Liquid Crystal Display Apparatus

• US 20090066878A1
• Filed: 07/03/2008
• Published: 03/12/2009
• Est. Priority Date: 09/11/2007
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Abe, Fukuyasu, Ogiro, Kenji, Kaku, Nobuyuki
• Application Number:
  US12/167,335
• Publication Number:
  US 20090066878A1
• Time in Patent Office: Days
• US Class Current: 349/62
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• 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 1/133611 including means for improving the brightness uniformity

Abstract

A liquid crystal display apparatus, comprises: a liquid crystal display (3); and a plural numbers of light emitting diodes (7), as a directly underlying type backlight, which is disposed on a rear surface of the liquid crystal display, so as to irradiate lights upon said liquid crystal display, wherein a translucent light guidance member (5), which is provided at least corresponding to each one or more of the plural numbers of light emitting diodes, and the translucent light guidance member (5) is in a cylindrical configuration, and reflection surfaces are defined on each of outer wall surfaces (53) and inner wall surfaces (52) of the cylindrical light guidance member, so as to reflect the lights from the light emitting diodes upon those reflection surfaces, and thereby guiding them onto a side of the liquid crystal display by those reflection surfaces.

Claims

1. A liquid crystal display apparatus, comprising:

a liquid crystal display; and

a directly underlying type backlight, which is disposed on a rear surface of said liquid crystal display, so as to irradiate lights upon said liquid crystal display, wherein

said backlight is made of a group of plural numbers of light emitting diodes, and has

a translucent light guidance member, which is provided at least corresponding to each one or more of said plural numbers of light emitting diodes, wherein

said translucent light guidance member is in such cylindrical configuration, that it provides a light guiding portion in a direction perpendicular to a display surface of said liquid crystal display, and that a reflection surface is defined on each of outer wall surfaces and inner wall surfaces of said cylindrical light guidance member, whereby reflecting a light from said light emitting diode upon those reflection surfaces, and guiding it onto a side of said liquid crystal display by the light guidance member.

2. The liquid crystal display apparatus, as described in the claim 1, wherein said cylindrical light guidance member has a polygonal or circular cross-section, in parallel with the display surface of said liquid crystal display.

3. The liquid crystal display apparatus, as described in the claim 1, wherein

the inner wail surface and the outer wall surface of said light guidance member on the side of the liquid crystal display are built up with parallel wall surfaces having a predetermined length thereof, and

an end portion of the inner wall surface of said light guidance member on the side of said light emitting diode is located at a position near to the side of said liquid crystal display than an end portion of the outer wall surface of said light guidance member, on the side of said light emitting diode, and an inclination surface is defined between an end portion of the parallel wall surface of said inner wall surface on the side of said light emitting diode and an end portion side of the parallel wall surface of the outer wall surface on the side of said light emitting diode.

4. The liquid crystal display apparatus, as described in the claim 1, wherein

on a surface opposite the side of said light guidance member on the side of said liquid crystal display is formed a fine concave/convex light diffusion pattern for diffusing the light of said light emitting diode to emit it therefrom.

5. The liquid crystal display apparatus, as described in the claim 2, wherein

on a surface opposite the side of said light guidance member on the side of said liquid crystal display is formed a fine concave/convex light diffusion pattern for diffusing the light of said light emitting diode to emit it therefrom.

6. The liquid crystal display apparatus, as described in the claim 3, wherein

on a surface opposite the side of said light guidance member on the side of said liquid crystal display is formed a fine concave/convex light diffusion pattern for diffusing the light of said light emitting diode to emit it therefrom.

7. The liquid crystal display apparatus, as described in the claim 1, wherein a light diffusion member is disposed between said light guidance member and said liquid crystal display, for diffusing lights from the group of said light emitting diodes and lights guided by said light guidance member thereon.

8. The liquid crystal display apparatus, as described in the claim 2, wherein a light diffusion member is disposed between said light guidance member and said liquid crystal display, for diffusing lights from the group of said light emitting diodes and lights guided by said light guidance member thereon.

9. The liquid crystal display apparatus, as described in the claim 3, wherein a light diffusion member is disposed between said light guidance member and said liquid crystal display, for diffusing lights from the group of said light emitting diodes and lights guided by said light guidance member thereon.

10. The liquid crystal display apparatus, as described in the claim 4, wherein a light diffusion member is disposed between said light guidance member and said liquid crystal display, for diffusing lights from the group of said light emitting diodes and lights guided by said light guidance member thereon.

11. The liquid crystal display apparatus, as described in the claim 5, wherein a light diffusion member is disposed between said light guidance member and said liquid crystal display, for diffusing lights from the group of said light emitting diodes and lights guided by said light guidance member thereon.

12. The liquid crystal display apparatus, as described in the claim 6, wherein a light diffusion member is disposed between said light guidance member and said liquid crystal display, for diffusing lights from the group of said light emitting diodes and lights guided by said light guidance member thereon.

13. The liquid crystal display apparatus, as described in the claim 4, wherein upon the inclination surface of said light guidance member is formed a prism pattern.

14. The liquid crystal display apparatus, as described in the claim 5, wherein upon the inclination surface of said light guidance member is formed a prism pattern.

15. The liquid crystal display apparatus, as described in the claim 6, wherein upon the inclination surface of said light guidance member is formed a prism pattern.