Method and apparatus for fabricating a light management substrates

• US 7,452,490 B2
• Filed: 04/29/2005
• Issued: 11/18/2008
• Est. Priority Date: 12/18/2002
• Status: Expired due to Fees

• Current Assignee: Sabic Innovative Plastics IP BV (Government of Saudi Arabia)
• Original Assignee: Sabic Innovative Plastics IP BV (Government of Saudi Arabia)
• Inventors: Olczak, Eugene, Liang, Erwin W.
• Primary Examiner(s): Vargot; Mathieu D.
• Application Number:
  US10/908,160
• Publication Number:
  US 20050199501A1
• Time in Patent Office: 1,299 Days
• Field of Search: 264/1.1, 264/2.5, 264/1.36, 264/1.38, 264/219, 425/808, 700/190, 700/191, 205/79
• US Class Current: 264/2.5
• CPC Class Codes: G05B 19/182 characterised by the machine tool function, e.g. thread cutting, cam making, tool direction control G05B19/21 - G05B19/40 take precedence
• CPC Class Codes: G05B 2219/35261 Use of mathematical expression, functional equation

Abstract

A method of machining a surface of a workpiece is accomplished by bringing a cutting tool into contact with the surface of the workpiece and for at least one cutting pass, i, causing relative movement between the cutting tool and the surface of the workpiece along a path in the surface of the workpiece. The path is in the nature of a mathematical function defined over a segment, C, of a coordinate system and characterized by a set of nonrandom, random or pseudorandom parameters selected from the group consisting of amplitude, phase and period or frequency. Relative movement between the cutting tool and the surface of the workpiece may be accomplished by bandpass filtering a noise signal; providing the bandpass filtered signal to a function generator; generating a randomly modulated mathematical function from the function generator; and in response to the randomly modulated function, directing the relative movement between the cutting tool and the surface of the workpiece along the path in the surface of the workpiece.

Claims

1. A method of fabricating an optical substrate from a machined master surface of a workpiece, the method comprising:

forming a replica of the master surface; and

transferring the replica of the master surface to an optical substrate;

wherein the master surface is formed by;

bringing a cutting tool into contact with an initial surface of the workpiece;

for a cutting pass, i, causing relative movement between the cutting tool and the initial surface along a path;

wherein the path is determined by processing a mathematical function defined over a segment, C, of a coordinate system and characterized by a parameter selected from the group consisting of amplitude, phase, and frequency;

wherein causing relative movement between the cutting tool and the initial surface comprises;

bandpass filtering a noise signal;

providing the bandpass filtered noise signal to a function generator; and

generating a randomly modulated mathematical function from the function generator;

cutting the initial surface by moving the cutting tool along the path according to the randomly modulated mathematical function.

2. The method of claim 1, wherein the forming the replica of the master surface comprises forming an electroform over the master surface.

3. The method of claim 1, wherein the forming the replica of the master surface comprises disposing an ultraviolet (UV) curing epoxy material on the master surface.

4. The method of claim 1, wherein the forming the replica of the master surface comprises disposing a thermal curing epoxy material on the master surface.

5. The method of claim 1, wherein the forming the replica of the master surface comprises disposing a silicon material on the master surface.

6. A method of fabricating an optical substrate from a machined master surface of a workpiece, the method comprising:

forming a replica of the master surface; and

transferring the replica of the master surface to an optical substrate;

wherein the master surface is formed by;

bringing a cuffing tool into contact with an initial surface of the workpiece;

for a cuffing pass, i, causing relative movement between the cutting tool and the initial surface along a path;

wherein the path is determined by processing a mathematical function defined over a segment, C, of a coordinate system and characterized by a parameter selected from the group consisting of amplitude, phase, and frequency;

and wherein the mathematical function is defined by the equation;

y_i=A_isin{Ψ

_i}+S_i

wherein i is an integer indicative of the number of the path, y_i is an instantaneous displacement of the cutting tool relative to C on the i^th cutting pass, A_i is a maximum displacement of the cutting tool relative to C, Ψ

_i is a phase of y_i, and S_iis a shift in the starting position of y_i;

and wherein

8. The method of claim 6, wherein N is a positive integer.

7. A method of fabricating an optical substrate from a machined master surface of a workpiece, the method comprising:

forming a replica of the master surface; and

transferring the replica of the master surface to an optical substrate;

wherein the master surface is formed by;

bringing a cuffing tool into contact with an initial surface of the workpiece;

for a cuffing pass, i, causing relative movement between the cutting tool and the initial surface along a path;

wherein the path is determined by processing a mathematical function defined over a segment, C, of a coordinate system and characterized by a parameter selected from the group consisting of amplitude, phase, and frequency;

and wherein the mathematical function is defined by the equation;

y_i=A_isin{Ψ

_i}+S_i

wherein i is an integer indicative of the number of the path, y_i is an instantaneous displacement of the cutting tool relative to C on the i^th cuffing pass, A_i is a maximum displacement of the cutting tool relative to C, Ψ

_i is a phase of y_i, and S_i is a shift in the starting position of y_i;

and wherein

9. The method of claim 7, wherein N is a positive integer.