JP2008145482A - Manufacturing method of right-angled triangular prism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a right-angled triangular prism which is low in cost and is excellent in dimensional accuracy. <P>SOLUTION: The manufacturing method of the right-angled triangular prism comprises a process for forming a plate-shaped optical member by forming optical multilayered films respectively on upper and lower surfaces of a rectangular glass plate, a process for laminating plate-shaped optical members by using a temporarily fastening material, a process for cutting a laminated body by orthogonally intersecting its main surface, a process for carrying out mirror polishing of a cut surface of the cut laminated body, a process for forming optical multilayered films on respective flanks of the cut laminated body subjected to mirror polishing, a process for obtaining a regular square pole having a regular square end face by dissolving off the temporarily fastening material of the cut laminated body, a process for attaching the regular square pole to a cutting jig having a triangular groove, cutting the regular square pole along its diagonal line and then exfoliating the cut pole from the cutting jig, a process for attaching a right-angled triangular pole to a polishing jig having the triangular groove, carrying out mirror polishing of its slope and then exfoliating the polished pole from the polishing jig and a process for cutting the right-angled triangular pole the slope of which is subjected to mirror polishing at cutting surfaces orthogonally intersecting in a longitudinal direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a right triangle prism, and more particularly to a method for manufacturing a right triangle prism having an optical multilayer film.

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 30 shown in FIG. 6 is a right triangle prism made of transparent optical glass such as BK-7 and having a right isosceles triangle shape.
The cross-section where the light-receiving surfaces 31a, 31b, 31c to which light such as an optical signal hits is composed of substantially R-shaped corner portions 30d, 30e, 30f, and the surface thereof is a fire-making surface.

  The manufacturing method of the prism 30 as shown in FIG. 6 is based on the process charts shown in FIGS. The glass base material 32 shown to Fig.7 (a) consists of BK-7 which is a borosilicate type | system | group optical glass, and the shape has the surface 32a, 32b, 32c used as an optical surface. The cross section of the glass base material 32 is a right isosceles triangle having the surface 32a as an oblique side, and the side lengths of the surfaces 32b and 32c are about 10 mm to 70 mm, respectively.

  As shown in FIG. 7 (b), the apparatus for drawing and molding the glass base material 32 heats the glass base material 32 to a predetermined temperature by feeding means (not shown) having a gripping part for gripping the glass base material 32. A heating furnace 33, a pair of rollers 34a and 34b, a tension means for stretching and forming the lower part of the glass base material 32, and a cutting means 35 for cutting the stretched glass. This stretch molding device is a device that has a desired range of dimensions approximately similar to the base material 32 and is molded into a long body 36 as shown in FIG. The obtained long body 36 is cut into a predetermined length by a precision cutting device to obtain a prism as shown in FIG.

  Patent Document 2 discloses a method of manufacturing a beam splitter in which inclined surfaces of two right triangular prisms are joined together. In Patent Document 2, a polarization separation film is formed on the upper surface of a plate glass, and a matching film is formed on the lower surface. A plurality of glass flat plates having the same configuration are used to form a laminated body with an inclination angle of 45 degrees. The laminated body is cut at a predetermined pitch using a wire saw or the like along an inclination angle of 45 degrees to form a laminated divided body. The cut surface of the laminated divided body is mirror-polished and a reflective film is coated on each surface. A laminated body is formed by stacking the laminated division bodies in an aligned state. When the laminated body is cut at a predetermined pitch using a wire saw or the like along a cutting plane orthogonal to the cutting plane, a coupled body of beam splitters is obtained. And if a beam splitter coupling body is cut | disconnected by a predetermined pitch, a beam splitter will be obtained.

