Prism and method for manufacturing same

Abstract

One embodiment of the present disclosure provides a prism including: a first transmission surface that transmits light; a second transmission surface that transmits the light; and a reflection surface disposed in an optical path of the light between the first transmission surface and the second transmission surface and inclined with respect to the first transmission surface and the second transmission surface. Two of the first transmission surface, the second transmission surface, and the reflection surface have respective end portions adjacent to each other. A rib portion protruding beyond each of the two adjacent surfaces is provided between the end portions of the two adjacent surfaces.

Description

Prism and Method for Manufacturing the Same

[0001] The present disclosure relates to a prism and a method for manufacturing the same.

[0002] A prism is used as a component for dispersing, refracting, etc. light in various optical devices. As such a prism, from the viewpoint of making it difficult to generate streaks or the like, there is shown a prism having a prism body formed in a polygonal prism shape, and at least one of a plurality of ridge line portions of the prism body being formed as an R surface (see Patent Document 1).

[0003] Japanese Patent No. 4653809

[0004] The inventor of the present application newly found that there are points that can be improved in the conventional prism.

[0005] A prism may include a first transmission surface that transmits light, a second transmission surface that transmits light, and a reflection surface that is inclined with respect to the first transmission surface and the second transmission surface. Under such a configuration, for example, light emitted from a light source enters the first transmission surface, is reflected by the reflection surface, and exits from the second transmission surface.

[0006] In an optical device, it is necessary to accurately emit light emitted from a light source to a predetermined location from the prism after reflecting the light by the reflection surface of the prism. For this purpose, it is necessary to accurately attach the prism to a predetermined location of the optical device without misalignment.

[0007] Therefore, an object of the present disclosure is to provide a prism and a method for manufacturing the same that can accurately perform attachment to a predetermined location of an optical device.

[0008] To achieve the above object, in one embodiment of the present disclosure, a first transmission surface that transmits light, the second transmission surface that transmits the light, and a reflection surface that is disposed in an optical path of the light between the first transmission surface and the second transmission surface and is inclined with respect to the first transmission surface and the second transmission surface, and two of the first transmission surface, the second transmission surface, and the reflection surface each have an end portion that is close to each other, and a rib portion that protrudes more than each of the two close surfaces is provided between the end portions of the two close surfaces. A prism is provided.

[0009] To achieve the above objective, one embodiment of the present disclosure provides a method for manufacturing a prism using a molding apparatus having a first mold and a second mold arranged in the pressurizing direction for forming a mold cavity, and a body mold arranged in a direction intersecting the pressurizing direction, the method comprising press-working a prism material in the pressurizing direction in the mold cavity, wherein the first mold and the second mold each have a first opposing surface and a second opposing surface that face each other and are capable of contacting the prism material, the first opposing surface includes an inclined surface inclined with respect to the second opposing surface, the second opposing surface has a recess at its end that is recessed in the pressurizing direction from its center, and the first opposing surface has an inclined surface that faces the center of the second opposing surface and an end surface that faces the end of the second opposing surface, is continuous with the inclined surface, and is located outside the inclined surface.

[0010] According to one embodiment of the present disclosure, it is possible to provide a prism that can be accurately mounted to a predetermined location on an optical instrument.

[0011] Figure 1 is a schematic perspective view showing a prism according to the first embodiment of this disclosure. Figure 2 is a schematic front view showing a prism according to the first embodiment of this disclosure. Figure 3 is a schematic front view showing an example of an optical device equipped with the prism according to the first embodiment of this disclosure. Figure 4 is a schematic perspective view showing an example of a specific configuration of the prism according to the first embodiment of this disclosure. Figure 5 is a schematic perspective view showing another example of a specific configuration of the prism according to the first embodiment of this disclosure. Figure 6 is a schematic front view showing a prism according to the second embodiment of this disclosure. Figure 7 is a schematic front view showing an example of an optical device equipped with the prism according to the second embodiment of this disclosure. Figure 8 is a schematic perspective view showing an example of a specific configuration of the prism according to the second embodiment of this disclosure. Figure 9 is a schematic perspective view showing another example of a specific configuration of the prism according to the second embodiment of this disclosure. Figure 10 is a schematic front view showing a prism according to the third embodiment of this disclosure. Figure 11 is a schematic cross-sectional view showing the state of the prism material before press processing in a prism manufacturing method according to one embodiment of this disclosure. Figure 12 is a schematic cross-sectional view showing the state of the prism material during press processing in a prism manufacturing method according to one embodiment of the present disclosure.

[0012] [Prism] The prism of this disclosure will be described in detail below with reference to the drawings.

[0013] The various elements in the drawings are provided for illustrative purposes only to help understand the prism and its manufacturing method described herein, and their appearance and dimensional ratios may differ from those of the actual product. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the disclosure and are not intended to limit the subject matter described in the claims.

[0014] (First Embodiment) The prism according to the first embodiment will be described below. Figure 1 is a schematic perspective view showing the prism according to the first embodiment of the present disclosure. Figure 2 is a schematic front view showing the prism according to the first embodiment of the present disclosure. Figure 3 is a schematic front view showing an example of an optical device equipped with the prism according to the first embodiment of the present disclosure. Figure 4 is a schematic perspective view showing an example of a specific configuration of the prism according to the first embodiment of the present disclosure. Figure 5 is a schematic perspective view showing another example of a specific configuration of the prism according to the first embodiment of the present disclosure. Note that the front views in Figures 2 and 3 correspond to views of the first end face of the prism, as described below, as seen from the front.

[0015] As shown in Figures 1 and 2, the prism 100 according to the first embodiment of this disclosure has a polygonal prism shape and includes, as its multiple sides, a first light-transmitting surface 10, a second light-transmitting surface 20, and a reflective surface 30. The polygonal prism shape can be, for example, a triangular prism shape, a pentagonal prism shape, etc. The reflective surface 30 is positioned in the optical path of light between the first light-transmitting surface 10 and the second light-transmitting surface 20 and is a reflective surface that is inclined with respect to the first light-transmitting surface 10 and the second light-transmitting surface 20.

