JP2008158144A - Manufacturing method of cross prism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a cross prism by which optical characteristics can be improved. <P>SOLUTION: At first two or more planar glass substrates are arranged by stepwise lamination and are temporarily adhered, then are cut with a predetermined angle and a predetermined spacing to form laminating division objects. Then a red light reflective film 13 is formed on one surface of the laminating division object, those are further arranged by stepwise lamination and are really adhered to form a laminate again. Thereafter the laminate is cut with the predetermined angle and the predetermined spacing to form third laminating division objects 42. Then a blue light reflective film 14 is formed on one surface of the third laminating division object 42. Then temporarily adhered part in the third laminating division object 42 is removed to separate the third laminating division object 42 into two or more prism column pairs 51a, 51b. Thereafter the first prism column pair 51a and the second prism column pair 51b are joined by real adhesion. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a cross prism, and more particularly to a method for manufacturing a cross prism in which a plurality of substrates are stacked to manufacture a large number of cross prisms at the same time.

  The above-described cross prism is used for synthesizing three modulated lights (for example, red light, blue light, and green light) such as a color light combining optical system of a projector. This cross prism is a light selection prism (dichroic prism) in which two types of wavelength separation films are formed on a substantially X-shaped interface formed by joining four right-angled isosceles triangular prisms. In the projection display device using this cross prism, the synthesized light can be displayed on the screen.

  A method for manufacturing a cross prism is described in Patent Document 1, for example. According to this, first, in the step shown in FIG. 7A, the rectangular plate-like transparent substrate 111 is temporarily bonded in a stepped manner (for example, 45 ° with respect to the bonding surface of the plate-like transparent substrate 111). The stacked body 112 is formed. Next, in the step shown in FIG. 7B, the first stacked body 112 is cut at a predetermined interval, for example, at a semi-right angle (45 °) to form the first stacked divided body 113. Next, in the step shown in FIG. 7C, after polishing the upper and lower surfaces of the first laminated division body 113, the wavelength separation film former 114 that selects and reflects a certain wavelength is formed.

  Next, in the process illustrated in FIG. 8A, the first stacked divided body 113 is stacked by changing the orientation of the first stacked divided body 113 by 180 ° and is finally bonded using an adhesive to form the second stacked body 121. Next, in the step shown in FIG. 8B, the second stacked body 121 is cut perpendicularly and at a predetermined interval with respect to the upper and lower surfaces 113 a and 113 b of the first stacked divided body 113, thereby A divided body 122 is formed. Next, in the step shown in FIG. 8C, the upper and lower surfaces of the second laminated divided body 122 are polished to form the wavelength separation film B 123.

  Next, in the step shown in FIG. 9A, the second stacked divided body 122 is stacked so that the temporarily bonded temporary bonding surface 131 has a substantially square shape (cross prism shape), and an adhesive is used. The third laminated body 132 is formed by the main bonding. Next, in the step shown in FIG. 9B, the third stacked body 132 is cut in parallel at predetermined intervals along the cutting line L101. As a result, a rectangular plate-shaped cross prism connecting body 141 including a large number of cross prisms 151 is formed. Next, in the step shown in FIG. 9C, the temporarily bonded portion is removed by placing the cross prism coupled body 141 on a hot plate and heating it. And the cross prism 151 which consists of the four right-angled triangular prisms 152 joined by the part which carried out this adhesion | attachment is isolate | separated.

JP 2001-343508 A

  However, at the stage of forming the second layered divided body 122 shown in FIG. 8C, the parallelism when cutting in the previous process (such as the process shown in FIG. 7), the accuracy of the polishing process, the thickness variation of the adhesive, etc. As a result, the pitch error (cumulative error) of the wavelength separation membrane 114 is included. Further, in the step shown in FIG. 9A, the second stacked divided body 122 including the pitch error is stacked to form the third stacked body 132. Therefore, as shown in FIG. A step H is generated at the junction of the wavelength separation membrane shell 114. As a result, when light is passed through the completed cross prism 151a, the reflection characteristics and transmission characteristics of the light passing through the vicinity of the step H are changed, and as a result, the image information to be displayed is degraded, for example, the light is scattered. There's a problem.

