JP2006289692A - Manufacturing method of mirror surface component, manufacturing method of optical element and optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element manufacturing technique capable of manufacturing an optical element of high precision reduced in the eccentricity quantity of its optical axis. <P>SOLUTION: The resin molding of a temporary optical element is performed using a temporary mirror surface component before correction processing (step 101), the shift of the optical axis of the optical element is measured actually (steps 102, 103 and 104), the position of the optical axis of the temporary mirror surface component used in molding is measured actually (step 105), correction data for shifting the position of the optical axis of the temporary mirror surface component actually measured in the step 105 in the direction offsetting the shift of the position of the optical axis of the temporary optical element actually measured in the step 104 is formed (step 106) to perform the correction processing of the temporary mirror surface component (step 107) and the optical element becoming a product is molded using the corrected mirror surface component (step 108). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a mirror piece manufacturing technique, an optical element manufacturing technique, and an optical element, and more particularly to a technique effective when applied to a resin molding technique for an optical element.

  Examples of optical elements used in optical equipment include lenses and prisms having optical functional surfaces such as aspherical surfaces, spherical surfaces, and free-form surfaces. Conventionally, such an optical element is generally manufactured using a technique such as injection molding using a thermoplastic material. In manufacturing the optical elements, it is necessary to reproduce the positional relationship of the optical surfaces of these optical elements as designed values. Here, a mold is used to manufacture the optical element. The mold has a mirror piece, and this mirror piece corresponds to the optical surface of the optical element. For this reason, very advanced machining and assembly techniques are required for positioning the mirror piece.

  As described above, when molding an optical element, a method of providing a mirror piece for each optical surface and individually transferring each optical surface is generally used. Therefore, in order to keep the relative positional deviation (for example, the optical axis deviation) between the optical surfaces within the dimensional tolerance, the fitting margin with the core into which the mirror piece is incorporated is extremely small, or each of the components including the mirror piece is included. It is necessary to tighten the dimensional accuracy of mold parts. However, even if the dimensional accuracy of each mold part is extremely strict, a machining error occurs in each part. Therefore, since processing errors are accumulated, there is a limit to reducing the deviation from the design value in each mirror piece.

  As a countermeasure, Patent Document 1 discloses a technique in which a wedge or an adjustment bolt for adjusting the position of the mirror surface piece with respect to the mold base is provided between the mold base and the mirror surface piece. By doing in this way, position adjustment of a mirror surface piece is attained, and a mirror surface piece can be assembled | attached with high precision. That is, in Patent Document 1, the positional deviation of the mirror piece is measured by the optical axis measuring device, and the deviation amount of the mirror piece is adjusted by the wedge or the adjusting bolt.

On the other hand, Patent Document 2 discloses a technique for correcting a mirror piece. In Patent Document 2, first, the amount of deviation from the design value of the shape (optical surface) of a temporarily molded lens is obtained. Then, the amount of deviation is fed back to the processing value of the mirror surface piece to perform correction processing. By doing so, the deviation from the design value of the mirror piece is corrected.
Japanese Patent Laid-Open No. 11-77763 JP 2004-66612 A

  However, in the technique of Patent Document 1, since it is necessary to provide a position adjusting means in the mold, the mold becomes large. Moreover, in the technique of patent document 1, since adjustment scissors are provided, the air layer which has a heat insulation effect generate | occur | produces in a metal mold | die, and there exists a possibility that the temperature distribution in a metal mold | die before and behind adjustment may change. Therefore, it is difficult to stably obtain the quality of the molded product.

  Moreover, in patent document 2, only the deviation | shift amount from the design value in the optical surface at the time of temporary shaping is only fed back to the processing value of a mirror surface piece. Therefore, the position of the center (in the case of a rotationally symmetric optical element, the optical axis corresponds) in the plane of the mirror piece itself is not grasped. Therefore, in the actual processing of the mirror surface piece, the mirror surface may not be produced according to the processing value. The reason will be described. When attaching the mirror piece to the processing machine, there is an attachment error. Further, when holding the mirror piece on the processing machine, there is a processing error in the holding jig. However, these errors cannot be obtained from optical surface measurements. For this reason, even if the mirror surface piece is corrected based only on the measurement result of the optical surface, an error occurs when the correction piece is attached to the mold body. Then, this error becomes a deviation of the center of the optical surface.

  The present invention has been made in view of the above problems, and an object of the present invention is to manufacture a high-precision optical element with a small deviation from a design value, for example, a high-precision optical element with a small amount of eccentricity of the optical axis. An object of the present invention is to provide a technique for producing a mirror piece that can be used.

  Another object of the present invention is a technique for producing a mirror piece that can manufacture a high-precision optical element with little deviation from a design value even if the optical surface is an optical surface that does not have a rotational symmetry axis. Is to provide.

  Another object of the present invention is a technique for manufacturing an optical element capable of manufacturing a high-precision optical element with a small deviation from a design value, for example, a high-precision optical element with a small amount of eccentricity of the optical axis. It is to provide.

