Browse Prior Art Database

Beam Position Storage

IP.com Disclosure Number: IPCOM000094378D
Original Publication Date: 1966-Oct-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 61K

Publishing Venue

IBM

Related People

Johnston, DL: AUTHOR

Abstract

In many instances, such as in character recognition machines, it is desirable to store beam positions of the flying spot scanner. Every beam position can be related to horizontal and vertical detection drive voltages. The beam of cathode ray tube 10 is detected as horizontal and vertical deflection voltages are applied to detection coils 11 and 12 respectively from beam deflection circuit 15. Control circuit 20 provides drive control signals Right, Left, Up and Down to circuit 15.

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Beam Position Storage

In many instances, such as in character recognition machines, it is desirable to store beam positions of the flying spot scanner. Every beam position can be related to horizontal and vertical detection drive voltages. The beam of cathode ray tube 10 is detected as horizontal and vertical deflection voltages are applied to detection coils 11 and 12 respectively from beam deflection circuit 15. Control circuit 20 provides drive control signals Right, Left, Up and Down to circuit 15.

Horizontal and vertical servo and store circuits 30 and 40 are substantially the same. Only the horizontal circuit 30 is shown in detail. During the servoing operation, latch 31 is set in response to a servo signal from 20. The set output of 31 conditions And's 32 and 33. The outputs of And's 32 and 33 are connected to the positive and negative inputs respectively of ramp generator 34. The output of 34 is connected to charge capacitor C. The voltage of C is compared by voltage discriminator 35 with the horizontal drive voltage from 15. The output from 35, indicating that the voltage on C is less than the horizontal drive voltage, is connected to an input of And 36 which also receives the Right signal from control
20. The output of 36 is connected to an input of 32. And 37, which has its output connected to an input of 33, has an input connected to receive the Left signal from 20 and an input from 35 which indicates that the voltage of C is greater than the horizont...