  An object of this invention is to provide the manufacturing method of the cross prism which can improve an optical characteristic.

  In order to solve the above problems, a manufacturing method of a cross prism according to the present invention is a manufacturing method of a cross prism formed by adhering four right triangular prisms in a substantially X shape. A plate-like transparent substrate is laminated and temporarily bonded, and the laminated arrangement of the transparent substrates is cut into two or more plate-like shapes at an angle half-perpendicular to the temporary bonding surface, A laminated division forming step for forming a second laminated division, a wavelength separation membrane former forming step for forming a wavelength separation membrane former on one side of the first laminated division and the second laminated division, and After the wavelength separation film former is formed, the first laminated divided body and the second laminated divided body are alternately laminated and sandwiched so as to sandwich the wavelength separation film former, and are adhered to the main adhesion surface. Laminated division body that forms a third laminated division body by cutting into two or more plates at a vertical angle Forming the wavelength separation film B on one side of the third laminated divided body, removing the temporary adhesion portion of the third laminated divided body, and forming the wavelength separation film B A separated layered body separating step for separating the first prism column pair and the second prism column pair in which the wavelength separation film B is not formed, the first prism column pair and the second prism column pair, And a prism column pair joining step for main bonding so as to be substantially square and sandwiching the wavelength separation film B.

  According to this method, after separating the plurality of first prism column pairs and the plurality of second prism column pairs from the stacked divided body, the single first prism column pair and the single second prism column pair are joined. . Therefore, compared to the conventional method of manufacturing a cross prism by joining a laminated segment in which a plurality of prism column pairs are laminated with other laminated segments, it is affected by the pitch error accumulated during processing. The first prism column pair and the second prism column pair can be joined with high accuracy without any problem. Therefore, it is possible to reduce the level difference at the joint between the end portion of the wavelength separation membrane shell sandwiched between the first prism column pair and the end portion of the wavelength separation membrane shell sandwiched between the second prism column pair. Thereby, the bad influence which the level | step difference of a junction part has on the image information which projects can be suppressed.

  The method for manufacturing a cross prism according to the present invention includes a cross prism forming step of forming the cross prism by cutting the joined prism column pair into a length of the cross prism after the prism column pair joining step. Features.

  According to this method, the prism column pair in which the step of the joint portion of the wavelength separation membrane is suppressed by the prism column pair joining process is cut into the size of the cross prism, so that the cross in which the step of the wavelength separation membrane is suppressed. The prism can be completed.

  In the method of manufacturing a cross prism according to the present invention, the prism column pair joining step includes the end of the wavelength separation membrane A sandwiched between the first prism column pair and the second prism column pair. The first prism column pair and the second prism column pair are joined to each other by matching the position with the end of the wavelength separation membrane back.

  According to this method, since the end portions of the wavelength separation membrane are joined together, it is possible to reduce the joining step that greatly affects the performance of the cross prism, and to improve the performance of the cross prism.

  In the method for manufacturing a cross prism according to the present invention, the transparent substrate is optical glass.

  According to this method, since the cross prism is formed using the optical glass, the cross prism can be manufactured without affecting the optical characteristics even if various manufacturing methods (cutting angle or the like) are used.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing the structure of a cross prism. Hereinafter, the structure of the cross prism will be described with reference to FIG.

  As shown in FIG. 1, the cross prism 11 is used, for example, in a color light combining optical system of a projector (for example, combining red light, green light, and blue light). "). The cross prism 11 is made of, for example, optical glass. The cross prism 11 includes a first right-angle prism 12a, a second right-angle prism 12b, a third right-angle prism 12c, and a fourth right-angle prism 12d, and is formed into a right-angled isosceles triangular prism having the same height. . The cross prism 11 is a quadrangular prism (a rectangular parallelepiped or a cube) configured by joining side surfaces 12e of the right-angle prism 12 at right angles to each other with an adhesive (not shown).

