Patent US6674484B1 successfully refreshed from Google Patents.
Patent US6429839B1 successfully refreshed from Google Patents.
← Back to Patent Explorer
US6429839B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid crystal display apparatus and electronic device for providing control signal to liquid crystal display apparatus

Assignee: Sharp Corp
•
Filing: 1999-12-23
•
Granted: 2002-08-06
•
Expires: 2019-12-23
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A liquid crystal display apparatus includes a liquid crystal display device; a light source for illuminating the liquid crystal display device; a LCD device driving circuit for providing a driving voltage to the liquid crystal display device based on a display data signal and a plurality of liquid crystal driving signals including a display data latch signal; a dividing circuit for dividing a frequency of the display data latch signal by a factor of N so as to obtain a period which is N times as large as that of the display data latch signal, where N is an integer greater than zero; a duty control circuit for changing an ON duty ratio of the frequency-divided signal by using the frequency-divided signal as a reference frequency; and a light source driving circuit for turning the light source ON/OFF based on a signal from the duty control circuit having the ON duty ratio set in the duty control circuit, wherein, where a driving duty is (1/D), and a remainder of D divided by the integer N is A, each of the integer N and the value D is set to an integer greater than zero which satisfies the following expression:

Inventors

  • 👤 Atsushi Sakamoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 16:38
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3406; G09G2320/00; G09G2320/02; G09G2320/0247; G09G2320/04; G09G2320/041; G09G2320/043; G09G2320/06; G09G2320/0626; G09G2320/064

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 203 words
A liquid crystal display apparatus, comprising: a liquid crystal display device; a light source for illuminating the liquid crystal display device; a LCD device driving circuit for providing a driving voltage to the liquid crystal display device based on a display data signal and a plurality of liquid crystal driving signals including a display data latch signal; a dividing circuit for dividing a frequency of the display data latch signal by a factor of N so as to obtain a period which is N times as large as that of the display data latch signal, where N is an integer greater than zero; a duty control circuit for changing an ON duty ratio of the frequency-divided signal by using the frequency-divided signal as a reference frequency; and a light source driving circuit for turning the light source ON/OFF based on a signal from the duty control circuit having the ON duty ratio set in the duty control circuit, wherein where a driving duty ratio is (1/D), and a remainder of D divided by the integer N is A, each of the integer N and the value D is set to an integer greater than zero which satisfies the following expression: −1≦{( N/A )−2}≦1.
Claim 2
Dependent Claim 203 words
A liquid crystal display apparatus, comprising: a liquid crystal display device; a light source for illuminating the liquid crystal display device; a LCD device driving circuit for providing a driving voltage to the liquid crystal display device based on a display data signal and a plurality of liquid crystal driving signals including a display data latch signal; a dividing circuit for dividing a frequency of the display data latch signal by a factor of N so as to obtain a period which is N times as large as that of the display data latch signal, where N is an integer greater than zero; a duty control circuit for changing an ON duty ratio of the frequency-divided signal by using the frequency-divided signal as a reference frequency; and a light source driving circuit for turning the light source ON/OFF based on a signal from the duty control circuit having the ON duty ratio set in the duty control circuit, wherein where a driving duty ratio is (1/D), and a remainder of D divided by the integer N is A, each of the integer N and the value D is set to an integer greater than zero which satisfies the following expression: −1≦{( N/A )−2}≦1.
Claim 3
Dependent Claim 208 words
A liquid crystal display apparatus, comprising: a liquid crystal display device; a light source for illuminating the liquid crystal display device: a LCD device driving circuit for providing a driving voltage to the liquid crystal display device based on a display data signal and a plurality of liquid crystal driving signals; a dividing circuit for dividing a frequency of a horizontal synchronization signal having a period of one horizontal period, to obtain a period which is N times as large as that of the a horizontal synchronization signal, where N is an integer greater than zero; a duty control circuit for changing an ON duty ratio of the frequency-divided signal by using the frequency-divided signal as a reference frequency; and a light source driving circuit for turning the light source ON/OFF based on a signal from the duty control circuit having the ON duty ratio set in the duty control circuit, wherein where a period of the vertical synchronization signal is M times as large as a period of the horizontal synchronization signal, and a remainder of M divided by N is A, each of the integer N and the value M is set to an integer greater than zero which satisfies the following expression: −1≦{( N/A )−2}≦1.
Claim 4
Dependent Claim 208 words
A liquid crystal display apparatus, comprising: a liquid crystal display device; a light source for illuminating the liquid crystal display device: a LCD device driving circuit for providing a driving voltage to the liquid crystal display device based on a display data signal and a plurality of liquid crystal driving signals; a dividing circuit for dividing a frequency of a horizontal synchronization signal having a period of one horizontal period, to obtain a period which is N times as large as that of the a horizontal synchronization signal, where N is an integer greater than zero; a duty control circuit for changing an ON duty ratio of the frequency-divided signal by using the frequency-divided signal as a reference frequency; and a light source driving circuit for turning the light source ON/OFF based on a signal from the duty control circuit having the ON duty ratio set in the duty control circuit, wherein where a period of the vertical synchronization signal is M times as large as a period of the horizontal synchronization signal, and a remainder of M divided by N is A, each of the integer N and the value M is set to an integer greater than zero which satisfies the following expression: −1≦{( N/A )−2}≦1.
Claim 5
Dependent Claim 226 words
A liquid crystal display apparatus, comprising: a liquid crystal display device; a light source for illuminating the liquid crystal display device; a LCD device driving circuit for providing a driving voltage to the liquid crystal display device based on a display data signal and a plurality of liquid crystal driving signals including a display data latch signal; a dividing circuit for dividing a frequency of the display data latch signal or a horizontal synchronization signal having a cycle of one horizontal period, to obtain a period which is M times as large as that of the display data latch signal or the horizontal synchronization signal, where M is an integer greater than zero; a duty control circuit for changing an ON duty ratio of the frequency-divided signal by using the frequency-divided signal as a reference frequency; and a light source driving circuit for turning the light source ON/OFF based on a signal from the duty control circuit having the ON duty ratio set in the duty control circuit, wherein where a period of the display data latch signal or the horizontal synchronization signal is tLP, and a rising edge of a light modulation signal with respect to the beginning of a frame period is offset by (B×tLP), the value B is set to an integer greater than zero which satisfies the following expression: −1≦{( M/B )−2}≦1.
Claim 6
Dependent Claim 226 words
A liquid crystal display apparatus, comprising: a liquid crystal display device; a light source for illuminating the liquid crystal display device; a LCD device driving circuit for providing a driving voltage to the liquid crystal display device based on a display data signal and a plurality of liquid crystal driving signals including a display data latch signal; a dividing circuit for dividing a frequency of the display data latch signal or a horizontal synchronization signal having a cycle of one horizontal period, to obtain a period which is M times as large as that of the display data latch signal or the horizontal synchronization signal, where M is an integer greater than zero; a duty control circuit for changing an ON duty ratio of the frequency-divided signal by using the frequency-divided signal as a reference frequency; and a light source driving circuit for turning the light source ON/OFF based on a signal from the duty control circuit having the ON duty ratio set in the duty control circuit, wherein where a period of the display data latch signal or the horizontal synchronization signal is tLP, and a rising edge of a light modulation signal with respect to the beginning of a frame period is offset by (B×tLP), the value B is set to an integer greater than zero which satisfies the following expression: −1≦{( M/B )−2}≦1.
Claim 7
Dependent Claim 137 words
