EP0337555A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Display device
Assignee: Koninklijke Philips NV
•
Filing: 1989-04-07
•
Granted: —
•
Expires: 2009-04-07
Abstract
Abstract The light output of a colour LCD (10) is considerably increased by arranging dichroic mirrors (31, 32, 33) registering with the pixels (20), which mirrors pass the colour suitable for the pixel and reflect the other light so that it can again be used after reflection on a reflective surface (45).
Inventors
- 👤 Adrianus Johannes St. M. De Vaan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 13:55
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/1336; G02F1/133621; G02F1/133509; G02F1/133514
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
99 words
A display device, particularly a liquid crystal display device comprising an electro-optical medium between two transparent, parallel supporting plates provided with a pattern of pixels, said device having a light element, characterized in that the light element can emit a light spectrum and in that the device, registering with the pixels, comprises a pattern of dichroic mirrors which substantially pass one part of the light spectrum associated with corresponding pixels and substantially reflect the other part in the direction of an element reflecting in such a way that the reflected light is reflected in the direction of the pixels.
Claim 2
Dependent Claim
99 words
A display device, particularly a liquid crystal display device comprising an electro-optical medium between two transparent, parallel supporting plates provided with a pattern of pixels, said device having a light element, characterized in that the light element can emit a light spectrum and in that the device, registering with the pixels, comprises a pattern of dichroic mirrors which substantially pass one part of the light spectrum associated with corresponding pixels and substantially reflect the other part in the direction of an element reflecting in such a way that the reflected light is reflected in the direction of the pixels.
Claim 3
Dependent Claim
42 words
A display device as claimed in Claim 1, characterized in that the display device comprises drive circuits which generate respective sub-pictures for each of a number of composite colours via pixels registering with dichroic mirrors associated with each of the composite colours.
Claim 4
Dependent Claim
52 words
A display device as claimed in Claim 1 or 2, characterized in that the device comprises a colour filter which is divided into filter elements registering with the dichroic mirrors and the pixels, the colours of filter elements of the colour filter corresponding to the colours passed by the associated dichroic mirrors.
Claim 5
Dependent Claim
21 words
A display device as claimed in Claim 2 or 3, characterized in that the composite colours are red, green and blue.
Claim 6
Dependent Claim
31 words
A display device as claimed in any one of Claims 1 to 4, characterized in that the inner side of at least the rear wall of the light element is reflective.
Claim 7
Dependent Claim
48 words
A display device as claimed in Claim 5, characterized in that the rear wall of the light element is coated with a material whose optical axis is parallel to the direction of polarization of a polarizer associated with the display cell on the side of the light element.
Claim 8
Dependent Claim
54 words
A display device as claimed in any one of the preceding Claims, characterized in that the light element comprises a diffusor which is provided with reflective metal particles whose optical axes are substantially parallel to the direction of polarization of a polarizer associated with the display cell on the side of the light element.
Claim 9
Dependent Claim
36 words
A display device as claimed in Claim 7, characterized in that the metal particles have a higher surface density at an area which, viewed in perpendicular projection, coincides with a light source in the light element.
Claim 10
Independent Claim
40 words
A device for projection display, characterized in that the device comprises a display device as claimed in any one of Claims 1 to 8 and optical means for imaging an image generated in the display cell in a projection plane.
Claim 11
Dependent Claim
71 words
A display cell for use in a display device as claimed in any one of the preceding Claims, comprising an electro-optical medium between two transparent, parallel supporting plates provided with a pattern of pixels, characterized in that the display cell, registering with the pixels, comprises a pattern of dichroic mirrors which, dependent on their position in the pattern, substantially pass one part of the light spectrum and reflect the other part.
Claim 12
Dependent Claim
44 words
A display cell as claimed in Claim 10, characterized in that it comprises a colour filter which is divided into filter elements registering with the dichroic mirrors and the pixels, whilst colours of filter elements correspond to colours passed by the associated dichroic mirrors.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.