Realizing a constant-current control even in a stable state of a lamp without increasing a rated output of a power supply. In a stable state of the lamp in which a change value of a lamp voltage after a discharge lamp is turned on becomes less than a certain value, when the lamp voltage rises, a discharge lamp lighting control apparatus changes a current command value to perform a constant-current control. This change is a change from a first current command value at the time when the discharge lamp is turned on to a second current command value that is smaller than the former by a predetermined value. Using this second current command value, the constant-current control is performed. Even after that, the second current command value is changed to a smaller value every time the lamp voltage rises, and the constant-current control is performed using the second current command value.

Provided is a new light source device using an excimer lamp, particularly, a light source device for sterilization and deodorization. The light source device includes an excimer lamp and a flyback-type lighting device that supplies power to the excimer lamp. The lighting device includes a transformer, a switching element, and a control circuit that supplies a drive signal to the switching element. The control circuit controls the switching element on and off so that the switching frequency (FS) for the switching element at the time of starting to light is lower than the switching frequency (FO) at the time of steady-state lighting, and the ON-duty (TS) for the switching element at the time of starting to light is lower than the ON-duty (TO) at the time of steady-state lighting.

Provided is a new light source device using an excimer lamp, particularly, a light source device for sterilization and deodorization. The light source device includes an excimer lamp and a flyback-type lighting device that supplies power to the excimer lamp. The lighting device includes a transformer, a switching element, and a control circuit that supplies a drive signal to the switching element. The control circuit controls the switching element on and off so that the switching frequency (FS) for the switching element at the time of starting to light is lower than the switching frequency (FO) at the time of steady-state lighting, and the ON-duty (TS) for the switching element at the time of starting to light is lower than the ON-duty (TO) at the time of steady-state lighting.

Realizing a constant-current control even in a stable state of a lamp without increasing a rated output of a power supply. In a stable state of the lamp in which a change value of a lamp voltage after a discharge lamp is turned on becomes less than a certain value, when the lamp voltage rises, a discharge lamp lighting control apparatus changes a current command value to perform a constant-current control. This change is a change from a first current command value at the time when the discharge lamp is turned on to a second current command value that is smaller than the former by a predetermined value. Using this second current command value, the constant-current control is performed. Even after that, the second current command value is changed to a smaller value every time the lamp voltage rises, and the constant-current control is performed using the second current command value.

The lighting circuit for lighting a dielectric barrier discharge lamp includes a direct-current power source, a transformer having a primary winding connected to a positive electrode-side terminal of the direct-current power source and a secondary winding connected to the dielectric barrier discharge lamp, a closed circuit in which the direct-current power source, the primary winding, and a switching element including a parasitic diode are serially connected, and a controller to perform ON/OFF control of the switching element. The controller executes a first step to shift the switching element from an ON state to an OFF state and a second step to shift the switching element from the OFF state to the ON state after a lapse of a predetermined OFF holding time from when a regenerative current flowing through the primary winding reaches a zero value after the first step.

In a caser where a first current is supplied to a first heater, a controller gradually increases the first current in a first period, supplies the first current based on a first duty cycle in a second period, and gradually reduces the first current to stop supplying the first current in a third period. In a case where a second current is supplied to a second heater, the controller gradually increases the second current in a fourth period, supply the second current based on a second duty cycle in a fifth period, and gradually reduces the second current to stop supplying the second current in a sixth period. The controller controls the supply of the second current such that part of the fourth period overlaps with the third period.

A discharge lamp driving device includes: a discharge lamp driving unit which supplies drive power to a discharge lamp; and a control unit which controls the discharge lamp driving unit according to a waveform of the drive power. The waveform has n launching periods and a low-power mode lighting period. The n launching periods include a first launching period in which the drive power increases toward refresh power that is equal to or above drive power in a low-power mode and equal to or below rated power, and (n1) launching periods in which the drive power is maintained at the refresh power. The control unit, in an x-th launching period, supplies the discharge lamp with a drive current having a drive frequency equal to or below a drive frequency of a drive current supplied to the discharge lamp in an (x1)th launching period.

A dynamically optimized ballast includes a ballast and a circuit board as main components combined together. Said circuit board is provided with a microcontroller, a timer and a current-switching device; wherein said microcontroller is provided with a timed step-up module which can start the timer and maintain a low current output to HID lamp at the time the circuit board is powered, and the timer will transmit a signal to the microcontroller to start the current-switching device and automatically switch to a high current output to HID lamp when a preset time of the timer has been reached. So that this invention can protect HID lamp and extend the service life of HID lamp, even the HID lamp pulsing for a long time, the power source repeated power supply and power out will not cause great damage to HID lamp and it will not be out of function. Besides, this invention enables user to reduce the brightness of HID lamp to reduce the loss of electric power and the deterioration of HID lamp.

An apparatus for producing light includes a chamber and an ignition source that ionizes a gas within the chamber. The apparatus also includes at least one laser that provides energy to the ionized gas within the chamber to produce a high brightness light. The laser can provide a substantially continuous amount of energy to the ionized gas to generate a substantially continuous high brightness light.

A discharge lamp driving device includes: a discharge lamp driving unit which supplies drive power to a discharge lamp; and a control unit which controls the discharge lamp driving unit according to a waveform of the drive power. The waveform has n launching periods and a low-power mode lighting period. The n launching periods include a first launching period in which the drive power increases toward refresh power that is equal to or above drive power in a low-power mode and equal to or below rated power, and (n1) launching periods in which the drive power is maintained at the refresh power. The control unit, in an x-th launching period, supplies the discharge lamp with a drive current having a drive frequency equal to or below a drive frequency of a drive current supplied to the discharge lamp in an (x1)th launching period.