JP2008216419A - Manufacturing method for optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for highly precisely manufacturing an optical element such as a beam forming element at high productivity while shortening a period of time required for an alignment operation in a cutting process. <P>SOLUTION: Glass molded bodies, each having at least one optical face and sides, are cut while kept fixed to a fixing tool, and thus the optical elements are obtained. At least one of the sides has a molded transfer face. The fixing tool has arrangement reference faces for bringing the molded transfer faces of the plurality of glass molded body into contact with them. While the molded transfer faces of the glass molded bodies are kept in contact with the arrangement reference faces of the fixing tool and the plurality of glass molded bodies are arranged and fixed on straight lines, the glass molded bodies are cut. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing an optical element such as a beam shaping element for shaping an elliptical output beam output from a semiconductor laser into a circle.

  Generally, a semiconductor laser is used as a light source in a pickup device for recording / reproducing information on / from an optical information recording medium such as a DVD. Since the output beam from the semiconductor laser is emitted from the end face of the thin active layer, the beam has an elliptical cross section. By using such an elliptical beam after shaping it into a circular beam by using a beam shaping element, it becomes possible to increase the efficiency of use of the beam and improve the accuracy of recording and reproduction. In particular, since the intensity of an output beam tends to be insufficient for a blue semiconductor laser, such a beam shaping element is particularly important in a pickup device using a blue semiconductor laser as a light source, and has attracted attention.

  As a beam shaping element that is an optical element for shaping an elliptical beam into a circular beam, for example, a beam shaping element (lens) having a cylindrical surface having a curvature only in a direction corresponding to the minor axis direction of the beam cross section. Is known (see, for example, Patent Document 1). In addition, as a method for manufacturing such a beam shaping element, a manufacturing method using a press molding method in which a glass material is pressure-molded with a molding die has been proposed (see, for example, Patent Documents 2 and 3).

In general, such a beam shaping element is required to have high positioning accuracy with respect to a light source or the like when incorporated. For this reason, Patent Document 2 proposes a method in which a side surface of a glass molded body is formed by transfer by molding, and the molded transfer surface is used as a positioning reference surface for incorporation. Patent Document 3 proposes a method of producing a molded product in which a plurality of beam shaping elements are arranged and cutting the molded product into individual beam shaping elements from the viewpoint of improving productivity.
JP 2002-208159 A JP 2006-301249 A JP 2006-298692 A

  However, there is an increasing demand for downsizing and weight reduction of the beam shaping element, and due to manufacturing restrictions, a method of using the molding transfer surface of the glass molded body proposed in Patent Document 2 as a positioning reference surface for incorporation is used. It can be difficult. In such a case, the glass molded body is cut to a predetermined size to be miniaturized, and the obtained cut surface is used as a positioning reference surface for incorporation.

  In general, the glass molded body is cut by using a cutting device (dicer) of a type in which a dicing blade is rotated for cutting. The dicer is suitable for performing a linear cutting process with high accuracy, but requires an alignment operation for adjusting the cutting position and angle. The alignment work may be performed directly by an operator while observing an enlarged image of the glass molded body, or may be automated using an image processing apparatus or the like. However, since the beam shaping element is required to have very high positioning accuracy, it takes a lot of time for this alignment work in any case, and productivity when manufacturing a large number of beam shaping elements. It was a major factor that hindered

  This also applies to the case where a molded product in which a plurality of beam shaping elements proposed in Patent Document 3 are arranged into individual beam shaping elements, and the time required for alignment work for cutting is reduced. How to shorten it was a big issue.

  The present invention has been made in view of the technical problems as described above, and an object of the present invention is to shorten the time required for the alignment work in the cutting process, and to make an optical element such as a beam shaping element highly accurate. And it is providing the manufacturing method for manufacturing with high productivity.

  In order to solve the above problems, the present invention has the following features.

  1. In a method of manufacturing an optical element for obtaining an optical element by cutting a glass molded body having at least one optical surface and a side face while being fixed to a fixing jig, at least one of the side faces has a molding transfer surface. The fixing jig has an array reference surface for contacting the molding transfer surfaces of the plurality of glass molded bodies, the molding transfer surface is in contact with the array reference surfaces, and the plurality of glass molded bodies are A method of manufacturing an optical element, comprising a cutting step of cutting in a state of being arranged and fixed on a straight line.

