JP2006337641A - Method for producing prism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce prisms having high angular accuracy. <P>SOLUTION: Tabular large substrates 1 and small substrates 2 having the same width and thickness as the large substrate 1 but having a smaller depth than the large substrate 1 are prepared. A dielectric multilayer film 3 is formed on one surface of each substrate. The large substrates 1 and the small substrates 2 are alternately stacked in such a way that they are made stepwise with a dislocation corresponding to the thickness in a width direction and both ends of the large substrates 1 are exposed as reference planes B in a depth direction. The resulting stacked glass body 4 is cut in a direction parallel to the steps and the cut surfaces of cut multiple glass bodies 5 are polished. The multiple glass bodies 5 are then cut in a vertical direction to obtain strip glass bodies 6 and the cut surfaces of the strip glass bodies 6 are polished. At this time, by polishing the cut surfaces with the exposed reference planes B as standards, the polished surfaces can be made strictly 45° to the reference planes B. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a prism.

  As a component of an optical system typified by an optical pickup device, for example, there is a polarization beam splitter. A polarization beam splitter is an optical element that separates laser light emitted from a light source into reflected light and transmitted light. Either reflected light or transmitted light is directed to an optical disk, and the other light is laser light. Toward the APC (Auto Power Control) light receiving element for intensity detection. Since the reflected light reflected by the polarizing beam splitter is generally reflected at an angle of 90 °, the polarization separation film constituting the polarizing beam splitter is arranged to make an angle of 45 ° with respect to the optical axis. Accordingly, a cube-shaped prism is used as the polarization beam splitter, and the polarization separation film is formed on the prism at an angle of 45 ° with respect to the optical axis.

For example, Patent Document 1 discloses a method of manufacturing an optical device (prism) in which a polarization separation film is formed at a predetermined angle. In Patent Document 1, a plurality of identical plate glasses are prepared, and after laminating these plate glasses in a staircase shape to obtain a laminate, the laminate is cut into divided laminates, and lamination and cutting of the divided laminates are repeated. Go and get the final prism. At this time, in order to obtain an optical device in which the polarization separation film is formed at a predetermined angle inside the prism, the divided laminate is obtained by cutting the laminate along an inclined side wall having an angle corresponding to the inclination angle of the polarization separation film. Are arranged in a staircase pattern.
JP 2000-199810 A

  By the way, the dielectric multilayer film (polarization separation film referred to in Patent Document 1) formed on the finally manufactured prism must be formed with extremely high angular accuracy with respect to the light incident surface. . Therefore, when manufacturing a prism, a dielectric multilayer film must be formed with extremely high angular accuracy. However, in the invention of Patent Document 1, it is difficult to satisfy the high angular accuracy required for the prism.

  That is, in the invention of Patent Document 1, when a plurality of plate glasses and a divided laminate are laminated, an adhesive is applied and bonded between the respective plate glasses. At this time, a thickness error may occur in the adhesive of each layer. Since a plurality of adhesives are laminated, the thickness error of the adhesive in each layer is accumulated. In addition, since the stacking and cutting of the plate glass and the divided laminated body are repeatedly performed, the accumulated error further accumulates, and a cutting error also occurs at the time of cutting. It will contain. Further, the plate glass and the laminated divided body are arranged stepwise along the inclined wall, but a cutting error may occur during lamination or cutting, and an error may occur in the inclined side wall itself.

  Due to the influence of the errors as described above, a very large error may occur in the tilt angle of the film formed inside the finally manufactured prism. Accordingly, since it is impossible to ensure high accuracy of angular accuracy, it is extremely difficult to form the dielectric multilayer film on the prism with high angular accuracy in the invention of Patent Document 1.

  Accordingly, an object of the present invention is to provide a prism manufacturing method for manufacturing a prism having high angular accuracy.

