Patent US6943756B1 successfully refreshed from Google Patents.
US6943756B1
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Device for enhancing contrast in liquid crystal display projection system
Assignee: Samsung Electronics Co Ltd
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Filing: 2000-07-28
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Granted: 2005-09-13
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Expires: 2020-07-28
Abstract
Abstract A device for enhancing contrast for a liquid crystal display (LCD) projection system is provided. The contrast enhancing device includes an image driver supplying an image signal, a LCD panel for converting the input image signal into an optical image signal, and a contrast control portion positioned on the same optical axis as that of the LCD panel, for controlling an amount of scanned light according to the brightness of a corresponding image. Accordingly, the projection system adopting an image display device as a liquid crystal device provides a remarkably enhanced contrast enhancement effect. In particular, as the brightness of the total image is brighter, the contrast enhancement effect becomes larger.
Inventors
- 👤 Jong-Chul Choi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:42
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/312; H04N9/3126; H04N9/3179; H04N9/3182
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
71 words
A device for enhancing contrast for a liquid crystal display (LCD) projection system, the contrast enhancing device comprising: an image driver supplying an image signal; an LCD panel for converting the image signal into an optical image signal; and a contrast control portion positioned on the same optical axis as that of the LCD panel, for controlling the contrast of scanned light according to an average level of the image signal.
Claim 2
Independent Claim
71 words
A device for enhancing contrast for a liquid crystal display (LCD) projection system, the contrast enhancing device comprising: an image driver supplying an image signal; an LCD panel for converting the image signal into an optical image signal; and a contrast control portion positioned on the same optical axis as that of the LCD panel, for controlling the contrast of scanned light according to an average level of the image signal.
Claim 3
Dependent Claim
19 words
The contrast enhancing device of claim 1 , wherein said image driver comprises an auto brightness limiter (ABL) function.
Claim 4
Dependent Claim
59 words
The contrast enhancing device of claim 2 , wherein said contrast control portion comprises: a contrast control plate for controlling an amount of light scanned from said LCD panel; and a contrast controller for generating a contrast control signal for controlling the degree of the opening and closing of said contrast control plate according to an ABL control signal.
Claim 5
Dependent Claim
31 words
The contrast enhancing device of claim 3 , wherein said contrast controller applies the contrast control signal which is inversely proportional to the ABL control signal supplied from said image driver.
Claim 6
Dependent Claim
16 words
The contrast enhancing device of claim 3 , wherein said contrast control plate is an LCD.
Claim 7
Dependent Claim
37 words
The contrast enhancing device of claim 5 , wherein said contrast control plate controls the degree of the opening and closing of cells comprising the LCD according to the contrast control signal applied from said contrast controller.
Claim 8
Dependent Claim
75 words
The contrast enhancing device of claim 3 , wherein said contrast controller applies the contrast control signal for controlling said contrast control plate to be closed in correspondence to a difference value if the average level of the image signal is lower that a reference level, or controlling said contrast control plate to be opened in correspondence to a difference value if the average level of the image signal is higher than the reference level.
Claim 9
Dependent Claim
28 words
The projection system of claim 3 , wherein said contrast control plate is opened if an average level of the image signal is higher than a reference level.
Claim 10
Dependent Claim
50 words
The contrast enhancing device of claim 1 , further comprising a polarizing plate for selectively transmitting the light scanned from said LCD panel according to the polarization component of the light, wherein said contrast control portion is disposed on an optical path between said LCD panel and said polarizing plate.
Claim 11
Dependent Claim
76 words
A liquid crystal display projection system, the projection system comprising: an image driver supplying an image signal and a brightness control signal; a liquid crystal display panel for converting the image signal into an optical image signal; and a contrast controller that controls the contrast of the optical image signal according to the brightness of the image signal, wherein the contrast controller applies a contrast control signal that is inversely proportional to the brightness control signal.
