Hitachi, Ltd.

Tsune Miyashita

Makoto Yasuda

Seiichi Murayama

Yoji Arai

Katsuki Miyauchi

Gyozo Toda

Iwao Matsuyama

Kazunori Kinoshita

Shigeru Jyomura

Kenichi Kawasumi

Fuzio Yamada

Disclosed is an apparatus for stabilizing the light output of a high pressure discharge lamp comprising a coil generating a magnetic field acting upon the arc of the high pressure discharge lamp, an arc position detector detecting deviation of the position of the arc, and a magnetic field control circuit controlling the coil in response to the deviation detection output signal of the the arc position detector thereby setting right the position of the arc of the high pressure discharge lamp.

Apparatus for automatically correcting arc position of high pressure

A high-pressure discharge lamp operating circuit performs a low-frequency AC operating at an early stage of operating and thereafter performs a high-frequency AC operation or DC operation during the steady-state of lamp operation. This circuit comprises a circuit for effecting a transition from the low-frequency AC operation to the high-frequency AC operation or DC operation either at the time which is a predetermined time period after the ignition of discharge before the high-pressure discharge lamp reaches the steady-state of operation, or after having detected at least one of predetermined lamp characteristics, thereby providing a stabilized light output.

High-pressure discharge lamp operating circuit

An instrument for spectroscopy according to this invention uses a metal halide lamp, in which at least mercury and dysprosium halide are enclosed, as the light source for the purpose of effecting measurements for a wavelength region extending from the ultraviolet to the visible light with a single light source. This metal halide lamp has a spectre, which is effective in a wavelength region extending from about 200 nm to about 700 nm.

Instrument for spectroscopy having metal halide lamp as light source

A discharge lamp comprising an inner arc tube and an outer tube enclosing the inner tube. The outer tube is filled with neon at a pressure of 0.1 atm or more, or a gas mixture of neon in 80 pressure percent or more and breakdown suppressing gas.

Discharge lamp with neon gas in outer tube

A high pressure discharge lamp in which discharge between a pair of main electrodes in an arc tube of the discharge lamp is sustained by a D.C. or high frequency current. The circuit comprises discharge mode controller for controlling the discharge such that mainly a low-frequency discharge is produced between the main electrodes at least within a predetermined time from initiation of the discharge within the arc tube, and subsequently transferred to the D.C. or high-frequency discharge.

A pulse generator comprising an induction element, and a nonlinear condenser whose dielectric material portion is made of ferroelectric ceramics represented by a general formula of (Pb.sub.1-x-y, Ba.sub.x, Sr.sub.y)(Ti.sub.z, Zr.sub.1-z)O.sub.3.

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Tokyo, Japan

Tsune Miyashita