Patent · US Expired

Virtual image display apparatus

US4294515A · kind A · utility

11Cited by
19References
18Claims
0Family size

Inventor

Key dates

Filing dateMar 23, 1979
Grant dateOct 13, 1981
Priority date
Expiry dateMar 23, 1999

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B2027/0169
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A virtual image display device for alpha-numeric and pictorial information. A concave spherical mirror segment magnifies and reflects an image from an image source. The image source is mounted between the focus of the mirror and the said mirror and parallel to its optical axis. The virtual image thereby formed is visible to the viewer in front of the mirror. In related embodiments, the concave mirror segment can be made partially reflective and placed in front of a camera lens to allow a camera to photograph through it. A planar mirror can also be included to fold the light path of the display and thereby reduce the size of the apparatus.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.