JP2009073735A - Method for producing holder-fitted optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a high precision holder-fitted optical element where the volume error of an optical element stock is made correctable, and the error in the shape of a holder is reduced. <P>SOLUTION: An almost cylindrical holder stock 30a in which the upper and lower edge faces on the circumferential side thereof are flat face-shaped fitting faces 11, and a thin part 17 is formed between the fitting faces is arranged at the inside of a press molding die 60, the inside of the holder stock 30a is provided with an optical element stock 10a, they are heated to the respective softening temperatures, and the holder stock and the optical element stock are press-molded by a press molding die capable of pressing them, respectively independently, thus the shape of the molding face of the press molding die is transferred to the holder stock 30a and optical element stock 10a, respectively, further, the holder stock 30a is pressed from the inside by the optical element stock 10a, the thin part 17 of the holder stock is deformed toward the outer direction as a deformed part, thus the cylindrical holder 30 is molded from the holder stock 30a, and further, the optical element 10 is molded from the optical element stock 10a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an optical element with a holder in which a holder and an optical element are integrated, and more particularly to a method for manufacturing an optical element with a holder that is formed by press-molding an optical element material in a holder.

  Optical elements such as a lens mounted on a pickup head of a CD player and a lens used in a digital camera are required to have high mounting accuracy. In order to satisfy such a requirement, generally, an optical element with a holder in which the optical element is held by a holder is manufactured, and the mounting accuracy required by the holder is satisfied. As a method for manufacturing such an optical element with a holder, for example, as shown in Patent Document 1, an optical element material is placed inside a cylindrical holder material and heated, and the holder material and the optical element material are then molded using a mold. There is a method in which an optical element is formed by press molding, an attachment surface of the holder is formed, and the optical element is pressed and integrated with the holder.

Japanese Patent No. 2793433 (FIG. 3)

  By the way, when the optical element material is press-molded, if there is a volume error in the optical element material, the thickness of the optical element changes, and the optical performance deteriorates. Fixing is required, causing problems in terms of performance and positioning. As a method of solving this, there is a method of reducing the volume error by improving the accuracy of the material volume of the optical element. However, in order to ensure this effect, it is necessary to finish not only the material volume of the optical element but also the shape of the holder with high accuracy.

  The present invention has been made in view of the above problems, and provides a method for manufacturing a high-accuracy optical element with a holder that can correct a volume error of an optical element material and has a small error in the shape of a holder. With the goal.

  In order to solve the above-mentioned problems, the present invention has a substantially cylindrical shape, and the upper and lower end surfaces of its circumferential side surface are flat mounting surfaces, and a holder material in which a thin portion is formed between the mounting surfaces is press-molded. A press mold that is placed in a mold, provided with an optical element material inside the holder material, heated to the respective softening temperatures, and each of the holder material and optical element material heated to the softening temperature can be independently pressed. By press molding, the shape of the molding surface of the press mold is transferred to each of the holder material and the optical element material, and the holder material is pressed from the inside by the optical element material, so that the thin portion of the holder material is formed. As a deforming portion, it is deformed outward, and a cylindrical holder is formed from the holder material and an optical element is formed from the optical element material.

  Further, the present invention is characterized in that the reference mounting surface in the optical axis direction and the radial direction of the optical element with the holder is formed on the holder outer shape by press molding of the holder material.

  Further, the present invention is characterized in that a surplus is previously added to the volume of the optical element material necessary for forming the optical element, and the deformed portion is deformed by the surplus.

As described above, according to the present invention, a holder material having a substantially cylindrical shape, the upper and lower end surfaces of the circumferential side surface being flat mounting surfaces, and a thin portion formed between the mounting surfaces is disposed in the press mold. Then, an optical element material is provided inside the holder material, heated to each softening temperature, and each of the holder material and the optical element material heated to the softening temperature is press-molded with a press mold that can be pressed independently. Therefore, it is possible to manufacture a holder with higher accuracy than in the case of forming by cutting or the like.
In addition, since the optical element is integrated inside the holder by press-molding the holder and the optical element at the same time, the positional relationship between the holder and the optical element can be matched with the design value with high accuracy. No need to adjust the position when mounting.
Furthermore, since the holder material is pressed from the inside by the optical element material and deforms outward using the thin portion of the holder material as a deformed portion, the volume error of the optical element material is deformed during molding of the optical element. Since the portion is absorbed by deformation, an optical element with a holder having an optical element of a desired shape with high molding accuracy can be manufactured.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view of an optical element with a holder in the first embodiment of the present invention, FIG. 2 is a sectional view of a lens holder material and a lens material in the first embodiment of the present invention before press molding, and FIG. Sectional drawing of the manufacturing apparatus in 1st embodiment of invention, FIG. 4 is sectional drawing which shows the manufacture state of the optical element with a holder in 1st embodiment of this invention.
The optical element 1 with a holder in the present embodiment is used for, for example, a pickup head of a CD player, a digital camera, etc. As shown in FIG. 1, a cylindrical lens holder 10 and an inner side of the lens holder 10 The spherical lens 20 is housed in the lens.