[0016] In the first embodiment, as shown in the figure, a lens portion 13 is formed on the first transmissive surface 10. The lens portion 13 helps to make the light emitted from the light source (for example, diffused light) parallel as a whole when directed toward the reflective surface within the prism 100. The prism 100 also has a first end surface 40 and a second end surface 50 opposite each other as its end faces.

[0017] In the prism 100, the first transmission surface 10, the second transmission surface 20, and the reflective surface 30 constitute the optical functional surfaces, while the first end surface 40 and the second end surface 50 constitute the non-optical functional surfaces. Here, an optical functional surface refers to a surface that performs an optical function by actually transmitting or reflecting the necessary light. A non-optical functional surface refers to a surface that does not perform an optical function by not transmitting or reflecting the necessary light.

[0018] The first transparent surface 10 has a first end 11 on one side and a second end 12 on the other side in the X direction as shown in Figure 2. The second transparent surface 20 has a first end 21 on one side and a second end 22 on the other side in the Y direction as shown in Figure 2. The reflective surface 30 has a first end 31 on one side and a second end 32 on the other side in the XY plane as shown in Figure 2.

[0019] As shown in Figure 2, the first end 11 of the first transmissive surface 10 and the first end 31 of the reflective surface 30 are close to each other. Also, the second end 12 of the first transmissive surface 10 and the first end 21 of the second transmissive surface 20 are close to each other. The second end 22 of the second transmissive surface 20 and the second end 32 of the reflective surface 30 are close to each other.

[0020] In the configuration described above, the first embodiment of this disclosure is characterized in that a rib portion 60 is provided between the ends of two adjacent surfaces among the first transmissive surface 10, the second transmissive surface 20, and the reflective surface 30, protruding more than each of the two adjacent surfaces. The term "two adjacent surfaces" here may include not only two surfaces that are adjacent to each other, but also two surfaces that are located on one side and the other side, separated by another surface.

[0021] In the embodiment shown in Figure 2 as an example, a rib portion 60 is provided between the first end 11 of the first transmission surface 10 and the first end 31 of the reflection surface 30, which are adjacent to each other, and the rib portion 60 protrudes more than the adjacent first transmission surface 10 and reflection surface 30, respectively. The presence of such a rib portion 60 makes it possible to accurately mount the prism 100 to a predetermined location on the optical instrument.

[0022] Specifically, the optical instrument 500 equipped with the prism 100 includes, in addition to the prism 100, a light source 200 and a component (support component) 300 that supports the prism and the light source 200 (see Figure 3). In the embodiment shown in Figure 3, light L emitted from the light source 200 is incident on the lens 13 of the first transmission surface 10, and the lens 13 is a collimating lens, so that the light L (diffuse light) passes through the lens 13 and becomes parallel light, which is reflected by the reflective surface 30 inside the prism and can be emitted from the second transmission surface 20. Under this configuration, the light source 200 and the prism 100 are arranged such that the light source 200 and the top 14 of the lens portion 13 of the prism 100 are separated by a predetermined distance D.

[0023] Furthermore, in order to allow light L emitted from the light source 200 to enter the lens 13 of the first transmissive surface 10, be reflected by the reflective surface 30, and be suitably emitted from the second transmissive surface 20, the inclination angle between each of the first transmissive surface 10 and the second transmissive surface 20 and the reflective surface 30 can be 30° or more and 60° or less.

[0024] The support component 300 has a first support portion 310, a second support portion 320, and a third support portion 330. The second support portion 320 is positioned on the first support portion 310 and is capable of supporting the prism 100. Specifically, the second support portion 320 has a space 321 into which the rib portion 60 of the prism 100 can be fitted. The third support portion 330 is positioned on the first support portion 310 and is capable of supporting the light source 200. In the embodiment shown in Figure 3, a semiconductor laser (LD) that emits diffuse light to the prism 100 can be used as the light source 200.

[0025] More specifically, as shown in Figure 3, the rib portion 60 has a plurality of main surfaces. In the first embodiment, the rib portion 60 has a first main surface 61 that contacts the upper surface of the first support portion 310, a second main surface 62 that contacts one side surface constituting the space 321 of the second support portion 320, and a third main surface 63 that contacts the other side surface opposite to the first side surface. In this case, at least the first main surface 61 of the rib portion 60 can function as a mounting surface with the component (corresponding to the support component 300) on which the prism 100 is installed. From the viewpoint of suitably installing the rib portion 60 on such component, it is preferable that the mounting surface (i.e., the main surface of the rib 60) is flat.

[0026] Adhesive is applied to connect and fix the second main surface 62 of the rib 60 to the side surface that constitutes the space 321 of the second support portion 320. In this case, if the adhesive leaks, there is a risk that the adhesive will seep out upwards along the second main surface 62 of the rib 60. However, because there is a slope on the rib portion 60 (corresponding to the slope interposed between the first end 11 of the first transmissive surface 10 and the second main surface 62 of the rib 60), the adhesive is prevented from flowing excessively upwards above the application point, thereby suppressing the influence of the adhesive on the optical surface of the lens 13, etc.

[0027] With the above configuration, compared to the case where the rib portion 60 is not provided (for example, when the first end 11 of the first transmissive surface 10 and the first end 31 of the reflective surface 30 are in contact), the presence of the rib portion 60 makes it possible to fit the rib portion 60 into the space 321 formed in the support component 300 of the optical instrument 500.

[0028] This allows the prism 100 to be precisely mounted on a predetermined location in the optical device 500 without misalignment. In other words, the rib portion 60 can function as a positioning rib portion that defines the positional relationship between the prism 100 and the component on which it is installed. As a result, the light emitted from the light source 200 can be reflected by the reflective surface 30 of the prism 100 and then precisely emitted from the prism 100 toward the predetermined location.

