JPH0517173A - Production of cover glass for electronic equipment - Google Patents

Abstract

PURPOSE:To provide the title glass to be used for the transparent covers (apertures) for the displays or light-receiving devices of electronic equipment such as light-emitting diodes, photosensors, CCDs or optical filters. CONSTITUTION:The objective production characterized by comprising (A) a process designed to putting a glass block 21 into a mold 1 and molding it under heating to a specified shape in advance, (B) a second process designed to melt under heating the resultant form while pressing with a relevant mold to such an extent as to provide said form's side with arc convex surface 13, and (C) a third process designed to abrade the resulting raw material plate 12 to a specified thickness. With this method, there is no disadvantage of developing the objective cover glass distortion due to the residual stress developed during beveling process, good quality can also be obtained in terms of smoothness with entirely no developing striae liable to be produced in conventional methods, thus removing conventional drawbacks of developing distortions in received images or displayed characters when applied to electronic equipment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a cover glass for an electronic device, which includes a transparent cover (window) of a display device of an electronic device such as a light emitting diode, a photo sensor, a CCD, an optical filter, a light receiving device, and the like. Regarding

[0002]

2. Description of the Related Art Light emitting diodes, photo sensors, CCs
A display device of electronic equipment such as D and a transparent cover (window) of the light receiving device constitute predetermined electronic equipment. These electronic devices are fluorescent, liquid crystal, LED, etc.
It is designed to display images and images, and has a light-emitting plate (base glass) that emits and displays a required character by an electric signal enclosed therein.

Conventionally, in manufacturing the cover glass for electronic devices, a large-sized blank formed by a conventional method is cut into a required size as shown in FIG. 7, and then the surface is polished. To obtain a cover glass 41 for an electronic device, and a chamfered end face 42 was chamfered as shown in FIG.

[0004]

However, in the above-described conventional manufacturing method, it takes a lot of time and labor to chamfer a large number of end faces 42, which significantly lowers productivity and also causes an increase in cost. There was a flaw.

Further, there are drawbacks in that mist is generated at the time of attachment to a jig for chamfering or the like, which reduces the yield of products and adversely affects the working environment.

Further, the residual stress generated in the chamfering process causes a distortion of the cover glass for an electronic device to be obtained, which impairs the smoothness of the cover glass and causes a distortion of a received light image or a displayed character.

According to the conventional manufacturing method, when a large-sized material plate is cut into a required size as shown in FIG.
There are chippings and fine cracks on the cut end face,
Such chipping and cracks have a drawback that they are further increased rather than eliminated in the subsequent chamfering step. Then, the minute glass pieces caused by the chipping and cracks may adversely affect the incorporated electronic devices.

The method of manufacturing the cover glass for electronic equipment of the present invention is intended to solve the above-mentioned drawbacks of the conventional example, and adopts a completely different manufacturing method to improve the productivity, improve the product yield and reduce the cost. And a method for manufacturing a cover glass for an electronic device, which is capable of supplying a high-quality cover glass for an electronic device.

[0009]

That is, a method of manufacturing a cover glass for an electronic device according to the present invention comprises a step of housing a glass block in a frame and heat-molding the glass block into a predetermined shape in advance.
It is characterized by comprising a step of heating and melting a molded article formed in a predetermined shape while pressing it with a pressing die to the extent that the side surface has an arcuate convex surface, and a step of polishing the obtained material plate to a predetermined thickness. It is a thing.

As the glass material used in the present invention,
Low expansion glass such as borosilicate glass, heat resistant glass such as Pyroceram (trade name), and other glass materials used for electronic parts are suitable.

[0011]

Since the method of manufacturing the cover glass for electronic equipment of the present invention is configured as described above, the chamfering of the end face is not required, the productivity is dramatically improved, and a significant cost reduction can be achieved. ..

Further, mist is not generated by chamfering processing, the number of defective products is reduced, the product yield is improved, and a good working environment can be maintained at all times.

Further, there is no defect that the cover glass for electronic equipment is distorted by the residual stress generated in the chamfering process, good quality can be obtained in smoothness, and the striae tend to occur in the conventional manufacturing method. However, the defect of the conventional example that the received light image, the displayed characters, and the like are distorted when applied to electronic devices is solved.

It is possible to provide a high-quality cover glass for electronic equipment, which is free from the occurrence of chipping and cracks found in the conventional manufacturing method.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing a cover glass for electronic equipment according to the present invention will be described in detail below with reference to the drawings.

FIGS. 1 to 3 show an example of a molding die used in the present invention, which is composed of a mold 1 and a male mold 7. In the figure, reference numerals 2 and 3 denote a backing plate and an intermediate plate which form the mold 1, each of which is made of a carbon jig. Positioning posts 4 are erected at the four corners of the receiving plate 2 and are inserted into the positioning holes 5 provided at the four corners of the intermediate plate 3 for assembly. Reference numeral 6 denotes an opening of a predetermined shape provided in the middle plate 3, and the glass block 21 is housed in a space defined by the opening 6 and the upper surface of the receiving plate 2.

Reference numeral 7 is a male die, and this male die 7 is also composed of an upper plate 8 made of a carbon jig, and the opening 6 of the intermediate plate 3 is formed.
If the convex portion 9 of FIG. 3 that fits on the upper part of the glass block 21 is formed, the glass block 21 can be surely pressed. In the figure, 11 are positioning holes provided at the four corners of the upper plate 8.

