Abstract: In at least one embodiment of the disclosure, a driving device for a discharge lamp includes an alternating current supply section and a frequency modulation section. The alternating current supply section supplies two electrodes of the discharge lamp with an alternating current. The alternating current comprises a plurality of modulation periods. The frequency modulation section modulates a frequency of the alternating current so as to provide a plurality of retentive periods within each of the modulation periods. Each retentive period has a constant frequency that is different from a frequency of its temporally adjacent retentive periods. The frequency modulation section lengthens a length of at least one of the retentive periods in the modulation period in response to a predetermined condition occurring. The frequency of at least one of the retentive periods is equal to or higher than a predetermined reference frequency.

Abstract: To prevent biased consumption of electrodes in a discharge lamp and to prevent biased precipitation of the electrode material, a light source is provided. The light source device has a discharge lamp that emits light by discharge between a first electrode and a second electrode; and a driver that supplies alternating current to the first and the second electrodes so as to maintain the discharge, and changes duty ratio of the alternating current in accordance with predetermined pattern. The predetermined pattern includes a plurality of section periods for which the duty ratio maintains mutually different values for a predetermined period.

Abstract: A driving device for a discharge lamp includes: an alternating current supply section adapted to supply two electrodes of the discharge lamp with an alternating current; a frequency modulation section adapted to modulate a frequency of the alternating current, which the alternating current supply section supplies, in accordance with a predetermined condition of the discharge lamp within a range between a predetermined upper limit frequency and a predetermined lower limit frequency; and a modulation condition setting section adapted to set a modulation condition of the frequency by the frequency modulation section, wherein the modulation condition setting section sets the modulation condition so that the lower limit frequency when the discharge lamp is in a first state is higher than the lower limit frequency when the discharge lamp is in a second state in which a flicker is harder to occur than in the first state.

Abstract: In at least one embodiment of the disclosure, a driving device for a discharge lamp includes an alternating current supply section and a frequency modulation section. The alternating current supply section supplies two electrodes of the discharge lamp with an alternating current. The alternating current comprises a plurality of modulation periods. The frequency modulation section modulates a frequency of the alternating current so as to provide a plurality of retentive periods within each of the modulation periods. Each retentive period has a constant frequency that is different from a frequency of its temporally adjacent retentive periods. The frequency modulation section shortens a length of at least one of the retentive periods in the modulation period in response to a predetermined condition occurring. The frequency of at least one of the retentive periods is equal to or less than a predetermined reference frequency.

Abstract: A discharge lamp drive device for driving a discharge lamp including a first electrode and a second electrode, include: a power supply unit which supplies alternating power to the discharge lamp by inputting alternating current between the first electrode and the second electrode, wherein the power supply unit includes a power reduction control unit which reduces the alternating power from a first level to a second level lower than the first level, and a duty ratio control unit which steppedly varies duty ratio of the alternating current in a predetermined period at the time of reduction of the alternating power.

Abstract: To prevent biased consumption of electrodes in a discharge lamp and to prevent biased precipitation of the electrode material, a light source is provided. The light source device has a discharge lamp that emits light by discharge between a first electrode and a second electrode; and a driver that supplies alternating current to the first and the second electrodes so as to maintain the discharge, and changes duty ratio of the alternating current in accordance with predetermined pattern. The predetermined pattern includes a plurality of section periods for which the duty ratio maintains mutually different values for a predetermined period.

Abstract: To prevent biased consumption of electrodes in a discharge lamp and to prevent biased precipitation of the electrode material, a light source is provided. The light source device has a discharge lamp that emits light by discharge between a first electrode and a second electrode; and a driver that supplies alternating current to the first and the second electrodes so as to maintain the discharge, and changes duty ratio of the alternating current in accordance with predetermined pattern. The predetermined pattern includes a plurality of section periods for which the duty ratio maintains mutually different values for a predetermined period.

Abstract: A light source device includes: a discharge lamp provided with two electrodes; a discharge lamp lighting section adapted to light the discharge lamp by supplying the discharge lamp with electrical power while alternately switching a polarity of one of the electrodes of the discharge lamp with respect to the other of the electrodes; and a time-division color separation section adapted to receive light emitted from the discharge lamp in a lighted state and sequentially emit light beams with colors different from each other, wherein the discharge lamp lighting section switches the polarity in sync with a change in the color of the light beam emitted from the time-division color separation section, and provides, as retentive periods in which a duty ratio, which is a ratio of a positive polarity period with the polarity kept positive to a period of the polarity switching, is retained at a constant value over a predetermined period of time, a first retentive period and a second retentive period different in the dut

Abstract: To prevent biased consumption of electrodes in a discharge lamp and to prevent biased precipitation of the electrode material, a light source is provided. The light source device has a discharge lamp that emits light by discharge between a first electrode and a second electrode; and a driver that supplies alternating current to the first and the second electrodes so as to maintain the discharge, and changes duty ratio of the alternating current in accordance with predetermined pattern. The predetermined pattern includes a plurality of section periods for which the duty ratio maintains mutually different values for a predetermined period.

Abstract: A drive device that drives a discharge lamp including first and second electrodes includes a lighting circuit, a current control unit, a deformation detection unit, a current modulation unit, and a modulation enhancement unit. The lighting circuit supplies alternating current to the electrodes. The current control unit regulates the lighting circuit to control the alternating current. The deformation detection unit detects deformation of the surface shape of the electrodes. The current modulation unit modulates the controlled alternating current when the deformation is detected. The modulation enhancement unit increases a modulation ratio when the deformation is detected while modulating the alternating current.

