DRIVING APPARATUS AND METHOD FOR DISPLAY DEVICE AND DISPLAY DEVICE INCLUDING THE SAME

• US 20090009494A1
• Filed: 03/06/2008
• Published: 01/08/2009
• Est. Priority Date: 07/05/2007
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Sang-Keun
• Granted Patent: US 8,188,960 B2
• Time in Patent Office: Days
• US Class Current: 345/204
• CPC Class Codes: G09G 2330/06 Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation
• CPC Class Codes: G09G 3/3685 Details of drivers for data electrodes

Abstract

An apparatus for driving a display device includes a plurality of data driving integrated circuits which generates data voltages and a signal controller which inputs a first load signal to a data driving integrated circuit of the plurality of data driving integrated circuits to control the data driving integrated circuit. Each data driving integrated circuit of the plurality of data driving integrated circuits includes a load signal converter which generates a second load signal having a falling time which is different than a falling time of the first load signal.

Claims

1. An apparatus for driving a display device, the apparatus comprising:

a plurality of data driving integrated circuits which generates data voltages; and

a signal controller which inputs a first load signal to a data driving integrated circuit of the plurality of data driving integrated circuits to control the data driving integrated circuit,

wherein each data driving integrated circuit of the plurality of data driving integrated circuits comprises a load signal converter which generates a second load signal and a time when the second load signal begins to fall from high level to low level varies.

2. The apparatus of claim 1, wherein the load signal converter comprises:

a first voltage source;

a second voltage source;

a load signal buffer electrically connected to the first voltage source and the second voltage source, receiving the first load signal and outputting the second load signal;

a plurality of first transistors each connected in electrical parallel with each other, the plurality of second transistors being connected between the first voltage source and the load signal buffer and supplying bias current to the load signal buffer; and

a pseudo random binary sequence generator connected to the plurality of first transistors.

3. The apparatus of claim 2, wherein the pseudo random binary sequence generator includes a plurality of cascaded flip-flops, and an output terminal of each flip-flop of the plurality of flip-flops is connected to a control terminal of a corresponding first transistor of the plurality of first transistors.

4. The apparatus of claim 3, wherein a first flip-flop of the plurality of flip-flops receives an input signal through a logic circuit, the input signal having an arbitrary value and being selected from the output terminal of each flip-flop of the plurality of cascaded flip-flops of the pseudo random binary sequence generator.

5. The apparatus of claim 2, wherein respective sizes of each first transistor of the plurality of first transistors are different from each other.

6. The apparatus of claim 3, wherein the load signal buffer comprise:

a inverter;

a resistor connected to the first voltage source; and

a second transistor connected to the resistor;

a third transistor connected between the second transistor and the second voltage source; and

a fourth transistor, a five transistor, a sixth transistor and a seventh transistor connected in electrical series with each other and all connected between the first voltage source and the second voltage source,

wherein a control terminal and an input terminal of the second transistor are connected to a control terminal of the fourth transistor, and

a control terminal and an input terminal of the third transistor are connected to a control terminal of the seventh transistor.

7. The apparatus of claim 6, wherein

a control terminal of the sixth transistor and a control terminal of the seventh transistor receive the first load signal from the signal controller,

an output terminal of each first transistor of the plurality of first transistors is connected to an output terminal of the fourth transistor and an input terminal of the fifth transistor, and

an input terminal of the inverter is connected to an output terminal of the fifth transistor and an input terminal of the sixth transistor.

8. The apparatus of claim 7, wherein

the second transistor, the third transistor, the sixth transistor, and the seventh transistor are N-type transistors, and

the fourth transistor and the fifth transistor are P-type transistors.

9. The apparatus of claim 1, wherein the data driving integrated circuit further comprises:

a shift register;

a latch connected to the shift register;

a digital to analog converter connected to the latch; and

a buffer connected to the digital to analog converter.

10. The apparatus of claim 9, wherein the second load signal is applied to the latch and the buffer, and

when the second load signal is low, the latch sends image data stored in the latch to the digital to analog converter and

the buffer receives and amplifies a output of the digital to analog converter then outputs the amplified signal.

11. A display device comprising:

a plurality of data lines;

a plurality of data driving integrated circuits which applies data voltages to the plurality of data lines; and

a signal controller which inputs a first load signal to a data driving integrated circuit of the plurality of data driving integrated circuits to control the data driving integrated circuit,

wherein each data driving integrated circuit of the plurality of data driving integrated circuits includes a load signal converter which generates a second load signal and a time when the second load signal begins to fall from high level to low level is changeable according to a input signal

12. The display device of claim 11, wherein the load signal converter comprises:

a first voltage source;

a second voltage source;

a load signal buffer electrically connected to the first voltage source and the second voltage source, receiving the first load signal and outputting the second load signal;

an inverter connected to the current mirror;

a plurality of first transistors each connected in electrical parallel with each other, the plurality of first transistors being connected between the first voltage source and the load signal buffer and supplying bias current to the load signal buffer; and

a pseudo random binary sequence generator connected to the plurality of first transistors.

13. The display device of claim 12, wherein the pseudo random binary sequence generator includes a plurality of cascaded flip-flops, and an output terminal of each flip-flop of the plurality of flip-flops is connected to a control terminal of a corresponding second transistor of the plurality of first transistors.

14. The display device of claim 13, wherein a first flip-flop of the plurality of flip-flops receives an input signal through a logic circuit, the input signal having an arbitrary value and being selected from the output terminal of each flip-flop of the plurality of cascaded flip-flops of the pseudo random binary sequence generator.

15. The display device of claim 12, wherein respective sizes of each first transistor of the plurality of second transistors are different from each other.

16. The display device of claim 12, wherein the load signal buffer comprise:

a inverter;

a resistor connected to the first voltage source; and

a second transistor connected to the resistor;

a third transistor connected between the second transistor and the second voltage source; and

a fourth transistor, a five transistor, a sixth transistor and a seventh transistor connected in electrical series with each other and all connected between the first voltage source and the second voltage source,

wherein a control terminal and an input terminal of the second transistor are connected to a control terminal of the fourth transistor, and

a control terminal and an input terminal of the third transistor are connected to a control terminal of the seventh transistor.

17. The display device of claim 16, wherein:

a control terminal of the sixth transistor and a control terminal of the seventh transistor receive the first load signal from the signal controller,

an output terminal of each first transistor of the plurality of first transistors is connected to an output terminal of the fourth transistor and an input terminal of the fifth transistor, and

an input terminal of the inverter is connected to an output terminal of the fifth transistor and an input terminal of the sixth transistor.

18. The display device of claim 17, wherein

the second transistor, the third transistor, the sixth transistor, and the seventh transistor are N-type transistors, and

the fourth transistor and the fifth transistor are P-type transistors 19. A method for driving a display device, the method comprising:

outputting a control signal and a digital image signal including a first load signal to a data driving integrated circuit;

generating a second load signal with the data driving integrated circuit by receiving the first load signal and converting a time when the second load signal begins to fall from high level to low level;

generating a data voltage corresponding to the digital image signal in response to the time when the second load signal begins to fall from high level to low level; and

applying the data voltage to a data line to display an image.