Ushio Denki Kabushiki Kaisha

Yoshihiro Horikawa

Akihiko Sugitani

Takanori Samejima

Takashi Ito

Kiyoyuki Kabuki

Yoshio Okazaki

Hiroto Sato

Takuya Tsukamoto

Takuya Tukamoto

Masashi Okamoto

Yoshikazu Suzuki

Tatsushi Igarashi

Mitsuo Narita

Toru Kontani

Takahiro Toma

Kazuhiro Yoshida

Takayuki Kozakura

Kentaro Fujita

Nobuhiko Sugihara

Toru Nishikubo

Tetsuya Ozawa

Noriko Nishiaki

Senga Takehito

Masataka Kawaguchi

Motoko Uramoto

Dan Masashi

The purpose of the present invention is to make it possible to output stable light by optimizing the wavelength conversion efficiency in a wavelength conversion element without employing an optical detection device such as a photo diode in a laser light source device. A fundamental light wave emitted from a semiconductor laser () is wavelength converted by a wavelength conversion element () and is emitted therefrom. A lighting circuit () supplies electric power for the aforementioned semiconductor laser () to turn on the semiconductor laser (). A control unit () controls the operation of the device while controlling the amount of power supplied to a heater means () such that the wavelength conversion element () reaches a temperature at which optimum wavelength conversion efficiency is acquired. The temperature detected by a temperature detection means (Th) is input to the control unit (), and the control unit () defines the temperature of the wavelength conversion element () at which the maximum amount of power is supplied to the heater means () as a set temperature at which the optimum wavelength conversion efficiency is acquired, and performs feedback control of the temperature of the wavelength conversion element () so that the temperature of the wavelength conversion element () reaches the aforementioned set temperature by controlling the amount of heat supplied from the heater means ().

Laser light source apparatus and temperature control method of wavelength conversion element in laser light source apparatus

The fundamental wave light emitted from a semiconductor laser is converted in wavelength by a wavelength conversion element and emitted therefrom. A lighting circuit lights the semiconductor laser, and a temperature control unitcontrols the amount of electric power supply to a heater so that the temperature of the wavelength conversion element turns into temperature at which the wavelength conversion efficiency thereof becomes optimal. When a state where the amount of electric power supply of the heater is lower limit or below continues for a predetermined period or longer, the hang-up suppressing unit, or when duration time in a state where the temperature of the wavelength conversion element is higher than the control target temperature becomes higher than a constant value, laser lighting current is decreased by a preset amount, thereby recovery from a high temperature hang-up state performed.

Laser light source apparatus

In a light source device, in each division of an image frame, two or more of the color lights X, Y and Z (e.g., red, green and blue) can be projected simultaneously. Each of the color lights X, Y and Z is divided into two in terms of time so that synthesized light of one group of division color lights enters a first spatial modulation element. Synthesized light of another group of division color lights enters a second spatial modulation element, whereby gradation of each color light in each of the first and second spatial modulation elements is controlled.

Light source device

In a light source device, that obtains high light usage efficiency by projecting simultaneously two or more of three primary color lights X, Y and Z. Moreover, each color light X, Y and Z is divided into two in terms of time so that p-wave and s-wave linear polarization lights are formed, such that the synthesized light of the p-wave linear polarization lights enters a first spatial modulation element and the synthesized light of the s-wave linear polarization lights enters a second spatial modulation element to permit gradation control of each color light.

A discharge lamp lighting apparatus for lighting a discharge lamp, comprises an inverter which reverses a polarity of an output voltage and applies alternating voltage to the discharge lamp, and an inverter control circuit which generates an inverter control signal defining a polarity reversal operation of the inverter, based on a polarity reversal timing signal, wherein when the number of polarity reversals in one cycle of the polarity reversal timing signal is even, the inverter control circuit intermittently performs a first operation in which successive pulse-like part of the polarity reversal operation based on the polarity reversal timing signal is disregarded by odd number of times.