  2. The fixing jig has a plurality of the alignment reference surfaces, and the cutting step includes a plurality of cuttings parallel to each other in a state where the plurality of glass molded bodies are arranged and fixed on a plurality of parallel lines. 2. The method of manufacturing an optical element according to 1 above, wherein the method is a step of cutting a line.

  3. 3. The method of manufacturing an optical element according to 2, wherein the fixing jig includes an array member having two array reference surfaces facing each other.

  4). Using a plurality of the fixing jigs that have substantially the same interval between the corresponding array reference planes, the cutting line intervals in the cutting step are the same regardless of which of the plurality of fixing jigs is used. The method of manufacturing an optical element according to 2 or 3, characterized in that the optical element is cut as the above-mentioned setting.

  5. 5. The method of manufacturing an optical element according to any one of 1 to 4, wherein at least one of the optical surfaces is a cylindrical surface.

  6). 6. The method of manufacturing an optical element according to any one of 1 to 5, wherein the optical element is a beam shaping element for shaping an elliptical output beam output from a semiconductor laser into a circular shape. .

  According to the present invention, a large number of glass molded bodies can be cut by a single alignment operation. As a result, the alignment work time required for each optical element is shortened, and an optical element such as a beam shaping element can be manufactured with high accuracy and high productivity.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Glass compacts and optical elements)
The present invention is particularly preferably used for manufacturing a beam shaping element for shaping an elliptical output beam output from a semiconductor laser into a circle. However, the optical element targeted by the present invention is not limited to this, and can be applied to the production of an optical element having at least one optical surface such as various lenses and mirrors.

  FIG. 5 shows a glass molded body 10 used in the present invention, and FIG. 6 shows a beam shaping element 20 manufactured by cutting the glass molded body 10.

  The glass molded body 10 includes a molding surface 11 including an optical surface 11c (surface CDEedc), a molding surface 12 including an optical surface 12c (surface JKLlkj), and side surfaces 13, 14, 15, and 16. The optical surface 11c is a cylindrical surface, and has no curvature in a predetermined direction (y direction in FIG. 5; hereinafter also referred to as generatrix direction) in a plane perpendicular to the optical axis (z direction in FIG. 5). It has a curvature only in the direction perpendicular to it (the x direction in FIG. 5; hereinafter also referred to as the sub-wire direction). The optical surface 12c is a similar cylindrical surface. The generatrix directions of the optical surface 11c and the optical surface 12c are parallel to each other.

  Here, a case where both of the two optical surfaces 11c and 12c facing each other are cylindrical surfaces will be described as an example, but the glass molded body (beam shaping element) targeted by the present invention is not limited to this. For example, a glass molded body in which one optical surface is a cylindrical surface and the other surface is flat or spherical, or one optical surface is a cylindrical surface and the other surface has a curvature in the generatrix direction. The present invention can also be applied to glass molded bodies having toroidal surfaces with different curvatures. In the cylindrical surface, a line (CDE, JKL, etc.) intersecting with a surface perpendicular to the generatrix direction may have an arc shape or an aspherical component.

  There is no restriction | limiting in particular in the magnitude | size of the glass molded object 10, The thing of various magnitude | sizes can be used according to a use. In general, when the cylindrical surface has a length in the generatrix direction of 1 mm to 20 mm, a length in the subwire direction of 1 mm to 20 mm, and a thickness in the optical axis direction of about 0.5 mm to 10 mm. There are many.

  The beam shaping element 20 is manufactured by cutting the glass molded body 10 with a surface BbmM and a surface FfiI and removing both ends. At this time, at least one of the cut surfaces 17 (surface BbmM) and 18 (surface FfiI) is formed at a predetermined distance from the optical surfaces 11c and 12c perpendicular to the direction of the sub-line of the optical surfaces 11c and 12c. Therefore, at least one of the cut surfaces 17 and 18 can be used as a positioning reference surface for incorporation. The cut surface used as the positioning reference surface preferably has a smaller variation in the distance from the optical surface, and is usually preferably 50 μm or less.

  Two side surfaces 15 and 16 parallel to the cut surfaces 17 and 18 of the glass molded body 10 are molding transfer surfaces. Since the molding transfer surface is formed by transferring the molding die surface, there is very little variation in the distance from the optical surface. In the present invention, since this molding transfer surface is brought into contact with an array reference surface of a fixing jig, which will be described later, and a plurality of glass molded bodies are arranged in a straight line for cutting, a large number of glass molded bodies can be obtained by a single cutting operation. Can be cut with high accuracy.

