Minebea Company, Limited

Hiroshi Shinmen

Robert Weger

Kohei Nishibori

Mitsuo Matsushima

Masashi Norizuki

To provide a multiple-light discharge lamp lighting device that stabilizes and equalizes tube current of a plurality of discharge lamps without arranging a Ballast element to the secondary side of an inverter transformer with low costs. A multiple-light discharge lamp lighting deviceaccording to the present invention includes inverter meansand a plurality of inverter transformers TRto TR. Discharge lamps Lato Laare connected to secondary windings Nsto Nsn of the inverter transformers TRto TR. Preferably, variable impedance elements Zto Z, as variable inductance elements, are serially connected to primary windings Npto Npn of the plurality of inverter transformers TRto TR. Accordingly, the tube current can be stabilized and equalized without using an element resistant to a high voltage.

Multiple-light discharge lamp lighting device

A multiple discharge lamp lighting apparatus is provided which achieves stable and uniform lamp currents in a plurality of discharge lamps without a ballast element at the secondary side of an inverter transformer. The multiple discharge lamp lighting apparatus includes an inverter, and a plurality of inverter transformers each of which has a discharge lamp connected at a secondary winding thereof. A balance inductance element is provided between the primary side wirings of any adjacent pair of the plurality of inverter transformers. Each of the inverter transformers includes a tight coupling section and a loose coupling section, which function as a balance coil and an impedance element, respectively, whereby the lamp currents of the discharge lamps are stabilized and equalized without using a high withstand voltage element.

Multiple discharge lamp lighting apparatus

There is provided a multiple discharge lamp lighting apparatus, which includes an inverter and plurality of inverter transformer. In the multiple discharge lighting apparatus, a discharge lamp is connected to the secondary winding of each inverter transformer, a ballast impedance element is connected in series between a switch of the inverter and the primary winding of each inverter transformer, and a current balancing unit is provided between each two adjacent inverter transformers.

An inverter transformer in which to overall structure and manufacturing process can be simplified despite its closed magnetic path structure, and a cost increase can be suppressed. Primary windings (,,) and secondary windings (,,) wound around a plurality of rod-like cores (,,) have leakage inductances. The primary windings (,,) axe wound around respective rod-like cores (,,) such that magnetic fluxes being induced in respective cores by the currents flowing through the primary windings (,,) are directed reversely to magnetic fluxes being induced in adjacent cores.

Inverter transformer

A discharge lamp lighting apparatus is provided for lighting a plurality of discharge lamps including one reference lamp and at least one controllable lamp. First variable inductance element and lamp current detecting unit are connected to the reference lamp, second variable inductance and lamp current unit are connected to the controllable lamp, and a lamp current controlling circuit is connected to each of the first and second variable inductance elements. An output signal from the second lamp current detecting unit and also an output signal as a reference signal from the first lamp current detecting unit are connected to the lamp current controlling circuit for the controllable lamp, whereby the lamp current of the controllable lamp is controlled. The reference output signal is also connected to a control circuit, and the lamp currents of the reference and controllable lamps are controlled further by the on/off operation of the switching elements.

Discharge lamp lighting apparatus for lighting multiple discharge lamps

In a discharge lamp lighting apparatus to light two discharge lamps, one terminal of the secondary side of a step-up transformer is connected to one terminal of each of the two discharge lamps, the other terminal of each of the two discharge lamps is connected, via each of two variable inductance elements, to one lamp current detecting unit, a signal of each lamp current detecting unit is connected to a lamp current control circuit, and an output signal from each lamp current control circuit is connected to each variable inductance element so as to vary the inductance of each variable inductance element, whereby the lamp current flowing through each discharge lamp is controlled.

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Kitasaku-gun, Japan

Hiroshi Shinmen