Abstract: From a start of a lighting until a predetermined time period passes, a high-pressure discharge lamp is supplied with a constant current (Ib) until the lamp power reaches a predetermined wattage (Plow). When the lamp power reaches the wattage (Plow), current is supplied to maintain the lamp power at the wattage (Plow). After another predetermined time period passes, current is supplied to maintain the lamp power at a rated lamp wattage (Pr). While this lamp power is being maintained, the size of the lamp current is limited to a current limit (Ia). The current (Ib) and the wattage (Plow) satisfy a relationship Ia·0.7?Ib?Ia·0.9 and Pr·0.5 Plow?Pr·0.9 to accelerate an initial building of luminous flux while reducing drainage to the electrodes.

Abstract: The projector uses two lamps, which are high-pressure discharge lamps with the same rated power, as light sources. The projector includes: a first alternating-current generator configured to generate a lamp current to be supplied to one of the lamps, based on an input control signal; a second alternating-current generator configured to generate a lamp current to be supplied to the other lamp, based on an input control signal; and a controller configured to control the lamp currents to have a same period and to be out of phase, by inputting a control signal to each of the first and the second alternating-current generators.

Abstract: A calculation processing sub-unit controls a frequency control sub-unit and a DC-AC inverter circuit to repeat a first period and a second period. The first period continues for at least two cycles, each cycle including a first sub-period during which the current is maintained in one polarity and a second sub-period during which the current is maintained in an opposite polarity. The second sub-period is shorter than and subsequent to the first sub-period. The second period, during which the current is maintained in a constant polarity, is as long as or longer than the first sub-period. The calculation processing sub-unit controls a PWM control sub-unit and a voltage step-down circuit to maintain an absolute value of the current at a first current value during at least part of the first period, and at a second current value, greater than the first current value, during the second period.

Abstract: A calculation processing sub-unit 11 controls a frequency control sub-unit 13 and a DC-AC inverter circuit 6 to repeat an A-period and a B-period. The A-period continues for at least two cycles, each cycle including a period a1 during which the current is maintained in one polarity and a period a2 during which the current is maintained in an opposite polarity. The period a2 is shorter than and subsequent to the period a1. The B-period, during which the current is maintained in a constant polarity, is as long as or longer than the period a1. The calculation processing sub-unit 11 controls a PWM control sub-unit 12 and a voltage step-down circuit 5 to maintain an absolute value of the current at a first current value during at least part of the A-period, and at a second current value, greater than the first current value, during the B-period.

Abstract: The present invention provides a high pressure discharge lamp with a start-up assist member, a lamp unit, and a lamp system that reduce breakdown voltage and provide high design flexibility by reducing restriction on a position of an adjacent conductor. In a high pressure discharge lamp (10) of a lamp unit (1), a dielectric member (20) is on the outer surface of a first sealing part (101a). The dielectric member (20) made of a titanium compound has relative permittivity higher than that of fused quartz. An upstream end of a metal wire (21) is connected to an external lead wire (102b) projecting from a second sealing part (101b). A downstream end (21A) is in contact with the dielectric member (20). Upon lighting of the lamp, a corona discharge occurs at the point where the end (21a) is in contact with the dielectric member (20) so that breakdown voltage is reduced.

Abstract: A projection-type image display apparatus includes a high pressure discharge lamp, which utilizes the halogen cycle, and a lamp lighting apparatus that controls lighting of the high pressure discharge lamp. The lamp lighting apparatus performs lamp refresh processing to improve a lamp property. The lamp refresh processing involves performing low power lighting of the high pressure discharge lamp by changing the lighting power of the high pressure discharge lamp to a value that is lower than the rated power, and thereafter performing high power lighting of the high pressure discharge lamp by changing the lighting power to a value that is higher than the lighting power during the low power lighting.