  A red light reflecting film 13 (13a, 13b) as a wavelength separating film and a blue light reflecting film 14 as a wavelength separating film B are formed in a substantially X shape on the joint surface formed by four right-angle prisms 12. Is formed. A red light reflecting film 13a constituting the red light reflecting film 13 is formed between the first right angle prism 12a and the second right angle prism 12b. A red light reflecting film 13b constituting the red light reflecting film 13 is formed between the third right angle prism 12c and the fourth right angle prism 12d. As described above, the red light reflection film 13 and the blue light reflection film 14 are formed in a substantially X shape, so that, for example, red light (R), green light (G), It is possible to emit light synthesized from blue light (B). For example, an antireflection film 15 is formed on one surface of the cross prism 11.

  A blue light reflection film 14 is continuously formed between the first right-angle prism 12a and the third right-angle prism 12c, and between the second right-angle prism 12b and the fourth right-angle prism 12d. That is, the blue light reflection film 14 separates the red light reflection film 13a and the red light reflection film 13b.

  The separated red light reflecting film 13a and the red light reflecting film 13b are suppressed from being deteriorated in characteristics (reflection characteristics, transmission characteristics, etc.), although there is a loss due to suppression of the level difference between the joint portions 16. It is done. However, when the level difference of the joint portion 16 is increased, the characteristic is greatly deteriorated. For example, there is a problem that image information to be displayed is deteriorated.

  2 to 6 are perspective views showing a method of manufacturing a cross prism in the order of steps. Hereinafter, the manufacturing method of the cross prism will be described with reference to FIGS. The manufacturing method shown in FIGS. 2 to 6 is a method in which plate-like transparent substrates are stacked in a multistage manner, and a large number of cross prisms can be manufactured at one time.

  In the step shown in FIG. 2A, the upper surface 22 and the lower surface 22 of the rectangular glass substrate 21 made of optical glass are mirror-polished (such as lapping or polishing). Further, since the plurality of glass substrates 21 are used in the subsequent process, mirror polishing is performed on the plurality of glass substrates 21.

  In the step shown in FIG. 2B, an antireflection film 15 (AR film) is formed on the glass substrate 21. Note that the antireflection film 15 may be formed on the glass substrate 21 as necessary. Here, for example, the first glass substrate in which the antireflection film 15 is formed on only one of the surfaces through which light passes in the completed cross prism 11 and the antireflection film 15 is formed on one surface of the glass substrate 21. Two types are formed: 21 a and a second glass substrate 21 b on which the antireflection film 15 is not formed on the glass substrate 21.

  In the step shown in FIG. 2C, the first glass substrate 21a is laminated stepwise and temporarily bonded. In the first glass substrate 21a stacked in a staircase shape, for example, an angle formed by a virtual plane connecting the edge 23 of the first glass substrate 21a and the upper surface or the lower surface of the first glass substrate 21a is 45 °. In order to laminate at 45 °, a jig composed of a horizontal plate-like base (not shown) and an inclined side wall fixed at an inclination angle of 45 ° from the base is fixed. Also good. Then, the first glass substrate 21a is sequentially laminated while being pressed against the inclined side wall of the jig, whereby the first laminated body 24 having a substantially parallelogram shape is obtained.

  A temporary adhesive (not shown) such as paraffin is applied in advance to the bonding surface of the first glass substrate 21a, so that the first glass substrates 21a are temporarily bonded to each other. Moreover, the 2nd laminated body 25 is formed by laminating | stacking the 2nd glass substrate 21b in which the antireflection film 15 is not formed by the method similar to the above. A temporary adhesive other than paraffin, for example, a temporary adhesive that is temporarily cured with UV light and can be removed with warm water may be used.