  Another object of the present invention is to manufacture an optical element capable of manufacturing a high-precision optical element with little deviation from the design value even if the optical surface is an optical surface having no rotational symmetry axis. To provide technology.

A first aspect of the present invention is a step of forming a temporary optical element using a temporary mirror surface piece,
Measuring the shape of the optical surface of the temporary optical element to obtain a reference axis position in the measured shape;
Obtaining a position of a reference axis position in the design shape of the temporary optical element;
Calculating a relative shift amount between a reference axis position in the measurement shape and a reference axis position in the design shape;
Measuring the shape of the mirror surface of the temporary mirror surface piece, and calculating a reference axis position in the measurement shape of the mirror surface;
Processing the mirror surface of the temporary mirror surface piece so as to correct the reference axis position of the temporary mirror surface piece based on the amount of deviation, and producing a mirror surface piece;
A method of manufacturing a mirror piece having the above is provided.

According to a second aspect of the present invention, in the method for manufacturing a specular piece according to the first aspect,
In producing the temporary mirror surface piece, a method of producing a mirror surface piece is provided which includes a step of relatively moving the mirror surface of the temporary mirror surface piece and a processing tool in two directions orthogonal to each other.

According to a third aspect of the present invention, in the method for manufacturing a specular piece according to the first aspect or the second aspect,
In the step of producing the mirror surface piece, a method of producing a mirror surface piece is provided in which the mirror surface of the temporary mirror surface piece and the machining tool are relatively moved in two orthogonal directions.

According to a fourth aspect of the present invention, in the method for manufacturing a specular piece according to any one of the first to third aspects,
The step of obtaining the reference axis position in the measurement shape and the step of obtaining the position of the reference axis position in the design shape provide a method for producing a mirror piece that is performed based on the position of a reference object provided in the temporary optical element. .

According to a fifth aspect of the present invention, in the method for manufacturing a specular piece according to the fourth aspect,
The reference is one,
Provided is a specular piece manufacturing method for calculating the position of the reference axis based on the one reference object for each of the plurality of optical surfaces.

According to a sixth aspect of the present invention, in the method for manufacturing a specular piece according to the fourth aspect,
The reference object is the same as the number of the optical surfaces,
Provided is a mirror piece manufacturing method for calculating the position of the reference axis based on each reference object for each of the plurality of optical surfaces.

According to a seventh aspect of the present invention, in the method for manufacturing a specular piece according to the fourth aspect,
The reference object is less than the number of the optical surfaces,
Provided is a specular piece manufacturing method for calculating the position of the reference axis based on a common reference object for at least two of the plurality of optical surfaces.

An eighth aspect of the present invention is an optical element manufacturing method for forming an optical element using a mirror piece,
An optical element manufacturing method using a specular piece manufactured by the method for manufacturing a specular piece according to any one of the first aspect to the seventh aspect is provided.

A ninth aspect of the present invention provides an optical element manufactured by using the method for manufacturing an optical element described in the eighth aspect.
A tenth aspect of the present invention is the optical element according to the ninth aspect,
The optical element provides an optical element which is a prism having a curved surface shape having no rotational symmetry axis on at least one optical surface.

  According to the present invention, a high-precision optical element with a small deviation from the design value, for example, a high-precision optical element with a small amount of eccentricity of the optical axis, and a mirror piece capable of manufacturing such an optical element are provided. Can be obtained.

  According to the present invention, even if the optical surface is an optical surface that does not have a rotationally symmetric axis, it is possible to manufacture a high-precision optical element with little deviation from the design value, and a mirror surface on which such an optical element can be manufactured. It becomes possible to obtain a piece.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
FIG. 1 is a flowchart showing an example of a method for manufacturing a specular piece and an optical element manufacturing method according to an embodiment of the present invention, and FIG. 2 shows molding used in the optical element manufacturing method of the present embodiment. FIG. 3 is a cross-sectional view showing an example of the configuration of the apparatus, FIG. 3 is a perspective view showing an example of the configuration of the mirror surface processing apparatus used in the method for manufacturing the mirror surface piece of the present embodiment, and FIG. 4 is a diagram of the mirror surface piece of the present embodiment. It is a conceptual diagram which shows an example of a structure of the non-contact three-dimensional measuring machine used for the manufacturing method and the manufacturing method of an optical element.

  As illustrated in FIG. 2, the molding apparatus 10 used in the present embodiment includes a fixed mold plate 12 and a movable mold plate 14. Here, the stationary template 12 is supported by the stationary plate 11. Moreover, the movable mold 14 is supported by the movable plate 13 via the spacer block 13c.

  A plurality of sets of specular pieces 15 and specular pieces 16 are arranged on the opposing surfaces of the fixed mold plate 12 and the movable mold plate 14. The mirror surface piece 15 and the mirror surface piece 16 are arranged in a posture in which the molding surface 15a and the molding surface 16a face each other. Then, the fixed mold plate 12 and the movable mold plate 14 come into close contact with each other so that a mold clamping state is obtained. In this clamping state, the cavity 17 is formed by the molding surface 15a and the molding surface 16a.