Claim 12
Dependent Claim
76 words
A liquid crystal display projection system, the projection system comprising: an image driver supplying an image signal and a brightness control signal; a liquid crystal display panel for converting the image signal into an optical image signal; and a contrast controller that controls the contrast of the optical image signal according to the brightness of the image signal, wherein the contrast controller applies a contrast control signal that is inversely proportional to the brightness control signal.
Claim 13
Dependent Claim
51 words
The projection system of claim 10 , wherein said contrast controller comprises: a control plate for controlling the contrast of the optical image signal output from said liquid crystal display panel; and a controller for generating the contrast control signal for controlling said control plate according to the brightness control signal.
Claim 14
Dependent Claim
16 words
The projection system of claim 11 , wherein said control plate is a liquid crystal device.
Claim 15
Dependent Claim
23 words
The projection system of claim 12 , wherein said contrast control signal controls the opening and closing of cells comprising the control plate.
Claim 16
Dependent Claim
27 words
The projection system of claim 13 , wherein said control plate is closed if an average level of the image signal is lower than a reference level.
Claim 17
Dependent Claim
27 words
The projection system of claim 13 , wherein said control plate is opened if an average level of the image signal is higher than a reference level.
Claim 18
Dependent Claim
51 words
The projection system of claim 10 , further comprising a polarizing plate for selectively transmitting light output from said liquid crystal device panel according to a polarization component of the light, wherein said contrast controller is disposed on an optical path between said liquid crystal device panel and said polarizing plate.
Claim 19
Dependent Claim
98 words
A liquid crystal display projection system, the projection system comprising: an image driver supplying an image signal; a liquid crystal display panel for converting the image signal into an optical image signal; a contrast control portion that controls the contrast of the optical image signal according to an average level of the image signal; and a polarizing plate for selectively transmitting light output from said liquid crystal device panel according to a polarization component of the light wherein said contrast control portion is disposed on an optical path between said liquid crystal device panel and said polarizing plate.
Claim 20
Dependent Claim
98 words
A liquid crystal display projection system, the projection system comprising: an image driver supplying an image signal; a liquid crystal display panel for converting the image signal into an optical image signal; a contrast control portion that controls the contrast of the optical image signal according to an average level of the image signal; and a polarizing plate for selectively transmitting light output from said liquid crystal device panel according to a polarization component of the light wherein said contrast control portion is disposed on an optical path between said liquid crystal device panel and said polarizing plate.
Claim 21
Dependent Claim
17 words
The projection system of claim 17 , wherein said image driver comprises an auto brightness limiter function.
Claim 22
Dependent Claim
61 words
The projection system of claim 18 , wherein said contrast control portion comprises: a contrast control plate for controlling the contrast of the optical image signal output from said liquid crystal display panel; and a contrast controller for generating a contrast control signal to control said contrast control plate according to a control signal output by the auto brightness limiter function.
Claim 23
Dependent Claim
26 words
The projection system of claim 19 , wherein said contrast control signal is inversely proportional to the control signal output by the auto brightness limiter function.
Claim 24
Dependent Claim
24 words
The projection system of claim 19 , wherein said contrast control signal controls the opening and closing of cells comprising the contrast control plate.
References Cited (Backward Citations)
US3724938A
Cited
US4635051A
Cited
JPS6254226A
Cited
JPS63298221A
Cited
US5181117A
Cited
US5048931A
Cited
JPH04199123A
Cited
US5231496A
Cited
JPH05188345A
Cited
US5303054A
Cited
US5634704A
Cited
JPH0715692A
Cited
JPH07168147A
Cited
US5597223A
Cited
KR0163077B1
Cited
US5622418A
Cited
US5889614A
Cited
US5952992A
Cited
US5801792A
Cited
JPH1073797A
Cited
US6243152B1
Cited
US6327093B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2008-09-12 | 2009-03-14 | 2009-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2012-09-12 | 2013-03-14 | 2013-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2016-09-12 | 2017-03-14 | 2017-09-13 | $7700.00 | Window Closed / Lapsed |