[0029] The presence of these rib portions 60 makes it possible to suppress the occurrence of chipping and breakage due to external impacts during transport of the prism 100, when the prism 100 is attached to the components of the optical instrument 500, etc., compared to the case where the first ends of the first transmission surface 10 and the reflective surface 30, which are close to each other, intersect at an acute angle of 30° to 60°. This makes it possible to ensure the desired prism performance.

[0030] It is preferable that the rib portion 60 protrudes more than the first transmissive surface 10 in the direction perpendicular to the first transmissive surface 10. With this configuration, even if the prism 100 comes into contact with an external medium when it is installed, the rib portion 60 will make contact first, preventing the first transmissive surface 10 from coming into contact. This prevents damage to the first transmissive surface 10.

[0031] Furthermore, it is preferable that the rib portion 60 protrudes in the thickness direction of the lens portion 13 beyond the thickness of the lens portion 13. With this configuration, even if the prism 100 comes into contact with an external medium when it is installed, the rib portion 60 will make contact first, preventing the lens portion 13 from coming into contact. This prevents damage to the lens portion 13.

[0032] In the configuration shown in Figure 3, since the light source 200 emits diffused light to the prism 100, the lens portion 13 is required to convert the diffused light into light that is parallel overall towards the reflective surface 30 within the prism 100. To this end, it is necessary to accurately determine the above-mentioned separation distance D between the light source 200 and the top portion 14 of the lens portion 13 of the prism 100. From this viewpoint, the prism 100 used in the configuration shown in Figure 3 is equipped with a rib portion 60 between the first end portion 11 of the first transmitting surface 10 and the first end portion 31 of the reflective surface 30, which are in close proximity to each other, as described above.

[0033] Although not particularly limited, multiple lens portions 13 may be arranged on the first transmission surface 10 as the incident surface (see Figures 4 and 5). In one example, as shown in Figure 4, the prism 101 may have multiple lens portions 13 arranged in series at predetermined intervals in the Z direction shown in Figure 4 on the first transmission surface 10. In another example, as shown in Figure 5, the prism 102 may have multiple lens portions 13 arranged in a matrix (or arrangement) at predetermined intervals in the X and Z directions on the first transmission surface 10. By arranging multiple lens portions 13, it is possible to easily convert diffused light from the light source 200 into light that is parallel as a whole towards the reflective surface 30 within the prisms 101 and 102.

[0034] In the prism 100, a chamfered portion 80 can be provided between the second end 22 of the second transmission surface 20 and the second end 32 of the reflective surface 30 adjacent to the second end 22 of the second transmission surface 20. By providing the chamfered portion 80, compared to the case where the adjacent second ends of the second transmission surface 20 and the reflective surface 30 intersect at an acute angle of 30° to 60°, the occurrence of chipping and breakage due to external impacts during transport of the prism 100, when the prism 100 is attached to the components of the optical instrument 500, etc., can be suppressed. This makes it possible to ensure the desired prism performance.

[0035] For example, glass material can be used as the material for the prism 100. The glass material is not particularly limited, but any material that transmits visible light and has a low melting point with a low glass transition temperature is acceptable. Examples include glass with a low refractive index (K-PBK40 manufactured by Sumida Optical Glass) or glass with a high refractive index (K-VC89 manufactured by Sumida Optical Glass). However, it is not limited to these, and any press-molded optical glass material is acceptable. In addition, chalcogenide and / or chalcohalide glass can be used. Chalcogenide and / or chalcohalide materials may have suitable transmission characteristics for the infrared region or for both the infrared and visible light regions. Therefore, the prism 100 of this disclosure can be suitably used as a lens for transmitting light rays in at least the infrared region.

[0036] In this context, "chalcogenide material" refers to a material whose main component is at least one chalcogen element selected from the group consisting of S (sulfur), Se (selenium), and Te (tellurium) in Group VIb of the periodic table. For example, a chalcogenide material may have a composition in which at least one chalcogen element selected from the group consisting of S (sulfur), Se (selenium), and Te (tellurium) is combined with at least one element selected from the group consisting of Ge (germanium), As (arsenic), Sb (antimony), P (phosphorus), Ga (gallium), In (indium), and Si (silicon).

[0037] In this context, "chalcohalide material" refers to a material having a composition in which a halogen element (at least one selected from the group consisting of fluorine, chlorine, bromine, and iodine) or a compound thereof is introduced into a chalcogenide material.

[0038] The prism according to the second embodiment will be described below. In the second embodiment, in order to avoid repetition of the explanation, the differences from the first embodiment will be the main focus of the description. In addition, in the second embodiment, parts that overlap with the content of the first embodiment will be simplified or omitted.

[0039] (Second Embodiment) Figure 6 is a schematic front view showing a prism according to the second embodiment of the present disclosure. Figure 7 is a schematic front view showing an example of an optical device equipped with the prism according to the second embodiment of the present disclosure. Figure 8 is a schematic perspective view showing an example of a specific configuration of the prism according to the second embodiment of the present disclosure. Figure 9 is a schematic perspective view showing another example of a specific configuration of the prism according to the second embodiment of the present disclosure.

[0040] As will be described later, the prism 100A according to the second embodiment differs from the prism 100 according to the first embodiment in that it has a rib portion 60 between the second end portion 22 of the second transmission surface 10 and the second end portion 32 of the reflection surface 30, which are in close proximity to each other.

[0041] In the second embodiment, similar to the first embodiment, the first transparent surface 10 has a first end 11 on one side and a second end 12 on the other side in the Y direction as shown in Figure 6. The second transparent surface 20 has a first end 21 on one side and a second end 22 on the other side in the X direction as shown in Figure 6. The reflective surface 30 has a first end 31 on one side and a second end 32 on the other side in the XY plane as shown in Figure 6.

