US-12620350-B2 - Pixel circuit, display apparatus including the pixel circuit, and electronic apparatus including the pixel circuit

US12620350B2US 12620350 B2US12620350 B2US 12620350B2US-12620350-B2

Abstract

A pixel circuit includes a driving transistor which generates a driving current based on a data signal, a light emitting element which emits light based on the driving current, a pulse signal applying block which outputs an emission control signal based on a pulse data voltage and a timing signal and a push-pull transistor which applies an initialization voltage to a first electrode of the light emitting element in response to the emission control signal. The light emitting element may stop emitting based on the emission control signal.

Inventors

Kwihyun KIM
Byong-Deok Choi
Sehyun Lee
Sunhwa Lee
June-Hee Lee
Kyunghoon Chung
Yong-Duck Kim

Assignees

SAMSUNG DISPLAY CO., LTD.
IUCF-HYU (INDUSTRY-UNIVERSITY COOPERATION FOUNDATION HANYANG UNIVERSITY)

Dates

Publication Date: 20260505
Application Date: 20250425
Priority Date: 20240620

Claims (20)

1 . A pixel circuit comprising: a driving transistor which generates a driving current based on a data signal; a light emitting element which emits light based on the driving current; a pulse signal applying block which outputs an emission control signal based on a pulse data voltage and a timing signal; and a push-pull transistor which applies an initialization voltage to a first electrode of the light emitting element in response to the emission control signal, wherein the light emitting element stops emitting based on the emission control signal.
2 . The pixel circuit of claim 1 , wherein the push-pull transistor comprises a control electrode receiving the emission control signal, a first electrode receiving the initialization voltage, and a second electrode connected to the first electrode of the light emitting element.
3 . The pixel circuit of claim 1 , further comprising an emission control transistor which applies the initialization voltage to a control electrode of the driving transistor.
4 . The pixel circuit of claim 3 , wherein an absolute value of a threshold voltage of the push-pull transistor is equal to an absolute value of a threshold voltage of the emission control transistor.
5 . The pixel circuit of claim 2 , further comprising an emission transistor which outputs the driving current to the first electrode of the light emitting element.
6 . The pixel circuit of claim 5 , wherein an absolute value of a threshold voltage of the push-pull transistor is equal to an absolute value of a threshold voltage of the emission transistor.
7 . The pixel circuit of claim 1 , wherein the pulse signal applying block comprises: a pulse writing transistor which applies the pulse data voltage to a pulse control node in response to a write gate signal; and an inverting block which outputs the emission control signal based on a voltage of the pulse control node.
8 . The pixel circuit of claim 7 , wherein the inverting block comprises: a first inverter transistor comprising a control electrode connected to the pulse control node, a first electrode receiving a first power voltage, and a second electrode connected to an output node; and a second inverter transistor comprising a control electrode connected to the pulse control node, a first electrode receiving a second power voltage, and a second electrode connected to the output node.
9 . The pixel circuit of claim 8 , wherein the second power voltage is applied to a second electrode of the light emitting element.
10 . The pixel circuit of claim 8 , further comprising an emission transistor comprising a control electrode connected to the output node, a first electrode connected to the driving transistor, and a second electrode connected to the light emitting element, wherein: the push-pull transistor comprises a control electrode connected to the output node, a first electrode receiving the initialization voltage, and a second electrode connected to the first electrode of the light emitting element, the emission transistor is a P-type transistor, and the push-pull transistor is an N-type transistor.
11 . The pixel circuit of claim 1 , wherein: the driving transistor comprises a control electrode connected to a first node, a first electrode connected to a second node, and a third electrode connected to a third node, the pixel circuit comprises: a writing transistor which applies a data voltage based on the data signal to the second node in response to a write gate signal; a compensation transistor which connects the first node and the third node in response to the write gate signal; an initialization transistor which applies the initialization voltage to the first node in response to a previous write gate signal; and an emission transistor which connects the third node and a fourth node in response to the emission control signal, the first electrode of the light emitting element is connected to the fourth node, and the push-pull transistor comprises a control electrode receiving the emission control signal, a first electrode receiving the initialization voltage, and a second electrode connected to the fourth node.
12 . The pixel circuit of claim 11 , wherein: the timing signal is a sweep signal, a frame period in which the pixel circuit is driven comprises a writing period and an emission period, in the writing period, the write gate signal has an activation level, and the writing transistor is turned on, and in the emission period, the sweep signal is gradually decreased from a high level to a low level.
13 . The pixel circuit of claim 11 , wherein the emission transistor is a P-type transistor, and the push-pull transistor is an N-type transistor.
14 . The pixel circuit of claim 1 , wherein: the driving transistor comprises a control electrode connected to a first node, a first electrode connected to a second node, and a second electrode connected to a third node, the pixel circuit comprises: a writing transistor which applies a data voltage based on the data signal to the second node in response to a write gate signal; a compensation transistor which connects the first node and the third node in response to the write gate signal; an initialization transistor which applies the initialization voltage to the first node in response to a previous write gate signal; a first emission transistor which applies a first power voltage to the second node in response to an emission signal; a second emission transistor which connects the third node and a fourth node in response to the emission signal; and an emission control transistor which applies the first power voltage to the first node in response to the emission control signal, the first electrode of the light emitting element is connected to the fourth node, and the push-pull transistor comprises a control electrode receiving the emission control signal, a first electrode receiving the initialization voltage, and a second electrode connected to the fourth node.
15 . A display apparatus comprising: a display panel comprising a pixel circuit; a gate driver which outputs a gate signal to the display panel; a data driver which applies a data voltage and a pulse data voltage to the display panel based on a data signal; a driving controller which outputs the data signal to the data driver; and a sweep signal generator which outputs a timing signal to the display panel, wherein the pixel circuit comprises: a driving transistor which generates a driving current based on the data signal; a light emitting element which emits light based on the driving current; a pulse signal applying block which outputs an emission control signal based on the pulse data voltage and the timing signal; and a push-pull transistor which applies an initialization voltage to a first electrode of the light emitting element in response to the emission control signal, wherein the light emitting element stops emitting based on the emission control signal.
16 . The display apparatus of claim 15 , wherein the push-pull transistor comprises a control electrode receiving the emission control signal, a first electrode receiving the initialization voltage, and a second electrode connected to the first electrode of the light emitting element.
17 . The display apparatus of claim 16 , wherein the pixel circuit further comprises an emission control transistor which applies the initialization voltage to a control electrode of the driving transistor.
18 . The display apparatus of claim 17 , wherein an absolute value of a threshold voltage of the push-pull transistor is equal to an absolute value of a threshold voltage of the emission control transistor.
19 . The display apparatus of claim 16 , wherein the pixel circuit further comprises an emission transistor which outputs the driving current to the first electrode of the light emitting element.
20 . An electronic apparatus comprising: a display panel comprising a pixel circuit; a gate driver which outputs a gate signal to the display panel; a data driver which applies a data voltage and a pulse data voltage to the display panel based on a data signal; a driving controller which controls the gate driver and the data driver and outputs the data signal to the data driver, based on an input control signal; a processor which outputs the input control signal; and a sweep signal generator which outputs a timing signal to the display panel, wherein the pixel circuit comprises: a driving transistor which generates a driving current based on the data signal; a light emitting element which emits light based on the driving current; a pulse signal applying block which outputs an emission control signal based on the pulse data voltage and the timing signal; and a push-pull transistor which applies an initialization voltage to a first electrode of the light emitting element in response to the emission control signal, wherein the light emitting element stops emitting based on the emission control signal.

