Image registering in color at low light intensity

• US 5,483,379 A
• Filed: 11/12/1993
• Issued: 01/09/1996
• Est. Priority Date: 05/14/1991
• Status: Expired due to Fees

• Current Assignee: Forskarpatent i Syd AB (Government of Sweden)
• Original Assignee: Jonas Johansson, Sune Svanberg
• Inventors: Svanberg, Sune, Johansson, Jonas
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): MACK, RICKY LEVERN
• Application Number:
  US08/146,120
• Time in Patent Office: 788 Days
• Field of Search: 359/634, 359/364, 359/353, 359/359, 250/214 VT, 250/207, 250/214 AL, 348/217, 348/216, 348/218
• US Class Current: 359/634
• CPC Class Codes: G02B 23/12 with means for image conversion or intensification
• CPC Class Codes: H01J 2229/8926 Active components, e.g. LCD's, indicators, illuminators and moving devices
• CPC Class Codes: H01J 29/89 Optical or photographic arrangements structurally combined or co-operating with the vessel H01J29/866 and H01J29/868 take precedence
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

In a combination of a focusing optics for imaging a scene onto an image intensifier and means as an ocular for perceiving the intensified image of the scene, a system of input filters obtains color separation in multiplex for feeding to a sole image intensifier. The multiplexed color separated intensified images are joined into a color image. In a system with time multiplexing, a filter disc on the input side rotates in common with another filter disc on the output side. In another system with space multiplexing, the color separated images are obtained by beam splitting side by side on the input surface of the image intensifier and are then combined either with analogous means (filters and reverse beam splitter) or with TV methods.

Claims

1. A device for obtaining a viewable image from a weakly illuminating scene comprising a first optical system and image intensifier means for imaging the scene on to an image intensifier input surface, and a second optical system for perceiving an intensified image on an image intensifier output surface, said first optical system comprising a plurality of mutually different input color filters, and a beam-splitter for obtaining a plurality of images spacedly and simultaneously on to said input surface, filtered through one of said input filters, respectively, said image intensifier means comprising a sole image intensifier, multiplexer means which are spaced-multiplexing for obtaining in multiplex through said filters a plurality of color-separated intensified images on the image intensifier output surface, and means for obtaining a composite color image from said plurality of color-separated intensified images.

2. A device as claimed in claim 1 wherein said beam-splitter comprises a concave mirror which is cut up into portions which form small mutual angles, each said portion cooperating with a respective one of said input filters for creating said plurality of images on said input surface.

3. A device as claimed in claim, 2 wherein the output surface of the image intensifier is imaged by an optical system on to a charge coupled device which has an output connected to a computer joining said plurality of images into a color image.

4. A device as claimed in claim, 2 wherein the output surface of the image intensifier is provided with a reverse beam splitter for adding the respective images through filters for obtaining a color image.