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: In at least one embodiment of the disclosure, a method for driving a discharge lamp includes changing a duty ratio of an AC current to be supplied between a first electrode and a second electrode of the discharge lamp in accordance with a predetermined pattern, and setting a current value when the first electrode operates as an anode during one cycle so as to be smaller than a current value when the second electrode operates as an anode during one cycle.

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 includes: an emitting portion in which a pair of electrodes are disposed, an electric discharge being generated between the pair of electrodes so as to emit light; at least either one electrode of the pair of the electrodes including: a small-diameter portion; and a large-diameter portion provided on an end of the small-diameter portion closer to the other electrode, the large-diameter portion having a larger diameter than the small-diameter portion; and the large-diameter portion including a projecting part, the projecting part projecting outward from the large-diameter portion.

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: A light emitting module device includes: a power line through which power is supplied to light emitting modules; and a signal generation circuit which generates a control signal. The power line is shared by a plurality of the light emitting modules, and has switches and switches which turn on or off current conduction to the light emitting modules, through open/close operations. The signal generation circuit individually controls the switches and the switches. The open/close operations include a light-emission period in which the light emitting module emits light; and an extinction period in which the light emitting module is extinguished, and if there is a control signal to be transmitted to the light emitting module, the control signal is superimposed onto supply power. Since a control signal is superimposed onto supply power to each light emitting module, the light emitting modules can be individually controlled.

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 method for driving a discharge lamp that supplies an AC current to a discharge lamp having a first electrode and a second electrode so as to produce discharge and to cause the discharge lamp to emit light includes the steps of, during a steady operation in which the AC current is supplied to the first electrode and the second electrode, when power of the same amount is fed to the first and second electrodes, and a tip portion of the first electrode becomes higher than a tip portion of the second electrode in temperature, changing the duty ratio of the AC current to be supplied between the first electrode and the second electrode in accordance with a predetermined pattern, and setting a current value when the first electrode operates as an anode during one cycle so as to be smaller than a current value when the second electrode operates as an anode during one cycle.

Abstract: A driving device for a discharge lamp includes: a discharge-lamp lighting unit that supplies an alternating current to the discharge lamp to thereby supply electric power to between two electrodes of the discharge lamp; an inter-electrode-voltage detecting unit that detects an inter-electrode voltage applied when predetermined electric power is supplied to between the two electrodes; and a power-supply-condition switching unit that switches, on the basis of the detected inter-electrode voltage, the power supply by the discharge-lamp lighting unit with a predetermined hysteresis given to the switching of the power supply conditions, wherein the power supply conditions are switched by changing at least one of a frequency of the alternating current, a duty ratio of the alternating current, a modulation pattern of the frequency, and a modulation pattern of the duty ratio.

Abstract: A discharge lamp lighting device includes: a power control circuit outputting DC current; an AC conversion circuit being supplied with the DC current and generating and outputting discharge-lamp driving AC current by inverting the polarity of the DC current at a predetermined time; and a control unit performing a duty ratio control process of controlling a duty ratio on the basis of a polarity inversion time of the discharge-lamp driving AC current on the AC conversion circuit and performing an interval current control process of controlling a current value of the DC current every polarity inversion time interval on the power control circuit. Here, the control unit performs the interval current control process so as to control a difference between an average value and a maximum value of the DC current of each polarity inversion time interval on the basis of a difference between the duty ratio and a predetermined reference duty ratio.

Abstract: A driving device of an electric discharge lamp includes: a discharge lamp lighting unit which supplies power to the electric discharge lamp while alternately switching polarity of voltage applied between two electrodes of the electric discharge lamp to lighting the electric discharge lamp; and an anode duty ratio modulating unit which sets at least a first retention period and a second retention period having an anode duty ratio different from that of the first retention period and provided after the first retention period to modulate the anode duty ratios, assuming that each of the retention periods is a period for retaining an anode duty ratio as ratio of an anode period in which one of the electrodes operates as anode at a constant value in one cycle of the polarity switching, wherein the anode duty ratio modulating unit has a first modulation mode for operating the electric discharge lamp in steady condition and a second modulation mode for providing larger change of the anode duty ratio between the first

Abstract: In at least one embodiment of the disclosure a discharge lamp lighting device includes a controller configured to control an AC conversion circuit to perform AC conversion control for controlling the timings at which a polarity of the discharge lamp driving AC current is reversed. The controller is configured to control the power control circuit to perform current control for controlling a current value of the DC current. The controller changes the cumulative energy supplied to each electrode of a discharge lamp in one cycle of the AC current for the discharge lamp driving in accordance with a cyclical pattern. The cyclical pattern includes a plurality of segmented periods during each of which the cumulative energy is maintained at a same level for a plurality of cycles of the AC current for the discharge lamp driving, and a level of the cumulative energy in at least two of the segmented periods differ from each other.

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 driving method for a discharge lamp that lights by performing discharge between two electrodes while alternately switching a polarity of a voltage applied between the two electrodes includes: modulating an anode duty ratio, which is a ratio of an anode time for which one of the electrodes operates as an anode in one period of the polarity switching, by setting first and second periods with different anode duty ratios; and setting a first polarity switching period in the first period to be shorter than a second polarity switching period in the second period.

Abstract: A method for driving a discharge lamp that supplies an AC current to a discharge lamp having a first electrode and a second electrode so as to produce discharge and to cause the discharge lamp to emit light includes, during a steady operation in which the AC current is supplied to the discharge lamp, changing a difference between the absolute values of average current values for two polarities during one cycle of the AC current in accordance with a predetermined pattern.

Abstract: A driving method for a discharge lamp that lights by performing discharge between two electrodes while alternately switching a polarity of a voltage applied between the two electrodes includes: modulating an anode duty ratio, which is a ratio of an anode time for which one of the electrodes operates as an anode in one period of the polarity switching, within a predetermined range; and changing the predetermined range to make a maximum value of the modulated anode duty ratio higher than a maximum value of an initial anode duty ratio of the discharge lamp when a predetermined condition is satisfied.

Abstract: A method for driving a discharge lamp that lights by performing discharge between two electrodes while alternately switching a polarity of a voltage applied between the two electrodes includes: modulating an anode duty ratio, which is a ratio of an anode time for which one of the electrodes operates as an anode in one period of the polarity switching, by setting first and second periods with different anode duty ratios; and setting the first period, in which the anode duty ratio is higher than that in the second period, longer than the second period in one modulation period, which includes the first and second periods and for which the modulation is performed, when a predetermined condition is satisfied.

Abstract: A method for driving a discharge lamp that supplies an AC current to a discharge lamp having a first electrode and a second electrode so as to produce discharge and to cause the discharge lamp to emit light includes, during a steady operation in which the AC current is supplied to the discharge lamp, changing a difference between the absolute values of average current values for two polarities during one cycle of the AC current in accordance with a predetermined pattern.