  In the step shown in FIG. 3A (laminated divided body forming step), the first laminated body 24 and the second laminated body 25 are virtually connected to the edge 23 of the first glass substrate 21a (second glass substrate 21b). Cut along the cutting line L11 at a predetermined interval parallel to the plane (semi-perpendicular 45 ° with respect to the bottom surface of the glass substrate 21). As a method for cutting, for example, a cutting means such as a wire saw is used. The interval between the cutting lines L11 is set according to the size and shape of the cross prism 11 to be finally manufactured. By the cutting as described above, the first stacked divided body 31 and the second stacked divided body 32 shown in FIG. 3B are formed. The 1st lamination division body 31 and the 2nd lamination division body 32 are lamination bodies of a parallelogram whose front shape is horizontally long.

  In the step shown in FIG. 3C, mirror polishing is applied to the upper and lower surfaces 31a of the first stacked divided body 31 and the upper and lower surfaces 32a of the second stacked divided body 32, which are cut surfaces. The mirror polishing process is a lapping process or a polishing process as described above. In addition to the above-described processing method, grinding may be used.

  In the step (wavelength separation film former forming process) shown in FIG. 4A, for example, a red light reflection film 13 (RDM: red dichroic mirror) is provided on the first laminated divided body 31 and the second laminated divided body 32. Form. The red light reflecting film 13 is, for example, a dielectric multilayer film in which inorganic thin films are formed in multiple layers. The red light reflecting film 13 is formed by, for example, a vacuum deposition method or a sputtering method. The red light reflecting film 13 is a reflecting film that reflects components having a wavelength of around 600 nm, for example. First, the red light reflecting film 13 is formed on one surface of the first stacked divided body 31. Next, the red light reflection film 13 is also formed on one surface of the second stacked divided body 32 by, for example, the same method as described above.

  In the step shown in FIG. 4B, the first stacked divided body 31 and the second stacked divided body 32 are alternately stacked and finally bonded to form the third stacked body 41. First, the 1st lamination division body 31 in which antireflection film 15 was formed, and the 2nd lamination division body 32 in which antireflection film 15 was not formed are pasted up using an adhesive (not shown). Examples of the adhesive used for the main adhesion include a UV adhesive. The UV adhesive is cured by using, for example, an ultraviolet light source having output characteristics at a wavelength of 300 nm to 400 nm. If a UV adhesive having a low viscosity is used, the curing time can be shortened and the generation of heat during curing can be reduced.

  First, the first laminated division bodies 31 and the second laminated division bodies 32 are alternately arranged so that the red light reflection film 13 is on the upper surface. At this time, it arrange | positions so that the end surface of the 1st lamination | stacking division body 31 and the 2nd lamination | stacking division body 32 may not become parallel (each other end surface cross | intersects at 90 degrees). The adhesive is applied to either the first layered divided body 31 or the second layered divided body 32 and cured after bonding. Thereafter, in the same procedure, the first stacked divided body 31 and the second stacked divided body 32 are bonded in an alternating manner.

  In the step shown in FIG. 4C (laminated divided body forming step), the third laminated body 41 is cut to form the third laminated divided body 42. The 3rd laminated body 41 is cut | disconnected along the cutting line L12 orthogonal to the upper-lower surfaces 31a and 32a (refer FIG.3 (c)) of the 1st laminated division body 31 and the 2nd laminated division body 32. FIG. Each cutting line L12 is a line along the intersection 43.

  In the step shown in FIG. 5A, the upper and lower surfaces of the third laminated divided body 42 are mirror-polished. The surface to be mirror-polished is a cut surface cut along each cutting line L12. The mirror polishing process is, for example, a lapping process or a polishing process as described above.

