Lighting device and display device provided with the same

• US 7,582,906 B2
• Filed: 03/08/2007
• Issued: 09/01/2009
• Est. Priority Date: 03/09/2006
• Status: Active Grant

• Current Assignee: Dawncrest IP LLC (IP Edge LLC)
• Original Assignee: Seiko Instruments Incorporated (Seiko Group)
• Inventors: Kurihara, Makoto
• Primary Examiner(s): Dang, Phuc T
• Application Number:
  US11/715,682
• Publication Number:
  US 20070210326A1
• Time in Patent Office: 908 Days
• Field of Search: 257/79, 257/88, 257/98, 257/99, 257/100, 257/E51.018, 257/E51.002, 257/E33.001, 257/E33.077, 362/293, 362/297, 362/304, 362/346
• US Class Current: 257/79
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48464 the other connecting portion not on the bonding area also being a ball bond, i.e. ball-to-ball
• 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 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body

Abstract

A lighting device surface-emits light from a light emitting surface of a light emitting element and guides the emitted light using a light guide member. The lighting device has a first wavelength conversion member for converting light emitted from the light emitting device into light having a first peak wavelength and a second wavelength conversion member for converting light emitted from the light emitting device into light having a wavelength shorter than the first peak wavelength. The first wavelength conversion member is provided between the light emitting element and the light guide member and is contained in a resin potting the light emitting element. A film has a layer containing the second wavelength conversion member. The film is provided on a light emitting surface side of the light guide member.

Claims

1. A lighting device that surface-emits light from a light emitting surface of a light emitting element and that guides the emitted light using a light guide member, the lighting device comprising:

a first wavelength conversion member provided between the light emitting element and the light guide member for converting light emitted from the light emitting device into light having a first peak wavelength, the first wavelength conversion member being contained in a resin potting the light emitting element;

a second wavelength conversion member for converting light emitted from the light emitting device into light having a wavelength shorter than the first peak wavelength; and

a film having a layer containing the second wavelength conversion member, the film being provided on a light emitting surface side of the light guide member.

3. A lighting device according to claim 1;

further comprising a resin layer in which transparent beads of one of acrylic and silica are dispersed, the resin layer being provided on the light emitting side with respect to the second wavelength conversion member.

4. A lighting device according to claim 1;

wherein the film layer contains transparent beads of one of acrylic and silica dispersed therein.

6. A lighting device according to claim 1;

wherein the film layer comprises an adhesive layer, and the film is obtained by laminating the second wavelength conversion member with a pair of films through the adhesive layer.

7. A lighting device according to claim 6;

wherein the adhesive layer is provided on a peripheral portion of the film and comprises an area which is free of the second wavelength conversion member.

8. A lighting device according to claim 7;

wherein the film is tucked in so that the area free of the second wavelength conversion member is located outside an optical path of light emitted from the light emitting element.

9. A lighting device according to claim 7;

wherein the area free of the second wavelength conversion member is provided with a reflecting layer.

10. A lighting device according to claim 8;

wherein the film is tucked in so that the film covers the light emitting element; and

wherein the film is arranged such that a light emitting surface thereof is oriented in any direction other than an orthogonal direction and a parallel direction with respect to an incident direction of light from the light emitting element.

11. A lighting device according to claim 1;

further comprising transparent lenses in a dorm shape which are arranged in a matrix, the lenses being provided outside the film layer so that the lenses are close to a light exiting side.

12. A lighting device according to claim 1;

further comprising transparent lenses in an elongated dorm shape which are arranged in stripes, the lenses being provided outside the film layer so that the lenses are close to a light exiting side.

13. A lighting device according to claim 1;

wherein the first wavelength conversion member comprises a red phosphor for converting light emitted from the light emitting element into red light through excitation of the light; and

wherein the second wavelength conversion member comprises a green phosphor for converting light emitted from the light emitting element into green light through excitation of the light.

14. A lighting device according to claim 13;

further comprising one of a second red phosphor and a yellow phosphor which converts light emitted from the light emitting element into yellow light through excitation of the light, the one of the second red phosphor and the yellow phosphor being provided between the red phosphor and the green phosphor.

15. A lighting device according to claim 1;

wherein the first wavelength conversion member comprises a red phosphor for converting light emitted from the light emitting element into red light through excitation of the light;

wherein the second wavelength conversion member comprises a green phosphor for converting light emitted from the light emitting element into green light through excitation of the light; and

wherein the film is provided thereon with one of a second red phosphor and a yellow phosphor which converts light emitted from the light emitting element into yellow light through excitation of the light.

17. A lighting device according to claim 1;

wherein the second wavelength conversion member is contained in the light guide member.

18. A lighting device according to claim 1;

wherein the second wavelength conversion member is provided on a light emitting surface side of the light guide member.

19. A lighting device according to claim 1;

wherein the first and second wavelength conversion members are provided in an optical path between the light emitting element and a light emitting surface of the lighting device; and

wherein the first and second wavelength conversion members are arranged in an order such that the first and second peak wavelengths decrease as a distance between the light emitting element and each of the first and second wavelength conversion members increases.

2. A lighting device that surface-emits light from a light emitting surface of a light emitting element and that guides the emitted light using a light guide member, the lighting device comprising:

a first wavelength conversion member for converting light emitted from the light emitting device into light having a first peak wavelength;

a second wavelength conversion member for converting light emitted from the light emitting device into light having a wavelength shorter than the first peak wavelength; and

a film provided on a light emitting surface side of the light guide member, the film having a first layer containing the first wavelength conversion member and a second layer containing the second wavelength conversion member.

20. A lighting device according to claim 2;

wherein the first and second wavelength conversion members are provided in an optical path between the light emitting element and a light emitting surface of the lighting device; and

wherein the first and second wavelength conversion members are arranged in an order such that the first and second peak wavelengths decrease as a distance between the light emitting element and each of the first and second wavelength conversion members increases.

5. A lighting device that surface-emits light from a light emitting surface of a light emitting element and that guides the emitted light using a light guide member, the lighting device comprising:

a first wavelength conversion member for converting light emitted from the light emitting device into light having a first peak wavelength;

a second wavelength conversion member for converting light emitted from the light emitting device into light having a wavelength shorter than the first peak wavelength; and

a film provided between the light emitting element and the light guide member, the film having a first layer containing the first wavelength conversion member and a second layer containing the second wavelength conversion member.

21. A lighting device according to claim 5;

wherein the first and second wavelength conversion members are provided in an optical path between the light emitting element and a light emitting surface of the lighting device; and

wherein the first and second wavelength conversion members are arranged in an order such that the first and second peak wavelengths decrease as a distance between the light emitting element and each of the first and second wavelength conversion members increases.

16. A display device in which a display element of a non-self light emission type is illuminated by using light emitted from a light emitting element and guided by a light guide member, the display device comprising:

a first wavelength conversion member for converting light emitted from the light emitting element into light having a first peak wavelength through excitation of the light, the first wavelength conversion member being contained in a resin potting the light emitting element;

a second wavelength conversion member for converting light emitted from the light emitting element into light having a wavelength shorter than the first peak wavelength; and

a film having a layer containing the second wavelength conversion member, the film being provided on a light emitting surface side of the light guide member.

22. A display device according to claim 16;

wherein the first and second wavelength conversion members are provided in an optical path between the light emitting element and the display element in a manner that the first wavelength conversion member and the second wavelength conversion member are separated from each other; and

wherein the first wavelength conversion member is arranged such that a distance between the first wavelength conversion member and the light emitting element is shorter than a distance between the second wavelength conversion member and the light emitting element.