Mitsubishi Denki Kabushiki Kaisha

Agency of Industrial Science and Technology

Haruhiko Nagai

Kenyu Haruta

Yukio Sato

Hitoshi Wakata

Hajime Nakatani

Masao Hishii

Mitsuo Inoue

Masaaki Tanaka

Akihiro Suzuki

Toshimasa Tomoda

Yasuhito Myoi

Fumio Suzuki

Yoshibumi Minowa

Yoshisuke Ohtsuru

Akihiko Iwata

Kenji Kimura

Tomohiro Sasagawa

Toshio Ito

Kenichi Yasuda

Hiroshi Kawamura

Shuichi Fujikawa

Teruo Miyamoto

Toshiyuki Yoneda

Shuji Iwata

Norikazu Tabata

Masanori Kojima

Kenji Samejima

Takayoshi Semasa

Kazuaki Matoba

Hiroshi Mitsuda

Naoki Kawamoto

Tadao Minagawa

Yoshihiko Yamamoto

Toshio Itoh

Kenji Maeno

Takio Okuda

Toyomi Ohshige

Kenji Tatsumi

Taketoshi Takemura

Yoshifumi Matsushita

Shinji Murata

Isamu Tanakura

Miki Fukada

Hisao Koizumi

Hiromi Kaneko

Hiroyuki Mukumoto

Tsunehiro Imamura

Takashi Eura

Shungo Tsuboi

Yuito Kimura

Kou Nishino

Toshimitsu Akiba

Kouzaburo Shibayama

Akio Nagai

Hideki Kita

A plurality of liquid crystal modules is vertically and horizontally arranged, each of which is supplied light by a light source via optical fibers. A screen can be wound up at a cabinet. An image from each of the plurality of liquid crystal modules does not interfere one another because a light shielding board is installed.

Image display system

A dichroic mirror for reflecting red light for optical separating and a dichroic mirror for reflecting red light for optical synthesizing are installed on the same plane in an image generating apparatus of the present invention. In addition, a dichroic mirror for reflecting blue light for optical separating and a dichroic mirror for reflecting blue light for optical synthesizing are installed on the same plane. Accordingly, a compact configuration can be realized. Since a main reflecting mirror is a rotating elliptic mirror and a lamp is located on a focus or around the focus, a lighting equipment which irradiates conic luminous flux can be realized.

Method and apparatus for image generation

At least two types of preionization systems are provided at a backside of one of a pair of primary electrodes which are disposed in a spaced opposed relation with respect to each other for causing a large area, spatially uniform main discharge in a laser gas therebetween. This improves efficiency and stability in laser oscillations under repeated operations at a high rate of tens to hundreds of shots per second. In addition, without using the laser output power, the preionization timing is controlled such that an optimal preionization timing is realized. The optimal preionization timing is determined on the basis of a minimum discharge starting voltage between the primary electrodes or a minimum required time from the time of applying a high voltage between said first and second primary electrodes until the time the main discharge commences.

Discharge excitation gas laser apparatus

A switch device used for a laser device, includes series-parallel connected switch elements or modules. The switch elements or modules are simultaneously turned on by trigger signals from trigger circuits. The transmission lines for connecting the trigger circuits to respective switch elements are equal to one another in length. A protecting circuit is provided for the switch elements, and indicators are provided for indicating the shortcircuit of the switch elements. In the switch device, the number of wires for the switch elements is made small and heat generated from the switch elements is effectively radiated. The modules are easily stacked, and firmly connected to a control unit for controlling the switch elements. A discharge excited laser device using the switch device has a high efficiency and a long lifetime and is reliable.

Switch device for laser

At least the opposing surface portions of the main electrodes of an excimer laser device are covered with materials which are resistive to chemical etching than nickel. The etching resistive material may be a platinum based alloy containing rhodium, ruthenium, iridium, or osmium; a nickel based alloy containing gold, platinum, rhodium, ruthenium, iridium, or osmium; or rhodium, ruthenium, iridium, or osmium. Thus, an excimer laser device is realized by which the lives of the electrodes and the laser gas are prolonged.

Excimer laser device

A discharge pumping circuit of spiker/sustainer type for the Excimer laser oscillator, wherein spiker unit is isolated from the sustainer unit by a switching device such as a magnetic isolator is disclosed. In the pumping circuit, the switching device shifts from its OFF state to its ON state, during the process of charging a spiker capacitor, before its terminal voltage reaches a voltage which initiates the discharge, and a sharp-rise pulse voltage is applied by a transfer of electric charge from said sustainer capacitor to said spiker capacitor, to initiate the discharge for the pumping. In another discharge-pumping circuit which also has a means for preionizing the laser gas, the timing for the preionization is set to start after the initiation of charging the sustainer capacitor and before the initiation of charging the spiker capacitor in a polarity opposite to that of the sustainer capacitor, and is controlled for maintaining the discharge initiating voltage constant for the repetition frequency. In another discharge-pumping circuit, a power source for charging the sustainer capacitor is structured to include a magnetic pulse compression circuit to reduce the stress on a high voltage switch such as a thyratron in the circuit to realize an excellent performance, a long service life and a high reliability.

