IP Library › Granted Patent US 12,394,390
Granted Patent B2
US 12,394,390 · App. 18/603,157 · Granted Aug 19, 2025

Source driver having charge share line connecting output lines and display apparatus

Inventor: Kenichi Shigeta (Yokohama, JP)
Assignee: LAPIS Technology Co., Ltd.
G09G3/3696G09G2320/0247G09G2320/045G09G2330/021
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Quick Facts
Patent No.
US 12,394,390
App. No.
18/603,157
Granted
Aug 19, 2025
Kind
B2
Abstract

A source driver includes: output amplifiers, supplying pixel drive voltages to source lines of a display device based on a video signal; a charge share line, having a charge share switch able to connect output lines outputting the pixel drive voltages; a common voltage line, connected to a common voltage electrode of the display device; a first power supply line, supplying a first voltage; a switch part, able to connect the charge share line and the common voltage line with the first power supply line; and a control part, including a power off detection circuit that detects stoppage of supply of the first voltage. When it is detected that the first power supply line is off, the control part short-circuits the source lines by the charge share line and connects the charge share line and the common voltage line with the first power supply line by the switch part.

Claims (36)

1. A source driver comprising:

a plurality of output amplifiers, supplying a plurality of pixel drive voltages respectively corresponding to a plurality of pixels to each of a plurality of source lines of a display device based on a video signal;

a charge share line, having a charge share switch provided to be able to connect output lines outputting the plurality of pixel drive voltages of the plurality of output amplifiers;

a common voltage line, connected to a common voltage electrode of the display device;

a first power supply line, supplying a first voltage;

a switch part, provided to be able to connect the charge share line and the common voltage line with the first power supply line; and

a control circuit, comprising a first power off detection circuit that detects stoppage of supply of the first voltage from the first power supply line, wherein, in response to the first power off detection circuit detecting that the first power supply line is off, the control circuit short-circuits the plurality of source lines by the charge share line and connects the charge share line and the common voltage line with the first power supply line by the switch part.

2. The source driver according to claim 1 , further comprising:

a ground line, connected to a ground potential, wherein

the switch part is further configured to be able to connect the charge share line and the common voltage line with the ground line; and

in response to the first power off detection circuit detecting that the first power supply line is off, the control circuit connects the charge share line and the common voltage line with the ground line by the switch part.

3. The source driver according to claim 2 , wherein

the switch part comprises a first switch that is able to connect the common voltage line to the ground line, a second switch that is able to connect the charge share line to the common voltage line, and a third switch that is able to connect the first power supply line to the common voltage line.

4. The source driver according to claim 3 , further comprising:

a second power supply line, supplying a second voltage, wherein

the switch part further comprises a fourth switch that is able to connect the second power supply line to the common voltage line; and

the control circuit comprises a second power off detection circuit that detects stoppage of supply of the second voltage from the second power supply line, wherein, in response to the second power off detection circuit detecting that the second power supply line is off, the control circuit connects the second power supply line to the common voltage line.

5. A display apparatus comprising:

a display device; and

a source driver, comprising:

a plurality of output amplifiers, supplying a plurality of pixel drive voltages respectively corresponding to a plurality of pixels to each of a plurality of source lines of the display device based on a video signal;

a charge share line, having a charge share switch provided to be able to connect output lines outputting the plurality of pixel drive voltages of the plurality of output amplifiers;

a common voltage line, connected to a common voltage electrode of the display device;

a first power supply line, supplying a first voltage;

a switch part, provided to be able to connect the charge share line and the common voltage line with the first power supply line; and

a control circuit, comprising a first power off detection circuit that detects stoppage of supply of the first voltage from the first power supply line, wherein, in response to the first power off detection circuit detecting that the first power supply line is off, the control circuit short-circuits the plurality of source lines by the charge share line and connects the charge share line and the common voltage line with the first power supply line by the switch part.

6. The display apparatus according to claim 5 , wherein

the source driver further comprises a ground line connected to a ground potential;

the switch part is further configured to be able to connect the charge share line and the common voltage line with the ground line; and,

in response to the first power off detection circuit detecting that the first power supply line is off, the control circuit connects the charge share line and the common voltage line with the ground line by the switch part.

7. The display apparatus according to claim 6 , wherein

the switch part comprises a first switch that is able to connect the common voltage line to the ground line, a second switch that is able to connect the charge share line to the common voltage line, and a third switch that is able to connect the first power supply line to the common voltage line.

8. The display apparatus according to claim 7 , wherein

the source driver further comprises a second power supply line that supplies a second voltage;

the switch part further comprises a fourth switch that is able to connect the second power supply line to the common voltage line; and

the control circuit comprises a second power off detection circuit that detects stoppage of supply of the second voltage from the second power supply line, wherein, in response to the second power off detection circuit detecting that the second power supply line is off, the control circuit connects the second power supply line to the common voltage line.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 14, 2024
From: SHIGETA, KENICHI
To: LAPIS TECHNOLOGY CO., LTD.
Reel/Frame 066761/0726 →
Priority Claims (1)
JP 2023-039255 · Mar 14, 2023 · national
Continuity (1)
Related Publication 20240312430A1 · Sep 19, 2024
References Cited (3)
US 20120280961A1 · Son · 2012 [cited by examiner]
US 20140320464A1 · Ryu · 2014 [cited by examiner]
JP 2002149120 · 2002 [cited by applicant]
Cited By (1)
US 12,682,820