that is, closed within the surface of the nonreflective layer 12. It is a lattice groove (lattice hole) having a shape. Then, similarly to the first embodiment, the light quantity of the light incident on the first grating groove 12a and reflected by the substrate 11 is returned to the desired light quantity (for example, approximately 50%). ) Is formed. On the other hand, particularly in the present embodiment, the second grating grooves 12b are closed within the plane of the non-reflective layer 12 while the bottom surfaces of the second grating grooves 12b are made deep enough to expose the substrate 11, as with the first grating grooves 12a. It is a lattice groove (lattice hole) having a shape. Unlike the first grating groove 12a, the semi-transparent layer 13 is not formed in the second grating groove (second grating part) 12b, and the light incident on this portion has a desired light amount (for example, substantially 90%) on the substrate 11. ) To reflect back. As described above, in the periodic grating 1, the light incident on the front surface is reflected (non-reflected) in any region of the substrate 11, the non-reflective layer 12, or the semi-transparent layer 13 that also serves as a reflection surface. The predetermined optical system can obtain a three-valued, that is, multi-valued reflection signal.

  FIG. 4 is a diagram illustrating an example of a manufacturing process of the periodic grating 10 according to the present embodiment. FIG. 4A is a flowchart of the manufacturing process, and FIG. 4B shows a cross-sectional view and a top view of the periodic grating 10 at that stage corresponding to each process of FIG. 4A. . First, the hole 11a is formed in the predetermined position of the substrate 11 (step S201). Since these holes 11a are used for sucking and discharging the colored liquid m filled in the second lattice grooves 12b described later, the positional accuracy at the time of formation is not required. Further, since the bottom surface of the second grating groove 12b in which the hole 11a is formed becomes a reflection surface, the diameter of the hole 11a is large enough to allow the colored liquid m to be sucked and not to impair the reflection function on the bottom surface. It is desirable to do so. Next, a resist film 14 having a binarized periodic pattern (a portion where the first lattice groove 12a or the second lattice groove 12b is formed and a portion where it is not) is formed on the substrate 11 (step S202). As a formation method at this time, first, a negative resist is applied to the entire surface of the substrate 11, and then a mask that has a desired lattice line width and lattice pitch is used by using an exposure apparatus. The pattern is exposed to a negative resist. Then, after the exposure is completed, the exposed portion is cured, while the resist portion that is not exposed is removed with a developer using a developing device, whereby a binarized periodic pattern is formed on the substrate 11. The resist film 14 is formed. Here, with the use of the negative resist, the developer is an organic solvent. Next, a black chromium film to be the non-reflective layer 12 is formed in a region where the resist film 14 does not exist on the substrate 11 (step S203). As a forming method at this time, for example, a plating method can be adopted. Next, the resist film 14 is stripped (removed) with a stripping solution (step S204). Next, the entire surface of the non-reflective layer 4 is coated with the coloring liquid m so as to fill the first grating grooves 12a and the second grating grooves 12b (step S205). It is assumed that the coloring liquid m is the same as that used in the first embodiment. At this time, since the first lattice groove 12a is a groove closed in the planar direction, the coloring liquid m is uniformly filled in the first lattice groove 12a. On the other hand, since the hole 11a exists in the bottom surface of the second lattice groove 12b, the colored liquid m flows out from the place little by little in the second lattice groove 4b. Next, the colored liquid m that is on the non-reflective layer 4 and has not been completely filled in the first grating grooves 12a and the second grating grooves 12b is removed with, for example, a squeegee, and then the coloring in the second grating grooves 12b is performed. The liquid m is sucked and discharged through the hole 11a by the suction pump (step S206). In addition, even if it does not use a suction pump, you may employ | adopt the method of attracting | sucking the colored liquid m only by pressing an absorber from the back surface of the board | substrate 11 to the discharge port of the hole 11a. Next, the colored liquid m is fixed and dried (step S207). As a result, a semi-transparent layer 13 is formed on the substrate 11. As a result, the bottom surface of the second grating groove 12a is a reflecting surface, the outermost surface is a black non-reflecting layer 12, and the first grating groove 12a is formed. A ternary periodic grating having the semitransparent layer 13 is completed.