Patent Document 3 discloses another method of manufacturing a beam splitter. In Patent Document 3, a polarization separation film is formed on one surface of a glass plate whose both surfaces are mirror-polished, and a UV curable adhesive is further applied. When a similar glass plate is laminated on a glass plate coated with a UV curable adhesive, a plate laminate in which an intermediate member (polarized light separation film and UV curable adhesive) is sandwiched is formed. When the plate laminate is cut along a side surface at a predetermined interval, an elongated regular quadrangular prism having a square end surface is formed. Next, when the four corners of the square prism are polished along a diagonal line using a polishing jig, the inclined surfaces of the two right triangular prisms are joined together, and a polarizing film is sandwiched between the joined surfaces to be integrated It is disclosed that a splitter is obtained.
JP 2003-329817 A JP 2000-143264 A JP 2003-137615 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 cube-shaped beam splitter, it does not disclose a right-triangular prism having an optical multilayer film on a side surface sandwiching a right angle. Patent Document 3 discloses a method of manufacturing a beam splitter in which the inclined surfaces of two right-angled triangular prisms are joined together and a polarizing film is sandwiched between the joined surfaces. Although the manufacturing method can be applied to form a right triangular prism, there has been a problem that the polishing process (machining process) takes a great number of steps and costs increase.
In view of the above problems, the present invention is to provide a method for manufacturing a right triangular prism that is low in cost and excellent in dimensional accuracy.

In order to achieve the above object, the present invention provides a method for manufacturing a right-angled triangular prism having first and second optical multilayer films on side surfaces sandwiching a right angle, wherein the first surface is formed on one side of a rectangular flat optical member. 1st optical multilayer film formation process which forms 1 optical multilayer film, and forms the 2nd optical multilayer film in the other side, and lamination which laminates a plurality of tabular optical members via the 1st temporary fixative Cut by a first cutting step, a first cutting step of cutting at a plurality of cut surfaces having a predetermined pitch orthogonal to a main surface of the laminate formed in the laminate forming step, and a first cutting step. A mirror polishing step of mirror-polishing the cut surface of the laminated divided body, a first optical multilayer film on one side surface of the laminated divided body mirror-polished by the mirror polishing step, and a second optical multilayer film on the other side surface A second optical multilayer film forming step, and a second optical multilayer film shape A peeling step of peeling off the first temporary fixing agent of the multilayer divided body having the optical multilayer film formed on the side surface in the process to form a square prism having a square end face; and the square pillar at the tip of the triangular groove A first mounting step of mounting on a cutting jig having a rectangular groove via a second temporary fixing agent, and cutting a regular square column mounted on the cutting jig along a diagonal line of the regular square column; A cutting and peeling step for further peeling, a second mounting step for mounting the right triangular prism obtained by the cutting and peeling step on a polishing jig having a triangular groove via a second temporary fixing agent, and a second mounting step Mirror-polishing the slopes of a plurality of right-angled triangular prisms attached to a polishing jig and peeling them off from the polishing jigs, and the right-angled triangular prisms whose slopes are mirror-polished in the mirror polishing / peeling process in the longitudinal direction A second one that cuts at a plurality of cutting surfaces orthogonal to each other at a predetermined pitch Characterized in that it comprises a cutting step.
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, since the right angle accuracy required for the right triangle prism is fixed to the triangular groove of the cutting jig and cut, 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 by selecting a predetermined rectangular flat plate optical member and appropriately cutting the laminate. Since the polishing process does not require a large number of steps, the cost does not increase.

The present invention also relates to a method of manufacturing a right triangular prism having first and second optical multilayer films on side surfaces sandwiching a right angle, wherein the first optical multilayer film is provided on one surface of a rectangular flat optical member. A first optical multilayer film forming step of forming a second optical multilayer film on the other surface, a multilayer body forming step of laminating a plurality of flat optical members via a first temporary fixing agent, and laminating A first cutting step of cutting at a plurality of cut surfaces having a predetermined pitch orthogonal to a main surface of the laminated body formed in the body forming step, and cutting of the multilayer divided body cut by the first cutting step Mirror polishing process for mirror-polishing the surface, and peeling off the first temporary fixing agent of the layered product that has been mirror-polished by the mirror polishing process to form the first and second optical multilayer films on the two opposing side surfaces By the peeling process and the peeling process in which the end face formed is a square square prism The optical multilayer film was formed in the second optical multilayer film forming step and the optical multilayer film forming step in which the first and second optical multilayer films were respectively formed on the two mirror-polished surfaces facing each other of the square prism A first mounting step of mounting a regular quadrangular prism on a cutting jig having a rectangular groove at the tip of a triangular groove via a second temporary fixing agent; and the regular quadrangular column mounted on the cutting jig A cutting and peeling step of cutting along the diagonal line of the cutting and peeling from the cutting jig, and a right triangular prism obtained by the cutting and peeling step is attached to the polishing jig having a triangular groove via the second temporary fixing agent. The mirror surface polishing / peeling process of mirror-polishing the slopes of a plurality of right-angled triangular prisms attached to the polishing jig in the mounting process 2 and the second mounting process, and the slopes in the mirror polishing / peeling process A right-angled triangular prism that is mirror-polished is perpendicular to the longitudinal direction. Characterized in that it comprises a second cutting step of cutting by a plurality of cut surfaces of constant pitch, the.
According to such a method for manufacturing a right triangular prism, it is possible to manufacture a right triangular prism having an optical multilayer film with excellent dimensional accuracy. For example, since the right angle accuracy required for the right triangle prism is fixed to the triangular groove of the cutting jig and cut, 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 by selecting a predetermined rectangular flat plate optical member and appropriately cutting the laminate. In addition, since the polishing process does not require a large number of steps, the cost does not increase.