[0042] As shown in Figure 6, the first end 11 of the first transmissive surface 10 and the first end 31 of the reflective surface 30 are close to each other. Also, the second end 12 of the first transmissive surface 10 and the first end 21 of the second transmissive surface 20 are close to each other. The second end 22 of the second transmissive surface 20 and the second end 32 of the reflective surface 30 are close to each other.

[0043] In the above configuration, as illustrated in the example shown in Figure 6, the prism 100A is provided with a rib portion 60 that protrudes from the adjacent second transmission surface 10 and reflective surface 30, respectively, between the second end 22 of the second transmission surface 10 and the second end 32 of the reflective surface 30, which are in close proximity to each other. The presence of such a rib portion 60 makes it possible to mount the optical instrument to a predetermined location with high precision.

[0044] Specifically, the optical device 500A including the prism 100A includes, in addition to the prism 100A, a light source 200A, components (support components) 300A for supporting the prism and the light source 200A, and a light receiving element 400 (see FIG. 7). The light source 200A and the top 14 of the lens portion 13 of the prism 100A are separated by a predetermined distance D1, and the light source 200A, the prism 100A, and the light receiving element 400 are arranged such that the second transmission surface 20 of the prism 100A and the light receiving element 400 are separated by a predetermined distance D2.

[0045] In the embodiment shown in FIG. 7, the light L1 emitted from the light source 200A is incident on the lens 13 of the first transmission surface 10, reflected by the reflection surface 30, and can be emitted from the second transmission surface 20. Thereafter, the light L2 emitted from the prism 100A is condensed on the light receiving element 400. The light (beam) incident on the lens 13 is refracted and bent, and is further refracted and bent when passing through the emission surface, and thus is condensed and incident on the light receiving element 400.

[0046] The support component 300A has a first support portion 310A, a second support portion 320A, and a third support portion 330A. The second support portion 320A is disposed on the first support portion 310A and can support the rib portion 60 of the prism 100A. Specifically, the second support portion 320A has a step portion 321A that can engage with the rib portion 60 of the prism 100A. The third support portion 330A is disposed on the first support portion 310A and can support the light source 200A and the first end portion 21 side of the second transmission surface 20. In the embodiment shown in FIG. 7, as the light source 200A, a spectroscope that emits parallel light with respect to the prism 100A can be used.

[0047] According to the above configuration, compared with the case where the rib portion 60 is not provided (for example, when the second end portion 22 of the second transmission surface 20 and the second end portion 32 of the reflection surface 30 intersect at an acute corner), due to the presence of the rib portion 60, it becomes possible to engage the rib portion 60 with the step portion 321A formed in the second support portion 320A of the support component 300A of the optical device 500A.

[0048] As a result, the prism 100A can be accurately attached to a predetermined position of the optical device 500A without misalignment. As a result, the light emitted from the light source 200A can be reflected by the reflecting surface 30 of the prism 100A and then emitted from the second transmission surface 20 of the prism 100A. Thereafter, the emitted light L2 can be condensed by the light receiving element 400.

[0049] Further, as shown in FIG. 7, the rib portion 60 has a plurality of main surfaces. Two main surfaces of the rib portion 60 are respectively in contact with the bottom surface, which is a component of the step portion 321A of the second support portion 320A, and the side surface continuous with the bottom surface. In this case, the two main surfaces of the rib portion 60 can function as installation surfaces with respect to a component on which the prism 100A is installed (specifically, corresponding to the second support portion 320A of the support component 300A). From the viewpoint of suitably performing the installation of the rib portion 60 with respect to such a component, the installation surface (that is, the main surface of the rib 60) is preferably flat.

[0050] In the embodiment shown in FIG. 7, in order to accurately condense the light L2 emitted from the prism 100A to a local portion of the light receiving element 400, it is necessary to accurately determine the separation distance D1 between the light source 200A and the top 14 of the lens portion 13 of the prism 100A, and the separation distance D2 between the second transmission surface 20 of the prism 100A and the light receiving element 400. From this viewpoint, for the prism 100A used in the embodiment shown in FIG. 7, as described above, the one provided with the rib portion 60 between the second end portion 22 of the second transmission surface 20 and the second end portion 32 of the reflecting surface 30, which are close to each other, is used.

[0051] While not particularly limited, multiple lens portions 13 may be arranged on the first transmission surface 10 as the incident surface, similar to the first embodiment (see Figures 8 and 9). In one example, as shown in Figure 8, the prism 101A may have multiple lens portions 13 arranged in series at predetermined intervals in the Z direction shown in Figure 8 of the first transmission surface 10. In another example, as shown in Figure 9, the prism 102A may have multiple lens portions 13 arranged in a matrix (or arrangement) at predetermined intervals in the Y and Z directions shown in Figure 9 of the first transmission surface 10. By arranging multiple lens portions 13, it is possible to easily convert the light from the light source 200 into light that is parallel as a whole towards the reflective surface 30 within the prisms 101A and 102A.

[0052] In the prism 100A, a chamfered portion 90 can be provided between the first end 11 of the first transmission surface 10 and the first end 31 of the reflective surface 30 adjacent to the first end 11 of the first transmission surface 10. By providing the chamfered portion 90, compared to the case where the first ends of the first transmission surface 10 and the reflective surface 30 that are close to each other intersect at an acute angle of 30° to 60°, the occurrence of chipping and breakage due to external impacts during transport of the prism 100A, when the prism 100A is attached to the components of the optical instrument 500A, etc., can be suppressed. This makes it possible to ensure the desired prism performance.

[0053] Furthermore, in the first embodiment described above, a rib portion 60 is provided between the first end 11 of the first transmissive surface 10 and the first end 31 of the reflective surface 30, which are in close proximity to each other, and the rib portion 60 is provided between the second end 22 of the second transmissive surface 10 and the second end 32 of the reflective surface 30, which are in close proximity to each other, and these two aspects were explained separately.

