Backlight device and liquid crystal display having conductive film on electromagnetic shield or diffuser between fluorescent tubes and display

• US 5,333,073 A
• Filed: 12/29/1992
• Issued: 07/26/1994
• Est. Priority Date: 01/09/1992
• Status: Expired due to Term

• Current Assignee: Gold Charm Limited (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Suzuki, Mitsuhiro
• Primary Examiner(s): Gross, Anita P.
• Application Number:
  US07/997,939
• Time in Patent Office: 574 Days
• Field of Search: 359/50, 359/69, 359/83
• US Class Current: 349/59
• CPC Class Codes: F21V 25/00 Safety devices structurally associated with lighting devices gas- tight or water-tight arrangements F21V31/00; in general F16P; protective circuit arrangements per se H02H7/00
• CPC Class Codes: G02F 1/133334 Electromagnetic shields
• CPC Class Codes: G02F 1/133604 with lamps
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity

Abstract

A liquid crystal display equipment comprising a liquid crystal display panel for displaying therein characters or an image, a backlight device serving as an auxiliary device to finely display the characters or image in the display panel by irradiating a light from the back of the liquid crystal display panel, and a sheet of light diffusion plate mounted between the liquid crystal display panel and the backlight device and making a uniform illumination plane for the display panel by diffusing the light through itself. The backlight device comprises a transparent conductive film mounted in the vicinity of a plurality of fluorescent lamps arranged in parallel relationship to one another on the back side of the light diffusion plate so as to act as a backlight source of the backlight device.

Claims

1. A backlight device comprising a plurality of fluorescent lamps arranged in parallel relationship to one another on a back side of a liquid crystal display panel as a backlight of said display panel, an electromagnetic shielding means mounted between the fluorescent lamps and the display panel, two transparent conductive films, one on each side of the electromagnetic shielding means, and a light diffusion plate between the display panel and the electromagnetic shielding means for diffusing the light irradiated from said fluorescent lamps to the liquid crystal display panel.

2. A backlight device comprising a plurality of fluorescent lamps arranged in parallel relationship to one another on a back side of a liquid crystal display panel as a backlight of said display panel, a light diffusion plate between the display and the fluorescent lamps for diffusing the light irradiated from said fluorescent lamps to the liquid crystal display panel, and two transparent conductive films, one on each side of the diffusion plate.

3. A backlight device comprising a plurality of fluorescent lamps arranged in parallel relationship to one another on a back side of a liquid crystal display panel as a backlight of said display panel, an electromagnetic shielding means mounted between the fluorescent lamps and the display panel, and a light diffusion plate between the display panel and the electromagnetic shielding means for diffusing the light irradiated from said fluorescent lamps to the liquid crystal display panel, said electromagnetic shielding means comprising a transparent polyester film, a transparent conductive film comprising indium tin oxide formed on a surface of the electromagnetic shielding means, an aluminum pattern formed on a surface of said indium tin oxide film, and a thin over-coating layer formed on and over surfaces of said aluminum pattern and said indium tin oxide film, wherein said aluminum pattern is so formed as to border all edge portions of said indium tin oxide film.

4. A backlight device as set forth in claim 3, wherein said aluminum pattern is formed at such portions of said indium tin oxide film as correspond to said fluorescent lamps.

5. A backlight device as set forth in claim 4, wherein said aluminum pattern has a great number of light transmitting holes each of whose size is adjusted in proportion to the degree of luminous intensity that passes therethrough.

6. A backlight device comprising a plurality of fluorescent lamps arranged in parallel relationship to one another on a back side of a liquid crystal display panel as a backlight of said display panel, an electromagnetic shielding means mounted between the fluorescent lamps and the display panel, and a light diffusion plate between the display panel and the electromagnetic shielding means for diffusing the light irradiated from said fluorescent lamps to the liquid crystal display panel, said electromagnetic shielding means comprising a transparent polyester film, a transparent conductive film comprising indium tin oxide formed on each surface of the electromagnetic shielding means, an aluminum pattern formed on a surface of each said indium tin oxide film, and a thin over-coating layer formed on and over surfaces of each of said aluminum pattern and said indium tin oxide films, wherein said aluminum patterns are so formed as to border all edge portions of said indium tin oxide films.

7. An electromagnetic shielding member comprising a transparent polyester film, a transparent conductive film formed on and over said polyester film, and an aluminum pattern formed on a surface of said conductive film, said aluminum pattern being so formed as to border all edge surfaces of said transparent conductive film.