Method for optically making a diffusion plate

• US 4,336,978 A
• Filed: 12/20/1979
• Issued: 06/29/1982
• Est. Priority Date: 12/26/1978
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Suzuki, Takashi
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): ARNOLD, BRUCE
• Application Number:
  US06/105,884
• Time in Patent Office: 922 Days
• Field of Search: 350/162 R, 350/167, 350/320, 350/431
• US Class Current: 359/599
• CPC Class Codes: G02B 3/00 Simple or compound lenses
• CPC Class Codes: G02B 5/0221 the surface having an irregular structure G02B5/0226 takes precedence
• CPC Class Codes: G02B 5/0268 characterized by the fabrication or manufacturing method
• CPC Class Codes: Y10S 359/90 Methods

Abstract

A method for optically making a diffusion plate is disclosed which comprises the steps of illuminating a particular object, recording the light coming from the object on a recording material without imaging said object to form a speckle pattern thereon, and subjecting the recording material to a treatment process. The particular object used in the method is one which has a regular phase and/or amplitude structure in macroscopic view but contains an irregular phase and/or amplitude structure in a view of wavelength level of the light illuminating the object.

Claims

1. A method for optically making a diffusion plate comprising the steps of:

illuminating an object having a regular macrostructure and an irregular microstructure with coherent light;

directing the light coming from said object without imaging said objects, onto a recording material to form a speckle pattern thereon; and

subjecting said recording material to a treatment so as to obtain a diffusion plate.

3. A method for optically making a diffusion plate according to claim 1 or 2 wherein said object is an object which contains a structure composed of a number of microprism elements closely arranged, each of said elements being imcomparably larger than the wavelength of said illumination light.

4. A method for optically making a diffusion plate according to claim 1 or 2 wherein said object is a fly eye lens.

5. A method for optically making a diffusion plate according to claim 1 or 2 wherein said object is a lenticular lens.

6. A method for optically making a diffusion plate according to claim 1 or 2 wherein said object is a diffraction grating.

2. A method for optically making a diffusion plate comprising the steps of:

illuminating an object having rotation asymmetric diffusion characteristics with coherent light;

recording the light coming from said object without imaging said object, onto a recording material to form a speckle pattern thereon; and

subjecting said recording material to a treatment so as to obtain a diffusion plate.