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US4458178A Expired / Lapsed US ⏱️ 0.0 years remaining

Logic controlled degaussing system

Assignee: Motorola Solutions Inc
•
Filing: 1982-09-29
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Granted: 1984-07-03
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Expires: 2002-09-29
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Abstract

Abstract A CRT in a CRT device is degaussed following a timed period of device inactivity and while the screen of the CRT is darkened, as well as at device turn-on or at manual activation. The screen stays darkened until data is inputted, and degaussing reoccurs during each subsequent timed period of inactivity.

Inventors

  • 👤 David L. Tenney
  • 👤 James Krause
  • 👤 John R. Welk

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-10 00:51
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/16; H04N9/29

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 56 words
A logic controlled degaussing system for a CRT device and comprising: detector means for detecting signal activity in the device; timing means coupled to the detector means for providing an output signal in response to a predetermined period of inactivity; and a degaussing circuit for degaussing the CRT in response to the timing means output signal.
Claim 2
Dependent Claim 56 words
A logic controlled degaussing system for a CRT device and comprising: detector means for detecting signal activity in the device; timing means coupled to the detector means for providing an output signal in response to a predetermined period of inactivity; and a degaussing circuit for degaussing the CRT in response to the timing means output signal.
Claim 3
Dependent Claim 34 words
A logic controlled degaussing system according to claim 1 and wherein the timing means provides an output signal in response to each predetermined period of activity immediately subsequent to each first said predetermined period.
Claim 4
Dependent Claim 49 words
A logic controlled degaussing system according to claim 1 and further including a dimming circuit for reducing substantially the CRT brightness of at least a portion of the CRT screen in response to the timing means output signal, the degaussing circuit being enabled while the CRT brightness is reduced.
Claim 5
Dependent Claim 32 words
A logic controlled degaussing system according to claim 3 and wherein the CRT device includes a keyboard for inputting data and wherein the dimming circuit is disabled by activation of the keyboard.
Claim 6
Dependent Claim 35 words
A logic controlled degaussing system according to claim 1 and wherein the degaussing circuit is adapted to function without powering down the CRT device and to be disabled at the end of each degaussing cycle.
Claim 7
Dependent Claim 21 words
A logic controlled degaussing system according to claim 1 and further including means for enabling the degaussing circuit at device turn-on.
Claim 8
Dependent Claim 18 words
A logic controlled degaussing system according to claim 1 and further means for manually enabling the degaussing circuit.
Claim 9
Dependent Claim 23 words
A logic controlled degaussing system according to claim 3 and further including means for manually enabling the dimming circuit and the degaussing circuit.
Claim 10
Independent Claim 43 words
A method of degaussing a CRT in a CRT device and comprising the steps of: detecting signal activity in the CRT device; providing an output signal in response to a predetermined period of inactivity; degaussing the CRT in response to the output signal.
Claim 11
Independent Claim 43 words
A method of degaussing a CRT in a CRT device and comprising the steps of: detecting signal activity in the CRT device; providing an output signal in response to a predetermined period of inactivity; degaussing the CRT in response to the output signal.
Claim 12
Dependent Claim 41 words
The method of claim 9 and further including the step of reducing substantially the brightness of at least a portion of the CRT screen in response to the output signal and wherein the degaussing step occurs while the brightness is reduced.
Claim 13
Dependent Claim 20 words
The method of claim 10 and wherein the previous steps are repeated as long as inactivity in the device continues.

References Cited (Backward Citations)

US4262232A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-07-03 1988-01-02 1988-07-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-07-03 1992-01-02 1992-07-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-07-03 1996-01-02 1996-07-03 $7700.00 Window Closed / Lapsed

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