Liquid crystal display apparatus

• US 20070085944A1
• Filed: 10/16/2006
• Published: 04/19/2007
• Est. Priority Date: 10/17/2005
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Kaneko, Hiroki, Tanaka, Toshiaki, Hiyama, Ikuo
• Granted Patent: US 7,567,317 B2
• Time in Patent Office: Days
• US Class Current: 349/69
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133612 Electrical details
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16245 the item being metallic
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A cold-cathode tube has hitherto been used as a backlight for supplying illumination to a liquid crystal television but recently, light emitting diode pieces have been used for a backlight of a large-size liquid crystal television. For the purpose of improving the emission efficiency, flip chip mounting of the light emitting diode piece is advantageous but the mounting yield is restricted by the piece size, electrode structure and wire pattern structure, facing situations having difficulties in realizing simplified mounting and reduction of costs of members. In a liquid crystal display apparatus having a liquid crystal panel, an optical system and a light source, the light source includes a light emitting element structure having positive and negative electrodes, at least one of them being plural, and wires mounted to the positive and negative electrodes through flip chip mounting by making electrical correspondence to individual regions of the positive and negative electrodes.

Claims

1. A liquid crystal display apparatus comprising:

a liquid crystal panel;

an optical system; and

a light source,

wherein said light source includes;

a light emitting element structure having positive and negative electrodes, at least one of them being plural, and wires mounted to said positive and negative electrodes by making electrical correspondence to individual regions of said positive and negative electrodes.

2. A liquid crystal display apparatus according to claim 1, wherein said light emitting element structure has a positive electrode constructed as mergence of singular positive electrodes of individual light emitting unit elements of minimum unit and a negative electrode constructed of mergence of singular negative electrodes of the individual light emitting unit elements of minimum unit, said light emitting unit elements of minimum unit being divisions of said light emitting element structure on the same substrate.

3. A liquid crystal display apparatus according to claim 2, wherein said light emitting element structure has the positive electrode constructed as mergence of a singular positive electrode of the individual light emitting unit elements of minimum unit and the negative electrode constructed as mergence of singular negative electrodes of said individual light emitting unit elements of minimum unit, whereby said light emitting element structure has a light intensity corresponding to the sum of light intensities of plural light emitting unit elements.

4. A liquid crystal display apparatus according to claim 2, wherein a plurality of light emitting unit elements of minimum unit having each a singular positive electrode and a singular negative electrode are mounted in parallel to corresponding wires.

5. A liquid crystal display apparatus according to claim 1, wherein said light source includes a substrate transparent to an emission wavelength of said light emitting element structure.

6. A liquid crystal display apparatus according to claim 2, wherein a plurality of said light emitting unit elements of minimum unit are mounted in series by means of said wires.

7. A liquid crystal display apparatus according to claim 2, wherein said light emitting unit element of minimum unit is arranged cyclically so that its positive electrode or negative electrode may be merged.

8. A liquid crystal display apparatus according to claim 7, wherein every two, three or four of said light emitting unit elements of minimum unit are arranged cyclically.

9. A liquid crystal display apparatus according to claim 2, wherein said wires are laid on a metallic substrate through an insulating layer and said light emitting element structure has a breakdown voltage of 1 kV or more.

10. A liquid crystal display apparatus according to claim 2, wherein said wires are laid on a ceramic substrate through an insulating layer and said light emitting element structure has a breakdown voltage of 1 kV or more.

11. A liquid display apparatus according to claim 2, wherein said light emitting unit element of minimum unit is a white light emitting element including a yellow fluorescent substance and a blue light emitting diode piece which are sealed with resin, a white light emitting element including green and red fluorescent substances and a blue light emitting diode piece which are sealed with resin or a white light emitting element including a three primary color light source of blue, green and red light emitting diode pieces which are sealed with resin.

12. A liquid crystal display apparatus according to claim 2, wherein said light source is used as a backlight of a liquid crystal display for a cell phone, personal computer or television.

13. A liquid crystal display apparatus according to claim 1, wherein said light emitting element structure is flip-chip mounted to said wires.

14. A liquid crystal display apparatus according to claim 2, wherein a plurality of light emitting unit elements of minimum unit each having a singular positive electrode and a singular negative electrode are connected in parallel to corresponding wires to form a parallel circuit.

21. The light source as recited in claim 1, wherein said light emitting element structure is wire-bonding mounted to said wires.

15. A light source comprising:

a substrate;

a plurality of wires laid on said substrate; and

a plurality of light emitting unit elements each having a positive electrode and a negative electrode which are connected to corresponding wires,

wherein said plurality of light emitting unit elements are formed in such a pattern that positive electrodes or negative electrodes may be merged every two or more or light emitting unit elements.

16. A light source according to claim 15, wherein said light emitting unit elements formed in pattern are connected to said wires in every two or more pattern-formed light emitting unit elements.

17. A light source according to claim 15, wherein said light emitting unit element is flip-chip mounted to said wires.

18. A light source according to claim 15, wherein said pattern-formed light emitting unit elements are connected in parallel with said wires and are also connected in series with said wires in every two or more pattern-formed light emitting unit elements.

19. A light source according to claim 15, wherein said pattern-formed light emitting unit element includes two, three or four light emitting diode pieces.

20. A liquid crystal display apparatus comprising:

the light source as recited in claim 15;

and

a liquid crystal panel.

22. The light source according to claim 15, wherein said light emitting unit element is wire-bonding mounted to said wires.