Circuit for illuminator

• US 20040042205A1
• Filed: 09/02/2003
• Published: 03/04/2004
• Est. Priority Date: 09/03/2002
• Status: Abandoned Application

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Tanabe, Tetsuo, Tauchi, Shigeaki
• Application Number:
  US10/652,513
• Publication Number:
  US 20040042205A1
• Time in Patent Office: Days
• US Class Current: 362/189
• CPC Class Codes: H05B 45/40 Details of LED load circuits
• CPC Class Codes: H05B 45/52 in a parallel array of LEDs

Abstract

A circuit for an illuminator includes LEDs (DL1, . . . , DL6) which are connected to resistors (R1, . . . , R6) respectively in series to provide six series units and twos of these series units therein are connected in parallel and moreover threes of these parallel units are connected in series in a lattice arrangement. Even when DL2 undergoes disconnection, for example, an increased amount of current flowing in DL1 can thus be restrained as much as possible and even when LEDs with variable forward voltage are connected in parallel, a difference in the flowing amount of current between the LEDs is minimized and a difference in brightness is substantially nullified. Moreover, as resistors are added to the respective units, the number of LEDs can freely be changed by directly connecting units with the omission of the LED.

Claims

1. A circuit for an illuminator comprising a plurality of units each comprising a light emitting diode and a resistor which are connected in series, wherein said plurality of units are connected in parallel to form a parallel circuit, and a plurality of said parallel circuits are further connected in series to form a lattice network.

2. A circuit for an illuminator according to claim 1, further comprising a series unit without having the light emitting diode, said series unit being incorporated in at least one of said parallel circuits.

3. A circuit for an illuminator according to claim 2, wherein said series unit is constituted by forming a short circuit between terminals to be fitted with an anode and cathode of the light emitting diode without coupling the light emitting diode.

4. A circuit for an illuminator according to claim 3, wherein said short circuit comprises a jumper line.

5. A circuit for an illuminator according to claim 1, further comprising a dummy diode incorporated in place of the light emitting diode in the unit.

6. A stop lamp comprising the circuit according to claim 1.

7. A direction indicator comprising the circuit according to claim 1.

8. A rear lighting equipment comprising the circuit according to claim 1.

9. A headlamp comprising the circuit according to claim 1.