# US 5,349,469 A · Optical mode switching system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,349,469 A - Document ID: US5349469A - Status: Granted - Kind: A - Application number: 07/994,578 - Filed: 1992-12-22 - Granted: 1994-09-20 - Earliest claimed: 1992-12-22 - Assignees: Hughes Aircraft Company - Inventors: Melvin Francis - Web page: https://patentgrep.com/patent/US5349469A ## CPC - G02B 23/14: Viewfinders (for photographic apparatus G03B13/02) - G02B 23/00: Telescopes, e.g. binoculars; Periscopes; Instruments for viewing the inside of hollow bodies; Viewfinders; Optical aiming or sighting devices - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An optic mode switching system 14 provides for switching between two or more optic modes by movement of an eye 24. The system 14 comprises a first optic system 10 which provides a first image at a first position 25. The system 14 also comprises a second optic system 12 which provides a second image at a second position 40. The viewer switches optic modes by moving eye 24 from the first position 25 in the eyepiece to the second position 40 during viewing. ## Claims ### Claim 1 An optical mode switching system for providing a plurality of closely spaced exit pupils to facilitate separate views of each exit pupil by a viewer's eye, comprising: a first optic system for providing a first image at a first position adjacent a first exit pupil; and N additional optic systems for providing N separate images at N corresponding additional exit pupils closely spaced to said first exit pupil, where N is an integer greater than zero, each of said N optic systems having a line-of-sight substantially parallel to a line-of-sight of said first optic system, whereby each of the N images is viewable by the viewer's eye with little eye movement and essentially no movement of the viewer's head. ### Claim 2 (depends on 1) The optical mode switching system of claim 1, wherein each of said N exit pupil are adjacent to said first exit pupil. ### Claim 3 (depends on 1) The optical mode switching system of claim 1, wherein N is equal to 1. ### Claim 4 An optical mode switching system for providing a plurality of closely spaced exit pupils to facilitate separate views of each exit pupil by a viewer's eye, comprising: a first optic system for providing a first image at a first position adjacent to a first exit pupil; and N additional optic systems for providing N separate images at N corresponding additional exit pupils, closely spaced to said first exit pupil, where N is an integer greater than zero, each of said N optic systems having a line-of-sight substantially parallel to a line-of-sight of said first optic system, each of said N optic systems forming an exit pupil which is inclined with respect to said first exit pupil, whereby each of the N images is viewable by the viewer's eye with little eye movement and essentially no movement of the viewer's head. ### Claim 5 An optical mode switching system providing a plurality of closely spaced exit pupils to facilitate separate views of each exit pupil by a viewer's eye, comprising: a first optic system comprising: a first objective lens, an inverting prism, and a first eyepiece, wherein the light from said image enters said first optical system by passing through said first objective lens, through said inverting prism and through said first eyepiece so as to provide a first exit pupil; and N additional optic systems for providing N corresponding additional exit pupils, where N is an integer greater than zero, each of said N exit pupils being adjacent to said first exit pupil, each optic system of said N additional optic systems further comprises: an objective lens, a field lens, a relay lens, an inclining prism and an eyepiece, wherein the light from an image enters said optic system by passing through said objective lens, through said field lens, through said relay lens, through said inclining prism, through said eyepiece so as to provide said corresponding additional exit pupil, wherein each objective lens of each optic system of said N optic systems has a line-of-sight substantially parallel to a line-of-sight of said objective lens of said first optic system. ### Claim 6 (depends on 5) The optical mode switching system of claim 5, wherein N is 1. ### Claim 7 An optical mode switching system providing a plurality of closely spaced exit pupils to facilitate separate views of each exit pupil by a viewer's eye, comprising: a first optic system comprising: a first objective lens, an inverting prism, and a first eyepiece, wherein the light from said image enters said first optical system by passing through said first objective lens, through said inverting prism and through said first eyepiece so as to provide a first exit pupil; and a second optic system comprising: a second objective lens, a first field lens, a first relay lens, a first inclining prism and a second eyepiece, wherein the light from said image enters said second optic system by passing through said second objective lens, through said first field lens, through said first relay lens, through said first inclining prism, through said second eyepiece so as to provide a second exit pupil adjacent to said first exit pupil and wherein said second objective lens has a line-of-sight substantially parallel to a line-of-sight of said first objective lens. ### Claim 8 A plurality of distinct optic systems for providing a plurality of separate images at a plurality of positions adjacent corresponding exit pupils, said distinct optic systems having lines-of-sight substantially parallel to each other such that each of said separate images is viewable by a viewer's eye with little eye movement and essentially no movement of the viewer's head. ### Claim 9 An optical mode switching system comprising: a first optic system for providing a first image at a first position adjacent a first exit pupil and a second optic system for providing a second image at a second position adjacent a second exit pupil, closely spaced to said first exit pupil, whereby said first image and said second image are viewable by a viewer with little eye movement and essentially no movement of the viewer's head. ### Claim 10 (depends on 9) The invention of claim 9 further including means for inclining the line-of-sight of said first optical system relative to the line-of-sight of the second optical system. ### Claim 11 (depends on 10) The invention of claim 10 wherein said means for inclining the line-of-sight of said first optical system relative to the line-of-sight of the second optical system includes an inclining prism.