  In the step shown in FIG. 5B (wavelength separation film formation step), for example, a blue light reflection film 14 (BDM: blue dichroic mirror) is formed on one surface of the third laminated divided body 42. The blue light reflection film 14 is, for example, a dielectric multilayer film in which inorganic thin films are formed in multiple layers, similarly to the red light reflection film 13. The blue light reflecting film 14 is formed by, for example, a vacuum deposition method or a sputtering method. The blue light reflection film 14 is a reflection film that reflects components having a wavelength of around 450 nm, for example.

  In the step shown in FIG. 5C (laminated divided body separating step), the portion where the third laminated divided body 42 is temporarily bonded is removed to form a plurality of prism column pairs 51 (51a, 51b). By separating the third laminated divided body 42, the first prism column pair 51a on which the blue light reflecting film 14 is formed and the second prism column pair 51b on which the blue light reflecting film 14 is not formed are separated. . As a method for removing the temporary adhesive, for example, a hot plate (not shown) is used. By placing and heating the third laminated divided body 42 on the hot plate, the temporary adhesive is dissolved and removed, and the first prism column pair 51a and the second prism column pair 51b are separated.

  In the step shown in FIG. 6A (prism column pair joining step), the first prism column pair 51a and the second prism column pair 51b are joined so as to be substantially square, and are finally bonded using an adhesive, A cross prism body 61 is formed. As above-mentioned as an adhesive agent used for this adhesion | attachment, UV adhesive agent is mentioned, for example. As described above, the UV adhesive is cured by using, for example, an ultraviolet light source having output characteristics at a wavelength of 300 nm to 400 nm. The adhesive is applied to either the first prism column pair 51a or the second prism column pair 51b, and is cured after bonding.

  As described above, the red light reflecting film 13a is formed between the first right-angle prism 12a and the second right-angle prism 12b constituting the first prism column pair 51a. On the other hand, a red light reflecting film 13b is formed between the third right-angle prism 12c and the fourth right-angle prism 12d constituting the second prism column pair 51b.

  Thus, before joining the end of the red light reflecting film 13a formed on the first prism column pair 51a and the end of the red light reflecting film 13b formed on the second prism column pair 51b, FIG. In the step shown in FIG. 5C, by separating the plurality of prism column pairs 51 (51a, 51b) constituting the third stacked divided body 42, the red light reflecting film 13 included in the third stacked divided body 42 is separated. Pitch error (cumulative error) can be eliminated. As a result, when the cross prism body 61 is formed, it is possible to suppress the occurrence of a step at the junction between the end of the red light reflection film 13a and the end of the red light reflection film 13b.

  Further, in the step shown in FIG. 4C, when cutting from the third stacked body 41 to the third stacked divided body 42, the cutting may be performed with an inclination with respect to the regular cutting line L12. In the prior art, a plurality of prism column pairs 51 (51a, 51b) are joined in a plate shape even if the third laminated divided body 42 is rotated in order to match the surface of the red light reflecting film 13 or the like. Therefore, it is difficult to adjust the angle. However, in the present embodiment, the single stacked first prism column pair 51a and the single second prism column pair 51b are joined by separating the third stacked divided body 42 into prism column pairs 51 (51a and 51b). Therefore, even if the cutting is performed with an inclination with respect to the cutting line L12, the angle between the first prism column pair 51a and the second prism column pair 51b can be easily adjusted. As a result, the conventional film surface angle accuracy of the red light reflecting film 13a and the red light reflecting film 13b can be suppressed to 0 seconds to 30 seconds.

  In the step (cross prism forming step) shown in FIG. 6B, the cross prism body 61 is cut into a predetermined length. The predetermined length is the length of the cross prism 11.

  By the above manufacturing method, the cross prism 11 in which the step between the red light reflecting film 13a and the red light reflecting film 13b is suppressed as shown in FIG. 6C is completed. According to such a manufacturing method, since the third laminated divided body 42 is separated from the temporary adhesion portion in the step shown in FIG. 5C, the red light reflection film is formed as in the step shown in FIG. The cross prism body 61 can be formed by combining the end of 13a and the end of the red light reflecting film 13b. Therefore, the level difference H (see FIG. 10B) can be reduced as compared with the conventional method of joining in a state including the accumulated pitch error. According to this embodiment, the conventional level difference H of 3 μm to 12 μm can be suppressed to 3 μm or less, including the level difference (displacement) on the near side and the back side of the cross prism body 61. As a result, the image projected on the screen can be displayed closer to the regular image than in the conventional case. Furthermore, if a method of laminating a plurality of glass substrates 21 in a multi-stage shape is used, a large number of cross prisms can be formed at a time with further reduced quality variations.

  As described above in detail, according to the method for manufacturing the cross prism 11 of the present embodiment, the following effects can be obtained.

  (1) According to the present embodiment, before joining the first prism column pair 51a and the second prism column pair 51b, in the step shown in FIG. 5C, a plurality of prism column pairs 51 (51a, 51b). ) Is separated, the pitch error of the red light reflecting film 13 accumulated until the third laminated divided body 42 is formed (variation in the spacing between the red light reflecting films 13) is eliminated. It becomes possible. Therefore, in the step shown in FIG. 6A, when the first prism column pair 51a and the second prism column pair 51b are bonded, the red light reflection film 13a and the red light reflection film 13b may be bonded together. it can. Thereby, the highly accurate cross prism 11 in which a step between the red light reflecting film 13a and the red light reflecting film 13b is suppressed can be formed. As a result, for example, light scattering near the junction of the two red light reflecting films 13 (13a, 13b) is eliminated, and an image close to a regular image can be displayed on the screen. Furthermore, since it is possible to select and join the plurality of first prism column pairs 51a and second prism column pairs 51b with the same position of the red light reflecting film 13, the yield can be improved and the production cost can be reduced. be able to.

  (2) According to the present embodiment, since the cross prism 11 is formed from the plate-shaped glass substrate 21, it is possible to reduce the cost compared to a method in which the cross prism 11 is formed by bonding triangular prism raw materials. it can. In addition, if a method of laminating a plurality of glass substrates 21 in a multistage manner is used, a large number of cross prisms 11 can be formed at a time.

  (3) According to the present embodiment, the plate-like first laminated divided body 31 (second laminated divided body 32) and the third laminated divided body 42 are formed from the glass substrate 21, and polishing or red light reflection is formed on these. Since the film 13 and the blue light reflecting film 14 are formed, the film can be processed efficiently and with less variation in quality as compared with the method of processing one by one.

  In addition, embodiment is not limited above, It can also implement with the following forms.

(Modification 1)
As described above, the right-angle prism 12 constituting the cross prism 11 is not limited to a right-angled isosceles triangle, and may have, for example, a triangular prism shape having a substantially right angle.

(Modification 2)
As described above, the wavelength separation film formed on the cross prism 11 is not limited to the red light reflection film 13 and the blue light reflection film 14, and a necessary wavelength separation film (reflection film) may be appropriately selected and formed. desirable.

(Modification 3)
As described above, instead of the forming method of separating the red light reflecting film 13a and the red light reflecting film 13b, the blue light reflecting film 14 may be separated. The wavelength separation film (reflection film) is desirably determined based on the priority order of films that are not desired to be separated.

(Modification 5)
As described above, the cross prism 11 is not limited to being used as a color light combining optical system that combines three lights (for example, red light, green light, and blue light). For example, if the light traveling direction is reversed, It can be used as a color light separation optical system.

(Modification 6)
As described above, in order to attach the antireflection film 15 to one surface of the cross prism 11, it is not limited to forming the antireflection film 15 on one surface of the first glass substrate 21a in the process of FIG. For example, in order to attach the antireflection film 15 to the four surfaces of the cross prism 11, the antireflection film 15 may be formed on both surfaces of the first glass substrate 21a (both surfaces of the second glass substrate 21b). The antireflection film 15 is appropriately selected and formed according to product specifications.