  The lens holder 10 holds the lens 20 and is used for positioning the lens 20 in an optical device, and is made of aluminum or stainless steel. The lens holder 10 has mounting surfaces 11 and 11 as reference surfaces in the optical axis direction when attached to an optical device, an inner peripheral surface 12 with which the lens 20 abuts, and an outer peripheral surface as a radial reference surface when attached to an optical device. 13 On the inner peripheral side of the lens holder 10, a thin deformed portion 17 constituting the central portion of the inner peripheral surface 12 is formed, and an end portion of the inner peripheral surface 12 is continuous with the deformed portion 17. And the inner peripheral attachment part 14 which comprises a part of attachment surface 11 is formed. Further, an outer peripheral attachment portion 15 constituting an end portion of the outer peripheral surface 13 and a part of the attachment surface 11 is formed on the outer peripheral side of the lens holder 10, and the outer peripheral attachment portion 15 is deformed by a connecting portion 16. The outer peripheral space 18 is formed on the outer peripheral side of the deformable portion 17 so as to be surrounded by the deformable portion 17 and the connecting portion 16.

  Here, the lens holder 10 is formed by forming a lens holder material 10a having a deformed portion 17 as shown in FIG. 2 with a certain degree of dimensional accuracy by a cutting method, a casting method or the like, and press-molding this. . Thus, by forming the lens holder 10 finally by press molding, the lens holder 10 can be made with higher accuracy than when formed by cutting or the like.

  A glass lens 20 is housed inside the lens holder 10. The lens 20 is a spherical convex lens on both sides, and is formed by press molding a lens material 20a shown in FIG. Further, it is pressed against the lens holder 10 by pressure during press molding and integrated with the lens holder 10. The peripheral portion 21 of the lens 20 has a surplus portion 21a protruding outward from the substantially entire surface thereof.

  The lens material 20a described above is made of an optical glass material. As the optical glass material, for example, there is a lead oxide glass material SFS01. Here, the lens material 20a intentionally has a surplus in addition to the volume necessary to form the lens 20. By doing so, the volume error of the conventional lens material 20a is included in this surplus, and at least the volume of the lens material 20a necessary for molding the lens 20 is secured.

  Here, in the stage of the lens holder material 10a before press molding formed by cutting or the like, the lens holder 10 has a deformed portion 17 substantially perpendicular to the mounting surfaces 11 and 11, as shown in FIG. Is formed. However, due to the molding pressure when the lens 20 is press-molded, the surplus portion of the lens material 20a pushes the deformed portion 17 radially outward, and the lens holder material 10a is press-molded, whereby the deformed portion 17 Is deformed into a shape warped radially outward, that is, toward the outer peripheral space 18 side. Then, all the surplus portion of the lens material 20a is accommodated in the space formed inside the deformation portion 17 by the deformation of the deformation portion 17. That is, the surplus that is a volume that is unnecessary for the formation of the lens 20 in the lens material 20a is absorbed by the deformation of the deformation portion 17 together with the volume error. This makes it possible to mold the lens 20 having a desired shape with high molding accuracy.

  By the way, when the rigidity of the deformable portion 17 is high, the deformable portion 17 is not easily deformed, and is not deformed by the excessive pressing force of the lens material 20a and the molding pressure on the lens holder material 10a. It becomes an error. Conversely, if the rigidity of the deforming portion 17 is low, it is easily deformed by the molding pressure on the lens holder material 10a and the pressing force of the lens material 20a when the molding pressure is applied, and is necessary for absorbing the surplus. It will be deformed beyond the amount of deformation. If the rigidity is small, the shape of the lens holder 10 cannot be maintained. That is, the rigidity of the deformable portion 17 needs to be large enough to be deformed to absorb the surplus portion of the lens material 20a but not to be deformed beyond that. With respect to the rigidity of the deformable portion 17, the deformable portion 17 can be made to function more appropriately by selecting a thickness, material, or the like that satisfies such conditions.

