JP4689982B2 - Optical element manufacturing method - Google Patents

Description

  The present invention relates to a method of manufacturing an optical element having an optical functional surface by pressing a glass, and more particularly to a method of manufacturing an optical element in which an antireflection portion for preventing light reflection is formed at the peripheral portion of the optical functional surface. .

  As a method for manufacturing a lens made of glass, a method by polishing and a method by pressing are known. Among these, the manufacturing method of the lens by polishing processing is a lapping process using a free abrasive such as cerium oxide while adhering and fixing a glass material pressed to an approximate shape slightly larger than the finished product, Thereby, an optical functional surface is produced.

  Once the optical functional surface is produced, centering is performed to eliminate the eccentricity of the optical axis from the outer diameter. The centering process is performed by fixing the optical element on which the optical function surface has been manufactured to a centering machine, and grinding the excess portion of the peripheral portion of the optical function surface.

  In addition, the periphery of the optical function surface is painted in order to block stray light. In order to stably adhere this sanitized paint and to attenuate the reflection of stray light, after the optical functional surface is produced, the centering processing machine removes the surplus margin at the peripheral portion of the optical functional surface, It forms on the sliding surface which has surface roughness.

  On the other hand, in a method of manufacturing a lens by pressing, an optical functional surface is produced by heating a lens material called an oval or truncated gob material in a mold and pressing the softened gob material. Thereafter, the peripheral portion of the optical functional surface is formed on a sliding surface having an appropriate surface roughness using a centering machine as in the case of polishing.

That is, it has a process by a centering machine regardless of polishing and pressing. As such a centering machine, there is, for example, one disclosed in Patent Document 1, and in this centering machine, an optical element is fixed to a portion called a bell chuck (bell holder).
Japanese Patent Laid-Open No. 11-156688

  However, in the conventional method of manufacturing an optical element, the peripheral portion for sanitizing and stray light reflection attenuation is performed by grinding the peripheral portion of the optical functional surface with a centering machine. Must be precisely positioned and firmly fixed to withstand grinding forces. For this reason, the centering machine becomes relatively expensive, and the cost for manufacturing the optical element increases.

  And the process by this centering machine is required regardless of whether it is polishing or press working. In the case of press working, the production of the optical functional surface can be performed more easily than the polishing process. On the other hand, it is necessary to perform rough surface processing with a centering machine after press processing. The cost could not be reduced much.

  In press working, the accuracy of the outer diameter can be increased by increasing the accuracy of the mold. Nevertheless, roughing with a centering machine tends to cause a mismatch between the optical axis and the centering axis, and the accuracy of the outer diameter may be adversely affected.

  The present invention has been made in view of the above problems, and when producing an optical functional surface by press working, the peripheral portion of the optical functional surface is highly accurate and inexpensive without performing rough surface processing by a centering machine. An object of the present invention is to provide a method of manufacturing an optical element capable of roughing the surface.

In order to solve the above-described problems, an optical element manufacturing method according to the present invention forms an intermediate member having an optical functional surface by pressing a lens material, and then a peripheral surface on the outer side of the optical functional surface. In the manufacturing method of the optical element having the step of performing the rough surface processing,
The intermediate member is fixed from both sides so as to expose only a peripheral portion outside the optical function surface, and particles are formed on the peripheral surface outside the end portion of the fixed optical function surface. The surface of the peripheral edge portion is roughened by colliding with a shaped abrasive material.

The optical element manufacturing method according to the present invention is a method for manufacturing an optical element in which an optical functional surface is formed by pressing the lens material after subjecting the peripheral surface of the lens material to a rough surface processing. ,
The lens material is fixed from both sides so as to expose only the peripheral edge outside the portion where the optical functional surface is formed, and the end of the portion where the fixed optical functional surface is formed The surface of the peripheral edge, which is the outer side of the optical functional surface of the lens material, is roughened by colliding the surface of the peripheral edge on the outer periphery with respect to the surface.

  Furthermore, the method of manufacturing an optical element according to the present invention is characterized in that the abrasive is jetted simultaneously with gas or liquid or a mixture of gas and liquid from a jet nozzle and collides with the intermediate member or the lens material. ing.

  Furthermore, the method of manufacturing an optical element according to the present invention is characterized in that a plurality of the injection nozzles are provided and the abrasive is injected and collided from a plurality of positions with respect to the intermediate member or the lens material. Yes.

  And the manufacturing method of the optical element which concerns on this invention sprays the liquid for washing | cleaning, maintaining the fixation from both surfaces, after giving a rough surface process to the peripheral part of the said intermediate member or a lens raw material, and the said peripheral part. It is characterized by performing cleaning.

