Flat-panel display device
AssigneeSamsung Electron Devices Co., Ltd.
InventorSang-cheol Kim
Life of this patent
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Abstract
A flat-panel display device is disclosed which comprises m column electrodes, n row electrodes, a column electrode driver for driving the m column electrodes in response to pixel data, and a row electrode driver for driving the n row electrodes by a one-line-at-a-time scanning methode, the column electrode driver comprising a detector for checking whether or not the number of turned-on column electrodes among the m column electrodes is greater than a predetermined number and an on-time varying unit for shortening the on-time of the column electrodes in response to the output of the detector. The device has an effect of reducing power consumed by varying the on-time of the electrodes when more than the predetermined number of pixels are on.
Claims6
A flat-panel display device having first and second electrodes for displaying n.times.m pixel data, comprising:
- a first driver for driving the first electrodes responsive to a first signal;
- means for controlling the number of pixels to determine whether or not the number of turned-on pixels in one row among m rows is at least equal to a predetermined number, said means for counting including:
- first logic means for determining whether any bit of pixel data is on,
- second logic means for generating a counter clock signal responsive to the output of said first logic means and a data clock signal.
- a counter for counting the number of pixels in the on state utilizing the output of said second logic means, and
- third logic means for determining whether the predetermined number of pixels in the on state has been counted;
- means for generating a first frequency signal in response to first preselected outputs of said counting means, said means for generating a first frequency signal including:
- a first D-type positive-edge-triggered flip-flop having a clock signal port connected to said third logic means, a preset signal port, a data input port, and a clear signal port which receives a second signal,
- delaying means for delaying the output of said first D-type positive-edge-triggered flip-flop,
- a second D-type positive-edge-triggered flip-flop having a data input port connected to said delaying means to receive the output signal of said delaying means, and a clock signal port for receiving an inverted second signal;
- and
- means for generating a first frequency in response to an output signal from said second D-type positive-edge-triggered flip-flop;
- means for generating a second frequency signal in response to second preselected outputs of said counting means;
- and
- means for varying the on-time of the first electrodes in response to the first and second frequency signals.
A displaying method for a flat-panel display device including a display having first and second electrodes for displaying n columns X m rows of pixels data, a first driver for driving said first electrode, and a second driver for driving said second electrode, comprising the steps of:
- counting a number of turned-on pixels in one row among the m rows;
- comparing the number of pixels counted in said counting step with a predetermined number;
- providing a first on-time signal to the first driver when the number of pixels counted in said counting step is at least equal to the predetermined number;
- outputting a second on-time signal to the first driver when the number of pixels counted in said counting step is less than predetermined number;
- and
- maintaining the pixels counted in said counting step in a turned-on state for a first time interval responsive to the first on-time signal and maintaining the pixels counted in said counting step in a turned-on state for a second time interval responsive to a second on-time signal wherein the first time interval is less than the second time interval.
Dependencies are inferred from the claim text.