  A sprue 19 is provided at the center of the fixed template 12 so as to penetrate in the thickness direction. A plurality of runners 18 are provided radially on the opposed surfaces of the fixed mold plate 12 and the movable mold plate 14 with the open end of the sprue 19 as the center. The tip of each runner 18 communicates with each of the cavities 17.

  In the mold clamping state, thermoplastic resin flowing from the outside is press-fitted into the individual cavities 17 through the sprue 19 and the runner 18. By doing in this way, resin is filled in the cavity 17. And the aspherical lens 50 which has the optical surface 51a and the optical surface 51b with this filled resin is manufactured. Here, the optical surface 51a and the optical surface 51b are obtained by transferring the surface shapes of the molding surface 15a and the molding surface 16a, respectively. Therefore, the surface shapes of the optical surface 51a and the optical surface 51b are defined by the surface shapes of the molding surface 15a and the molding surface 16a.

  Further, at the time of mold release for separating the fixed mold 12 and the movable mold 14, the protrusion pin 13 a protrudes from the movable mold 14. The resin filled in the runner 18 from the movable mold plate 14 side is separated from the movable mold plate 14 and the molding surface 16a by the protrusion of the protrusion pin 13a.

  As illustrated in FIG. 3, the specular piece processing apparatus 20 in the present embodiment includes an XY stage 21, a Z-axis column 22, a tool arm 23, a cutting tool 24, and a three-dimensional processing controller 25.

  A processing jig 31 is placed on the XY stage 21. A workpiece is placed on the processing jig 31. Here, the workpiece is the mirror piece 15 or the mirror piece 16. The workpiece is positioned and fixed in a predetermined posture by a fixing screw 31a. Then, the workpiece is moved in the horizontal plane by the XY stage 21. A cutting tool 24 is supported on the Z-axis column 22 via a tool arm 23. The cutting tool 24 in the height direction (Z-axis direction) is moved up and down by the Z-axis column 22.

  Then, the three-dimensional processing controller 25 drives the XY stage 21 and the Z-axis column 22 based on the design data 26. By this driving, the workpiece is moved on the XY stage 21 in the X and Y directions perpendicular to each other in the horizontal plane. On the other hand, in the Z-axis column 22, the cutting tool 24 is moved up and down. By combining such operations, for example, the tip (face) portion of the cutting tool 24 can be moved in a zigzag manner like the machining locus 24a. By doing in this way, the aspherical molding surface 15a (molding surface 16a) is formed in the workpiece.

  Note that the workpiece is accurately positioned with respect to the XY stage 21 by the processing jig 31. That is, the processing jig 31 is fixed at a fixed position with respect to the XY stage 21, and the workpiece is fixed at a fixed position with respect to the processing jig 31. By doing so, the workpiece is accurately fixed to the coordinate system unique to the mirror surface piece processing apparatus 20. In FIG. 3, the workpiece is moved in the X direction or the Y direction by the XY stage 21. However, it is not limited to such a configuration. For example, the workpiece may be fixed and the Z-axis column 22 may be moved in the X direction or the Y direction. Such a configuration may be adopted in the mirror surface piece processing apparatus 20.

  Next, a non-contact three-dimensional measuring machine will be described. FIG. 4 is an example of a non-contact three-dimensional measuring machine. The non-contact three-dimensional measuring machine 40 is, for example, an autofocus type non-contact three-dimensional measuring machine. The non-contact three-dimensional measuring machine 40 includes a laser 41 that emits a laser beam 41a, a predetermined optical system, and a moving mechanism 46. The predetermined optical system includes a mirror 42, a mirror 43, a mirror 44, and an objective lens 45. Among these, the mirror 42 guides the laser light 41 a to the object to be measured and guides the reflected light to the optical position detection device 47. The moving mechanism 46 controls the focal position of the objective lens 45 with respect to the object to be measured.

  In this embodiment, the non-contact three-dimensional measuring machine 40 includes an aspheric lens 50 molded as a temporary optical element, a molding surface 15a of the mirror piece 15 used for molding the aspheric lens 50, and the mirror piece 16. Used for measurement of the molding surface 16a. In this case, in the measurement of the aspheric lens 50, a measurement jig 49 is used as illustrated in FIG.

  Further, in the measurement of the molding surface 15a and the molding surface 16a, as illustrated in FIG. 5, the same processing jig 31 as that used during processing is used. That is, the state in which the mirror piece 15 and the mirror piece 16 are fixed by the processing jig 31 is preferably equivalent to the state in which the mirror piece 15 and the mirror piece 16 are fixed to the fixed mold 12 and the movable mold 14. In the present embodiment, the outer peripheral surfaces of the mirror piece 15 and the mirror piece 16 are used as positioning reference portions. Then, using this processing jig 31, the position of the optical axis A0 is obtained by measuring the optical axis A0 with a non-contact three-dimensional measuring device 40 as shown in FIG. Then, the position of the optical axis A0 is equivalent to the position of the optical axis when the mirror piece 15 and the mirror piece 16 are attached to the fixed mold plate 12 and the movable mold plate 14.

