Abstract: A method for producing a high pressure discharge lamp including a luminous bulb enclosing a luminous substance inside and a sealing portion for retaining airtightness of the luminous bulb, includes preparing a glass pipe for a discharge lamp including a luminous bulb portion that will be formed into a luminous bulb of a high pressure discharge lamp and a side tube portion extending from the luminous bulb portion; inserting a glass member constituted by a second glass having a softening point lower than that of a first glass constituting the side tube portion into the side tube portion, and then heating the side tube portion so as to attach the glass member and the side tube portion; and after the attachment step, heating a portion including at least the glass member and the side tube portion at a temperature higher than a strain point temperature of the second glass and lower than a strain point temperature of the first glass.

Abstract: A short arc mercury lamp includes a luminous bulb enclosing at least mercury as a luminous material and a pair of electrodes opposed to each other; and a pair of sealing portions for sealing a pair of metal foils electrically connected to the pair of electrodes, respectively. The electrode central axis of one of the pair of electrodes is dislocated from the electrode central axis of the other electrode. The shortest distance d (cm) between the head of one of the electrodes and the head of the other electrode is larger than the value of (6M/13.6&pgr;)1/3 when the total mass of the enclosed mercury is M (g).

Abstract: A high pressure discharge lamp includes a luminous bulb enclosing a luminous substance therein; and a sealing portion for retaining airtightness of the luminous bulb. The sealing portion has a first glass portion extending from the luminous bulb and a second glass portion provided at least in a portion inside the first glass portion, and the sealing portion has a portion to which a compressive stress is applied.

Abstract: A laser beam writing material having: silicon dioxide; and a titanium-containing compound fixed with the silicon dioxide and capable of being changed in color by irradiation with a laser beam; wherein when a color-changed portion in the laser beam writing material is formed by irradiation with the laser beam and exposed to the air at 600° C. for 30 minutes, contrast between the color-changed portion and a color-unchanged portion in the laser beam writing material is not lower than 0.60; a material for forming the laser beam writing material, having a mixture at least including the titanium-containing compound and an MQ resin; and a display body having a color-changed portion formed by irradiation with the laser beam in the laser beam writing material.

Abstract: A high-pressure discharge lamp is configured to regulate the relationship between the radius r (mm) of the tungsten rods forming the electrodes and the lamp current I (amperes) using the formula 1.5 ≤ I π · r 2 ≤ 9 when the ratio of the circumference of the circle to its diameter is expressed as &pgr;. The high-pressure discharge lamp suppresses early blackening, and achieves a long-life light source.

Abstract: A method for producing a high pressure discharge lamp unit including a high pressure discharge lamp set and fixed to a reflecting mirror includes the steps of detecting light released from a point-like light source and reflected at a reflecting surface of the reflecting mirror to determine a position for setting that is a position of the point-like light source in which the reflected light is substantially the maximum; identifying a predetermined position between electrodes of the high pressure discharge lamp; and matching the predetermined position to the position for setting.

Abstract: A high pressure discharge lamp includes a vessel made mainly of quartz including a luminous portion and side tube portions extending from both sides of the luminous portion; mercury enclosed in the luminous portion; a metal foil buried in each of the side tube portion; and an electrode rod, one end of which is connected to the metal foil and the other of which is extending to the luminous portion. The electrode rod has a surface area increase structure for increasing a surface area in at least a part of a portion buried in the side tube portion. A sealing portion glass containing at least one metal material selected from the group consisting of metals and metal oxides thereof is provided in a portion of the side tube portion including at least a part of the metal foil, a connection portion between the metal foil and the electrode rod and a part of the surface area increase structure.

Abstract: A short-arc high-pressure mercury vapor discharge lamp includes a pair of electrodes in an arc tube and encloses mercury, a rare gas, and so forth in the arc tube. The lamp is so constructed as to be operated at a lamp current of, for example, about 1.5 A or higher, or at a lamp voltage/lamp current ratio of about 37.5 (V/A) or lower. In addition, the distance between the electrodes, and the like are set so that the rated power per unit arc length P/d≧88 (W/mm) and the tube wall loading Pw (rated power P/internal surface area of the arc tube)≦1.0 (W/mm2). Thus, a lamp is constructed having, even with a relatively low lamp voltage, a high lamp power of, for example, 125 W or higher, having a short arc length and a high luminous flux per unit arc length, and furthermore being one in which damage to the arc tube does not occur.

Abstract: An image projector has a lamp unit 23 having a high-pressure mercury vapor discharge lamp 21 and a parabolic mirror 22. To the high-pressure mercury vapor discharge lamp 21, a driving system 24 applies an alternating voltage such that wandering of a cathode luminescent spot generated in the vicinity of a tip of each of the discharge electrodes of the high-pressure mercury vapor discharge lamp 21 is suppressed, the frequency being within the range of 20-42 kHz. This construction allows to prevent flicker in a projected image of a liquid crystal projector and the like, and therefore achieves high quality in the projected image.

Abstract: The present invention relates to a lamp device using a high-pressure vapor discharge lamp, particularly to an improvement for controlling the influence of the generation of heat, which accompanies an increase in lamp power and a reduction in the size of a reflector. A lamp device of the present invention comprises a discharge lamp having an arc tube enclosing luminescent materials and having a pair of opposing electrodes disposed therein and a pair of sealed portions extending from the arc tube; a reflector which reflects light radiated by the discharge lamp; a transparent member covering an open end of the reflector and accommodating the discharge lamp in a space between the transparent member and the reflector; and means for preventing an excessive temperature rise wherein the temperature rise of welded parts of wiring members electrically connected to the electrodes of the discharge lamp is restricted.

