Circuit and method for driving an array of light emitting pixels

• US 9,852,689 B2
• Filed: 09/15/2016
• Issued: 12/26/2017
• Est. Priority Date: 09/23/2003
• Status: Active Grant

• Current Assignee: IGNIS Innovation Incorporated
• Original Assignee: IGNIS Innovation Incorporated
• Inventors: Nathan, Arokia, Vygranenko, Yuriy, Jafarabadiashtiani, Shahin, Servati, Peyman
• Primary Examiner(s): Dharia, Prabodh M
• Application Number:
  US15/266,474
• Publication Number:
  US 20170004769A1
• Time in Patent Office: 467 Days
• Field of Search: 345 76- 84, 345204-211, 345690-692, 370354, 347235, 315169, 315307, 315291
• CPC Class Codes: G09G 2300/0417 Special arrangements specific to the use of low carrier mobility technology
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 3/3241 the current through the light-emitting element being set using a data current provided by the data driver, e.g. by using a two-transistor current mirror
• CPC Class Codes: G09G 3/325 the data current flowing through the driving transistor during a setting phase, e.g. by using a switch for connecting the driving transistor to the data driver
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• CPC Class Codes: G09G 3/3283 in which the data driver supplies a variable data current for setting the current through, or the voltage across, the light-emitting elements
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/60 Circuit arrangements for operating LEDs comprising organic material, e.g. for operating organic light-emitting diodes [OLED] or polymer light-emitting diodes [PLED]
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A technique for driving a column of pixels that include light emitting elements. The technique incorporates feedback data provided from feedback data sources connected to the data line and to feedback line of the array, pixel driving circuit with feedback path. The technique can also include block of the reference elements for input signal corrections.

Claims

1. A pixel circuit for use in a display, the display comprising a plurality of pixels, each of the pixels comprising:

a light emitting element;

a drive use transistor for providing a drive current to the light emitting element; and

an on-pixel feedback circuit for generating a feedback voltage from a node through which a current proportional to the drive current passes, the feedback voltage representing the drive current and provided to a feedback line of the display.

2. The pixel circuit according to claim 1, wherein the feedback circuit comprises at least one of a resistor, a diode, or the light emitting element connected between the drive use transistor and a reference potential.

3. The pixel circuit according to claim 2, wherein the reference potential is ground.

4. The pixel circuit according to claim 1, wherein each of the pixels further comprises a storage capacitor connected to ground or to the feedback circuit.

5. The pixel circuit according to claim 1, wherein the feedback circuit comprises a resistor connected between the drive use transistor and a reference potential providing the feedback voltage at a level proportional to the drive current and wherein the current proportional to the drive current comprises the drive current.

6. The pixel circuit according to claim 1, wherein each of the pixels further comprises a current mirror structure for generating the current proportional to the drive current.

7. The pixel circuit according to claim 6, wherein the feedback circuit comprises at least one of a resistor, a diode, or a light emitting element.

8. The pixel circuit according to claim 6, wherein the feedback circuit comprises a resistor connected between the current mirror structure and a reference potential providing the feedback voltage at a level proportional to the drive current.

9. The pixel circuit according to claim 1, wherein the feedback circuit comprises the light emitting element, and wherein the light emitting element is connected between the drive use transistor and the reference potential.

10. The pixel circuit according to claim 1, wherein the feedback circuit comprises a diode connected between the drive use transistor and a reference potential to provide the feedback voltage.

11. The pixel circuit according to claim 1, wherein the feedback circuit forms an on-pixel feedback conductive path between the drive use transistor and a reference potential.

12. The pixel circuit according to claim 1, wherein said light emitting element is an organic light emitting diode.

13. The pixel circuit according to claim 1, wherein each of the pixels further comprises a storage capacitor connected to the gate of the drive use transistor and a feedback transistor coupled between the feedback circuit and the feedback line.