Grinding member of aspherical convex lens and grinding device of aspherical convex lens

Abstract

To provide a grinding member of an aspherical convex lens and a grinding device of an aspherical convex lens which can work an aspherical convex lens at low cost, while improving productivity and workability.SOLUTION: A grinding member 10 of an aspherical convex lens includes a grinding part 11 for grinding a ground surface 2a of an aspherical convex lens 2, wherein the grinding part 11 includes a central part flat surface 13 which is provided at the center of the grinding part 11 and has an approximately circular shape, and a ground surface 14 in which a concave surface is continuously and annularly provided on the outer periphery of the central part flat surface 13, and a circumference flat surface 15 that is annularly provided at an approximately same height position as the central part flat surface 13, on the outer periphery of the ground surface 14, and the ground surface 14 forms an optical functional surface by grinding the ground surface 2a of the aspherical convex lens 2 so as to be abutted thereon.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a grinding member for an aspherical convex lens and a grinding device for an aspherical convex lens, for grinding the surface to be ground of the aspherical convex lens to form an optically functional surface. [Background technology]

[0002] Conventionally, grinding, polishing, and other processing of optical lenses such as aspheric convex lenses have been performed by bringing the optical lens into contact with a grinding member such as a rotating grindstone. An example of a processing device that enables such processing is disclosed in Patent Document 1.

[0003] The processing device disclosed in Patent Document 1 polishes an optical lens by bringing it into contact with the polishing surface of a rotating polishing dish, and is configured to include a first oscillation axis that supports an upper shaft to which the optical lens is fixed and oscillates around the center of curvature of the polishing surface of the polishing dish, a linear axis that supports the first oscillation axis and is capable of linear displacement in a direction intersecting the oscillation surface of the first oscillation axis, and a second oscillation axis on which a lower shaft that supports the polishing dish is placed and oscillates around the center of curvature of the polishing dish. As a result, the polishing device of Patent Document 1 makes it possible to polish optical elements with various external specifications with high precision using a single polishing device.

[0004] However, the polishing apparatus disclosed in Patent Document 1 is generally expensive and requires a long processing time, so that even though it is suitable for high value-added products such as aspheric convex lenses, there is a problem in that the equipment costs are too high. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP2009-113162A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a grinding member for an aspherical convex lens and a grinding device for an aspherical convex lens that are capable of machining an aspherical convex lens at low cost while improving productivity and operability. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the grinding member for an aspherical convex lens of the present invention is a grinding member for an aspherical convex lens having a grinding portion for grinding the grinding surface of an aspherical convex lens, wherein the grinding portion has a substantially circular central flat surface provided in the center of the grinding portion, a grinding surface having a continuous concave curved surface provided in an annular shape on the outer periphery of the central flat surface, and a peripheral flat surface provided in an annular shape on the outer periphery of the grinding surface at a position substantially the same height as the central flat surface, and the grinding surface forms an optically functional surface by abutting against and grinding the grinding surface of the aspherical convex lens.

[0008] According to the above-mentioned configuration, the grinding surface in the grinding part is configured by providing a continuous concave curved surface in an annular shape on the outer periphery of the central flat surface. Therefore, the grinding surface is brought into contact with the grinding surface of the aspherical convex lens, and the grinding surface of the aspherical convex lens can be ground to form an optically functional surface by simply rotating the grinding part around its central axis. In other words, with the grinding member of the above-mentioned configuration, it is possible to manufacture a good aspherical convex lens by suppressing the equipment cost while improving the productivity and workability without using an expensive grinding device.

[0009] In the above-described configuration, it is preferable that the central flat surface and the peripheral flat surface are ground in contact with the outer periphery of the aspherical convex lens to form a non-optically functional surface on the outer periphery of the optically functional surface.

[0010] In the above-mentioned configuration, it is preferable that, of the central flat surface, the grinding surface and the peripheral flat surface, at least the grinding surface is provided with an abrasive layer containing diamond abrasive grains.

