Display device and method of driving a display device

Patent metadata

Field	Value
Publication number	US-12586496-B2
Application number	US-202418959606-A
Country	US
Kind code	B2
Filing date	Nov 26, 2024
Priority date	Nov 28, 2023
Publication date	Mar 24, 2026
Grant date	Mar 24, 2026

Abstract

A display device includes a display panel including an active pixel and a reference pixel, a reference pixel measurer which applies a reference data voltage and a gate voltage to the reference pixel, calculates a first threshold voltage and a second threshold voltage based on a driving current of the reference pixel and calculates a difference between the first threshold voltage and the second threshold voltage, and a driving controller which controls the reference pixel measurer and outputs a data signal based on the difference.

First claim

What is claimed is:

1 . A display device comprising:
a display panel including an active pixel and a reference pixel; a reference pixel measurer which applies a reference data voltage and a gate voltage to the reference pixel, calculates a first threshold voltage and a second threshold voltage based on a driving current of the reference pixel corresponding to the reference data voltage and calculates a difference between the first threshold voltage and the second threshold voltage; and a driving controller which controls the reference pixel measurer and outputs a data signal based on the difference between the first threshold voltage and the second threshold voltage, wherein the reference pixel comprises a reference driving transistor including a first control electrode which receives the reference data voltage, a second control electrode which receives the gate voltage, a first electrode which receive a first power voltage and a second electrode connected to a reference node, and wherein the active pixel comprises:
an active driving transistor including a first control electrode connected to a first active node, a first electrode which receives the first power voltage and a second electrode connected to a second active node;
an active scan transistor including a control electrode which receives a scan gate signal, a first electrode which receives a data voltage generated based on the data signal and a second electrode connected to the first active node;
an active sensing transistor including a control electrode which receives a sensing gate signal, a first electrode connected to a sensing line and a second electrode connected to the second active node; and
a light emitting element including an anode connected to the second active node and a cathode which receives a second power voltage.

2 . The display device of claim 1 , wherein the gate voltage is varied.

3 . The display device of claim 2 , wherein the gate voltage includes first to K-th gate voltages,
wherein K is a positive integer, wherein the reference data voltage includes a first reference data voltage to a second reference data voltage, and wherein the reference pixel measurer calculates a voltage-current curve function by applying the first reference data voltage to the second reference data voltage to the first control electrode of the reference driving transistor, calculates an error value based on the voltage-current curve function, calculates first to K-th error values corresponding to the first to K-th gate voltages, respectively, and generates an error function based on the first to K-th error values.

4 . The display device of claim 3 , wherein the error value is a value obtained by subtracting the second threshold voltage calculated by applying a second equation to the voltage-current curve function from the first threshold voltage calculated by applying a first equation to the voltage-current curve function.

5 . The display device of claim 4 , wherein the first threshold voltage is calculated by using the first equation,
wherein the first equation is

VTH
⁢

=

max
⁢

{

d
dVGS

⁢

(

d

dVGS

⁢

f

0
.
5

(

VGS
)

)

}

,

wherein
VTH denotes the first threshold voltage,
f 0.5 (VGS) denotes a 0.5 square curve function obtained by multiplying the voltage-current curve function to the power of 0.5, and

max
⁢

{

d
dVGS

⁢

(

d

dVGS

⁢

f

0
.
5

(

VGS
)

)

}

corresponds to a maximum value of values obtained by second differentiation of the 0.5 square curve function.

6 . The display device of claim 4 , wherein the second threshold voltage is calculated by using the second equation,
wherein the second equation is

VTH_CAL
=

I
⁢
2

*

VGS
⁢
1

-

I
⁢
1

*

VGS
⁢
2

I
⁢
2

-

I
⁢
1

,

wherein
VTH_CAL denotes the second threshold voltage,
VGS 1 denotes a voltage difference between the first control electrode and the second electrode of the reference driving transistor when a first sensing da

Assignees

• Samsung Display Co Ltd
• Ulsan Nat Inst Science & Tech Unist

Inventors

• Park Kyeongmin
• Bien Franklin Don
• Shin Kyeonghan
• Oh Seunghun
• Cho Haewan
• Choi Dongjin

Classifications

• G09G2310/08

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• G09G2300/0842

  forming a memory circuit, e.g. a dynamic memory with one capacitor · CPC title

• G09G2320/0242

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