DRIVE CIRCUIT FOR SEMICONDUCTOR LIGHT EMITTING ELEMENT, AND LIGHT SOURCE DEVICE, LIGHTING DEVICE, MONITOR DEVICE, AND IMAGE DISPLAY DEVICE USING THE DRIVE CIRCUIT

• US 20090059981A1
• Filed: 08/12/2008
• Published: 03/05/2009
• Est. Priority Date: 08/31/2007
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: MIZUSAKO, Kazuhisa, SUDO, Kiyoto
• Granted Patent: US 8,040,930 B2
• Time in Patent Office: Days
• US Class Current: 372/38.20
• CPC Class Codes: H01S 3/109 Frequency multiplication, e.g. harmonic generation
• CPC Class Codes: H01S 5/042 Electrical excitation ; Circuits therefor monolithically integrated laser drive components H01S5/0261
• CPC Class Codes: H01S 5/0427 for applying modulation to the laser
• CPC Class Codes: H01S 5/0428 for applying pulses to the laser
• CPC Class Codes: H01S 5/14 External cavity lasers H01S5/18 takes precedence; mode locking H01S5/065
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05K 1/0228 Compensation of cross-talk by a mutually correlated lay-out of printed circuit traces, e.g. for compensation of cross-talk in mounted connectors balanced signal pairs H05K1/0245
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 2201/0792 Means against parasitic impedance; Means against eddy currents
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: H05K 2201/10166 Transistor
• CPC Class Codes: H05K 2201/10545 Related components mounted on both sides of the PCB
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A drive circuit for driving a semiconductor light emitting element includes a board, a first pattern formed in a first layer of the board so as to be electrically connected to an anode of the semiconductor light emitting element, and a second pattern formed in a second layer of the board so as to be electrically connected to a cathode of the semiconductor light emitting element, and the first pattern and the second pattern are formed so as to overlap with each other when viewed in a direction along a normal line of the board.

Claims

1. A drive circuit for driving a semiconductor light emitting element, comprising:

a board;

a first pattern formed in a first layer of the board so as to be electrically connected to an anode of the semiconductor light emitting element; and

a second pattern formed in a second layer of the board so as to be electrically connected to a cathode of the semiconductor light emitting element,

wherein the first pattern and the second pattern are formed so as to overlap with each other when viewed in a direction along a normal line of the board.

2. The drive circuit according to claim 1,

wherein a width of the first pattern and a width of the second pattern are substantially the same.

3. The drive circuit according to claim 1,

wherein a first direction in which a current flowing through the semiconductor light emitting element flows through the first pattern and a second direction in which the current flows through the second pattern are reverse to each other.

4. The drive circuit according to claim 1,

wherein the board is formed of a rigid board.

5. The drive circuit according to claim 4,

wherein the semiconductor light emitting element is allowed to be disposed on a side of the rigid board.

6. The drive circuit according to claim 4, further comprising:

a flexible board;

a third pattern formed in a third layer of the flexible board, and through which the first pattern and the anode are to be electrically connected to each other; and

a fourth pattern formed in a fourth layer of the flexible board, and through which the second pattern and the cathode are to be electrically connected to each other,

wherein the third pattern and the fourth pattern are formed so as to overlap with each other when viewed in a direction along a normal line of the flexible board.

7. The drive circuit according to claim 6,

wherein a width of the third pattern and a width of the fourth pattern are substantially the same.

8. The drive circuit according to claim 6,

wherein a third direction in which a current flowing through the semiconductor light emitting element flows through the third pattern and a fourth direction in which the current flows through the fourth pattern are reverse to each other.

9. The drive circuit according to claim 6,

wherein the semiconductor light emitting element is allowed to be disposed on a side of the flexible board.

10. The drive circuit according to claim 4, further comprising:

a switching element to be connected to the semiconductor light emitting element,

wherein the switching element is disposed inside an area in which the second pattern is formed.

11. The drive circuit according to claim 1,

wherein the board is formed of a flexible board.

12. The drive circuit according to claim 11,

wherein the semiconductor light emitting element is allowed to be disposed on a side of the flexible board.

13. The drive circuit according to claim 11, further comprising:

a switching element to be connected to the semiconductor light emitting element,

wherein the switching element is disposed inside an area in which the second pattern is formed.

14. A light source device comprising:

the drive circuit according to claim 1; and

the semiconductor light emitting element.

15. A lighting device comprising:

the light source device according to claim 14.

16. A monitor device comprising:

the light source device according to claim 14; and

an imaging section for shooting an object lighted by the light source device.

17. An image display device comprising:

the light source device according to claim 14; and

a light modulation device for modulating the light emitted from the light source device in accordance with image information.