US3820155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Television receiver service adjustment system
Assignee: RCA Licensing Corp
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Filing: 1973-05-08
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Granted: 1974-06-25
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Expires: 1993-05-08
Abstract
Abstract Apparatus for providing auxiliary reference signals useful in setting up the cutoff points of each of a plurality of electron guns in a color kinescope or picture tube. The reference signals are substituted in place of luminance signals by means of a service switch having at least ''''normal'''' and ''''service'''' positions. In the service or set-up mode of operation, with the reference signals applied and vertical scan collapsed, the screen grid to cathode voltage of each of the guns is adjusted to produce a dim white line on the kinescope. The polarity and amplitude of the reference signals is selected so that, upon return of the service switch to normal position and reconnection of the luminance signal channel, the conduction of each of the electron guns is decreased. As a result, the cutoff points of the guns correspond closely to luminance signal black level.
Inventors
- 👤 D Neal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:10
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/73; H04N9/12; H04N9/16; H04N9/18; H04N9/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
206 words
In a color television image reproducing apparatus including a source of luminance signals and a color kinescope having a plurality of electron guns, each gun having a separate cathode, a service adjustment system comprising: amplifying means for coupling at least said luminance signals to said cathodes during a normal mode of operation of said apparatus, means associated with each of said electron guns for varying bias voltages applied thereto to control cutoff of electron beam current in each of said guns, a source of reference signals, said signals being of a polarity to cause increased conduction of said electron guns upon coupling of said source to said amplifying means, and switching means for coupling said source of luminance signals to said amplifying means in a normal mode of operation and for coupling said source of reference signals to said amplifying means in a service mode of operation, said reference signals being of such amplitude that said bias voltage varying means may be adjusted during said service mode to produce conduction in said guns and a resulting visible pattern on said kinescope and, upon transfer of said switching means to said normal mode of operation, conduction in said guns and the intensity of said pattern are diminished.
Claim 2
Dependent Claim
206 words
In a color television image reproducing apparatus including a source of luminance signals and a color kinescope having a plurality of electron guns, each gun having a separate cathode, a service adjustment system comprising: amplifying means for coupling at least said luminance signals to said cathodes during a normal mode of operation of said apparatus, means associated with each of said electron guns for varying bias voltages applied thereto to control cutoff of electron beam current in each of said guns, a source of reference signals, said signals being of a polarity to cause increased conduction of said electron guns upon coupling of said source to said amplifying means, and switching means for coupling said source of luminance signals to said amplifying means in a normal mode of operation and for coupling said source of reference signals to said amplifying means in a service mode of operation, said reference signals being of such amplitude that said bias voltage varying means may be adjusted during said service mode to produce conduction in said guns and a resulting visible pattern on said kinescope and, upon transfer of said switching means to said normal mode of operation, conduction in said guns and the intensity of said pattern are diminished.
Claim 3
Dependent Claim
66 words
A service adjustment system according to claim 1 wherein: said means for varying bias voltages applied to said electron guns is adjustable, upon coupling of said source of reference signals to said amplifying means in the service mode of operation, to vary conduction of each of said electron guns between at least a cutoff condition and Conduction sufficient to produce a visible pattern on said kinescope.
Claim 4
Dependent Claim
39 words
A service adjustment system according to claim 2 wherein: the amplitude of said reference signals is such that, upon transfer of said switching means to said normal mode of operation, conduction in said guns is reduced substantially to cutoff.
Claim 5
Dependent Claim
49 words
A service adjustment system according to claim 3 wherein: said switching means is further arranged for disabling operation of one of the vertical and horizontal beam deflection systems associated with said kinescope such that said visible pattern is in the form of a relatively narrow line on said kinescope.
Claim 6
Dependent Claim
36 words
A service adjustment system according to claim 3 wherein: said means associated with each of said electron guns is arranged for varying bias voltages applied between the screen grid and cathode of each of said guns.
Claim 7
Dependent Claim
114 words
A service adjustment system according to claim 1 wherein: said amplifying means comprises a plurality of amplifier circuits equal in number to said cathodes, each amplifier circuit having at least an output electrode direct current coupled to one of said cathodes, a first input electrode for application thereto of luminance signals and a clamping circuit coupled to said output electrode for substantially maintaining a predetermined quiescent direct voltage at said output electrode in said normal mode of operation, and said source of reference signals is arranged to provide signals to said clamping circuit in said service mode to modify said quiescent direct voltage in a direction to increase conduction of each of said guns.
Claim 8
Dependent Claim
21 words
A service adjustment system according to claim 6 wherein: said reference signals include pulses occurring during each horizontal deflection retrace interval.
Claim 9
Dependent Claim
49 words
A service adjustment system according to claim 7 wherein: said switching means is further arranged for disabling operation of one of the vertical and horizontal beam deflection systems associated with said kinescope such that said visible pattern is in the form of a relatively narrow line on said kinescope.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |