Undulating electrodes for improved viewing angle and color shift

• US 8,633,879 B2
• Filed: 02/13/2009
• Issued: 01/21/2014
• Est. Priority Date: 02/13/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Gu, Mingxia, Xu, Ming, Chen, Cheng, Zhong, John Z., Chang, Shih Chang, Gettemy, Shawn Robert
• Primary Examiner(s): HALEY, JOSEPH R
• Application Number:
  US12/371,360
• Publication Number:
  US 20100207857A1
• Time in Patent Office: 1,803 Days
• Field of Search: 345/78, 345/173, 345/141, 349/141, 349/139, 349/143, 349/142, 349/40, 349/47
• US Class Current: 345/87
• 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

Abstract

The present disclosure generally provides for a variety of multi-domain pixel configurations that may be implemented in the unit pixels of an LCD display device, such as a fringe field switching LCD display panel. An LCD display device utilizing one or more of the presently disclosed techniques disclosed herein may exhibit improved display properties, such as viewing angle, color shift, and transmittance properties, relative to those exhibited by conventional multi-domain designs.

Claims

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

a plurality of unit pixels, wherein each of the plurality of unit pixels comprises an electrode, wherein the electrode comprises;

a first electrode strip; and

a second electrode strip;

wherein the first and the second electrode strips extend from a first end of the electrode at respective first and second angles with respect to a vertical axis of the LCD panel, the first and second angles having opposite angular directions with respect to a horizontal axis of the LCD panel;

wherein the first and the second electrode strips diverge from the first end over a first portion of the vertical length of the electrode to an intermediate point between the first end and a second end of the electrode, the second end being opposite the first end;

wherein, from the intermediate point, the first and second electrode strips converge over a second portion of the vertical length of the electrode at respective third and fourth angles with respect to the vertical axis of the LCD panel, the third and fourth angles having the same angular directions as the first and second angles, respectively;

wherein the first and second electrode strips converge at the second end of the electrode.

2. The LCD panel of claim 1, wherein the first and second angles are substantially equal in magnitude, and wherein the third and fourth angles are substantially equal in magnitude.

3. The LCD panel of claim 1, wherein, if the first and second portions of the vertical length of the electrode are substantially equal, the first and third angles are substantially equal in magnitude and the second and fourth angles are substantially equal in magnitude.

4. The LCD panel of claim 1, wherein, if the first portion of the vertical length of the electrode is greater than the second portion, the magnitude of the third angle is greater than the magnitude of the first angle, and the magnitude of the fourth angle is greater than the magnitude of the second angle.

5. The LCD panel of claim 1, wherein if the first portion of the vertical length of the electrode is less than the second portion, the magnitude of the third angle is less than the magnitude of the first angle, and the magnitude of the fourth angle is less than the magnitude of the second angle.

6. The LCD panel of claim 1, wherein the electrode comprises:

a third electrode strip coupled to the first and second ends of the electrode, the third electrode strip being directly adjacent to the first electrode strip and generally mimicking the shape of the first electrode strip in a generally parallel manner; and

a fourth electrode strip coupled to the first and second ends of the electrode, the fourth electrode strip being directly adjacent to the second electrode strip and generally mimicking the shape of the second electrode strip in a generally parallel manner.

7. The LCD panel of claim 1, wherein the plurality of unit pixels are arranged in a pixel array having rows and columns defined by scanning lines and data lines, respectively.

8. The LCD panel of claim 7, wherein each of the plurality of unit pixels comprises a thin film transistor (TFT) coupling the respective pixel to a scanning line and a data line.

9. The LCD panel of claim 8, comprising a light-opaque matrix disposed over the pixel array and defining a light-transmissive aperture over each of the unit pixels, wherein each light-transmissive aperture comprises a first vertical edge that generally mimics the shape of the first electrode strip in a generally parallel manner and a second parallel edge that generally mimics the shape of the second electrode strip in a generally parallel manner.

