US6452582B1
Expired / Lapsed
US
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Method and apparatus for refreshing a liquid crystal display
Assignee: Garmin Corp Taiwan
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Filing: 1999-12-01
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Granted: 2002-09-17
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Expires: 2019-12-01
Abstract
Abstract A method and apparatus for refreshing a passive liquid crystal display. A device implements a liquid crystal display, having a liquid crystal module, a backlight, a processor, and controllers. The processor establishes a first frequency for the backlight to provide dimming ratios greater than 20 to 1. The processor establishes a second frequency for refreshing the LCD module such that the ratio of the display refresh frequency to backlight frequency is 6.5. The multiplicative and fractional factor reduces display aliases and beat frequency artifacts created by the differences in the two frequencies.
Inventors
- 👤 Walter Rolston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:03
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3406; G09G2320/00; G09G2320/06; G09G2320/0626; G09G2320/064; G09G2330/00; G09G2330/06
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
81 words
A method of displaying data on a display comprised of liquid crystals, said method comprising: providing a backlight having a backlight frequency; refreshing liquid crystals of a display at a refresh rate; setting said refresh rate to be greater than said backlight frequency, wherein at least one of said refresh rate and backlight frequency is greater than 60 Hz; and selecting a ratio between said backlight frequency and said refresh rate of said liquid crystals, wherein said ratio includes a fraction.
Claim 2
Independent Claim
81 words
A method of displaying data on a display comprised of liquid crystals, said method comprising: providing a backlight having a backlight frequency; refreshing liquid crystals of a display at a refresh rate; setting said refresh rate to be greater than said backlight frequency, wherein at least one of said refresh rate and backlight frequency is greater than 60 Hz; and selecting a ratio between said backlight frequency and said refresh rate of said liquid crystals, wherein said ratio includes a fraction.
Claim 3
Dependent Claim
24 words
The method as set forth in claim 1 , wherein said refresh rate is between 5.5 and 7.5 times greater than said backlight frequency.
Claim 4
Dependent Claim
22 words
The method as set forth in claim 1 , wherein said refresh rate is approximately 6.5 times greater than said backlight frequency.
Claim 5
Dependent Claim
32 words
The method as set forth in claim 1 , wherein said backlight has an associated dimming ratio, said method further comprising setting said dimming ratio to be greater than 20 to 1.
Claim 6
Dependent Claim
19 words
The method as set forth in claim 4 , wherein said dimming ratio is greater than 100 to 1.
Claim 7
Dependent Claim
19 words
The method as set forth in claim 4 , wherein said dimming ratio is greater than 300 to 1.
Claim 8
Independent Claim
97 words
A method of displaying data on a display comprised of liquid crystals, said method comprising: providing a backlight having a backlight frequency; refreshing liquid crystals of a display at a refresh rate; setting said refresh rate to be greater than said backlight frequency, wherein at least one of said refresh rate and backlight frequency is greater than 60 Hz; setting a ratio between said refresh rate and said backlight frequency in order to set a fraction of said ratio to be one-half; and setting said refresh rate and said backlight frequency to each be above 60 Hz.
Claim 9
Independent Claim
97 words
A method of displaying data on a display comprised of liquid crystals, said method comprising: providing a backlight having a backlight frequency; refreshing liquid crystals of a display at a refresh rate; setting said refresh rate to be greater than said backlight frequency, wherein at least one of said refresh rate and backlight frequency is greater than 60 Hz; setting a ratio between said refresh rate and said backlight frequency in order to set a fraction of said ratio to be one-half; and setting said refresh rate and said backlight frequency to each be above 60 Hz.
Claim 10
Dependent Claim
19 words
The method as set forth in claim 7 , wherein said refresh rate is greater than said backlight frequency.
Claim 11
Dependent Claim
17 words
The method as set forth in claim 7 , wherein said ratio is between 5.5 and 7.5.
Claim 12
Dependent Claim
32 words
The method as set forth in claim 7 , wherein said backlight has an associated dimming ratio, said method further comprising establishing said dimming ratio to be greater than 20 to 1.
Claim 13
Independent Claim
58 words
A method of displaying data on a passive display comprising liquid crystals, said method comprising: providing a backlight having a backlight frequency; refreshing liquid crystals of a display at a refresh rate, and setting said refresh rate greater than said backlight frequency, wherein at least one of said refresh rate and backlight frequency is greater than 60 Hz.
Claim 14
Independent Claim
58 words
A method of displaying data on a passive display comprising liquid crystals, said method comprising: providing a backlight having a backlight frequency; refreshing liquid crystals of a display at a refresh rate, and setting said refresh rate greater than said backlight frequency, wherein at least one of said refresh rate and backlight frequency is greater than 60 Hz.