  Next, the manufacturing apparatus which manufactures such an optical element 1 with a holder is demonstrated. As shown in FIG. 3, the manufacturing apparatus 60 includes an upper mold A, a lower mold B, and an outer diameter mold C. The upper mold A includes an inner upper mold 61 and an outer upper mold 62, and the lower mold B located on the lower side of the upper mold A includes an inner lower mold 63 and an outer lower mold 64. Further, an outer diameter mold C is provided so as to surround the upper mold A and the lower mold B.

The inner upper die 61 and the inner lower die 63 are formed in a substantially cylindrical shape, and lens transfer surfaces 61 a and 63 a for forming a spherical lens surface are formed on the lower end portion of the inner upper die 61 and the upper end portion of the inner lower die 63. Has been. On the other hand, the outer upper die 62 and the outer lower die 64 are positioned on the outer peripheral side of the inner upper die 61 and the inner lower die 63, respectively. The outer upper mold 62 and the outer lower mold 64 are formed in a circular tube shape, and a holder molding surface 62a for molding the mounting surface of the lens holder 10 on the lower end portion of the outer upper mold 62 and the upper end portion of the outer lower mold 64, 64a is formed. The thickness of the outer upper mold 62 and the outer lower mold 64 is substantially equal to the thickness of the lens holder 10 described above, and the inner periphery of the outer diameter mold C is substantially equal to the outer diameter of the lens holder 10.
Further, the inner upper die 61 and the outer upper die 62 can slide up and down independently by a driving mechanism (not shown). On the other hand, the inner lower die 63 and the outer lower die 64 are in a fixed state. However, the inner lower mold 63 and the outer lower mold 64 may also be slidable up and down.

  Hereinafter, the process of manufacturing the optical element 1 with a holder using the manufacturing apparatus 60 will be described. First, as shown in FIG. 4A, the lens holder material 10 a is placed on the holder molding surface 64 a of the outer lower mold 64. This lens holder material 10a is previously processed into a cylindrical shape with a certain degree of dimensional accuracy. Further, the lens material 20a is placed inside the lens holder material 10a.

Here, although omitted in FIG. 4, a heating member is opposed to the outer periphery of the lens holder material 10a, and the lens holder material 10a is heated to the softening temperature by the heating member. As a result, the inner lower die 63 and the outer lower die 64 are also heated.
On the other hand, the lens material 20a is heated by the radiant heat of the outer lower mold 64, and the transmitted heat and radiant heat of the lens holder material 20a and the inner lower mold 63. The temperature of the glass material 20a during the heating is heated to a temperature that is approximately 30 degrees lower than the softening temperature of the lens holder material 10a. And this temperature is the softening temperature of the glass raw material 20a, for example, is a temperature near a glass transition point between a glass transition point and a glass softening point.

  In other words, the lens material 20a that is most suitable for the purpose of use is selected, and the temperature that is optimal for press molding is set within the temperature range between the glass transition point and the glass softening point of the lens material 20a. The material of the lens holder material 10a having a softening temperature is determined. That is, in order to heat the lens material 20a to a predetermined temperature between the glass transition point and the glass softening point, the softening temperature is about 30 degrees higher than the predetermined temperature as the material selection condition of the lens holder material 10a. It is necessary to select the material.

When the lens holder material 10a and the lens material 20a reach the softening temperature in this way, as shown in FIG. 4B, press molding is performed on the lens holder material 10a and the lens material 20a. Specifically, the inner upper die 61 and the outer upper die 62 are moved downward by the driving mechanism. By this movement, the shape of the lens holder material 10 a on the outer lower mold 64 is transferred by the holder molding surface 62 a of the outer upper mold 62 and the holder molding surface 64 a of the outer lower mold 64. That is, the holder forming surfaces 62a and 64a form the attachment surfaces 11 and 11 as reference surfaces in the optical axis direction when attaching to the optical apparatus.
At this time, the molding pressure of the outer upper mold 62 and the outer lower mold 64 causes the inner peripheral mounting portion 14 to shrink in the compression direction on the inner peripheral side of the lens holder material 10a, and at the same time, the deforming portion 17 moves radially outward. Deform. On the other hand, on the outer peripheral side, the connecting portion 16 and the outer peripheral mounting portion 15 bend in the compression direction. In this way, the lens holder element 10a receives the molding pressure of the outer upper mold 62 and the outer lower mold 64 without waste.