[0011] In order to solve the above-mentioned problems, the present invention provides an aspherical convex lens grinding device comprising: a grinding member for the aspherical convex lens; a grinding member holding section which holds the grinding member so that a grinding surface of the grinding section faces the aspherical convex lens and rotates the grinding member around its central axis; and an aspherical convex lens holding section which holds the aspherical convex lens so that a surface to be ground faces the grinding member and rotates the aspherical convex lens around its central axis, The grinding member holding part and the aspherical convex lens holding part abut the grinding surface of the aspherical convex lens against the grinding surface of the grinding part with the central axis of the grinding member and the central axis of the aspherical convex lens parallel to each other, and further, the grinding member holding part rotates the grinding member around its central axis, and the aspherical convex lens holding part rotates the aspherical convex lens around its central axis, thereby grinding the grinding surface with the grinding surface to form an optically functional surface.

[0012] According to the above configuration, the grinding member holding part and the aspherical convex lens holding part hold the grinding member and the aspherical convex lens, respectively, so that the grinding surface of the grinding member and the grinding surface of the aspherical convex lens face each other. In addition, the grinding member holding part and the aspherical convex lens holding part abut the grinding surface of the aspherical convex lens against the grinding surface of the grinding part, with the central axis of the grinding member and the central axis of the aspherical convex lens being parallel. Then, the grinding member holding part can grind the grinding surface of the aspherical convex lens to form an optically functional surface by simply rotating the grinding member around its central axis. In other words, with the grinding device of the above configuration, it is possible to manufacture a good aspherical convex lens while suppressing the device cost and improving productivity and workability without using an expensive grinding device.

[0013] In the above configuration, it is preferable that the device further includes a grinding fluid supply unit that supplies grinding fluid to the grinding surface of the grinding member held in the grinding member holding unit, the grinding member holding unit holds the grinding member so that the central axis of the grinding member is parallel to a horizontal plane, and the aspherical convex lens holding unit holds the aspherical convex lens so that the central axis of the aspherical convex lens is parallel to a horizontal plane. Effect of the Invention

[0014] The present invention uses a grinding unit for grinding the grinding surface of an aspherical convex lens, which has a grinding surface in which a concave curved surface is continuously provided in an annular shape on the outer periphery of a central flat surface. As a result, in the present invention, the grinding surface is brought into contact with the grinding surface of the aspherical convex lens, and the grinding surface of the aspherical convex lens can be ground to form an optically functional surface simply by rotating the grinding unit around its central axis. In other words, the present invention can provide a grinding member and a grinding device that can manufacture an aspherical convex lens while suppressing equipment costs and improving productivity and workability without using an expensive grinding device. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic diagram illustrating a schematic configuration of a grinding device according to an embodiment of the present invention. [Diagram 2] FIG. 2(a) is a perspective view showing a schematic diagram of a grinding member according to an embodiment of the present invention, FIG. 2(b) is a plan view of the grinding member seen from above, and FIG. 2(c) is a bottom view of the grinding member seen from below. [Diagram 3] 1 is a schematic cross-sectional view illustrating an outline of a grinding member according to an embodiment of the present invention. [Figure 4] 1 is a perspective view illustrating a schematic view of an aspherical convex lens holding portion capable of holding an aspherical convex lens. FIG. [Diagram 5] 1 is a schematic explanatory diagram showing a state in which an aspheric convex lens is ground using a grinding device according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] (Grinding Equipment) A grinding device according to an embodiment of the present invention will be described below with reference to the drawings. However, parts that are not necessary for the description will be omitted, and some parts are illustrated enlarged or reduced in size to facilitate the description.

[0017] The grinding apparatus 1 of this embodiment is an apparatus for grinding the surface to be ground of an aspheric convex lens. 1, the grinding device 1 includes at least a grinding member 10 for grinding an aspherical convex lens 2, a grinding member holding unit 20 for holding the grinding member 10, an aspherical convex lens holding unit 30 for holding the aspherical convex lens 2, and a grinding fluid supply unit 40. Fig. 1 is a schematic diagram showing a general configuration of the grinding device 1 of the present embodiment.