  The laser light 41 a emitted from the laser 41 enters the objective lens 45 through the mirror 43 and the mirror 42. The incident laser light 41a is condensed toward the focal plane of the objective lens 45 and irradiated onto the measurement surface of the test object. The laser beam 41a reflected from the measurement surface passes through the objective lens 45 again, passes through the mirror 42, the mirror 43, and the mirror 44, and forms an image on the optical position detection device 47. In this case, the test object is the aspherical lens 50, the mirror piece 15 or the mirror piece 16, and the measurement surface is the optical surface 51a, the optical surface 51b, the molding surface 15a or the molding surface 16a.

  When the focus of the objective lens 45 does not match the surface to be measured, the imaging position of the optical position detection device 47 changes from the reference position. Therefore, this position change is detected by the optical position detection device 47, and the moving mechanism 46 moves the focus of the objective lens 45 in the direction matching the surface to be measured. The height of the measurement target surface 1 in the Z-axis direction can be measured by the amount of movement of the objective lens 45 when the focus is achieved. Further, the position of the laser beam 41a in the XY plane of the surface to be measured can be determined by the amount of movement of the XY stage 48 on which the test object is placed. In this way, the three-dimensional shape of the measurement surface of the test object can be measured.

In the case of the present embodiment, the shapes of the molding surface 15a, the molding surface 16a, the optical surface 51a, and the optical surface 51b are measured based on the measurement result of the three-dimensional shape. And
Hereinafter, an example of the operation of the present embodiment will be described with reference to the flowchart of FIG. In the present embodiment, the temporary optical element is an aspheric lens. The aspheric surface has a rotationally symmetric shape with respect to the optical axis.

  First, the mirror piece 15 and the mirror piece 16 before correction processing are used as temporary mirror pieces. As described above, the temporary mirror surface piece has a molding surface 15a and a molding surface 16a having an aspheric shape, and the cavity 17 formed by the temporary mirror surface piece has a lens shape with two aspheric surfaces. is there. In this example, the shape of the cavity 17 is an example of a lens shape in which two optical surfaces are aspherical. However, one optical surface is spherical, two optical surfaces are spherical, and one optical surface is planar. Two optical surfaces may have a planar shape, one optical surface may have a free curved surface shape without a rotational symmetry axis, and two optical surfaces may have a free curved surface shape without a rotational symmetry axis.

  A molten resin injected from an injection molding unit (not shown) is filled into a cavity 17 formed by a temporary mirror surface piece through the sprue 19 and the runner 18 of FIG. Thereafter, the filled resin is cooled to form an aspheric lens 50 (temporary optical element) (step 101).

  In this case, as shown in FIG. 6, the aspherical lens 50 has a shape in which, for example, a lens portion 51, a surrounding lens frame 52, and a boss 53 protruding from the lens frame 52 are integrally formed of resin. Presents. In order to simplify the description, in FIG. 2, only the portion of the cavity 70 corresponding to the lens portion 51 is shown.

  Next, the amount of eccentricity of the temporary optical element taken out from the molding apparatus 10 is calculated. In the present embodiment, the surface shape of the provisional optical element is a rotationally symmetric shape. Therefore, the reference axis of the optical surface is the optical axis. The amount of eccentricity is the amount of deviation of the optical axis of the optical surface from the design value. In the present embodiment, as shown in FIG. 6, a boss 53 is provided outside the effective diameter of the optical surface 51a and the optical surface 51b. The position of the boss 53 becomes the reference position. Therefore, first, the position (reference position) of the central axis 53a of the boss 53 is calculated (step 102). Next, the positions of the optical axis A1 and the optical axis A2 are calculated (step 103). Then, the distance from the central axis 53a is calculated for each of the optical axis A1 of the optical surface 51a and the optical axis A2 of the optical surface 51b with reference to the central axis 53a. On the other hand, based on the design value, the distance from the central axis of the boss 53 to the optical axis of the optical surface 51a and the distance from the central axis of the boss 53 to the optical axis of the optical surface 51b are calculated. This calculation may be performed in advance. Subsequently, the amount of deviation (Δx, Δy) between the positions of the optical axis A1 and the optical axis A2 is obtained as an eccentric amount from the distance based on the measurement and the distance based on the design value (step 104).

  The boss 53 is used as a contact portion (abutting portion) with a frame component (not shown) such as a lens frame to which the aspheric lens 50 is attached. When contacting, the boss 53 becomes a reference. Therefore, in the present embodiment, the center axis 53a of the boss 53 (that is, the center of the hole of the frame part into which the boss 53 is fitted) can be used as a reference. When the contact portion between the aspherical lens 50 and the frame part is a flat surface, the flat surface is used as a reference.

 When calculating the central axis 53a of the boss 53, the optical axis A1, and the optical axis A2, the optical surface 51a, the optical surface 51b, and further, using the non-contact three-dimensional measuring device 40 illustrated in FIG. 4 as described above. The surface shape of the boss 53 is measured. Then, the optical axis A1, the optical axis A2, and further the central axis 53a are calculated from the three-dimensional shape of the optical surface 51a, the optical surface 51b, and further the boss 53.