  FIG. 7 is a view showing another example of the glass molded body used in the present invention, and shows a cross section perpendicular to the generatrix direction of the cylindrical surface. Both the glass molded body 10a shown in FIG. 7 (a) and the glass molded body 10b shown in FIG. 7 (b) have two cylindrical surfaces facing each other in the same manner as the glass molded body 10 shown in FIG. However, the range of the molding transfer surface is different. The side surface 16a of the glass molded body 10a has a molding transfer surface 17a only at the central portion in the thickness direction, and has portions 18a formed at both ends without being in contact with the molding die. In addition to the molding transfer surface 17b, the side surface 16b of the glass molded body 10b has a portion 18b protruding outside without contacting the molding die. As described above, the glass molded body used in the present invention only needs to have a molding transfer surface on at least a part of the side surface, and even if the side surface includes a portion formed without contacting the molding die. good. Further, it is not necessary that all side surfaces of the glass molded body have a molding transfer surface, and it is sufficient that at least one side surface has a molding transfer surface.

  The glass molded body is produced by a press molding method in which a glass material is pressure-molded with a molding die. There is no restriction | limiting in particular in the method and molding conditions of a press molding, A well-known method can be used as a press molding method of a glass-made optical element. For example, (1) A glass material for molding having a predetermined mass and shape is prepared in advance, the glass material for molding is heated to a temperature at which the glass can be deformed together with upper and lower molds, and then the glass material for molding is formed into upper and lower parts. A method of obtaining a glass molded body having an optical surface transferred by pressure molding with a mold, or (2) heating the upper and lower molding molds to a predetermined temperature in advance and supplying molten glass to the surface of the lower mold For example, a method of obtaining a glass molded body having an optical surface transferred by pressure molding with upper and lower molds while the supplied glass material is still at a deformable temperature can be used.

  FIG. 8 is a sectional view showing an example of a molding die for molding the glass molded body 10. The molding die 30 shown in FIG. 8 includes an upper mold 31 having a molding surface 34 for forming the molding surface 12 of the glass molded body 10 and a molding surface 35 for forming the molding surface 11 of the glass molded body 10. And a side member 33 having a molding surface 36 for forming the side surfaces 15 and 16 of the glass molded body.

  By pressing the supplied glass material with the molding die 30, the molded surface 11 including the optical surface 11c, the molded surface 12 including the optical surface 12c, and the side surfaces 15 and 16 are formed by transfer. Can be obtained. At this time, by appropriately setting the size of the fitting portion between the upper mold 31 and the lower mold 32 and the side member 33, the molding transfer surfaces formed on the side surfaces 15 and 16 of the glass molded body 10 are predetermined from the optical surface. Distance. Since this distance can also minimize variations in the production of a large number of glass molded bodies, the molding transfer surface is fixed in a state of being arranged in a straight line, and a plurality of glass molded bodies are cut together. Thereby, many glass molded objects can be cut | disconnected with high precision by one cutting operation.

  There is no restriction | limiting in particular in the kind of glass which can be used, The well-known glass used for a glass-made optical element can be selected suitably, and can be used. Examples thereof include phosphate glass and lanthanum glass.

(Cutting process)
Next, the cutting process in the present invention will be described. The cutting step in the present invention is a step in which the molding transfer surface of the glass molded body is brought into contact with the arrangement reference surface of the fixing jig, and a plurality of glass molded bodies are arranged in a straight line and fixed and cut. Ingredients)
1 and 2 are views showing an example of a fixing jig used in the present invention. FIG. 1 is a view of a fixing jig 40 to which a plurality of glass molded bodies 10 are fixed as viewed from the molding surface 11 side of the glass molded body 10, and FIG. 2 is a cross-sectional view taken along line AA ′. The fixing jig 40 has an array reference surface 41 formed on the main body 44. The glass molded body 10 is pressed against the arrangement reference surface 41 by the pressing plate 42 urged by the spring 43, and the glass molding 10 is arranged in a straight line by contacting the side surface 16 which is a molding transfer surface with the arrangement reference surface 41. In this state, the molding surface 12 of the glass molded body 10 is fixed to the main body 41 of the fixing jig 40.