Abstract: A high-pressure discharge lamp lighting device that suppresses deterioration and the expansion of inter-electrode distance in a pair of electrodes within a high-pressure discharge lamp, more effectively than conventional technology. The frequency of the AC current supplied to a high-pressure discharge lamp alternates between a first frequency and a second, higher frequency, while the magnitude of the AC current alternates between a first value and a second, higher value. The suppressing effect is realized by repeatedly alternating the frequency and repeatedly alternating between a first period at the first frequency and a second period at the second frequency, with the second, higher-magnitude current being used in the latter and the first current being used in the former.

Abstract: Constant current control is performed after the completion of starting operation of a high-pressure mercury-vapor lamp 4 and then lighting is shifted to constant power lighting. Except during a modulation forbidden period as a certain period from the completion of the starting operation, the frequency of an alternating current is subjected to frequency modulation control for being modulated to at least a first frequency and a second frequency having higher audibility than the first frequency.

Abstract: A first waveform (a rectangular waveform, for example) is applied as the waveform of the alternating current supplied to a high-pressure discharge lamp for a predetermined time from the beginning of lighting of the lamp and a second waveform (a staircase waveform, for example) is applied as the waveform of the alternating current after the elapse of a predetermined time (100 [s], for example). The alternating current with the first waveform has a lower absolute instantaneous value in a final section of each half-cycle period thereof than in the other sections and the alternating current with the second waveform has a higher absolute instantaneous value in a final section of each half-cycle period thereof than in the other sections.

Abstract: The frequency of the alternating current to be supplied to the high-pressure discharge lamp is switched among a first frequency, a second frequency greater than the first frequency, and a third frequency smaller than or equal to the first frequency. In the switching, a period A, in which the alternating current of the third frequency is supplied, occurs at the beginning of each of the predetermined time intervals. A remainder of each of the predetermined time intervals includes a period B, in which the alternating current of the first frequency is supplied, and a period C, in which the alternating current of the second frequency is supplied, the periods B and C being alternately repeated, so as to control the period A to be longer than the period B and to have a length corresponding to a predetermined number of cycles, ranging from 5.5 to 50 cycles inclusive.

Abstract: The present invention provides a high pressure discharge lamp with a start-up assist member, a lamp unit, and a lamp system that reduce breakdown voltage and provide high design flexibility by reducing restriction on a position of an adjacent conductor. In a high pressure discharge lamp 10 of a lamp unit 1, a dielectric member 20 is on the outer surface of a first sealing part 101A. The dielectric member 20 made of a titanium compound has relative permittivity higher than that of fused quartz. An upstream end of a metal wire 21 is connected to an external lead wire 102B projecting from a second sealing part 101B. A downstream end 21a is in contact with the dielectric member 20. Upon lighting of the lamp, a corona discharge occurs at the point where the end 21a is in contact with the dielectric member 20 so that breakdown voltage is reduced.

Abstract: A high-pressure discharge lamp system has a high-pressure mercury lamp 4 and a lighting circuit 3 that operates the lamp 4. The lamp 4 includes an envelope having a light emitting part 6 having a first and a second electrode 10, 11 arranged therein and a first and a second sealing part 7, 8 oppositely extending from the light emitting part 6, and a conductor 20 electrically connected to the second electrode 11. Particularly a portion of the conductor 20 is at least in contact with or in closest proximity to the outer surface of the first sealing part 7 substantially at a single point in an area corresponding to a first metal foil 16 connected to the first electrode 10. The circuit 3 activates the lamp 4 by placing high-frequency voltage at a predetermined frequency within a range of 10 [kHz]-10 [MHz], inclusive, between the electrodes 10, 11.

Abstract: A high-pressure discharge lamp lighting device that suppresses deterioration and the expansion of inter-electrode distance in a pair of electrodes within a high-pressure discharge lamp, more effectively than conventional technology. The frequency of the AC current supplied to a high-pressure discharge lamp alternates between a first frequency and a second, higher frequency, while the magnitude of the AC current alternates between a first value and a second, higher value. The suppressing effect is realized by repeatedly alternating the frequency and repeatedly alternating between a first period at the first frequency and a second period at the second frequency, with the second, higher-magnitude current being used in the latter and the first current being used in the former.