  The prism manufacturing method of the present invention is a prism manufacturing method for manufacturing a prism in which a dielectric multilayer film is formed at a predetermined angle, and includes a large substrate that is a flat substrate, a large substrate, a width dimension, and A flat plate double-side polishing step for polishing flat surfaces and parallelism of both sides of the large substrate and the small substrate by polishing both surfaces of the small substrate having the same thickness and a depth dimension shorter than the large substrate, and the flat plate Dielectric multilayer film formation in which a dielectric multilayer film is formed on any two surfaces of the large substrate and the small substrate polished in a double-side polishing step to form a film formation surface and a non-film formation surface And a step of alternately bonding the large substrate and the small substrate so that the film-forming surface and the non-film-forming surface are bonded to each other in a stepwise manner with a predetermined interval in the width direction. And the back of the large substrate A substrate adhering step of obtaining a laminated glass body by laminating so that both ends in the vertical direction are exposed as reference planes, and the laminated glass body having a length equal to or longer than one side of the prism in a direction parallel to the stepwise inclination A laminated glass body cutting step to obtain a plurality of multiple glass bodies by cutting at intervals, and the two cut surfaces cut in the laminated glass body cutting step among the multiple glass bodies are double-side polished. A multiple glass body double-side polishing step for obtaining flatness and parallelism of two cut surfaces, and cutting the multiple glass body in a direction perpendicular to the polishing surface at intervals equal to or longer than one side of the prism. A multiple glass body cutting step for obtaining a plurality of strip glass bodies, and a first step of polishing the cut surface cut in the multiple glass body cutting step with reference to the reference surfaces formed at both ends of the strip glass body. 1 strip glass body polishing step, A strip glass body polished in the strip glass body polishing step, a second strip glass body polishing step that polishes the surface opposite to the surface polished in the strip glass body polishing step of 1; Strip glass body cutting to obtain a plurality of prisms by cutting at equal intervals in a direction perpendicular to the polishing surface polished in the multiple glass body double-side polishing step or the polishing surface polished in the strip glass body polishing step And a process.

  According to the prism manufacturing method of the present invention, when a large substrate and a small substrate are stacked, the large substrate is stacked such that both ends of the large substrate protrude from the small substrate in the depth direction. Since the large substrate and the small substrate have been subjected to surface polishing on both sides in advance, and flatness and parallelism are obtained, the polished surface is always exposed as a reference surface. And high angle precision can be taken out by grinding | polishing on the basis of a reference plane.

  Here, surface polishing is performed on both sides of the large substrate and the small substrate, but after that, a dielectric multilayer film is formed on both surfaces of the large substrate, and a dielectric multilayer film is not formed on both surfaces of the small substrate. . In this case, since the dielectric multilayer film is always formed on the exposed reference surface (the surface from which the large substrate protrudes), polishing is performed with the surface on which the dielectric multilayer film is formed as a reference. be able to. Therefore, it is possible to manufacture a prism having extremely high angle accuracy with respect to the surface on which the dielectric multilayer film is formed.

  In addition, the present invention can be applied to a case where a dielectric multilayer film is formed on both surfaces of a small substrate, not both surfaces of the large substrate, of both surfaces of a large surface-polished substrate and a small substrate. At this time, since the dielectric multilayer film is not formed on the large substrate, the dielectric multilayer film is not always formed on the exposed reference surface. Therefore, polishing is performed using the surface on which the dielectric multilayer film is not formed as a reference surface. In this case, the surface on which the dielectric multilayer film of the finally manufactured prism is formed is referred to as the reference surface. It becomes an opposing surface through an adhesive. For this reason, since it is necessary to manage the thickness of the adhesive with high accuracy, the angle accuracy is slightly reduced as compared with the case where the surface on which the above-described dielectric multilayer film is formed is used as the reference surface. There is also a case. However, even if the surface on which the dielectric multilayer film is formed is not used as a reference surface, polishing with reference to a reference surface having high accuracy flatness and parallelism remains the same. Even in this case, a prism having high angular accuracy can be manufactured.

  The present invention can also be applied to a large substrate and a substrate in which a dielectric multilayer film is formed on one surface of a small substrate. At this time, a dielectric multilayer film is formed on one surface of the exposed reference surface, but a dielectric layer film is not formed on the opposite surface. Therefore, the strip glass body having the reference surface on which the dielectric multilayer film is formed and the strip glass body having the reference surface on which the dielectric multilayer film is not formed are generated at a ratio of half. However, the angle accuracy of the surface on which the dielectric multilayer film is not formed may be slightly reduced, but since there is no change in polishing using the double-side polished surface as a reference surface, it has high angle accuracy. Can be manufactured.