[0054] In this regard, from the viewpoint of further avoiding misalignment of the prism relative to a predetermined location in the optical instrument, a combination of the features of these two embodiments can be adopted. Specifically, a configuration can be adopted in which a rib portion 60 protruding from each of these two adjacent surfaces is provided between the first end 11 of the first transmission surface 10 and the first end 31 of the reflection surface 30, and a rib portion 60 protruding from each of these two adjacent surfaces is provided between the second end 22 of the second transmission surface 10 and the second end 32 of the reflection surface 30.

[0055] It is preferable that the rib portion 60 protrudes more than the second transmissive surface 20 in the direction perpendicular to the second transmissive surface 20. With this configuration, even if the prism 100 comes into contact with an external medium during installation, the rib portion 60 will make contact first, preventing contact with the second transmissive surface 20. This prevents damage to the second transmissive surface 20.

[0056] (Third Embodiment) The prism according to the third embodiment will be described below. In the third embodiment, as with the second embodiment, the differences from the first embodiment will be described in order to avoid repetition of the explanation. In addition, in the third embodiment, the description will be simplified or omitted in parts that overlap with the content of the first embodiment.

[0057] Figure 10 is a schematic front view showing a prism according to the third embodiment of this disclosure. The prism 100B according to the third embodiment differs from the prism 100 according to the first embodiment in that it has two rib portions. Specifically, a rib portion 60 is provided between the first end 11 of the first transmission surface 10 and the first end 31 of the reflection surface 30, which are close to each other, and which protrudes more than each of these two close surfaces. In addition, a second rib portion 70 is provided between the second end 12 of the first transmission surface 10 and the first end 21 of the second transmission surface 20, which are close to each other, and which protrudes more than each of these two close surfaces.

[0058] Similar to the rib portion 60, the provision of the second rib portion 70 makes it possible to suppress the occurrence of chipping and breakage due to external impacts during transport of the prism 100B, when the prism 100B is attached to the components of the optical instrument 500, etc., compared to the case where the first end 21 of the second transmissive surface 20 and the second end 12 of the first transmissive surface 10, which are in close proximity to each other, intersect at an acute angle of 30° to 60°. This makes it possible to ensure the desired prism performance.

[0059] For example, in an optical instrument equipped with a prism 100B, the prism 100B can be supported by two support portions. In this case, as an example, one of the two support portions may have a stepped portion that can engage with the rib portion 60 of the prism 100B, and the other of the two support portions may have a stepped portion that can engage with the second rib portion 70 of the prism 100B.

[0060] With the above configuration, compared to the case where only the rib portion 60 is provided, the presence of both the rib portion 60 and the second rib portion 70 makes it possible to engage the rib portion 60 with a stepped portion formed on one of the two support portions of the support component of the optical instrument, and to engage the second rib portion 70 with a stepped portion formed on the other.

[0061] This makes it possible to accurately mount the prism 100B to a predetermined location on the optical instrument without misalignment. In other words, the presence of the rib portion 60 and the second rib portion 70 makes it possible to mount the prism 100B to a predetermined location on the optical instrument with greater precision.

[0062] In the third embodiment, as shown in Figure 10, in addition to the two rib portions, a chamfered portion 80 can be provided between the second end 22 of the second transmissive surface 20 and the second end 32 of the reflective surface 30 adjacent to it, similar to the first embodiment. The presence of such a chamfered portion 80 makes it possible to suppress the occurrence of chipping and breakage due to external impacts, compared to the case where the adjacent second ends of the second transmissive surface 20 and the reflective surface 30 intersect at an acute angle of 30° to 60°. In the third embodiment, however, it is not limited to this, and a third rib portion may be provided instead of the chamfered portion 80.

[0063] [Method for Manufacturing a Prism] The method for manufacturing the prism of this disclosure will be described in detail below with reference to the drawings.

[0064] Figure 11 is a schematic cross-sectional view showing the state of the prism material before press working in a prism manufacturing method according to one embodiment of the present disclosure. Figure 12 is a schematic cross-sectional view showing the state of the prism material during press working in a prism manufacturing method according to one embodiment of the present disclosure.

[0065] In carrying out the method for manufacturing a prism according to one embodiment of this disclosure, a molding apparatus 1000 having the configuration shown in Figure 11 is used. The molding apparatus 1000 shown in Figure 11 is an apparatus for obtaining the prism 100 according to the first embodiment described above as an example. Differences in configuration between the molding apparatus for obtaining the prisms according to the second and third embodiments described above and the molding apparatus 1000 shown in Figure 11 will be described later. The pressurizing direction P corresponds to the Y direction of the prism 100 in Figure 2.

[0066] The molding apparatus 1000 includes a first mold 710 and a second mold 720 arranged in the pressurizing direction P, a body mold 800 arranged in a direction intersecting the pressurizing direction P, and a first heater section 610 and a second heater section 620 that are in contact with the first mold 710 and the second mold, respectively. In one example, the first mold 710 corresponds to the upper mold and the second mold 720 corresponds to the lower mold. The body mold 800 surrounds the region between the first mold 710 and the second mold 720 to which the prism material M is supplied.

[0067] Specifically, the first type 710 and the second type 720 each have a first opposing surface 711 and a second opposing surface 721 that face each other and are capable of contacting the prism material M. The body type 800 also has an inner body type 810 and an outer body type 820 that surrounds the inner body type 810.

[0068] In this configuration, the inner body mold 810 of the body mold 800 may be positioned to surround the region between the first opposing surface 711 of the first mold 710 and the second opposing surface 721 of the second mold 720. This arrangement can form a mold cavity (which may also be called an internal space) capable of holding the prism material M.

[0069] The first heater unit 610 is configured to heat the first mold 710, and the second heater unit 620 is configured to heat the second mold 720. By heating the first mold 710 and the second mold 720 in this way, the prism material M that can come into contact with the opposing surfaces of each mold can be heated. From the viewpoint of suitably heating the prism material M, the components of the molding apparatus 1000 shown above (first mold 710, second mold 720, and body mold 800) are made of metal members such as copper.

