Electrodeless discharge lamp lighting device and lighting apparatus
First Claim
1. An electrodeless discharge lamp lighting device comprising:
- an induction coil wound in the vicinity of an electrodeless discharge lamp;
a power supply circuit for outputting a DC voltage;
an inverter circuit which has at least one switching element and which converts the DC voltage output from the power supply circuit into a high-frequency voltage and outputs the high-frequency voltage to the induction coil; and
a frequency varier that disperses the frequency of a noise by varying the frequency of the high-frequency voltage output from the inverter circuit to the induction coil at the time of lighting the electrodeless discharge lamp,wherein a frequency variation range Δ
f of the high frequency voltage output from the inverter circuit satisfies the expression;
Δ
f<
fav/Q1wherein, fav represents an average frequency of the high frequency voltage output from the inverter circuit to the induction coil at the time of lighting the electrodeless discharge lamp, andQ1 represents the value (X1/R1) obtained by dividing an imaginary component X1 by a real component R1, wherein X1 is the imaginary component of an impedance Z1 across both ends of the induction coil at a time of lighting the electrodeless discharge lamp at the average frequency fav, and R1 is the real component thereof.
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Accused Products
Abstract
There is provided an electrodeless discharge lamp lighting device with small size and low cost by simplifying a noise suppression part and a lighting apparatus having the electrodeless discharge lamp lighting device. A counter circuit of a frequency signal generating circuit repeatedly generates a frequency signal of which the amplitude is varied in a multi-step shape on the basis of an oscillation period of an oscillation circuit. An oscillation circuit outputs an oscillation signal of a frequency corresponding to the amplitude of the frequency signal. A drive circuit drives a switching element of an inverter circuit at the frequency of the oscillation signal and the inverter circuit applies a high-frequency voltage generated by the switching operation of the switching element to an induction coil to start up and light the electrodeless discharge lamp. That is, a high-frequency voltage which is varied at three discrete frequencies f1, f2, and f3 is repeatedly and periodically applied to the induction coil and thus a magnetic-component noise generated from a discharge lamp lighting device is distributed into three frequency components.
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Citations
18 Claims
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1. An electrodeless discharge lamp lighting device comprising:
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an induction coil wound in the vicinity of an electrodeless discharge lamp; a power supply circuit for outputting a DC voltage; an inverter circuit which has at least one switching element and which converts the DC voltage output from the power supply circuit into a high-frequency voltage and outputs the high-frequency voltage to the induction coil; and a frequency varier that disperses the frequency of a noise by varying the frequency of the high-frequency voltage output from the inverter circuit to the induction coil at the time of lighting the electrodeless discharge lamp, wherein a frequency variation range Δ
f of the high frequency voltage output from the inverter circuit satisfies the expression;
Δ
f<
fav/Q1wherein, fav represents an average frequency of the high frequency voltage output from the inverter circuit to the induction coil at the time of lighting the electrodeless discharge lamp, and Q1 represents the value (X1/R1) obtained by dividing an imaginary component X1 by a real component R1, wherein X1 is the imaginary component of an impedance Z1 across both ends of the induction coil at a time of lighting the electrodeless discharge lamp at the average frequency fav, and R1 is the real component thereof. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification