JP2008139731A - Method for manufacturing right-angled triangular prism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a right-angled triangular prism excellent in dimensional accuracy. <P>SOLUTION: The method includes a process for laying a plurality of rectangular flat plates of glass one on top of each other and laying the rectangular flat plates of glass one upon another in a staircase pattern, by sequentially shifting the planar direction positions of the flat plates of glass so that the angle made by the plane ranging over the edges of the respective flat plates of glass and the plate face of the flat plates of glass becomes an inclination angle of 45 degrees; a process for cutting a first layered body into a plurality of layered cut bodies; a process for mirror-polishing the cut surface of each layered cut body; a process for forming a second layered body; a process for forming a third layered body; a process for mirror-polishing the cut surface and both of the edge faces of the third layered body; a process for dividing the third layered body into a plurality of right-angled triangular poles; and a process for cutting the right-angled triangular poles into individual pieces of right-angled triangular prisms. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a prism, and more particularly to a method for manufacturing a right triangle prism having excellent dimensional accuracy.

In an optical pickup device that reproduces information from or records information on an optical recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc), a prism is used as an optical device.
A number of examples are disclosed in patent documents and the like regarding the method of manufacturing an optical device as described above. For example, Patent Document 1 discloses a prism and a manufacturing method thereof.

FIG. 6 is a diagram showing the configuration of the prism disclosed in Patent Document 1. In FIG. FIG. 7 is a process diagram showing a prism manufacturing method disclosed in Patent Document 1.
The prism 20 shown in FIG. 6 is a right triangle prism made of a transparent optical glass such as BK-7 and having a right isosceles triangle shape.
The cross-section where the light-receiving surfaces 21a, 21b, and 21c that receive light such as an optical signal are connected to each other includes substantially R-shaped corner portions 20d, 20e, and 20f, and the surface is a fire-making surface.

The manufacturing method of the prism 20 as shown in FIG. 6 is based on the process charts shown in FIGS. A glass base material 22 shown in FIG. 7 (a) is made of BK-7, which is a borosilicate optical glass, and has a surface 22a, 22b, 22c that is a light-receiving surface. The cross section of the glass base material 22 is a right isosceles triangle having the surface 22a as a hypotenuse, and the side lengths of the surfaces 22b and 22c are about 10 mm to 70 mm, respectively.
As shown in FIG. 7B, the apparatus for drawing and forming the glass base material 22 heats the glass base material 22 to a predetermined temperature by feeding means (not shown) having a gripping part for gripping the glass base material 22. A heating furnace 23, a tension means that has a pair of rollers 24a and 24b and stretches the lower part of the glass base material 22, and a cutting means 25 that cuts the stretched glass. This is an apparatus for forming a long body 26 as shown in FIG. The obtained long body 26 is cut into a predetermined length by a precision cutting device to obtain a prism 27 as shown in FIG.

Patent Document 2 discloses a method of manufacturing a beam splitter in which the inclined surfaces of two right triangular prisms are joined together.
8 and 9 are schematic views showing the steps of the beam splitter disclosed in Patent Document 2. FIG.
A glass flat plate 30 shown in FIG. 8A has a configuration in which a polarization separation film 32 is formed on one surface (upper surface) of a plate glass 31 and a matching film 33 is formed on the other surface (lower surface). A laminated body is formed using a plurality of the glass flat plates 30 thus configured. FIG. 8B shows a state in which the glass flat plate 30 is laminated using the jig 34 at an inclination angle of 45 degrees. The jig 34 includes a horizontal plate-like base 34a and an inclined side wall 34b fixed by being inclined 45 degrees from the base 34a. A glass plate 30 having a polarization separation film 32 on the upper surface and a matching film 33 on the lower surface is sequentially laminated on the base 34a. At this time, by aligning one end of the glass flat plate 30 along the inclined side wall 34b, a step-like laminate 35 in which each glass flat plate 30 is shifted by an equal distance in the plane direction is formed. That is, the laminated body 35 has a substantially parallelogram front shape. Here, the glass flat plates 30 are bonded to each other with a UV curable optical adhesive.
Next, the laminated body 35 integrated with the adhesive is removed from the jig 34, and as shown in FIG. 8 (c), along the inclination angle of 45 degrees indicated by the broken line 35a, a wire saw or the like is used. Then, the laminated divided body 36 as shown in FIG. 9A is obtained.

