Electrodes for use in displays

• US 8,587,758 B2
• Filed: 02/13/2009
• Issued: 11/19/2013
• Est. Priority Date: 02/13/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Chen, Cheng, Xu, Ming, Chang, Shih Chang, Gu, Mingxia, Gettemy, Shawn Robert
• Primary Examiner(s): Briggs, Nathanael R
• Application Number:
  US12/371,342
• Publication Number:
  US 20100207853A1
• Time in Patent Office: 1,740 Days
• Field of Search: 349/141, 349/110
• US Class Current: 349/141
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/134381 Hybrid switching mode, i.e. for applying an electric field with components parallel and orthogonal to the substrates
• CPC Class Codes: G02F 1/1393 the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 take precedence
• CPC Class Codes: G02F 2201/122 having a particular pattern

Abstract

A liquid crystal display (LCD) is provided having a discontinuous electrode. In certain embodiments, finger- or slit-like extensions of the discontinuous electrode may be shaped to reduce or eliminate disclinations of liquid crystals within a pixel aperture used to transmit light, where the liquid crystals are oriented in response to an electric field generated using the discontinuous electrode. Similarly, in other embodiments, the different portions of the discontinuous electrode may be lengthened to extend under an opaque mask or may not be linked at one end to reduce or eliminate the disclinations.

Claims

1. A liquid crystal display (LCD) comprising a plurality of pixels, each pixel comprising:

a liquid crystal layer, wherein alignment of a plurality of liquid crystals within the liquid crystal layer is determined by an electric field;

an opaque mask defining an aperture over the liquid crystal layer;

a circuitry layer beneath the liquid crystal layer, the circuitry layer capable of generating the electric field, the circuit layer comprising;

an insulating layer;

a first electrode formed on a first side of the insulating layer, the electrode comprising two or more finger-like regions that extend away from a thin film transistor in a first direction, wherein respective ends of the two or more finger-like regions extend beneath the opaque mask and have arcuate shapes, and wherein two or more portions of the two or more finger-like regions are substantially straight and parallel, thereby generating substantially zero electric field components operating in the first direction within the aperture; and

a second electrode formed on a second side of the insulating layer opposite the first side, wherein the second electrode comprises a common electrode.

2. The LCD of claim 1, wherein the respective ends of the two or more finger-like regions are connected by a crossbar region.

3. The LCD of claim 1, wherein the respective ends of the two or more finger-like regions are connected by a region proximate to the thin film transistor.

4. The LCD of claim 1, wherein the LCD comprises a fringe field switched (FFS) LCD.

5. The LCD of claim 1, wherein the first electrode comprises a pixel electrode.

6. The LCD of claim 1, wherein respective ends of the two or more finger-like regions comprise curved edges or curved transition regions.

7. The LCD of claim 1, wherein respective ends of the two or more finger-like regions are not connected by a linear segment of the first electrode running perpendicular to the respective ends.

22. The LCD of claim 1, wherein the substantially two or more substantially straight portions of the finger-like regions are substantially perpendicular to at least one side of the aperture.

8. An electronic device, comprising:

one or more input structures;

a storage structure encoding one or more executable routines;

a processor capable of receiving inputs from the one or more input structures and of executing the one or more executable routines when loaded in a memory; and

a liquid crystal display (LCD) capable of displaying an output of the processor, wherein the LCD comprises a plurality of pixels, each pixel comprising;

a liquid crystal layer comprising a plurality of liquid crystals whose alignment is determined by an electric field, wherein the alignment of the liquid crystals determines the amount of light which passes through the liquid crystal layer at the respective pixel;

an opaque mask defining an aperture over the liquid crystal layer;

an electrode formed on a first side of an insulating layer, wherein the electrode is used to generate the electric field, the electrode comprising two or more finger-like regions, wherein respective ends of the two or more finger-like regions extend beneath the opaque mask and have arcuate shapes, and wherein the electric field comprises substantially zero electric field components within the aperture that operate in a direction along which the two or more finger-like regions extend away from a thin film transistor; and

a common electrode formed along a length of a second side of the insulating layer opposite the first side.

9. The electronic device of claim 8, wherein the electronic device comprises a computer, a cellular telephone, a television, a gaming system, or a media player.

10. The electronic device of claim 8, wherein the respective ends of the two or more finger-like regions comprise one or more curved or angled portions.

11. A liquid crystal display (LCD) comprising a plurality of pixels, each pixel comprising:

a liquid crystal layer, wherein alignment of a plurality of liquid crystals within the liquid crystal layer is determined by an electric field;

an opaque mask defining an aperture over the liquid crystal layer; and

an electrode capable of generating the electric field, wherein the electrode comprises two or more finger-like regions comprising at least one terminal end having an arcuate shape, and wherein the at least one terminal end is disposed under the opaque mask.

12. The LCD of claim 11, wherein at least a portion of the two or more finger-like regions are disposed substantially under the opaque mask.

13. The LCD of claim 11, wherein the at least one terminal end comprises transitions to a crossbar region or thin film transistor (TFT) region linking the two or more finger-like regions.

14. The LCD of claim 11, wherein the electrode comprises a body having a substantially rectangular shape.

15. An electronic device, comprising:

one or more input structures;

a storage structure encoding one or more executable routines;

a processor capable of receiving inputs from the one or more input structures and of executing the one or more executable routines when loaded in a memory; and

a liquid crystal display (LCD) capable of displaying an output of the processor, wherein the LCD comprises a plurality of pixels, each pixel comprising;

a liquid crystal layer comprising a plurality of liquid crystals whose alignment is determined by an electric field;

an electrode used to generate the electric field, the electrode comprising two or more finger-like regions comprising at least one terminal region having an arcuate shape; and

an opaque mask substantially overlying the at least one terminal region.

16. The electronic device of claim 15, wherein the one or more input structures comprise a touch sensitive structure disposed with the LCD to form a touch screen.

17. A liquid crystal display (LCD) comprising a plurality of pixels, each pixel comprising:

an insulating layer;

a first electrode formed on a first side of the insulating layer;

a second electrode formed across a length of a second side of the insulating layer opposite the first side, the second electrode comprising two or more finger-like extensions, each having an arcuate end region that extends beneath an opaque mask, wherein two or more portions of the finger-like extensions that are not beneath the opaque mask generate an electric field comprising substantially zero electric field components operating in a direction along which the two or more finger-like portions extend away from a thin film transistor, and wherein the two or more portions of the finger-like extensions are substantially parallel with each other; and

a plurality of liquid crystals whose alignment is determined by an electric field generated between the first electrode and the second electrode.

18. The LCD of claim 17, wherein the arcuate end regions are connected by a crossbar or a region proximate to the thin film transistor.

19. The LCD of claim 17, comprising an opaque mask defining an aperture over the plurality of liquid crystals, wherein the arcuate end regions are disposed substantially beneath the opaque mask.

20. The LCD of claim 17, wherein the arcuate end regions comprise curved edges.

21. The LCD of claim 17, wherein the arcuate end regions comprise angled edges.