Description

This application claims priority to Korean Patent Application No. 10-2024-0079989, filed on Jun. 20, 2024, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which in its entirety is herein incorporated by reference. BACKGROUND 1. Field Embodiments supported by aspects of the present disclosure relate to a pixel circuit, a display apparatus including the pixel circuit, and an electronic apparatus including the pixel circuit. More particularly, embodiments of the present disclosure relate to a pixel circuit in which an emission efficiency is improved, a display apparatus including the pixel circuit, and an electronic apparatus including the pixel circuit improving the display quality. 2. Description of the Related Art Generally, a display apparatus includes a display panel and a display panel driver. The display panel includes a plurality of gate lines, a plurality of data lines, a plurality of emission lines, and a plurality of pixels. The display panel driver includes a gate driver providing a gate signal to the gate lines, a data driver providing a data voltage to the data lines, an emission driver providing an emission signal to the emission lines, and a driving controller controlling the gate driver, the data driver and the emission driver. Generally, a light emitting element initialization signal applied to a pixel circuit may be sequentially applied to pixel-rows. SUMMARY Embodiments supported by aspects of the present disclosure provide a pixel circuit in which an accuracy of an emission time and an emission efficiency is improved. Embodiments supported by aspects of the present disclosure also provide a display apparatus including the pixel circuit. Embodiments supported by aspects of the present disclosure also provide an electronic apparatus including the pixel circuit. According to embodiments, a pixel circuit may include a driving transistor which generates a driving current based on a data signal, a light emitting element which emits light based on the driving current, a pulse signal applying block which outputs an emission control signal based on a pulse data voltage and a timing signal and a push-pull transistor which applies an initialization voltage to a first electrode of the light emitting element in response to the emission control signal. The light emitting element may stop emitting based on the emission control signal. In an embodiment, the push-pull transistor may include a control electrode receiving the emission control signal, a first electrode receiving the initialization voltage, and a second electrode connected to the first electrode of the light emitting element. In an embodiment, the pixel circuit may further include an emission control transistor which applies the initialization voltage to a control electrode of the driving transistor. In an embodiment, an absolute value of a threshold voltage of the push-pull transistor may be equal to an absolute value of a threshold voltage of the emission control transistor. In an embodiment, the pixel circuit may further include an emission transistor which outputs the driving current to the first electrode of the light emitting element. In an embodiment, an absolute value of a threshold voltage of the push-pull transistor may be equal to an absolute value of a threshold voltage of the emission transistor. In an embodiment, the pulse signal applying block may include a pulse writing transistor which applies the pulse data voltage to a pulse control node in response to a write gate signal and an inverting block which outputs the emission control signal based on a voltage of the pulse control node. In an embodiment, the inverting block may include a first inverter transistor including a control electrode connected to the pulse control node, a first electrode receiving a first power voltage, and a second electrode connected to an output node and a second inverter transistor including a control electrode connected to the pulse control node, a first electrode receiving a second power voltage, and a second electrode connected to the output node. In an embodiment, the second power voltage may be applied to a second electrode of the light emitting element. In an embodiment, the pixel circuit may further include an emission transistor including a control electrode connected to the output node, a first electrode connected to the driving transistor, and a second electrode connected to the light emitting element. The push-pull transistor may include a control electrode connected to the output node, a first electrode receiving the initialization voltage, and a second electrode connected to the first electrode of the light emitting element. The emission transistor may be a P-type transistor, and the push-pull transistor may be an N-type transistor. In an embodiment, the driving transistor may include a control electrode connected to a first node, a first electrode connected to a second node, and a third electrode connected t