Next, as shown in FIG. 9B, the upper and lower surfaces (cut surfaces) 36a and 36b of the laminated divided body 36 are mirror-polished and a reflective film is coated on each surface. First, cut the acutely protruding portions at both ends of the laminated division 36 or laminate the laminated division 36 in an aligned state as shown in FIG. 9C to form a laminated body 37. It may be cut after being temporarily fixed. When the laminated body 37 is cut at a predetermined pitch using a wire saw or the like along the cut surface 37a orthogonal to the cut surface 36a, a beam splitter coupling body 38 shown in FIG. 9D is obtained. When the cut surface is mirror-polished and the beam splitter coupling body is cut at a predetermined pitch along the broken line 38a shown in FIG. 9D, a beam splitter 39 as shown in FIG. 9E is obtained. Become.
JP 2003-329817 A JP 2000-143264 A

However, when a prism is manufactured using the prism manufacturing method disclosed in Patent Document 1, the three edges of the right triangular prism are substantially R-shaped and become strong, but a right triangular prism having a desired accuracy, for example, a right angle There was a problem that accuracy and dimensional accuracy of each side could not be obtained. Further, although Patent Document 2 discloses a method for manufacturing a beam splitter in which inclined surfaces of a right triangular prism prism are joined together, there is a problem that a method for manufacturing a right triangular prism is not disclosed.
In view of the above problems, the present invention is to provide a method of manufacturing a right triangle prism having excellent dimensional accuracy.

In order to achieve the above object, a method for manufacturing a right triangular prism according to the present invention includes a method of laminating a plurality of rectangular flat plate optical members via a temporary fixing material, and a plane connecting edges of the flat plate optical members. A first laminated body forming step of sequentially laminating the plane direction positions of the flat optical member so that the angle between the flat optical member and the plate surface is 45 °, and forming the first laminated body; A first cutting step of cutting the first laminated body integrated in the step into a plurality of laminated divided bodies at a plurality of parallel cut surfaces having a predetermined pitch along an inclination angle of 45 °; The first mirror polishing step for mirror polishing the cut surface of each layered division formed in the process, and the alignment state so that the mirror surfaces of the plurality of layered divisions mirror-polished by the first mirror polishing step face each other Laminate with each other, and temporarily fix between each laminated division with temporary fixative A second laminated body forming step for forming the second laminated body, and a third laminated body for forming the third laminated body by cutting the second laminated body at a cut surface orthogonal to the cut surface in the first cutting step. Forming step, a second mirror polishing step of mirror-polishing the cut surface of the third laminate obtained by the third laminate formation step and both end surfaces thereof, and releasing the temporary fixing of the third laminate. A cutting step for dividing the right triangular prism into two, and a second cutting for cutting the right triangular prism obtained in the dividing step into individual pieces of a right triangular prism at a plurality of parallel cut surfaces having a predetermined pitch orthogonal to the length direction. And a process.
According to the present invention as described above, it is possible to manufacture a right triangular prism having excellent dimensional accuracy. For example, the right angle accuracy required for the right triangle prism is cut perpendicularly to the surface of the laminate and is subjected to a mirror polishing process, so that the required accuracy can be sufficiently satisfied. In addition, since the dimensional accuracy of the three surfaces of the right triangular prism is subjected to a mirror polishing finishing process including lapping finishing and polishing finishing, it can be configured with sufficient accuracy to satisfy the required specifications.

The method for manufacturing a right triangular prism according to the present invention further includes a multilayer film forming step of forming a predetermined multilayer film on each of two side faces sandwiching the right angle of the right triangular prism obtained in the dividing step, and in the second cutting step, The right triangular prism obtained from the multilayer film forming step is cut at a plurality of parallel cut surfaces having a predetermined pitch perpendicular to the length direction.
According to the present invention as described above, a right triangular prism having an optical multilayer film excellent in dimensional accuracy can be manufactured. For example, the right angle accuracy required for a right triangle prism having an optical multilayer film is cut perpendicularly to the surface of the laminate and undergoes a mirror polishing process, so that the required accuracy can be sufficiently satisfied. In addition, the dimensional accuracy of the three surfaces of the right triangular prism can be configured with sufficient accuracy to satisfy the required specifications because it undergoes a mirror polishing finishing process including lapping finishing and polishing finishing.

Hereinafter, an embodiment of a method for manufacturing a right triangle prism according to the present invention will be described in detail with reference to the drawings.
1 and 2 are process diagrams for explaining a method of manufacturing a right triangle prism according to the present embodiment.
In this case, as for the glass flat plate 1 which is a rectangular flat optical member shown in FIG. 1A, the upper and lower flat surfaces 1a and 1b are mirror-polished.
In this case, first, as a 1st laminated body formation process, a laminated body is formed using multiple glass flat plates 1 as mentioned above. FIG. 1B shows a state in which the glass flat plate 1 is laminated using the jig 2 at an inclination angle of 45 degrees. The jig 2 includes a horizontal plate-like base 2a and an inclined side wall 2b fixed by being inclined 45 degrees from the base 2a. The glass flat plate 1 is sequentially laminated on the base 2a, and one end of the glass flat plate 1 is aligned along the inclined side wall 2b. It is formed. That is, the angle formed by the plane connecting the edges of each glass flat plate 1 and the plate surface of each glass flat plate 1 is an inclination angle of 45 degrees, and the front shape is a laminated body having a substantially parallelogram. At this time, the glass plates 1 are bonded to each other with a temporary fixing agent. For example, shift wax or water-soluble adhesive is used as the first temporary fixing agent.