Claim 15
Dependent Claim
29 words
The method of claim 11 , further comprising: selecting a ratio between said backlight frequency and said refresh rate of said liquid crystals, wherein said ratio includes a fraction.
Claim 16
Dependent Claim
22 words
The method of claim 11 , further comprising: setting said refresh rate and said backlight frequency to each be above 60 Hz.
Claim 17
Dependent Claim
31 words
The method of claim 11 , further comprising: setting a ratio between said refresh rate and said backlight frequency in order to set a fraction of said ratio to be one-half.
Claim 18
Independent Claim
85 words
A device comprising: a passive display comprised of a plurality of liquid crystals; a backlight for illuminating said passive display at a backlight frequency; a controller for refreshing said liquid crystals of said passive display at a refresh frequency, wherein at least one of said refresh rate and backlight frequency is greater than 60 Hz, said controller setting a ratio between said backlight frequency and said refresh frequency to be a fraction, said controller setting said refresh frequency to be greater than said backlight frequency.
Claim 19
Independent Claim
85 words
A device comprising: a passive display comprised of a plurality of liquid crystals; a backlight for illuminating said passive display at a backlight frequency; a controller for refreshing said liquid crystals of said passive display at a refresh frequency, wherein at least one of said refresh rate and backlight frequency is greater than 60 Hz, said controller setting a ratio between said backlight frequency and said refresh frequency to be a fraction, said controller setting said refresh frequency to be greater than said backlight frequency.
Claim 20
Dependent Claim
21 words
The device as set forth in claim 15 , wherein said backlight is comprised of a plurality of light emitting diodes.
Claim 21
Dependent Claim
19 words
The device as set forth in claim 15 , wherein said backlight is comprised of a cathode fluorescent tube.
Claim 22
Dependent Claim
18 words
The device as set forth in claim 15 , wherein said backlight frequency is greater than 60 Hz.
Claim 23
Dependent Claim
17 words
The device as set forth in claim 15 , wherein said backlight frequency is approximately 70 Hz.
Claim 24
Dependent Claim
20 words
The device as set forth in claim 15 , wherein said refresh frequency to said backlight frequency ratio is 6.5.
Claim 25
Dependent Claim
14 words
The device as set forth in claim 15 , wherein said fraction is one-half.
Claim 26
Dependent Claim
24 words
The device as set forth in claim 15 , wherein said controller sets said fraction to one-half in order to reduce beat frequency artifacts.
Claim 27
Dependent Claim
16 words
The device as set forth in claim 15 , wherein said device is a navigation device.
Claim 28
Dependent Claim
17 words
The device as set forth in claim 15 , wherein said passive display is a color display.
Claim 29
Dependent Claim
23 words
The device as set forth in claim 15 , wherein said controller sets said refresh frequency to minimize artifacts on said passive display.
Claim 30
Dependent Claim
22 words
The device as set forth in claim 15 , wherein said controller sets said ratio to minimize artifacts on said passive display.
Claim 31
Dependent Claim
24 words
The device as set forth in claim 15 , wherein said controller sets said fraction of said ratio to minimize artifacts on said display.
Claim 32
Independent Claim
84 words
A device comprising: a passive display comprised of a plurality of liquid crystals; a backlight for illuminating said passive display at a backlight frequency; a controller for refreshing said liquid crystals of said passive display at a refresh frequency, said controller setting said refresh frequency to be greater than said backlight frequency said controller setting a ratio between said backlight frequency and said refresh frequency to be one-half, said controller setting said refresh frequency and said backlight frequency to be greater than 60 Hz.
Claim 33
Independent Claim
84 words
A device comprising: a passive display comprised of a plurality of liquid crystals; a backlight for illuminating said passive display at a backlight frequency; a controller for refreshing said liquid crystals of said passive display at a refresh frequency, said controller setting said refresh frequency to be greater than said backlight frequency said controller setting a ratio between said backlight frequency and said refresh frequency to be one-half, said controller setting said refresh frequency and said backlight frequency to be greater than 60 Hz.
Claim 34
Dependent Claim
17 words
The device as set forth in claim 28 , wherein said backlight frequency is approximately 70 Hz.
Claim 35
Dependent Claim
20 words
The device as set forth in claim 28 , wherein said refresh frequency to said backlight frequency ratio is 6.5.
Claim 36
Dependent Claim
17 words
The device as set forth in claim 28 , wherein said passive display is a DSTN display.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2005-09-16 | 2006-03-18 | 2006-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-09-16 | 2010-03-18 | 2010-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-09-16 | 2014-03-18 | 2014-09-17 | $7700.00 | Window Closed / Lapsed |