Method and apparatus for preparation of molded glass

• US 6,813,906 B1
• Filed: 10/31/2000
• Issued: 11/09/2004
• Est. Priority Date: 11/01/1999
• Status: Active Grant

• Current Assignee: Hoya Corporation
• Original Assignee: Hoya Corporation
• Inventors: Sugawara, Kishio, Hirota, Shinichiro
• Primary Examiner(s): Colaianni, Michael
• Application Number:
  US09/699,362
• Time in Patent Office: 1,470 Days
• Field of Search: 653/05, 653/07, 653/15, 653/17, 653/22, 653/23, 425/352
• US Class Current: 65/323
• CPC Class Codes: C03B 11/08 for making solid articles, e.g. lenses
• CPC Class Codes: C03B 11/122 Heating
• CPC Class Codes: C03B 2215/48 Convex-concave
• CPC Class Codes: C03B 2215/60 Aligning press die axes
• CPC Class Codes: C03B 2215/68 Means for parting the die from the pressed glass other than by cooling or use of a take-out
• CPC Class Codes: C03B 2215/73 with means to allow glass overflow in a direction perpendicular to the press axis
• CPC Class Codes: Y02P 40/57 Improving the yield, e-g- reduction of reject rates

Abstract

A molded glass article manufacturing device, having a means of forcefully separating a molded glass article attached to the forming surface of an upper mold or a lower mold, and readily and reliably aligning the axes of the upper mold and lower mold, a molded glass article manufacturing method, and a method of assembling a molded glass article manufacturing device are provided. A molded glass article manufacturing device comprising a drum capable of regulating an upper mold and a lower mold having opposing forming surfaces so that the displacement axes thereof align; a forced mold separating means separating a molded glass article adhered to a forming surface from the mold by contact with at least the rim portion of the molded glass object; and a displacement means for displacing said forced mold separating means relative to said upper mold or said lower mold so that, in the course of separation of said upper mold and said lower mold, said forced mold separating means contacts at least the rim portion of said molded glass article and separates said molded glass article from the forming surface. Further, a manufacturing method for molded glass articles employing this device and a method of assembling molded glass article manufacturing devices are disclosed.

Claims

1. An apparatus for manufacturing an optical element comprising:

an upper mold and a lower mold capable of being separated and approaching each other, each of the upper mold and the lower mold comprising a forming surface,

a regulator for regulating the upper mold and the lower mold to align the axes thereof wherein the regulator regulates the upper mold and the lower mold by direct contact with the upper mold and the lower mold,

a forcible releasing means for releasing the optical element adhered to a forming surface by contacting at least a rim portion of the optical element, and

a moving means for moving the forcible releasing means relative to the upper mold or the lower mold such that, in the course of the separation of the upper mold and the lower mold, the forcible releasing means contacts at least a rim portion of the optical element to release the optical element from the forming surface.

2. The apparatus of claim 1, wherein the moving means moves the forcible releasing means in conjunction with movement of the upper mold or lower mold in the course of separation of the upper mold and the lower mold.

3. The apparatus of claim 1, wherein the regulator comprises a drum.

4. The apparatus of claim 3, wherein the regulator guides vertical movement of the forcible releasing means.

5. The apparatus of claim 1, wherein the forcible releasing means is capable of releasing the optical element adhered to a forming surface of the upper mold.

6. The apparatus of claim 5, wherein the moving means is placed in an outer periphery of the upper mold.

7. The apparatus of claim 6, wherein the forcible releasing means is positioned away from the forming surface of the upper mold such that the forcible releasing means is in non-contact with the optical element, when the upper and the lower mold are approached.

8. The apparatus of claim 7, wherein the moving means comprises a spring.

9. The apparatus of claim 8, wherein the regulator comprises a drum.

10. The apparatus of claim 9, wherein the regulator guides vertical movement of the forcible releasing means.

11. The apparatus of claim 10, wherein the regulator guides movement of at least one of the upper mold or the lower mold by a clearance of 2 to 10 μ

m.

12. A method of manufacturing an optical element by press molding a glass material with an upper mold and a lower mold, wherein each of the upper mold and the lower mold comprises an upper forming surface and a lower forming surface, respectively, comprising:

press molding a heated glass material with the upper mold and the lower mold such that an outer diameter of said optical element becomes larger than an outer diameter of the upper forming surface,

cooling the optical element, and

separating the upper mold and the lower mold from each other,

wherein the axes of the upper mold and the lower mold are regulated by a regulator in the press molding step wherein the regulator regulates the upper mold and the lower mold by direct contact with the upper mold and the lower mold, and

in the separating step, a forcible releasing means is moved relative to the upper mold such that the forcible releasing means contacts a rim of the optical element adhered to the upper forming surface and releases the optical element from the upper forming surface.

13. The method of claim 12, wherein the regulator comprises a drum.

14. The method of claim 13, wherein the upper mold moves downward to follow shrinkage of the optical element in the cooling step.

15. The method of claim 14, wherein the upper mold, the lower mold and the glass material are heated to temperatures in a range corresponding to the viscosity of the glass material of 10⁸ to 10¹² poises, prior to the press molding step, and the separating step is carried out when the optical element is cooled to a temperature not higher than the transition temperature of the glass material.

16. The method of claim 15, wherein the heated glass material is transferred to the forming surface of the heated lower mold, prior to the press molding step.

17. The method of claim 16, wherein the heated glass material is floated by a gas and is transferred to the heated forming surface of the lower mold.