  The lens material 20a is transferred with the contour shape of the lens 20 by the lens transfer surface 61a of the inner upper die 61 and the lens transfer surface 63a of the inner lower die 63. Here, since the lens 20 is press-molded simultaneously with the lens holder 10, the positional relationship between the lens 20 and the mounting surfaces 11, 11 and the outer peripheral surface 13 as reference surfaces formed on the lens holder 10 is designed with high accuracy. It is molded in a state that matches the value, and the axis center of the lens holder 10 and the optical axis direction of the lens 20 are also molded in a state that matches with high accuracy.

Further, when the lens material 20a is press-molded and pressurized, the surplus portion of the lens material 20a is squeezed outwardly in the radial direction by this molding pressure and is accommodated inside the lens holder 10a. It becomes the surplus part 21a. Here, the deforming portion 17 is deformed to the outside in the radial direction to some extent by the molding pressure applied to the lens holder material 10a by the outer upper die 62 and the outer lower die 64, and the final pressing force of the lens material 20a finally Therefore, the amount of deformation is deformed so that the entire surplus amount can be accommodated inside the deformation portion 17.
Furthermore, when the deforming portion 17 is deformed in a shape that warps radially outward in this manner, the outer peripheral mounting portion 15 that is continuous with the deforming portion 17 via the connecting portion 16 also moves radially outward. The outer peripheral attachment portion 15 is pressed against the outer diameter mold C. Thus, the outer peripheral surface 13 is formed as a radial reference surface when attached to the optical apparatus.

The first embodiment of the present invention has been described above. Next, a second embodiment of the present invention will be described. FIG. 5 is a cross-sectional view of the optical element with a holder in the second embodiment of the present invention, FIG. 6 is a cross-sectional view of the lens holder material and the lens material in the second embodiment of the present invention before press molding, and FIG. It is sectional drawing which shows the manufacture state of the optical element with a holder in 2nd embodiment of invention.
As in the first embodiment, the optical element 2 with a holder in the present embodiment is used for, for example, a pickup head of a CD player, a digital camera, etc. As shown in FIG. The lens holder 30 includes a spherical lens 40 that can be accommodated inside.

  The lens holder 30 is made of aluminum, stainless steel, or the like, and has mounting surfaces 31, 31, an inner peripheral surface 32, and an outer peripheral surface 33. One mounting surface 31 is configured by an outer peripheral mounting portion 34 that is formed in a convex shape on the outer peripheral side, and the inner peripheral side of the outer peripheral mounting portion 34 is at a position that is substantially the same position as one lens surface of the lens 40. In addition, a thin flange 36 is formed with a filling groove 35 interposed therebetween. The flange portion 36 is deformed so that the tip portion is warped outward. Such a lens holder 30 is formed by press-molding a lens holder material 30a formed with a certain degree of dimensional accuracy by a cutting method, a casting method or the like as shown in FIG.

A glass lens 40 is housed inside the lens holder 30. The lens 40 is a spherical convex lens on both sides, and is formed by press molding a lens material 40a shown in FIG. Further, it is pressed against the lens holder 30 by pressure during press molding and integrated with the lens holder 30. This lens 40 has a filling convex portion 41 that fits in the above-described filling groove 35 in a part of the outer peripheral portion. Further, a surplus portion 41 a is formed in the vicinity of the tip portion of the flange portion 36 of the filling groove 35.
Similar to the first embodiment, the lens material 40a intentionally has a surplus in addition to the volume necessary to form the lens 40. In the present embodiment, the volume necessary for forming the lens 40 includes the filling convex portion 41.