  There is no restriction | limiting in particular in the method for fixing the glass forming body 10 to the fixing jig 40, A well-known method can be used suitably. For example, the method of fixing using various adhesives and adhesives, such as a hot-melt-type adhesive agent, and the method of fixing using adhesive tapes, such as a dicing tape, are mentioned.

  Although the arrangement reference surface 41 of the fixing jig 40 shown in FIG. 2 is a flat surface, the shape of the arrangement reference surface 41 is not limited to this in the present invention, and the glass molded body 10 is brought into contact with the molding transfer surface. Any shape that can be arranged on a straight line is acceptable. For example, a shape having a taper or a curved surface may be used. Moreover, there is no restriction | limiting in particular in the material and magnitude | size of a fixing jig.

  The fixed glass molded body 10 is linearly cut along the cutting line 46 after the alignment operation. The main body 44 of the fixing jig 40 is provided with a relief groove 45 along the cutting line 46. The escape groove 45 is formed with a depth and a width so that the dicing blade does not contact the main body 44 during cutting. By providing such a relief groove 45, it is possible to prevent an excessive load from being applied to the dicing blade during cutting, and it is possible to cut the glass molded body 10 with higher accuracy.

(alignment)
After fixing the glass molded body 10 to the fixing jig 40, an alignment operation for adjusting the position and angle of the cutting line is performed.

  First, the fixing jig 40 to which the glass molded body 10 is fixed is fixed to a cutting stage that can move and rotate. The fixing method may be appropriately selected from known methods such as a method using vacuum adsorption, a method using an adhesive tape or an adhesive, and a method using freezing and fixing using a piezoelectric element. Thereafter, the position and angle of the fixing jig 40 are adjusted by moving and rotating the cutting stage so that the cutting line of the cutting device substantially coincides with the cutting line 46 of the glass molded body. In the present invention, since a plurality of glass molded bodies are arranged on a straight line, it is not necessary to perform alignment for each glass molded body, and cutting can be performed collectively by one alignment.

  Adjustment of the position and angle of the fixing jig 40 is performed based on an enlarged image. Manual adjustment in which the operator operates the cutting stage while viewing the image may be used, or an automatic adjustment method in which processing of the captured image and cutting stage control are performed by a computer may be used.

(Cut)
Although there is no restriction | limiting in the kind of cutting device, It is preferable to use the cutting device (dicer) using the dicing blade which can perform a linear cutting process with high precision easily. The type of the dicing blade is not particularly limited, and a known dicing blade such as a GC grindstone, a diamond blade, or a metal saw may be appropriately selected and used.

  3 and 4 are diagrams showing another example of the fixing jig used in the present invention. FIG. 3 is a view of the fixing jig 50 to which a plurality of glass molded bodies 10b are fixed as viewed from the molding surface 11 side of the glass molded body 10b, and FIG. 4 is a B-B ′ sectional view thereof. The fixing jig 50 includes a main body 54, a pressing plate 52, and a spring 53, and the main body 54 is provided with a relief groove 55. Further, the fixing jig 50 has an array member 58 having two array reference surfaces 51 facing each other.

  The molding transfer surface 17b of the glass molded body 10b is brought into contact with the two arrangement reference surfaces 51 of the fixing jig 50, and the glass molded body is fixed in a state of being arranged on two parallel straight lines. There are two cutting lines 56 per row of the glass molded body 10b, and there are a total of four cutting lines 56 in the two rows of glass molded body 10b. Among these, the distance L1 between the two cutting lines of the glass moldings 10b in the same row is known because it is the dimension of the beam shaping element to be produced. Moreover, if the distance L3 between the two arrangement reference planes 51 is measured in advance, the distance L2 between the cutting lines of the glass molded bodies in different rows can be obtained. Accordingly, in the alignment process, the position and angle of the fixing jig are adjusted with reference to any one cutting line, and the alignment is performed for each column by cutting in parallel at predetermined intervals (L1, L2). Without performing, it is possible to cut a large number of glass molded bodies 10b arranged in a plurality of rows with high accuracy.

  Here, the two arrangement reference surfaces 51 of the fixing jig 50 are two opposite faces of the arrangement member 58. In this way, by using the array member 58 having the two array reference surfaces 51 facing each other, the fixing having the plurality of array reference surfaces 51 so that the molding transfer surfaces 17b of the arrayed glass molded bodies 10b are parallel to each other. The jig 50 can be easily manufactured.

