Light-emitting device (LED) and LED displaying circuit

• US 10,497,301 B2
• Filed: 04/17/2017
• Issued: 12/03/2019
• Est. Priority Date: 08/19/2016
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: InnoLux Corporation
• Inventors: Watsuda, Hirofumi
• Primary Examiner(s): Yeung, Matthew
• Application Number:
  US15/488,517
• Publication Number:
  US 20180053460A1
• Time in Patent Office: 960 Days
• Field of Search: None
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]

Abstract

A light-emitting device (LED) includes a primary driving circuit and a pixel. The primary driving circuit receives a system high voltage, a data signal, and a scan signal from a scan line, wherein the primary driving circuit has an output terminal. The pixel includes a plurality of light-emitting sub-pixel circuits. Each of the light-emitting sub-pixel is coupled to the output terminal of the primary driving circuit. Wherein, a frame period includes multiple equal fields, the light-emitting sub-pixel circuits are respectively corresponding to the fields and are activated according to a sequence as assigned. The light-emitting device display includes a plurality of light-emitting sub-pixel circuits are activated in raw, in column or both according to a sequence as assigned.

Claims

1. A light-emitting device, comprising:

a driving circuit, to provide a driving current in a frame period, according to a data signal comprising a low gray level range and a high gray level range;

a light-emitting diode, to emit light according to the driving current from the driving circuit; and

a selector, coupled to the driving circuit to control the driving circuit providing the driving current;

wherein the driving current comprises a first duty cycle corresponding to the high gray level range and a second duty cycle corresponding to the low gray level range, wherein the second duty cycle is a single value;

wherein, the second duty cycle is less than the first duty cycle,

wherein the driving circuit comprises;

a driving transistor, having a first terminal, a second terminal, and a gate terminal, wherein the first terminal of the driving transistor receives a first system high voltage;

a storage capacitor, having a first terminal and a second terminal, wherein the first terminal of the storage capacitor is coupled to the first terminal of the driving transistor, the second terminal of the storage capacitor is coupled to the gate terminal of the driving transistor;

a first switch transistor, having a first terminal, a second terminal, and a gate terminal, wherein the first terminal of the first switch transistor is coupled to the second terminal of the driving transistor, and the second terminal of the first switch transistor is coupled to the light-emitting diode to provide the driving current;

a second switch transistor, having a first terminal, a second terminal, and a gate terminal, wherein the first terminal of the second switch transistor receives the data signal, the second terminal of the second switch transistor is coupled to the gate terminal of the driving transistor, and the gate terminal of the second switch transistor is coupled to the selector and a scan line.

2. The light-emitting device according to claim 1, wherein the first duty cycle is 90-100 percent of the frame period and the second duty cycle is less than or equal to 50 percent of the frame period.

3. The light-emitting device according to claim 2, wherein the second duty cycle is less than or equal to 25 percent of the frame period.

4. The light-emitting device according to claim 1, wherein the high gray level range is mapped from a first current level to a maximum current level, and the low gray level range is mapped from a zero current level to a second current level larger than the first current level.

5. The light-emitting device according to claim 4, wherein the second current level is the maximum current level.

6. The light-emitting device according to claim 1, wherein the selector receives a scan signal on the scan line, wherein the selector further receives a digital control signal, a first emitting control signal according to the first duty cycle, a second emitting control signal according to the second duty cycle, and outputs a switch signal to the gate terminal of the first switch transistor.

7. The LED according to claim 1, wherein the selector receives a scan signal on the scan line, wherein the selector further receives a digital control signal and an erase signal according to the second duty cycle, wherein an emitting control signal according to the first duty cycle is received by the gate terminal of the first switch transistor, wherein an output of the selector s coupled to the gate terminal of the driving transistor to turn off the LED according to the erase signal.