Next, as a first cutting step, the first laminated body 3 integrated with the temporary fixing agent is removed from the jig 2, and a wire saw is taken along a 45 ° inclination angle indicated by a broken line 3a in FIG. Etc. is used to cut a plurality of laminated sections 4 as shown in FIG. 1C.
Next, as a first mirror polishing step, the cut surface 3a of the obtained multilayer divided body 4 is mirror polished. Next, as a second laminated body forming step, the second laminated body 5 is formed by laminating in an aligned state so that the mirror surfaces of the laminated divided bodies 4 face each other as shown in FIG.
In addition, the part which protrudes in the acute angle shape of the both ends of the laminated division body 4 is cut | disconnected before performing a mirror surface process, or it cut | disconnects after temporarily fixing with a temporary fixing agent in a 2nd laminated body formation process. Also good.

Next, as a third laminated body forming step, the second laminated body 5 is cut (divided) using a wire saw or the like along the cut surface 5a orthogonal to the cut surface 3a, and the third laminate shown in FIG. The laminated body 6 is formed.
Next, as a second mirror polishing step, both main surfaces 6a and 6b of the third laminate 6 shown in FIG. 2A are mirror-polished. Thereafter, as a dividing step, the temporary fixing material of the third laminated body 6 shown in FIG. 2A is dissolved and removed to obtain a plurality of right triangular prisms 7 as shown in FIG. The two surfaces 7a and 7b sandwiching the right angle of the obtained right triangular prism 7 are mirror-polished in the previous step. Further, since the inclined surface 7c of the right triangular prism 7 is the main surface 1a, 1b of the glass flat plate 1, it has a mirror-polished surface.
Next, as a second cutting step, as shown in FIG. 2 (c), the right triangular prism 7 is perpendicular to the longitudinal direction 8 thereof, and the right triangular prism 7 is formed in a plurality of parallel cross sections (broken lines 9) with a predetermined pitch. When cut, a right triangular prism 10 shown in FIG. 2D can be obtained.

  If a right triangular prism is manufactured in this way, it is possible to manufacture a right triangular prism that is superior in dimensional accuracy as compared to the manufacturing method disclosed in the conventional Patent Document 1. For example, the right angle accuracy required for the right triangle prism is cut perpendicularly to the surface of the laminate and is subjected to a mirror polishing process, so that the required accuracy can be sufficiently satisfied. In addition, since the dimensional accuracy of the three surfaces of the right triangular prism is subjected to a mirror polishing finishing process including lapping finishing and polishing finishing, it can be configured with sufficient accuracy to satisfy the required specifications.

Next, a manufacturing method of a right triangular prism provided with an optical multilayer film will be described as another manufacturing method of the right triangular prism with reference to FIGS. In this case, the steps from FIG. 1A to FIG. 1D and FIG. 2A to FIG. 2B described in the method for manufacturing the right triangular prism are the same, and the description thereof is omitted.
As shown in FIG. 3, when the right triangular prism 11 having the multilayer optical films 11a and 11b formed on the two side surfaces sandwiching the right angle is manufactured, the steps up to FIG. A right triangular prism 12 as shown in FIG.
Then, optical multilayer films 13a and 13b as shown in FIG. 4B are formed on the surfaces 12a and 12b sandwiching the right angle of the right triangular prism 12 by means of vapor deposition or the like, and the right triangular prism 12 to which the multilayer film is attached is formed. obtain. Next, as shown in FIG. 4C, the right triangular prism 12 provided with the multilayer film is cut at a plurality of parallel sections 14 having a predetermined pitch perpendicular to the length direction as shown in FIG. Individual right triangular prisms 11 can be obtained.
If a right triangular prism having an optical multilayer film is manufactured in this manner, a right triangular prism having a multilayer optical film having excellent dimensional accuracy can be manufactured.

