Title:
Lighting device
Document Type and Number:
Japanese Patent JP6134492
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a lighting device for a discharge lamp and an LED, that can be in common to AC power supplies with different outputs, and that has a high circuit efficiency independently of a lighting voltage of the discharge lamp or the LED.SOLUTION: A lighting device comprises: a rectification circuit 14 rectifying an AC voltage via an input filter circuit 12; a power factor improving circuit 16 receiving an output voltage Vof the rectification circuit 14, stepping up to a predetermined voltage V, and increasing an input power factor; a PWM step-down circuit 18 making an output power of the power factor improving circuit 16 constant; a rectangular wave generation circuit 20 converting an output voltage Vof the PWM step-down circuit 18 into an alternating rectangular wave, and supplying it to a discharge lamp; and an output filter circuit 22 and a starter circuit 24 for initiation. The lighting device further comprises a control circuit 42 setting a switching frequency fof a switching element Qof the power factor improving circuit 16 depending on an input voltage Vdetected by input voltage detection means 44. The control circuit 42 reduces the step-up switching frequency fin the case that the input voltage Vis low, compared with the case that the input voltage Vis high.
Inventors:
Tomokazu Osato
Kensuke Kaneko
Kensuke Kaneko
Application Number:
JP2012230663A
Publication Date:
May 24, 2017
Filing Date:
October 18, 2012
Export Citation:
Assignee:
Eye Lighting System Co., Ltd.
International Classes:
H05B41/24; H05B37/02
Domestic Patent References:
| JP9055296A | ||||
| JP2007209083A | ||||
| JP2004282958A |
Attorney, Agent or Firm:
Yuji Iwahashi