Abstract: A high watt type ceramic metal halide lamp illumination device is provided. The device comprises: ballast receiving a primary input voltage and outputting a secondary voltage, and a lamp having a plurality of arc tubes electrically connected in series inside an outer bulb. The lamp is lighted by receiving the secondary voltage output from the ballast. The secondary voltage output from the ballast has a waveform that at least satisfies a maximum-value to effective-value ratio (Vmax/Veff) of greater than 20.5. When using two 360 W arc tubes of a popular type by electrically connecting the two in series instead of a 700 W arc tube of a high-watt type, for example, it is preferable to use a triangular waveform AC voltage that satisfies 260?Veff(triangular waveform) when expressed by the effective-value, and 500 V?Vmax(triangular waveform) when expressed by the maximum-value.

Abstract: Aspects of the disclosure include a ceramic metal halide lamp in which two arc tubes are arranged electrically in series inside the same outer globe. By arranging the two arc tubes in such a way that light-emitting parts thereof do not overlap, decline in lifespan due to the heat of one arc tube causing the temperature of the other arc tube to increase and lighting failure due to an increase in lamp voltage do not occur. And by setting the distance from an electrode tip at a base side of the first arc tube to an electrode tip at a lamp-top side of the second arc tube to be equal to or less than 3.5 times the average inter-electrode distance of both arc tubes, a preferable distribution of light is implemented.

Abstract: A starting light source for radiating the UV-light to a discharge chamber upon starting lighting of a high pressure discharge lamp includes a discharge tube for generating the UV-light by a starting voltage applied upon starting lighting the lamp, the discharge tube includes an internal electrode extended from a pinch seal portion formed at one end to a light-emitting portion thereof and an external electrode disposed close to or in contact with both of the light-emitting portion and the pinch seal portion, at least a portion of the external electrode disposed for the light-emitting portion includes a holder formed by bending fabrication of a metal sheet into such a shape of gripping and holding the discharge tube, and a terminal is formed to the holder for fixing and electrically connecting the external electrode to a conductor part having a polarity opposite to that of the internal electrode.

Abstract: The high pressure discharge lamp ballast drives a high pressure discharge lamp with a synthesized-waveform alternating current made of multiple frequency components, the high pressure discharge lamp having a pair of electrodes disposed to face each other. The ballast controls a ratio of the multiple frequency components per unit time; applies a synthesized-waveform current in accordance with the ratio to the high pressure discharge lamp; and detects a lamp parameter of the high pressure discharge lamp. The control circuit is configured to shift the ratio to a first ratio when the lamp parameter is in a first state, and shifts the ratio to a second ratio when the lamp parameter is in a second state. The control circuit changes the ratio stepwise when the ratio is shifted from the first ratio to the second ratio, or when the ratio is shifted from the second ratio to the first ratio.

Abstract: A high pressure discharge lamp ballast performs driving with a synthesized current waveform comprising a combination of first and second sets of current waveforms. The ballast controls content rates of each of the sets per unit time; detects a rotation synchronization signal for a color wheel; applies a synthesized current waveform in accordance with the synchronization signal and the content rates to a high pressure discharge lamp; and detects a lamp voltage. A period of each of the first and second sets equals to one rotation of the color wheel. The number of inversions of the second set is larger than that of the first set. The content rate of the second set is set to RL% when the lamp voltage exceeds a value V, and the content rate of the second set is set to RH% when lamp voltage falls below a value V?.

Abstract: A start assisting light source is configured such that it can be mounted simply and reliably at a position capable of efficiently radiating UV-light for enhancing the starting performance of a high pressure discharge lamp to discharge chamber without being heated to a high temperature during lighting of the lamp and also adopted to a simple constitution of not increasing the manufacturing cost. A start assisting light source includes an airtight vessel filled with a rare gas and a pipe member that penetrates through the vessel is mounted to an electrode lead which protrudes from the end face of an electrode seal portion secured to a bottom hole of the concave reflector by inserting the electrode lead through the pipe member.

