US5508739A
Expired / Lapsed
US
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White-balance adjusting apparatus and a method thereof for a video camera
Assignee: LG Electronics Inc
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Filing: 1994-12-21
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Granted: 1996-04-16
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Expires: 2014-12-21
Abstract
Abstract An improved white-balance adjusting apparatus and a method thereof for a video camera capable of automatically varying a white-balance trace region in accordance with a change in color temperatures of a light source and of performing an automatic white-balance adjusting operation. The apparatus includes a dividing circuit for integrating a first primary color signal for a predetermined time and for computing an integration value ratio of a second primary color signal in response to the integration value ratio of the first primary color signal; a color temperature detection circuit for detecting a color temperature change of a light source from the integration value ratio; and a gain computation circuit, when an integration value ratio is within a range of at least one white-balance trace region, for selecting a white-balance trace region in accordance with a detected color temperature change and for computing a gain of a primary color in accordance with the integration value ratio in a range of a selected white-balance trace region.
Inventors
- 👤 Sang W. Suh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:59
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/80; H04N23/84; H04N23/88; H04N23/60
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
156 words
A white-balance adjusting apparatus for a video camera, comprising: divider means for integrating a plurality of primary color signals for a first predetermined time to output a plurality of integration signals and for computing a plurality of integration value ratios from the integration signals, said divider means including an integrator which integrates one of the primary color signals for the first predetermined time and a second predetermined time immediately following the first predetermined time; color temperature detection means for generating first and second detection signals from the integration value ratios computed by said divider means and detecting a color temperature change of a light source according to the first and second detection signals; and gain computation means for selecting a white-balance trace region in accordance with the color temperature change detected by said color temperature detection means and computing gains of the primary color signals in accordance with a range of the selected white-balance trace region.
Claim 2
Dependent Claim
156 words
A white-balance adjusting apparatus for a video camera, comprising: divider means for integrating a plurality of primary color signals for a first predetermined time to output a plurality of integration signals and for computing a plurality of integration value ratios from the integration signals, said divider means including an integrator which integrates one of the primary color signals for the first predetermined time and a second predetermined time immediately following the first predetermined time; color temperature detection means for generating first and second detection signals from the integration value ratios computed by said divider means and detecting a color temperature change of a light source according to the first and second detection signals; and gain computation means for selecting a white-balance trace region in accordance with the color temperature change detected by said color temperature detection means and computing gains of the primary color signals in accordance with a range of the selected white-balance trace region.
Claim 3
Dependent Claim
56 words
The apparatus of claim 1, wherein said white-balance trace region includes a first region being selected when a color temperature of the light source moves from a high region to a low region and a second region being selected when the color temperature of the light source moves from the low region to the high region.
Claim 4
Dependent Claim
46 words
The apparatus of claim 1, wherein said color temperature detection means includes a plurality of delay means for delaying the integration value ratios for the first predetermined time and a plurality of comparing means for comparing the delayed integration value ratios with current integration value ratios.
Claim 5
Dependent Claim
20 words
The apparatus of claim 1, wherein each of said first and second said predetermined times is a one field period.
Claim 6
Independent Claim
163 words
A method of white-balance adjusting for a video camera, comprising the steps of: generating a plurality of first and second integration signals, said first integration signal representing integration of a primary color signal for a first predetermined time and said second integration signal representing integration of the primary color signal for a second predetermined time immediately following the first predetermined time, said integrations being carried out by a same integrator; computing a plurality of integration value ratios from the integration signals; generating first and second detection signals by comparing the integration value ratios; detecting whether or not each of the computed integration value ratios falls within a predetermined range of a plurality of white-balance trace regions; selecting a corresponding white-balance trace region based on the first and second detection signals when each of the computed integration value ratios is within the range of the white-balance trace regions; and adjusting a gain of the primary color signal according to the selected white-balance trace region.
Claim 7
Independent Claim
163 words
A method of white-balance adjusting for a video camera, comprising the steps of: generating a plurality of first and second integration signals, said first integration signal representing integration of a primary color signal for a first predetermined time and said second integration signal representing integration of the primary color signal for a second predetermined time immediately following the first predetermined time, said integrations being carried out by a same integrator; computing a plurality of integration value ratios from the integration signals; generating first and second detection signals by comparing the integration value ratios; detecting whether or not each of the computed integration value ratios falls within a predetermined range of a plurality of white-balance trace regions; selecting a corresponding white-balance trace region based on the first and second detection signals when each of the computed integration value ratios is within the range of the white-balance trace regions; and adjusting a gain of the primary color signal according to the selected white-balance trace region.
Claim 8
Dependent Claim
33 words
The method of claim 5, further comprising the step of comparing the integration value ratio of a previous field which is outputted after a third predetermined time with a current integration value ratio.
Claim 9
Dependent Claim
19 words
The method of claim 6, wherein each of said first and second predetermined times is a one field period.
Claim 10
Dependent Claim
55 words
The method of claim 6, wherein said trace regions include a first region being selected when a color temperature of a light source moves from a low region to a high region and a second region being selected when the color temperature of the light source moves from the high region to the low region.
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) | 1999-04-16 | 1999-10-16 | 2000-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-16 | 2003-10-16 | 2004-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-16 | 2007-10-16 | 2008-04-16 | $7700.00 | Window Closed / Lapsed |