[0070] The first opposing surface 711 of the first type 710 includes an inclined surface 712 that is inclined with respect to the second opposing surface 721 of the second type 720, and end faces 715 and 716 that are continuous with the inclined surface 712 and located outside the inclined surface 712. The second opposing surface 721 of the second type 720 has a recess 723 at its end that is recessed in the direction of pressure P from the central portion 722 in the direction of pressure P.

[0071] Specifically, the inclined surface 712 of the first opposing surface 711 is inclined and faces the central portion 722 of the second opposing surface 721. Furthermore, the end faces 715 and 716 of the first opposing surface 711 face the end of the second opposing surface 721 of the second die 720, and as described above, are continuous with the inclined surface 712 and located outside the inclined surface 712. With this configuration, upon completion of the press work described below, the spatial volume of the die cavity can be made to be greater than or equal to the volume of the prism material M located within the die cavity.

[0072] Furthermore, in a cross-sectional view in the pressurizing direction P, the first end 713 of the inclined surface 712 is close to the first end 724 of the second opposing surface 721. In other words, the second opposing surface 721 of the second type 720 has the recess 723 on the side of the first end 724 that is close to the first opposing surface 711. On the other hand, the second end 714 of the inclined surface 712 is located further away from the second opposing surface 721 than the first end 713.

[0073] According to the above configuration, in cross-sectional view, the inclined surface 712 may be located inward from both ends of the first opposing surface 711. In this case, both end faces 715 and 716 of the first opposing surface 711 may be horizontal planes extending in a direction perpendicular to the pressing direction P in cross-sectional view. That is, both end faces 715 and 716 of the first opposing surface 711 may be horizontal planes. With this configuration, not only rib portions but also chamfered portions can be formed in the prism that is finally formed through the press working process of the prism material described later (3).

[0074] The following explanation will be given using the molding apparatus 1000 having the above configuration as an example to manufacture a prism according to the first embodiment. The method for manufacturing a prism can be broadly divided into the following steps: 1) supplying prism material into the molding apparatus 1000, 2) heating the prism material, 3) pressing the prism material, 4) cooling the pressed prism material, and 5) removing the prism.

[0075] 1) Process of supplying prism material into the molding apparatus First, the prism material M is supplied with the first mold 710 separated from the second mold 720 by a predetermined distance (see Figure 11). As the prism material M, for example, a ball-shaped glass material can be used. As the ball-shaped glass material, for example, K-VC89 manufactured by Sumida Optical Glass Co., Ltd. (glass transition point T: 528°C, inflection point At = 559°C), with a diameter of 0.8 mm can be used.

[0076] 2) Heating process for prism material After supplying the prism material M, the first mold 710 and the second mold 720 are heated using the first heater section 610 and the second heater section 620, respectively. Through this heating of the molds, the prism material M in the mold cavity is heated to a predetermined temperature (near the bending point (approximately 560°C to approximately 600°C, for example, approximately 580°C)). The heating time may be 90 seconds to 120 seconds, for example, 100 seconds.

[0077] 3) Pressing process of prism material Next, the prism material M is heated and then pressed (see Figure 12). For example, using a cylinder or the like that connects the first mold 710 and the second mold 720, the first mold 710 is slid in the pressing direction P so that the first mold 710 approaches the second mold 720. The pressing time may be 90 to 120 seconds, for example 100 seconds. The pressing force on the prism material M may be 20 kgF to 40 kgF, for example 30 kgF.

[0078] In this disclosure, the volume of the mold cavity is set to be greater than or equal to the volume of the prism material M at the completion of the press working. In particular, when the volume of the mold cavity is set to be greater than the volume of the prism material M at the completion of the press working, the rib portion, which is a component of the prism that is ultimately obtained, is not completely filled and molded, and an untransferred portion can be left in part of the obtained rib portion. By forming such an untransferred portion, it is possible to make the local region of the prism material M variable even if there is volume variation in the prism material M, compared to when no untransferred portion is formed. As a result, it is possible to suppress the occurrence of chipping and breakage during manufacturing.

[0079] 4) Cooling process for press-formed prism material After press-forming the prism material M, the temperature of the prism material M is cooled to a temperature lower than Tg (glass transition temperature) (for example, the temperature of the prism material M after press-forming is 100°C or lower).

[0080] 5) At the end of the prism removal process, the first mold 710 is slid away from the second mold 720 in the pressurizing direction P, thereby opening the mold. After that, the molded prism according to one embodiment of the present disclosure is removed.

[0081] The final prism is formed from a ball-shaped glass material with a diameter of 0.8 mm, as described above, and has an outer diameter of 1.0 mm or less. Such a prism has a polygonal prism shape and includes a first transmission surface 10, a second transmission surface 20, and a reflective surface 30 as its multiple sides. The reflective surface 30 is a reflective surface that is inclined with respect to the first transmission surface 10 and the second transmission surface 20.

[0082] The first transmissive surface 10 corresponds to the shape of the second opposing surface 721 of the second type 720 described above, excluding the recess 723 provided on the first end 724 side. The reflective surface 30 corresponds to the shape of the inclined surface 712 of the first type 710 described above. The second transmissive surface 20 corresponds to the shape between the end 716 of the first opposing surface 710 of the first type 710 and the second end 726 of the second opposing surface 721. The end 716 of the first opposing surface 710 of the first type 710 described above corresponds to the end of the first opposing surface 710 located outside the second end 714 of the inclined surface 712. The second end 726 of the second opposing surface 721 described above corresponds to the end opposite to the first end 724 of the second opposing surface 721 described above.

[0083] Furthermore, in the resulting prism, a rib portion 60 is provided between the ends of two adjacent surfaces among the first transmitting surface 10, the second transmitting surface 20, and the reflecting surface 30, protruding more than each of these two adjacent surfaces. Taking the prism 100 according to the first embodiment as an example, a rib portion 60 is provided between the first end 11 of the first transmitting surface 10 and the first end 31 of the reflecting surface 30, which are adjacent to each other, protruding more than each of these two adjacent surfaces. The presence of such a rib portion 60 makes it possible to mount the optical instrument to a predetermined location with high precision.

