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:
Aug. 07, 2001
Filed:
Dec. 04, 1997
Richard Robert Moseley, Horsham, GB;
Graham John Woodgate, Henley-on-Thames, GB;
David Ezra, Wallingford, GB;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A directional display comprises a display arrangement such as a spatial light modulator and a rear parallax barrier illuminated by a suitable backlight. The spatial light modulator and the parallax barrier cooperate to produce Fresnel diffraction which results in spatially non-uniform brightness across viewing windows of the display. Also, where the spatial light modulator has pixels of non-constant vertical aperture, further variations in the intensity profile at the windows occurs. In order to compensate for this, a mask is provided, for instance between the parallax barrier and the backlight. The mask cooperates with the parallax barrier to produce an intensity pattern having variations which are the inverse of the variations in intensity pattern produced by the parallax barrier and the spatial light modulator. The variations are superimposed and substantially cancel each other out so as to result in viewing windows which have substantially uniform light intensities.