Method of manufacturing a disc-shaped information carrier

• US 5,242,630 A
• Filed: 02/18/1992
• Issued: 09/07/1993
• Est. Priority Date: 02/28/1991
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Van den Bekerom, Peter P. W. L., Mulder, Evert-Jan, Nuij, Pieter W. J. M.
• Primary Examiner(s): Thurlow, Jeffery
• Assistant Examiner(s): VARGOT, MATHIEU D
• Application Number:
  US07/839,016
• Time in Patent Office: 567 Days
• Field of Search: 264/1.1, 264/1.3, 264/106, 264/107, 264/325, 264/320, 264/22, 264/293, 425/810, 425/111, 425/174.4, 369/275.1, 369/284
• US Class Current: 264/1.33
• CPC Class Codes: B29C 59/02 by mechanical means, e.g. pressing B29C59/007 takes precedence; embossing expanded porous articles B29C44/5627
• CPC Class Codes: B29D 17/005 Producing optically read record carriers, e.g. optical discs
• CPC Class Codes: G11B 7/263 Preparing and using a stamper, e.g. pressing or injection molding substrates production of optical record carriers, e.g. optical discs B29D17/005
• CPC Class Codes: Y10S 425/81 Sound record

Abstract

A method of manufacturing an object having a surface structure, the method employing pressure members (3, 5) which are movable relative to one another and which have facing pressure surfaces (23, 25). A first element (51) and a second element (53) having a relief on one surface are pressed against one another to provide the second element with a microstructure by cold deformation. During pressing use is made of a pressure body (27, 29) which is interposed between one of the pressure members and one of the elements and which is made of a material having a characteristic parameter equal to the quotient of the Poisson'"'"'s ratio and the modulus of elasticity of the material, which parameter differs less from the corresponding parameter of the material of the relevant element than from the corresponding parameter of the material of the relevant pressure member. The difference between the parameter of the material of the first element and the parameter of the material of the second element being smaller than or equal to the difference between the parameter of the material of said pressure body and the parameter of the material of the adjacent element.

Claims

1. In a method of manufacturing an object having a surface structure, said method employing first and second pressure members which are movable relative to one another and which have facing pressure surfaces by which a first element and a second element, which first element has a relief on a surface, are pressed against one another to provide the second element with a microstructure by cold deformation, the improvement wherein during pressing a pressure body is interposed between one of the pressure members and one of the elements and which pressure body is made of a material having a characteristic parameter equal to the quotient of the Poisson'"'"'s ratio and the modulus of elasticity of the material, which parameter differs less from the corresponding parameter of the material of said one of the elements than from the corresponding parameter of the material of its pressure member, the difference between the parameter of the material of the first element and the parameter of the material of the second element being smaller than or equal to the difference between the parameter of the material of said pressure body and the parameter of the material of the other of said elements.

2. A method as claimed in claim 1, wherein, in addition, a pressure body is interposed between the other pressure member and the other element.

3. A method as claimed in claim 1, wherein the material of the pressure body is selected in such a way that the characteristic parameter is at least substantially equal to the characteristic parameter of the material of the other element.

4. A method as claimed in claim 1, wherein both elements are made at least substantially from plastic, and the pressure body is made of plastic.

5. A method as claimed in claim 1, in which the object is a disc-shaped information carrier and both elements comprise a polycarbonate substrate, and that the pressure body is made of a polycarbonate.