  Here, in the initial state in which the lens holder 30 is formed by cutting or the like, as shown in FIG. 6, the flange portion 36 is formed in a planar shape. However, the lens material 40a flows into the filling groove 35 due to the molding pressure when the lens 40 is press-molded, and the excess portion of the lens material 40a pushes the flange 36 from the inside to the outside from the inside of the filling groove 35. As a result, the vicinity of the front end portion of the collar portion 36 is bent outward, and the filling groove 35 is expanded, and all the surplus portion of the lens material 40a is accommodated in the expanded portion. Thereby, the surplus which is a volume integral unnecessary for the formation of the lens 40 in the lens material 40a is absorbed by the deformation of the collar portion 36 together with the volume error, and the lens 40 having a desired shape with high molding accuracy can be molded. It becomes possible. In addition, the request | requirement, such as rigidity with respect to the collar part 36, is the same as that of said 1st embodiment.

Hereinafter, the process of manufacturing the optical element 2 with a holder will be described. Since the manufacturing apparatus 60 is the same as that of the first embodiment, a description thereof will be omitted. First, the lens holder material 30 a is placed on the holder molding surface 64 a of the outer lower mold 64. Further, the lens material 40a is placed inside the lens holder material 30a (FIG. 7A). At this time, the lens holder material 30a is placed with the surface having the flange 36 facing the outer lower mold 64 side.
Thereafter, the lens holder material 30a and the lens material 40a are heated, and when the lens holder material 30a and the lens material 40a reach the softening temperature, press molding is performed on the lens holder material 30a and the lens material 40a (FIG. 7 ( b)), mounting surfaces 31, 31 and an outer peripheral surface 33 are formed on the lens holder material 30a. A lens 40 is also formed.
Further, when the lens material 40a is pressurized, the lens material 40a flows into the filling groove 35 by this molding pressure, and the excess portion of the lens material 40a pushes the flange 36 from the inside to the outside of the filling groove 35. The surplus portion of the lens material 40a is accommodated in the expanded portion of the filling groove 35 formed by this deformation, and this becomes the surplus portion 41a.

  The embodiment of the present invention has been described above. In the above embodiment, the manufacturing method in the case of a spherical convex lens has been described as an example. However, the present invention is not limited to such a lens, and may be a lens having another shape such as a concave lens. Further, the present invention is not limited to a lens, and the method for manufacturing an optical element with a holder according to the present invention can be applied to other optical elements such as a diffraction grating that is integrally accommodated in a holder.

It is sectional drawing of the optical element with a holder in 1st embodiment of this invention. It is sectional drawing of the lens holder raw material and lens raw material in 1st embodiment of this invention before press molding. It is sectional drawing of the manufacturing apparatus of the optical element with a holder in 1st embodiment of this invention. It is sectional drawing which shows the manufacture state of the optical element with a holder in 1st embodiment of this invention. It is sectional drawing of the optical element with a holder in 2nd embodiment of this invention. It is sectional drawing of the lens holder raw material and lens raw material in 2nd embodiment of this invention before press molding. It is sectional drawing which shows the manufacture state of the optical element with a holder in 2nd embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Optical element with a holder 10 Lens holder 10a Lens holder material 17 Deformation part 20 Lens 20a Lens material 21 Peripheral part 21a Surplus part 30 Lens holder 30a Lens holder material 35 Filling groove 36 Gutter part 40 Lens 40a Lens material 41 Filling convex part 41a Surplus part 60 Manufacturing equipment

Claims (3)

It is substantially cylindrical, and the upper and lower end surfaces of its circumferential side surface are flat mounting surfaces, and a holder material in which a thin portion is formed between the mounting surfaces is placed in a press mold, and the holder material Optical element material is provided on the inside, heated to the softening temperature of each,
By pressing the holder material and optical element material heated to the softening temperature with a press mold that can be pressed independently, the shape of the molding surface of the press mold is transferred to each of the holder material and optical element material. In addition, the holder material is pressed from the inside by the optical element material and deformed outward with the thin portion of the holder material as a deformed portion to form a cylindrical holder from the holder material and from the optical element material A method for manufacturing an optical element with a holder, comprising molding an optical element.   2. The method of manufacturing an optical element with a holder according to claim 1, wherein a mounting reference surface in the optical axis direction and the radial direction of the optical element with a holder is formed on a holder outer shape by press molding of the holder material.   3. The optical element with a holder according to claim 1, wherein a surplus is added to the volume of the optical element material in advance to form the optical element, and the deformed portion is deformed by the surplus. Production method.

Images