Abstract: From the start lighting until a predetermined time passes, a high-pressure discharge lamp 4 is supplied a constant current Ib until the lamp power reaches a wattage Plow. When the lamp power reaches the wattage Plow, current is supplied to maintain the lamp power at the wattage Plow. After the predetermined time passes, current is supplied to maintain the lamp power at a rated lamp wattage Pr. While the lamp power is being maintained, the size of the lamp current is limited to a current limit Ia. The current Ib and the wattage Plow, satisfy the relationships Ia·0.7?Ib?Ia·0.9 and Pr·0.5?Plow?Pr·0.9.

Abstract: In a high-pressure discharge lamp that includes a bulb formed from a light emitting part having a discharge space therein and a pair of sealing parts connected to the light emitting part, and an electrode pair disposed within the discharge space, a section of a proximity conductor is wound substantially spirally around one of the sealing parts within a predetermined range from the light emitting part, while the remaining section of the proximity conductor crosses over the light emitting part and is electrically connected to the electrode nearer the other sealing part. By initiating a discharge after applying a high-frequency voltage of 1 kHz to 1 MHz to a high-pressure mercury lamp having this structure, the breakdown voltage can be suppressed to at least 8 kV.

Abstract: The projector uses two lamps, which are high-pressure discharge lamps with the same rated power, as light sources. The projector includes: a first alternating-current generator configured to generate a lamp current to be supplied to one of the lamps, based on an input control signal; a second alternating-current generator configured to generate a lamp current to be supplied to the other lamp, based on an input control signal; and a controller configured to control the lamp currents to have a same period and to be out of phase, by inputting a control signal to each of the first and the second alternating-current generators.

Abstract: A manufacturing method of a high-pressure mercury lamp includes an electric field application step in which an electric field is applied to at least a light emission part (4) with the high-pressure mercury lamp being kept at a high temperature. This can reduce impurities such as hydrogen and alkali metals in a discharge space (8) and glass forming the light emission part (4). As a consequence, blackening and devitrification of the high-pressure mercury lamp while the lamp is lit can be reduced.

Abstract: In a high-pressure discharge lamp that includes a bulb formed from a light emitting part having a discharge space therein and a pair of sealing parts connected to the light emitting part, and an electrode pair disposed within the discharge space, a section of a proximity conductor is wound substantially spirally around one of the sealing parts within a predetermined range from the light emitting part, while the remaining section of the proximity conductor crosses over the light emitting part and is electrically connected to the electrode nearer the other sealing part. By initiating a discharge after applying a high-frequency voltage of 1 kHz to 1 MHz to a high-pressure mercury lamp having this structure, the breakdown voltage can be suppressed to at least 8 kV.

Abstract: The high-pressure discharge lamp lighting device of the invention includes a lighting circuit for supplying an alternating current to a high-pressure discharge lamp to cause lighting, the high-pressure discharge lamp having an arc tube in which a halogen material is enclosed and a pair of electrodes is disposed, and each electrode having a protuberance at a tip thereof. A frequency of the alternating current varies without dependency on operating data that varies as a lighting time of the high-pressure discharge lamp elapses.

Abstract: The high-pressure discharge lamp lighting device and a high-pressure discharge lamp apparatus using this of the present invention are able to suppress the excessive drop in the lamp voltage in a high-pressure discharge lamp. The frequency of the alternating current to be supplied to the high-pressure discharge lamp 4 is switched among a first frequency, a second frequency greater than the first frequency, and a third frequency smaller than or equal to the first frequency. In the switching, a time period A, in which the alternating current of the third frequency is supplied, occurs at beginning of each of predetermined time intervals.