Display device and driving method that compensates for unused frame time
First Claim
1. A method for driving a display device including an array of pixels arranged in a plurality of columns and a plurality of rows, said method comprising:
- defining a modulation period during which electrical signals corresponding to particular intensity values will be asserted on the pixels in said rows of said array;
receiving a first frame synchronization signal at the beginning of said modulation period;
dividing said modulation period into a plurality of time intervals;
receiving a second frame synchronization signal that defines a time difference between the end of the last one of said time intervals of said modulation period and receipt of said second frame synchronization signal;
defining a second modulation period;
dividing said second modulation period into said plurality of time intervals;
adjusting the duration of at least some of said time intervals in said second modulation period to spread said time difference over said second modulation period; and
updating a plurality of said rows in said array during said modulation period and said second modulation period such that said particular intensity values are asserted on said pixels in said rows of said array.
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Abstract
A novel method for driving a display having an array of pixels arranged in a plurality of columns and a plurality of rows includes the steps of defining a modulation period for a row of pixels, dividing the modulation period into a number of coequal time intervals equal to n times the number of rows in the array, receiving a multi-bit data word that indicates an intensity value, and updating the signal asserted on the pixel during a plurality of the time intervals such that the intensity value is displayed by the pixel. Note that n is an integer greater than zero. The method can be applied to all rows, which can be driven asynchronously. A display driver for performing the novel methods is also disclosed. The present invention facilitates driving the display at 100% bandwidth efficiency during each time interval in the modulation period.
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Citations
47 Claims
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1. A method for driving a display device including an array of pixels arranged in a plurality of columns and a plurality of rows, said method comprising:
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defining a modulation period during which electrical signals corresponding to particular intensity values will be asserted on the pixels in said rows of said array; receiving a first frame synchronization signal at the beginning of said modulation period; dividing said modulation period into a plurality of time intervals; receiving a second frame synchronization signal that defines a time difference between the end of the last one of said time intervals of said modulation period and receipt of said second frame synchronization signal; defining a second modulation period; dividing said second modulation period into said plurality of time intervals; adjusting the duration of at least some of said time intervals in said second modulation period to spread said time difference over said second modulation period; and updating a plurality of said rows in said array during said modulation period and said second modulation period such that said particular intensity values are asserted on said pixels in said rows of said array. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A display driver for driving an array of pixels arranged in a plurality of columns and a plurality of rows, said display driver comprising:
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a timer operative to generate a series of time values each associated with a respective one of a plurality of time intervals; a synchronization input operative to receive a series of frame synchronization signals; control logic operative to define a modulation period responsive to receiving a first frame synchronization signal, divide said modulation period into a plurality of time intervals, define a second modulation period responsive to receiving a second frame synchronization signal, divide said second modulation period into said plurality of time intervals, and update the electrical signals asserted on pixels in a plurality of said rows in said array during said modulation period and said second modulation period such that particular intensity values are asserted on said pixels in each of said modulation period and said second modulation period; and a compensator operative adjust the duration of at least some of said time intervals in said second modulation period depending on a time difference between the end of the last one of said time intervals in said modulation period and said second frame synchronization signal. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43)
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44. A display driver for driving an array of pixels arranged in a plurality of columns and a plurality of rows, said display driver comprising:
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a timer operative to generate a series of time values each associated with a respective one of a plurality of time intervals; a synchronization input operative to receive a series of frame synchronization signals; means for updating electrical signals asserted on the pixels in said array during a modulation period and a second modulation period such that particular intensity values are asserted on said pixels of said rows during said modulation period and said second modulation period; and means for adjusting the duration that said electrical signals are asserted on said pixels such that an unused modulation time at the end of said second modulation period is minimized. - View Dependent Claims (45)
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46. A method for driving a display device including an array of pixels arranged in a plurality of columns and a plurality of rows, said method comprising:
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defining a modulation period during which electrical signals corresponding to particular intensity values will be asserted on the pixels in said rows of said array; receiving a first frame synchronization signal at the beginning of said modulation period; dividing said modulation period into a plurality of time intervals; receiving a first-of-frame signal indicating the beginning of a first one of said time intervals in said modulation period; measuring a phase difference between said frame synchronization signal and said first-of-frame signal; receiving a second frame synchronization signal at the beginning of second modulation period; defining a second modulation period; dividing said second modulation period into said plurality of time intervals; and adjusting the duration of at least some of said time intervals in said second modulation period based on said phase difference in order to synchronize receipt of a subsequent frame synchronization signal and a subsequent first-of-frame signal.
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47. A display driver for driving an array of pixels arranged in a plurality of columns and a plurality of rows, said display driver comprising:
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a timer operative to generate a series of time values each associated with a respective one of a plurality of time intervals; a synchronization input operative to receive a series of frame synchronization signals; control logic operative to define a modulation period responsive to receiving a first frame synchronization signal, divide said modulation period into a plurality of time intervals, define a second modulation period responsive to receiving a second frame synchronization signal, and divide said second modulation period into said plurality of time intervals; a first-of-frame input terminal operative to receive a series of first-of-frame signals, each of said first-of-frame signals indicating the beginning of a first one of said time intervals in one of said modulation period and said second modulation period; and a compensator operative to measure a phase difference between said frame synchronization signal and said first-of-frame signal in said modulation period, and adjust the duration of at least some of said time intervals in said second modulation period based on said phase difference in order to synchronize receipt of a subsequent frame synchronization signal and a subsequent first-of-frame signal.
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Specification