Mitsubishi Denki Kabushiki Kaisha

Yoshinori Anzai

Takeo Saikatsu

Toshiro Kajiwara

Michihiro Tsuchihashi

Katsuo Murakami

Hiroyoshi Yamazaki

Hiroshi Ito

Takashi Osawa

Takehiko Sakurai

Yoshiji Minagawa

Seishiro Mitsuhashi

Yujiro Kamano

Goroku Kobayashi

Kazutoshi Ishikawa

Masato Saito

Hiroshi Yamazaki

Hiromi Adachi

Makoto Yamanoshita

Mitsuoki Otani

Shunichi Morimoto

Takao Saikatsu

A green-light-emitting rare gas discharge lamp includes a glass tube filled with at least one selected from the group consisting of xenon, neon, helium, argon and krypton as a rare gas capable of emitting vacuum ultraviolet rays of a wavelength of not more than 200 nm, and includes on an inner surface of the glass tube a layer of a green-light-emitting phosphor having terbium-activated yttrium silicate, whereby it is intended to obtain enhanced performance as a green-light-emitting light source and to put the discharge lamp to practical use as a green-light-emitting light source for office automation equipment, for instance.

Green-light-emitting rare gas discharge lamp

The invention provides a rare gas discharge fluorescent lamp device which is long in life and high in brightness and efficiency. The lamp device comprises a rare gas discharge fluorescent lamp including a glass bulb having xenon, argon or krypton gas enclosed therein, a fluorescent layer formed on an inner face of the bulb, and a pair of electrodes located at the opposite ends of the bulb. A pulse-like voltage wherein the ratio of an energization period with respect to one cycle is higher than 5% but lower than 70% (xenon or krypton gas) or 80% (argon gas) and the energization period is shorter than 150 .mu.sec is applied between the electrodes of the lamp. Such pulse-like voltage is produced from a circuit including a dc power source, a pulse signal source, and a switching element for controlling application of a voltage of the dc power source or such voltage boosted by a boosting transformer or a resonance circuit. Where the negative electrode includes a filament coil, a rectifying element is connected between the electrodes of the lamp for allowing pre-heating of the filament coil.

Rare gas discharge fluorescent lamp device

A discharge lamp comprises a substantially straight glass bulb having a discharge gas charged therein and an electrode provided at each longitudinal end portion of the bulb on the outer surface thereof. A high frequency voltage is applied across the electrodes of the discharge lamp. Each end portion has an outer surface area per unit length of the bulb larger than that at light emitting portion of the bulb. The outer surface area may be uneven or in the shape of ridges and furrows at the end portions to create a large surface area, the electrodes being configured to the ridges and furrows. The end portions may have a larger diameter than that of the light emitting portion of the bulb so that they have a larger surface area contacting with the bulb. Each of the electrodes may have a narrow belt-shaped elongate portion on the outer surface of the bulb extending longitudinally within toward the middle portion, thereby allowing use of a lower discharge voltage. The fluophor may be applied to the inner surface area except the surface opposite the electrodes.

Discharge lamp with external electrodes

Hot-cathode discharge fluorescent lamps filled with low pressure rare gas being discharge fluorescent lamps filled with low pressure rare gas with a tube diameter of 16 mm or less provided with a pair of electrodes on both ends of a glass tube which operate as a hot-cathode in a stable discharge condition, having a fluorescent material layer on the inside surface of the bulb, filled with a luminous gas therein, and which is illuminated with irradiation from discharge in the luminous gas, in which at least one gas of He, Ne, Ar, and Kr are filled in addition to Xe as the luminous gas in an amount that the percentage of additional gas volume to total gas volume exceeds 50%.

Hot-cathode discharge fluorescent lamp filled with low pressure rare gas

The invention is concerned with an illuminator to radiate light rays in the near-infrared region, and a near-infrared ray image pick-up device which irradiates the near-infrared light radiated from this illuminator onto an object to be pictured, and captures light reflected from the object for image pick-up. By constructing the illuminator with an electric discharge lamp and a filter which removes the visible region and permit the near-infrared region to pass therethrough out of light rays radiated from this electric discharge lamp, there can be provided a near-infrared ray radiation illuminator having a high efficiency and low deterioration characteristic. And, at the same time, by constructing a near-infrared ray image pick-up device with this near-infrared ray radiation illuminator and an image pick-up device which captures reflected light of the near-infrared ray radiated from the illuminator to be irradiated onto the object for the image pick-up, the image pick-up can be done without notice of a human being, whereby, when the device is used as a crime-preventing monitoring device, the monitoring of an intruder can be done perfectly, and, when it is used as a visitor congnition device, there is no disagreeable feeling on the part of the visitor by his being dazzled by illuminating light or his knowledge of being pictured by the device.

Near-infrared ray radiation illuminator and near-infrared ray image

An illuminator for cultivating a plant by a discharge lamp excited by the output of a high frequency power source by utilizing photosynthetic mechanism. The output power of the high frequency power source is controlled to high and low powers by a bright and dark controller to alternatively supply the high and low powers to the discharge lamp in predetermined periods.

Illuminator for cultivating plant

A low-pressure mercury vapor discharge lamp comprises a tubular bulb having an inside diameter of from 22 mm to 35 mm, an electrode-to-electrode distance of from 400 mm to 1,200 mm, and an inner surface coated with a phosphor. A rare gas including Kr and a mercury vapor source are sealed in the bulb, which is energized by an igniting device having a high-frequency power supply connected to a DC power supply for generating a substantially sinusoidal high-frequency output voltage, and a quiescent period generator connected to the high-frequency power supply and including a switch 17 turned on and off at least once during each half cycle to provide a quiescent period and thereby produce a substantially square wave high-frequency output voltage having rise and fall times of 2 .mu.s or less.

Low-pressure mercury vapor discharge lamp

A lighting circuit for an electric discharge lamp according to the present invention is constructed in such a way that a switching device is provided at an output terminal of a high frequency inverter which produces a substantially sinusoidal output voltage, and that, by controlling this switching device, an output to the low pressure electric discharge lamp is stopped at the rising part of the abovementioned output voltage in its half cycle, while the output is supplied to the low pressure electric discharge lamp at the voltage level in the vicinity of the maximum instantaneous value thereof. By use of the high frequency inverter of a smaller capacity and less radio noise than those in the conventional device, the operating efficiency of the low pressure electric discharge lamp can be increased.

Lighting circuit for electric discharge lamp

A low pressure discharge lamp has a nonlinear arc path formed by a partition in a lamp envelope wherein the lamp envelope is polyhedral and the partition is fixed to the corners of said polyhedron lamp envelope.

Low pressure discharge lamp with polygon shaped envelope

A lamp primarily containing neon gas is supplied with alternating electrical power at a frequency of not less than 5 kHz. The discharge current is determined on the basis of the gas pressure such that no striations occur. If necessary, getter means including a metal element belonging to the second, third, fourth or fifth periodic group are provided near each electrode, oriented so as not to interfere with any electron emissions from the lamp electrodes.

Low pressure inert gas discharge device

A fluorescent lamp having excellent color rendering property and high luminous efficiency comprises a fluorescent layer coated on an inner surface of a discharge tube. The fluorescent layer mainly comprises a first fluorescent material having-emission peak in a range of wavelength of 480 to 490 nm which is an alkaline earth metal boron phosphate activated by a divalent europium compound having the formula

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Kamakura, Japan

Yoshinori Anzai