  Subsequently, the position of the optical axis A0 on the molding surface (in this case, the molding surface 16a and the molding surface 15a) of the temporary mirror surface piece used for manufacturing the aspheric lens 50 (temporary optical element) is calculated (step 105). The optical axis A0 optical axis position in the molding surface 16a is derived on the basis of the movable mold plate 14 on the temporary mirror surface piece side and the mold contact portion (outer peripheral portion) with respect to the mirror surface piece 16. Here, the reference may be the outermost periphery instead of the die contact portion of the temporary mirror surface piece.

  In the case of the present embodiment, as illustrated in FIG. 5, the workpiece is held in the processing jig 31 via the outer peripheral portion of the mirror piece 15 (mirror piece 16). Here, the positional relationship between the mirror surface piece 15 and the mirror surface piece 16 and the processing jig 31 is known. Therefore, the mirror piece 15 (mirror piece 16) is placed on the XY stage 48 of the non-contact three-dimensional measuring device 40, and the shape of the molding surface 15a (molding surface 16a) is measured. Then, based on the measurement result, the optical axis A0 is calculated. In this way, the position of the optical axis A0 is set to the outer periphery of the specular piece 15 and the specular piece 16 (the contact portion for the movable mold 14 and the specular piece 16). ) As a standard.

  Subsequently, the position of the optical axis A0 within the surface of the temporary mirror surface piece is corrected. For this correction, the shift amount between the positions of the optical axis A1 and the optical axis A2 calculated in step 104 is used. That is, the position of the new optical axis A0 'is calculated based on the amount of deviation between the positions of the optical axis A1 and the optical axis A2. Specifically, the position of the optical axis A0 is shifted to the position of the new optical axis A0 'so that the amount of deviation between the positions of the optical axis A1 and the optical axis A2 becomes zero. The shift amount at this time becomes a correction value (step 106). Then, correction processing of the temporary mirror surface pieces (mirror surface piece 16, mirror surface piece 15), that is, correction processing of the molding surface 15a and the molding surface 16a, so that the position (shifted position) of the new optical axis A0 ′ becomes the optical axis. (Step 107). Then, the mirror piece 16 and the mirror piece 15 for molding the product are produced (step 108).

  Specifically, as illustrated in FIG. 3, the correction value described above is input to the three-dimensional processing controller 25 as the optical axis correction data 27. Then, the temporary mirror surface piece is corrected so that the optical axis A0 moves by this correction value. In this way, the mirror piece 15 and the mirror piece 16 used for forming the product are manufactured.

Thereafter, molding is performed using the mirror piece 16 and the mirror piece 15 in which the position of the optical axis A0 is corrected, thereby producing an aspherical lens 50 as a product (step 108).
Thus, in the present embodiment, the amount of deviation of the optical axis A1 of the temporary aspheric lens 50 formed by the temporary mirror surface piece is calculated, and the amount of deviation of the optical axis A0 of the temporary mirror surface piece itself is also calculated. Then, the temporary mirror surface piece (molded surface 16a, mirror surface piece 15) is corrected so as to cancel the deviation between the optical axis A1 and the optical axis A2 of the temporarily formed aspheric lens 50, and the optical axis A0 is corrected. Since the mirror piece 16 and the mirror piece 15 are manufactured and the aspherical lens 50 of the product is formed using the mirror piece 16 and the mirror piece 15, the optical axis A1 and the optical axis A2 are not highly eccentric and have high accuracy. An optical element such as the spherical lens 50 can be obtained.

  Further, the positions of the optical axis A1 and the optical axis A2 are calculated using the boss 53 of the aspheric lens 50 as a reference. Accordingly, the optical axis A1 and the optical axis A2 of the corrected optical surface 51a and optical surface 51b are accurately positioned with respect to the boss 53. Therefore, if a frame part such as a lens frame (not shown) is manufactured based on the boss 53, the mounting accuracy of the aspherical lens 50 to the frame part such as a lens frame is improved.

Further, it is not necessary to perform complicated operations such as correcting the mounting positions of the mirror piece 15 and the mirror piece 16 with respect to the fixed mold plate 12 and the movable mold plate 14 each time.
That is, the position of the optical axis A0 calculated from the temporary mirror surface piece reflects the positional deviation of the optical axis A0 when the mirror surface piece 15 and the mirror surface piece 16 are attached to the fixed mold plate 12 and the movable mold plate 14. Accordingly, with the calculated optical axis A0 as a reference, the mirror piece 15 and the mirror piece 16 are corrected so as to cancel the deviation between the optical axis A1 and the optical axis A2 of the temporary aspheric lens 50. By doing in this way, in the correction process of the specular piece 15 and the specular piece 16, the mounting error of the specular piece 15 and the specular piece 16 with respect to the fixed mold 12 and the movable mold 14 can be included in the correction process.

Thereby, for example, for each of the optical surface 51a and the optical surface 51b, an optical element having an optical axis position eccentricity of ± 10 μm or less can be obtained.
Further, by producing an optical element such as the aspherical lens 50 by injection molding using the molding apparatus 10, a low-cost optical element can be obtained. Further, at the same time as the correction processing of the reference axis, for example, correction processing for canceling the shape error of the optical surface may be performed. By performing such surface shape correction processing, the lead time can be further shortened.

