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Optical Graphic Display System

IP.com Disclosure Number: IPCOM000093174D
Original Publication Date: 1967-Jun-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 3 page(s) / 45K

Publishing Venue

IBM

Related People

Harris, TJ: AUTHOR

Abstract

The exchange of graphic information between a display and a computer is accomplished by utilizing optical beams in this system. A mirror pencil is employed for writing into a computer memory with light beams. The system can also be employed for copying andprinting data.

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Optical Graphic Display System

The exchange of graphic information between a display and a computer is accomplished by utilizing optical beams in this system.

A mirror pencil is employed for writing into a computer memory with light beams. The system can also be employed for copying andprinting data.

Information is displayed on output screen 1 under the control of digitally accessed light deflector 2. The latter is controlled to perform a scan operation by vertical and horizontal driver circuits in registers 3 and 4. Clock 5 operating at approximately 30 mc. is directly connected to register 4 to scan each output position thirty times a second. The clock signal provided to register 3 is reduced at 6 by a factor of 1024. This reduction causes the vertical position line to shift for every 1024 horizontal positions. Registers 3 and 4 are coupled through connections 8 and 9 and appropriate decoder and drive circuits 10 and 11 to memory 7. For every horizontal and vertical address in registers 3 and 4, there is a corresponding position on screen 1 and a corresponding cell in memory 7.

To display the information stored in memory 7, switch D is connected in an on position. For a given address in registers 3 and 4 the corresponding cell in memory 7 is interrogated. If a 1 is stored in the interrogated cell, an output pulse at 12 operates electro-optic shutter 13 through pulse shaping and driver circuit 14.

Light from laser 15 is transmitted through deflector 2 to the corresponding position on screen 1. If a 0 is stored in the interrogated memory cell, an output is not provided at 12 and there is no light transmission to screen 1. At the same time, the output signal at 12 is supplied to gate 16 which activates circuits 10 and 11 to rewrite the 1 in the interrogated cell.

During erasure of the information stored in a particular memory cell, switches D and E are connected in an on condition. Light pencil 17, having a mirror at its end, is positioned over the corresponding spot on screen 1. When the beam from laser 15 is scanned to this spot, pencil 17 reflects it back through deflector 2 and beam stop 18 to beam splitter 19. The latter directs it to photodetector 20. An output pulse from photodetector 20 inhibits gate 16 from generating a signal for circuits 10 and 11. Thus, a 1 is not rewritten in the interrogated cell. If pencil I7 is positioned over a spot on screen 1 which does not contain a light output, there is no reflected light supplied to photodetect...