Liquid crystal display device with reflective material that hides switching material

• US 7,009,668 B2
• Filed: 10/28/2003
• Issued: 03/07/2006
• Est. Priority Date: 06/06/2000
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Van De Witte, Peter, Pitt, Michael Geoffrey
• Primary Examiner(s): CHOWDHURY, TARIFUR RASHID
• Application Number:
  US10/695,144
• Publication Number:
  US 20040092196A1
• Time in Patent Office: 861 Days
• Field of Search: 349/96, 349/97, 349/106, 349/113, 349/115
• US Class Current: 349/113
• CPC Class Codes: C09K 19/586 Optically active dopants; chiral dopants
• CPC Class Codes: G02F 1/133516 Methods for their manufacture, e.g. printing, electro-deposition or photolithography
• CPC Class Codes: G02F 1/133533 Colour selective polarisers G02F1/1347 takes precedence

Abstract

In a method of manufacturing a liquid crystal device including a layer having a fixed cholesteric order, the patterned layer is manufactured by providing a layer comprising polymerizable cholesterically ordered material and a compound convertible by means of radiation from a non-converted to converted state. The pitch of the cholesterically ordered material is influenced by the compound in its converted state to a different extent than in its converted state. The polymerizable layer is then irradiated pattern-wise thus creating regions of different pitch. The irradiated layer is then polymerized and/or cross-linked to fix the cholesteric order thus obtained.

Claims

1. A reflective active matrix liquid crystal display device comprising

a liquid crystal layer dispersed between an active and a passive substrate plate,

the active substrate plate being present on the side opposite the viewing side and comprising

a plurality of optically transparent pixel electrodes and

a plurality of active switching elements for controlling the voltage supplied to said pixel electrodes,

the switching elements being spatially separated from, positioned subjacent and electrically connected to said plurality of pixel electrodes,

wherein the space separating the switching elements and the pixel electrodes is filled with an electrically insulating color selection layer which selectively reflects light of particular wavelengths and renders the switching elements invisible to the light reflected.

2. The liquid crystal display device of claim 1, wherein

a light-absorbing layer for absorbing light transmitted by the color selection layer is located between the color selection layer and the active switching elements.

3. The liquid crystal display device of claim 1, wherein

the color selection layer is patterned with discrete areas of at least two different reflective colors.

4. The liquid crystal display device of claim 3, wherein

the at least two different reflective colors include red, green, and blue.

5. The liquid crystal display device of claim 1, wherein

the switching elements are electrically connected to the pixel electrodes by vias that traverse the color selection layer.

6. The liquid crystal display device of claim 1, wherein

the pixel electrodes provide an area of light emission that corresponds to at least 85% of a total display area.

7. The liquid crystal display device of claim 1, wherein

an alignment of the passive substrate plate within the device is substantially independent of an alignment of the color selection layer.