(Embodiment 2)
FIG. 7 is a conceptual diagram showing an example of the operation of the optical element manufacturing method according to the second embodiment of the present invention.

In the description of the above-described first embodiment, as illustrated in FIG. 6, the case where the eccentric amounts of the optical axis A1 and the optical axis A2 of the aspherical lens 50 are calculated based on the central axis 53a of the boss 53 is illustrated. .
On the other hand, in the present embodiment, as illustrated in FIG. 7, the deviation (Δx, Δy) of the optical axis A2 on the optical surface 51b side with reference to the optical axis A1 of the one optical surface 51a. Is calculated. And based on this calculation result, the optical axis A0 of the specular piece 15 and the specular piece 16 is corrected.

This improves the accuracy of the relative concentricity with respect to the optical axis A1 of the optical surface 51a and the optical axis A2 of the optical surface 51b.
(Embodiment 3)
In the third embodiment, a case will be described in which the present invention is applied to an optical element having a lens shape that is not rotationally symmetric about the optical axis. Examples of such an optical element include a prism and the like (a prism having a non-rotationally symmetric surface, a free-form surface prism).

That is, FIG. 8 is a cross-sectional view of the optical element of the third embodiment, and FIG. 9 is a perspective view thereof.
The prism 80 according to the third embodiment includes an optical surface 81, an optical surface 82, an optical surface 83, and a side surface 85. The side surface portion 85 is two planes formed so as to face each other, and is disposed so as to be parallel to each other. An optical surface 81, an optical surface 82, and an optical surface 83 are formed on the side surface portion 85 in the orthogonal direction. Here, the free-form surface is a non-rotationally symmetric shape. Therefore, there is no concept of an optical axis. However, there is a reference axis that defines the surface shape. Therefore, in this embodiment, the reference axis is referred to as an optical axis for convenience.

  The optical surface 81 is an outwardly convex free-form surface and has an optical axis 81a. The optical surface 82 is a free-form surface slightly recessed inward and has an optical axis 82a. The optical surface 83 is composed of a flat portion 84 and a concave free-form surface formed at the center of the flat portion 84, and has an optical axis 83a.

  In such a configuration, the light incident from the optical surface 81 is converged on the light face 81. This light is reflected by the optical surface 82 in the direction of the optical surface 83. Further, the reflected light is converged by the optical surface 83 and emitted to the outside. The optical surface 81 and the optical surface 82 are set to have a free-form surface so as to remove the aberration of light that has passed through the prism 80, for example.

FIG. 10 is a cross-sectional view showing an example of a molding apparatus 60 used for molding the prism 80 having the above-described shape.
In addition, the same code | symbol is attached | subjected to the component which is common in the shaping | molding apparatus 10 of FIG. 2, the overlapping description is omitted, and only a different point is demonstrated.

  That is, in the forming device 60, the free-form surface specular piece 71, the free-form surface specular piece 73, and the free-form surface specular piece 73 are used to form the three optical surfaces 81, 82, and 83 of the prism 80.

  The free curved surface specular piece 71 and the free curved surface specular piece 72 are embedded in the fixed mold plate 12 and the movable mold plate 14, respectively. The free-form specular piece 71 and the free-form specular piece 72 are arranged so that the forming surface 71a and the forming surface 72a face each other in the direction in which the fixed mold plate 12 and the movable mold plate 14 move relatively.

  A free-form mirror surface piece 73 corresponding to the optical surface 83 has a convex molding surface 73a. And it arrange | positions at the type | mold matching surface of the fixed mold plate 12 and the movable mold plate 14 so that the convex shaping | molding surface 73a may face in a type | mold. This free-form surface mirror piece 73 is held by a slide member 74. The slide member 74 is displaced in a direction orthogonal to the facing direction of the fixed mold plate 12 and the movable mold plate 14. Therefore, the convex molding surface 73a is also directed in a direction orthogonal to the opposing direction of the fixed mold plate 12 and the movable mold plate 14.

  Then, the fixed mold plate 12 and the movable mold plate 14 are brought into close contact with each other so that a mold clamping state is obtained. In this clamping state (the state shown in FIG. 10), the molding surface at the tip of the free-form mirror surface piece 73 is between the molding surface 71a of the free-form surface mirror piece 71 and the molding surface 72a of the free-form surface mirror piece 72. 73a enters. By doing so, the cavity 70 forming the contour shape of the prism 80 is formed.

  Although not particularly shown, when the mold clamping state is released (release), first, the slide member 74 moves in a direction away from the cavity 70. Along with this, the free-form mirror piece 73 is displaced in the direction of retreating from the inside of the cavity 70 to the outside. Thereafter, the fixed mold plate 12 and the movable mold plate 14 are displaced so as to be separated from each other.