  In this case, the angular accuracy may be slightly varied. For this reason, a dielectric multilayer film is formed on the one side surface of the large substrate and the small substrate, respectively, but the entire surface is formed on the one side surface of the small substrate. A dielectric multilayer film is formed on one side surface of the large substrate in the same region as the small substrate (the same region as the region bonded to the small substrate among the large substrate regions when the laminated glass body is configured). Form a film. For this reason, since the surface on which the dielectric multilayer film is not always formed becomes the reference surface, the above-described variation can be eliminated.

  The prism manufacturing method of the present invention can manufacture a prism having high angular accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the flowchart of FIG. FIG. 2 shows the prism 10 finally manufactured. The prism 10 of the present embodiment is a cube-type optical element having a side length of PL, and the dielectric multilayer film 3 is formed at an angle of 45 ° with respect to the optical axis. Here, in the present embodiment, the length of the diagonal line of each surface of the prism 10 (the long side of the surface on which the dielectric multilayer film 3 is formed) is the length PD of the diagonal line of the prism 10 (= PL × √2). ). Further, it is assumed that an antireflection film having an antireflection function is formed on each surface of the prism 10.

  First, as shown in FIG. 3, a plurality of two types of flat substrates (substrates such as glass substrates) having different shapes are prepared. FIG. 3A shows a large substrate 1 having a long side (width) of LX1, a short side (depth) of LY1, and a thickness of LZ1. FIG. 3B illustrates a small substrate 2 having a length of LX1, a depth of LY2 (LY2 <LY1), and a thickness of LZ1. Since the prism 10 to be finally produced is generated by laminating and cutting the large substrate 1 and the small substrate 2, the width (LX1), depth (LY1), thickness (LZ1), and The width (LX1), depth (LY2), and thickness (LZ1) of the small substrate 2 are all longer than (1 / √2) times the length PL of one side of the prism 10.

  As an initial process, both the surfaces of the prepared plural large substrates 1 and small substrates 2 are polished by lapping or the like (step S1). By this surface polishing, both the large substrate 1 and the small substrate 2 can have high flatness and parallelism. Then, the dielectric multilayer film 3 is formed on both surfaces of the large substrate 1 (step S2). At this time, in this embodiment, as shown in FIGS. 3A and 3B, both surfaces on which the dielectric multilayer film 3 of the large substrate 1 is formed are defined as film formation surfaces C, and the small substrate 2 is formed. Are defined as non-film-forming surfaces N.

  Next, a plurality of large substrates 1 and small substrates 2 are alternately stacked to obtain a laminated glass body 4 (step S3). In the laminated glass body 4, the large substrate 1 and the small substrate 2 are bonded to each other with an adhesive material so that the film formation surface C and the non-film formation surface N of each substrate are bonded as shown in FIG. 4. Laminate together. FIGS. 5A and 5B are a front view and a side view of FIG. 4, but the large substrate 1 and the small substrate 2 are stacked so as to be stepped with a predetermined interval in the width direction. In the depth direction, the large substrate 1 is laminated so that both ends protrude from the small substrate 2. 4, 5A and 5B show a laminated glass body 4 in which three large substrates 1 and two small substrates 2 are laminated. Of course, they are laminated. The number of substrates can be arbitrary. As shown in FIG. 5A, the large substrate 1 and the small substrate 2 are stacked in the width direction with the same interval as the thickness LZ1 of each substrate. Therefore, the stepwise inclination angle of the laminated glass body 4 forms an angle of 45 °. As is clear from FIGS. 4 and 5B, both ends of the large substrate 1 protrude more equally than the small substrate 2 (that is, as shown in FIG. 5B, “1 / 2 × (LY1−LY2) ”protrudes equally at both ends), and the protruding portion of the film formation surface C is exposed. Here, in the present embodiment, the exposed portion of the film formation surface C is defined as the reference surface B (as shown in FIG. 5B), the reference surface B is formed on both surfaces of the protruding portion of the large substrate 1. Defined as). Since the film-forming surface C has high flatness and parallelism and the reference surface B is a part of the film-forming surface C, the reference surface B also has high flatness and parallelism. . As will be apparent from the subsequent steps, by performing polishing with reference plane B as a reference, prism 10 in which dielectric multilayer film 3 is formed with extremely high angular accuracy (45 °) can be obtained. This will be described later.