Hereinafter, an embodiment of a manufacturing method of a right triangle prism according to the present invention will be described in detail with reference to the drawings.
1 to 4 are process schematic diagrams for explaining a method of manufacturing a right triangle prism according to the present invention.
In this case, first, as a first optical multilayer film forming step, the first optical multilayer film 3 is placed on the upper surface (one surface) of the rectangular glass flat plate 2 as shown in FIG. ), The second optical multilayer film 4 is formed to form the flat optical member 1.
Next, as shown in FIG. 1B, a flat plate-shaped optical member 1 in which the first optical multilayer film 3 is formed on the upper surface and the second optical multilayer film 4 is formed on the lower surface is not shown in the laminate formation process. A laminated body 5 is formed by laminating a plurality of layers via the first temporary fixing agent. At this time, a right angle treatment (not shown) is performed so that the plane connecting the end faces of the flat optical member 1 is perpendicular to the main surface of the flat optical member 1, that is, the front view of the laminate 5 is rectangular. Laminate using tools. For example, shift wax or water-soluble adhesive is used as the first temporary fixing agent.

Then, as a first cutting step, as shown in FIG. 1 (c), the laminate 5 is cut at a plurality of cut surfaces 5a having a predetermined pitch orthogonal to the main surface (laminated surface). The laminated division body 6 shown in (d) is formed, and then a mirror polishing process is performed on the cut surface 5a of the laminated division body 6 as a mirror polishing step.
Next, as a second optical multilayer film forming step, as shown in FIG. 2A, the first optical multilayer film 7a and the second optical film are respectively formed on the two side surfaces of the laminated divided body 6 which have been subjected to mirror polishing. A multilayer film 7b is formed. Thereafter, as the peeling step, the first temporary fixing agent of the layered divided body 7 is peeled off, so that the end surfaces as shown in FIG. Thus, a regular quadratic prism 8 in which 3, 7a and the second optical multilayer films 4, 7b are formed is obtained.

Next, as a first mounting step, as shown in FIG. 2 (c), a second temporary fixing agent is applied to a cutting jig 9 in which a regular square column 8 is formed with a rectangular groove 10b at the tip of a triangular groove 10a. As shown in FIG. 2D, the cutting and peeling process is performed by using a slicer or the like along the diagonal line of the regular quadratic prism 8 and peeling from the cutting jig 9 as shown in FIG. A right triangular prism 11 as shown in a) is obtained. Here, FIG. 2D shows a blade portion 51 of a slicer and an outer peripheral blade 51a attached to the blade portion 51 as an example. For example, a shift wax is used as the second temporary fixing agent.
A first optical multilayer film and a second optical multilayer film are formed on the surfaces 11a and 11b sandwiching the right angle of the right triangular prism 11 shown in FIG. In the example shown in FIG. 2B, an example in which the first optical multilayer films 3 and 7a (or the second optical multilayer films 4 and 7b) are arranged on the adjacent side surfaces is shown. The first optical multilayer film 3 and the second optical multilayer film 7b (or the second optical multilayer film 4 and the first optical multilayer film 7a) may be disposed, respectively. However, the first optical multilayer film 7a and the second optical multilayer film 7b are arranged on the side surfaces sandwiching the right angle of the triangular prism obtained by cutting the regular quadrangular prism 8 along its diagonal line. Just cut it.

