Method for illuminating liquid crystal display device, a back-light assembly for performing the same, and a liquid crystal display device using the same

• US 20090015752A1
• Filed: 05/22/2008
• Published: 01/15/2009
• Est. Priority Date: 06/07/2000
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Ik-Soo Lee, Jeong-Hwan Lee, Jong-Ho Won, Kyu-Seok Kim
• Inventors: Lee, Jeong-Hwan, Kim, Kyu-Seok, Won, Jong-Ho, Lee, Ik-Soo
• Granted Patent: US 7,710,513 B2
• Time in Patent Office: Days
• US Class Current: 349/64
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side

Abstract

A method for illuminating a liquid crystal display device, a back-light assembly for performing the same and a liquid crystal display device using the same can improve the front luminance and production yield. Lights from a lamp is incident to a LCD panel side, which are then primarily diffused for a uniformity of the luminous flux of the incident lights. The luminous flux of the primarily diffused lights is condensed with respect to a first orientation component on a plane in parallel with the LCD panel, and then partially and secondarily diffused for extending a view angle of pixels of the LCD panel. After the luminous flux of the secondarily diffused lights is condensed with respect to a second orientation component perpendicular to the first orientation on the parallel plane, the condensed lights are illuminated onto the LCD panel. A diffusion sheet for secondarily diffusing the luminous flux and a condensing sheet for condensing the second orientation component are formed by a single sheet to reduce the manufacturing process of the liquid crystal display device. Also, a defect produced from respective sheets is minimized to enhance the yield.

Claims

1-17. -17. (canceled)

18. A liquid crystal display (LCD), comprising:

an LCD panel;

a light source;

a diffuser formed on the light source; and

a condenser formed between the LCD panel and the diffuser,

wherein the diffuser comprises a plurality of beads formed on a surface of the diffuser adjacent to the light source distributed to have a higher density than a plurality of beads formed on a surface of the diffuser adjacent to the condenser so that the surface of the diffuser adjacent to the condenser has a haze value that is larger than that of the surface of the diffuser adjacent to the light source.

19. A liquid crystal display (LCD), comprising:

an LCD panel;

a light source;

a diffuser formed between the LCD panel and the light source; and

a condenser formed between the LCD panel and the diffuser,

wherein the diffuser comprises a plurality of beads formed on at least a surface of the diffuser adjacent to the light source and a surface of the diffuser adjacent to the condenser, and

the plurality of beads are distributed to have a higher density at the surface of the diffuser adjacent to the condenser than that at the surface of the diffuser adjacent to the light source.

20. A liquid crystal display (LCD), comprising:

an LCD panel;

a light source;

a diffuser formed between the LCD panel and the light source;

a condenser formed between the LCD panel and the diffuser; and

a high luminance condensing sheet formed between the LCD panel and the condenser,

wherein the diffuser comprises a plurality of beads formed on a surface of the diffuser adjacent to the light source distributed to have a higher density than a plurality of beads formed on a surface of the diffuser adjacent to the condenser so that the surface of the diffuser adjacent to the condenser has a haze value that is larger than that of the surface of the diffuser adjacent to the light source.

21. A liquid crystal display (LCD), comprising:

an LCD panel;

a light source;

a diffuser formed between the LCD panel and the light source;

a condenser formed between the LCD panel and the diffuser; and

a high luminance condensing sheet formed between the LCD panel and the condenser,

wherein the high luminance condensing sheet comprises a transparent sheet having a predetermined thickness, a diffusion layer formed at the lower surface of the transparent sheet, and a condensing layer formed at the upper surface of the transparent sheet.