  As described above, in the configuration of the periodic grating 10 and the manufacturing method of the periodic grating 10, as in the first embodiment, when the multi-valued periodic grating is manufactured in the same pattern grating (groove) shape, compared to the conventional case. The manufacturing process can be simplified. That is, also in this embodiment, as described with reference to FIG. 4, the exposure and development processes may be performed once. On the other hand, in the present embodiment, the first lattice grooves 12a and the second lattice grooves 12b have the same planar shape (lattice shape). Therefore, in the exposure process, instead of individual exposure for each grating, more general collective exposure may be performed, so that the exposure time can be further shortened. Moreover, in this embodiment, the hole 11a connected with the 2nd grating | lattice groove | channel 12b is installed in the board | substrate 11 toward the upper part of the perpendicular direction from the back surface side. Therefore, it is easy to connect a suction pump or the like to the hole 11a, and by using the suction pump, the discharge performance can be further improved from the discharge effect due to gravity + surface tension.

  In addition, the value (value shown as 90% or 50%) regarding the transmittance | permeability or reflectance shown in said each embodiment is an example, Comprising: It can change suitably. Further, in each of the embodiments described above, the periodic grating 1 (10) has a three-value configuration in which the transmitted light amount or the reflected light amount is a theoretical value of 100% and 50% in addition to the non-reflecting surface. However, the present invention is not limited to this, and can also be applied to a configuration having three or more values (for example, four values of 100%, 75%, 50%, and 25% as theoretical values).

(Measurement device)
Next, a measuring apparatus according to an embodiment of the present invention will be described. The measurement apparatus according to the present embodiment includes a scale serving as a measurement reference, a light projecting unit that irradiates light to the scale, and a light receiving unit that receives light transmitted through the scale or light reflected from the scale. It is a so-called encoder that measures position or angle. In particular, the measurement apparatus according to the present embodiment can employ the periodic grating of the above-described embodiment as a scale. Here, in the above-described embodiment, the scale has been described as being adopted as a linear ruler linear encoder as an example. . The measurement device according to the present embodiment is advantageous in at least one of the quality, productivity, and production cost of the article as compared with the conventional method.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 1 Periodic grating 3 Reflective layer 4 Non-reflective layer 4a 1st grating groove 4b 2nd grating groove

Claims (10)

A periodic grating including a first material, a second material, and a third material, each having a different transmittance or reflectance,
A first layer composed of the first material;
A second layer stacked on the first layer and configured of the second material,
The second layer includes a first lattice portion filled with the third material, and a second lattice portion that forms a space with the surface of the first layer as a bottom surface.
In the second grating part, a part other than the surface of the second layer is opened to the outside of the periodic grating.
A periodic grating characterized by that.   The second grating part is opened in a state in which a part of the second layer is cut away in a direction orthogonal to a direction in which the first grating part and the second grating part are periodically arranged. The periodic grating according to claim 1, wherein:   2. The periodic grating according to claim 1, wherein the second grating part is opened by a hole penetrating from the surface of the first layer, which is a bottom surface of the second grating part, toward the outside. .   The said 1st grating | lattice part is open | released with respect to the surface of the said 2nd layer, and is closing except the surface of the said 2nd layer, The any one of Claim 1 thru | or 3 characterized by the above-mentioned. Periodic grating. The scale which has a periodic grating of any one of Claims 1 thru | or 4. A method of manufacturing a periodic grating including a first material, a second material, and a third material, each having a different transmittance or reflectance,
Laminating a second layer composed of the second material on a first layer composed of the first material;
Forming a first lattice portion in the second layer;
Forming a space in the second layer with the surface of the first layer as a bottom surface, and forming a second grating portion in which a portion other than the surface of the second layer is open to the outside of the periodic grating; ,
Filling the first lattice part and the second lattice part with the liquid third material;
Discharging the third material in the second lattice part from the portion opened to the outside after the filling of the third material with liquid is completed;
including,
A method for producing a periodic grating . The second grating part is opened in a state in which a part of the second layer is cut away in a direction orthogonal to a direction in which the first grating part and the second grating part are periodically arranged. And
In the step of discharging the third material, the third material is caused to flow out to the outside by inclining the second layer in a direction in which a part of the notched second layer is directed. A method for manufacturing a periodic grating according to claim 6 . The second lattice portion is opened by a hole penetrating from the surface of the first layer, which is the bottom surface of the second lattice portion, toward the outside,
The method for manufacturing a periodic grating according to claim 6 , wherein, in the step of discharging the third material, the third material is sucked from the hole. And in the third material discharging step, the manufacturing method of the periodic grating according to any one of claims 6 to 8, characterized in that devote absorbing material portion being the open. A measuring device for measuring position or angle,
The scale that is the measurement standard,
A light projecting unit that emits light to the scale;
A light receiving unit that receives light transmitted through the scale or light reflected from the scale;
Including
The scale has the periodic grating according to any one of claims 1 to 4.
A measuring device characterized by that.

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