Patent · US Expired

Developing method and developing apparatus for optical record medium

US5759749A · kind A · utility

2Cited by
4References
5Claims
0Family size

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Key dates

Filing dateMar 21, 1997
Grant dateJun 2, 1998
Priority date
Expiry dateMar 21, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B7/261
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A photo-resist layer of positive type, which is formed by a predetermined thickness on a disc substrate and which is exposed by a light beam modulated in accordance with record information to produce an optical record medium comprising the photo-resist layer and the disc substrate, is developed by the developing method. The developing method includes the steps of: firstly developing the exposed photo-resist layer by alkaline developing solution which has a normality of 0.17 to 0.19N for a first time period such that the photo-resist layer be incompletely developed to a predetermined depth from a surface of the exposed photo-resist layer; firstly washing the firstly developed photo-resist layer to stop the firstly developing step, and firstly drying the firstly washed photo-resist layer; secondly developing the firstly dried photo-resist layer by the alkaline developing solution for a second time period which is longer than the first time period such that the photo-resist layer be completely developed to a pit depth; and secondly washing the secondly developed photo-resist layer to stop the secondly developing step, and drying the secondly washed photo-resist layer to produce the op…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.