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US 7,116,063 B2Granted
Dimmable discharge lamp lighting device
AssigneeMatsushita Electric Works, Ltd.
InventorsNaoki Ohnishi, Shigeru Ido
Life of this patent
Estimating the term…
Abstract
A discharge lamp lighting device includes a high frequency power supply for supplying high frequency power to the discharge lamp via a first impedance element, a DC power supply for applying DC voltage to the discharge lamp via a second impedance element, a dimming control circuit for carrying out a dimming of the discharge lamp by controlling the power supplied to the discharge lamp, a DC voltage detection circuit for detecting a DC component of the voltage applied to the discharge lamp, and an output correction unit for making a correction to the power supplied to the discharge lamp in accordance with a value detected by the DC voltage detection circuit. It can light the discharge lamp stably regardless of a variation in temperature.
Claims11
A discharge lamp lighting device comprising:
- a high frequency power supply for supplying a high frequency power to a discharge lamp via a first impedance element;
- a DC power supply for applying a DC voltage to the discharge lamp via a second impedance element;
- a dimming control circuit for carrying out a dimming of the discharge lamp by controlling a power supplied to the discharge lamp;
- a DC voltage detection circuit for detecting a DC voltage component applied to the discharge lamp;
- and
- an output correction unit for making a correction to the power supplied to the discharge lamp according to a value detected by the DC voltage detection circuit, wherein the output correction unit raises an output to the discharge lamp if the DC voltage component applied to the discharge lamp has increased, and reduces the output to the discharge lamp if the DC voltage component applied to the discharge lamp has decreased.
3 more elements
A discharge lamp lighting device comprising:
- a high frequency power supply for supplying a high frequency power to a discharge lamp via a first impedance element;
- a DC power supply for applying a DC voltage to the discharge lamp via a second impedance element;
- a dimming control circuit for carrying out a dimming of the discharge lamp by controlling a power supplied to the discharge lamp;
- a DC voltage detection circuit for detecting a DC voltage component applied to the discharge lamp;
- and
- an output correction unit for making a correction to the power supplied to the discharge lamp according to a value detected by the DC voltage detection circuit, wherein the output correction unit controls an output to the discharge lamp by clamping the value detected by the DC voltage detection circuit at a predetermined value.
3 more elements
A discharge lamp lighting device comprising:
- a high frequency power supply for supplying a high frequency power to a discharge lamp via a first impedance element;
- a DC power supply for applying a DC voltage to the discharge lamp via a second impedance element;
- a dimming control circuit for carrying out a dimming of the discharge lamp by controlling a power supplied to the discharge lamp;
- a DC voltage detection circuit for detecting a DC voltage component applied to the discharge lamp;
- and
- an output correction unit for making a correction to the power supplied to the discharge lamp according to a value detected by the DC voltage detection circuit, wherein the output correction unit controls an output to the discharge lamp by controlling an impedance value of the second impedance element, and wherein the impedance value of the second impedance element is adjusted by controlling a duty ratio of a driving signal to drive a switch element connected in series or in parallel to the discharge lamp.
3 more elements
A discharge lamp lighting device comprising:
- a high frequency power supply for supplying a high frequency power to a discharge lamp via a first impedance element;
- a DC power supply for applying a DC voltage to the discharge lamp via a second impedance element;
- a dimming control circuit for carrying out a dimming of the discharge lamp by controlling a power supplied to the discharge lamp;
- a DC voltage detection circuit for detecting a DC voltage component applied to the discharge lamp;
- and
- an output correction unit for making a correction to the power supplied to the discharge lamp according to a value detected by the DC voltage detection circuit, wherein the output correction unit includes a fluctuation voltage detection circuit for detecting a fluctuation of the DC voltage component applied to the discharge lamp, and if the fluctuation voltage detection circuit detects an increase of the fluctuation of the DC component, the output correction unit increases the power to the discharge lamp.
3 more elements
A discharge lamp lighting device comprising:
- a high frequency power supply for supplying a high frequency power to a discharge lamp via a first impedance element;
- a DC power supply for applying a DC voltage to the discharge lamp via a second impedance element;
- a dimming control circuit for carrying out a dimming of the discharge lamp by controlling a power supplied to the discharge lamp;
- a DC voltage detection circuit for detecting a DC voltage component applied to the discharge lamp;
- and
- an output correction unit for making a correction to the power supplied to the discharge lamp according to a value detected by the DC voltage detection circuit, wherein the output correction unit includes a fluctuation voltage detection circuit for detecting a fluctuation of the DC voltage component applied to the discharge lamp and a frequency detection circuit for detecting a frequency of the fluctuation of the DC voltage component detected by the fluctuation voltage detection circuit, and if the frequency of the fluctuation of the DC voltage component is within a specific frequency range, the output correction unit increases a DC power or an AC power to the discharge lamp until the frequency of the fluctuation goes out of the specific frequency range.
3 more elements
Dependencies are inferred from the claim text.