[0084] Furthermore, in order to obtain the prism 100 of the first embodiment described above, the molding apparatus 1000 has a second recess 725 in the central region of the second opposing surface 721 of the second mold 720 in a cross-sectional view in the pressurizing direction P (see Figure 12). Due to the presence of this second recess 725, the lens portion can be integrally formed in the prism that is finally formed through the press working process of the prism material described in 3) above.

[0085] The recess 723 of the second opposing surface 721 for obtaining the rib portion 60 is located away from the second recess 725 for obtaining the lens portion. Due to this positional relationship, the rib portion and lens portion of the prism that are ultimately obtained can be configured to be separated by a predetermined distance. Because of this configuration, after molding, as described above, it is possible to leave an untransferred portion on a part of the rib portion of the prism, while the lens portion can be configured to have no untransferred portion. In other words, the influence on the transferability of the lens portion can be suppressed, and as a result, it is possible to form the lens portion suitably.

[0086] On the other hand, as a molding apparatus for obtaining the prism 100A according to the second embodiment, compared to the molding apparatus 1000 shown in Figures 11 and 12, an inner body mold 810 that forms part of the mold cavity, located between the end 716 of the first opposing surface 710 of the first mold 710 and the second end 726 of the second opposing surface 721, can be used in which the inner body mold 810 has a partially curved outer surface. The inner body mold 810 is a split mold, and when removing the prism after cooling, the first mold 710 is slid to open the mold so that the first mold 710 separates from the second mold 720, then the outer body mold 820 is slid to remove it from the inner body mold 810, and then the inner body mold 810 is opened from the split position to remove the prism.

[0087] Furthermore, in the molding apparatus for obtaining the prism 100B according to the third embodiment, compared to the molding apparatus 1000 shown in Figures 11 and 12, it is possible to use one that has recesses 723 not only on the first end 724 side adjacent to the first opposing surface 711, but also on the second end 726 side. To facilitate the removal of the prism 100B, it is also possible to make the inner body mold 810 a split mold, similar to the prism 100A. However, the removal of the prism 100 can also be made easier by making the inner body mold a split mold.

[0088] The prism and the method for manufacturing the same described herein have been explained above, but this disclosure is not limited thereto, and it will be understood that various modifications can be made by those skilled in the art without departing from the scope of the invention as defined in the claims below.

[0089] As described above, the prism of this disclosure is characterized in that, from the viewpoint of accurately mounting it to a predetermined location on an optical instrument, a rib portion 60 is provided between the ends of two adjacent surfaces among the first transmitting surface 10, the second transmitting surface 20, and the reflecting surface 30, protruding more than each of the two adjacent surfaces. In this regard, a rib portion 60 protruding more than each of the two adjacent surfaces may be provided between the second end 12 of the first transmitting surface 10 and the first end 21 of the second transmitting surface 20.

[0090] The present disclosure may take the following embodiments: <1> A prism comprising: a first light-transmitting surface; a second light-transmitting surface; and a reflective surface arranged in the optical path of the light between the first and second light-transmitting surfaces and inclined with respect to the first and second light-transmitting surfaces, wherein at least two of the first light-transmitting surface, the second light-transmitting surface and the reflective surface each have ends that are close to each other, and a rib portion is provided between the ends of the two close surfaces, protruding more than each of the two close surfaces. <2> The prism according to <1>, wherein the rib portion is provided between the end of the reflective surface and at least one end of the first light-transmitting surface and the second light-transmitting surface that is close to the end of the reflective surface. <3> The prism according to <1> or <2>, wherein a second rib portion is further provided between the end of the first light-transmitting surface and the end of the second light-transmitting surface that is close to the end of the first light-transmitting surface. <4> The prism according to any one of <1> to <3>, wherein the rib portion is provided between the end of the first transmissive surface and the end of the reflective surface adjacent to the end of the first transmissive surface, and the chamfered portion is provided between the end of the second transmissive surface and the end of the reflective surface adjacent to the end of the second transmissive surface. <5> The prism according to any one of <1> to <4>, wherein the rib portion is a positioning rib portion that defines the positional relationship with the component on which the prism is installed. <6> The prism according to any one of <1> to <5>, wherein the rib portion has a plurality of main surfaces, and at least one of the plurality of main surfaces is the installation surface with the component. <7> The prism according to <6>, wherein the installation surface is flat. <8> The prism according to any one of <1> to <7>, wherein the rib portion protrudes more than the first transmissive surface or the second transmissive surface in a direction perpendicular to the first transmissive surface or the second transmissive surface. <9> The prism according to any one of <1> to <8>, wherein the first transmitting surface or the second transmitting surface has a lens portion, and the rib portion protrudes in the thickness direction of the lens portion beyond the thickness of the lens portion. <10> The prism according to <9>, wherein the rib portion and the lens portion are separated by a predetermined distance. <11> The prism according to any one of <1> to <10>, wherein the angle of inclination between each of the first transmitting surface and the second transmitting surface and the reflective surface is 30° or more and 60° or less.<12> The prism according to any one of <1> to <11>, wherein the material of the prism is glass. <13> An optical instrument comprising the prism according to any one of <1> to <12>, and a component for supporting the prism. <14> A method for manufacturing a prism using a molding apparatus having a first mold and a second mold arranged in the pressing direction for forming a mold cavity, and a body mold arranged in a direction intersecting the pressing direction, comprising pressing a prism material in the pressing direction in the mold cavity, wherein the first mold and the second mold each have a first opposing surface and a second opposing surface that face each other and are capable of contacting the prism material, the first opposing surface includes an inclined surface inclined with respect to the second opposing surface, the second opposing surface has a recess at its end that is recessed in the pressing direction from its center, and the first opposing surface has an inclined surface that faces the center of the second opposing surface and an end surface that faces the end of the second opposing surface, is continuous with the inclined surface, and is located outside the inclined surface. <15> The method for manufacturing a prism according to <14>, wherein the second opposing surface has the recess at an end adjacent to the first opposing surface. <16> The method for manufacturing a prism according to <14> or <15>, wherein the spatial volume of the mold cavity is greater than or equal to the volume of the prism material.