  In forming the prism 80, in the case of the present embodiment, first, the free-form surface specular piece 71, the free-form surface specular piece 72, and the free-form surface specular piece 73 are mounted on the forming apparatus 60 as temporary specular pieces, The prism 80 is formed.

  Then, the outer shape of the temporary prism 80 obtained is measured by the non-contact three-dimensional measuring device 40 illustrated in FIG. Subsequently, using the optical axis 83a of the optical surface 83 as a reference (step 102), the positions of the other optical axis 81a and the optical axis 82a are calculated (step 103). Thereafter, the amount of deviation is calculated (step 104).

  Further, the optical surface A10, the optical axis A11, and the optical axis A10 of each of the temporary mirror surface pieces, that is, the free-form mirror surface piece 71, the free-form surface mirror piece 72, and the free-form mirror surface piece 73, the forming surface 71a, the forming surface 72a, and the forming surface 73a, respectively. The position of the optical axis A12 is measured by the non-contact three-dimensional measuring device 40 (step 105). At that time, the state held by the processing jig 32, the processing jig 33, and the processing jig 34 is used as a reference.

  Then, optical axis correction data 27 is generated. The correction data is calculated using the deviation amounts of the individual optical axes 81a and 82a calculated in step 104 and the positions of the optical axes A10 to A12 calculated in step 105. In this case, the correction is a correction in which the positions of the optical axis A10 to the optical axis A12 calculated in step 105 are displaced in a direction that cancels out the deviation amounts of the individual optical axes 81a and 82a calculated in step 104. Become. Then, as illustrated in FIGS. 11, 12, and 13, the mirror surface piece processing apparatus 20 performs correction processing of the free curved surface mirror piece 71, the free curved surface mirror piece 72, and the free curved surface mirror piece 73 (step 107). ).

  In this correction processing, as illustrated in FIG. 11, the free-form mirror surface piece 71 is positioned on the dedicated processing jig 32 by the fixing screw 32a and the fixing screw 32b. Then, the molding surface 71a is corrected so that the position of the optical axis A11 of the molding surface 71a becomes the position of a new optical axis A11 '. The new optical axis A11 'is a position where the optical axis A11 is moved in a direction that cancels out the deviation amount of the optical axis 81a.

  Similarly, as illustrated in FIG. 12, the free-form surface mirror piece 72 is positioned on a dedicated processing jig 33 by a fixing screw 33a and a fixing screw 33b. Then, correction processing is performed so that the position of the optical axis A12 becomes the position of the new optical axis A12 '. The new optical axis A12 'is a position where the optical axis A21 is moved in a direction that cancels out the deviation amount of the optical axis 82a.

  Further, as illustrated in FIG. 13, the free-form mirror surface piece 73 is positioned on the dedicated processing jig 34 by the fixing screw 34a and the fixing screw 34b. Then, correction processing is performed so that the position of the optical axis A10 becomes the position of the new optical axis A10 '. The new optical axis A10 'is a position where the optical axis A10 is moved in a direction that cancels out the deviation amount of the optical axis 83a.

  Then, the free-form mirror piece 71, free-form mirror piece 72, and free-form mirror piece 73 subjected to this correction processing are mounted on the forming device 60, and the product prism 80 is formed (step 108).

  As described above, even in the non-rotationally symmetric prism 80 having a complicated shape, it is possible to reduce the amount of deviation among the individual optical axes 81a, 82a, and 83a. That is, in the optical element, the relative positional accuracy among the optical axis 81a, the optical axis 82a, and the optical axis 83a can be improved.

  Moreover, by using the optical axis of at least one optical surface among the plurality of optical surfaces 81, 82, and 83 as a reference, the optical axis between the optical surface used as a reference and another optical axis are used. A highly accurate optical element with a small amount of eccentricity can be realized.

  For example, even in an optical element having a plurality of optical surfaces such as the prism 80, it is possible to obtain a highly accurate prism 80 in which the decentering amounts of the optical axis 81a, the optical axis 82a, and the optical axis 83a are ± 10 μm or less.

Needless to say, the present invention is not limited to the configuration exemplified in the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the optical element is not limited to the free-form surface lens and the prism exemplified in the above-described embodiment, and can be widely applied to general optical elements manufactured by resin molding.

  Further, the processing method and the measuring method of the optical element are not limited to the methods exemplified in the above embodiment.