Next, as a second mounting step, the right triangular prism 11 shown in FIG. 3A is attached to the groove 12a of the polishing jig 12 provided with a plurality of triangular grooves 12a as shown in FIG. 3B. Then, after fixing with the second temporary fixing agent, as the mirror polishing / peeling step, the inclined surface 11c of the right triangular prism 11 is mirror polished and the right triangular prism 11 is peeled from the polishing jig 12.
Thereafter, as a second cutting step, as shown in FIG. 3 (c), cutting is performed at a plurality of cutting surfaces 11a ′ having a predetermined pitch perpendicular to the longitudinal direction of the right triangular prism 11 ′. The right triangular prism 13 shown in FIG. That is, the first optical multilayer film 13a and the second optical multilayer film 13b are formed on the side surfaces sandwiching the right angle of the right-angle triangular prism 13, and the right-angle triangular prism 13 whose slope is mirror-polished is obtained. Can do.
If the right triangular prism 13 is manufactured in this way, a right triangular prism having an optical multilayer film with excellent dimensional accuracy can be manufactured. For example, since the right angle accuracy required for the right triangle prism 13 is fixed to the triangular groove of the cutting jig and cut, the required accuracy can be sufficiently satisfied. The dimensional accuracy of the three surfaces of the right triangular prism 13 can be configured with sufficient accuracy to satisfy the required specifications by selecting a predetermined rectangular glass flat plate and appropriately cutting the laminate. Further, the cost is not increased because the polishing process does not require a significant man-hour.

A second embodiment of the method for manufacturing a right triangular prism according to the present invention will be described.
In this case, the description up to FIG. 1 described in the manufacturing method of the right triangular prism is the same as the above description, and the description is omitted.
In this case, the cut surface 5a of the laminated divided body 6 shown in FIG. 1 (d) is mirror-polished, and then the temporary fixing material is dissolved and removed to obtain a regular square column 14 as shown in FIG. As shown in FIG. 4, the first and second optical multilayer films 3 and 4 are formed on the upper and lower surfaces of the regular square column 14, respectively, and the side surfaces 14a and 14b are mirror-polished. If the first and second optical multilayer films are formed on the side surfaces 14a and 14b, respectively, of which the regular square column 14 is mirror-polished, a regular square column similar to the regular square column 8 shown in FIG. 2B can be obtained. The subsequent processes are the same as the processes shown in FIGS. 2C, 2D and 3A to FIG. A right-angled triangular prism having a first optical multilayer film and a second optical multilayer film, whose slope is mirror-polished, can be manufactured.

  If the right triangular prism 13 is manufactured in this way, a right triangular prism having an optical multilayer film with excellent dimensional accuracy can be manufactured as described above. For example, since the right angle accuracy required for the right triangle prism is fixed and cut in the triangular groove of the cutting jig, the required accuracy can be sufficiently satisfied. Further, the dimensional accuracy of the three surfaces of the right triangular prism can be configured with sufficient accuracy to satisfy the required specifications by selecting a predetermined rectangular glass plate and appropriately cutting the laminate. In addition, since the polishing process does not require a large number of steps, the cost does not increase.

  FIG. 5A is an example of a right triangle prism having the optical multilayer film manufactured as described above. The right triangular prism 15 shown in FIG. 5A 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 is 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. 5A 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.

(A) thru | or (d) are the schematic process drawings which showed the manufacturing method of the right triangular prism prism which concerns on this invention. (A) thru | or (d) are the schematic process drawings which showed the manufacturing method of the right triangular prism prism which concerns on this invention. (A) thru | or (d) are the schematic process drawings which showed the manufacturing method of the right triangular prism prism which concerns on this invention. The perspective view which shows a regular square pole. FIG. 4A is a diagram illustrating an example of an optical path changing prism, and FIG. 4B is a diagram illustrating a configuration example of an optical pickup device. The figure which showed the structure of the conventional right-angled isosceles triangular prism. (A) thru | or (d) is process drawing explaining the manufacturing method of the prism shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Flat optical member, 2 ... Glass flat plate, 3, 13a ... 1st optical multilayer film, 4, 13b ... 2nd optical multilayer film, 5 ... Laminated body, 5a ... Cut surface, 6 ... Laminated division body, DESCRIPTION OF SYMBOLS 8 ... Regular square column, 9 ... Cutting jig, 10a ... Triangular groove, 12 ... Polishing jig, 13 ... Right triangle prism, 14 ... Regular square column, 15a, 15b ... Optical multilayer film, 51 ... Blade

