IP Library Granted Patent US 12,451,037
Granted Patent B2
US 12,451,037 · App. 18/355,578 · Granted Oct 21, 2025

Method of inspecting a pixel

Inventor: Pongok Park (Yongin-si, KR)
Assignee: SAMSUNG DISPLAY CO., LTD.
G09G3/006G09G3/32G09G2310/0275G09G2330/10G09G2330/12
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Quick Facts
Patent No.
US 12,451,037
App. No.
18/355,578
Granted
Oct 21, 2025
Kind
B2
Abstract

A method of inspecting a pixel includes measuring a first drain current by applying a first gate voltage with a first voltage interval to a gate terminal of a transistor included in a test pattern in a first voltage period, generating a first gate voltage-drain current graph based on the first drain current, measuring a second drain current by applying a second gate voltage which is lower than the first gate voltage with a second voltage interval which is different from the first voltage interval to the gate terminal of the transistor in a second voltage period which is different from the first voltage period, generating a second gate voltage-drain current graph based on the second drain current, and determining a defect of the transistor based on the first gate voltage-drain current graph and the second gate voltage-drain current graph.

Claims (44)

1. A method of inspecting a pixel, the method comprising:

measuring a first drain current by applying a first gate voltage with a first voltage interval to a gate terminal of a transistor included in a test pattern in a first voltage period;

generating a first gate voltage-drain current graph based on the first drain current;

measuring a second drain current by applying a second gate voltage which is lower than the first gate voltage with a second voltage interval which is different from the first voltage interval to the gate terminal of the transistor in a second voltage period which is different from the first voltage period;

generating a second gate voltage-drain current graph based on the second drain current; and

determining a defect of the transistor based on the first gate voltage-drain current graph and the second gate voltage-drain current graph.

2. The method of claim 1 , wherein the first drain current and the second drain current are different.

3. The method of claim 2 , wherein the first drain current is lower than the second drain current.

4. The method of claim 1 , wherein the first voltage interval is greater than the second voltage interval.

5. The method of claim 4 , wherein a compensation drain current other than the first drain current measured in the first voltage period is determined by using a lookup table in which the first drain current corresponding to the first gate voltage is stored.

6. A method of inspecting a pixel, the method comprising:

measuring a first drain current by applying a first gate voltage with a first voltage interval to a gate terminal of a transistor included in a test pattern in a first voltage period;

generating a first gate voltage-drain current graph based on the first drain current;

measuring a second drain current by applying a second gate voltage which is lower than the first gate voltage with a second voltage interval to the gate terminal of the transistor in a second voltage period which is different from the first voltage period;

generating a second gate voltage-drain current graph based on the second drain current;

measuring a third drain current by applying a third gate voltage which is lower than the second gate voltage with a third voltage interval to the gate terminal of the transistor in a third voltage period which is different from the first voltage period and the second voltage period;

generating a third gate voltage-drain current graph based on the third drain current; and

determining a defect of the transistor based on the first gate voltage-drain current graph, the second gate voltage-drain current graph, and the third gate voltage-drain current graph,

wherein at least two of the first voltage interval, the second voltage interval, and the third voltage interval are different from each other.

7. The method of claim 6 , wherein the first drain current, the second drain current, and the third drain current are different from each other.

8. The method of claim 7 , wherein the first drain current is lower than the second drain current.

9. The method of claim 8 , wherein the second drain current is lower than the third drain current.

10. The method of claim 6 , wherein the first voltage interval and the second voltage interval are greater than the third voltage interval.

11. The method of claim 10 , wherein a compensation drain current other than the first drain current measured in the first voltage period and the second drain current measured in the second voltage period is determined by using a lookup table in which the first drain current corresponding to the first gate voltage and the second drain current corresponding to the second gate voltage are stored.

12. The method of claim 6 , wherein the first voltage interval is greater than the second voltage interval and the third voltage interval.

13. The method of claim 12 , wherein a compensation drain current other than the first drain current measured in the first voltage period is determined by using a lookup table in which the first drain current corresponding to the first gate voltage is stored.

14. A method of inspecting a pixel, the method comprising:

determining at least two of a first transistor that generates a driving current, a second transistor that transmits a data voltage, and a third transistor that initializes a light emitting element, which are included in a test pattern;

measuring a first drain current by applying a first gate voltage with a first voltage interval to gate terminals of the at least two of the first transistor, the second transistor, and the third transistor, in a first voltage period;

generating a first gate voltage-drain current graph based on the first drain current;

measuring a second drain current by applying a second gate voltage which is lower than the first gate voltage with a second voltage interval to the gate terminals of the at least two of the first transistor, the second transistor, and the third transistor in a second voltage period which is different from the first voltage period;

generating a second gate voltage-drain current graph based on the second drain current;

measuring a third drain current by applying a third gate voltage which is lower than the second gate voltage with a third voltage interval to the gate terminals of the at least two of the first transistor, the second transistor, and the third transistor in a third voltage period which is different from the first voltage period and the second voltage period;

generating a third gate voltage-drain current graph based on the third drain current; and

determining defects of the at least two of the first transistor, the second transistor, and the third transistor based on the first gate voltage-drain current graph, the second gate voltage-drain current graph, and the third gate voltage-drain current graph,

wherein at least two of the first voltage interval, the second voltage interval, and the third voltage interval are different from each other.

15. The method of claim 14 , wherein the first drain current, the second drain current, and the third drain current are different from each other.

16. The method of claim 15 , wherein

the first drain current is lower than the second drain current, and

the second drain current is lower than the third drain current.

17. The method of claim 15 , wherein the first voltage interval is greater than the second voltage interval and the third voltage interval.

18. The method of claim 17 , wherein a compensation drain current other than the first drain current measured in the first voltage period is determined by using a lookup table in which the first drain current corresponding to the first gate voltage is stored.

19. The method of claim 14 , wherein the first voltage interval and the second voltage interval are greater than the third voltage interval.

20. The method of claim 19 , wherein a compensation drain current other than the first drain current measured in the first voltage period and the second drain current measured in the second voltage period is determined by using a lookup table in which the first drain current corresponding to the first gate voltage and the second drain current corresponding to the second gate voltage are stored.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 20, 2023
From: PARK, PONGOK
To: SAMSUNG DISPLAY CO., LTD.
Reel/Frame 064324/0583 →
Priority Claims (1)
KR 10-2022-0118572 · Sep 20, 2022 · national
Continuity (1)
Related Publication 20240096251A1 · Mar 21, 2024
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