[0091] The prisms disclosed herein can be used in optical communication devices and the like. For example, the prisms disclosed herein can be used for data center communications, EV communications in the mobility sector, HFT (high-speed trading) in financial institutions' trading systems, and communication systems for real-time feedback with remote locations. Cross-reference of related applications

[0092] This application claims priority under the Paris Convention based on Japanese Patent Application No. 2024-191005 (filing date: October 30, 2024, title of invention: "Prism and method for manufacturing the same"). All contents disclosed in said application are incorporated herein by reference.

[0093] 10 First transmitting surface 11 First end 12 Second end 13 Lens portion 14 Top of lens portion 20 Second transmitting surface 21 First end 22 Second end 30 Reflecting surface 31 First end 32 Second end 40 First end surface 50 Second end surface 60 Rib portion 61 First main surface (First main surface in contact with the upper surface of the first support portion 310 of the support component) 62 Second main surface (Second main surface in contact with one side surface that constitutes the space of the second support portion of the support component) 63 Third main surface (Third main surface in contact with the other side surface opposite to the one side surface that constitutes the space of the second support portion of the support component) 70 Second rib portion 80 Chamfered portion 90 Chamfered portion 100, 100A, 100B, 101, 102, 101A, 102A Prism 200, 200A Light source 300, 300A Support parts 310, 310A First support section 320, 320A Second support section 321 Space of the second support section 321A Stepped section of the second support section 330, 330A Third support section 400 Light receiving element 500, 500A Optical equipment 610 First heater section 620 Second heater section 710 Type 1 711 First opposing surface of Type 1 712 Inclined surface of Type 1 713 First end of the inclined surface of Type 1 714 Second end of the inclined surface of Type 1 715 End face of the first opposing surface of Type 1 716 End face of the first opposing surface of Type 1 720 Type 2 721 Second opposing surface of Type 2 722 Central part of the second opposing surface of Type 2 723 Recess located at the end of the second opposing surface of Type 2 724 725 First end of the second opposing surface of the second type 726 Second recess 726 Second end of the second opposing surface 800 Body mold 810 Inner body mold 820 Outer body mold 1000 Molding apparatus D Distance between the light source and the top of the lens part of the prism D1 Distance between the light source and the top of the lens part of the prism D2 Distance between the second transmitting surface of the prism and the light receiving element M Prism material P Pressure direction

Claims

1. A prism comprising: a first light-transmitting surface; a second light-transmitting surface; and a reflective surface positioned in the optical path of the light between the first and second light-transmitting surfaces and inclined with respect to the first and second light-transmitting surfaces, wherein two of the surfaces of the first, second and reflective surfaces each have adjacent ends, and a rib portion is provided between the adjacent ends of the two surfaces, protruding more than each of the two adjacent surfaces.

2. The prism according to claim 1, wherein the rib portion is provided between the end of the reflective surface and at least one end of the first transmissive surface and the second transmissive surface adjacent to the end of the reflective surface.

3. The prism according to claim 1 or 2, wherein a second rib portion is further provided between the end of the first transmissive surface and the end of the second transmissive surface adjacent to the end of the first transmissive surface.

4. The prism according to any one of claims 1 to 3, wherein the rib portion is provided between the end of the first transmissive surface and the end of the reflective surface adjacent to the end of the first transmissive surface, and the chamfered portion is provided between the end of the second transmissive surface and the end of the reflective surface adjacent to the end of the second transmissive surface.

5. The prism according to any one of claims 1 to 4, wherein the rib portion is a positioning rib portion that defines the positional relationship with the component on which the prism is installed.

6. The prism according to any one of claims 1 to 5, wherein the rib portion has a plurality of main surfaces, and at least one of the plurality of main surfaces is a mounting surface with the component.

7. The prism according to claim 6, wherein the mounting surface is flat.

8. The prism according to any one of claims 1 to 7, wherein the rib portion protrudes more than the first or second transmissive surface in a direction perpendicular to the first or second transmissive surface.

9. The prism according to any one of claims 1 to 8, wherein the first or second transmitting surface has a lens portion, and the rib portion protrudes in the thickness direction of the lens portion more than the thickness of the lens portion.

10. The prism according to claim 9, wherein the rib portion and the lens portion are separated by a predetermined distance.

11. The prism according to any one of claims 1 to 10, wherein the angle of inclination between each of the first and second transmission surfaces and the reflective surface is 30° or more and 60° or less.

12. The prism according to any one of claims 1 to 11, wherein the material of the prism is glass.

13. An optical instrument comprising a prism according to any one of claims 1 to 12, and a component for supporting the prism.

14. A method for manufacturing a prism using a molding apparatus having a first mold and a second mold arranged in the pressurizing direction for forming a mold cavity, and a body mold arranged in a direction intersecting the pressurizing direction, comprising pressing a prism material in the pressurizing direction in the mold cavity, wherein the first mold and the second mold each have a first opposing surface and a second opposing surface that face each other and are capable of contacting the prism material, the first opposing surface includes an inclined surface inclined with respect to the second opposing surface, the second opposing surface has a recess at its end that is recessed in the pressurizing direction from its center, and the first opposing surface has an inclined surface that faces the center of the second opposing surface and an end surface that faces the end of the second opposing surface, is continuous with the inclined surface, and is located outside the inclined surface.

15. The method for manufacturing a prism according to claim 14, wherein the second opposing surface has the recess at an end adjacent to the first opposing surface.

16. The method for manufacturing a prism according to claim 14 or 15, wherein the spatial volume of the mold cavity is greater than or equal to the volume of the prism material.

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