Abstract: A discharge lamp lighting apparatus includes a power control circuit that outputs a DC current, an AC conversion circuit to which the DC current is inputted, the AC conversion circuit repeatedly reversing the polarity of the DC current between a first polarity and a second polarity at predetermined timings to produce and output a discharge lamp driving AC current, and a controller that controls the AC conversion circuit to perform AC conversion control in which the timings at which the polarity of the discharge lamp driving AC current is reversed are controlled and controls the power control circuit to perform section current control in which the magnitude of the DC current is controlled in each polarity reverse timing section.

Abstract: A light source device is provided. The light source device has: a discharge lamp that emits light by discharge in an interelectrode space between a first electrode and a second electrode; a main mirror arranged at the first electrode side that reflects light flux generated by the discharge in the interelectrode space so as to emit the light flux to an area to be illuminated; a sub-mirror arranged at the second electrode side facing opposite the main mirror that reflects the light flux from the interelectrode space toward the interelectrode space; and a driver that supplies alternating current to the first and the second electrodes, and changes duty ratio of the alternating current supplied to the first and the second electrodes in accordance with a predetermined pattern.

Abstract: To prevent biased consumption of electrodes in a discharge lamp and to prevent biased precipitation of the electrode material, a light source is provided. The light source device has a discharge lamp that emits light by discharge between a first electrode and a second electrode; and a driver that supplies alternating current to the first and the second electrodes so as to maintain the discharge, and changes duty ratio of the alternating current in accordance with predetermined pattern. The predetermined pattern includes a plurality of section periods for which the duty ratio maintains mutually different values for a predetermined period.

Abstract: In at least one embodiment of the disclosure, a driving device for a discharge lamp includes an alternating current supply section and a frequency switching section. The alternating current supply section supplies two electrodes of the discharge lamp with an alternating current. The alternating current includes a plurality of modulation periods with each modulation period including a highest frequency term and a lowest frequency term. The frequency switching section varies a frequency of the alternating current non-monotonically between the highest frequency term and the lowest frequency term of the modulation period in response to a predetermined condition being satisfied.

Abstract: A discharge lamp lighting device includes: a power control circuit that outputs a DC current; an AC converter circuit that takes the DC current as its input, inverts polarity of the DC current between first polarity and second polarity in predetermined timing, and thereby generates and outputs an AC current for discharge lamp driving; and a control unit that carries out AC conversion control processing to the AC converter circuit to control polarity inversion timing of the AC current for discharge lamp driving, and current control processing to the power control circuit to control a current value of the DC current. The control unit carries out repair control to change, in a first cyclical pattern, cumulative energy supplied to each electrode of a discharge lamp during one cycle of the AC current for discharge lamp driving, in predetermined timing.

Abstract: A light source includes an arc tube which emits light, a reflector which reflects the light emitted from the arc tube, and a holding unit which holds the reflector. The holding unit has an air supply port through which cooling air is introduced into the light source on the light emitting side of the arc tube, and a first rectifying portion which guides cooling air having been supplied from the air supply port and passed through the light emitting side of the arc tube toward an area above the arc tube.

Abstract: A discharge lamp drive device for driving a discharge lamp including a first electrode and a second electrode, include: a power supply unit which supplies alternating power to the discharge lamp by inputting alternating current between the first electrode and the second electrode, wherein the power supply unit includes a power reduction control unit which reduces the alternating power from a first level to a second level lower than the first level, and a duty ratio control unit which steppedly varies duty ratio of the alternating current in a predetermined period at the time of reduction of the alternating power.

Abstract: A projector includes an discharge lamp which has a first electrode and a second electrode and emits light by generating discharge between the first and second electrodes, and a driving system which supplies power by alternating polarities of the first electrode and the second electrode. The driving system is operable in a restoration mode. The driving system melts surface layers of a tip and a surrounding area of the tip extending from a main body of one of the first and second electrodes, and expands a new tip on a tip area of the main body of the one electrode in the restoration mode.

Abstract: A drive device that drives a discharge lamp including first and second electrodes includes a lighting circuit, a current control unit, a deformation detection unit, a current modulation unit, and a modulation enhancement unit. The lighting circuit supplies alternating current to the electrodes. The current control unit regulates the lighting circuit to control the alternating current. The deformation detection unit detects deformation of the surface shape of the electrodes. The current modulation unit modulates the controlled alternating current when the deformation is detected. The modulation enhancement unit increases a modulation ratio when the deformation is detected while modulating the alternating current.

Abstract: A light source device includes: a discharge lamp provided with two electrodes; a discharge lamp lighting section adapted to light the discharge lamp by supplying the discharge lamp with electrical power while alternately switching a polarity of one of the electrodes of the discharge lamp with respect to the other of the electrodes; and a time-division color separation section adapted to receive light emitted from the discharge lamp in a lighted state and sequentially emit light beams with colors different from each other, wherein the discharge lamp lighting section switches the polarity in sync with a change in the color of the light beam emitted from the time-division color separation section, and provides, as retentive periods in which a duty ratio, which is a ratio of a positive polarity period with the polarity kept positive to a period of the polarity switching, is retained at a constant value over a predetermined period of time, a first retentive period and a second retentive period different in the dut