Title:
CURRENT DRIVER, LED DRIVING CIRCUIT, LIGHTING DEVICE AND ELECTRONIC APPARATUS
Document Type and Number:
Japanese Patent JP2017028866
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To simply perform phase shift burst light control.SOLUTION: LED bars 6 of N channels at maximum are connectable to a current driver 8. A pulse measuring circuit 12 measures a period Tand a pulse width Tof external dimming pulses Shaving a duty ratio corresponding to a target light amount common to the LED bars 6 to generate digital period data Dand pulse width data D. An interface circuit 14 is connected to an external processor, and receives (i) enable data S1 designating M pieces of the LED bars 6 as a driving target, and (ii) phase difference setting data S2 designating one of plural selectable phase differences 360°/2, 360°/3 to 360°/N. A pulse generator 20 generates M pieces of internal dimming pulses Swhich have a period represented by the period data Dand a pulse width represented by the pulse width data D, and have a phase difference corresponding to the phase difference setting data S2.SELECTED DRAWING: Figure 3
Inventors:
NOZAWA TAKESHI
HARUTA SHINGO
HARUTA SHINGO
Application Number:
JP2015145205A
Publication Date:
February 02, 2017
Filing Date:
July 22, 2015
Export Citation:
Assignee:
ROHM CO LTD
International Classes:
H02M3/155; H01L33/00; H05B44/00; H05B37/02
Attorney, Agent or Firm:
Sakaki Morishita
Masaki Taiki
Masaki Taiki