  According to the method for manufacturing an optical element according to the present invention, the intermediate member having the optical function surface is fixed from both sides over the entire circumference at the end of the optical function surface, and more than the end of the fixed optical function surface. By making the abrasive particles collide with the outer surface, by roughing the peripheral surface, the peripheral surface can be uniformly roughened without accurate centering. Therefore, it is possible to easily and accurately rough the surface with an inexpensive apparatus, and to manufacture the optical element at a low cost. In addition, since accurate centering is not required, rough surface processing can be performed even if the optical function surface is a shape close to a flat surface, so that the shape restrictions in manufacturing optical elements can be greatly reduced. Can do.

  Further, according to the method of manufacturing an optical element according to the present invention, the lens material is fixed from both sides over substantially the entire circumference at the end of the portion where the optical functional surface is formed, and the fixed optical functional surface is formed. The surface of the peripheral edge of the lens material can be roughened on the surface of the outer periphery of the lens material by colliding with the surface of the peripheral edge of the lens material. Since the rough surface processing can be performed uniformly, the rough surface processing can be performed easily and with high accuracy by an inexpensive apparatus, and the optical element can be manufactured at low cost.

  Further, according to the method of manufacturing an optical element according to the present invention, the abrasive is jetted simultaneously with gas or liquid or a mixture of gas and liquid from the jet nozzle, and collides against the intermediate member or the lens material, whereby the abrasive is It can collide with the peripheral part of an intermediate member or a lens member equally efficiently.

  Furthermore, according to the method for manufacturing an optical element according to the present invention, a plurality of injection nozzles are provided, and abrasives are injected and collided from a plurality of positions with respect to the intermediate member or the lens material, respectively. The injection pressure with respect to the intermediate member or the lens material can be canceled, and the influence of misalignment can be almost eliminated.

  According to the method for manufacturing an optical element according to the present invention, after the rough surface processing is performed on the peripheral portion of the intermediate member or the lens material, the cleaning liquid is sprayed while the fixing from both surfaces is maintained. By performing the cleaning, the rough surface processing and the cleaning can be easily performed continuously, and the manufacturing cost can be further reduced.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view of the lens material 1, and FIG. 2 is a side view of the completed optical element 3. The optical element 3 of the present embodiment includes optical functional surfaces 10 and 10 on both sides, and a peripheral edge 11 is formed around the optical functional surfaces 10 and 10 and is formed by pressing a glass. As shown in FIG. 1, an optical element 3 shown in FIG. 2 is formed by preparing a lens material 1 called a gob material previously formed into an elliptical shape, heating and softening it, and pressing it with a mold. .

  The gob material which is the lens material 1 can be made into a predetermined shape by dropping an appropriate amount of a glass material in a softened state from a glass melting furnace and changing the shape of the receptacle. In the present embodiment, an elliptical shape as shown in FIG. 1 is shown, but other shapes such as a wharf shape can also be used. Moreover, you may press-work using the lens raw material 1 which consists of glass of cylindrical shape etc. instead of a gob material.

  As shown in FIG. 2, the completed optical element 3 is a rough surface in which the surface of the peripheral edge 11 of the optical functional surface 10 is formed with a number of fine recesses, and is further sanitized. Thus, the stray light entering from the peripheral portion 11 is blocked and only the light passing through the optical function surface 10 can be taken out.

  FIG. 3 is a flowchart showing manufacturing steps of the optical element 3 in the present embodiment. First, a lens material 1 made of gob material is prepared (S1). Next, the lens material 1 is placed in a mold and heated and pressed (S2). Thus, the intermediate member 2 having the optical function surface 10 is formed. Thereafter, the intermediate member 2 is removed from the mold, and the rough surface processing of the peripheral edge portion 11 is performed (S3). Details of this will be described later.

  For the intermediate member 2 subjected to the rough surface processing, the peripheral edge 11 is cleaned (S4), and an antireflection film is formed on the peripheral edge 11 (S5). Further, the intermediate member 2 is cleaned (S6), and finally, blacking is applied to the peripheral edge portion 11 (S7). Since a large number of concave portions are formed on the peripheral edge portion 11 by roughening, it is easy for ink paint to adhere to the peripheral portion 11, and it is possible to further prevent the intrusion of stray light by scattering the reflected light.

  FIG. 4 is a schematic diagram showing steps from the lens material to the rough surface processing in the present embodiment. 4A shows a state in which the lens material 1 made of gob material is prepared, that is, the state of S1 in FIG. 3, and FIG. 4B shows a state in which pressing is performed by the mold 20, that is, the state of S2 in FIG. Show. FIG. 4c shows a state where the peripheral surface 11 is roughened, that is, the state of S3 in FIG.

