JPS6067132A - Forming method of optical element - Google Patents

Abstract

PURPOSE:To obtain an optical element excellent in precision etc. in a short time, by setting an optical material on a die having a desired curved surface and a plurality of through-holes directed from said curved surface to a surface on the opposite side, and by sucking the optical material to the curves surface through the through-holes. CONSTITUTION:A die 4 which has a curved surface 4a shaped in a non-spherical or spherical surface and a plurality of through-holes 4b directed from the curved surface 4a to a surface 4c on the opposite side to the curved surface 4a is held by a holding member 6. Then, an optical material 8 formed of plastic or glass material is set on the die 4, sucked from a suction hole 6b of the holding member 6, and changed in shape along the curved surface 4a. Next, the parts of curved surfaces 8a1 and 8a2 at the top of the optical material 8 are cut away, and then the optical material 8 is taken out by releasing the suction. The non- spherical or spherical curved surface thus prepared is subjected to polishing and coating, and whereby the desired optical element is obtained.

Description

[Detailed Description of the Invention] Conventionally, aspherical lenses and mirrors have been produced by profiling using a tenten rate made in the same ratio as the shape produced by a grinding machine, or by grinding using a numerically controlled grinding machine. , uniform polishing was performed using an elastic polishing sheet or the like. Furthermore,
After deforming the lens 2 using a ring-shaped receiver 1 and vacuum force as shown in Figure 1, polishing is performed on a spherical or flat surface. There were also ways to try to achieve this.

However, the mechanical grinding method not only requires an expensive grinding machine with high precision and high precision, but also an expensive aspherical shape measuring machine with high measurement accuracy. Processing and measurement had to be carried out for each workpiece, which resulted in high costs and insufficient accuracy in shape measurement, making it impossible to manufacture highly accurate optical elements. There is also a method of deforming the workpiece by receiving it with a ring.
Complex shapes whose deformation amount varies widely depending on the strength of the vacuum force cannot be created. Also, it is not easy to measure whether the shape of the ring that receives the workpiece is manufactured with high precision.
It has been impossible to stably produce optical elements.

The present invention has been developed in consideration of the above-mentioned conventional problems, and is capable of accurately processing into a desired aspherical or spherical surface when forming an optical element that requires a curved surface of one aspherical surface, such as a lens filter or a light flux antireflection film. It is an object of the present invention to provide a processing method that can shorten the time required to produce one or ten pieces.

FIGS. 2(a) to 2(d) show an apparatus according to an embodiment of the present invention.

Reference numeral 4 indicates a mold, and the mirror mold is a disk or a flat plate depending on the shape of the optical element. One surface 4a ( ) of the mirror shape is finished as an aspherical or spherical curved surface.

When the optical element is a lens, the curved surface 4a is finished into a predetermined aspherical or spherical surface calculated geometrically or mathematically.

The mold 4 is provided with a plurality of through holes 4b, and the through holes 4b extend from the curved surface 4a to the surface 4 opposite to the curved surface 4a.
Install parallel to C.

4d1, 4d2, 4dg... indicate grooves formed concentrically on the curved surface 4a of the mold, the grooves are formed above the through hole 4b, and 4e1, 4e2... indicate approximately 4 da. These are grooves on the curved surface 4a provided so as to intersect with each other.

Reference numeral 6 denotes a holding member that holds the mold 4 and sucks it. The holding member 6 is a holding portion 6a that stores and holds the mold 4.
and a suction port 6b.

FIG. 2(C) is a diagram showing the process of making an optical element using the apparatus shown in FIGS. The element material 8 is placed on the upper part of the mold 4 and sucked through the suction port 6b of the holding member 6.

The lower surface 4C of the hood 4 is supported at a point so as to rise slightly above the holding surface 6C of the holding member 6, thereby forming a passage for sucking air.

The element material 8 sucked along the aspherical or spherical surface of the curved surface 4a of the mold 40 deforms within an elastic deformation as shown in FIG. 2(C)K.

The upper surface of the element material 8 that has been sucked, that is, the upper surface of the element material 8 shown in FIG. 2 (C12
Cut the portions 8at and 8a2 indicated by the dotted chain lines 01-02.

After that, the suction is released and the element material 8 is taken out.
), the optical element having a curved surface having an aspherical or spherical shape is formed by cutting off the 8a1 and 882, and then the curved surface is polished and coated to finish the optical element.

The inner mold 4 may be flat and the grooves may be intersecting grooves as shown in FIG. In addition, as a method of deforming and tightly fixing the workpiece, you can use not only a vacuum but also an adhesive 10 as shown in Figure 4. It is possible to fix the workpiece mechanically from the outside.The workpiece is not limited to glass, but can also be made of metal or other non-metallic materials.Also, the processing of closely fixed workpieces is not limited to spherical or flat surfaces, but can also be done on non-metallic surfaces. It is also possible to process a spherical surface.

As described above, according to the present invention, by providing a plurality of through holes 4b in the curved surface of the mold 40 and employing a method of sucking the optical element material through the through holes, it is possible to hold the optical element material in close contact with each part of the curved surface. The curved surface of the mold can be accurately transferred to the surface of the material.

Furthermore, by employing the above method, an aspherical or spherical surface can be formed accurately in a single suction operation, thereby increasing mass productivity.

[Brief explanation of the drawing]

FIGS. 1(a), (b), and (C) are diagrams showing examples of conventional methods. FIGS. 2(a), (b), (C) and (d) show embodiments of the present invention. ＃I death door 蔗 liver side M. FIG. 2(C) is an explanatory diagram of the operation of the apparatus, and FIG. 2(d) is a diagram showing an example of a finished optical element. FIG. 6 is a perspective view of another example. FIG. 4(a) is a diagram showing another example of fixing the element material 8 to the mold 4. FIG. 4(b) is a sectional view of the element taken out from the screen of FIG. 4(a).

Claims (1)

[Claims] (1) A mold having an aspherical or spherical curved surface and a plurality of through holes extending from the curved surface to the surface opposite to the curved surface, and an optical material made of plastic or glass material on the upper surface of the mold. The optical material is placed on one side of the mold through the through hole, and the optical material is sucked onto the curved surface of the mold, and the upper surface of the optical material immersed in the curved surface of the mold is removed. An optical element forming method characterized by forming a spherical surface or a spherical shape.