The perspective view which shows the structure of a cross prism typically. The perspective view which shows the manufacturing method of a cross prism in order of a process. The perspective view which shows the manufacturing method of a cross prism in order of a process. The perspective view which shows the manufacturing method of a cross prism in order of a process. The perspective view which shows the manufacturing method of a cross prism in order of a process. The perspective view which shows the manufacturing method of a cross prism in order of a process. Sectional drawing which shows the manufacturing method of the conventional cross prism in order of a process. Sectional drawing which shows the manufacturing method of the conventional cross prism in order of a process. It is a schematic diagram which shows the manufacturing method of the conventional cross prism in order of a process, (a) is sectional drawing, (b) is a perspective view, (c) is a perspective view. Sectional drawing which shows the manufacturing method of the conventional cross prism.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Cross prism, 12 ... Right angle prism, 12a ... 1st right angle prism, 12b ... 2nd right angle prism, 12c ... 3rd right angle prism, 12d ... 4th right angle prism, 12e ... Side surface, 13 ... As wavelength separation film former Red light reflection film, 13a ... Red light reflection film, 13b ... Red light reflection film, 14 ... Blue light reflection film as wavelength separation film, 15 ... Antireflection film, 16 ... Junction, 21 ... Glass as transparent substrate Substrate, 21a ... first glass substrate, 21b ... second glass substrate, 22 ... upper and lower surfaces, 23 ... edge, 24 ... first laminated body, 25 ... second laminated body, 31 ... first laminated divided body, 31a ... Upper and lower surfaces, 32 ... 2nd laminated division body, 32a ... Upper and lower surfaces, 41 ... 3rd laminated body, 42 ... 3rd laminated division body, 43 ... Intersection, 51 ... Prism column pair, 51a ... 1st prism column pair, 51b ... 2nd prism column pair, 61 Cross prism body.

Claims (4)

A method of manufacturing a cross prism formed by adhering four right triangular prisms in a substantially X shape,
Two or more plate-like transparent substrates are stacked and temporarily bonded, and the transparent substrate stacked arrangement is cut into two or more plates at a semi-perpendicular angle to the temporarily bonded surface. A laminated division forming step of forming the first laminated division and the second laminated division;
A wavelength separation membrane former forming step of forming a wavelength separation membrane former on one side of the first lamination division and the second lamination division;
After the wavelength separation film former is formed, the first laminated division body and the second lamination division body are alternately laminated and sandwiched so as to sandwich the wavelength separation film upper, and the main adhesion is performed. A layered divided body forming step of forming a third layered divided body by cutting into two or more sheets at an angle perpendicular to the surface;
A wavelength separation film B forming step of forming a wavelength separation film B on one side of the third laminated divided body;
The temporary separation part of the third laminated division body is removed, and the first prism column pair in which the wavelength separation film B is formed and the second prism column pair in which the wavelength separation film B is not formed are separated A divided body separation step;
A prism column pair joining step for permanently adhering the first prism column pair and the second prism column pair so as to be substantially square and sandwiching the wavelength separation film B;
A method for producing a cross prism, comprising: It is a manufacturing method of the cross prism according to claim 1,
A method of manufacturing a cross prism, comprising: a cross prism forming step of forming the cross prism by cutting the bonded prism column pair into a cross prism length after the prism column pair joining step. A method of manufacturing a cross prism according to claim 1 or 2,
In the prism column pair joining step, the positions of the end of the wavelength separation membrane back sandwiched between the first prism column pair and the end of the wavelength separation membrane back sandwiched between the second prism column pair are determined. A method of manufacturing a cross prism, characterized in that the first prism column pair and the second prism column pair are joined together. It is a manufacturing method of the cross prism according to claim 1,
The method for manufacturing a cross prism, wherein the transparent substrate is optical glass.

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