Mitsubishi Denki Kabushiki Kaisha

Michihiro Tsuchihashi

Masato Saito

Ryo Suzuki

Keiji Watanabe

Osamu Myodo

Makoto Yamanoshita

Hidetoshi Katsura

Koichiro Maeyama

Yoshinori Anzai

Toshiro Kajiwara

Katsuya Otani

Takeo Saikatsu

Keiji Fukuyama

Ryohei Itatani

Hiroyoshi Yamazaki

Yoshiji Minagawa

Masatoshi Ryohko

Yutaka Murai

Yoshinori Takai

Keiichi Baba

Yusaku Matsushima

Heiji Watanabe

Takao Saikatsu

Yasushi Uchida

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

Metal 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

In a metal vapor discharge lamp for operating it by high voltage generated in the actuation of a heat sensitive switch means in an outer bulb, a relatively low pressure of a sealed gas or mercury is sealed in the outer bulb to operate the heat sensitive switch means in the gas atmosphere to control the surge voltage to a desired degree whereby the discharge lamp is operated without failure and the insulation breakdown of a ballast and an operation circuit is prevented.

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 metal vapor discharge lamp including an arc tube including an outer bulb and having at least an oxide crystal incorporated in the outer bulb, with a starting aid equipped on the outer circumference of said arc tube; at least one end of said arc tube having a heat insulator to keep the end warm, and a rare gas enclosed at 100 Torr or above together with at least sodium and mercury in said arc tube.

Metal vapor discharge lamp with heat insulator and starting aid

A high pressure discharge lamp in which the restriking voltage and time are significantly decreased. A pair of electrodes are sealably disposed in a tube containing an appropriate amount of mercury. Means is provided for heating at least one of the electrodes for starting the lamp if it has been recently turned off and the mercury vapor pressure inside the tube is high. The heating means is preferably a filament made of a thermally stable material. One terminal of the filament may be connected to one of the electrodes.

High pressure discharge lamp

A discharge lamp comprises an arc tube for high pressure discharge and a discharge gap for discharging until restarting the arc tube. The discharge gap being electrically connected in parallel to the arc tube in an outer bulb. A normally opened temperature responsive switch means is connected in series to the discharge gap and a series of the discharge gap and the temperature responsive switch means is connected in parallel to the arc tube.

Discharge lamp and lighting equipment

A metal vapor discharge lamp comprises main electrodes and an auxiliary electrode in an arc tube to initiate the discharge between the main electrode and the auxiliary electrode at the initiation of the operation and then to result the discharge between the main electrodes by disconnection of the auxiliary electrode by a bimetallic switch means. A second bimetallic switch means which delays the operation from that of the first bimetal, is connected in series to the first bimetallic switch means so as to discharge in a circuit formed in an outer bulb to break a part of the circuit and to prevent a ballast from overheating.

A lighting equipment comprises a high pressure metal vapor discharge lamp having a lamp voltage of 145 to 180 V actuated by a lag type ballast supplied with a voltage of lower than 220 V or a high pressure metal vapor discharge lamp having a lamp voltage of 150 to 200 V actuated by a lag type ballast supplied with a voltage of higher than 220 V whereby a consumed power is reduced in comparison with the conventional lighting device.

Lighting equipment

A discharge lamp comprises a high pressure arc tube for high pressure and a low pressure arc tube for low pressure which is electrically connected in parallel to said high pressure arc tube in an outer tube. A lighting equipment comprises a high pressure arc tube for high pressure discharge and a low pressure arc tube for low pressure which is electrically connected in parallel to said high pressure arc tube; and a high frequency lighting starter having 1 KHz to 100 KHz for starting the discharge of said high pressure arc tube.

Beautifully and balanced colored shadows can be imparted by arranging an R unit for light sources for yellow to red; a G unit for light sources for green and a B unit for light sources for violet to blue with each predetermined space wherein each unit comprises a plurality of light sources in each group adjacent each other.

Method of lighting for colored shadows

Beautifully and balancedly colored shadows can be imparted by arranging color lamps in three R, G and B groups, illuminating an object to obtain colored shadows of the object to give the ratios of illuminances by the color light lamps; ##EQU1## in a range surrounded by the following ratios of j-k-l-m-n-e-f-j in the triangular coordinate of FIG. 2 wherein I.sub.R designates an illuminance by only the lamp in the R group; I.sub.G designates an illuminance by only the lamp in the G group and I.sub.B designates an illuminance by only the lamp in the B group.

Beautifully and balancedly colored shadows can be imparted by arranging color lamps in three R, G and B groups and a white light lamp for white light (W group), illuminating objects to obtain colored shadows of the objects, giving the ratio of illuminance by the white light lamp: ##EQU1## wherein I.sub.W designates an illuminance at the part illuminated by only the white light lamp, and also the illuminance in the shadows to the lights of the lamps of the three R, G and B groups; and I.sub.R designates an illuminance at the part illuminated by only the lamp of the R group in the shadow of the object to both of the lights of the lamps of the G group and the B group; I.sub.G designates an illuminance at the part illuminated by only the lamp in the G group in the shadow of the object to both of the lights of the lamps in the R group and the B group and I.sub.B designates an illuminance at the part illuminated by only the lamp in the B group in the shadow of the object to both of the lights of the lamps in the R group and the G group.

Beautifully and balanced colored shadows can be cast of an object by using a lamp for emitting colored light in the range yellow to red, a lamp for emitting green colored light and a lamp for emitting colored light in the range violet to blue to give intensity ratios of illumination in the ranges of

Growing community of inventors

Kamakura, Japan

Michihiro Tsuchihashi