FIG. 5A is an example of a right triangle prism having the optical multilayer film manufactured as described above. The right-angled triangular prism 15 shown in FIG. 5 is an optical path changing prism, and antireflection films 15a and 15b are formed on side surfaces sandwiching the right angle. When light 16 enters the optical path changing prism 15 from above in the figure, it is totally reflected by the inclined surface 15 c to become light 17 whose optical path has been converted by 90 °, and is emitted from the side surface of the optical path changing prism 15. As described above, the optical path changing prism 15 shown in FIG. 5 has a function of converting the optical path of light by 90 °.
FIG. 5B shows an optical pickup device configured using a right triangular prism having an optical multilayer film manufactured as described above.
The optical pickup device shown in FIG. 5B includes laser diodes 20a and 20b, polarizing beam splitters 21a and 21b, a right triangular prism 22 with an optical multilayer film according to the present invention, a wave plate 23, and a condenser lens 24. And photodetectors 26a and 26b. As the laser diode 20a, for example, a laser diode for a CD having a wavelength of 780 nm or a DVD having a wavelength of 650 nm may be used, and an optical pickup device using a laser diode having a blue wavelength band having a wavelength of 405 nm as the laser diode 20b may be used. On the surfaces of the side faces 22a and 22b sandwiching the right angle of the right triangular prism 22, an optical multilayer film having optical characteristics for reflecting laser light in the wavelength band of 780 nm or 650 nm, and optical characteristics for reflecting laser light in the wavelength band of 405 nm are provided. Each optical multilayer film is formed. As described above, when the right triangular prism with an optical multilayer film is used in the optical pickup device, the optical path emitted from the laser diode can be converted by 90 ° and incident on the disk 25. Therefore, the optical pickup device can be downsized. it can.
The optical multilayer film formed on the right triangular prism is not limited to the optical multilayer film described above. For example, a polarization separation film or a reflective film that reflects light in a desired wavelength band can be formed on the inclined surface of the right triangular prism.
In the embodiments of the manufacturing method of the right triangle prism according to the present invention, glass is used for explanation. However, the present invention is not limited to this and can be widely applied to optical members such as quartz.

The figure which showed the manufacturing process of the right triangle prism which concerns on this embodiment. The figure which showed the manufacturing process of the right triangle prism which concerns on this embodiment. It is the figure which showed the right triangle prism which has a multilayer optical film. The figure which showed the manufacturing process of the right triangle prism shown in FIG. The figure which showed an example of the right triangle prism. The figure which showed the structure of the conventional right-angled isosceles triangular prism. Process drawing explaining the manufacturing method of the prism shown in FIG. The figure which shows the process of the manufacturing method of the conventional beam splitter. The figure which shows the process of the manufacturing method of the conventional beam splitter.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Glass flat plate, 2 ... Jig, 3 ... 1st laminated body, 3a, 5a, 9, 14 ... Cut surface, 4 ... Laminated division body, 5 ... 2nd laminated body, 6 ... 3rd laminated body, 7 ... Right-angled triangular prism, 10, 11 ... Right-angled triangular prism, 11a, 11b, 13a, 13b ... Multilayer film, 15 ... Optical path changing prism

Claims (2)

A plurality of rectangular flat plate-shaped optical members are laminated via a temporary fixing material, and an angle formed by a plane connecting the edges of the flat plate-shaped optical members and the plate surface of the flat plate-shaped optical member is an inclination angle of 45 ° A first laminated body forming step of sequentially laminating the plane direction position of the flat optical member so as to be laminated stepwise;
A first cutting in which the first laminated body integrated in the first laminated body forming step is cut into a plurality of laminated divided bodies at a plurality of parallel cut surfaces having a predetermined pitch along the 45 ° inclination angle. Process,
A first mirror polishing step of mirror polishing the cut surface of each of the laminated divided bodies formed by the first cutting step;
The plurality of laminated division bodies mirror-polished in the first mirror polishing step are laminated in an aligned state so as to face each other, and each laminated division is temporarily fixed with a temporary fixing agent to form a second lamination. A second laminate forming step for forming a body;
A third laminated body forming step of forming the third laminated body by cutting the second laminated body at a cut surface orthogonal to the cut surface in the first cutting step;
A second mirror polishing step of mirror polishing the cut surface of the third laminate obtained by the third laminate forming step and both end faces thereof;
A dividing step of releasing the temporary fixing of the third laminate and dividing into a plurality of right triangular prisms;
And a second cutting step of cutting the right triangular prism obtained in the dividing step into pieces of a right triangular prism at a plurality of parallel cut surfaces having a predetermined pitch orthogonal to the length direction. A manufacturing method of a right triangle prism. A multilayer film forming step of forming a predetermined multilayer film on each of two side surfaces sandwiching the right angle of the right triangular prism obtained in the dividing step;
2. The second cutting step, wherein the right triangular prism obtained from the multilayer film forming step is cut at a plurality of parallel cut surfaces having a predetermined pitch perpendicular to the length direction. Manufacturing method of right angle triangular prism.

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