Light-emitting diode arrangement, optical recording device and method for the pulsed operation of at least one light-emitting diode

• US 8,482,663 B2
• Filed: 06/13/2005
• Issued: 07/09/2013
• Est. Priority Date: 06/30/2004
• Status: Expired due to Fees

• Current Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Farchtchian, Nadir, Kuhn, Gerhard, Sailer, Michael, Stich, Andreas, Kirchberger, Gnter, Rose, Monika
• Primary Examiner(s): CUTLER, ALBERT H
• Application Number:
  US11/630,742
• Publication Number:
  US 20080297644A1
• Time in Patent Office: 2,948 Days
• Field of Search: 348/370, 348/371, 315/241.P, 315/241.S, 362/249.02, 362/545, 362/555
• US Class Current: 348/371
• 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

Abstract

A light-emitting diode array is disclosed which has two light-emitting diodes which are connected in antiparallel with one another, and a power supply which is suitable for energizing the light-emitting diodes independently of one another in the forward direction. In addition, an optical recording apparatus and a method for the pulsed operation of a light-emitting diode are disclosed.

Claims

1. Light-emitting diode array comprising:

two light-emitting diodes which are connected in antiparallel with one another,

wherein a first of said light-emitting diodes is bonded to a first connecting part such that the first of said light-emitting diodes is in direct electrical contact with the first connecting part and placed in contact with a second connecting part via a first wire bonding contact and

wherein a second of said light-emitting diodes is bonded to the second connecting part such that the second of said light-emitting diodes is in direct electrical contact with the second connecting part and is placed in contact with the first connecting part by means of a second wire bonding contact; and

a device which is suitable for energizing the light-emitting diodes with current in alternating directions,

wherein the two light-emitting diodes differ in terms of their electrical power drain such that the light-emitting diodes form a mutual ESD protection,

wherein a luminescence-conversion material is provided which is suitable for at least partially converting the wavelength of the electromagnetic radiation which is emitted by the first of said light-emitting, diodes,

wherein the electromagnetic radiation of the first of said light-emitting diodes mixes with a wavelength-converted component of its radiation to form white light,

wherein the first of said light-emitting diodes is suitable for emitting electromagnetic radiation with a wavelength between 420 nm and 470 nm, and in which the luminescence-conversion material is suitable for converting part of this radiation into electromagnetic radiation with a wavelength between 530 nm and 580 nm,

wherein the light-emitting diodes are surrounded by a common sealing compound which contains the luminescence-conversion material, wherein the radiation emitted by the second of said light-emitting diodes passes through the sealing compound without being converted and the radiation emitted by the first of said light-emitting diodes is at least partially converted in terms of its wavelength by the luminescence-conversion material,

wherein at least one of the light-emitting diodes has a light-emitting diode chip, wherein all light-emitting diode chips are of a thin-film design, wherein each light-emitting diode chip contains an epitaxially grown stack of layers which comprises at least one active zone in which electromagnetic radiation is generated and a carrier, to which the epitaxially grown stack of layers is applied, wherein the epitaxially grown stack of layers is free of a growth substrate and a mirror layer is arranged between said carrier and said epitaxially grown stack of layers.

2. Light-emitting diode array according to claim 1, in which the device is suitable for energizing the light-emitting diodes for predefinable time periods with current with a predefinable direction and strength.

3. Light-emitting diode array according to claim 1, in which the device is a pulse-width-modulation circuit.

4. Light-emitting diode array according to claim 1, in which the light-emitting diodes are arranged in a common housing.

5. Light-emitting diode array according to claim 1, in which the second of the light-emitting diodes is suitable for emitting electromagnetic radiation in one of the following spectral ranges:

red, green, yellow.

6. Light-emitting diode array according to claim 5, in which the second of the light-emitting diodes is suitable for emitting electromagnetic radiation in the red spectral range with a wavelength between 600 nm and 750 nm.

7. Light-emitting diode array according to claim 1, in which at least one further light-emitting diode is connected in series with at least one of the light-emitting diodes.

8. Light-emitting diode array according to claim 1, which is provided as an illumination device in one of the following pieces of equipment:

interior lighting system for a motor vehicle, video camera, still camera.

9. Light-emitting diode array according to claim 1, having:

an optical detector which is suitable for detecting an electromagnetic radiation pulse of one of the light-emitting diodes which is reflected by an object, and

an evaluation circuit which is suitable for determining the distance between the object and the detector using the detector signal.

10. Optical recording apparatus, having a light-emitting diode array according to claim 1.

11. Optical recording apparatus according to claim 10, in which an optical detector is provided which is suitable for detecting an electromagnetic radiation pulse of one of the light-emitting diodes which is reflected by an object, and an evaluation circuit which is suitable for determining the distance between the object and the detector using the detector signal.

12. Optical recording apparatus according to claim 10, in which at least one of the light-emitting diodes is suitable for generating flash light with an illumination period of up to 500 ms.

13. Optical recording apparatus according to claim 12, in which the illumination intensity of the flash light can be set in a defined fashion.

14. Optical recording apparatus according to claim 10, in which at least one of the light-emitting diodes is suitable for lighting in a continuous operating mode.

15. Optical recording apparatus according to claim 10, in which a device is provided which is suitable for energizing at least one of the light-emitting diodes in synchronism with an image recording sequence which is controlled by the optical recording apparatus.

16. Optical recording apparatus according to claim 10, in which said apparatus is one of the following pieces of equipment:

mobile phone with a camera, digital camera, video camera.

17. A method for the pulsed operation of at least one light-emitting diode of the light-emitting diode array according to claim 1, the method comprising:

energizing the at least one light-emitting diode in synchronization with an image sequence controlled by an optical recording device such that individual frames of the image sequence are illuminated by associated light flashed from the at least one light-emitting diode.

18. Light-emitting diode array according to claim 1, in which the two light-emitting diodes differ in terms of their relative brightness.

19. Light-emitting diode array according to claim 1, in which the first light-emitting diode is a first light-emitting diode chip and the second light-emitting diode is a second light-emitting diode chip, wherein the first and the second light-emitting diode chip differ in terms of their size.