Iwasaki Electric Co., Ltd.

Makoto Ohkahara

Shoji Yamamoto

Yosuke Kano

Tooru Nagase

Shinichi Suzuki

Nobuo Fukuda

Yoshiaki Komatsu

Hirokazu Harasawa

Yoshiaki Kuroda

Toshio Yoshizawa

Yousuke Ishikawa

Sumio Uehara

Shinichi Takemasa

Katsuhiro Okabe

Shigeharu Sato

A starting light source for radiating the UV-light to a discharge chamber upon starting lighting of a high pressure discharge lamp includes a discharge tube for generating the UV-light by a starting voltage applied upon starting lighting the lamp, the discharge tube includes an internal electrode extended from a pinch seal portion formed at one end to a light-emitting portion thereof and an external electrode disposed close to or in contact with both of the light-emitting portion and the pinch seal portion, at least a portion of the external electrode disposed for the light-emitting portion includes a holder formed by bending fabrication of a metal sheet into such a shape of gripping and holding the discharge tube, and a terminal is formed to the holder for fixing and electrically connecting the external electrode to a conductor part having a polarity opposite to that of the internal electrode.

Light source device with starting aid

The high pressure discharge lamp ballast drives a high pressure discharge lamp with a synthesized-waveform alternating current made of multiple frequency components, the high pressure discharge lamp having a pair of electrodes disposed to face each other. The ballast controls a ratio of the multiple frequency components per unit time; applies a synthesized-waveform current in accordance with the ratio to the high pressure discharge lamp; and detects a lamp parameter of the high pressure discharge lamp. The control circuit is configured to shift the ratio to a first ratio when the lamp parameter is in a first state, and shifts the ratio to a second ratio when the lamp parameter is in a second state. The control circuit changes the ratio stepwise when the ratio is shifted from the first ratio to the second ratio, or when the ratio is shifted from the second ratio to the first ratio.

High pressure discharge lamp ballast and light source apparatus

A high pressure discharge lamp ballast performs driving with a synthesized current waveform comprising a combination of first and second sets of current waveforms. The ballast controls content rates of each of the sets per unit time; detects a rotation synchronization signal for a color wheel; applies a synthesized current waveform in accordance with the synchronization signal and the content rates to a high pressure discharge lamp; and detects a lamp voltage. A period of each of the first and second sets equals to one rotation of the color wheel. The number of inversions of the second set is larger than that of the first set. The content rate of the second set is set to R% when the lamp voltage exceeds a value V, and the content rate of the second set is set to R% when lamp voltage falls below a value V'.

A start assisting light source is configured such that it can be mounted simply and reliably at a position capable of efficiently radiating UV-light for enhancing the starting performance of a high pressure discharge lamp to discharge chamber without being heated to a high temperature during lighting of the lamp and also adopted to a simple constitution of not increasing the manufacturing cost. A start assisting light source includes an airtight vessel filled with a rare gas and a pipe member that penetrates through the vessel is mounted to an electrode lead which protrudes from the end face of an electrode seal portion secured to a bottom hole of the concave reflector by inserting the electrode lead through the pipe member.

Light source device

Provided is a manufacturing method to prevent devitrification of a bulb in a high pressure discharge lamp used for a projector. The method is for manufacturing a high pressure discharge lamp which uses, as a light source, a bulb made of fused quartz and including a tungsten electrode, and which is horizontally installed when the lamp is driven for actual use. The method includes the step of initially driving the bulb with an optical axis thereof being set horizontally before the high pressure discharge lamp is shipped. In the initial driving step, the rotation angle around the optical axis of the bulb is offset by 45&#xb0; or more and 135&#xb0; or less relative to the rotation angle around the optical axis of the bulb when the lamp is driven for actual use.

Method for manufacturing high pressure discharge lamp

Growing community of inventors

Gyoda, Japan

Makoto Ohkahara