VOLTAGE-BALANCED SERIAL ILED PIXEL AND DISPLAY

• US 20170352647A1
• Filed: 05/31/2017
• Published: 12/07/2017
• Est. Priority Date: 06/03/2016
• Status: Active Grant

• Current Assignee: X Display Company Technology Limited (Sensinnovat BVBA)
• Original Assignee: X-Celeprint Limited
• Inventors: Raymond, Brook, Cok, Ronald S., Meitl, Matthew
• Granted Patent: US 10,453,826 B2
• Time in Patent Office: Days
• 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 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/18 High density interconnect [HDI] connectors; Manufacturing methods related thereto
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A multi-color inorganic light-emitting diode (iLED) display includes a display substrate with a common voltage signal and a common ground signal and a plurality of multi-color pixels. In certain embodiments, each multi-color pixel includes a first color sub-pixel including two or more first iLEDs, a second color sub-pixel including one or more second iLEDs, and a third color sub-pixel including one or more third iLEDs. The two or more first iLEDs are serially connected between the common voltage signal and the common ground signal, the one or more second iLEDs are serially connected between the common voltage signal and the common ground signal, and the one or more third iLEDs are serially connected between the common voltage signal and the common ground signal.

Claims

1. A multi-color inorganic light-emitting diode (iLED) pixel, comprising:

a common voltage signal and a common ground signal;

a first color sub-pixel comprising two or more first iLEDs, each first iLED emitting a first color of light when provided with electrical power at a first voltage, the two or more first iLEDs serially connected between the common voltage signal and the common ground signal; and

a second color sub-pixel comprising one or more second iLEDs, each second iLED emitting a second color of light different from the first color when provided with electrical power at a second voltage different from the first voltage, the one or more second iLEDs serially connected between the common voltage signal and the common ground signal;

wherein the number of first iLEDs is different from the number of second iLEDs; and

wherein the first color sub-pixel and the second color sub-pixel comprise at least a portion of the multi-color iLED pixel.

2. The multi-color inorganic light-emitting diode (iLED) pixel of claim 1, comprising:

a third color sub-pixel comprising one or more third iLEDs each emitting a third color of light different from the first and second colors of light when provided with electrical power at a third voltage different from the first or second voltage, the one or more third iLEDs serially connected between the common voltage signal and the common ground signal.

3. The multi-color inorganic light-emitting diode (iLED) pixel of claim 2, wherein the first color is red and the first iLED is a red iLED that emits red light, the second color is green and the second iLED is a green iLED that emits green light, and the third color is blue and the third iLED is a blue iLED that emits blue light.

4. The multi-color inorganic light-emitting diode (iLED) pixel of claim 2, comprising two serially connected red iLEDs, one green iLED, and one blue iLED.

5. The multi-color inorganic light-emitting diode (iLED) pixel of claim 2, comprising three serially connected red iLEDs, two serially connected green iLEDs, and two serially-connected blue iLEDs.

6. The multi-color inorganic light-emitting diode (iLED) pixel of claim 1, comprising a pixel controller that provides control signals for controlling the first and second iLEDs, and wherein the control signals are adapted to control the first and second iLEDs to emit a desired amount of light from each color sub-pixel.

7. The multi-color inorganic light-emitting diode (iLED) pixel of claim 6, wherein the desired amount of light from each color sub-pixel is the same and a ratio of the first control signal to the second control signal is dependent on a ratio of the number of first iLEDs to the number of second iLEDs.

8. A method of making a multi-color inorganic light-emitting diode (iLED) pixel, comprising:

providing a display substrate having a common voltage signal and a common ground signal on the display substrate;

providing a first color sub-pixel comprising two or more first iLEDs on or over the display substrate, each first iLED emitting a first color of light when provided with electrical power at a first voltage, the two or more first iLEDs serially connected between the common voltage signal and the common ground signal; and

providing a second color sub-pixel comprising one or more second iLEDs on or over the display substrate, each second iLED emitting a second color of light different from the first color when provided with electrical power at a second voltage different from the first voltage, the one or more second iLEDs serially connected between the common voltage signal and the common ground signal;

wherein the number of first iLEDs is different from the number of second iLEDs; and

wherein the first color sub-pixel and the second color sub-pixel comprise at least a portion of the multi-color iLED pixel.

9. The method of claim 8, comprising providing a plurality of pixels on the display substrate.

10. The method of claim 8, comprising micro-transfer printing the first iLEDs from a first source substrate to the display substrate and micro-transfer printing the second iLED(s) from a second source substrate to the display substrate.

11. The method of claim 8, comprising providing an intermediate substrate, micro-transfer printing the first iLEDs from a first source substrate to the intermediate substrate and micro-transfer printing the second iLED(s) from a second source substrate to the intermediate substrate to form a pixel.

12. The method of claim 11, comprising providing a common voltage signal and a common ground signal on the intermediate substrate, serially connecting the first iLEDS between the common voltage signal and the common ground signal, and serially connecting the one or more second iLEDS between the common voltage signal and the common ground signal.

13. The method of claim 11, comprising micro-transfer printing the pixel from the intermediate substrate to the display substrate.

14. The method of claim 11, comprising providing a pixel controller that provides control signals to control the first and second iLEDs.

15. The method of claim 14, comprising providing a pixel controller that provides control signals for controlling the first and second iLEDs, and wherein the control signals are adapted to control the first and second iLEDs to emit the desired amount of light from each color sub-pixel.

16. The method of claim 15, wherein the desired amount of light from each sub-pixel is the same and comprising controlling the ratio of the first control signal to the second control signal to be dependent on the ratio of the number of first iLEDs to the number of second iLEDs.

17. A multi-color inorganic light-emitting diode (iLED) display, comprising:

a display substrate;

a common voltage signal and a common ground signal disposed on the display substrate; and

a plurality of multi-color iLED pixels disposed in an array in, on, or over the display substrate, each multi-color pixel comprising;

a first color sub-pixel comprising two or more first iLEDs, each first iLED emitting a first color of light when provided with electrical power at a first voltage, the two or more first iLEDs serially connected between the common voltage signal and the common ground signal;

a second color sub-pixel comprising one or more second iLEDs, each second iLED emitting a second color of light different from the first color when provided with electrical power at a second voltage different from the first voltage, the one or more second iLEDs serially connected between the common voltage signal and the common ground signal; and

a third color sub-pixel comprising one or more third iLEDs, each third iLED emitting a third color of light different from the first and second colors when provided with electrical power at a third voltage different from the first voltage or the second voltage, the one or more third iLEDs serially connected between the common voltage signal and the common ground signal; and

wherein the number of first iLEDs is different from the number of second iLEDs.

18. The multi-color inorganic light-emitting diode (iLED) display of claim 17, comprising a pixel controller that provides control signals for controlling the first, second, and third iLEDs, and wherein the control signals are adapted to control the first, second, and third iLEDs to emit a desired amount of light from each color sub-pixel, the desired amount of light from each color sub-pixel is the same, and the ratio of the first control signal to the second control signal is dependent on the ratio of the number of first iLEDs to the number of second iLEDs.