Display panel drive apparatus having a noise reducing driver
AssigneePanasonic Corporation
InventorsTakashi Iwami, Tomoaki Tatsumi
Life of this patent
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Abstract
A display panel drive apparatus which reduces noise to thereby prevent malfunction. A first switch connects based on pixel data between one of column electrodes of a display panel and a power supply line to which a pulsed supply voltage is applied. A second switch connects between the one column electrode and a ground line based on the pixel data. The first and second switches are used to apply pixel data pulses based on the pixel data to the one column electrode. In this scheme, the pixel data having a lower frequency in the vertical direction of the screen allows the second switch to send a smaller current to the ground line when compared with a case of the pixel data having a higher frequency.
Claims7
A display panel drive apparatus for driving a plasma display panel on pixel-by-pixel basis in accordance with pixel data derived from an input video signal, the display panel having a capacitive pixel cell at each portion of intersection of a plurality of row electrodes and a plurality of column electrodes, the drive apparatus comprising:
- a power supply circuit for producing a pulsed supply voltage having a predetermined peak voltage for application to a power supply line;
- a pixel data pulse generation circuit for producing a pixel data pulse having a voltage associated with the pixel data in accordance with the pulsed supply voltage for application to the column electrode, the pixel data pulse generation circuit including a first switch for connecting between the power supply line and one of the column electrodes in accordance with the pixel data, and a second switch for connecting the one column electrode to a ground line in accordance with the pixel data;
- and
- a controller for decreasing a current drive capability of said second switch as a frequency of the pixel data in a vertical direction of a screen of the display panel lowers,
- wherein said second switch is made up of a plurality of transistors each having a drain terminal directly connected to said one column electrode and a source terminal directly connected to said ground line, and said controller includes means for fixing at least one of said transistors to off state when said frequency of the pixel data in the vertical direction of said screen is lower than a predetermined frequency.
Dependencies are inferred from the claim text.