Title:
VEHICLE LAMP FIXTURE AND LIGHTING CIRCUIT FOR SAME
Document Type and Number:
WIPO Patent Application WO/2017/150322
Kind Code:
A1
Abstract:
In the present invention, a current detection circuit (34) generates a current detection signal VCS which is commensurate to a lamp current ILAMP supplied from a switching converter (30) to a semiconductor light source (10). A hysteresis comparator (36) compares the current detection signal VCS to an upper threshold value signal VTHH and a lower threshold value signal VTHL which are determined in accordance with an analog light-modulation signal VADIM, and generates a control pulse SCNT in accordance with the result of the comparison. A driver (38) drives a switching transistor M1 in accordance with the control pulse SCNT. A PWM light-modulation circuit (90) smoothes out a pulse width modulation (PWM) light-modulation signal SPWM and generates a gradually-varying signal, then varies the analog light modulation signal VADIM on the basis of the gradually-varying signal.
Inventors:
ICHIKAWA TOMOYUKI (JP)
KIKUCHI SATOSHI (JP)
KIKUCHI SATOSHI (JP)
Application Number:
PCT/JP2017/006743
Publication Date:
September 08, 2017
Filing Date:
February 23, 2017
Export Citation:
Assignee:
KOITO MFG CO LTD (JP)
International Classes:
H05B37/02; B60Q1/00; H05B44/00; B60Q1/14; H01L33/00; H02M3/155
Foreign References:
| JP2012226917A | 2012-11-15 | |||
| JP2016058240A | 2016-04-21 |
Other References:
See also references of EP 3426009A4
Attorney, Agent or Firm:
MORISHITA Sakaki (JP)
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