IP Library Granted Patent US 9,202,413
Granted Patent B2
US 9,202,413 · App. 14/529,374 · Granted Dec 1, 2015

Drive method of display device

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Quick Facts
Patent No.
US 9,202,413
App. No.
14/529,374
Granted
Dec 1, 2015
Kind
B2
Abstract

A drive method of a display device includes the steps of: performing threshold voltage cancel processing at least once, which changes a potential of a second node of a display device toward a potential obtained by subtracting a threshold voltage of a drive transistor from a potential of a first node by applying a given drive voltage to one source/drain region of the drive transistor from a feeding line while maintaining the potential of the first node; and then, performing writing processing which applies a video signal to the first node from a data line through a write transistor, wherein the sum of lengths of periods in which the threshold voltage cancel processing is performed is so set as to be shorter as a frame frequency becomes higher.

Claims (36)

1. A display device comprising:

a plurality of pixel circuits, each of the plurality of pixel circuits including a light emitting element, a write transistor, a drive transistor and a capacitor,

wherein the drive transistor is configured to, in a threshold voltage cancel processing period, flow a correction current to the capacitor while the write transistor is supplying a reference potential from a video signal line, and

wherein a length of the threshold voltage cancel processing period is set so as to be shorter as a frame frequency becomes higher wherein the length of the threshold voltage cancel processing period is adjusted by changing a width of a scanning pulse corresponding to the threshold voltage cancel processing period without changing a width of a scanning pulse corresponding to the video signal writing period.

2. An electronic apparatus comprising the display device of claim 1 .

3. A display device comprising:

at least one sub-pixel that includes a light emitting element, a write transistor, a drive transistor and a capacitor;

a control circuit configured to:

perform a threshold voltage cancel processing operation comprising causing the drive transistor to flow a correction current to the capacitor while the write transistor is supplying a reference potential from a video signal line, and

adjust a per-frame-period aggregate amount of time that the threshold voltage cancel processing operation is performed based on a change in frame frequency without affecting a duration of a video signal writing operation.

4. The display device of claim 3 ,

wherein the control circuit is configured to perform the threshold voltage cancel processing operation multiple times each frame period, and

the per-frame-period aggregate amount of time that the threshold voltage cancel processing operation is performed is adjusted by at least one of:

adjusting durations of individual performances of the threshold voltage cancel processing operation in the frame period; and

adjusting a number of times the threshold voltage cancel processing operation is performed in the frame period.

5. The display device of claim 4 ,

wherein the per-frame-period aggregate amount of time that the threshold voltage cancel processing operation is performed is adjusted by at least adjusting a number of times the threshold voltage cancel processing operation is performed in the frame period.

6. The display device of claim 4 ,

wherein the per-frame-period aggregate amount of time that the threshold voltage cancel processing operation is performed is adjusted by a combination of:

adjusting durations of individual performances of the threshold voltage cancel processing operation in the frame period; and

adjusting a number of times the threshold voltage cancel processing operation is performed in the frame period.

7. An electronic apparatus comprising the display device of claim 3 .

8. A method of operating a display device that includes at least one sub-pixel that includes a light emitting element, a write transistor, a drive transistor and a capacitor, the method comprising:

performing a threshold voltage cancel processing operation comprising causing the drive transistor to flow a correction current to the capacitor while the write transistor is supplying a reference potential from a video signal line, and

adjust a per-frame-period aggregate amount of time that the threshold voltage cancel processing operation is performed based on a change in frame frequency without affecting a duration of a video signal writing operation.

9. The method of claim 8 , further comprising:

performing the threshold voltage cancel processing operation multiple times each frame period,

wherein the per-frame-period aggregate amount of time that the threshold voltage cancel processing operation is performed is adjusted by at least one of:

adjusting durations of individual performances of the threshold voltage cancel processing operation in the frame period; and

adjusting a number of times the threshold voltage cancel processing operation is performed in the frame period.

10. The method of claim 9 ,

wherein the per-frame-period aggregate amount of time that the threshold voltage cancel processing operation is performed is adjusted by at least adjusting a number of times the threshold voltage cancel processing operation is performed in the frame period.

11. The method of claim 9 ,

wherein the per-frame-period aggregate amount of time that the threshold voltage cancel processing operation is performed is adjusted by a combination of:

adjusting durations of individual performances of the threshold voltage cancel processing operation in the frame period; and

adjusting a number of times the threshold voltage cancel processing operation is performed in the frame period.

Assignments (5)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 18, 2025
From: JDI DESIGN AND DEVELOPMENT G.K.
To: MAGNOLIA BLUE CORPORATION
Reel/Frame 072039/0656 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 31, 2024
From: JOLED, INC.
To: JDI DESIGN AND DEVELOPMENT G.K.
Reel/Frame 066382/0619 →
CORRECTION BY AFFIDAVIT FILED AGAINST REEL/FRAME 063396/0671 Recorded Jun 12, 2023
From: JOLED, INC.
To: JOLED, INC.
Reel/Frame 064067/0723 →
SECURITY INTEREST Recorded Apr 20, 2023
From: JOLED, INC.
To: INCJ, LTD.
Reel/Frame 063396/0671 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 10, 2015
From: SONY CORPORATION
To: JOLED INC.
Reel/Frame 036090/0968 →