A liquid crystal display apparatus, comprising: a liquid crystal display device; a light source for illuminating the liquid crystal display device; a LCD device driving circuit for providing a driving voltage to the liquid crystal display device based on a display data signal and a liquid crystal driving signal having a frame period T 1 ; a duty control circuit for changing an ON duty ratio of a signal having a period T 2 ; a light source driving circuit for turning the light source ON/OFF based on a signal having the ON duty ratio set in the duty control circuit, wherein where a remainder of T 1 divided by T 2 is A, the values of T 1 and T 2 are set so as to satisfy the following expression: −1≦{( T 2 / A )−2}≦1.
Claim 8
Dependent Claim 137 words
A liquid crystal display apparatus, comprising: a liquid crystal display device; a light source for illuminating the liquid crystal display device; a LCD device driving circuit for providing a driving voltage to the liquid crystal display device based on a display data signal and a liquid crystal driving signal having a frame period T 1 ; a duty control circuit for changing an ON duty ratio of a signal having a period T 2 ; a light source driving circuit for turning the light source ON/OFF based on a signal having the ON duty ratio set in the duty control circuit, wherein where a remainder of T 1 divided by T 2 is A, the values of T 1 and T 2 are set so as to satisfy the following expression: −1≦{( T 2 / A )−2}≦1.
Claim 9
Dependent Claim 135 words
An electronic device for providing a control signal for use in a liquid crystal display apparatus, the device comprising: means for providing a display data latch signal having a period of tLP; means for providing a scan start signal having a period of D×tLP and a driving duty ratio of 1/D; means for dividing a frequency of the display data latch signal by a division-number N so as to generate a frequency divided signal having a period of N×tLP; and means for outputting the control signal based on the frequency divided signal, wherein the value N and the value D are integer values, and where A is a remainder of D divided by the division-number N, the values D and the division-number N are selected so as to satisfy the following equations −1≦{( N/A −2}≦1.
Claim 10
Dependent Claim 135 words
An electronic device for providing a control signal for use in a liquid crystal display apparatus, the device comprising: means for providing a display data latch signal having a period of tLP; means for providing a scan start signal having a period of D×tLP and a driving duty ratio of 1/D; means for dividing a frequency of the display data latch signal by a division-number N so as to generate a frequency divided signal having a period of N×tLP; and means for outputting the control signal based on the frequency divided signal, wherein the value N and the value D are integer values, and where A is a remainder of D divided by the division-number N, the values D and the division-number N are selected so as to satisfy the following equations −1≦{( N/A −2}≦1.
Claim 11
Dependent Claim 114 words
An electronic device for providing a control signal for use in a liquid crystal display apparatus, the device comprising: means for providing a vertical synchronization signal having a period M times as large as that of a horizontal synchronization signal; means for dividing a frequency of the horizontal synchronization signal to obtain a frequency divided signal having a period which is N times as large as that of the horizontal synchronization signal; and means for outputting the control signal based on the frequency divided signal, wherein where A is a remainder of M divided by N, the values of N and M are selected so as to satisfy the following equation: −1≦{( N/A )−2}≦1.
Claim 12
Dependent Claim 114 words
An electronic device for providing a control signal for use in a liquid crystal display apparatus, the device comprising: means for providing a vertical synchronization signal having a period M times as large as that of a horizontal synchronization signal; means for dividing a frequency of the horizontal synchronization signal to obtain a frequency divided signal having a period which is N times as large as that of the horizontal synchronization signal; and means for outputting the control signal based on the frequency divided signal, wherein where A is a remainder of M divided by N, the values of N and M are selected so as to satisfy the following equation: −1≦{( N/A )−2}≦1.
Claim 13
Dependent Claim 145 words
An electronic device for providing a control signal for use in a liquid crystal display apparatus, the device comprising: means for providing a display data latch signal or a horizontal synchronization signal having a period of tLP; means for providing a light modulation signal having a rising edge which is offset by B×tLP with respect to a frame period, the light modulation signal for controlling a division of the display data latch signal or horizontal synchronization signal; means for dividing the display data latch signal or horizontal synchronization signal so as to obtain a frequency divided signal having a period of M×tLP; and means for outputting the control signal based on the frequency divided signal, wherein the value B is an integer value greater than zero and the values of B and M are selected so as to satisfy the following expression: −1≦{( M/B )−2}≦1.
Claim 14
Dependent Claim 145 words
An electronic device for providing a control signal for use in a liquid crystal display apparatus, the device comprising: means for providing a display data latch signal or a horizontal synchronization signal having a period of tLP; means for providing a light modulation signal having a rising edge which is offset by B×tLP with respect to a frame period, the light modulation signal for controlling a division of the display data latch signal or horizontal synchronization signal; means for dividing the display data latch signal or horizontal synchronization signal so as to obtain a frequency divided signal having a period of M×tLP; and means for outputting the control signal based on the frequency divided signal, wherein the value B is an integer value greater than zero and the values of B and M are selected so as to satisfy the following expression: −1≦{( M/B )−2}≦1.
Claim 15
Dependent Claim 87 words
An electronic device for providing a control signal for use in a liquid crystal display apparatus, the device comprising: means for providing a liquid crystal driving signal having a frame period T 1 ; and means for changing an ON duty ratio of a signal having a period T 2 , wherein where A is a remainder of T 1 divided by T 2 , the values T 1 and T 2 are selected to as to satisfy the following expression: −1≦{( T 2 / A −2}1.
Claim 16
Dependent Claim 87 words
An electronic device for providing a control signal for use in a liquid crystal display apparatus, the device comprising: means for providing a liquid crystal driving signal having a frame period T 1 ; and means for changing an ON duty ratio of a signal having a period T 2 , wherein where A is a remainder of T 1 divided by T 2 , the values T 1 and T 2 are selected to as to satisfy the following expression: −1≦{( T 2 / A −2}1.

References Cited (Backward Citations)

US5122791A Cited
US5184117A Cited
EP0406116A1 Cited
JPH0364895A Cited
US5105127A Cited
JPH04143722A Cited
EP0685831A1 Cited
US5539707A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2005-08-05 2006-02-04 2006-08-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2009-08-05 2010-02-04 2010-08-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2013-08-05 2014-02-04 2014-08-06 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag