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: 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: 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: 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: 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.

Abstract: After startup, a lighting method for a high-pressure discharge lamp is to light the lamp at a rated frequency without switching the frequency for 120 seconds (S12, S13), and thereafter to switch from the rated frequency to a more audible frequency in accordance with a change in voltage value (S21 to S23).

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 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: 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: 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 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: 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: The present invention provides a high-pressure discharge lamp having a long life. A high-pressure discharge lamp (100) comprises a light emitting part (4); first and second sealing parts (6, 8); first and second electrodes (10, 11); a first conductive lead (21) wound around the first sealing part; a first lead wire (22) electrically connecting the first conductive lead to the first electrode; a second conductive lead (25) wound around the second sealing part; and a second lead wire (26) connecting the second conductive lead to the first electrode. The second lead wire detours the light emitting part to avoid being affected by heat. After the lamp is turned off, the temperature of base parts of the electrodes immediately falls, and much mercury can be collected in the vicinities of the base parts.