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Title:
ACTUATOR DRIVE CIRCUIT FOR SHUTTER AND ACTUATOR FOR SHUTTER
Document Type and Number:
WIPO Patent Application WO/2005/121890
Kind Code:
A1
Abstract:
An actuator drive circuit for a shutter capable of operating an actuator with high precision. The actuator drive circuit (1) for shutter comprises a counter (12) which starts counting frequency division clocks produced by dividing the frequency of a reference clock by an actuation signal, a D/A converter (13) outputting a conversion voltage (VDAC) that increases stepwise gradually depending on the output from the counter, a coil current control amplifier (15) comparing, immediately after start, a coil current detection voltage (VDET) corresponding to the value of the coil current (IL) of a shutter actuator (8) with the conversion voltage (VDAC), comparing the coil current detection voltage (VDET) with a coil current limitation reference voltage (VREF) after the conversion voltage (VDAC) matches the coil current limitation reference voltage (VREF) corresponding to the upper limit of the coil current (IL) and then outputting a voltage obtained by amplifying the difference, and a driving current output circuit (16) for outputting the driving current of the shutter actuator (8) depending on the amplified output voltage of the coil current control amplifier (15).

Inventors:
Sasamoto, Yutaka c/o ROHM CO. LTD. (21, Saiin Mizosaki-cho, Ukyo-ku, Kyoto-sh, Kyoto 85, 61585, JP)
Application Number:
PCT/JP2005/010562
Publication Date:
December 22, 2005
Filing Date:
June 09, 2005
Export Citation:
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Assignee:
ROHM CO., LTD. (21 Saiin Mizosaki-cho, Ukyo-ku Kyoto-sh, Kyoto 85, 61585, JP)
Sasamoto, Yutaka c/o ROHM CO. LTD. (21, Saiin Mizosaki-cho, Ukyo-ku, Kyoto-sh, Kyoto 85, 61585, JP)
International Classes:
G03B9/08; G03B7/083; H02P7/06; H02P7/28; (IPC1-7): G03B9/08
Foreign References:
JP2003235293A2003-08-22
JP2003043554A2003-02-13
JPH0641398U1994-05-31
JPH02262630A1990-10-25
JPS6146708U1986-03-28
JPS63146416A1988-06-18
JP2001033845A2001-02-09
JPS59116633A1984-07-05
JP2567230B21996-12-25
JP2608705B21997-05-14
Attorney, Agent or Firm:
Fukami, Hisao (Fukami Patent Office, Nakanoshima Central Tower 22nd Floor, 2-7, Nakanoshima 2-chome, Kita-k, Osaka-shi Osaka 05, 53000, JP)
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