US4731652A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shading correction signal generating device for a television camera apparatus
Assignee: Toshiba Corp
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Filing: 1987-03-25
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Granted: 1988-03-15
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Expires: 2007-03-25
Abstract
Abstract A shading correction wave generating unit generates a predetermined shading correction waveform signal including AC signal components on the basis of a scanning drive signal with at least one of horizontal or vertical scanning frequencies for a TV screen. An area-designating signal generating unit generates an area-designating signal to designate a specific area on the TV screen on the basis of said scanning drive signal. A potential clamping unit receives the predetermined shading correction waveform signal including AC signal components and the area-designating signal, and clamps the predetermined shading correction waveform including AC components to a specific potential in the specific area designated by the area-designating signal. An output unit produces a shading correction signal which is the predetermined shading correction waveform signal including AC components as clamped to the specific potential in the specific area by the potential clamping unit.
Inventors
- 👤 Junichi Yamanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:02
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/80; H04N23/81
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
157 words
A shading correction signal generating device for a television camera apparatus, said device comprising: shading correction wave generating means for generating a predetermined shading correction waveform signal including AC signal components on the basis of a scanning drive signal with at least one of horizontal or vertical scanning frequencies for a TV screen; area-designating signal generating means for generating an area-designating signal to designate a specific area on the TV screen on the basis of said scanning drive signal; potential clamping means for receiving said predetermined shading correction waveform signal including AC signal components and said area-designating signal, and for clamping said predetermined shading correction waveform including AC components to a specific potential in said specific area designated by said area-designating signal; and output means for producing a shading correction signal which is said predetermined shading correction waveform signal including AC components as clamped to the specific potential in the specific area by said potential clamping means.
Claim 2
Dependent Claim
157 words
A shading correction signal generating device for a television camera apparatus, said device comprising: shading correction wave generating means for generating a predetermined shading correction waveform signal including AC signal components on the basis of a scanning drive signal with at least one of horizontal or vertical scanning frequencies for a TV screen; area-designating signal generating means for generating an area-designating signal to designate a specific area on the TV screen on the basis of said scanning drive signal; potential clamping means for receiving said predetermined shading correction waveform signal including AC signal components and said area-designating signal, and for clamping said predetermined shading correction waveform including AC components to a specific potential in said specific area designated by said area-designating signal; and output means for producing a shading correction signal which is said predetermined shading correction waveform signal including AC components as clamped to the specific potential in the specific area by said potential clamping means.
Claim 3
Dependent Claim
25 words
A shading correction signal generating device according to claim 1, wherein said specific area is located approximately at the center area on the television screen.
Claim 4
Dependent Claim
18 words
A shading correction signal generating device according to claim 2, wherein said predetermined potential is the reference potential.
Claim 5
Dependent Claim
30 words
A shading correction signal generating device according to claim 1, wherein said output means includes means for outputting said shading correction signal as said reference potential, during a blanking period.
Claim 6
Dependent Claim
81 words
A shading correction signal generating device according to claim 1, wherein said potential clamping means includes a first operational amplifier for receiving said predetermined shading correction waveform, outputting said shading correction signal, a sample/hold circuit for sampling and holding the output of said first operational amplifier by said area designating signal, and a second operational amplifier for comparing the output of said sample/hold circuit with reference potential, and for feeding back the result of the comparison to said first operational amplifier.
Claim 7
Dependent Claim
22 words
A shading correction signal generating device according to claim 1, wherein said shading correction waveform is a waveform for superposing shading correction.
Claim 8
Dependent Claim
22 words
A shading correction signal generating device according to claim 1, wherein said shading correction waveform is a waveform for modulation shading correction.
Claim 9
Dependent Claim
27 words
A shading correction signal generating device according to claim 1, wherein said shading correction waveform includes the waveforms for superposing shading correction and for modulation shading correction.
Claim 10
Dependent Claim
19 words
A shading correction signal generating device according to claim 1, wherein said shading correction waveform includes a saw-tooth waveform.
Claim 11
Dependent Claim
19 words
A shading correction signal generating device according to claim 1, wherein said shading correction waveform includes a parabolic waveform.
Claim 12
Dependent Claim
33 words
A shading correction signal generating device according to claim 1, wherein said shading correction waveform generating means includes means for mixing a saw-tooth waveform and a parabolic waveform at a predetermined mixing ratio.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-15 | 1991-09-14 | 1992-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-15 | 1995-09-14 | 1996-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-15 | 1999-09-14 | 2000-03-15 | $7700.00 | Window Closed / Lapsed |