Shielded reflective light-emitting diode

• US 6,886,962 B2
• Filed: 06/26/2002
• Issued: 05/03/2005
• Est. Priority Date: 06/27/2001
• Status: Expired due to Fees

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Suehiro, Yoshinobu
• Primary Examiner(s): Husar, Stephen
• Assistant Examiner(s): Zeade, Bertrand
• Application Number:
  US10/179,377
• Publication Number:
  US 20030002281A1
• Time in Patent Office: 1,042 Days
• Field of Search: 362/241, 362/235, 362/240, 362/249, 362/248, 362/341, 362/347, 362/800, 362/301, 362/303, 362/343, 362/305, 362/354, 313/500, 313/512
• US Class Current: 362/241
• 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 comprises at least one optical opening portion, and

wherein said reflecting mirror comprises a cylindrical surface shape in which light emitted from said light source and reflected by said reflecting mirror is condensed linearly such so that the linearly condensed light is radiated out through said at least one optical opening portion of said light-shielding member.

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

3. The 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. The 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. The shielded reflective light-emitting diode according to claim 4, wherein said light-radiating surface comprises a convex lens.

6. The shielded reflective light-emitting diode according to claim 4, wherein said light-radiating surface comprises a curved cylindrical surface shaped such 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. The shielded reflective light-emitting diode according to claim 1, wherein said at least one light source comprises a plurality of light sources which are arranged along an axial direction of said reflecting mirror shaped like a cylindrical surface.

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

9. The shielded reflective light-emitting diode according to claim 8, wherein said at least one light source comprises 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.

10. The shielded reflective light-emitting diode according to claim 1, further comprising:

a substrate portion for mounting said light source on said light-shielding member, said substrate portion comprising a black side on which said light source is mounted.

11. The shielded reflective light-emitting diode according to claim 10, further comprising:

a black spacer for changing a height of said substrate portion.

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

13. A shielded reflective device comprising:

a substrate comprising a black side;

a light source portion including a light-emitting portion, and mounted on said black side of said substrate;

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

a light-shielding member including an optical opening portion.

14. The shielded reflective device according to claim 13, further comprising:

a black spacer for changing a height of said substrate portion.

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 light-shielding member comprising a film shape and including an optical opening portion.

16. A light source comprising:

a light-emitting element formed on a substrate; and

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

wherein a portion of said substrate on which said light-emitting element is mounted comprises a heat-dissipation conductive member which extends to a rear surface of said substrate.

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

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

19. The tight source according to claim 17, wherein a difference between a width of said substrate and a diameter of said convex lens is no greater than 1 mm.

20. A shielded reflective device comprising:

a light-emitting element;

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

a substrate;

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

a light-shielding member including an optical opening portion,

wherein a portion of said substrate on which said light-emitting element is mounted comprises a heat-dissipation conductive member which extends to a rear surface of said substrate,

wherein said light-transmissive material forms a convex lens, and

wherein a difference between a width of said substrate and a diameter of said convex lens is no greater than 1 mm.