Method for producing transparent type hologram

• US 6,020,090 A
• Filed: 09/04/1997
• Issued: 02/01/2000
• Est. Priority Date: 09/05/1996
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation, Nippon Soken, Inc.
• Original Assignee: DENSO Corporation, Nippon Soken, Inc.
• Inventors: Shiozawa, Masahiro, Kurokawa, Kazumasa, Kanda, Tomoyuki, Nishii, Katsuyoshi, Takada, Kenichiro, Koike, Satoshi
• Primary Examiner(s): ANGEBRANNDT, MARTIN J
• Application Number:
  US08/923,667
• Time in Patent Office: 880 Days
• Field of Search: 430/1, 430/2, 359/1, 359/3, 359/11, 359/30, 359/31, 359/13, 359/35
• US Class Current: 430/1
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G03H 1/04 Processes or apparatus for producing holograms G03H1/26 takes precedence
• CPC Class Codes: G03H 1/0465 Particular recording light; Beam shape or geometry G03H1/06 takes precedence
• CPC Class Codes: G03H 2001/0413 for recording transmission holograms
• CPC Class Codes: G03H 2001/043 Non planar recording surface, e.g. curved surface
• CPC Class Codes: G03H 2001/2615 in physical contact, i.e. layered holograms
• CPC Class Codes: G03H 2210/562 Holographic object, i.e. a combination of an object and holobject G03H1/20 takes precedence
• CPC Class Codes: G03H 2223/14 Diffuser, e.g. lens array, random phase mask
• CPC Class Codes: G03H 2223/18 Prism

Abstract

Method for producing a of a transparent type hologram screen of an wide visible range. A photosensitive member and a light source of a reference light are arranged on the same side of the light diffusing body. A light source of an object light is arranged on the opposite side of the light diffusing body, so that the light is transmitted through the light diffusing body to generate a object light. A light from a light source of a reference light is reflected at the light diffusing body or a member such as a half mirror or a transparent, reflective hologram element arranged at a front side of the light diffusing body.

Claims

1. A method for producing a transparent holographic diffusion screen, said method comprising:

spacing a photosensitive member away from a light diffusing body;

positioning a half mirror between said light diffusing body and said photosensitive member, a reflecting surface of said half mirror facing said photosensitive member;

passing a first light through said light diffusing body and said half mirror to obtain diffuse light used as an object light;

reflecting a second light off said half mirror to obtain a reference light incident to said photosensitive member; and

exposing said photosensitive member to said object light and said reference light on the same side of said photosensitive member to produce a hologram on which said light diffusing body is recorded.

2. A method for producing a transparent holographic diffusion screen, said method comprising:

spacing a photosensitive member away from a light diffusing body;

positioning a Lippmann type hologram element between said light diffusing body and said photosensitive member, said Lippman type hologram element capable of reflecting a reference light, regularly or irregularly;

passing a light through said light diffusing body and said Lippmann type hologram element to obtain diffuse light used as an object light;

reflecting a second light, regularly or irregularly, on said Lippman type hologram element to obtain a light incident to said photosensitive member, said incident light used as a reference light; and

exposing said photosensitive member to said object light and said reference light on the same side of said photosensitive member to produce a hologram on which said light diffusing body is recorded.

3. A method for producing a transparent holographic diffusion screen, said method comprising:

positioning a transparent light diffusing body, in a light path to a photosensitive member, said transparent light diffusion body having directivity such that only light in a predetermined range of an incident angle is subject to diffusion;

passing a light in said incident angle range through said light diffusing body to obtain a diffuse light used as an object light;

passing a second light outside said incident angle range through said light diffusing body to obtain non-diffuse light used as a reference light; and

exposing said photosensitive member to said object light and said reference light on the same side of said photosensitive member to produce a hologram on which said light diffusing body is recorded.

4. A method for producing a transparent holographic diffusion screen, said method comprising:

positioning a Fresnel type hologram element on which a light diffusing body is recorded in a light path to a photosensitive member, said Fresnel type hologram element having a curved shape;

positioning said photosensitive member at a center of a curvature of said curved shape;

diffracting a light at said Fresnel type hologram element to obtain diffuse light used as an object light;

passing a second light through said Fresnel type hologram element to obtain non-diffuse light used as a reference light; and

exposing said photosensitive member to said object light and said reference light on the same side of said photosensitive to produce a hologram on which said light diffusing body is recorded.

5. A method for producing a transparent holographic diffusion screen, said method comprising:

positioning a Lippmann type hologram element on which a light diffusion body is recorded, in a light path to a photosensitive member, said Lippmann type hologram element having a curved shape;

positioning said photosensitive member at a center of a curvature of said curved shape;

diffracting and reflecting a light by said Lippmann type hologram element to obtain diffuse light used as an object light, said light being divergent light from an opposite side of said photosensitive member;

passing a second light through said Lippmann type hologram element to obtain non-diffuse light used as a reference light; and

exposing said photosensitive member to said object light and said reference light on the same side of said photosensitive member to produce a hologram on which said light diffusing body is recorded.