Discharge lamp lighting apparatus and projector

An electrode for an extra-high pressure discharge lamp, comprises large diameter portion which is symmetrical with respect to an axis of the electrode, a small diameter portion connected to the large diameter portion, wherein the large diameter portion is connected to the small diameter portion through an outer surface portion of the electrode, wherein a stripe lines like pattern portion, extending along an electrode axis direction, is formed on a portion to be brought in contact with glass of a lamp, and wherein unevenness is formed over an entire circumference of the electrode in a cross sectional view of the electrode taken along a direction perpendicular to the electrode axis direction.

Electrode and extra-high pressure discharge lamp using the same

Optical apparatus with a discharge lamp and a concave reflecting mirror, the concave reflecting mirror has a front elliptical reflecting mirror portion, a middle spherical reflecting mirror portion, and a rear elliptical reflecting mirror portion; the relationship between an angle &#x3b1; between a virtual tangential line VTL, which runs from the center position between the electrodes to the outer surface of the electrode positioned towards the neck of the concave reflecting mirror, and the beam axis Z and an angle &#x3b2; between a virtual straight line VSL, which runs from the center position between the electrodes to the boundary position between the middle spherical reflecting mirror portion and the rear elliptical reflecting mirror portion, and the beam axis Z is &#x3b2;&#x3e;&#x3b1;; and the relationship between the volume V of the electrode E(mm) and the wattage (P) meets the condition, 0.07&#xd7;EXP(0.014&#xd7;P)&#x3c;V.

Optical apparatus

Process for producing a discharge lamp having a silica discharge vessel with an emission space in which there is a pair of electrodes at least 0.15 mg/mmof mercury, argon (Ar), and halogen by measuring the relation b/a1 between the emission intensity aof argon (Ar) at a wavelength of 668 nm and the emission intensity b of OH radicals at a wavelength of 309 nm in a state of glow discharge of the discharge lamp; supplying hydrogen into the discharge vessel of the discharge lamp; measuring the relation c/abetween the emission intensity aof argon (Ar) at a wavelength of 668 nm and the emission intensity c of OH radicals at a wavelength of 309 nm in the state of glow discharge of the discharge lamp; and fixing the difference c/a&#x2212;b/aat a value in the range of 0.001 to 15.

Discharge lamp with a discharge filling having a measured emission intensity of argon to OH radicals and method of manufacturing the same

A short-arc ultra-high pressure mercury lamp in which the change in the shape of the electrodes can be suppressed and a stable arc discharge can always be produced is achieved in an arrangement in which, in the silica glass arc tube, there is a pair of opposed electrodes with a distance between them of at most 2 mm and the tube is filled with at least 0.15 mg/mmof mercury, a rare gas, and a halogen in the range from 1&#xd7;10&#x3bc;mole/mmto 1&#xd7;10&#x3bc;mole/mm, by at least one of the electrodes having a melt part formed toward the electrode tip by winding the electrode rod with a coil and by melting the part of the coil oriented towards the electrode tip at least in the area of its surface. A part of the coil located away from the electrode tip is unmelted and the base point side area of the coil facing away from the electrode tip is rounded and does not have sharp edges.

Short arc ultra-high pressure mercury lamp with rounded end faces of coil tips and process of producing such a lamp

An ultra-high pressure mercury lamp is provided in which the disadvantage caused by projections formed on the electrode tips during operation can be eliminated. This is achieved by an arrangement in which a silica glass arc tube, filled with at least 0.15 mg/mmof mercury, rare gas and halogen in the range from 10&#x3bc;mole/mmto 10&#x3bc;mole/mm, includes a pair of opposed electrodes spaced a distance of at most 2 mm. Additionally, at least one of the electrodes includes a part with a greater diameter which is formed on the electrode shaft using a melting process, a projection which is formed by the tip of the electrode shaft, and a part with a decreasing diameter which extends from the part with the greater diameter in the direction toward the projection.

