# US 2019/0378464 A1 · Light Emitting Unit, Driving Method Thereof, and Display Device

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- Number: US 2019/0378464 A1
- Document ID: US20190378464A1
- Status: Published application
- Kind: A1
- Application number: 16/424,870
- Filed: 2019-05-29
- Published: 2019-12-12
- Earliest claimed: 2018-06-08
- Assignees: Boe Technology Group Co., Ltd.
- Applicants: Boe Technology Group Co., Ltd.
- Inventors: Liang CHEN; Lei WANG; Xiaochuan CHEN; Minghua XUAN; Li XIAO; Dongni LIU; Shengji YANG; Pengcheng LU; Ning CONG; Detao ZHAO
- Web page: https://patentgrep.com/patent/US20190378464A1

## CPC

- G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element
- G09G 3/3291: in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
- H10K 50/30: Organic light-emitting transistors
- G09G 2300/043: Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver
- G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing
- G09G 2300/0842: forming a memory circuit, e.g. a dynamic memory with one capacitor
- H10K 59/12: Active-matrix OLED [AMOLED] displays
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)
- H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES

## Abstract

The present disclosure provides a light emitting unit, a driving method thereof, and a display device, belongs to the field of organic light emitting transistor (OLET) display technology, and can at least partially solve the problem of high power consumption of an existing OLET display technique. The light emitting unit includes an OLET and a driving circuit. The driving circuit is coupled to a control electrode and a first electrode of the OLET, and is configured to provide a data voltage to the control electrode of the OLET and provide a compensation voltage correlated with the data voltage to the first electrode of the OLET. A second electrode of the OLET is coupled to a first constant voltage terminal.

## Claims

### Claim 1

A light emitting unit, comprising an organic light emitting field effect transistor (OLET) and a driving circuit,
wherein the driving circuit is coupled to a control electrode and a first electrode of the OLET, and is configured to provide a data voltage to the control electrode of the OLET and provide a compensation voltage correlated with the data voltage to the first electrode of the OLET; and
a second electrode of the OLET is coupled to a first constant voltage terminal.

### Claim 2 (depends on 1)

The light emitting unit of claim 1, wherein the compensation voltage is positively correlated with the data voltage.

### Claim 3 (depends on 2)

The light emitting unit of claim 2, wherein the compensation voltage Vb and the data voltage Vdata have following relationship: Vb=βVdata, where β is a constant greater than one.

### Claim 4 (depends on 1)

The light emitting unit of claim 1, wherein the driving circuit comprises a voltage supply source having a first output terminal coupled to the control electrode of the OLET, and a second output terminal coupled to the first electrode of the OLET; and
the voltage supply source is configured to supply the data voltage at the first output terminal and supply the compensation voltage at the second output terminal.

### Claim 5 (depends on 1)

The light emitting unit of claim 1, wherein
the driving circuit comprises a voltage supply source and a voltage transformation circuit, an output terminal of the voltage supply source is coupled to the control electrode of the OLET and an input terminal of the voltage transformation circuit, and an output terminal of the voltage transformation circuit is coupled to the first electrode of the OLET;
the voltage supply source is configured to provide the data voltage at the output terminal thereof; and
the voltage transformation circuit is configured to convert the data voltage into the compensation voltage.

### Claim 6 (depends on 5)

The light emitting unit of claim 5, wherein
the voltage transformation circuit is an operational amplifier.

### Claim 7 (depends on 1)

The light emitting unit of claim 1, wherein the driving circuit comprises a first voltage supply source and a second voltage supply source,
an output terminal of the first voltage supply source is coupled to the control electrode of the OLET;
an output terminal of the second voltage supply source is coupled to the first electrode of the OLET;
the first voltage supply source is configured to supply the data voltage at the output terminal thereof; and
the second voltage supply source is configured to supply the compensation voltage correlated with the data voltage at the output terminal thereof.

### Claim 8 (depends on 1)

The light emitting unit of claim 1, wherein the driving circuit comprises a write circuit and a compensation circuit, wherein:
the write circuit is coupled to the control electrode of the OLET and the compensation circuit and is configured to supply the data voltage to the control electrode of the OLET and the compensation circuit; and
the compensation circuit is coupled to the first electrode of the OLET and the write circuit, and is configured to generate the compensation voltage according to the data voltage supplied by the write circuit, and provide the compensation voltage to the first electrode of the OLET.

