Process for producing glass optical element and method for determining glass component of glass blank

A technology for optical components and manufacturing methods, which are used in optical components, glass molding, glass pressing, etc.

Inactive Publication Date: 2003-09-10
HOYA CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0018] The method described in JP-A-7-330354 intends to eliminate the deviation between the predicted value of the index drop of the molded lens and the actual value, but does not provide any solution for the drop itself

Method used

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  • Process for producing glass optical element and method for determining glass component of glass blank
  • Process for producing glass optical element and method for determining glass component of glass blank

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0148] Next, the present invention will be described in more detail while finding the best embodiment.

[0149] In the following examples, the refractive index n is used d , Abbe number γ d as an optical constant.

reference example 1

[0151] Using barium borate optical glass (basic composition: SiO 2 37.8wt%, B 2 o 3 24.0wt%, Al 2 o 3 5.3wt%, Li 2 O8.5wt%, CaO5.0wt%, BaO16.1wt%, La 2 o 3 3.3wt%, As 2 o 3 0.5wt%, Sb 2 o 3 0.2 wt%, Tg: 500 degrees), to produce glass lenses.

[0152] The above-mentioned barium borate glass was melted, flowed down from an outflow pipe, cut and cooled (quenched in the atmosphere) to obtain a preform (glass blank for press molding) in the shape of an oblate sphere. The strain of this preform was large, and the refractive index could not be measured, but it was estimated to be a rather low value. Keep at Tg+30 degrees for 2 hours, cool to the strain point below -50 degrees at a cooling rate of 30 degrees / hour, and measure the refractive index (n) at room temperature d 1.58900, gamma d 61.30). These are referred to as the standard refractive index and the standard Abbe number.

[0153] The above-mentioned quenched preform is sent to a press-forming process to be pres...

Embodiment 1

[0157] Implement the refractive index n of the preform shown in reference example 1 under Tg+30 degrees for 2 hours, and cooling (processing under specified conditions) at a cooling rate of 30 degrees / hour d 1.58900 and the Abbe number¶ d 61.30 is the standard refractive index and standard Abbe number, which is determined by n 1 And γ1 said the refractive index and Abbe.

[0158] In addition, in Reference Example 1, by press-forming the glass of the above-mentioned composition under the above-mentioned conditions, it becomes n d 1.58600, Abbe number γ d 61.25. That is, n 2 for n d 1.58600, γ2 for γ d 61.25.

[0159] That is, n 1 -n 2 300×10 -5 , γ1-γ2 is 0.05.

[0160] And, as the expected value of the lens design (n 3 and γ3), select and n 1 and the same n as γ1 d 1.58900 and gamma d 61.30, try lens shaping.

[0161] Alternatively, the modulation standard refractive index ratio n 3 High 300×10 -5 The glass blank is used as a preform (glass blank), so that af...

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Abstract

Provided is a method for manufacturing glass optical elements having desired refractive index with a simple and convenient rule and a high precision even when glass blank material supplied for a press molding working procedure suffers a thermal hysteresis after being melted. Said method for manufacturing glass optical elements of desired refractive index n3 by means of a press molding process (namely the first manufacturing method mentioned below) comprises utilizing a shaping mould to press molding a softened glass material in a pressing mold and then cooling it. The method comprises preparing a interim optical element by means of the press molding process from a glass material of a prescriptive composition, measuring a refractive index n2 of the interim optical element, obtaining the difference between a standard refractive index n1 of the prescriptive composition processed with a prescriptive condition and the refractive index n2 of the interim optical element mentioned above, preparing a certain glass composition having standard refractive index substantially of the value which is obtained by adding the difference to the refractive index n3, and preparing an optical element by means of the press molding process from a glass material of the certain glass composition.

Description

technical field [0001] The present invention relates to a method for manufacturing a high-precision glass optical element. Specifically, the present invention relates to a method of forming a softened glass blank by pressing a molding mold with a specified surface accuracy, and transferring the molding surface of the molding mold to the above-mentioned glass blank. Above, a method of manufacturing a glass optical element with desired surface accuracy and optical characteristics. Background technique [0002] In recent years, precision press forming technology has been developed that does not require grinding and grinding steps after press forming, and a large number of lenses, especially aspheric lenses, have been produced by this technology. [0003] In the manufacture of glass optical components, the management of optical properties is indispensable. This is determined by the specification of the optical product to which the glass optical element is applied, and is usuall...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C03B11/08C03B11/12
CPCC03B11/08C03B11/125Y02P40/57
Inventor 广田慎一郎佐藤浩一
Owner HOYA CORP
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