Abstract: Provided is a manufacturing method to prevent devitrification of a bulb in a high pressure discharge lamp used for a projector. The method is for manufacturing a high pressure discharge lamp which uses, as a light source, a bulb made of fused quartz and including a tungsten electrode, and which is horizontally installed when the lamp is driven for actual use. The method includes the step of initially driving the bulb with an optical axis thereof being set horizontally before the high pressure discharge lamp is shipped. In the initial driving step, the rotation angle around the optical axis of the bulb is offset by 45° or more and 135° or less relative to the rotation angle around the optical axis of the bulb when the lamp is driven for actual use.

Abstract: A necessary and sufficient amount of a UV-light is radiated to a high pressure discharge lamp for enabling reliable improvement in the starting performance by a starting light source of a simple configuration not increasing the manufacturing cost.

Abstract: A start assisting light source is configured such that it can be mounted simply and reliably at a position capable of efficiently radiating UV-light for enhancing the starting performance of a high pressure discharge lamp to discharge chamber without being heated to a high temperature during lighting of the lamp and also adopted to a simple constitution of not increasing the manufacturing cost. A start assisting light source includes an airtight vessel filled with a rare gas and a pipe member that penetrates through the vessel is mounted to an electrode lead which protrudes from the end face of an electrode seal portion secured to a bottom hole of the concave reflector by inserting the electrode lead through the pipe member.

Abstract: Provided is a manufacturing method to prevent devitrification of a bulb in a high pressure discharge lamp used for a projector. The method is for manufacturing a high pressure discharge lamp which uses, as a light source, a bulb made of fused quartz and including a tungsten electrode, and which is horizontally installed when the lamp is driven for actual use. The method includes the step of initially driving the bulb with an optical axis thereof being set horizontally before the high pressure discharge lamp is shipped. In the initial driving step, the rotation angle around the optical axis of the bulb is offset by 45° or more and 135° or less relative to the rotation angle around the optical axis of the bulb when the lamp is driven for actual use.

Abstract: In a frequency control for a high pressure discharge lamp ballast, short-term increase and decrease of a lamp voltage are suppressed. The high pressure discharge lamp ballast drives a high pressure discharge lamp with a synthesized-waveform alternating current made of multiple frequency components, the high pressure discharge lamp having a pair of electrodes disposed to face each other. The ballast includes: a control means for controlling a component contained ratio of the multiple frequency components per unit time; an output means for applying a synthesized-waveform current in accordance with the component contained ratio to the high pressure discharge lamp; and detection means for detecting a lamp parameter of the high pressure discharge lamp.

Abstract: Even when usable driving frequencies are limited, a lamp voltage is appropriately controlled. A high pressure discharge lamp ballast performs driving with a synthesized current waveform comprising a combination of first and second sets of current waveforms. The ballast includes: a control means for controlling content rates of each of the sets per unit time; a detection means for detecting a rotation synchronization signal for a color wheel; an output means for applying a synthesized current waveform in accordance with the synchronization signal and the content rates to a high pressure discharge lamp; and a detection means for detecting a lamp voltage. The sets are each in a waveform inverted so as to correspond to at least one of a rotational speed and segment positions of color wheel. A period of each of the first and second sets has a length equivalent to one rotation of the color wheel. The number of inversions of the second set is larger than the number of inversions of the first set.

Abstract: In a case of manufacturing a double ended discharge lamp, it is intended to decrease the manufacturing cost while maintaining identical lamp characteristic and lamp lifetime with those in a case of forming a quartz bulb with quartz at a high purity. In a quartz bulb (1) in which a pair of straight tube portions (2A, 2B) each having a sealing tube (4A, 4B) for sealing an electrode mount (M) and a supply/exhaust tube (5A, 5B) that is cut and removed after sealing in communication to each other are formed on both ends of a chamber (3) as a light emitting portion, end portions (1A, 1B) of the quartz tube including the entire portion or a portion of the supply/exhaust tubes (5A, 5B) are formed in contiguous with the central portion (10) of the quartz tube including all portions forming the inner surface (3a) of the chamber, and one or both of the end portions (1A, 1B) of the quartz tube is formed of quartz at a purity lower than that of the central portion (10) of the quartz tube.