Backlight apparatus having ventilating holes for liquid crystal display

• US 5,283,674 A
• Filed: 09/30/1992
• Issued: 02/01/1994
• Est. Priority Date: 09/30/1991
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Etoh, Arifumi, Ide, Heihachi, Hanaoka, Shunsuke
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): MAI, HUY KIM
• Application Number:
  US07/954,340
• Time in Patent Office: 489 Days
• Field of Search: 359/48, 359/49, 359/50, 362/217, 362/218, 362/294, 362/296, 362/297
• US Class Current: 349/67
• CPC Class Codes: F21V 19/0095 of U-shaped tubular light sources, e.g. compact fluorescent tubes
• CPC Class Codes: F21V 29/505 of reflectors
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21V 7/00 Reflectors for light sources characterised by cooling arrangements F21V29/505
• CPC Class Codes: F21Y 2103/37 U-shaped
• CPC Class Codes: G02F 1/133604 with lamps
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity
• CPC Class Codes: G02F 1/133628 with cooling means
• CPC Class Codes: H01J 61/325 U-shaped lamps

Abstract

A liquid crystal display apparatus which prevents illumination of light by non-uniform brightness from a fluorescent lamp employed for the backlight illumination which is caused by mercury enclosed in the fluorescent tube being deposited on the inner surface of the tube of the fluorescent lamp. The liquid crystal display apparatus comprises a liquid crystal display panel, a backlight apparatus including a fluorescent lamp disposed on the rear face side of the liquid crystal display panel for directing illuminating backlight upon the liquid crystal display panel, and a reflecting plate disposed remote from the liquid crystal display panel with respect to the fluorescent lamp. The reflecting plate has a plurality of ventilating holes formed at portions of a recessed portion thereof opposing to an outer periphery of the fluorescent lamp.

Claims

1. A liquid crystal display apparatus comprising:

a liquid crystal display panel;

a backlight apparatus including a fluorescent lamp disposed on the rear face side of said liquid crystal display panel for illuminating backlight therefrom upon said liquid crystal display panel; and

a reflecting plate disposed remote from said liquid crystal display panel with respect to said fluorescent lamp and having a plurality of ventilating holes formed at portions thereof opposing to an outer periphery of said fluorescent lamp, said plurality of ventilating holes being of a width less than a diameter of said fluorescent lamp to restrict deposits inside said fluorescent lamp to an area less than a diameter of said fluorescent lamp.

2. A liquid crystal display apparatus according to claim 1, wherein said width is considerably smaller than the diameter of said fluorescent lamp and said ventilation holes are of a length less than a length of said fluorescent lamp.

3. A liquid crystal display apparatus according to claim 1, wherein said reflecting plate has a recessed portion formed thereon in which said fluorescent lamp is accommodated, and said ventilating holes are formed at the bottom of said recessed portion of said reflecting plate.

4. A liquid crystal display apparatus according to claim 1, wherein said fluorescent lamp has a generally U-shaped profile, and said ventilating holes are formed successively along the U-shape of said fluorescent lamp.