Laser oscillator circuit

Method of stabilizing laser wavelength and laser device with stabilized

A laser wavelength is stabilized by deriving a portion of laser beam emitted from a wavelength variable laser oscillator, spectroscopically processing the laser beam portion by means of a wavelength monitor mechanism, measuring a spatial intensity distribution of the spectroscopically processed beam portion, spectroscopically processing light having a specific wavelength and measuring a spatial intensity distribution thereof, analyzing the measured spatial intensity distribution of the spectroscopically processed beam portion on the basis of the measured spatial intensity distribution of the spectroscopically processed light having the specific wavelength, and controlling wavelength of the laser oscillator according to a result of the analysis.

Laser wavelength stabilization

A discharge excitation type short pulse laser device is provided with a preliminary ionization circuit, the effeciency of preliminary ionization of which is remarkably improved. The laser device comprises a main discharge circuit including first and second main electrodes which are confronted with each other in a laser medium, main discharge capacitor means for storing energy for main discharge, and a discharge starting high voltage switch; and a preliminary ionization circuit connected to said high voltage switch, said preliminary ionization circuit including a discharging gap for preliminary ionization, a preliminary ionization capacitor and an inductance.

Discharge excitation type short pulse laser

The present invention relates to excimer laser equipment which is one kind of gas laser, and in particular to a rare gas-halide excimer laser using rare gases and halogens as laser media, and adapted to control the concentration of halogens contained in laser media therewithin on the basis of the result of the measurement of the concentration of halogens in the laser media which is being used for the oscillation of laser rays therein, whereby the stabilized oscillation of the laser is always possible.

Excimer laser equipment

A discharge excitation type short pulse laser device which is constructed with first and second main electrodes disposed in confrontation with the direction of the laser beam axis as their longitudinal direction, an auxiliary electrode provided on the rear surface part of the second main electrode and opposed to the second main electrode through the dielectric member, a pulse circuit for applying a pulse voltage across the first and second main electrodes, and a circuit for applying a voltage across the auxiliary electrode and the second main electrode, the circuit forming a part of the pulse circuit, or being independent of the pulse circuit, wherein the second main electrode is made of an electrically conductive material having a plurality of apertures therein, the second main electrode and the dielectric member are disposed in tight adhesion each other, and the second main electrode is thinly formed to enable creeping discharge to be produced on the surface of the dielectric member, thereby distributing electrons to be the seed for the main discharge to be generated across the main electrode.

Discharge excitation type short pulse laser device

A lateral excitation type gas laser device having a small size and high output. An anode and a cathode are arranged opposite one another with a flow of laser gas therebetween. A high DC voltage is applied between the anode and cathode to cause a glow discharge therebetween. A dielectric electrode is disposed in the flow of laser gas upstream of the anode and cathode, and a high frequency high voltage is applied between the dielectric electrode on one hand and the anode and cathode on the other for causing a silent discharge therebetween. The dielectric electrode has a diameter of 3 mm&lt;D&lt;d/2, where D is the diameter of the dielectric electrode and d is the length of the gap between the anode and cathode. The dielectric electrode is disposed in a region defined by 0.ltorsim.l.sub.1 .ltorsim.2d and 0.ltorsim.l.sub.2 .ltorsim.d, where l.sub.1 is the distance in the direction of the laser gas flow between the dielectric electrode and the cathode and l.sub.2 is the distance between the dielectric electrode and the anode.

Lateral excitation type gas laser

A gas laser apparatus having an anode and a cathode for imparting a glow discharge to a stream of laser gas in response to a high d.c. voltage, also includes a dielectric electrode positioned within said stream of laser gas between the anode and cathode for exciting a pulsed silent discharge of the laser gas in response to an a.c. high voltage power source that supplies a pulsed high a.c. voltage to said dielectric electrode. A pulsed large-current glow discharge is produced between the anode and cathode to thereby emit a large, pulsed laser output. The apparatus may also include controls for controlling the power of the silent discharge excited by the dielectric electrode to thereby control the laser output.

Gas laser apparatus

A high pressure transverse excitation type laser oscillator comprises a plane anode and a plurality of rod type cathodes to form glow discharge. Each cathode is covered with a cylindrical insulator having heat resistance except for a small discharge surface whereby the shift of the glow discharge caused by varying the pressure or the discharge current can be prevented to thus obtain stable glow discharge.

Transverse excitation type laser oscillator

An electrical discharge occurs between the anode and the cathode and the active gas such as CO.sub.2 between the two electrodes is excited to provide a laser beam. The laser beam thus provided is reflected repeatedly by a pair of reflection mirrors. The reflected laser beam is amplified while passing through the space where the discharge occurs, thus providing the function of a gas laser oscillator. Although the amplification that occurs in the discharge zone between the electrodes, considerable laser beam absorption takes place in the space between the reflection mirrors and the electrodes. In this space, the amount of operating gas such as CO.sub.2 is reduced, or the space is evacuated. Alternatively, the space is cooled by causing the gas therein to flow. A reduction in so-called laser beam absorption function is provided.

Laser oscillator

Growing community of inventors

Amagasaki, Japan

Haruhiko Nagai