Abstract: A baking sheet, a baking printed sheet and a burned sheet obtained by the baking printed sheet are disclosed. The baking sheet comprises a printing sheet comprising an ink receiving layer in a sheet form, said ink receiving layer comprising a mixture of an inorganic powder and a silicon-containing binder and being located on a surface of the printing sheet, wherein said silicon-containing binder comprises trimethylsiloxysilicic acid or a polymer comprising monofunctional M units represented by the formula R3SiO— wherein R represents a compound group, and quadrifunctional Q units represented by the formula Si(O—)4.

Abstract: The present invention provides a long-life discharge lamp by removing the causes of lowering the service life of the discharge lamp owing to quartz glass constituting the discharge lamp and a gas sealed therein, and also provides a discharge lamp production method wherein the mixing of impurities affecting the service life of the discharge lamp is prevented. In the discharge lamp the content of hydrogen, oxygen and their compounds existing in the light-emitting portion is such that the maximum intensity of the light-emitting spectral intensities of the above impurities is {fraction (1/1000)} or less of the intensity of the main light-emitting spectrum of the noble gas when glow discharge occurs by supplying a current of 3 mA, and also the content of OH groups included in the quartz glass of the sealing portions is 5 ppm or less by weight.

Abstract: An image projector has a lamp unit 23 having a high-pressure mercury vapor discharge lamp 21 and a parabolic mirror 22. To the high-pressure mercury vapor discharge lamp 21, a driving system 24 applies an alternating voltage such that wandering of a cathode luminescent spot generated in the vicinity of a tip of each of the discharge electrodes of the high-pressure mercury vapor discharge lamp 21 is suppressed, the frequency being within the range of 20-42 kHz. This construction allows to prevent flicker in a projected image of a liquid crystal projector and the like, and therefore achieves high quality in the projected image.

Abstract: A discharge lamp includes a luminous bulb in which a luminous material is enclosed and a pair of electrodes are opposed in the luminous bulb; and a pair of sealing portions for sealing a pair of metal foils electrically connected to the pair of electrodes, respectively. At least one of the pair of metal foils has a twist structure.

Abstract: The present invention provides a long-life discharge lamp by removing the causes of lowering the service life of the discharge lamp owing to quartz glass constituting the discharge lamp and a gas sealed therein, and also provides a discharge lamp production method wherein the mixing of impurities affecting the service life of the discharge lamp is prevented. In the discharge lamp the content of hydrogen, oxygen and their compounds existing in the light-emitting portion is such that the maximum intensity of the light-emitting spectral intensities of the above impurities is {fraction (1/1000)} or less of the intensity of the main light-emitting spectrum of the noble gas when glow discharge occurs by supplying a current of 3 mA, and also the content of OH groups included in the quartz glass of the sealing portions is 5 ppm or less by weight.

Abstract: A discharge lamp includes a luminous bulb in which a luminous material is enclosed and a pair of electrodes are opposed in the luminous bulb; and a pair of sealing portions for sealing a pair of metal foils electrically connected to the pair of electrodes, respectively. At least one of the pair of sealing portions is provided with at least one constricted portion whose length in a thickness direction of the metal foil in the sealing portion is smaller than that of other portions in the sealing portion.

Abstract: A high-pressure discharge lamp is configured to regulate the relationship between the radius r (mm) of the tungsten rods forming the electrodes and the lamp current I (amperes) using the formula 1 1.

Abstract: A lamp unit includes a lamp provided with a mirror and a house for holding the lamp provided with a mirror. The lamp provided with a mirror includes a discharge lamp including a luminous bulb in which a luminous material is enclosed and a pair of electrodes are opposed to each other in the luminous bulb; and a pair of sealing portions for sealing a pair of metal foils electrically connected to the pair of electrodes, respectively; and a reflecting mirror for reflecting light emitted from the discharge lamp and having a front opening for emitting the reflected light. The lamp provided with a mirror is formed so as to have a non-airtight structure. The house includes a transmission window made of a material for transmitting light emitted from the front opening and positioned forward in the emission direction of the front opening of the reflecting mirror.

Abstract: A method for cleaning a translucent tube for a discharge lamp having a luminous bulb portion includes the steps of introducing a cleaning fluid from one end of the translucent tube; and allowing the cleaning fluid to flow while bringing the cleaning fluid in contact with at least an inner face of the luminous bulb portion of an inner face of the translucent tube, thereby removing impurities attached on the inner face of the luminous bulb portion.

Abstract: A short arc mercury lamp includes a luminous bulb enclosing at least mercury as a luminous material and a pair of electrodes opposed to each other; and a pair of sealing portions for sealing a pair of metal foils electrically connected to the pair of electrodes, respectively. The electrode central axis of one of the pair of electrodes is dislocated from the electrode central axis of the other electrode. The shortest distance d (cm) between the head of one of the electrodes and the head of the other electrode is larger than the value of (6M/13.6&pgr;)⅓ when the total mass of the enclosed mercury is M (g).