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Gray-levels in a roll blind display

IP.com Disclosure Number: IPCOM000030856D
Publication Date: 2004-Aug-30
Document File: 1 page(s) / 33K

Publishing Venue

The IP.com Prior Art Database

Abstract

ID695075 and ID697659

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 51% of the total text.

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ID 695075, ID 697659

Gray-levels in a roll blind display

    In Figure 1 the roll blind principle has been shown. A substrate is covered with ITO transparent column electrodes. These are covered with a thin dielectric to electrically isolate the column electrodes. The thin dielectric can be made to function as a color filter. A foil is deposited which is covered with a conductive row electrode. This foil is glued to the dielectric on one side of every column of pixels. The row electrodes are in between the dielectric and the foil. In reflective mode the front side of the foil is covered with a white layer to reflect the ambient light. Rectangular cuts are made on three sides after which it is heated to shrink the foil, which in turn rolls up. This opens up the pixel giving a white pixel in transmissive mode or a dark pixel in reflective mode. When applying a certain voltage difference between the columns and the rows, the electrostatic forces rolls down the foil to the substrate, thereby covering the pixel and creating a dark pixel in transmissive mode or a white pixel in reflective mode.

    In a reflective display device the topside of the foil is reflective (white, red, green or blue). The bottom side is black. When a pixel is open the topside is shown over the full pixel (except for the black matrix, which is obtained by using a black substrate). When a pixel is closed, the pixel rolls up and shows the bottom side of the roll and simultaneously, the black substrate is shown. The same can be obtained by reversing all the layers and using a reflective (white, red, green or blue) substrate.

    To make gray levels the Roll blind foil can be partially rolled down. In Figure 2, a method is shown to do so. A pixel has three electrodes plus a foil counter electrode. Two electrodes are the row electrodes, which are on the top and bottom side...