It is a flowchart which shows an example of the manufacturing method of the specular piece and the manufacturing method of an optical element which are one embodiment of this invention. It is sectional drawing which shows an example of a structure of the shaping | molding apparatus used for the manufacturing method of the optical element which is one embodiment of this invention. It is a perspective view which shows an example of a structure of the mirror surface piece processing apparatus 20 used for the manufacturing method of the mirror surface piece which is one embodiment of this invention. It is a conceptual diagram which shows an example of a structure of the non-contact three-dimensional measuring machine used for the manufacturing method of the specular piece which is one embodiment of this invention, and the manufacturing method of an optical element. It is a conceptual diagram which shows an example of the measuring method of the temporary specular piece in the manufacturing method of the specular piece which is one embodiment of this invention, and the manufacturing method of an optical element. It is a conceptual diagram which shows an example of the measuring method of the optical element obtained with the manufacturing method of the optical element which is one embodiment of this invention. It is a conceptual diagram which shows an example of an effect | action of the manufacturing method of the optical element which is other embodiment of this invention. It is sectional drawing of the optical element manufactured with the manufacturing method of the optical element which is further another embodiment of this invention. It is a perspective view of the optical element manufactured with the manufacturing method of the optical element which is further another embodiment of this invention. It is sectional drawing which shows an example of the shaping | molding apparatus used with the manufacturing method of the optical element which is further another embodiment of this invention. It is a perspective view which shows an example of the processing method of the mirror piece used in the manufacturing method of the optical element which is further another embodiment of this invention. It is a perspective view which shows an example of the processing method of the mirror piece used in the manufacturing method of the optical element which is further another embodiment of this invention. It is a perspective view which shows an example of the processing method of the mirror piece used in the manufacturing method of the optical element which is further another embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Molding device 11 Fixed plate 12 Fixed mold plate 13 Movable plate 13a Ejection pin 13b Ejection plate 13c Spacer block 14 Movable mold plate 15 Mirror surface piece 15a Molding surface 16 Mirror surface piece 16a Molding surface 17 Cavity 18 Runner 19 Spru 20 Mirror surface piece processing device 21 XY stage 22 Z-axis column 23 Tool arm 24 Cutting tool 24a Processing locus 25 Three-dimensional processing controller 26 Design data 27 Optical axis correction data 31 Processing jig 31a Fixing screw 32 Processing jig 32a Fixing screw 32b Fixing screw 33 Processing jig 33a Fixing screw 33b Fixing screw 34 Processing jig 34a Fixing screw 34b Fixing screw 40 Non-contact three-dimensional measuring machine 41 Laser 41a Laser light 42 Mirror 43 Mirror 44 Mirror 45 Objective lens 46 Moving mechanism 47 Optical position detection device 48 XY stage 4 Measuring jig 50 Aspherical lens 51 Lens part 51a Optical surface 51b Optical surface 52 Lens frame 53 Boss 53a Central axis 60 Molding device 70 Cavity 71 Free-form mirror surface piece 71a Molding surface 72 Free-form surface mirror piece 72a Molding surface 73 Free-form surface mirror piece 73a Molding surface 74 Slide member 80 Prism 81 Optical surface 81a Optical axis 82 Optical surface 82a Optical axis 83 Optical surface 83a Optical axis 84 Flat surface 85 Side surface A0 Optical axis A1 Optical axis A2 Optical axis A10 Optical axis A11 Optical axis A12 Optical axis

Claims (10)

Forming a temporary optical element using the temporary mirror surface piece;
Measuring the shape of the optical surface of the temporary optical element to obtain a reference axis position in the measured shape;
Obtaining a position of a reference axis position in the design shape of the temporary optical element;
Calculating a relative deviation amount between a reference axis position in the measurement shape and a reference axis position in the design shape;
Measuring the shape of the mirror surface of the temporary mirror surface piece, and calculating a reference axis position in the measurement shape of the mirror surface;
Processing the mirror surface of the temporary mirror surface piece so as to correct the reference axis position of the temporary mirror surface piece based on the amount of deviation, and producing a mirror surface piece;
A method for producing a mirror-finished piece. In the manufacturing method of the specular piece of Claim 1,
In producing the temporary mirror surface piece, a method for producing the mirror surface piece, comprising a step of relatively moving the mirror surface of the temporary mirror surface piece and a processing tool in two directions orthogonal to each other. In the manufacturing method of the specular piece of Claim 1 or Claim 2,
In the step of producing the specular piece, a method of producing the specular piece, wherein the mirror surface of the temporary specular piece and the processing tool are relatively moved in two orthogonal directions. In the manufacturing method of the specular piece of any one of Claims 1 thru | or 3,
The step of obtaining the reference axis position in the measurement shape and the step of obtaining the position of the reference axis position in the design shape are performed based on the position of the reference object provided in the temporary optical element. Manufacturing method. In the manufacturing method of the specular piece of Claim 4,
The reference is one,
A method of manufacturing a specular piece, wherein the position of the reference axis is calculated based on the one reference object for each of the plurality of optical surfaces. In the manufacturing method of the specular piece of Claim 4,
The reference object is the same as the number of the optical surfaces,
A method of manufacturing a specular piece, wherein the position of the reference axis is calculated based on each reference object for each of the plurality of optical surfaces. In the manufacturing method of the specular piece of Claim 4,
The reference object is less than the number of the optical surfaces,
A method for producing a specular piece, comprising: calculating a position of the reference axis based on a common reference object for at least two of the plurality of optical surfaces. A method of manufacturing an optical element that molds an optical element using a mirror piece,
A method for manufacturing an optical element, comprising using the mirror piece produced by the method for producing a mirror piece according to any one of claims 1 to 7.   An optical element manufactured using the method for manufacturing an optical element according to claim 8. The optical element according to claim 9, wherein
The optical element is a prism having a curved surface shape having no rotational symmetry axis on at least one optical surface.

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