  Then, the laminated glass body 4 is cut with a wire saw or the like at predetermined intervals along a broken line in FIG. 4 in a direction parallel to the stepped inclination or at an angle of 45 ° with respect to the end face (step) S4). By this cutting, a plurality of multiple glass bodies 5 as shown in FIG. 6A can be obtained. The cutting interval of the laminated glass body 4 at this time is obtained by adding a polishing allowance α to the diagonal line PD of the prism 10, as shown in FIG. This will be described later.

  Here, as will become apparent in the subsequent process, when the multiple glass body 5 is generated in step S4, the cut surfaces 5A and 5B of the multiple glass body 5 (two when the laminated glass body 4 is cut) If the cut surfaces (shown as the upper and lower surfaces in FIG. 6A) have high flatness and parallelism, the cut surfaces 5A and 5B constitute one surface of the prism 10 and its opposite surface. To do. However, the flatness of the cut surfaces 5A and 5B of the multiple glass body 5 after being cut in step S4 is not guaranteed. Therefore, the cut surfaces 5A and 5B of the multiple glass body 5 are polished to form the polished surfaces 5C and 5D as shown in FIG. 6B (step S5). By this polishing, the polished surfaces 5C and 5D can have high flatness and parallelism, and can constitute one surface of the prism 10 and the opposite surface, respectively. At this time, the multiple glass body 5 is polished so that the distance between the polished surfaces 5C and 5D of the multiple glass body 5 after polishing becomes the length PL of one side of the prism 10. Thereby, the two surfaces of the prism 10 can be strictly configured.

  By the way, the multiple glass body 5 is thinned (the distance between the polished surfaces 5C and 5D) by the polishing in step S5. Therefore, the cutting of the laminated glass body 4 in step S4 is performed with a cutting interval having a margin in advance in anticipation of the polishing allowance by polishing. Specifically, the laminated glass body 4 is cut at an interval obtained by adding the polishing allowance α to the length PD of the diagonal line of the prism 10, so that the polishing allowance is polished to obtain the flatness of the multiple glass bodies 5. Put out.

  In step S4, the cutting of the laminated glass body 4 is not performed at the interval obtained by adding the polishing allowance to the length PL of one side of the prism 10, but at the interval obtained by adding the polishing allowance to the diagonal length PD of the prism 10. The reason for this is that the length of the short side of the end face of the multiple glass body 5 corresponds to the diagonal length PD of the prism 10.

  The end surfaces 5E and 5F of the multiple glass body 5 after polishing shown in FIG. 6B are made up of a part of the uppermost substrate and the lowermost large substrate 1 or the small substrate 2 of the laminated glass body 4. is there. Since the large substrate 1 and the small substrate 2 constituting the laminated glass body 4 have high precision flatness and parallelism in step S1, the end surfaces 5E and 5F of the multiple glass body 5 may be used as a reference. it can. Therefore, by polishing the cut surfaces 5A and 5B with reference to the end surfaces 5E and 5F, the angle formed by the polishing surfaces 5C and 5D and the film formation surface C on which the dielectric multilayer film 3 is formed is 45 °. It can be formed with high angular accuracy.

  Next, an antireflection film is formed on the polished surfaces 5C and 5D of the polished multiple glass body 5 (step S6). As described above, the polished surfaces 5C and 5D of the multiple glass body 5 form one surface of the prism 10, and an antireflection film is formed at this point. Since a plurality of prisms 10 are generated from the multiple glass body 5, if an antireflection film is formed in advance, the antireflection films of the plurality of prisms 10 are formed at a time.

  Then, the multiple glass body 5 on which the antireflection film is formed is cut at a predetermined interval in a direction perpendicular to the polishing surfaces 5C and 5D, as indicated by a broken line in FIG. 6B (step S7). . By this cutting, a plurality of strip glass bodies 6 shown in FIG. 7A are generated.

