Driving voltage control device, display device and driving voltage control method

• US 7,385,581 B2
• Filed: 03/04/2005
• Issued: 06/10/2008
• Est. Priority Date: 03/11/2004
• Status: Expired due to Fees

• Current Assignee: Godo Kaisha IP Bridge 1 (IP Bridge, Inc.)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Kojima, Tomokazu, Sakakibara, Tsutomu
• Primary Examiner(s): DHARIA, PRABODH M
• Application Number:
  US11/071,168
• Publication Number:
  US 20050200586A1
• Time in Patent Office: 1,194 Days
• Field of Search: 345/76, 345/82, 345/94, 345/95, 345/98, 345/100, 345/204, 345/211, 345/96, 345/147, 345/89, 345/208, 330/255, 374/170, 323/234, 327/536, 365/59, 365/63, 307/110
• US Class Current: 345/96
• CPC Class Codes: G09G 3/3666 with the matrix divided into sections
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers

Abstract

A driving voltage control device includes a first to fourth capacitor, and an output section. In the first mode, the first capacitor receives a first voltage and stores a corresponding amount of charge, the second capacitor receives a second voltage and stores a corresponding amount of charge, and the output section supplies either one of a voltage according to the amount of charge stored in the first capacitor or second capacitor to a first output node according to a predetermined timing. In the second mode, the third capacitor receives a third voltage and stores a corresponding amount of charge, the fourth capacitor receives a fourth voltage and stores a corresponding amount of charge, and the output section supplies either one of a voltage according to the amount of charge stored in the third capacitor or fourth capacitor to a second output node according to a predetermined timing.

Claims

1. A driving voltage control device operating in a first mode and in a second mode, and comprising a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, and an output section, wherein in the first mode:

the first capacitor receives a first voltage and stores an amount of charge according to a voltage value of the first voltage;

the second capacitor receives a second voltage and stores an amount of charge according to a voltage value of the second voltage; and

the output section supplies either one of a voltage according to the amount of charge stored in the first capacitor and a voltage according to the amount of charge stored in the second capacitor to a first output node according to a predetermined timing, and in the second mode;

the third capacitor receives a third voltage and stores an amount of charge according to a voltage value of the third voltage;

the fourth capacitor receives a fourth voltage and stores an amount of charge according to a voltage value of the fourth voltage; and

the output section supplies either one of a voltage according to the amount of charge stored in the third capacitor and a voltage according to the amount of charge stored in the fourth capacitor to a second output node according to a predetermined timing.

2. The driving voltage control device of claim 1, further comprising a voltage generation section, wherein in the first mode:

the voltage generation section generates the first and second voltages;

the first capacitor receives the first voltage generated by the voltage generation section; and

the second capacitor receives the second voltage generated by the voltage generation section, and in the second mode;

the voltage generation section generates the third and fourth voltages;

the third capacitor receives the third voltage generated by the voltage generation section; and

the fourth capacitor receives the fourth voltage generated by the voltage generation section.

3. The driving voltage control device of claim 2, further comprising a first differential amplifier circuit and a second differential amplifier circuit, wherein in the first mode:

the first differential amplifier circuit outputs the first voltage generated by the voltage generation section;

the second differential amplifier circuit outputs the second voltage generated by the voltage generation section;

the first capacitor receives the first voltage output by the first differential amplifier circuit; and

the second capacitor receives the second voltage output by the second differential amplifier circuit, and in the second mode;

the first differential amplifier circuit outputs the third voltage generated by the voltage generation section;

the second differential amplifier circuit outputs the fourth voltage generated by the voltage generation section;

the third capacitor receives the third voltage output by the first differential amplifier circuit; and

the fourth capacitor receives the fourth voltage output by the second differential amplifier circuit.

4. The driving voltage control device of claim 2, the voltage generation section including a first supply terminal and a second supply terminal, and the driving voltage control device further comprising:

a first switch connected between the first supply terminal and the first capacitor;

a second switch connected between the second supply terminal and the second capacitor;

a third switch connected between the first supply terminal and the third capacitor; and

a fourth switch connected between the second supply terminal and the fourth capacitor, wherein in the first mode;

the first supply terminal outputs the first voltage;

the second supply terminal outputs the second voltage;

the first and second switches are turned on; and

the third and fourth switches are turned off, and in the second mode;

the first supply terminal outputs the third voltage;

the second supply terminal outputs the fourth voltage;

the first and second switches are turned off; and

the third and fourth switches are turned on.

5. The driving voltage control device of claim 4, wherein the driving voltage control device is brought to a switching mode when switching between the first mode and the second mode, with the first to fourth switches being all turned off during the switching mode.