Claims (2)

A method of manufacturing a right triangular prism having first and second optical multilayer films on side surfaces sandwiching a right angle, respectively,
A first optical multilayer film forming step of forming a first optical multilayer film on one surface of a rectangular flat optical member and forming a second optical multilayer film on the other surface;
A laminated body forming step of laminating the plurality of flat optical members via a first temporary fixing agent;
A first cutting step of cutting at a plurality of cut surfaces having a predetermined pitch perpendicular to the main surface of the laminate formed in the laminate formation step;
A mirror polishing step of mirror polishing the cut surface of the laminate divided body cut by the first cutting step;
A second optical multilayer film forming step of forming a first optical multilayer film on one side surface of the multilayer divided body mirror-polished by the mirror polishing step and a second optical multilayer film on the other side surface,
A peeling step of peeling off the first temporary fixing agent of the laminated divided body having the optical multilayer film formed on the side surface in the second optical multilayer film forming step to form a square prism having a square end surface;
A first mounting step of mounting the regular quadrangular column on a cutting jig having a rectangular groove at the tip of a triangular groove via a second temporary fixing agent;
A cutting and peeling step of cutting the regular square column mounted on the cutting jig along the diagonal of the regular square column and peeling from the cutting jig,
A second mounting step of mounting the right triangular prism obtained by the cutting and peeling step on a polishing jig having a triangular groove via a second temporary fixing agent;
Mirror polishing of the slopes of a plurality of right triangular prisms mounted on the polishing jig in the second mounting step, and a mirror polishing / peeling step of peeling from the polishing jig;
And a second cutting step of cutting the right triangular prism whose surface is mirror-polished in the mirror polishing / peeling step at a plurality of cutting surfaces having a predetermined pitch perpendicular to the longitudinal direction. Manufacturing method of prism. A method of manufacturing a right triangular prism having first and second optical multilayer films on side surfaces sandwiching a right angle, respectively,
A first optical multilayer film forming step of forming a first optical multilayer film on one surface of a rectangular flat optical member and forming a second optical multilayer film on the other surface;
A laminated body forming step of laminating the plurality of flat optical members via a first temporary fixing agent;
A first cutting step of cutting at a plurality of cut surfaces having a predetermined pitch perpendicular to the main surface of the laminate formed in the laminate formation step;
A mirror polishing step of mirror polishing the cut surface of the laminate divided body cut by the first cutting step;
The first temporary fixing agent of the layered divided body that has been mirror-polished by the mirror-polishing step is peeled off, and a square square is formed on the end surfaces where the first and second optical multilayer films are formed on the two opposing side surfaces. A peeling step to form;
A second optical multilayer film forming step of forming first and second optical multilayer films respectively on two mirror-polished surfaces of the regular quadrangular prism obtained by the peeling step;
A first mounting in which the regular quadratic prism formed with the optical multilayer film in the optical multilayer film forming step is mounted to a cutting jig having a rectangular groove at the tip of the triangular groove through a second temporary fixing agent. Process,
A cutting and peeling step of cutting the regular square column mounted on the cutting jig along the diagonal of the regular square column and peeling from the cutting jig,
A second mounting step of mounting the right triangular prism obtained by the cutting and peeling step on a polishing jig having a triangular groove via a second temporary fixing agent;
Mirror polishing of the slopes of a plurality of right triangular prisms mounted on the polishing jig in the second mounting step, and a mirror polishing / peeling step of peeling from the polishing jig;
And a second cutting step of cutting the right triangular prism whose surface is mirror-polished in the mirror polishing / peeling step at a plurality of cutting surfaces having a predetermined pitch perpendicular to the longitudinal direction. Manufacturing method of prism.

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