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:
May. 22, 1990
Filed:
Aug. 12, 1988
John R Banbury, Fleet, GB;
Derek L Barter, Aldershot, GB;
Abstract
An optical system for a head-up display for example for producing a collimated image of a crt display on the external view of an aircraft pilot includes an optical relay unit including two elements (11,12) to produce a double fold in its optical axis to reduce the physical size of the relay unit. One of the two units (11), preferably of a diffractive type, is adapted to transmit light of the display color at a first angle of incidence and to reflect such light at a second angle of incidence. By use of a diffractive element having a narrow band reflectance, the system is extended to include embodiments for combining the display of two different color displays and a full color version using three crts is described.