Display control device with compensation for rounded or ringing waveforms
AssigneeSharp Kabushiki Kaisha
InventorMasaharu Yoshii
Life of this patent
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Abstract
A display control device for a dot-matrix type liquid-crystal display device with a plurality of common electrodes and data electrodes including a common electrode driver for successively applying a scan pulse to the common electrodes, and a data electrode driver for applying data signals each having black level or white level to the data electrodes. The data electrode drive is adapted to set each of the data signals to one of the black level and white level during a predetermined period of time immediately before the leading and trailing edges of the scan pulse and to the other of the black level and white level during a predetermined period of time immediately after the leading and trailing edges of the scan pulse.
Claims13
A display control device for a dot-matrix type liquid-crystal display device having a plurality of parallel common electrodes and parallel data electrodes intersecting said common electrodes, comprising:
- first means for successively applying scan pulses to said plurality of common electrodes, wherein the pulse width of each scan pulse corresponds to substantially one horizontal period;
- and
- second means for applying data signals, each having a first level voltage or a second level voltage, to said plurality of data electrodes,
- said second means further including level setting means to set each of said data signals to one of said first level voltage or second level voltage during a predetermined fixed period of time immediately before a leading or after a trailing edge of each of said scan pulses and to the other of said first level voltage or second level voltage during a predetermined fixed period of time immediately before the leading or after the trailing edge of each of said scan pulses, whereby noise is compensated irrespective of a pattern of an image to be displayed, so that a change between said first level voltage and said second level voltage occurs at least once during said predetermined fixed periods in one horizontal period regardless of voltages of said signals applied during periods other than said predetermined fixed periods to keep the number of times of level transitions in one horizontal period between said first level voltage and said second level voltage of data signals applied to each of said plurality of data electrodes substantially constant irrespective of the pattern of data signals of an image to be displayed.
A display control panel device for a dot-matrix type liquid-crystal display device having a plurality of common electrodes and data electrodes, comprising:
- first means for successively applying a scan pulse to said plurality of common electrodes;
- and
- second means for applying data signals each having first level voltage or second level voltage to said plurality of data electrodes,
- said second means further including level setting means to always require a data signal having said second level voltage to temporarily assume said first level voltage in a predetermined fixed period at one of a beginning or ending of a corresponding horizontal synchronous period and to always require a data signal having said first level voltage to temporarily assume said second level voltage in a predetermined fixed period at the other of a beginning or an ending of a corresponding horizontal synchronous period, whereby noise is compensated irrespective of a pattern of an image to be displayed, so that a change between said first level voltage and said second level voltage occurs at least once during said predetermined fixed periods in one horizontal period regardless of voltages of said signals applied during periods other than said predetermined fixed periods to keep the number of times of level transitions in one horizontal period between said first level voltage and said second level voltage of data signals applied to each of said plurality of data electrodes substantially constant irrespective of the pattern of data signals of an image to be displayed.
Dependencies are inferred from the claim text.