[0018] 1 to 3, the grinding member 10 includes a grinding portion 11 for grinding the aspheric convex lens 2, and a protrusion 12 for connection to a grinding member holder 20. Fig. 2(a) is a perspective view showing the grinding member 10 of this embodiment, Fig. 2(b) is a plan view of the grinding member 10 seen from above, and Fig. 2(c) is a bottom view of the grinding member 10 seen from below. Fig. 3 is a schematic cross-sectional view showing the grinding member 10 of this embodiment.

[0019] The grinding portion 11 has a thick disk-like overall shape. One surface (upper surface) of the grinding portion 11 is provided with a substantially circular central flat surface 13 provided in the center of the grinding portion 11, a grinding surface 14 provided on the outer periphery of the central flat surface 13, and a peripheral flat surface 15 provided in an annular shape on the outer periphery of the grinding surface 14. The other surface (lower surface) of the grinding portion 11 is a flat surface 16 as shown in Figs. 2(c) and 3. The thickness of the grinding portion 11 is not particularly limited and can be set appropriately.

[0020] The central flat surface 13 is circular in plan view. When grinding the grinding surface 2a of the aspherical convex lens 2, the central flat surface 13 can be ground in contact with the outer peripheral edge portion 2b of the aspherical convex lens 2 to form a non-optically functional surface. The area of ​​the central flat surface 13 is not particularly limited, and can be appropriately set according to the grinding portion 11 and the size of the aspherical convex lens 2 to be ground (more specifically, the size of the grinding surface 2a of the aspherical convex lens 2). In this specification, the "non-optically functional surface" means a surface that does not satisfy the optical characteristics required of an aspherical convex lens and does not participate in the optical function. In this embodiment, the outer peripheral edge portion 2b corresponds to the non-optically functional surface of the present invention when the outer peripheral edge portion 2b is flat, and even when it is not flat, when the light beam does not pass through the outer peripheral edge portion 2b during use.

[0021] The grinding surface 14 is provided in an annular shape on the outer periphery of the central flat surface 13. The grinding surface 14 has a concave curved cross section in the thickness direction of the grinding portion 11, as shown in FIG. 3. By making the cross section of the grinding surface 14 a concave curved surface, when the aspherical convex lens 2 to be ground is brought into contact with the grinding surface 14, the grinding surface 14 can be brought into contact with the meridian passing through the apex of the grinding surface (convex surface) 2a of the aspherical convex lens 2. That is, the grinding surface 14 of this embodiment does not come into contact with the grinding surface 2a of the aspherical convex lens 2 by point contact. Therefore, compared with the conventional grinding device that performs grinding by point contact, the grinding surface 2a of the aspherical convex lens 2 can be easily ground to form an optically functional surface. The depth D and width W of the grinding surface 14 shown in FIG. 3 are not particularly limited and can be appropriately set according to the size of the aspherical convex lens 2 to be ground. In this specification, the term "optically functional surface" refers to a surface that has the optical properties required of an aspheric convex lens.

[0022] The peripheral flat surface 15 is provided in an annular shape on the outer periphery of the grinding surface 14. When the grinding surface 2a of the aspherical convex lens 2 is ground, the peripheral flat surface 15 comes into contact with the outer periphery 2b of the aspherical convex lens 2 and is ground to form a non-optically functional surface. Furthermore, the height position of the peripheral flat surface 15 is substantially the same as that of the central flat surface 13, as shown in FIG. 3. This makes it possible to equalize the pressure with which the outer periphery 2b of the aspherical convex lens 2 comes into contact with the central flat surface 13 and the peripheral flat surface 15 when the grinding surface 2a of the aspherical convex lens 2 is brought into contact with the grinding surface 14.

[0023] In this embodiment, the surfaces of the central flat surface 13, the grinding surface 14, and the peripheral flat surface 15 are provided with an abrasive layer (not shown) containing diamond abrasive grains. By providing the abrasive layer, the grinding time of the aspheric convex lens 2 can be shortened and the productivity of the grinding process can be improved. The thickness of the abrasive layer is preferably uniform within the central flat surface 13, the grinding surface 14, and the peripheral flat surface 15. In addition, it is preferable that the diamond abrasive grains are dispersed and mixed in the abrasive layer. The average particle size of the diamond abrasive grains is not particularly limited and can be set appropriately as necessary. In the present invention, the abrasive layer may be provided at least on the surface of the grinding surface 14.

