Display with light-emitting diodes

• US 10,714,009 B2
• Filed: 11/08/2019
• Issued: 07/14/2020
• Est. Priority Date: 12/04/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Lin, Chin-Wei, Lin, Hung Sheng, Chang, Shih Chang, Ono, Shinya
• Primary Examiner(s): Ma, Calvin C
• Application Number:
  US16/678,148
• Publication Number:
  US 20200074926A1
• Time in Patent Office: 249 Days
• Field of Search: 345 76, 345214, 345690
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2310/0202 Addressing of scan or signal lines
• CPC Class Codes: G09G 2310/0256 with the purpose of reversing the voltage across a light emitting or modulating element within a pixel
• CPC Class Codes: G09G 2320/0295 by monitoring each display pixel
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2340/0435 Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• CPC Class Codes: G09G 3/3275 Details of drivers for data electrodes
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/78651 Silicon transistors H01L29/78606 - H01L29/78645 take precedence
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

A display may have an array of pixels each of which has a light-emitting diode such as an organic light-emitting diode. A drive transistor and an emission transistor may be coupled in series with the light-emitting diode of each pixel between a positive power supply and a ground power supply. The pixels may include first and second switching transistors. A data storage capacitor may be coupled between a gate and source of the drive transistor in each pixel. Signal lines may be provided in columns of pixels to route signals such as data signals, sensed drive currents from the drive transistors, and predetermined voltages between display driver circuitry and the pixels. The switching transistors, emission transistors, and drive transistors may include semiconducting-oxide transistors and silicon transistors and may be n-channel transistors or p-channel transistors.

Claims

1. A pixel circuit comprising:

a positive power supply terminal;

a ground power supply terminal;

a light-emitting diode that is connected between the positive power supply terminal and the ground power supply terminal;

a silicon drive transistor that is connected in series with the light-emitting diode;

a first silicon emission transistor that is connected in series with the drive transistor and the light-emitting diode, wherein the first silicon emission transistor is interposed between the light-emitting diode and the silicon drive transistor;

a semiconducting-oxide switching transistor that is coupled to a gate of the silicon drive transistor; and

a second silicon emission transistor that is interposed between the silicon drive transistor and the positive power supply terminal.

2. The pixel circuit defined in claim 1, wherein the semiconducting-oxide switching transistor is coupled between the gate of the silicon drive transistor and a signal line.

3. The pixel circuit defined in claim 1, further comprising a capacitor that is coupled to the gate of the silicon drive transistor.

4. The pixel circuit defined in claim 3, wherein the capacitor is coupled between the gate of the silicon drive transistor and the positive power supply terminal.

5. The pixel circuit defined in claim 1, further comprising:

a silicon switching transistor that is coupled to an anode of the light-emitting diode.

6. The pixel circuit defined in claim 5, wherein the silicon switching transistor is coupled between the anode of the light-emitting diode and a signal line.

7. The pixel circuit defined in claim 1, further comprising:

a capacitor that is coupled between the gate of the silicon drive transistor and the positive power supply terminal; and

a silicon switching transistor that is coupled between an anode of the light-emitting diode and a signal line.

8. The pixel circuit defined in claim 1, further comprising:

a silicon switching transistor that is coupled to a node that is interposed between the silicon drive transistor and the second silicon emission transistor.

9. The pixel circuit defined in claim 8, wherein the silicon switching transistor is coupled between the node and a data line.

10. The pixel circuit defined in claim 1, further comprising:

a silicon switching transistor that is coupled between a source of the silicon drive transistor and a data line.

11. The pixel circuit defined in claim 10, wherein the silicon switching transistor is a first silicon switching transistor and wherein the pixel circuit further comprises:

a second silicon switching transistor that is coupled between an anode of the light-emitting diode and a signal line.

12. The pixel circuit defined in claim 1, wherein the first silicon emission transistor is a first p-channel silicon emission transistor, wherein the silicon drive transistor is a p-channel silicon drive transistor, wherein the semiconducting-oxide switching transistor is an re-channel semiconducting-oxide switching transistor, wherein the second silicon emission transistor is a second p-channel silicon emission transistor, and wherein the pixel circuit further comprises:

a p-channel silicon switching transistor that is coupled between a source of the p-channel silicon drive transistor and a data line; and

a capacitor that is coupled to the gate of the p-channel silicon drive transistor.

13. The pixel circuit defined in claim 1, wherein the first silicon emission transistor is a first p-channel silicon emission transistor, wherein the silicon drive transistor is a p-channel silicon drive transistor, wherein the semiconducting-oxide switching transistor is an re-channel semiconducting-oxide switching transistor, wherein the second silicon emission transistor is a second p-channel silicon emission transistor, and wherein the pixel circuit further comprises:

a first p-channel silicon switching transistor that is coupled between a source of the p-channel silicon drive transistor and a first signal line;

a capacitor that is coupled to the gate of the p-channel silicon drive transistor; and

a second p-channel silicon switching transistor that is coupled between an anode of the light-emitting diode and a second signal line.

14. A pixel circuit comprising:

a first power supply terminal;

a second power supply terminal;

a first silicon emission transistor, a silicon drive transistor, a second silicon emission transistor, and a light-emitting diode that are connected in series between the first power supply terminal and the second power supply terminal;

a semiconducting-oxide switching transistor that is coupled to a gate of the silicon drive transistor;

a first silicon switching transistor that is coupled between a source of the silicon drive transistor and a first signal line; and

a second silicon switching transistor that is coupled between an anode of the light-emitting diode and a second signal line.

15. The pixel circuit defined in claim 14, wherein the first silicon emission transistor is a first p-channel silicon emission transistor, wherein the silicon drive transistor is a p-channel silicon drive transistor, wherein the second silicon emission transistor is a second p-channel silicon emission transistor, wherein the semiconducting-oxide switching transistor is an n-channel semiconducting-oxide switching transistor, wherein the first silicon switching transistor is a first p-channel silicon switching transistor, wherein the second silicon switching transistor is a second p-channel silicon switching transistor, and wherein the first signal line is a data line.

16. The pixel circuit defined in claim 14, further comprising:

a capacitor that is coupled to the gate of the silicon drive transistor.

17. A pixel circuit comprising:

a first power supply terminal;

a second power supply terminal;

a p-channel silicon drive transistor, a p-channel silicon emission transistor, and a light-emitting diode that are connected in series between the first power supply terminal and the second power supply terminal;

an n-channel semiconducting-oxide switching transistor that is coupled to a gate of the p-channel silicon drive transistor;

a capacitor that is coupled between the gate of the p-channel silicon drive transistor and the first power supply terminal; and

a p-channel silicon switching transistor that is coupled between an anode of the light-emitting diode and a signal line.

18. The pixel circuit defined in claim 17, wherein the n-channel semiconducting-oxide switching transistor is coupled between the gate of the p-channel silicon drive transistor and a signal line.