US4387394A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sensing focus of a color kinescope
Assignee: RCA Corp
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Filing: 1980-12-31
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Granted: 1983-06-07
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Expires: 2000-12-31
Abstract
Abstract An apparatus for sensing electron beam focus on the display screen of a kinescope comprises a photodiode adapted to detect the light output from an area on the kinescope display screen. A signal having a frequency equal to the scanned excitation rate of the individual screen phosphor element areas being excited by a deflected electron beam is developed from the photodiode output. The variation in the amplitude of this signal is an indication of electron beam focus condition.
Inventors
- 👤 Jerry P. Powell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:55
CPC Classifications
H; H04; H04N; H04N17/00; H04N17/04; H01; H01J; H01J9/00; H01J9/44
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
103 words
Apparatus for sensing electron beam focus for use with a kinescope having an electron gun assembly for producing an electron beam, said beam impinging on a display screen to excite a plurality of phosphor elements, said sensing apparatus comprising: means for deflecting said beam across said screen to provide the excitation of said phosphor elements in a predetermined order; means for detecting an output from said phosphor elements representative of the rate at which said beam excites said phosphor elements; and means responsive to said detected output for deriving a signal component the variation of which is indicative of electron beam focus condition.
Claim 2
Dependent Claim
103 words
Apparatus for sensing electron beam focus for use with a kinescope having an electron gun assembly for producing an electron beam, said beam impinging on a display screen to excite a plurality of phosphor elements, said sensing apparatus comprising: means for deflecting said beam across said screen to provide the excitation of said phosphor elements in a predetermined order; means for detecting an output from said phosphor elements representative of the rate at which said beam excites said phosphor elements; and means responsive to said detected output for deriving a signal component the variation of which is indicative of electron beam focus condition.
Claim 3
Dependent Claim
13 words
The arrangement defined in claim 1, wherein said detecting means comprises a photodiode.
Claim 4
Dependent Claim
15 words
The arrangement defined in claim 1, wherein said deriving means comprises a high pass filter.
Claim 5
Dependent Claim
20 words
The arrangement defined in claim 3, wherein said high pass filter exhibits a cut off frequency of approximately 7 MHz.
Claim 6
Dependent Claim
22 words
The arrangement defined in claim 1, wherein said signal component exhibits an increase in amplitude as said electron beam focus condition improves.
Claim 7
Dependent Claim
24 words
The arrangement defined in claim 1, wherein said phosphor elements exhibit a particular rate of excitation when said beam is deflected across said screen.
Claim 8
Dependent Claim
21 words
The arrangement defined in claim 6, wherein said phosphor element excitation rate is substantially independent of said electron beam focus condition.
Claim 9
Dependent Claim
22 words
The arrangement defined in claim 6, wherein said signal component exhibits a frequency substantially equal to said phosphor element rate of excitation.
Claim 10
Dependent Claim
130 words
Apparatus for sensing electron beam focus for use with a kinescope having an electron gun assembly for producing an electron beam, said beam impinging on a display screen to excite a plurality of phosphor elements, and incorporating means, coupled to said kinescope, for adjusting the focus of said electron beam, said sensing apparatus comprising: means for deflecting said beam across said screen to provide the excitation of said phosphor elements in a predetermined order; means for detecting an output from said phosphor elements representative of the rate at which said beam excites said phosphor elements; means responsive to said detected output for deriving a signal component the variation of which is indicative of electron beam focus condition; and means responsive to said signal component, for controlling said focus adjusting means.
Claim 11
Dependent Claim
130 words
Apparatus for sensing electron beam focus for use with a kinescope having an electron gun assembly for producing an electron beam, said beam impinging on a display screen to excite a plurality of phosphor elements, and incorporating means, coupled to said kinescope, for adjusting the focus of said electron beam, said sensing apparatus comprising: means for deflecting said beam across said screen to provide the excitation of said phosphor elements in a predetermined order; means for detecting an output from said phosphor elements representative of the rate at which said beam excites said phosphor elements; means responsive to said detected output for deriving a signal component the variation of which is indicative of electron beam focus condition; and means responsive to said signal component, for controlling said focus adjusting means.
Claim 12
Dependent Claim
14 words
The arrangement defined in claim 9, wherein said focus adjusting means comprises a potentiometer.
Claim 13
Dependent Claim
13 words
The arrangement defined in claim 9, wherein said controlling means comprises a servomotor.
Claim 14
Dependent Claim
48 words
The arrangement defined in claim 1, wherein said derived signal component includes a signal component the amplitude of which is indicative of the brightness of said excited phosphor elements, and wherein said deriving means incorporates means for removing said brightness indicative signal component from said derived signal component.
Claim 15
Dependent Claim
22 words
The arrangement defined in claim 1, wherein said deriving means incorporates a low pass filter for removing said brightness indicative signal component.
Claim 16
Independent Claim
99 words
A method for sensing electron beam focus for use with a kinescope having an electron gun assembly for producing an electron beam, said beam impinging on a display screen to excite a plurality of phosphor elements, comprising the steps of: scanning said beam across said screen to excite said phosphor elements in a predetermined order at a predetermined rate; detecting an output from said phosphor elements in response to said phosphor element excitation related to said predetermined rate; and developing a signal component responsive to said detected output, indicative of the degree of sharpness of the electron beam focus.
Claim 17
Independent Claim
99 words
A method for sensing electron beam focus for use with a kinescope having an electron gun assembly for producing an electron beam, said beam impinging on a display screen to excite a plurality of phosphor elements, comprising the steps of: scanning said beam across said screen to excite said phosphor elements in a predetermined order at a predetermined rate; detecting an output from said phosphor elements in response to said phosphor element excitation related to said predetermined rate; and developing a signal component responsive to said detected output, indicative of the degree of sharpness of the electron beam focus.
Claim 18
Independent Claim
132 words
A method for adjusting focus of an electron beam for use with a kinescope having an electron gun assembly for producing an electron beam, said beam impinging on a display screen to excite a plurality of phosphor elements, and incorporating means, coupled to said kinescope, for adjusting the focus of said electron beam, comprising the steps of: scanning said beam across said screen to excite said phosphor elements in a predetermined order; detecting an output from said phosphor elements representative of the rate at which said beam excites said phosphor elements; developing a signal component responsive to said detected output the variations of which are indicative of electron beam focus condition; and varying said focus adjusting means until said signal component variations indicate the occurrence of the desired electron beam focus condition.
Claim 19
Independent Claim
132 words
A method for adjusting focus of an electron beam for use with a kinescope having an electron gun assembly for producing an electron beam, said beam impinging on a display screen to excite a plurality of phosphor elements, and incorporating means, coupled to said kinescope, for adjusting the focus of said electron beam, comprising the steps of: scanning said beam across said screen to excite said phosphor elements in a predetermined order; detecting an output from said phosphor elements representative of the rate at which said beam excites said phosphor elements; developing a signal component responsive to said detected output the variations of which are indicative of electron beam focus condition; and varying said focus adjusting means until said signal component variations indicate the occurrence of the desired electron beam focus condition.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-06 | 1986-12-06 | 1987-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-06 | 1990-12-06 | 1991-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-06 | 1994-12-06 | 1995-06-07 | $7700.00 | Window Closed / Lapsed |