Title:
LED DRIVE CIRCUIT
Document Type and Number:
Japanese Patent JP2002190392
Kind Code:
A
Abstract:
To keep the luminance of an LED backlight, allowing an LCD to be viewed easily, constant, for a comfortable sight-field for a user.
A power-source voltage 11 is connected to the anode of an LED12, and the cathode of the LED12 is connected to a current-limiting resistor 13. The current limiting resistor 13 branches into three: the first is connected to a drain of a transistor Tr14, the second is connected to a current-limiting resistor 15, and the third is connected to a current-limiting resistor 16. The current-limiting resistor 15 is connected to a drain of a Tr17 while the current- limiting resistor 16 is connected to a drain of a Tr18. The sources of the Trs are grounded, with a gate connected to a control part 19.
Inventors:
UCHIDA ATSUSHI
Application Number:
JP2000386273A
Publication Date:
July 05, 2002
Filing Date:
December 20, 2000
Export Citation:
Assignee:
NEC ACCESS TECHNICA LTD
International Classes:
G09G3/32; G09G3/34; G09G3/36; H01L33/00; H05B37/02; (IPC1-7): H05B37/02; G09G3/32; G09G3/34; G09G3/36; H01L33/00
Attorney, Agent or Firm:
Yutaro Kumagai
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