Short arc ultra-high pressure mercury lamp and method for the production thereof

A discharge lamp which maintains a high lumen maintenance factor even when operated for a long time is obtained in a discharge lamp which has a silica glass discharge vessel and a pair of opposed electrodes in the discharge vessel and in which the discharge vessel is filled with at least 0.15 mg/mmmercury, a rare gas with argon as the main component, and 2&#xd7;10&#x3bc;mole/mmto 7&#xd7;10&#x3bc;mole/mmbromine by meeting the following conditions when feeding a direct current of 5 mA between the electrodes and a glow discharge produced:1.0&#xd7;10&#x2266;1.2&#xd7;10&#x2003;&#x2003;Condition (1)&#x2266;1.4&#xd7;10&#x2003;&#x2003;Condition (2)&#x2266;1.2&#xd7;10&#x2003;&#x2003;Condition (3)&#x2266;1.4&#xd7;10&#x2003;&#x2003;Condition (4)where a is the emission intensity of the argon with a wavelength of 668 nm, b is the emission intensity of OH with a wavelength of 309 nm, c is the emission intensity of hydrogen (H) with a wavelength of 656 nm, d is the emission intensity of Cwith a wavelength of 517 nm, and e is the emission intensity of CH with a wavelength of 431 nm.

Discharge lamp with specific amounts of halogen, oxygen, hydrogen and carbon

A reflector for a high pressure discharge lamp device including a metallic component such that when the lamp is damaged the reflector is not broken or when the reflector is broken, spraying of lamp fragments can be effectively prevented. In the reflector for a high pressure discharge lamp device, the glass reflector houses a discharge lamp of the short arc type in which the discharge vessel is filled with greater than or equal to 0.15 mg/mm of mercury, the outside surface of the glass reflector is surrounded by a metallic component.

Reflector for a high pressure discharge lamp device

A high pressure mercury lamp in which formation and spreading of milky opacification in the fused silica glass forming the discharge vessel can be advantageously prevented, and thus a rapid decrease of screen illuminance prevented, when it is used as the light source of a liquid crystal projector and the like by, in a high pressure mercury lamp in which a discharge vessel of fused silica glass contains a pair of opposed tungsten electrodes, mercury in an amount that is at least equal to 0.16 mg/mm,, rare gas, and at least one halogen, and in which the wall load is at least equal to 0.8 W/mm,, the amount of mercury added being fixed in a range from 2&times;10,to 7&times;10,&mgr;mole/mm,, and/or the at least one halogen being in the form of a carbonless halogen compound, and/or the average OH radical concentration in an area of a wall of the discharge vessel at a depth of 0.2 mm from an inner surface of the wall of the discharge vessel being at most 20 ppm.

High pressure lamp with specific amount of mercury, halogen and wall loading

A high pressure mercury lamp with an extremely high mercury vapor pressure and extremely high tube wall load in which the arc during operation is advantageously stabilized is achieved in a high pressure mercury lamp having a discharge vessel of fused silica glass which contains a pair of opposed tungsten electrodes, mercury in an amount at least equal to 0.16 mg/mm.sup.3 and a rare gas, and in which the discharge tube has a tube wall load at least equal to 0.8 W/mm.sup.2, by at least one metal halide with a metal having an ionization potential that is at most 0.87 times as high as the mercury ionization potential being added to the discharge tube in a range of from 2.times.10.sup.-4 to 7.times.10.sup.-2 .mu.mole/mm.sup.3.

High pressure mercury lamp

A metal halide lamp with a distance of less than 3.0 mm between the electrodes, in which in the hermetically sealed portion no cracks occur, which can be produced without difficulty, and which enables advantageous operation is achieved with a halide lamp in which an arc tube made of quartz glass contains a cathode and an anode spaced from each other at a distance of less than or equal to 2.9 mm together with mercury and metal halides, and which is operated with a nominal wattage range of from 100 to 400 W using direct current, by causing the ratio D/H to be greater than or equal to 1.9 when D is the maximum inside diameter in millimeters in a direction which orthogonally intersects the axial direction of the electrodes in the discharge space and H is the length of the cathode projecting within the discharge space, also in millimeters.

Growing community of inventors

Hyogo, Japan

Yoshihiro Horikawa