Patent ES-8601533-A1 (ES)
Title: Display device.
IPC: G02F1/13357
Filed: 1984-05-04
Abstract: A relatively shallow arrangement for providing illumination for a light scattering liquid crystal display cell employs a transparent sheet in optical contact with the front surface of the cell and a matt black sheet out of contact with the rear surface. The assembly acts as a light guide for light launched into the sides of the transparent sheet from strip lamps (9). - The only light escaping to reach the observer is a proportion of that scattered into non-guided directions by regions of liquid crystal layer selectively set into a scattering state. Pref. each strip lamp is a fluorescent tube strip lamp. Pref. the display device is addressable on a co-ordinate basis providing pixels defined by the intersection of a set of row electrodes on one side of the liquid crystal layer with a set of column electrodes on the other. (5pp Dwg.No.0/1) EPAB- EP-124816 B A liquid crystal display device of scattering mode type comprising a liquid crystal layer (1) as display layer disposed between a front and a rear transparent sheet (3 and 4,7) and a perimeter seal (2) display illumination means (9) which direct light through the side edge region of one of the two transparent sheets (3 and 4, 7) into this sheet and from there into the liquid crystal layer (1), the said illumination light being directed over the said display surface by reflections at the outer surfaces of the two transparent sheets (3, and 4, 7) and light being prevented from emerging through these outer surfaces, at least in the regions of the liquid crystal other than those switched into the scattering condition, by directing the illumination light by total reflection at the outer surfaces of both transparent sheets (3 and 4,7), whereas the light scattered in the regions of the liquid crystal layer switched into the scattering condition emerges from the display device from the front side and a backing sheet (8) spaced from the rear transparent sheet (3) and having, at least in the region of the display surface, a dark coloured surface as optical background, characterised in that the two transparent sheets (3 and 4, 7) have different thicknesses and in that the thicker sheet (4, 7) forms the front sheet of the display device. (7pp) GBAB- GB2139392 B A display device which has an electronically addressable layer and which incorporates means for directing light into that layer such that the light is prevented by total internal reflection from emerging from the display area of the device unless scattered by one or more selected regions of the layer, whereby such scattering regions are rendered visible against a background of contrasting appearance. USAB- US4626074 A A transparent sheet is in optical contact with the front surface of a display cell with a matt black sheet out of contact with the rear surface. The assembly acts as a guide for light launched into at least one of the transparent sheets from a one strip lamp. The only light escaping from the display, etc. in the direction of the observer is a proportional of that scattered into non-guided directions by regions of liquid crystal layer selectively set into a scattering state. - Optical contact, which is required to prevent losses at the interface between the two components, achieved by an optical coupling layer which may be an adhesive layer or a layer of a low vapour liquid.