Liquid crystal display backplane layouts and addressing for non-standard subpixel arrangements

• US 7,397,455 B2
• Filed: 06/06/2003
• Issued: 07/08/2008
• Est. Priority Date: 06/06/2003
• Status: Expired due to Term

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Credelle, Thomas Lloyd, Elliott, Candice Hellen Brown, Han, Seok Jin, Schlegel, Matthew Osborne
• Primary Examiner(s): Mengistu; Amare
• Assistant Examiner(s): Chow; Yuk
• Application Number:
  US10/456,838
• Publication Number:
  US 20040246404A1
• Time in Patent Office: 1,859 Days
• Field of Search: 345 87-103, 345/690, 345/698, 345694-695, 345204-214, 345 82- 83, 345/64, 345/211, 345/589, 345/55, 349/109, 349/97, 340/815.45, 362/555
• US Class Current: 345/88
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• 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 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

Liquid crystal display backplane layouts and addressing for non-standard subpixel arrangements are disclosed. A liquid crystal display comprises a panel and a plurality of transistors. The panel substantially comprises a subpixel repeating group having an even number of subpixels in a first direction. Each thin film transistor connects one subpixel to a row and a column line at an intersection in one of a group of quadrants. The group comprises a first quadrant, a second quadrant, a third quadrant and a fourth quadrant, wherein the thin film transistors are formed in a backplane structure adjacent to intersections of the row and column lines. The thin film transistors are also substantially formed in more than one quadrant in the backplane structure.

Claims

1. A liquid crystal display comprising:

a display panel substantially comprising a plurality of a subpixel repeating group tiled across said display panel in a regular pattern;

the subpixel repeating group comprises two rows of an even number of subpixels;

wherein each row of subpixels comprises at least two same-colored subpixels;

each said subpixel having an associated thin film transistor (TFT) connecting to said subpixel at an intersection of a row line and a column line;

said thin film transistor being formed in a corner of said subpixel in one of a group of quadrants with respect to said subpixel, the group comprising a first quadrant, a second quadrant, a third quadrant and a fourth quadrant such that the associated thin film transistors are substantially formed in at least two different quadrants with respect to their associated subpixels;

a quadrant location of said associated TFT determining to which row line and to which column line a subpixel is connected and wherein the associated TFT of each of said same-colored subpixels in both rows is formed in a quadrant of its respective subpixel so as to connect all same-colored subpixels in both rows to a common row line; and

driver circuitry configured to send image signals and polarity signals to said subpixels in one of a row and column direction such that same colored subpixels in said subpixel repeating group connected to said common row line forming a first direction are driven by alternating polarity signals.

2. The liquid crystal display of claim 1, wherein the polarity signals implement a 1×

1 dot inversion scheme.

3. The liquid crystal display of claim 1, wherein the polarity signals implement a 1×

2 dot inversion scheme.

4. The liquid crystal display of claim 1, wherein substantially every two incidences of a same colored subpixels along the first direction have a different polarity.

5. The liquid crystal display of claim 1, wherein the panel has at least a first region and a second region of subpixels such that each thin film transistor associated with a subpixel in the first region is formed substantially in a first numbered quadrant, and each thin film transistor associated with a subpixel in the second region is formed substantially in a second number quadrant different from the first numbered quadrant.

6. The liquid crystal display of claim 1, wherein the subpixel repeating group substantially comprises the pattern:

R G B G

B G R G.

7. The liquid crystal display of claim 1, wherein the subpixel repeating group substantially comprises the pattern:

R B G B

G B R B.

8. The liquid crystal display of claim 1, wherein the subpixel repeating group substantially comprises the pattern:

R G B G

R G B G

B G R G

B G R G.

9. A method for creating a liquid crystal display, said display comprising a display panel substantially comprising a plurality of a subpixel repeating group tiled across said display panel in a regular pattern;

said subpixel repeating group comprising an even number of subpixels in a first direction, the method comprising;

choosing a subpixel repeating group such that the subpixel repeating group comprises two rows of an even number of subpixels wherein each row of subpixels comprises at least two same-colored subpixels;

choosing a dot inversion scheme to drive the subpixels; and

for each subpixel in said repeating group, placing an associated thin film transistor in a quadrant of said subpixel; and

wherein the associated TFT of each of said same-colored subpixels in both rows is placed in a quadrant of its respective subpixel so as to connect all same-colored subpixels in both rows to a common row line such that said dot inversion scheme, when effected on said subpixels, causes same colored subpixels to be driven by alternating polarity signals.

