Display apparatus

• US 20050219236A1
• Filed: 03/23/2005
• Published: 10/06/2005
• Est. Priority Date: 03/30/2004
• Status: Active Grant

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation), Tottori Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Morita, Satoshi, Sano, Yutaka
• Granted Patent: US 7,453,450 B2
• Time in Patent Office: Days
• US Class Current: 345/211
• CPC Class Codes: G09G 2320/0223 Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes
• CPC Class Codes: G09G 3/3688 suitable for active matrices only

Abstract

A liquid crystal display apparatus is constituted whereby multiple source driver circuits provided with a driver IC are connected to the periphery of a liquid crystal display panel, and power supply voltages supplied from the outside are sequentially supplied from a specific source driver circuit to an adjacent source driver circuit, and a wire resistance calculation wire is formed for the driver IC in the voltage supply direction upstream, and is approximately equivalent to the signal wires extending from the upstream driver IC to the adjacent driver IC in the voltage supply direction downstream. The driver IC calculates the wire resistance by impressing a certain calculated voltage to one end of the wire resistance calculation wire, and then detects the voltage on the other end, calculates the amounts of the drop in voltage level based on the calculated wire resistance, and outputs the power supply voltages increased by the calculated respective amounts of the voltage drop to the downstream driver IC. Accordingly, a display apparatus is provided for preventing a drop in the power supply voltages sequentially supplied, thereby inhibiting malfunctioning of the driver ICs, resulting in improved display quality.

Claims

1. A display apparatus configured in such manner that a plurality of adjacent driver circuits, each mounting a driver IC on a circuit board are connected to the periphery of a display panel, said adjacent driver circuits being connected to each other by a connection wire formed on the said display panel, while a power supply voltage required for driving the said driver ICs and the said display panel is supplied from an external control circuit to at least one of the said driver circuits, and sequentially supplied from one of the said driver circuits to the driver circuit adjacent thereto, wherein:

a wire resistance calculation wire is formed for the said driver IC upstream in the voltage supply direction, and is approximately equivalent to a signal wire extending downstream from the said driver IC to the said driver IC on the driver circuit adjacent thereto in the voltage supply direction, and the said upstream driver IC calculates the wire resistance by impressing a certain calculated voltage on one end of the said wire resistance calculation wire, and then detects the voltage of the other end, calculates the drop in voltage level based on the calculated wire resistance, and outputs the power supply voltage increased by the calculated amount of the voltage drop to the said downstream driver circuit.

2. The display apparatus according to claim 1, wherein the said wire resistance calculation wire is formed to route from said circuit board in a tape form constituting the said driver circuit back to the said circuit board again via the said display panel.

3. The display apparatus according to claim 1, wherein each said driver IC comprises an power supply voltage input terminal to which the power supply voltage is inputted, a calculation voltage creation section that creates the calculation voltage used to calculate the wire resistance, a calculation voltage output terminal that outputs the calculation voltage supplied from the said calculation voltage creation section to one end of the said wire resistance calculation wire, a detection terminal to which the output voltage of the other end of the said wire resistance calculation wire is inputted, a wire resistance calculation section that calculates the wire resistance based on the calculation voltage and the voltage detected on the said detection terminal, a power supply voltage adding section that is supplied with the power supply voltage inputted from the said power supply voltage input terminal, calculates the amount of the drop in voltage level based on the calculated wire resistance, and adds the calculated amount of the voltage drop to the power supply voltage, and a power supply voltage output terminal that outputs the power supply voltage supplied by the said power supply voltage adding section.

4. The display apparatus according to claim 1, wherein the power supply voltage includes an operation power supply voltage for each of the said driver ICs, and a display power supply voltage for the said display panel.

5. A display apparatus configured in such manner that a plurality of adjacent driver circuits, each mounting a driver IC on a circuit board, are connected to the periphery of a display panel, said adjacent driver circuits being connected to each other by a connection wire formed on the said display panel, while a power supply voltage required for driving the said driver ICs and the said display panel is supplied from an external control circuit to at least one of the said driver ICs, and sequentially supplied from one of the said driver ICs to the driver IC adjacent thereto, wherein:

a wire resistance calculation wire is formed for the said driver IC upstream in the voltage supply direction, and is approximately equivalent in length to that of a signal wire extending downstream from the said upstream driver IC to the driver IC adjacent thereto in the voltage supply direction, and the said upstream driver IC calculates the wire resistance by impressing a certain calculated voltage on one end of the said wire resistance calculation wire, and after detecting the voltage of the other end, calculates the drop in voltage level based on the calculated wire resistance, and outputs the power supply voltage increased by the calculated amount of the voltage drop to the said downstream driver IC.

6. The display apparatus according to claim 5, wherein each said driver IC comprises a power supply voltage input terminal to which the power supply voltage is inputted, a calculation voltage creation section that creates the calculation voltage used to calculate the wire resistance, a calculation voltage output terminal that outputs the calculation voltage supplied from said calculation voltage creation section to one end of the said wire resistance calculation wire, a detection terminal to which the output voltage of the other end of the said wire resistance calculation wire is inputted, a wire resistance calculation section that calculates the wire resistance based on the calculation voltage and the voltage detected on the said detection terminal, a power supply voltage adding section that is supplied with the power supply voltage inputted from the said power supply voltage input terminal, calculates the amount of the voltage drop based on the calculated wire resistance, and adds the amount of the voltage drop to the power supply voltage, and a power supply voltage output terminal that outputs the power supply voltage supplied from the said power supply voltage adding section.

7. The display apparatus according to claim 6, wherein the power supply voltage includes an operation power supply voltage for each of the said driver ICs, and a display power supply voltage for the said display panel.