  Moreover, when cutting many glass molded objects 10b, in order to process more efficiently, several such fixing jigs 50 can be prepared and used in order. In this case, it is preferable that the fixing jig 50 is formed so that the interval L3 between the arrangement reference surfaces 51 is substantially the same. By making the interval L3 of the array reference plane 51 substantially the same, it is possible to cut any of a plurality of fixing jigs prepared without changing the setting of the cutting line interval every time the fixing jig is replaced. Cutting can be performed with the same interval between lines. Accordingly, the time required for replacing the fixing jig can be shortened, the generation of defective products due to a setting change error can be prevented, and an optical element such as a beam shaping element can be manufactured with higher productivity. . In this case, “substantially the same” is acceptable as long as the distance between the cut surface used as the positioning reference surface and the optical surface is acceptable in the specification of the optical element to be manufactured, and is usually about 50 μm or less. Is preferred.

  Furthermore, it is also preferable to use a fixing jig having three or more array reference surfaces. In this case, the intervals of the array reference planes of one fixing jig do not have to be all equal, and may be different. When a plurality of fixing jigs are prepared as described above, it is preferable that the intervals between the arrangement reference planes at corresponding positions are the same for all the fixing jigs. For example, if the interval between the y-th and z-th arrangement reference planes of the x-th fixing jig is written as Lxyz, L112 (the interval between the first and second arrangement reference planes of the first fixing jig) and L212 And L312, L123, L223, and L323 are preferably equal to each other. However, even if L112 and L123 are different, it is not necessary to change the setting of the interval between the cutting lines when the fixing jig is replaced.

It is the figure which looked at the fixing jig 40 with which the some glass molded object 10 was fixed from the molding surface 11 side of the glass molded object 10. FIG. It is A-A 'sectional drawing of the fixing jig 40 to which the some glass molded object 10 was fixed. It is the figure which looked at the fixing jig 50 with which the some glass molded object 10b was fixed from the molding surface 11 side of the glass molded object 10b. It is a B-B 'sectional view of fixing jig 50 to which a plurality of glass fabrication objects 10b were fixed. It is a figure which shows the glass molded object 10 used by this invention. It is a figure which shows the beam shaping element 20 manufactured by cut | disconnecting the glass molded object 10. FIG. It is a figure which shows another example of the glass forming body used by this invention. 1 is a cross-sectional view showing an example of a molding die for molding a glass molded body 10.

Explanation of symbols

10, 10a, 10b Glass molded body 11c, 12c Optical surface (cylindrical surface)
13, 14, 15, 16, 16a, 16b Side surface 17a, 17b Mold transfer surface 30 Mold 40, 50 Fixing jig 41, 51 Arrangement reference surface 45, 55 Escape groove 46, 56 Cutting line 58 Arrangement member L3 Arrangement reference Face spacing

Claims (6)

In a method of manufacturing an optical element for obtaining an optical element by cutting a glass molded body having at least one optical surface and a side surface while being fixed to a fixing jig,
At least one of the side surfaces has a molded transfer surface;
The fixing jig has an array reference surface for contacting the molding transfer surfaces of the plurality of glass molded bodies,
A method for manufacturing an optical element, comprising: a cutting step in which the molding transfer surface is brought into contact with the arrangement reference surface and the plurality of glass molded bodies are arranged and fixed in a straight line. The fixing jig has a plurality of the array reference surfaces,
The cutting step is a step of cutting a plurality of parallel cutting lines in a state where the plurality of glass molded bodies are arranged and fixed on a plurality of parallel straight lines. 2. A method for producing an optical element according to 1.   The method of manufacturing an optical element according to claim 2, wherein the fixing jig includes an array member having two array reference surfaces facing each other.   Using a plurality of the fixing jigs that have substantially the same interval between the corresponding array reference planes, the cutting line intervals in the cutting step are the same regardless of which of the plurality of fixing jigs is used. The method for manufacturing an optical element according to claim 2, wherein the optical element is cut as a setting.   The method for manufacturing an optical element according to claim 1, wherein at least one of the optical surfaces is a cylindrical surface.   6. The optical element manufacturing method according to claim 1, wherein the optical element is a beam shaping element for shaping an elliptical output beam output from a semiconductor laser into a circular shape. Method.

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