Multicolor image memory

• US 3,881,800 A
• Filed: 05/30/1974
• Issued: 05/06/1975
• Est. Priority Date: 03/30/1972
• Status: Expired due to Term

• Current Assignee: Albert A. Friesem
• Original Assignee: Albert A. Friesem
• Inventors: Friesem, Albert A.
• Primary Examiner(s): Stern, Ronald J.
• Assistant Examiner(s): Henry, Jon W.
• Application Number:
  US05/474,782
• Time in Patent Office: 341 Days
• Field of Search: 350/3.5,162SF,317,117,126 353/121,122,84 354/101-103 352/66,67 250/329,458,461 358/2,60 355/2,77
• US Class Current: 359/25
• CPC Class Codes: F21K 2/00 Non-electric light sources using luminescence using excitation by radioactivity G21H3/02, H01J65/06, H01J65/08; using excitation by an external electromagnetic field or by external corpuscular radiation H01J65/04; Light sources using electrochemiluminescence
• CPC Class Codes: G02F 1/23 for the control of the colour G02F1/03 - G02F1/21 take precedence
• CPC Class Codes: G02F 2/02 Frequency-changing of light, e.g. by quantum counters
• CPC Class Codes: G03B 21/567 for colour projection G03B21/58, G03B21/60 take precedence
• CPC Class Codes: G03B 33/10 Simultaneous recording or projection G03B33/02, G03B33/04 G03B33/06 take precedence
• CPC Class Codes: G03H 1/16 using Fourier transform G03H1/10, G03H1/12, G03H1/14 take precedence; analogue computers G06G, e.g. G06G7/19
• CPC Class Codes: H04N 9/3108 by using a single electronic spatial light modulator

Abstract

A multicolor display system including a viewing screen having a multiplicity of closely spaced photoluminescent segments thereon in a regular array of alternating red, blue and green segments. A hologram which was recorded at or near the Fourier transform plane of the input information is positioned relative to the screen to project an image of the recorded information thereon when the hologram is illuminated by a readout beam. The information is recorded in a coded format representative of multiple colors contained in the original subject from which the information was derived.

Claims

1. A method comprising the steps of:

providing an array of a plurality of groups of interleaved photoluminescent segments each group emitting a different one of a plurality of colors, focusing the emitted light to an image location, providing at the image location a partially transparent multicolor original image which is to be recorded, and modulating the emitted light in accordance with the intensity of each of the colors of the image to be recorded by passing the radiated light through said partially transparent image, recording the modulated light pattern on a photosensitive recording surface proximate said original image, producing a second recording from the photosensitive recording surface and having information content based upon the original image to be recorded, illuminating the second recording with a readout light to cast an image modulated in accordance with the second recording upon an array of photoluminescent segments similar in color emission properties and arrangement to the first mentioned array so that all of the portions of the second recording which contain information about the same color in the original image transmit light to photoluminescent segments all of which emit the same color.

2. A method as defined in claim 1 and wherein said second recording is photographically developed transparency of the first recording.

3. A method as defined in claim 1 and wherein said second recording is a hologram and said readout light is an off-axis coherent light beam for holographically reading said second recording, and further comprising the following steps for producing the hologram:

producing from said first recording an intermediate recording comprising a photographically developed transparency, passing coherent light through said intermediate transparency and imaging it onto a hologram recording surface, simultaneously directing a coherent off-axis reference beam onto said hologram recording surface to produce said hologram.