Endoscope or borescope stereo viewing system

• US 5,222,477 A
• Filed: 09/30/1991
• Issued: 06/29/1993
• Est. Priority Date: 09/30/1991
• Status: Expired due to Term

• Current Assignee: Welch Allyn Incorporated
• Original Assignee: Welch Allyn Incorporated
• Inventors: Lia, Raymond A.
• Primary Examiner(s): RICHARD, KAREN
• Assistant Examiner(s): Jalbert, Karen Ann
• Application Number:
  US07/767,796
• Time in Patent Office: 638 Days
• Field of Search: 128/6, 128/4, 358/98, 358/88, 358/91, 358/92, 358/3
• US Class Current: 600/111
• CPC Class Codes: A61B 1/00193 adapted for stereoscopic vision
• CPC Class Codes: A61B 1/05 characterised by the image sensor, e.g. camera, being in the distal end portion
• CPC Class Codes: G02B 30/24 involving temporal multiplexing, e.g. using sequentially activated left and right shutters
• CPC Class Codes: H04N 13/211 using temporal multiplexing
• CPC Class Codes: H04N 13/214 using spectral multiplexing
• CPC Class Codes: H04N 13/296 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 13/334 using spectral multiplexing
• CPC Class Codes: H04N 13/341 using temporal multiplexing
• CPC Class Codes: H04N 13/398 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 23/555 for picking-up images in sites, inaccessible due to their dimensions or hazardous conditions, e.g. endoscopes or borescopes

Abstract

A stereo imaging and viewing system for a borescope or endoscope employs a miniature camera assembly in which are disposed a CCD imager or equivalent imager, a wide-angle focusing lens assembly with an effective aperture on the order of about f/2 or wider, and an aperture plate interposed in the optical path of the camera and adjacent the lens assembly. The aperture plate has left and right pupils therein situated on opposite sides of the optic axis of the lens assembly. The pupils are separated from one another by a predetermined pupil distance that is somewhat smaller than the lens diameter. The left image passes through the left pupil and is focused through a corresponding portion of the lens assembly onto the image plane of the imager and a right image passes through the right pupil and is focused by a corresponding portion of the lens assembly onto the image plane of the imager. A selective mechanism, such as alternate shutters or distinct color filters, separate the left and right views of the target sequentially. Left and right views are then presented to a display device for viewing the left and right views stereoscopically.

Claims

1. Stereoscopic imaging and viewing system for borescope or endoscope, comprising a miniature camera assembly that includes an imager having an image plane, a focusing lens assembly of a predetermined diameter and an effective aperture on the order of about f/2 or wider for focusing, at a location on an optic axis of the lens assembly, and on the image plane of said imager an image of a three-dimensional target in the viewing field of said camera assembly said imager being fixed against transverse movement with respect to said optic axis;

an aperture plate interposed in the optical path of said camera assembly adjacent said lens assembly, having left and right pupils therein situated on opposite sides of the optic axis of said lens assembly and separated from one another by a predetermined pupil distance less than said lens assembly diameter, such that a left image passes through the left pupil and is focussed on the imager by a corresponding portion of said lens assembly on said image plane and a right image passes through the right pupil and is focussed on the imager by a corresponding portion of said lens assembly on said image plane; and

selective means for alternately admitting light through said pupils and forming said left image and said right image on said imager alternately to produce distinguishable left-eye and right-eye views of the target; and

viewing means coupled to said imager to receive the left and right images therefrom and visually display said left-eye and right-eye views of the target to produce a stereoscopic view of said three-dimensional target.

2. Stereoscopic imaging and viewing system of claim 1, wherein said imager and said lens assembly are controllably movable towards and away from each other with said aperture plate remaining with the lens assembly, such that relative movement of the focusing lens and imager plane of the imager simultaneously converges the left and right images.

3. Stereoscopic imaging and viewing system of claim 1 wherein said selective means includes a pair of shutter mechanisms which open alternately to produce the left and right images sequentially.

4. Stereoscopic imaging and viewing system of claim 3 wherein said shutter mechanisms include liquid crystal shutters.

5. Stereoscopic imaging and viewing system of claim 1 wherein said selective means includes left and right optical filters of distinct wavelengths disposed in the optical path of the associated left and right pupils.

6. Stereoscopic imaging and viewing system of claim 1 wherein said viewing means includes a video screen producing said right and left images in distinct colors thereon, and also comprises viewing glasses having left and right lenses of said distinct colors.

7. Stereoscopic imaging and viewing system of claim 1 wherein said viewing means comprises video processing means that includes a stereoscopic viewer with separate left and right images on which said left-eye and right-eye views are respectively presented.