### Claim 9 (depends on 8)

The light emitting unit of claim 8, wherein the compensation circuit comprises:
a voltage dividing resistor having a first terminal coupled to a second constant voltage terminal and a second terminal coupled to the first electrode of the OLET; and
a voltage dividing transistor having a control electrode coupled to the control electrode of the OLET and the write circuit, a first electrode coupled to the first electrode of the OLET, and a second electrode coupled to a third constant voltage terminal.

### Claim 10 (depends on 9)

The light emitting unit of claim 9, wherein
the control electrode of the voltage dividing transistor is coupled to the control electrode of the OLET through a protection resistor.

### Claim 11 (depends on 8)

The light emitting unit of claim 8, wherein
the write circuit comprises a switching transistor having a control electrode configured to receive a control signal, a first electrode configured to receive the data voltage, and a second electrode coupled to the control electrode of the OLET.

### Claim 12 (depends on 8)

The light emitting unit of claim 8, further comprising:
a storage capacitor having a first terminal coupled to the control electrode of the OLET and configured to maintain the data voltage of the control electrode of the OLET.

### Claim 13 (depends on 12)

The light emitting unit of claim 12, wherein
a second terminal of the storage capacitor is coupled to the first electrode of the OLET.

### Claim 14 (depends on 8)

The light emitting unit of claim 8, wherein the compensation circuit comprises an operational amplifier.

### Claim 15 (depends on 1)

A display device, comprising a plurality of light emitting units arranged in multiple rows and multiple columns, at least part of the plurality of light emitting units being the light emitting unit of claim 1.

### Claim 16 (depends on 1)

A display device, comprising a plurality of light emitting units arranged in multiple rows and multiple columns, each of the plurality of light emitting units being the light emitting unit of claim 1.

### Claim 17 (depends on 16)

The display device of claim 16, wherein the driving circuit of the light emitting unit comprises a voltage supply source having a first output terminal coupled to the control electrode of the OLET, and a second output terminal coupled to the first electrode of the OLET; and the voltage supply source is configured to supply the data voltage at the first output terminal and supply the compensation voltage correlated with the data voltage at the second output terminal, and
the voltage supply sources of the driving circuits of the plurality of light emitting units are integrated into one driver IC.

### Claim 18 (depends on 16)

The display device of claim 16, wherein the driving circuit of the light emitting unit comprises a first voltage supply source and a second voltage supply source; an output terminal of the first voltage supply source is coupled to the control electrode of the OLET; an output terminal of the second voltage supply source is coupled to the first electrode of the OLET; the first voltage supply source is configured to supply the data voltage at the output terminal thereof; and the second voltage supply source is configured to supply the compensation voltage correlated with the data voltage at the output terminal thereof, the first voltage supply sources of the driving circuits of the plurality of light emitting units are integrated into one driving chip, and the second voltage supply sources of the driving circuits of the plurality of light emitting units are integrated into another driving chip.

### Claim 19 (depends on 16)

The display device of claim 16, wherein the driving circuit of the light emitting unit comprises a write circuit and a compensation circuit; the write circuit is coupled to the control electrode of the OLET and the compensation circuit and is configured to supply the data voltage to the control electrode of the OLET and the compensation circuit; the compensation circuit is coupled to the first electrode of the OLET and the write circuit, and is configured to generate the compensation voltage according to the data voltage supplied by the write circuit, and provide the compensation voltage to the first electrode of the OLET; the display device further comprises a plurality of gate lines and a plurality of data lines, the write circuits of the light emitting units in a same row are coupled to a same gate line to receive a control signal through the gate line, and the write circuits of the light emitting units in a same column are coupled to a same data line to receive the data voltage through the data line.

### Claim 20 (depends on 1)

A driving method of a light emitting unit, the light emitting unit being the light emitting unit of claim 1, and the driving method comprising:
supplying a data voltage to the control electrode of the OLET, supplying a compensation voltage correlated with the data voltage to the first electrode of the OLET, and supplying a first constant voltage to the first constant voltage terminal such that the OLET emits light, wherein the first constant voltage is lower than the compensation voltage.