6. The driving voltage control device of claim 1, wherein in the first mode, the output section further supplies either one of the voltage according to the amount of charge stored in the first capacitor and the voltage according to the amount of charge stored in the second capacitor to the second output node.

7. The driving voltage control device of claim 1, wherein in the first mode, the output section further supplies either one of the voltage according to the amount of charge stored in the third capacitor and the voltage according to the amount of charge stored in the fourth capacitor to the second output node.

8. The driving voltage control device of claim 4, further comprising:

a first line having a first node, a second node, and third to sixth nodes present between the first node and the second node; and

a second line having a seventh node, an eighth node, and ninth to twelfth nodes present between the seventh node and the eighth node, the output section including;

a fifth switch connected between the third node and the first output node;

a sixth switch connected between the ninth node and the first output node;

a seventh switch connected between the fourth node and the second output node; and

an eighth switch connected between the tenth node and the second output node, wherein;

the first supply terminal is connected to the first node;

the second supply terminal is connected to the seventh node;

the first switch is connected between the fifth node and the first capacitor;

the second switch is connected between the eleventh node and the second capacitor;

the third switch is connected between the sixth node and the third capacitor;

the fourth switch is connected between the twelfth node and the fourth capacitor;

in the first mode, the fifth and sixth switches are turned on/off according to a predetermined timing; and

in the second mode, the seventh and eighth switches are turned on/off according to a predetermined timing.

9. The driving voltage control device of claim 8, wherein in the first mode, one of the seventh switch and the eighth switch is turned on.

10. The driving voltage control device of claim 8, further comprising a ninth switch connected between the second output node and one of the third capacitor and the fourth capacitor, wherein:

in the first mode, the ninth switch is turned on; and

in the second mode, the ninth switch is turned off.

11. A display device, comprising:

the driving voltage control device of claim 1;

a first display panel receiving, at a counter electrode thereof, a voltage supplied to the first output node included in the driving voltage control device;

a first source driver for supplying a data signal to the first display panel;

a second display panel receiving, at a counter electrode thereof, a voltage supplied to the second output node included in the driving voltage control device; and

a second source driver for supplying a data signal to the second display panel.

12. A driving voltage control device for supplying a predetermined voltage to a counter electrode of each of a first display panel and a second display panel, the driving voltage control device operating in a first mode and in a second mode, and comprising a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, and an output section, wherein in the first mode:

the first capacitor receives a first voltage from outside and stores an amount of charge according to a voltage value of the first voltage;

the second capacitor receives a second voltage from outside and stores an amount of charge according to a voltage value of the second voltage; and

the output section supplies either one of a voltage according to the amount of charge stored in the first capacitor and a voltage according to the amount of charge stored in the second capacitor to the counter electrode of the first display panel according to a predetermined timing, and in the second mode;

the third capacitor receives a third voltage from outside and stores an amount of charge according to a voltage value of the third voltage;

the fourth capacitor receives a fourth voltage from outside and stores an amount of charge according to a voltage value of the fourth voltage; and

the output section supplies ether one of a voltage according to the amount of charge stored in the third capacitor and a voltage according to the amount of charge stored in the fourth capacitor to the counter electrode of the second display panel according to a predetermined timing.

13. A driving voltage control method having a first mode and a second mode, and comprising a step (a), a step (b) and a step (c), wherein in the first mode:

the step (a) is a step of applying a first voltage to a first capacitor;

the step (b) is a step of applying a second voltage to a second capacitor; and

the step (c) is a step of supplying either one of a voltage according to an amount of charge stored in the first capacitor and a voltage according to an amount of charge stored in the second capacitor to a first output node according to a predetermined timing, and in the second mode;

the step (a) is a step of applying a third voltage to a third capacitor;

the step (b) is a step of applying a fourth voltage to a fourth capacitor; and

the step (c) is a step of supplying either one of a voltage according to an amount of charge stored in the third capacitor and a voltage according to an amount of charge stored in the fourth capacitor to a second output node according to a predetermined timing.

14. The driving voltage control method of claim 13, further comprising a step (d), wherein in the first mode, the step (d) is a step of supplying either one of the voltage according to the amount of charge stored in the first capacitor and the voltage according to the amount of charge stored in the second capacitor to the second output node.

15. The driving voltage control method of claim 13, further comprising a step (d), wherein in the first mode, the step (d) is a step of supplying either one of the voltage according to the amount of charge stored in the third capacitor and the voltage according to the amount of charge stored in the fourth capacitor to the second output node.