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

a pixel array comprising a plurality of unit pixels, wherein the plurality of unit pixels comprises;

a first set of unit pixels each comprising an electrode having one or more electrode strips, wherein the one or more electrode strips extend from a transistor end of the electrode at a first angle with respect to a vertical axis of the LCD panel in a first angular direction over a first distance along the vertical length of the electrode, and wherein the one or more electrode strips are positioned at a second angle with respect to the vertical axis in a second angular direction opposite the first angular direction over a second distance along the vertical length of the electrode; and

a second set of unit pixels each comprising an electrode having one or more electrode strips, wherein the one or more electrode strips extend from a transistor end of the electrode at the second angle in the first angular direction over the second distance along the vertical length of the electrode, and wherein the one or more electrode strips are positioned at the first angle in the second angular direction over the first distance along the vertical length of the electrode;

wherein the first and second distances are contiguous along the vertical length of the electrode, and wherein the first and second distances are not equal in magnitude.

11. The LCD panel of claim 10, wherein the first and second angles are substantially equal in magnitude.

12. The LCD panel of claim 10, wherein first distance is greater than the second distance.

13. The LCD panel of claim 10, wherein the plurality of unit pixels of the pixel array are arranged in rows and columns defined by scanning lines and data lines, respectively.

14. The LCD panel of claim 13, wherein each of the first set of unit pixels is coupled to one of a first set of scanning lines and respective data lines, and wherein each of the second set of unit pixels is coupled to one of a second set of scanning lines and respective data lines, wherein the first and second sets of scanning lines are arranged in an alternating manner along the vertical axis of the LCD panel.

15. The LCD panel of claim 14, wherein each of the data lines are oriented such that the portions of each data line disposed between adjacent scanning lines are parallel to the electrode strips of directly adjacent unit pixels, such that the data lines generally define a zigzag shape along the vertical length of the LCD panel.

16. The LCD panel of claim 14, wherein a general shape defined by the one or more electrode strips of each of the first set of unit pixels and a general shape defined by the one or more electrode strips of each of the second set of unit pixels are asymmetric with respect to the vertical and horizontal axes of the LCD panel.

17. The LCD panel of claim 16, wherein the one or more electrode strips of a unit pixel from the first set and the one or more electrode strips of a unit pixel from the second set directly adjacent to the unit pixel from the first set along a common data line are generally symmetric with respect to a horizontal axis therebetween.

18. The LCD panel of claim 16, wherein each of the unit pixels from the first set comprises an electrode layer having a shape that is substantially similar to the general shape defined by the electrode strips of each of the first set of unit pixels, wherein each of the unit pixels from the second set comprises an electrode layer have a shape that is substantially similar to the general shape defined by the electrode strips of each of the second set of unit pixels.

19. The LCD panel of claim 18, wherein the common electrode layer of a unit pixel from the first set and the common electrode layer of a unit pixel from the second set directly adjacent to the unit pixel from the first set along a common data line is generally symmetric about a horizontal axis therebetween.

20. The LCD panel of claim 18, wherein the electrode having the one or more electrode strips is a pixel electrode, and wherein the electrode layer is a common electrode layer.

21. The LCD panel of claim 20, wherein each of the unit pixels from the first and second sets of unit pixels comprises an insulating layer disposed between the pixel electrode and the common electrode layer.

22. The LCD panel of claim 21, wherein the LCD panel comprises a fringe field switching LCD panel.

23. The LCD panel of claim 10, comprising a light-opaque matrix disposed over the pixel array and defining a light-transmissive aperture over each of the first and second sets of unit pixels, wherein each light-transmissive aperture comprises vertical edges generally mimicking the shape of the electrode strips within the electrode of a corresponding unit pixel in a substantially parallel manner.

24. The LCD panel of claim 23, wherein a first light-transmissive aperture corresponding to a unit pixel from the first set and a second light-transmissive aperture corresponding to a unit pixel from the second set directly adjacent to the unit pixel from the first set along a common data line is generally symmetric with respect to a horizontal axis between the first and second light-transmissive apertures.