The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 11, 1996
Filed:
Dec. 09, 1993
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
A head-mounted display apparatus designed so that the utilization efficiency of display light from an image display device is increased and it is possible to control the brightness of an outside, real world image and also possible to shut off light from the outside. A liquid crystal display device (2) is disposed so that the direction of polarization of light emerging from the liquid crystal display device (2) is parallel to the plane of incidence on a polarization beam splitter (5) disposed in front of an observer's eye. The light emerging from the liquid crystal display device (2) is transmitted by the PBS (5) and reflected by a concave mirror (3) through a quarter-wave plate (6) disposed on the exit side of the PBS (5). The reflected light passes through the quarter-wave plate (6) and enters the PBS (5) again. Since the display light passes through the quarter-wave plate (6) twice during the round-trip travel, almost all the display light is reflected by the PBS (5) to enter the observer's eye. Accordingly, the light emerging from the liquid crystal display device (2) reaches the observer's eye with substantially no loss of light. With regard to light (4) from the outside world, a half of the incident light is reflected by the PBS (5), and the other half reaches the observer's eye.