CN1140819C - Method for manufacturing plate-shaped optical element - Google Patents

Abstract

A method for manufacturing plate-shaped optical element includes such steps as providing a metal substrate, polishing its surface to needed surface roughness, etching the metal substrate, carving the optical pattern on the metal substrate, and filling optical plastic material in the mould while using the etched metal substrate as mould core.

Description

Manufacturing method of plate optical element

The invention relates to a method for manufacturing a plate-shaped optical element. The method uses a metal material as a master mold to manufacture the plate-shaped optical element.

Plate optical elements such as lenticular lenses in projector systems, light guide elements in large backlight panels, microarray focusing lenses in CCD systems, etc. As far as its manufacturing method is concerned, it is common to use a relatively thick mold core to form the mold, see the mold core 1 shown in FIG. 1 . The mold core is usually made of stainless steel after heat treatment, and then wheel-grinded and polished to a mirror surface. If a micro-shaped structure on the surface is required, it is processed again.

The mold core is occasionally damaged during molding or mold maintenance, so it is necessary to replace the new mold core, but the mold core with a large thickness has the following disadvantages: the cost of the mold core material required due to the large thickness is high, and it is easy to have equipment for processing. The limitation of the processing range, or the heavy weight and difficult placement during assembly and disassembly will cause additional damage.

The purpose of the present invention is to provide a method for manufacturing a micro-shaped plate optical element on the surface, which is formed by using a master mold sheet with an optical effect shape on the surface, and the shape can be formed into a concave shape by an etching method or reused in this concave shape. Make a convex master template by electroforming. The method of the present invention improves the disadvantages of the prior art that the mold core is heavy and difficult to process and assemble, and the material cost is high when replacing, and adopts a mother mold piece with a greatly reduced thickness, which makes processing and assembly easy and saves material cost.

In order to achieve the above object, the present invention provides a method for manufacturing a plate-shaped optical element. The method uses a metal substrate as a mold core of a molding die. The manufacturing steps of the metal substrate are as follows: first, prepare a metal substrate, and The surface is polished to the required surface roughness; then the metal substrate is etched, and the shape and pattern with optical effects are engraved on the metal substrate; finally, the etched metal substrate is used as the mold core, and the optical plastic is injected into the mold. The desired plate optical element can be obtained.

The surface of the metal substrate can be additionally coated to increase the surface hardness.

Preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. In the attached picture:

Fig. 1 is the schematic diagram of existing forming method;

2A and 2B are schematic diagrams of substrate shape forming;

Fig. 3 is the schematic diagram of manufacturing mold according to the present invention;

Fig. 4 is a perspective view of an injection-molded component by a manufacturing mold according to the present invention.

Explanation of reference numbers:

1 mold core 33 mold cavities

2 metal substrates 34 gates

21 hole 35 injection port

3 mold 4 light guide element

31 upper mold 41 protruding cylinder

32 lower mold 42 exit surface

This embodiment is for forming a light guide element of a backlight assembly. 2A and 2B are schematic diagrams of substrate shape forming.

As shown in FIG. 2A , a metal substrate 2 with a thickness of 0.2 mm to 5 mm is prepared as a master mold of a forming mold, and the metal substrate 2 is processed to a required surface roughness.

As shown in FIG. 2B , the metal substrate 2 is etched to form holes 21 , and the etching methods include: chemical etching, electrolytic etching, hybrid etching and other methods.

As shown in FIG. 3 , the etched metal substrate 2 is attached to a mold 3 . Fitting methods include edge clamping, bottom vacuum adsorption, pasting and other methods. The mold 3 includes: an upper mold 31 , a lower mold 32 , a mold cavity 33 , a gate 34 , and a material injection port 35 . During molding, the optical plastic material is injected into the injection port 35, passes through the gate 34 to the mold cavity 33, and leaves the mold 3 after cooling to obtain the required plate-shaped optical element. Forming methods for plate-shaped optical components include injection molding, casting, hot pressing, and transfer molding. The surface of the metal substrate 2 can be additionally coated to increase the surface hardness.

As shown in FIG. 4 , the surface of the molded light guide element 4 has a protruding cylinder 41 , which is transferred from the hole 21 of the metal substrate 2 during molding. The protruding cylinder 41 has the effect of reflecting light to the exit surface 42 .

Although the manufacturing method of the present invention has been described above in conjunction with preferred embodiments, it is only an illustration, and does not limit the scope of the present invention. As long as it does not depart from the gist of the present invention, those skilled in the art can carry out various deformations or change.

Claims (6)

1. A method for manufacturing a plate optical element, comprising the following steps: (1) Prepare a metal substrate with a thickness of 0.2mm to 5mm as the master mold of the molding die; (2) processing the surface of the metal substrate to the required surface roughness; (3) engraving holes on the metal substrate by etching; (4) Using the metal substrate as a master mold and fixing it in a mold, and then injecting optical plastic material into transfer molding to obtain the required plate-shaped optical element. 2. The method for manufacturing a plate-shaped optical element according to claim 1, wherein the material of the metal substrate is a series of stainless steel alloys. 3. The method for manufacturing a plate-shaped optical element according to claim 1, wherein the metal substrate is copied into a new master mold through at least one transfer. 4. The manufacturing method of a plate-shaped optical element according to claim 1, wherein the metal substrate is electroformed at least once to form a new master mold. 5. The method for manufacturing a plate-shaped optical element according to claim 1, wherein the surface of the metal substrate is further coated to increase surface hardness. 6. A plate-shaped optical element manufactured by the method of claim 1.

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