  The mold 20 used in the press work of FIG. 4b is composed of an upper mold 21 and a lower mold 22, and the upper mold 21 and the lower mold 22 are formed in a shape obtained by inverting the shape of the optical element 3, respectively. Molded surfaces 21a and 22a are formed. The upper mold 21 and the lower mold 22 are arranged so that the molding surfaces 21a and 22a face each other, the lens material 1 is arranged between them, the glass is heated to soften the glass, and then pressed. The intermediate member 2 having the optical functional surfaces 10 and 10 on both sides is formed.

  After the intermediate member 2 is formed by pressing, the intermediate member 2 is removed from the mold 20 and fixed to the fixed chuck 23 as shown in FIG. 4c. The fixing chuck 23 fixes the intermediate member 2 from both sides at the end of the optical function surface 10 over substantially the entire circumference, and only the peripheral edge 11 is exposed to the outside. The center line of the fixed chuck 23 and the center line of the intermediate member 2 are aligned by being arranged so that the center of the optical function surface 10 is on the center line of the fixed chuck 23.

  In this state, by rotating the fixed chuck 23 around the center line, the particulate abrasive 30 is transferred from the injection nozzle 24 to the peripheral edge 11 of the intermediate member 2 while rotating the intermediate member 2 in the circumferential direction. Spray. The particulate abrasive 30 collides with the peripheral edge 11 of the intermediate member 2 and scrapes the surface to form fine recesses. As a result, the surface of the peripheral edge 11 is roughened.

  As the abrasive 30, silicon oxide, aluminum oxide, or the like is used. However, any other material may be used as long as it is used as an abrasive. Further, dry ice or ice containing an abrasive may be used. Furthermore, you may use what contained the abrasives in elastic bodies, such as rubber | gum.

  The surface roughness of the peripheral portion 11 may be 1 μm or more as long as it is only for preventing the reflection of the surface of the peripheral portion 11, but is 2 μm or more in order to improve the adhesion of the paint in the inking process. It is desirable. In practice, it is appropriate to have a surface roughness of about 2 μm to 10 μm. In this case, the particle size of the abrasive 30 is about 30 μm to 80 μm. If the surface roughness is 10 μm or more, the uneven shape remains on the surface of the peripheral edge portion 11 even after sanitization, which causes an aesthetic problem. However, this is not a problem in terms of functionality.

  Further, in order to efficiently inject the abrasive 30 from the injection nozzle 24, the abrasive 30 is injected together with gas, liquid, or a mixture of gas and liquid. The process of cutting or roughening the surface by jetting the particulate abrasive 30 from the injection nozzle 24 and causing the abrasive 30 to collide with the processed surface is generally called blasting.

  A plurality of spray nozzles 24 may be provided. In this case, by arranging the injection nozzles 24 and 24 so that the angles formed with each other are equal, the force applied to the intermediate member 2 by the injection of the abrasive 30 can be canceled, and the intermediate member 2 can be fixed. Even if there is misalignment, the force in the direction of misalignment can be reduced.

  Even if the center line of the intermediate member 2 and the center line of the fixed chuck 23 are not accurately aligned by causing the abrasive abrasive 30 to collide with the peripheral edge 11 of the intermediate member 2 and performing the rough surface processing, There is no hindrance to the rough surface processing, and therefore the rough surface processing can be easily performed without using a conventional centering machine.

  Further, the entire outer shape of the peripheral portion 11 is scraped off from the surface by about 10 μm due to the collision of the abrasive 30, so that the surface of the paint and the optical function surface 10 can be made substantially flush with each other when an inked paint is applied. Thus, the appearance of the optical element 3 can be improved.

  The cleaning step of S4 in FIG. 3 can be performed as it is in the state shown in FIG. 4C, that is, in a state where the intermediate member 2 is fixed to the fixed chuck 23. That is, after performing the rough surface processing of S3 in FIG. 3, while the intermediate member 2 is fixed by the fixed chuck 23 in the same apparatus, the cleaning liquid is sprayed from the spray nozzle 24 that sprays the abrasive 30, The peripheral portion 11 is cleaned by

  Further, in this cleaning process, the fixed chuck 23 is slightly opened, and a cleaning liquid is allowed to flow from the central portion of the fixed chuck 23 so that not only the peripheral portion 11 but also the device in the vicinity of the fixed chuck 23 is used. And the intermediate member 2 can also be cleaned.

  Next, a second embodiment of the present invention will be described. FIG. 5 is a flowchart showing a manufacturing process of the optical element in the present embodiment. As shown in this figure, first, a lens material 1 made of gob material is prepared (S1). Then, roughening is performed in the state of the lens material 1 (S2). Next, after cleaning (S3), the intermediate member 2 having a roughened peripheral edge portion 11 is placed in a mold and heated to perform pressing (S4). The subsequent steps are the same as those in the first embodiment.

