Browse Prior Art Database

OPTICAL CONNECTION TO LCD, ETC

IP.com Disclosure Number: IPCOM000025982D
Original Publication Date: 1989-Jun-30
Included in the Prior Art Database: 2004-Apr-04
Document File: 2 page(s) / 89K

Publishing Venue

Xerox Disclosure Journal

Abstract

It is usually expensive and difficult to connect signals to a liquid crystal display, especially when a large number of signals are required. One way to reduce this problem is to put a small control chip on the display substrate. The signals can then be reduced to a power line signal, a ground line signal, and a serial communication line signal. A simpler decode can be used if only a few elements are being controlled (4 bits can give 16 items individually). To make these connections, wires can be bonded to the glass, a pressure connection can be used, or a conductive polymer is mounted between the glass and the circuit board. If the display must be moved (or interchanged) or if it is inconvenient to mount a light behind it, the job of connecting it becomes very difficult - the more lines to connect, the more difficult.

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KEROX DISCLOSURE JOURNAL

OPTICAL CONNECTION TO LC D, ETC. Craig A. Smith U.S. C1.355/14R
V. Joseph Hull

Proposed Classification

Int. C1. G03g 15/00

Volume 14 Number 3 May/June 1989 149

[This page contains 1 picture or other non-text object]

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OPTICAL CONNECTION TO LCD, ETC. (Cont'd)

It is usually expensive and difficult to connect signals to a liquid crystal display, especially when a large number of signals are required. One way to reduce this problem is to put a small control chip on the display substrate. The signals can then be reduced to a power line signal, a ground line signal, and a serial communication line signal. A simpler decode can be used if only a few elements are being controlled (4 bits can give 16 items individually). To make these connections, wires can be bonded to the glass, a pressure connection can be used, or a conductive polymer is mounted between the glass and the circuit board. If the display must be moved (or interchanged) or if it is inconvenient to mount a light behind it, the job of connecting it becomes very difficult - the more lines to connect, the more difficult.

There are two types of connections required - a power source and signal source. In the case of a direct-addressed display each signal source is its own power source. It is proposed to make both of these connections optically.

As shown in the Figure, an array of LED'S 10 on the PWB (or other mounting surface) sends a coded signal to an array of photodetectors 1...