Shielded reflective light-emitting diode

• US 20030002281A1
• Filed: 06/26/2002
• Published: 01/02/2003
• Est. Priority Date: 06/27/2001
• Status: Active Grant

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Suehiro, Yoshinobu
• Granted Patent: US 6,886,962 B2
• Time in Patent Office: Days
• US Class Current: 362/245
• CPC Class Codes: F21V 11/12 of slot type
• CPC Class Codes: F21V 13/10 the elements being reflectors and screens
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2113/00 Combination of light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G09F 9/33 being semiconductor devices, e.g. diodes
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• 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 2924/00014 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 2924/3025 Electromagnetic shielding
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/64 Heat extraction or cooling elements
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

In a shielded reflective LED, each of light sources can be surface-mounted substantially without being influenced by heat distortion based on the difference in thermal expansion coefficient between resin and metal because the light source is so small-sized that only one light-emitting element is sealed with a resin. Moreover, variations in luminous intensity and chromaticity of each of light-emitting elements used in three-color light sources can be examined in advance. Hence, well-matched three-color light sources can be mounted in combination so that display unevenness of a full color display can be reduced greatly. Further, the surface of the substrate portion on which the light source is fixed is silk-screen-printed in black. Hence, external light which enters the device through the optical opening portion when the device is turned off is reflected by the reflecting mirror and absorbed to the surface of the substrate portion. As a result, pseudo-lighting in which external light is radiated out again through the optical opening portion can be prevented thoroughly, so that contrast between light when the device is turned on and light when the device is turned off can be made high.

Claims

1. A shielded reflective light-emitting diode comprising:

at least one light source including at least one light-emitting element;

a reflecting mirror provided opposite to said light source; and

a light-shielding member for limiting external light incident on said reflecting mirror,

wherein said light-shielding member has an optical opening portion, and

said reflecting mirror is shaped like a cylindrical surface in which light emitted from said light source and reflected by said reflecting mirror is condensed linearly so that the linearly condensed light is radiated out through said optical opening portion of said light-shielding member.

2. A shielded reflective light-emitting diode according to claim 1, wherein said optical opening portion has a size and a shape equivalent to those of an area of light condensed by said reflecting mirror shaped like a cylindrical surface.

3. A shielded reflective light-emitting diode according to claim 1, wherein said light source further includes a concave reflecting mirror provided around said light-emitting element.

4. A shielded reflective light-emitting diode according to claim 3, wherein said light source further includes a light-transmissive material with which said light-emitting element and said concave reflecting mirror are sealed and which forms a light-radiating surface on a light-emitting surface side of said light-emitting element.

5. A shielded reflective light-emitting diode according to claim 4, wherein said light-radiating surface is constituted by a convex lens.

6. A shielded reflective light-emitting diode according to claim 4, wherein said light-radiating surface is a curved cylindrical surface shaped so that a top portion of an ellipsoidal convex lens with a major diameter direction facing toward a direction substantially perpendicular to a lengthwise direction of said reflecting mirror shaped like a cylindrical surface is cut in said major diameter direction.

7. A shielded reflective light-emitting diode according to claim 1, wherein a plurality of light sources which are arranged along an axial direction of said reflecting mirror shaped like a cylindrical surface are used as said at least one light source.

8. A shielded reflective light-emitting diode according to claim 1, wherein a plurality of light sources which emit light in different colors respectively are used as said at least one light source.

9. A shielded reflective light-emitting diode according to claim 8, wherein a red light source having a red light-emitting element, a green light source having a green light-emitting element and a blue light source having a blue light-emitting element are used as said at least one light source.

10. A shielded reflective light-emitting diode according to claim 1, further comprising a substrate portion for mounting said light source on said light-shielding member, and a side of said substrate portion on which said light source is mounted is black.

11. A shielded reflective light-emitting diode according to claim 10, further comprising a spacer which is provided for changing a height of said substrate portion and which is black.

12. A shielded reflective light-emitting diode according to claim 1, wherein said light-shielding member is shaped like a film.

14. A shielded reflective device according to claim 13, further comprising a spacer which is provided for changing a height of said substrate portion and which is black.

17. A light source according to claim 16, wherein said light-transmissive material forms a convex lens.

18. A light source according to claim 16, wherein said substrate is shaped so that four corners of said substrate are cut.

19. A light source according to claim 17, wherein (width of said substrate−

diameter of said convex lens) ≦

1 mm is satisfied.

13. A shielded reflective device comprising:

a light source portion including a light-emitting portion;

a reflecting mirror provided opposite to a light-radiating side of said light source portion; and

a douser including an optical opening portion, wherein said shielded reflective device further comprises a substrate portion on which said light source portion is mounted, and

a side of said substrate portion on which said light source portion is mounted is black.

15. A shielded reflective device comprising:

a light source portion including a light-emitting portion;

a reflecting mirror provided opposite to a light-radiating side of said light source portion; and

a douser including an optical opening portion, wherein said douser is shaped like a film.

16. A light source comprising:

a light-emitting element;

a light-transmissive material with which said light-emitting element is sealed; and

a substrate,

wherein a portion of said substrate on which said light-emitting element is mounted is made of a heat-dissipation conductive member, and

said heat-dissipation conductive member reaches a rear surface of said substrate.

20. A shielded reflective device comprising:

a light-emitting element;

a light-transmissive material with which said light-emitting element is sealed; and

a substrate,

a reflecting mirror provided opposite to a light-radiating side of said light-emitting element; and

a douser including an optical opening portion,

wherein a portion of said substrate on which said light-emitting element is mounted is made of a heat-dissipation conductive member, and

said heat-dissipation conductive member reaches a rear surface of said substrate,

said light-transmissive material forms a convex lens, and

(width of said substrate−

diameter of said convex lens) ≦

1 mm is satisfied.