2 and 3, the process of heat-molding the glass block 21 using the mold 1 and the male mold 7 will be described.

First, as shown in FIG. 2, the post 4 is fitted into the positioning hole 5, the middle plate 3 is fixed on the receiving plate 2, and the glass block 21 is put into the opening 6 of the middle plate 3. Then, the upper plate 8 is mounted on the intermediate plate 3 while fitting the positioning holes 11 into the posts 4. Then, as shown in FIG. 3, while the convex portion 9 of the upper plate 8 is fitted into the opening 6, pressure is applied from the upper plate 8 side, and heat molding is performed for a predetermined time at the melting temperature of the glass block 21.

The mold 1 and the male mold 7 set as described above are sent to a furnace having a slow heating slow cooling means by a carrying means such as a conveyor. The above-mentioned furnace is formed to have a certain length in order to enhance mass productivity, and when the glass block 21 carried into the furnace is sent out from the furnace end, it is in a state of being already molded and cooled and solidified. .. An electric heater is used as a heating source of this furnace, and is adjusted to have a temperature distribution convenient for melt-forming the glass block 21.

The glass block 21 fed into the furnace together with the mold 1 and the male mold 7 is melted and softened as it moves in the furnace while being heated by an electric heater. In this case, heating is gradually performed, so that the glass block 21 only softens while uniformly maintaining a predetermined shape as a whole, and thus the obtained material plate 12 maintains a predetermined quality and does not cause internal distortion. It naturally has a predetermined shape. In this heat molding step, the glass block 21 is molded into a predetermined shape, and when it is gradually cooled and exits from the furnace, it is contracted and released from the mold 1 and the male mold 7, and the material plate 12 after molding is easily You can take it out.

The material plate 12 whose side surfaces are acute angles and R is not yet formed is pressed from both sides by a carbon pressing die 10 having flat surfaces and heated to a predetermined temperature. Due to the surface tension of the melted and softened material plate 12, an arcuate convex surface 13 is formed on the side surface. Above pressurization
The heating step may be performed in the same furnace as above, or the pressurizing / heating step may be separately performed by a batch system.

FIG. 5 and FIG. 6 show a cover glass 31 for electronic equipment obtained by heating and melting, the side surface of which has an arcuate convex surface 13. In order to obtain by heating and melting the cover glass 31 for an electronic device whose side surface is the arcuate convex surface 13, the melting temperature and the degree of pressurization of the die 10 are adjusted and the surface tension of the glass in the molten state is adjusted. It is necessary to adjust so that the side surface becomes an arcuate convex surface.

The cover glass 31 for electronic devices thus obtained is ground to a predetermined thickness,
Even if this polishing is performed, the obtained electronic device cover glass has not yet formed an acute angle between the front and back surfaces and the side surfaces, and the surface is kept smooth without residual stress due to chamfering, Ready to ship as is.

In the above, the mold 1 and the male mold 7 are used.
Can be made into an arbitrary shape such as a circle, an ellipse, or a polygon as well as a rectangle, so that a cover glass for an electronic device having an appropriate shape can be easily manufactured. This has a remarkable effect in other aspects such as the degree of freedom of shape, ease of processing, etc., as compared with the conventional provision of a material plate by cutting.

[0026]

Since the method of manufacturing the cover glass for electronic equipment of the present invention is constructed as described above, the chamfering of the end face is not necessary, the productivity is dramatically improved, and a significant cost reduction is achieved. You can

Further, mist is not generated by chamfering processing, the number of defective products is reduced, the product yield is improved, and a good working environment can be maintained at all times.

Further, there is no defect that the cover glass for electronic equipment is distorted by the residual stress generated in the chamfering process, good quality can be obtained in smoothness, and the striae tend to occur in the conventional manufacturing method. However, the defect of the conventional example that the received light image, the displayed characters, and the like are distorted when applied to electronic devices is solved.

The side surface of the cover glass for electronic devices obtained by the present invention is arcuate, but very smooth, does not generate mist during various subsequent processing, and has a good light transmittance. You can get good and very high quality electronic cover glass.

[Brief description of drawings]

FIG. 1 is a perspective view of a mold and a male mold used in the method for manufacturing a cover glass for an electronic device according to the present invention.

FIG. 2 is a cross-sectional view of a glass block at the time of loading during a manufacturing process.

FIG. 3 is an enlarged cross-sectional view of the glass block when pressure is applied.

FIG. 4 is a cross-sectional view of the glass block when pressure is applied.

FIG. 5 is a perspective view showing a cover glass for electronic equipment obtained by heating and melting.

FIG. 6 is an enlarged cross-sectional view of a cover glass for electronic device.

FIG. 7 is a perspective view of a conventional cover glass for electronic equipment.

FIG. 8 is an enlarged cross-sectional view of a conventional cover glass for electronic equipment.

[Explanation of symbols]

 1 Formwork 2 Support Plate 3 Middle Plate 4 Positioning Post 5 Positioning Hole 6 Opening 7 Male 8 Top Plate 9 Convex 10 Stamping 11 Positioning Hole 12 Material Plate 13 Circular Convex 21 Glass Block 31 For Electronic Equipment cover glass

Claims (1)

Claim: What is claimed is: 1. A step of accommodating a glass block in a shape frame and heat-molding the glass block into a predetermined shape in advance; A method for producing a cover glass for electronic equipment, comprising: a step of heating and melting while pressing with a pressing die; and a step of polishing the obtained material plate to a predetermined thickness.