Title:
FREQUENCY SYNCHRONIZING METHOD FOR DISCHARGE TUBE LIGHTING APPARATUS, DISCHARGE TUBE LIGHTING APPARATUS, AND SEMICONDUCTOR INTEGRATED CIRCUIT
Document Type and Number:
WIPO Patent Application WO/2008/044413
Kind Code:
A1
Abstract:
A discharge tube lighting apparatus operates as follows: (1) an oscillator generates a
triangle wave signal having the same charging and discharging slopes of a capacitor (C2)
and turns on and off FETs (Qp1, Qn1); (2) a signal generation portion generates a
first drive signal for driving the Qp1 with a pulse width corresponding to a current flowing
through the discharge tube during less than half cycle of the triangle wave signal
so as to make the current flow through the discharge tube, and a second drive signal
having substantially the same pulse width as and a phase difference of about 180
degrees from the first drive signal for driving Qn1 so as to make current flow through
the discharge tube in the opposite direction to that in the case where the first
drive signal is generated; and (3) a current pulse current generation circuit
converts a synchronous pulse voltage signal to a pulse current having positive
and negative current values changing at a duty of about 50% and each having the
same absolute value and superimposes the converted pulse current onto the triangle
wave signal, and the signal generation portion generates the first and second
drive signals in synchronization with the frequency of the pulse current.
Inventors:
KIMURA KENGO
Application Number:
PCT/JP2007/067611
Publication Date:
April 17, 2008
Filing Date:
September 10, 2007
Export Citation:
Assignee:
SANKEN ELECTRIC CO LTD (JP)
KIMURA KENGO
KIMURA KENGO
International Classes:
H05B41/24
Foreign References:
| US5615093A | 1997-03-25 | |||
| JP2002319499A | 2002-10-31 | |||
| JPH1050491A | 1998-02-20 | |||
| JPH10285942A | 1998-10-23 | |||
| JP2005005059A | 2005-01-06 | |||
| JPH1097898A | 1998-04-14 |
Attorney, Agent or Firm:
MIYOSHI, Hidekazu et al. (2-8 Toranomon 1-chome,Minato-k, Tokyo 01, JP)
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