Via design for use in displays

• US 8,345,177 B2
• Filed: 02/13/2009
• Issued: 01/01/2013
• Est. Priority Date: 02/13/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Chang, Shih Chang, Gettemy, Shawn Robert, Xu, Ming, Chen, Cheng, Gu, Mingxia, Zhong, John Z
• Primary Examiner(s): Briggs, Nathanael R
• Application Number:
  US12/371,284
• Publication Number:
  US 20100207860A1
• Time in Patent Office: 1,418 Days
• Field of Search: 349/110, 349 42- 43
• US Class Current: 349/43
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer

Abstract

A liquid crystal display (LCD) is provided having transistors disposed within via holes having elongated (e.g., rectangular or oval) contact areas. The use of via holes having elongated contact areas allows an opaque mask defining an aperture for light transmission to be lengthened, thereby increasing the overall area of the aperture. The increase in the area of the aperture may increase the amount of light that can pass through the aperture.

Claims

1. A liquid crystal display (LCD) panel, comprising:

a backlight assembly capable of generating light;

a liquid crystal layer comprising a plurality of liquid crystals whose alignment is determined by a respective electric field, wherein the alignment of the liquid crystals determines the amount of light which passes through the liquid crystal layer from the backlight assembly; and

a thin film transistor (TFT) layer comprising a plurality of TFTs which, when operated, are capable of generating the respective electric fields, each TFT formed entirely within a respective elongated via hole associated with a respective pixel of the LCD panel, wherein the elongated via holes are longer in one dimension than in a perpendicular dimension within a cross-sectional plane corresponding to the plane of the TFT layer.

2. The LCD panel of claim 1, comprising an opaque mask layer at each pixel, wherein the opaque mask layer defines a light transmissive aperture over the liquid crystal layer at the respective pixel and wherein the opaque mask layer is sized to cover the respective elongated via hole at the respective pixel.

3. The LCD panel of claim 1, wherein the elongated via holes comprise one or more of rectangular via holes or oval via holes.

4. 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; and

a thin film transistor (TFT) disposed entirely within an elongated via hole, wherein the operation of the TFT generated the electric field, wherein the elongated via holes are longer in one dimension than in a perpendicular dimension within a cross-sectional plane corresponding to the plane of the LCD.

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

a thin film transistor (TFT) disposed entirely within a rectangular via hole;

a liquid crystal layer, wherein alignment of a plurality of liquid crystals within the liquid crystal layer is determined by operation of the TFT; and

an opaque mask defining an aperture over the liquid crystal layer, wherein the opaque mask covers the rectangular via hole.

6. The LCD of claim 5, wherein each pixel comprises a backlight assembly capable of generating light which is modulated based on the alignment of the plurality of liquid crystals at the pixel.

7. The LCD of claim 5, wherein the thin film transistor comprises a source connected to a data line, a drain connected to a pixel electrode, and a gate connected to a scanning line.

8. The LCD of claim 5, wherein the rectangular via hole is about 9 μ

m×

4 μ

m or about 7 μ

m×

5 μ

m.

9. The LCD of claim 5, wherein the contact area provided by the rectangular via hole is about 36 μ

m².

10. The LCD of claim 5, wherein the LCD comprises a fringe field switched (FFS) LCD.

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

a non-square via hole housing a transistor, wherein the entire transistor is housed in the non-square via hole;

a plurality of liquid crystals whose alignment is determined by operation of the transistor; and

an opaque mask defining an aperture over the plurality of liquid crystals such that light may pass through the aperture if the plurality of liquid crystals is suitably aligned, wherein the opaque mask covers the non-square via hole.

12. The LCD of claim 11, wherein the non-square via hole is longer in one dimension than in a second, perpendicular dimension.

13. 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 via hole housing a transistor, wherein the via has a non-square contact area, and wherein the entire transistor is housed in the via hole;

a plurality of liquid crystals whose alignment is determined by operation of the transistor; and

an opaque mask defining an aperture over the plurality of liquid crystals, wherein the opaque mask covers the via hole.

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

a liquid crystal layer comprising a plurality of liquid crystals whose alignment determines the light transmission properties of the liquid crystal layer;

a thin film transistor (TFT) layer comprising a thin film transistor capable of affecting the alignment of the plurality of liquid crystals, wherein the TFT is housed within a via hole having an elongated contact area, and wherein a source electrode and a drain electrode of the TFT is housed within the via hole;

an opaque mask covering the via hole and defining an aperture through which light can pass, wherein the aperture defined by the opaque mask is larger in area than a comparable aperture which would be defined if the via hole had a square contact area and substantially the same amount of contact area.

15. The LCD of claim 14, comprising a backlight assembly capable of emitting light through the aperture and the plurality of liquid crystals when the plurality of liquid crystals is suitably aligned.

16. The LCD of claim 14, wherein the via hole has a rectangular or oval contact area.

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

forming a thin film transistor (TFT) in a via hole at each pixel, wherein each via hole has an elongated contact area, and wherein the entire TFT is formed within the via hole;

providing a liquid crystal layer at each pixel such that operation of each TFT affects the alignment of a plurality of liquid crystals at the respective pixel; and

providing an opaque mask defining an aperture over the liquid crystal layer at each pixel such that the respective via hole is covered by the opaque mask.

18. The method of claim 17, wherein each via hole has a rectangular or oval contact area.