Denso Corporation

Nippondenso Co., Ltd.

Masamichi Ishikawa

Noboru Yamamoto

Kenji Yoneima

Hiroaki Okuchi

Hiromi Hiramatsu

Yuji Hayashi

Yasutoshi Horii

Goichi Oda

Kenji Aida

Yuji Kajita

Hideki Itou

Yasushi Noyori

Shinjiro Yasui

Yukinobu Hiranaka

Tomoyuki Ichikawa

A transformer includes a pair of first coils and at least one second coil. The first and second coils are stacked so that the at least one second coil is interposed between the first coils in a common winding axial direction of the first and second coils. Each of the first coils is covered by insulating films and integrated with the insulating films into an integrated body, so that the first coils are electrically insulated from the at least one second coil.

Transformer

A transformer has primary coils and secondary coils that are arranged in a laminated manner in a direction of a winding axis and are mutually insulated. The secondary coils are composed of conducting plates in a plurality of layers arranged in the laminated manner in the direction of the winding axis, and the conducting plates are electrically connected in series. Connecting portions between the each conducting plates are arranged in an inner space of the primary coils.

A mounting structure for mounting a discharge lamp lighting device is arranged to directly connect a discharge lamp provided in a headlight unit to a connector provided in the discharge lamp lighting device. The headlight unit includes a reflector, and the mounting structure comprises a holder for holding the discharge lamp, wherein the holder includes a holder securing portion directly connected to the reflector and is secured to the reflector via the holder securing portion. The discharge lamp is secured to the reflector via the holder. The mounting structure further comprises a securing member directly connected to the reflector for securing the discharge lamp lighting device to the reflector. The holder and the securing member are separated from each other and the discharge lamp lighting device is secured to the reflector via the securing member.

Mounting structure for a discharge lamp lighting device

A hybrid IC of electronic circuit for a discharge lamp is disposed on the bottom of a metal case. A transformer, an inductor, a transformer, and a capacitor are disposed in a resin case. The resin case is contained in a metal case. In this instance, the transformer, the inductor, the transformer, and the capacitor are located outside the outer periphery of the IC so that the IC does not overlap on the transformer and other components. The transformer for a starter circuit has a secondary winding the inductance of which is 2.5 mH or larger, and a capacitance of a smoothing capacitor of a DC&mdash;DC converter is 0.5 &mgr;F or smaller. The switching frequency f of a MOS transistor is selected so that L2&times;C1 is equal to or larger than 1&times;10 &times;f .

High voltage discharge lamp apparatus for vehicles

In a discharge lamp device, the electric power supplied to a discharge lamp is controlled in order of first to fourth control regions from the start of lighting of the discharge lamp. In the first control region, the lamp current is held constant until the lamp voltage reaches a first voltage value. In the second control region, the lamp current is reduced so as to have a correlation with a first time constant curve for a constant time after the lamp voltage reaches the first voltage value. In the third control region, the lamp current is reduced so as to have a correlation with a second time constant curve after a lapse of the constant time. The second time constant curve differs from the first time constant curve. In the fourth control region, a control value of the electric power supplied to the discharge lamp is free of a function of a lapse of time from the start of lighting of the discharge lamp, but is a function of at least the lamp voltage and the lamp current, and the electric power supplied to the discharge lamp is controlled by that control value. Through such a control, luminous flux is built up in a short time from the start of the lighting and an occurrence of overshoot or undershoot is minimized to a possible extent.

Discharge lamp device having a light distribution compound lens

A lamp current i.sub.L flows through a first resistor. Electric current I, which is the output current of a voltage-current converter which converts a lamp voltage V.sub.L to a lamp current I, flows through a second resistor. Feedback control is executed to make V.sub.-, which is the voltage of one terminal of the second resistor, equal a reference voltage V.sub.ref. The power applied to the lamp during start-up is controlled to be the same as the power applied to the lamp during its stable lighting for a predetermined lamp voltage range. Using the following two linear equations, the electric current I is set as I=aV.sub.L +b (where a and b are positive constants) when the lamp voltage V.sub.L is lower than a first predetermined voltage V.sub.a which is less than the lamp voltage during the normal stable lighting period of the lamp, and as I=cV.sub.L +d (where c and d are positive constants with c&lt;a and d&gt;b), when the lamp voltage V.sub.L is greater than or equal to the first predetermined value V.sub.a.

Lamp control circuit having a V-I converter with slopes of different

A semiconductor switching element is connected to the first winding of a transformer. A smoothing capacitor is connected to the second winding of the transformer through a rectifier diode. The charging voltage Va of this smoothing capacitor serves as the applied voltage of a discharge lamp. When the discharge lamp is lighting, the second winding serves as a power source for supplying power to the discharge lamp. A capacitor is connected to the third winding of the transformer through a rectifier diode. The charging voltage of this capacitor serves as the applied voltage of a discharge tube. When the discharge tube discharges, a high-voltage starting pulse is provided to the secondary winding of a high-voltage coil, thereby rendering the discharge lamp ready for lighting. Therefore, when the discharge lamp is starting, the third winding serves as a power source for supplying starting power to the discharge lamp.

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Hekinan, Japan

Masamichi Ishikawa