Heads-up and heads-down displays employing holographic stereograms

• US 5,574,579 A
• Filed: 06/07/1995
• Issued: 11/12/1996
• Est. Priority Date: 02/14/1994
• Status: Expired due to Term

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Inventors: Molteni, William J., Volchok, William J.
• Primary Examiner(s): Dzierzynski, Paul M.
• Assistant Examiner(s): Schuberg, Darren E.
• Application Number:
  US08/478,513
• Time in Patent Office: 524 Days
• Field of Search: 359/9, 359/21, 359/22, 359/23, 359/25, 359/26, 359/32
• US Class Current: 359/23
• CPC Class Codes: G02B 2027/0109 comprising details concerning the making of holograms
• CPC Class Codes: G02B 2027/0112 comprising device for genereting colour display
• CPC Class Codes: G02B 2027/0129 comprising devices for correcting parallax
• CPC Class Codes: G02B 2027/0134 of stereoscopic type
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 2027/0145 creating an intermediate image
• CPC Class Codes: G02B 27/0103 comprising holographic elements
• CPC Class Codes: G03H 1/265 Angle multiplexing; Multichannel holograms G03H1/268 takes precedence
• CPC Class Codes: G03H 1/268 Holographic stereogram
• CPC Class Codes: G03H 2001/0413 for recording transmission holograms
• CPC Class Codes: G03H 2001/0415 for recording reflection holograms
• CPC Class Codes: G03H 2001/043 Non planar recording surface, e.g. curved surface
• CPC Class Codes: G03H 2001/2223 Particular relationship between light source, hologram and observer
• CPC Class Codes: G03H 2001/2231 Reflection reconstruction
• CPC Class Codes: G03H 2001/2234 Transmission reconstruction
• CPC Class Codes: G03H 2001/2236 Details of the viewing window
• CPC Class Codes: G03H 2001/2257 Straddling the hologram
• CPC Class Codes: G03H 2001/226 Virtual or real
• CPC Class Codes: G03H 2001/269 Two and more than two steps recording process
• CPC Class Codes: G03H 2210/42 from real object, e.g. using 3D scanner
• CPC Class Codes: G03H 2210/441 : Numerical processing applied to the object data other than numerical propagation
• CPC Class Codes: G03H 2210/454 : into planes
• CPC Class Codes: G03H 2222/22 : Spatial coherence
• CPC Class Codes: G03H 2222/42 : Reference beam at recording stage
• CPC Class Codes: G03H 2222/54 : Convergent beam
• CPC Class Codes: G03H 2270/21 : Curved bearing surface

Abstract

055745798

Heads-up and heads-down displays employing holographic stereograms are provided. The stereograms can be oriented perpendicular to the user'"'"'s line of sight (the "90° case") or at angle to the line of sight (the "non-90° case"). The stereograms are produced using a three-step process in which a series of two-dimensional perspective views are prepared, a H₁ hologram is prepared from the two-dimensional perspective views, and a H₂ hologram is prepared from the H₁ hologram. For the non-90° case, the two-dimensional perspective views are oriented at an angle relative to the plane of the H₁ hologram during the preparation of that hologram. Similarly, during the preparation of the H₂ hologram for this case, the H₂ hologram is oriented at an angle relative to the H₁ hologram. In this way, the viewing slits generated by the holographic stereogram are located in the vicinity of the user'"'"'s eyes for the non-90° case as is desired. In certain embodiments, the two-dimensional perspective views are transformed prior to being recorded on the H₁ hologram.

Claims

1. A holographic stereogram which produces an image which is perceived by a user along a line of sight, said holographic stereogram comprising a recording medium which defines a plane disposed non-orthogonally to the line of sight and which contains a diffraction pattern which upon illumination produces a set of two-dimensional perspective views and a set of viewing slits, one viewing slit for each of the two-dimensional perspective views, said viewing slits being located in the vicinity of the user'"'"'s eyes such that an image formed by the viewing slits is substantially orthogonal to the line of sight.

2. The holographic stereogram of claim 1 wherein the two-dimensional perspective views are transformed so that the user perceives the image to be substantially orthogonal to the user'"'"'s line of sight.

3. The holographic stereogram of claim 1 wherein the two-dimensional perspective views are transformed so that the user perceives the image to be rotated relative to the center of the recording medium.

4. The holographic stereogram of claim 1 wherein the two-dimensional perspective views are transformed so that user perceives the image to be (a) substantially orthogonal to the user'"'"'s line of sight and (b) rotated relative to the center of the recording medium.

5. A holographic stereogram which produces an image which is perceived by a user along a line of sight, said holographic stereogram comprising a recording medium which defines a plane disposed nonorthogonally to the line of sight and which contains a diffraction pattern which upon illumination produces a set of two-dimensional perspective views and a set of viewing slits, one viewing slit for each of the two-dimensional perspective views, said two-dimensional perspective views being transformed so that user perceives the image to be substantially orthogonal to the user'"'"'s line of sight.

6. The holographic stereogram of claim 5 wherein the two-dimensional perspective views are rotated so that the user perceives the image to be rotated relative to the center of the recording medium.

7. A holographic stereogram having an image contained therein which is viewable along a given line of sight said holographic stereogram comprising a recording medium adapted to be position non-orthogonally to the line of sight where the recording medium is exposed with a set of two-dimensional perspective views through a set of viewing slits, one viewing slit for each of the two-dimensional perspective views, said viewing slits being located in the vicinity of a user'"'"'s eyes such that an image formed by the viewing slits is substantially orthogonal to the line of sight.

8. The holographic stereogram according to claim 7 wherein the given line of sight is restricted over a range of angles relative to a vertical axis of the recording medium.

9. The holographic stereogram of claim 7 wherein the two-dimensional perspective views are transformed such that the image appears substantially orthogonally to the given line of sight.

10. The holographic stereogram of claim 7 wherein the two-dimensional perspective views are transformed so that the image appears to be rotated relative to the recording medium.