Abstract: 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/mm3 mercury, a rare gas with argon as the main component, and 2×10?4 ?mole/mm3 to 7×10?3 ?mole/mm3 bromine by meeting the following conditions when feeding a direct current of 5 mA between the electrodes and a glow discharge produced: 1.0×10?4?b/a?1.2×10?1??Condition (1) c/a?1.4×10?1??Condition (2) d/a?1.2×10?2??Condition (3) e/a?1.4×10?2??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 C2 with a wavelength of 517 nm, and e is the emission intensity of CH with a wavelength of 431 nm.

Abstract: 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/mm3 of mercury, a rare gas, and a halogen in the range from 1×10−6 &mgr;mole/mm3 to 1×10−2 &mgr;mole/mm3, 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.

Abstract: The present invention provides an injection molding die having a simplified valve gate and simplified attachment structures for the valve gate. The die includes: a first die 4 with a gate 7; a second die 20 forming, together with the first die 4, a molding cavity 23 that communicates with the gate 7; a manifold 10 containing a molding material supply path 12 communicating with the gate 7; a thermal insulation space 16 disposed between the first die 4 and the manifold 10; and a valve gate 24 disposed between the first die 4 and the manifold 10 opening and closing the gate. The valve gate 24 includes: a valve pin 25 passing through the first die 4 and the manifold 10 and opening and closing the gate 7; a sealing member 27 mounted on the manifold 10 where the valve pin 25 passes through and providing a seal between the manifold 10 and the first die 4; and a heater 29 heating the manifold 10.

Abstract: 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/mm3 of mercury, rare gas and halogen in the range from 10−6 &mgr;mole/mm3 to 10−2 &mgr;mole/mm3, 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.

Abstract: 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.

Abstract: The present invention provides an injection molding die having a simplified valve gate and simplified attachment structures for the valve gate. The die includes: a first die 4 with a gate 7; a second die 20 forming, together with the first die 4, a molding cavity 23 that communicates with the gate 7; a manifold 10 containing a molding material supply path 12 communicating with the gate 7; a thermal insulation space 16 disposed between the first die 4 and the manifold 10; and a valve gate 24 disposed between the first die 4 and the manifold 10 opening and closing the gate. The valve gate 24 includes: a valve pin 25 passing through the first die 4 and the manifold 10 and opening and closing the gate 7; a sealing member 27 mounted on the manifold 10 where the valve pin 25 passes through and providing a seal between the manifold 10 and the first die 4; and a heater 29 heating the manifold 10.

Abstract: 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/mm3 of mercury, the outside surface of the glass reflector is surrounded by a metallic component.

Abstract: 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/mm3 of mercury, the outside surface of the glass reflector is surrounded by a metallic component.

Abstract: 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/mm3, rare gas, and at least one halogen, and in which the wall load is at least equal to 0.8 W/mm2, the amount of mercury added being fixed in a range from 2×10−4 to 7×10−3 &mgr;mole/mm3, 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.

Abstract: 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.

Abstract: 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.