Reflection holograms without transmission ghosts

• US 5,196,951 A
• Filed: 06/26/1991
• Issued: 03/23/1993
• Est. Priority Date: 06/26/1991
• Status: Expired due to Term

• Current Assignee: Dai Nippon Printing Company Limited
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Wreede, John E.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/721,726
• Time in Patent Office: 636 Days
• Field of Search: 359/1, 359/22, 359/25, 359/30, 359/568, 359/15
• US Class Current: 359/15
• CPC Class Codes: G02B 2027/0105 Holograms with particular structures
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 27/0103 comprising holographic elements
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G03H 1/0256 having specific functional layer

Abstract

A reflection hologram structure including a transparent substrate, and a pattern of shielded hologram containing regions and transparent regions disposed on the transparent substrate, the pattern being unresolvable to the viewer. The shielded hologram containing areas comprise hologram subregions and shielding subregions overlying the hologram subregions. The shielding subregions comprise for example, opaque regions or partially illumination transmissive regions.

Claims

1. A reflection hologram structure comprising:

a transparent substrate;

a pattern of hologram containing regions disposed on the transparent substrate; and

fixed predetermined shielding regions disposed over said hologram containing regions for said reflection hologram structure.

2. The reflection hologram structure of claim 1 wherein said shielding regions comprise opaque regions disposed on said hologram containing regions and in registration therewith.

3. The reflection hologram structure of claim 1 wherein said shielding regions comprise partially light transmission regions disposed on said hologram containing regions and in registration therewith.

4. The reflection hologram structure of claim 1 wherein said shielding regions comprise opaque regions of greater lateral extent than said hologram containing regions.

5. The reflection hologram structure of claim 1 wherein said shielding regions comprise partially light transmission regions of greater lateral extent than said hologram containing regions.

6. A method for making a reflection hologram structure comprising the steps of:

exposing and developing a hologram recording layer;

applying an illumination shielding layer over the developed hologram layer; and

removing selected areas of the illumination shielding layer and the hologram recording layer.

7. The method of claim 6 wherein the illumination shielding layer comprises an opaque layer.

8. The method of claim 6 wherein the illumination shielding layer comprises a partially light transmissive layer.

9. A method for making a reflection hologram structure comprising the steps of:

exposing and developing a hologram recording layer;

removing selected areas of the hologram recording layer to provide hologram containing regions and open areas;

applying an illumination shielding layer over the hologram containing regions and the open areas; and

removing selected areas of the illumination shielding layer such that the hologram containing regions are covered by illumination shielding regions.

10. The method of claim 9 wherein the illumination shielding layer comprises an opaque layer.

11. The method of claim 9 wherein the illumination shielding layer comprises a partially light transmissive layer.