[0024] As shown in Figs. 1, 2(c) and 3, the protruding portion 12 is provided at the center of the flat surface 16 of the grinding portion 11 so as to protrude in a direction perpendicular to the flat surface 16. The overall shape of the protruding portion 12 is cylindrical, and the inside of the protruding portion 12 is provided with a female screw portion 17 that enables screwing with the grinding member holding portion 20. This allows the grinding member 10 to be fixed to the grinding member holding portion 20 by screwing it into the grinding member holding portion 20 having a male screw portion (details will be described later). In addition, a flat portion 18 is provided at an arbitrary position on the side peripheral surface of the protruding portion 12. This allows the grinding member 10 fixed to the grinding member holding portion 20 to be removed using a known clamping member such as pliers, by clamping the clamping member so as to include the flat portion 18, the flat portion 18 can function as an anti-slip member.

[0025] The grinding member holding part 20 has a male screw portion 21 at its tip. The male screw portion 21 can be screwed into the female screw portion 17 provided on the protruding portion 12 of the grinding member 10. The grinding member 10 can be fixed to the grinding member holding part 20 by screwing the male screw portion 21 into the female screw portion 17. The grinding member holding part 20 fixes the grinding member 10 so that the central axis 51 of the held grinding member 10 is parallel to a horizontal plane. The grinding member holding part 20 is electrically connected to a rotation drive unit (not shown), and the rotation of the grinding member holding part 20 causes the held grinding member 10 to rotate around its central axis 51.

[0026] As shown in FIG. 4, the aspherical convex lens holding part 30 is hollow inside, and can hold the aspherical convex lens 2 at its upper end. FIG. 4 is a perspective view that shows a schematic representation of the aspherical convex lens holding part 30 capable of holding the aspherical convex lens 2. At the upper end, a mounting part 31 capable of holding the aspherical convex lens 2 is provided so that the grinding surface 2a of the aspherical convex lens 2 is exposed. The mounting surface 31a of the mounting part 31 is provided with a step so that the height position is lower than the peripheral part 31b. This allows the mounting part 31 to mount the aspherical convex lens 2 so as to be fitted into it. In addition, a cutout part 34 is provided in a part of the peripheral part 31b. The cutout part 34 extends linearly at an arbitrary distance toward the lower end on the side wall part 35 of the aspherical convex lens holding part 30. This allows the peripheral portion 31b to be expanded in diameter according to the size of the aspherical convex lens 2 when the aspherical convex lens 2 is fitted and placed on the mounting portion 31. Furthermore, a pair of through holes 36 penetrating the aspherical convex lens holding portion 30 is provided in the side wall portion 35 of the aspherical convex lens holding portion 30. For example, a bolt is inserted through the side wall portion 35 via the pair of through holes 36, and the penetrating bolt is fastened with a nut from the opposite side, thereby making it possible to reduce the diameter of the peripheral portion 31b. As a result, the aspherical convex lens 2 is fixed at the peripheral portion 31b, and it is possible to prevent the lens 2 from coming off the mounting portion 31.

[0027] The aspherical convex lens holding unit 30 fixes the aspherical convex lens 2 so that the central axis 52 of the held aspherical convex lens 2 is parallel to the horizontal plane. Furthermore, the aspherical convex lens holding unit 30 is electrically connected to another rotation drive unit (not shown), and the aspherical convex lens holding unit 30 rotates to rotate the held aspherical convex lens 2 around its central axis 52 (see FIG. 1). The aspherical convex lens holding unit 30 is disposed so that the grinding surface 2a of the held aspherical convex lens 2 faces the grinding surface 14 of the grinding member 10. The aspherical convex lens holding unit 30 presses the held aspherical convex lens 2 against the grinding surface 14 so that the held aspherical convex lens 2 is ground in a state of being pressed against (in contact with) the grinding surface 14 of the grinding member 10.

[0028] As a method for pressing (contacting) the aspherical convex lens 2 against the grinding surface 14 of the grinding member 10, in addition to the case where the aspherical convex lens holding part 30 presses the aspherical convex lens 2 against the grinding surface 14, the grinding member holding part 20 may press the grinding surface 14 of the grinding member 10 it holds against the aspherical convex lens 2. Alternatively, the grinding member holding part 20 and the aspherical convex lens holding part 30 may both press the grinding surface 14 of the grinding member 10 against the aspherical convex lens 2 against each other.

[0029] The grinding fluid supply unit 40 supplies a grinding fluid between the grinding member 10 and the aspherical convex lens 2 when the grinding member 10 grinds the aspherical convex lens 2. The grinding fluid supply unit 40 includes a grinding fluid storage unit (not shown) and a grinding fluid supply pipe 41. The grinding fluid storage unit stores the grinding fluid therein. The grinding fluid storage unit is connected to the grinding fluid supply pipe 41 for supplying the grinding fluid between the grinding member 10 and the aspherical convex lens 2. Furthermore, an opening / closing valve (not shown) may be provided in the path of the grinding fluid supply pipe 41. The opening and closing of the opening / closing valve may be controlled. In this case, when the opening / closing valve is opened by an operation command, the grinding fluid is pumped through the grinding fluid supply pipe 41.

[0030] (Grinding method) Next, a method for grinding an aspherical convex lens 2 using the grinding device 1 of this embodiment will be described with reference to Fig. 5. Fig. 5 is a schematic explanatory diagram showing how an aspherical convex lens 2 is ground.

[0031] As shown in FIG. 5, the aspherical convex lens 2 before grinding is held by the aspherical convex lens holding part 30. The aspherical convex lens 2 is held so that its central axis 52 is parallel to a horizontal plane. The aspherical convex lens holding part 30 is disposed so that the grinding surface 2a of the aspherical convex lens 2 faces the grinding surface 14 of the grinding member 10. Next, the aspherical convex lens holding part 30 is rotated while holding the aspherical convex lens 2. As a result, the aspherical convex lens 2 held by the aspherical convex lens holding part 30 is rotated around the central axis 52. The rotation speed of the aspherical convex lens 2 is not particularly limited and can be set appropriately.

[0032] The grinding member 10 is held by the grinding member holding part 20. The grinding member 10 is held so that its central axis 51 is parallel to a horizontal plane. The grinding member holding part 20 is disposed so that the grinding surface 14 of the grinding member 10 faces the grinding surface 2a of the aspheric convex lens 2. Next, the grinding member holding part 20 is rotated while the grinding member 10 is fixed. This causes the grinding member 10 held by the grinding member holding part 20 to rotate around the central axis 51. The rotation speed of the grinding member 10 is not particularly limited and can be set appropriately.

[0033] The rotation speed of the aspherical convex lens 2 and the rotation speed of the grinding member 10 can be set appropriately according to the needs. For example, the rotation speed of the aspherical convex lens 2 and the rotation speed of the grinding member 10 may be the same or different. The rotation speed of the grinding member 10 may be changed depending on the area of ​​the grinding surface 2a of the aspherical convex lens 2. More specifically, when the area of ​​the grinding surface 2a is small, the rotation speed of the grinding member 10 may be slowed down, and when the area of ​​the grinding surface 2a is large, the rotation speed of the grinding member 10 may be fastened. The rotation directions of the aspherical convex lens 2 and the grinding member 10 may be the same or different.

[0034] Furthermore, while the aspherical convex lens 2 and the grinding member 10 are rotated, the grinding surface 2a is brought into contact with the grinding surface 14 of the grinding member 10, and the grinding surface 2a is ground. At this time, a grinding fluid is supplied between the grinding surface 2a of the aspherical convex lens 2 and the grinding surface 14 of the grinding member 10 from the grinding fluid supply pipe 41 of the grinding fluid supply unit 40. The grinding surface 2a of the aspherical convex lens 2 comes into contact with the grinding surface 14 on the meridian passing through its apex, but since the aspherical convex lens 2 itself rotates around the central axis 52, the entire surface of the grinding surface 2a can be brought into contact with the grinding surface 14. Therefore, in the grinding device 1 of this embodiment, it is not necessary to appropriately adjust the grinding area of ​​the grinding surface 2a by, for example, tilting the grinding unit 11 at an arbitrary angle with respect to the aspherical convex lens 2. The outer peripheral edge 2b of the aspherical convex lens 2 is ground in contact with the central flat surface 13 and the peripheral flat surface 15 of the grinding unit 11. This makes it possible to form an optically functional surface on the ground surface 2a of the aspherical convex lens 2.

[0035] As described above, the grinding method using the grinding device 1 of this embodiment makes it possible to easily form an optically functional surface by simply bringing the grinding part 11 into contact with the grinding surface 2a of the aspherical convex lens 2. Therefore, the grinding method using the grinding device 1 of this embodiment makes it possible to grind a good aspherical convex lens 2 while suppressing equipment costs and improving productivity and workability without using an expensive grinding device. [Explanation of symbols]

[0036] 1: Grinding device 2: Aspheric convex lens 2a: Surface to be ground 2b: Outer periphery 10: Grinding material 11: Grinding section 12:Protrusion 13: Central flat surface 14: Grinding surface 15: Flat peripheral surface 16:Flat surface 17: Female thread 18: Flat part 20: Grinding member holding part 21: Male thread 30: Aspheric convex lens holder 40: Grinding fluid supply unit 41: Grinding fluid supply pipe 51: Central axis 52: Central axis

Claims

1. A grinding member for an aspheric convex lens, comprising a grinding portion for grinding a surface of the aspheric convex lens, The grinding unit includes: A generally circular central flat surface provided at the center of the grinding portion; a grinding surface having a continuous concave curved surface formed in an annular shape on an outer periphery of the central flat surface; a peripheral flat surface provided annularly on the outer periphery of the grinding surface at substantially the same height as the central flat surface, The grinding surface of the aspherical convex lens is brought into contact with the surface to be ground of the aspherical convex lens and ground to form an optically functional surface.

2. 2. The grinding member for an aspheric convex lens according to claim 1, wherein the central flat surface and the peripheral flat surface are ground in contact with an outer peripheral edge portion of the aspheric convex lens to form a non-optically functional surface on the outer periphery of the optically functional surface.

3. 2. The grinding member for an aspheric convex lens according to claim 1, wherein at least the grinding surface out of the central flat surface, the grinding surface and the peripheral flat surface is provided with an abrasive layer containing diamond abrasive grains.

4. A grinding member for the aspheric convex lens according to any one of claims 1 to 3; a grinding member holding section that holds the grinding member so that a grinding surface of the grinding section faces the aspherical convex lens and rotates the grinding member around its central axis; an aspherical convex lens holding section that holds the aspherical convex lens so that the surface to be ground faces the grinding member and rotates the aspherical convex lens around its central axis, the grinding member holding portion and the aspherical convex lens holding portion bring the grinding surface of the aspherical convex lens into contact with the grinding surface of the grinding portion in a state in which the central axis of the grinding member and the central axis of the aspherical convex lens are parallel to each other; Furthermore, the grinding member holding unit rotates the grinding member about its central axis, and the aspherical convex lens holding unit rotates the aspherical convex lens about its central axis, thereby grinding the grinding surface with the grinding surface to form an optically functional surface.

5. a grinding fluid supply unit that supplies a grinding fluid to the grinding surface of the grinding member held by the grinding member holding unit; the grinding member holding portion holds the grinding member such that a central axis of the grinding member is parallel to a horizontal plane; 5. The grinding device for an aspherical convex lens according to claim 4, wherein the aspherical convex lens holding portion holds the aspherical convex lens such that a central axis of the aspherical convex lens is parallel to a horizontal plane.

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