IE914557A1

IE914557A1 - Modular display device formed of liquid crystal cells

Info

Publication number: IE914557A1
Application number: IE455791A
Authority: IE
Inventors: Bernd Brauer
Original assignee: Krone Ag
Priority date: 1991-04-27
Filing date: 1991-12-23
Publication date: 1992-11-04
Also published as: PT100428A; DE4113901A1; EP0511432A3; EP0511432A2

Abstract

A description is given of a modular display device formed by liquid crystal cells. The liquid crystal cells in each case have a liquid crystal layer (1), which is enclosed between two parallel glass substrates (2, 3) and a sealing frame (8) connecting their rims, as well as transparent electrodes (4, 5) on the faces of the glass substrates facing the liquid crystal layer. In order to connect them to external control electronics, the electrodes are guided through the sealing frame and contacted outside thereof to a flexible conductive foil (9). In this arrangement, the contact region between the electrodes and the conductive foil extends perpendicular to the plane of the glass substrate, so that the contact surface has minimum dimensions in the display plane.

Description

MODULAR DISPLAY DEVICE FORMED OF LIQUID CRYSTAL CELLS The invention relates to a display device according to the preamble of claim 1.

Large-area display devices commonly require a modular system, since the technologically achievable areas of a liquid crystal matrix are limited. In a modular construction, however, the contacting surfaces arranged in the display device will considerably irritate the user.

From DE 38 40 836 Al, a liquid crystal display device is known in the art, with a display element having several liquid crystal ceils, wherein electrical connection positions for the liquid crystal cells extend to the edge of the display element. With the connection positions disposed in the plane of the display element, conductive tracks of a multi-layer, flexible connection piece are contacted. This is bent out, from the plane of the display element, around the edge thereof, so that the surface occupied by the contacting in this plane, is held relatively small. It is, however, still regarded as distinctively irritating.

The invention is based on the object, therefore, to provide a modular display device formed of liquid crystal cells, wherein the liquid crystal cells comprise a liquid crystal layer enclosed between two parallel glass substrates and a sealing frame connecting the borders thereof, and transparent electrodes are provided on the surfaces of the glass substrates directed toward the liquid crystal layer, said electrodes being guided, for connection to an external control circuitry, through the sealing frame and being contacted, outside thereto, with a flexible conductor foil, wherein the surfaces for -2contacting disposed in the display plane are held even sma11er.

The solution of this object is achieved by the characterising feature of claim 1. Further advantageous embodiments of the invention can be found in the subclaims.

By that the contact zone between the electrodes and the conductor foil extends perpendicularly to the plane of the glass substrates, the contact surface in the display plane has minimum dimensions, so that the user will nearly not remark it.

In the following, the invention is described in more detail, based on an embodiment represented in the drawing. There is shown a longitudinal section through the border area of two adjacent liquid crystal cells with an electrical connection for one of such cells.

The liquid crystal cells consist, in known manner, of a liquid crystal 1, two glass substrates 2 and 3 enclosing the latter, light-transmissive electrodes 4 and 5 of indium tin oxide (ITO) each on the surface of the glass substrate 2 and 3 directed toward the liquid crystal, an analyzer 6, a polarizer 7 and a sealing frame 8 limiting the intermediate space between the glass substrates 2 and 3 at the border.

The glass substrates 2 and 3 and the sealing frame 8 form a tight chamber for receiving the liquid crystal 1. The electrodes 4 and 5 are extended toward outside between the glass substrates 4 and 5 and the sealing frame 8 for connection to the control circuitry.

The electrical connection between the electrodes 4 and 5 and the control circuitry is performed over a flexible conductor foil, the individual conductor tracks of which being contacted with the electrodes of the liquid crystal cells. The conductor foil 9 extends, in the area of the liquid crystal cells, perpendicularly to the plane of the glass substrates 2 and 3 or to the display plane, resp., and the conductor foil 9 extends also in this direction . -3The contact between the electrodes 4 and 5 and the conductor foil 9 can be achieved in different ways. In the figure, a contact adhesive 10 is shown, which is applied to the side of the sealing frame 9 directed away from the liquid crystal 1, and connects, thus, the electrodes 4 and 5 with the conductor foil 9. For instance, the glass substrates 2 and 3 can also be evaporated on the border surfaces being perpendicular to its plane with a layer of metal or indium oxide being in connection with the electrodes 4 and 5, and then, this layer is soldered or glued with the circuit tracks of the conductor foil 9.

Another possibility is the connection of the electrodes 4 and 5 with the conductor foil 9 by a polymer, which has been made conductive by laser irradiation. Finally, instead of metal evaporation, the border surfaces of the glass substrates 2 and 3 can also be printed-over with a conductive resin.

For mechanically stabilizing and guiding the conductor foil 9 serves a box-type holding frame 11, which is fixed by an adhesive 12 to the rear side of the liquid crystal cells. The conductor foil 9 is fixedly glued to the holding frame, so that it is not subjected to tensional forces. In a recess of the holding frame is provided an integrated circuit 13 for controlling, which is contacted in TAB technique (tape automatic bonding) with the conductor foil 9. The holding frame 11 is designed such that it does not need more space, in the direction of the display plane, than the sealing frame 8. At the lower end of the holding frame 11, there is provided a bus connection 14 being in contact with the conductor foil 9.

Claims

1. Patent Claims

1. A modular display device formed of liquid crystal cells, wherein the liquid crystal cells comprise a liquid crystal layer enclosed between two parallel glass substrates and a sealing frame connecting the borders thereof, and transparent electrodes are provided on the surfaces of the glass substrates directed toward the liquid crystal layer, said electrodes being guided, for connection to an external control circuitry, through the sealing frame and being contacted, outside thereto, with a flexible conductor foil, characterized by that the contact zone between the electrodes (4, 5) and the conductor foil (9) extends perpendicularly to the plane of the glass substrates (2, 3).

2. A display device according to claim 1, characterized by that the glass substrates (2, 3) comprise an electrically conductive coating connected, on the border surfaces being perpendicular to the plane of said glass substrates, with the electrodes (3, 4), and also fixedly connected with the conductor foil (9).

3. A display device according to claim 2, characterized by that the border surfaces of the glass substrates (2, 3) are evaporated with a layer of metal or of the material of the electrodes (4, 5), which are soldered or glued to the conductor foil (9).

4. A display device according to claim 2, characterized by that the border surfaces of the glass substrates (2, 3) are printed-over with a conductive resin. -55. A display device according to claim 1, characterized by that on the side of the sealing frame (8) directed away from the liquid crystal layer (1), a contact adhesive layer (10) is applied, which is in electrical contact with the conductor foil (9j.

5. 6. A display device according to claim 1, characterized by that the border surfaces of the glass substrates (2, 3) and/or the surfaces of the sealing frame (8) directed away from the liquid crystal layer (1) are coated with a polymer having been made conductive with laser irradiation, the said polymer being in electrical contact with the conductor foil (9).

6. 7. A display device according to one of claims 1 to characterized by that adjacent to the liquid crystal cell, a box-type holding frame (11) is provided for guiding and strain-relieving the conductor foil (9).

7.

8. A display device according to any preceding claim substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings Dated this the 23rd day of December, 1991