Virtual image display having a high efficiency grid beamsplitter
US5383053A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1992 |
| Grant date | Jan 17, 1995 |
| Priority date | — |
| Expiry date | Apr 7, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0118
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A focusable virtual image display system employing a focusable image source such as a cathode ray tube and imaging optics to provide a virtual image. The virtual image is viewable by a user and its effective range may be changed without changing the apparent field of view or resolution. By placing the focus point of the imaging optics at the design eye, the image source is moved backwards and forwards, thus effectively changing the range of the virtual image observed by the user without changing the apparent field of view or resolution. The present invention allows the user to adjust the focus position of the virtual image of the image source by moving it relative to the imaging optics, while maintaining the size and resolution of the image. If the user wants to move the image further away, when the image source is moved, the imaging optics moves the virtual image further away and magnifies the image such that the angular field of view stays the same. The user cannot distinguish between the sizes, although the focus will be more comfortable for a particular accommodation range. The relative cost of the virtual image display system is relatively less expensive than large screen moni…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.