  Here, when the multiple glass body 5 is cut, similarly to when the laminated glass body 4 is cut, the cut surfaces 6A and 6B (two cut surfaces when the multiple glass body 5 is cut: FIG. 7 ( In a), the flatness and parallelism of the side surface and the opposite surface are not guaranteed. The cut surfaces 6A and 6B constitute one surface of the prism 10 and its opposite surface if high flatness and parallelism are guaranteed. However, when the multiple glass body 5 is cut, flatness and parallelism are not guaranteed. Therefore, in order to polish the cut surfaces 6A and 6B to obtain the flatness and parallelism of both surfaces, the strip glass body 6 must be generated in consideration of the polishing allowance. Accordingly, when the multiple glass body 5 is cut, the cutting is performed at intervals obtained by adding the polishing allowance β to the length PL of one side of the prism 10. However, since the multiple glass bodies 5 in step S7 are cut in a direction parallel to the surface of the prism 10, the polishing allowance is added in addition to the length PL of one side of the prism 10 instead of the diagonal length PD of the prism 10. Cutting is performed with an interval that secures the amount of β.

  By the way, it is necessary to polish the cut surfaces 6A and 6B to obtain the flatness and parallelism of both surfaces after polishing. At this time, the both surfaces after polishing have a strictly 45 ° angle with respect to the film formation surface C. It is necessary to polish as much as possible. Therefore, polishing is performed using the reference plane B exposed at both ends of the strip glass body 6 as a reference. Since the reference surface B is a part of the film formation surface C, and the film formation surface C has high flatness and parallelism, if polishing is performed with reference to the reference surface B, the surface after polishing is formed as a film. An angle of 45 ° with the plane C can be formed strictly.

  First, as shown in FIG. 7B, the cut surface 6A of the strip glass body 6 is polished to obtain a polished surface 6C (step S8: first strip glass body polishing step). An example of a jig used when performing this polishing is shown in FIG. As shown in FIG. 8A, the jig 7 is provided with side wall portions 7S on both sides, and on each side wall portion 7S, placement portions 7P for placing both ends of the strip glass body 6 are placed. A plurality of are formed. A notch is formed in the mounting portion 7P, and a protrusion P of the strip glass body 6 (a portion where the reference plane B is exposed at both ends of the strip glass body 6) is held in the notch. The The cutout portion of the mounting portion 7P is composed of a vertical surface 7PA and a slope 7PB, and the angle between the slope 7PB and the bottom surface 7B of the jig 7 is strictly 45 °. The angle between the vertical surface 7PA and the inclined surface 7PB is also strictly 45 °. The cutout portion of the mounting portion 7P has a right isosceles triangular shape, and the height of the vertical surface 7PA is smaller than the length PL of one side of the prism 10. Further, the shape of the mounting portion 7P of the jig 7 is assumed to hold the angle with high accuracy, and the distance between the side wall portions 7S provided on both sides of the jig 7 is the depth of the small substrate 2. It is assumed that it is substantially the same as the dimension LY2 (substantially longer than the depth dimension LY2 so that the strip glass body 6 can be placed). As shown in FIG. 8B, the placing portion 7P is formed with a relief groove 7N to protect the edge of the protruding portion P of the strip glass body 6 placed on the placing portion 7P. Has been.

  The protruding portion P of the strip glass body 6 is placed on the placing portion 7P. FIG. 8B is a cross-sectional view showing the strip glass body 6 placed so that the cut surface 6A is the upper surface. The polishing surface 5D is placed so as to be in contact with the vertical surface 7PA so that the reference surface B of the protruding portion P of the strip glass body 6 is in contact with the inclined surface 7PB of the placement portion 7P. The angle formed by the inclined surface 7PB of the mounting portion 7P and the bottom surface 7B of the jig 7 is guaranteed to be 45 ° with high accuracy, and the angle formed by the reference surface B of the strip glass body 6 and the polishing surface 5D is also 45. °. Therefore, the protruding portion P of the strip glass body 6 is strictly fitted into the placing portion 7P. On the other hand, since the interval between the cut surfaces 6A and 6B of the strip glass body 6 is formed slightly longer than the length PL of one side of the prism 10, the cut surface 6A slightly protrudes from the upper surface 7U of the side wall portion 7S. It becomes a state. Therefore, the cut surface 6A of the raised prism 10 is polished, but this polishing is performed until it becomes equal to the length PL of one side of the prism 10. At this time, by polishing to the position of the ridgeline of the reference plane B as a guide, the polishing can be performed until it becomes equal to the length PL of one side of the prism 10. Accordingly, as shown in FIG. 7 (b), the portion of the strip glass body 6 that is the large substrate 1 has a rectangular shape with a cross section of a right isosceles triangle (two sides sandwiching the right angle are the length of PL). Can be obtained.