6. A method for producing a transparent holographic diffusion screen, said method comprising:

positioning a first transparent hologram element and a second transparent hologram element in a light path to a photosensitive member, said second hologram element being closer to said photosensitive element than said first hologram element;

said first hologram element being a Lippmann type hologram element on which a light diffusion body is recorded;

said second hologram element being a Lippmann type hologram on which a plane mirror is recorded;

passing a light through said first and second holograms elements to obtain a non-diffuse light used as a reference light;

passing a second light through said first hologram element, reflecting said second light partly at said second hologram element onto said first hologram element, reflecting said second light again at said first hologram element to obtain diffuse light used as an object light to reproduce said recorded light diffusing body, and passing said second light through said second hologram element onto said photosensitive member; and

exposing said photosensitive member to said object light and said reference light on the same side of said photosensitive member to produce a hologram on which said light diffusing body is recorded.

7. A method for producing a transparent holographic diffusion screen, said method comprising:

spacing a photosensitive member away from a light diffusing body;

providing a reflective optical element located at an end of said light diffusing body adjacent to a light path for a reference light, said reflective optical element extends parallel to or at an angle to said light diffusing body from said end toward said photosensitive member;

said reflective optical element having a function that a part of said diffuse light passes through said light diffusing body is partly reflected at said reflective optical element;

passing a light through said light diffusing body and onto said photosensitive member and reflecting a light at said reflective optical element and onto said photosensitive member to obtain a diffuse light used as an object light;

diverging a light used as a reference light; and

exposing said photosensitive member to said object light and said reference light on one side to produce a hologram on which said light diffusing body is recorded.

8. A method as claimed in claim 7, wherein said reflective optical element comprises a transparent element through which said diverging light partly passes, said reflective optical element positioned across a light path of said reference light to said photosensitive member.

9. A method for producing a transparent holographic diffusion screen, said method comprising:

spacing a photosensitive member away from a light diffusing body;

providing a convex lens at a front surface of said photosensitive member, thereby increasing an incident angle to said photosensitive member;

passing a light through said light diffusing body to obtain a diffuse light used as an object light;

diverging a second light used as a reference light directly to said photosensitive member without passing through said light diffusing body; and

exposing said photosensitive member to said object light and said reference light on the same side of said photosensitive member to produce a hologram on which said light diffusing body is recorded.

10. A method for producing a transparent holographic diffusion screen, said method comprising:

spacing a photosensitive member away from a light diffusing body;

providing a Fresnel type hologram element in front of said photosensitive member, said Fresnel type hologram element having a function of diffracting divergent light toward said photosensitive member at an angle of a diffracted light with respect to the normal line of an outlet surface of said diffracted light which is less than an angle of an incident light with respect to the normal line of an inlet surface;

diffracting a divergent light used as a reference light by said Fresnel type hologram element;

passing a second light through said light diffusing body and said Fresnel type hologram element to obtain diffuse light used as an object light; and

exposing said photosensitive member to said object light and said reference light on the same side of said photosensitive member to produce a hologram on which said light diffusing body is recorded.

11. A method for producing a transparent holographic diffusion screen, said method comprising:

spacing a photosensitive member away from a light diffusing body;

providing a Fresnel type hologram element located on an inner portion of said light diffusing body, closer in than an end of said light diffusing body adjacent to a light path for a reference light, said Fresnel type hologram element projecting vertically or at an angle from said light diffusing body to said photosensitive member;

positioning said Fresnel type hologram element across said light path for said reference light, said Fresnel type hologram element having a function of diffracting divergent light toward said photosensitive member, and said

diffracted light projected at said photosensitive member at an angle similar to a reproduction light of a hologram screen;

diffracting a light used as a reference light by said Fresnel type hologram element;

passing a second light through said light diffusing body and onto said photosensitive member to obtain diffuse light used as an object light; and

exposing said photosensitive member to said object light and said reference light on the same side of said photosensitive member to produce a hologram on which said light diffusing body is recorded.

12. A method for producing a transparent holographic diffusion screen, said method comprising:

spacing a photosensitive member away from a light diffusing body;

providing a transparent Fresnel type hologram element at a front surface of said photosensitive member so that a divergent light may be introduced to said photosensitive member without passing through said light diffusing body;

recording a second light diffusing body, which is reproduced in a light path for said divergent light by said divergent light on said transparent Fresnel type hologram element, and which is not arranged in the structure of a system for exposure, said second light diffusing body having directivity that allows an incident light in a direction to be diffused, while said incident light from a different direction is not diffused, but passes directly through;

passing a first light through said light diffusing body and said transparent Fresnel type hologram element to obtain a diffuse light used as a first light;

passing a second light through said light diffusing body and diffracting said second light partly at said transparent Fresnel type hologram element to obtain said diffused light used as a second object light;

passing a third light through said transparent Fresnel type hologram element to obtain said divergent light used as a reference light; and

exposing said photosensitive member to said object light and said reference light on the same side of photosensitive member to produce a hologram on which said light diffusing body is recorded.

13. A method for producing a transparent holographic diffusion screen, said method comprising:

spacing a photosensitive member away from light diffusing body;

providing a prism between said photosensitive member and light diffusing body in a light path of a reference light and an object light, said prism having boundaries of desired respective characteristics for reflection or transparency such that a diffuse light passed through said light diffusing body is incident upon said photosensitive member as said object light after a direction of said diffuse light passing through said prism is changed at a corresponding boundary in said prism, while a divergent light reflects off the surface of said prism without passing through said light diffusing body and is incident upon said photosensitive member as a reference light; and

exposing said photosensitive member to said object light and said reference light on one side to produce a hologram on which said light diffusing body is recorded.