Mitsubishi Denki Kabushiki Kaisha

Other

Mitsubishi Electric Lighting Corporation

Osram-melco Ltd.

Mitsubishi Electric Corporation

Mitsubishi Electric Home Appliance Co., Ltd.

Hiroyasu Kisaichi

Satoshi Nagai

Hiroyoshi Yamazaki

Koshiro Takano

Kenichiro Nishi

Akira Morii

Masatomi Asayama

Takahisa Hamaguchi

Fumitake Oowada

A high pressure discharge lamp lighting apparatus is provided which prevents dying out or instabilities of the discharge arc inside the arc tube due to the acoustic resonance phenomena and enables to light the high pressure discharge lamp in a steady state. In the high pressure discharge lamp lighting apparatus having the high pressure discharge lamp, the lamp voltage detecting device, the high frequency power supplying device, and the control circuit, the apparatus includes an extracting device for extracting an upper limit frequency and a lower limit frequency of the resonance-free frequency band, and the control circuit includes a frequency moving device for changing the frequency of the high frequency power within a range defined by the upper limit frequency and the lower limit frequency extracted by the extracting device and then moving the frequency to a predetermined frequency which is determined based on the upper limit frequency and the lower limit frequency.

High pressure discharge lamp lighting apparatus and high pressure discharge lamp lighting method

The discharge lamp lighting apparatus has a step-up/step-down converter comprising a transformer , a first switching element serially connected to the transformer on a side of a commercial ac power source , and a first diode and a first capacitor connected to the transformer on the load side; zero-cross detection means for detecting the zero-cross of voltage of the commercial ac power source ; a supplemental power circuit comprising a second diode connected to the junction between the transformer and the first switching element , a second capacitor for charging electric power stored in the coil of the transformer on a side of the commercial ac power source via the second diode , and a second switching element , a third diode and an inductance through which the energy charged in the second capacitor is supplied to the discharge lamp ; and a control circuit that operates the second switching element in the supplemental power means based on the output from the voltage zero-cross detection means during a predetermined period of time around the zero-cross.

Discharge lamp lighting apparatus and lamp apparatus

This invention provides a discharge lamp lighting device and illumination device which can be miniaturized with high power factor and also is inexpensive. In the discharge lamp lighting device, in response to the zero crossing detected signal of a commercial AC power source detected by a detecting section, a voltage boosting/dropping circuit boosts or drops the commercial AC power source full-wave rectified by a rectifying circuit so that the current flowing through the discharge lamp is larger in the vicinity of the phases of 90&deg; and 270&deg; of the commercial AC power source than in the vicinity of the phases of 0&deg; and 180&deg; thereof, and a polarity changing circuit changes the polarity of the boosted or dropped current to be supplied to the discharge lamp. An illumination device is provided with such a discharge lamp lighting device.

Discharge lamp lighting device and illumination device

To provide a high-pressure discharge lamp lighting apparatus which is adapted to be used in common for several kinds of AC voltages such as 100 V and 200 V, which is small in size, and which can secure good starting property with less circuit loss in use at any of the AC voltages, the apparatus is provided with a diode bridge for rectifying an AC voltage, an active filter for converting, with a high power factor, an AC voltage into a DC voltage, a current limiting circuit for controlling the current to be made to flow in the high-pressure discharge lamp, an inverter for converting a DC voltage into a low-frequency AC voltage, a high-voltage pulse circuit for generating a high-voltage pulse for starting the high-pressure discharge lamp, and a control circuit for controlling the active filter, the current limiting circuit, the inverter, a discharge-lamp voltage detecting circuit, a discharge-lamp current detecting circuit and the high-voltage pulse circuit.

High-pressure discharge lamp lighting apparatus

A high voltage discharge lamp device may include a step-up DC-DC converter connected to a power switch; polarity switching elements for alternatively changing the polarities of the electric voltage outputted from the step-up DC-DC converter; and a polarity switching drive circuit for activating the polarity switching elements. Also, a high voltage discharge lamp device may include a pair of first and second step-up DC-DC converters connected to a power switch; polarity switching elements for alternatively changing the output polarities of the respective first step-up DC-DC converter and the second step-up DC-DC converter; and a polarity switching drive circuit for activating the polarity switching elements. The polarity switching drive circuit operates in synchronization with the on/off actions of the power switch, or in synchronization with either ultra low-frequency signals or low-frequency signals.

High voltage discharge lamp device

Growing community of inventors

Tokyo, Japan

Hiroyasu Kisaichi