IP Library Granted Patent US 8,023,073
Granted Patent B2
US 8,023,073 · App. 11/521,010 · Granted Sep 20, 2011

Color filter display panel, thin film transistor array panel, liquid crystal display thereof, and method thereof

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Quick Facts
Patent No.
US 8,023,073
App. No.
11/521,010
Granted
Sep 20, 2011
Kind
B2
Abstract

A liquid crystal display (“LCD”) includes forming only a λ/4 plate between a polarizer and a display panel and setting a direction of an absorption axis of the polarizer and a slow axis of the λ/4 plate, so that the LCD can have a smaller thickness and its fabrication cost can be reduced while having better or the same characteristics than an LCD using both λ/2 and λ/4 plates. In addition, in an ECB mode backlit LCD, transmittance, contrast ratio, and viewing angles can be enhanced by attaching both the λ/4 or λ/2 plate and allowing the absorption axis of the polarizer and the slow axis of the λ/4 and λ/2 plates to have predetermined angle relationships.

Claims (33)

1. A color filter display panel comprising:

a substrate comprising color filters;

a λ/4 plate formed on an outer side of the substrate and having a slow axis; and

a polarizer attached on an outer side of the λ/4 plate and having an absorption axis,

wherein the slow axis of the λ/4 plate is at 147±10 degrees with respect to a reference direction and the absorption axis of the polarizer is at 15±10 degrees with respect to the reference direction,

wherein the color filter display panel comprises a transmitting region and a reflecting region, and

wherein the λ/4 plate is disposed in the transmitting region and the reflecting region.

2. The display panel of claim 1 , wherein the λ/4 plate has a phase difference value of 155±20 nm when a wavelength of light passing through the λ/4 plate is 550 nm.

3. The display panel of claim 1 , wherein the substrate, the λ/4 plate, and the polarizer are attached to each other by an adhesive.

4. The display panel of claim 1 , wherein the λ/4 plate is coated on a lower surface of the polarizer.

5. The display panel of claim 4 , wherein the λ/4 plate is hardened with an alignment layer and a liquid crystal layer on the lower surface of the polarizer.

6. The display panel of claim 1 , further comprising a passivation layer formed on an outer side of the polarizer through hard coating or an anti-reflective treatment.

7. The display panel of claim 1 , wherein a λ/2 plate is excluded from the display panel to reduce a thickness of the display panel.

8. A liquid crystal display comprising a color filter display panel, a thin film transistor array panel, a liquid crystal formed therebetween, a transmitting region and a reflecting region,

wherein the color filter display panel comprises:

a first substrate comprising color filters;

a first λ/4 plate formed on an upper side of the first substrate and having a slow axis; and

a first polarizer attached on an upper side of the first λ/4 plate and having an absorption axis,

wherein the slow axis of the first λ/4 plate is at 147±10 degrees with respect to a reference direction, and the absorption axis of the first polarizer is at 15±10 degrees with respect to the reference direction, and

wherein the thin film transistor array panel comprises:

a second substrate comprising thin film transistors;

a second λ/4 plate formed on a lower side of the second substrate and having a slow axis; and

a second polarizer attached on a lower side of the second λ/4 plate and having an absorption axis,

wherein the slow axis of the second λ/4 plate is at 66±10 degrees with respect to the reference direction and the absorption axis of the second polarizer is at 105±10 degrees with respect to the reference direction,

wherein the first λ/4 plate and the second λ/4 plate are disposed in the transmitting region and the reflecting region.

9. The liquid crystal display of claim 8 , wherein the first λ/4 plate has a phase difference value of 155±20 nm when a wavelength of light passing through the first λ/4 plate is 550 nm, and the second λ/4 plate has a phase difference value of 135±20 nm when a wavelength of light passing through the second λ/4 plate is 550 nm.

10. The liquid crystal display of claim 8 , wherein the first substrate, the first λ/4 plate, and the first polarizer are attached to each other by an adhesive, and the second substrate, the second λ/4 plate, and the second polarizer are also attached to each other by an adhesive.

11. The liquid crystal display of claim 8 , wherein the first and second λ/4 plates are coated on the first and second polarizers, respectively.

12. The liquid crystal display of claim 11 , wherein the first and second λ/4 plates are hardened with an alignment layer and a liquid crystal layer on the first and second polarizers, respectively.

13. The liquid crystal display of claim 8 , further comprising:

first and second passivation layers formed on outer sides of the first and second polarizers through hard coating or an anti-reflective treatment.

14. The liquid crystal display of claim 8 , wherein a viewing angle of the liquid crystal formed between the color filter display panel and the thin film transistor array panel is ±40 degrees from a one o'clock direction.

15. The liquid crystal display of claim 8 , wherein a λ/2 plate is excluded from the color filter display panel and from the thin film transistor array panel to reduce a thickness of the liquid crystal display, and angles of the slow axes and the absorption axes maintain luminance and viewing angle characteristics of the liquid crystal display.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 21, 2012
From: SAMSUNG ELECTRONICS CO., LTD.
To: SAMSUNG DISPLAY CO., LTD.
Reel/Frame 029019/0139 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 14, 2006
From: KIM, SANG-WOO; LEE, CHEONG-HAENG; PARK, WON-SANG; CHANG, YOUNG-JOO; LEE, JUN-YOUNG; KANG, SUNG-WOOK; LEE, JAE-YOUNG; YUN, HAE-YOUNG; LIM, JAE-IK; LEE, SEUNG-KYU; SHIM, CHANG-WOO; YEO, YONG-SUK; CHOI, JI-YOUN
To: SAMSUNG ELECTRONICS CO., LTD.
Reel/Frame 018317/0419 →