Backlight device and a backlighting element

• US 7,038,391 B2
• Filed: 06/18/2003
• Issued: 05/02/2006
• Est. Priority Date: 08/26/1998
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Tsumura, Toshiyuki
• Primary Examiner(s): VU, DAVID HUNG
• Application Number:
  US10/464,218
• Publication Number:
  US 20030209991A1
• Time in Patent Office: 1,049 Days
• Field of Search: 315/169.1, 315/169.3, 315/225, 315/136, 315/132
• US Class Current: 315/169.1
• CPC Class Codes: G09G 2310/0237 Switching ON and OFF the backlight within one frame
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2330/06 Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336

Abstract

A backlighting element 13 includes an EL panel for illuminating the back of a display unit 11, to thereby provide a good viewing. A control unit 16 sends an instruction to a backlight driver 14, and intermittently drives the backlighting element 13 at appropriate timings, or temporarily stops the driving of the backlighting element 13 in synchronism with operation timings of a radio processing unit 17. The radio processing unit is adversely affected by noise generated when the backlighting element is operated. A light storage member is provided on the backlighting element 13 or in its vicinity. With provision of the light storage member, the lighting time of the backlighting element is reduced. When the backlighting element is lit off, the user is not put to inconvenience.

Claims

1. A backlight device comprising:

a backlighting element for illuminating the back of visually presenting means of a device; and

drive control means for temporarily stopping the driving of said backlighting element when a portion of said device is being adversely affected by noise generated by operation of said backlighting element, wherein said drive control means is operated in synchronism with operation timings of the device.

2. The backlight device according to claim 1, further comprising:

a light storage member capable of storing backlight from said light emitting means of said backlighting element or natural light to spontaneously emit light.

3. A mobile communication device comprising a backlight device, the backlight device comprising:

a backlighting element with an EL panel providing a light emitting means for illuminating the back of a visually presenting means;

at least one light emitting section making up the backlighting element; and

upper and lower electrodes forming each of said light emitting sections;

wherein

at least one of said upper and lower electrodes form the light emitting section of said backlighting element such that said light emitting section is disposed to occupy a portion that is less than a whole part of a viewing area of said backlighting element defined by a configuration of said light emitting means in said EL panel, and wherein

said light emitting section is further disposed such that another portion that is less than a whole part of the viewing area is not occupied by any light emitting section, and further wherein

said backlight device is adapted such that when the light emitting means is illuminating said back, a viewer is given the impression that said another portion is also being illuminated.

4. The mobile communication device according to claim 3, wherein said light emitting section takes a form selected from a group of a lattice, a stripe and a slant lattice.

5. The mobile communication device according to claim 3, wherein said visually presenting means comprises a display unit including a liquid crystal panel and wherein said light emitting section is formed corresponding to a shape of display lines of said liquid crystal display panel or display units consisting of display characters.

6. The mobile communication device according to claim 3, wherein

said visually presenting means comprises a display unit including a liquid crystal panel and wherein

said light emitting section is divided into a plurality of light emitting segments corresponding to display lines of said liquid crystal display panel or display units consisting of display characters, and further wherein

said plurality of light emitting segments are selectively driven.

7. The mobile communication device according to claim 3 further comprising:

a light diffusing means for diffusing light emitted from said light emitting section.

8. The mobile communication device according to claim 7, wherein said light diffusing means is formed by interposing a sheet or plate member having a light diffusing function between said backlighting element and an illuminated member, by coating the surface of said backlighting element with light diffusing material, or by coupling an optional member having light diffusing function to said backlighting element or an illuminated member.

9. The mobile communication device according to claim 7, further comprising:

a light storage member capable of storing backlight from said light emitting means of said backlighting element or natural light to spontaneously emit light.

10. The mobile communication device according to claim 9, wherein said light storage means is formed by interposing a sheet or plate member with light storage material between said backlighting element and an illuminated member, by coating the surface of said backlighting element with light storage material, or by use of said backlighting element with light storage material.

11. The mobile communication according to claim 7, wherein:

said visually presenting means is a liquid crystal panel constituting a display unit of a device,

said light emitting section of said backlighting element is divided into a plurality of segments corresponding to display lines of said liquid crystal display panel or display units consisting of display characters, and

said backlighting device comprises drive control means for selectively driving said plurality of segments of said light emitting section to locally light on and off said light emitting section.