Hitachi, Ltd.

Hitachi Lighting, Ltd.

Hitachi Chemical Company, Ltd.

Hiroyuki Iyama

Teruichi Tomura

Mitsuo Akatsuka

Yoshio Watanabe

Kazuo Kaneko

Ichiro Imaizumi

Mineo Katsueda

Hironori Ishizaka

Masahiko Ohta

Kenji Ohmaru

Toshiaki Okada

Mitisuru Hirao

Takao Murata

Seizi Kado

A stripline patch antenna having a slot plate which is capable of obtaining higher antenna gain, while reducing the loss due to the feed lines. The antenna includes at least one radiating element for transmitting and receiving radio waves; a feed line for transmitting signals to and from the radiating element; a dielectric substrate for supporting the radiating element means and the feed line means; a grounding conductor located below the dielectric substrate; and a slot plate located above the dielectric substrate, having a plurality of slots more numerous than the radiating element. The triplate substrate can be adapted to this antenna. A plurality of antenna units so constructed can be arranged in array such that at least one of the slots of each antenna unit is shared with a neighboring antenna unit.

Stripline patch antenna with slot plate

Disclosed is a discharge lamp lighting device which comprises a series closed-loop circuit including an AC power supply, a ballast having an inductance, and a discharge lamp, and a switch circuit in parallel to the discharge lamp. The switch circuit is turned on when the voltage across the discharge lamp is reduced to zero, and then turned off when the current flowing in the switch reaches a predetermined value. The switch circuit thus repeats its on-off operation every half cycle of the voltage across the discharge lamp. The electromagnetic energy is stored in the inductance of the ballast when the switch circuit is on, and the stored electromagnetic energy is superimposed on the source voltage and applied to the discharge lamp when the switch circuit is turned off, thus reigniting the discharge lamp every half cycle. This makes it possible to light directly a discharge lamp having a lamp voltage approximate to the source voltage.

Discharge lamp lighting device

A discharge lamp lighting device comprises a serial connection of an inductive ballast and a discharge lamp connected across an A.C. power source, and a switching circuit connected substantially in parallel to the discharge lamp and operable to carry out two consecutive ON/OFF operations in the beginning of each half cycle of the A.C. power source while the discharge lamp is in its lit condition. The switching circuit preferably comprises a full-wave rectifier connected substantially in parallel to the discharge lamp, a switching element connected between the output terminals of the rectifier, and a control circuit for controlling the ON/OFF operation of the switching element.

A starter for a discharge lamp including first and second filaments, comprises an SCR having an anode and a cathode connected in series through the first and second filaments and a ballast transformer to an AC power supply. The gate electrode and the anode of the SCR are connected to each other through a first resistor, while the gate electrode is further connected through a second resistor to the power supply side.

Starter for discharge lamp

A voltage producing device comprises a circuit in which an AC power source, a coil and a first capacitor connected in series. A unidirectional triode semiconductor switching element is connected across both terminals of the capacitor, a voltage limiting semiconductor element is connected to a gate electrode of the switching element, and a charging-and-discharging circuit including a second capacitor is connected to a cathode of the switching element.

Discharge lamp control circuit

A solid state starter apparatus for a discharge lamp comprises a current limiter, an AC power supply, a discharge lamp of filament-preheating type and a switching circuit for controlling the turning on and off of the discharge lamp. The switching circuit further includes a lightedstate detector circuit for detecting the turning on or off of the discharge lamp, a current breaker circuit controlled by the lighted-state detector circuit to cause the filament current to be turned on and off, and a preheater circuit for starting to supply a filament preheating current in accordance with the magnitude of the current controlled by the current breaker circuit.

Solid state starter apparatus for a discharge lamp

An electric discharge lamp lighting circuit in which a discharge lamp is lighted by a circuit comprising a semiconductor switching circuit in which the cathode of a first thyristor is connected to the gate of a second thyristor and the first and second thyristors are commonly connected at the respective anodes, an integration circuit consisting of a capacitor and a resistor and connected between the gate of the first thyristor and the cathode of the second thyristor, a resistor connected between the integration circuit and the anode of the first thyristor, and a resistor connected between the gate and cathode of the second thyristor.

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Tokyo, Japan

Hiroyuki Iyama