10. The method of claim 9, wherein placing thin film transistors reduces any image degradation due to parasitic capacitances at the subpixel.

11. The method of claim 9, wherein the dot inversion scheme is 1×

1 dot inversion scheme.

12. The method of claim 9, wherein the dot inversion scheme is 1×

2 dot inversion scheme.

13. The method of claim 9, wherein the subpixel repeating group substantially comprises the pattern:

R G B G

B G R G.

14. The method of claim 9 wherein said subpixel repeating group substantially comprises the pattern:

R B G B

G B R B.

15. The method of claim 9 wherein said subpixel repeating group substantially comprises the pattern:

R G B G

R G B G

B G R G

B G R G.

16. A liquid crystal display comprising:

a display panel substantially comprising a plurality of a subpixel repeating group tiled across said display panel in a regular pattern;

the subpixel repeating group comprises two rows of an even number of subpixels;

wherein each row of subpixels comprises at least two same-colored subpixels;

said two rows of subpixels being connected to three row lines;

each subpixel having an associated thin film transistor with a gate, source, and drain;

each gate of each thin film transistor being connected to one of said three row lines such that, when said row lines are activated according to a polarity scheme, successive same colored subpixels in each row of the group are driven with alternating polarity signals.

17. The liquid crystal display of claim 16, further comprising:

at least two adjacent subpixel repeating groups, and

a row line that connects to transistors of the adjacent subpixel repeating groups such that same colored subpixels in a same row having alternating polarity.

18. A liquid crystal display comprising:

a display panel substantially comprising a plurality of a subpixel repeating group the subpixel repeating group comprises two rows of an even number of subpixels;

wherein each row of subpixels comprises at least two same-colored subpixels;

each said subpixel having an associated thin film transistor (TFT) connecting to said subpixel at an intersection of a row line and a column line;

said TFT being formed in a corner of said subpixel in one of a group of quadrants with respect to said subpixel, the group comprising first, second, third and fourth quadrants such that the associated TFTs are substantially formed in at least two different quadrants with respect to their associated subpixels;

a quadrant location of said associated TFT within said subpixel determining to which row line and to which column line a subpixel is connected;

said quadrant locations of all TFTs on said display panel implementing a row-and-column-line connection pattern and wherein the associated TFT of each of said same-colored subpixels in both rows is formed in a quadrant of its respective subpixel so as to connect all same-colored subpixels in both rows to a common row line; and

driver circuitry configured to send image signals and polarity signals to said subpixels along one of a row line and column line;

said polarity signals implementing a polarity scheme which, when implemented in conjunction with said row-and-column-line connection pattern of said TFTs, reduces image artifacts on said display panel.

19. A liquid crystal display comprising:

a display panel substantially comprising a plurality of a subpixel repeating group tiled across said display panel in a regular pattern;

the subpixel repeating group comprises subpixels in first and second primary colors;

wherein, when the plurality of subpixel repeating groups is repeated across said display panel, said subpixels in said first and second primary colors alternate in columns on said display panel;

each said subpixel having an associated thin film transistor (TFT) connecting to said subpixel at an intersection of a row line and a column line;

said thin film transistor being formed in a corner of said subpixel in one of a group of quadrants with respect to said subpixel, the group comprising a first quadrant, a second quadrant, a third quadrant and a fourth quadrant such that the associated thin film transistors are substantially formed in at least two different quadrants with respect to their associated subpixels;

a quadrant location of said associated TFT determining to which row line and to which column line in a subpixel is connected and wherein the associated TFT of each first and second primary color subpixel is formed in a quadrant of said respective subpixel such that only subpixels in one primary color are connected to a common column line; and

driver circuitry configured to send image signals and polarity signals to said subpixels in one of a row and column direction such that same colored subpixels in said subpixel repeating group connected to said common column line are driven by alternating polarity signals.