Invention Grant
- Patent Title: LED driving device, lighting device, and vehicle-mounted display device
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Application No.: US17274669Application Date: 2019-02-21
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Publication No.: US11412594B2Publication Date: 2022-08-09
- Inventor: Ryosuke Kanemitsu , Koji Katsura
- Applicant: ROHM CO., LTD.
- Applicant Address: JP Kyoto
- Assignee: ROHM CO., LTD.
- Current Assignee: ROHM CO., LTD.
- Current Assignee Address: JP Kyoto
- Agency: Fish & Richardson P.C.
- Priority: JPJP2018-169705 20180911
- International Application: PCT/JP2019/006482 WO 20190221
- International Announcement: WO2020/054096 WO 20200319
- Main IPC: H05B45/30
- IPC: H05B45/30 ; H05B45/3725 ; B60Q3/18 ; H05B45/345 ; H05B45/56 ; H05B45/325 ; H05B45/10

Abstract:
An LED driving device includes a DC/DC controller which controls an output stage for supplying an output voltage to an LED; and a current driver which generates an output current of the LED. The current driver performs PWM dimming by turning on the output current in accordance with an LED-current-on period of a PWM dimming signal and turning off the output current in accordance with an LED-current-off period of the PWM dimming signal. The DC/DC controller includes a feedback control unit which performs feedback control for outputting a switching pulse to the output stage so as to make a cathode voltage of the LED equal to a reference voltage. A pulse addition control unit performs pulse addition control for adding a predetermined pulse number of additional switching pulses at a time of switching between the LED-current-on period and the LED-current-off period.
Public/Granted literature
- US20210274616A1 LED DRIVING DEVICE, LIGHTING DEVICE, AND VEHICLE-MOUNTED DISPLAY DEVICE Public/Granted day:2021-09-02
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