  FIG. 6 is a schematic diagram illustrating steps from the state of the lens material 1 in the present embodiment to pressing. 6A shows a state in which the lens material 1 made of gob material is prepared, that is, the state of S1 in FIG. 5, and FIG. 6B shows a state in which roughening is performed on the peripheral portion 11 of the lens material 1, that is, The state of S2 of FIG. 5 is shown. Moreover, FIG. 6c has shown the state which is pressing with respect to the intermediate member 2, ie, the state of S4 of FIG.

  As shown in FIG. 4b, the lens material 1 is fixed to the same fixed chuck 23 as in the first embodiment in order to perform the rough surface processing on the peripheral edge portion 11 of the lens material 1. Here, the fixing chuck 23 is fixed from both sides over substantially the entire circumference at the end portion of the lens material 1 where the optical functional surface 10 is formed. Therefore, the lens material 1 fixed to the fixing chuck 23 is in a state where only the peripheral edge 11 outside the portion where the optical function surface 10 is formed is exposed. In this state, the fixed chuck 23 and the lens material 1 are rotated around the center line, the abrasive 30 is sprayed from the spray nozzle 24 toward the peripheral portion 11, and the abrasive 30 is collided with the surface of the peripheral portion 11. Roughening is performed.

  In the present embodiment, since the press working is performed after the rough surface processing, it is necessary that the peripheral edge portion 11 can maintain the rough surface even by the press processing. Therefore, the abrasive 30 having a larger particle diameter than that of the first embodiment is used. Specifically, an abrasive 30 that has a surface roughness of about 3 to 4 times that in the case of the first embodiment is used. However, if the surface roughness is too large, glass powder is likely to be generated when the intermediate member 2 is handled. Therefore, the surface roughness is set with an upper limit of about 20 μm. Moreover, in the press work shown in FIG. 6c, in order to maintain the rough surface state of the peripheral edge portion 11, the pressing is performed under conditions of lower temperature and lower pressure than usual.

  As described above, even when the rough surface processing is performed at the stage of the lens material 1, even if the center line of the lens material 1 and the center line of the fixed chuck 23 are not accurately aligned as in the first embodiment, There is no hindrance to the rough surface processing, and therefore the rough surface processing can be easily performed without using a conventional centering machine, so that an inexpensive optical element can be obtained.

  Further, even when the shape of the gob material is close to a flat surface, the lens material 1 can be rotated and its outer shape can be used to create a vibration-free state, which can be fixed by the fixing chuck 23 from both sides. The restriction on the shape of the lens material 1 can be reduced.

  Furthermore, as in the first embodiment, a plurality of injection nozzles 24 are provided, and the angles formed by the injection nozzles 24 are equal to each other, so that the force applied in the misalignment direction of the lens material 1 is increased. Can be small.

  As mentioned above, although embodiment of this invention was described, application of this invention is not restricted to these embodiment, It can apply variously within the range of the technical idea.

It is a side view of a lens material. It is a side view of the completed optical element. It is the flowchart which showed the manufacturing process of the optical element in this embodiment. It is the schematic diagram which showed the process until it gives a rough surface process from the state of the lens raw material in this embodiment. It is the flowchart which showed the manufacturing process of the optical element in 2nd Embodiment. It is the schematic diagram which showed the process until it press-processes from the state of the lens raw material in 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens material 2 Intermediate member 3 Optical element 10 Optical functional surface 11 Peripheral part 20 Mold 23 Fixed chuck 24 Injection nozzle

Claims (5)

In the method of manufacturing an optical element having a step of forming an intermediate member having an optical functional surface by pressing a lens material, and thereafter performing a rough surface processing on a peripheral surface outside the optical functional surface,
The intermediate member is fixed from both sides so as to expose only a peripheral portion outside the optical function surface, and particles are formed on the peripheral surface outside the end portion of the fixed optical function surface. A method for producing an optical element, characterized in that a rough surface treatment is applied to the peripheral surface by colliding a shaped abrasive. In the method of manufacturing an optical element that forms an optical functional surface by pressing the lens material after roughening the peripheral surface of the lens material,
The lens material is fixed from both sides so as to expose only the peripheral edge outside the portion where the optical functional surface is formed, and the end of the portion where the fixed optical functional surface is formed by impinging particulate abrasive outside the peripheral surface than the section, method of manufacturing an optical element characterized by applying roughening on the periphery surface which is outside of the optical function surface of the lens material .   3. The method of manufacturing an optical element according to claim 1, wherein the abrasive is jetted simultaneously with gas or liquid or a mixture of gas and liquid from a jet nozzle and collides with the intermediate member or the lens material.   4. The method of manufacturing an optical element according to claim 3, wherein a plurality of the injection nozzles are provided, and the abrasive is injected and collided with the intermediate member or the lens material from a plurality of positions.   5. The peripheral portion is cleaned by spraying a cleaning liquid while maintaining the fixation from both sides after roughening the peripheral portion of the intermediate member or lens material. The manufacturing method of the optical element of any one of these.

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