  Next, the cut surface 6B is polished (second strip glass body polishing: step S9). At this point, the polished surfaces 5C, 5D, and 6C of the strip glass body 6 are finished with high angular accuracy with respect to the film-forming surface C. Therefore, the remaining cut surface 6B is polished with the polished surface 6C as a reference to form a polished surface 6D as shown in FIG. 7C. The polishing surfaces 5C, 5D, and 6C are all finished with high angular accuracy with respect to the film formation surface C, and thus are not limited to the polishing surface 6C, but any one surface, any two surfaces, or all surfaces. The polishing surface 6D may be formed with reference to. As described above, the strip glass body 6 can be finished with high angular accuracy so that all of the polished surfaces 5C, 5D, 6C, and 6D form one surface of the prism 10.

  Note that the jig 7 described above is merely an example, and the gist of the present invention is that polishing is performed with reference to the reference surface B which is a part of the film formation surface C. Therefore, the jig 7 is shown in FIG. It is not limited to that. Accordingly, any material can be applied as long as it can be polished with the reference surface B as a reference. And, when performing the polishing of the cut surface 6B, what has been polished with reference to the polishing surfaces 5C, 5D and 6C, for example, prepared a jig capable of polishing with reference to the reference surface B, It is also possible to polish the cut surface 6B with such a jig.

  Then, since the antireflection film is not yet formed on the polished surfaces 6C and 6D, the antireflection film is formed on both surfaces (step S10), and the polishing is performed as shown by the broken line in FIG. 7C. Cutting is performed at equal intervals in a direction perpendicular to the surfaces 5C, 5D, 6C, and 6D (step S11). Cutting is performed so that the cutting interval at this time is equal to the length PL of one side of the prism 10. Thereby, it is possible to obtain the prism 10 having a high angular accuracy in which the dielectric multilayer film 3 is formed with an angle of 45 ° and having a side length PL as shown in FIG.

  As described above, according to the present invention, a large substrate and a small substrate, which are two types of substrates having the same width and thickness and different depth dimensions, are prepared, and a dielectric multilayer film is formed on one surface, respectively. Then, a plurality of large substrates and small substrates are alternately stacked. At this time, by laminating so that both ends of the large substrate protrude from the small substrate in the depth direction, a part of the surface on which the dielectric multilayer film is formed is always exposed as a reference surface. By performing polishing with reference to this reference surface, high angular accuracy can be obtained.

  Since the prism 10 of the above-described embodiment has a cubic shape and the surface on which the dielectric multilayer film 3 is formed is 45 °, the large substrate 1 and the small substrate 2 are described. Are joined at the same interval as the substrate thickness LZ1 in the width direction. That is, by shifting LZ1 in the width direction, the stepwise angle forms 45 °. However, if the interval other than LZ1 is shifted in the width direction, the stepwise angle is formed at an angle different from 45 °. In step S4, the laminated glass body 4 is cut in a direction parallel to the stepped inclination. If the stepped angle is formed at an angle different from 45 °, the prism 10 to be finally manufactured is formed. The surface on which the formed dielectric multilayer film 3 is formed can be at an angle different from 45 °. Further, the shape of the prism 10 can be different from the cube. Even at this time, although the angle is different from 45 °, it is possible to manufacture the one in which the dielectric multilayer film 3 is formed on the prism 10 with high angular accuracy.

  In the present invention, the optical pickup device has been described as an example. However, the present invention is not limited to this, and any configuration may be used as long as a dielectric multilayer film is formed on a cube-type prism at a predetermined angle. Can be applied to For example, the present invention can also be applied to a dichroic prism as an optical component constituting a liquid crystal projector that performs color separation and color synthesis. As the dichroic prism, a cube-shaped prism is used, and a dichroic film that separates reflection and transmission according to the wavelength of incident light is formed at an angle of 45 ° with respect to the optical path. Therefore, the present invention can be applied to such a dichroic prism.

It is a flowchart which shows the flow of a process of this invention. It is a perspective view of a prism. It is a perspective view of a large substrate and a small substrate. It is a perspective view of a laminated glass body It is the front view and side view of a laminated glass body It is a perspective view of a multiple glass body It is a perspective view of a strip glass body It is the perspective view and enlarged view of a jig | tool.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Large substrate 2 Small substrate 3 Dielectric multilayer film 4 Laminated glass body 5 Multiple glass body 6 Strip glass body 7 Jig B Reference plane C Deposition surface N Non-deposition surface

Claims (5)

A prism manufacturing method for manufacturing a prism in which a dielectric multilayer film is formed at a predetermined angle,
Polishing both sides of the large substrate, which is a flat substrate, and a small substrate having the same width and thickness as the large substrate and having a depth dimension shorter than the large substrate, the large substrate and the small substrate A flat plate double-side polishing process that produces flatness and parallelism on both sides,
Dielectric multilayer film in which a dielectric multilayer film is formed on any two surfaces of the large substrate and the small substrate polished in the flat plate double-side polishing step to form a film formation surface and a non-film formation surface A film forming process;
A step of alternately bonding the large substrate and the small substrate so that the film-forming surface and the non-film-forming surface are bonded to each other so as to be stepped with a predetermined interval in the width direction And a substrate bonding step of obtaining a laminated glass body by laminating so that both ends in the depth direction of the large substrate are exposed as reference surfaces;
A laminated glass body cutting step of obtaining a plurality of multiple glass bodies by cutting the laminated glass body at intervals equal to or longer than the length of one side of the prism in a direction parallel to the stepwise inclination,
Among the multiple glass bodies, the two cut surfaces cut in the laminated glass body cutting step are double-side polished, and the multiple glass body double-side polishing step for obtaining the flatness and parallelism of the two cut surfaces;
A multiple glass body cutting step for obtaining a plurality of strip glass bodies by cutting the multiple glass bodies in a direction perpendicular to the polishing surface at intervals equal to or longer than one side of the prism;
A first strip glass body polishing step for polishing a cut surface cut in the multiple glass body cutting step with reference to the reference surfaces formed at both ends of the strip glass body;
Based on the surface polished in the first strip glass body polishing step, a second strip glass body polishing step for polishing the surface opposite to this surface;
The strip glass body polished in the strip glass body polishing step is in a direction perpendicular to the polishing surface polished in the multiple glass body double-side polishing step or the polishing surface polished in the strip glass body polishing step. A prism glass body cutting step for obtaining a plurality of prisms by cutting at equal intervals.   2. The method of manufacturing a prism according to claim 1, wherein, in the substrate bonding step, the large substrate and the small substrate are shifted by a thickness of the substrate in the width direction so that the step shape is 45 degrees.   In the first strip glass body polishing step, both ends of the strip glass body are attached to a jig having a vertical surface having a height equal to the length of one side of the prism and a slope having an angle of 45 ° with the vertical surface. The method for manufacturing a prism according to claim 1, wherein the prism glass body is supported and the cut surface cut in the multiple glass body cutting step is polished to the height of the vertical surface.   2. The method for manufacturing a prism according to claim 1, wherein the second strip glass body polishing step polishes a surface that has not been polished in the first strip glass body polishing step on the basis of the reference surface. . In the prism manufacturing method, after the multiple glass body polishing step, an antireflection film is formed on the two polished surfaces polished in the multiple glass body polishing step,
2. The prism according to claim 1, wherein after the second strip glass body polishing step, the antireflection film is formed on the polished surfaces polished in the first and second strip glass body polishing steps. Manufacturing method.

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