Eye Lighting Systems Corporation

Kensuke Kaneko

Yoshihisa Umezawa

Tomokazu Osato

A lighting device has a direct-current power generation circuit, a rectangular-wave generation circuit, a pulse generating circuit, lamp-voltage detection means, and pulse-generation command means. The direct-current power generation circuit generates direct-current power from external power. The rectangular-wave generation circuit converts the direct-current power to rectangular-wave alternating-current power. The pulse generating circuit superposes high-voltage pulses on the rectangular-wave power output from the rectangular-wave generation circuit and starts a discharge lamp. The lamp-voltage detection means detects, in digital form, a lamp voltage supplied to the discharge lamp. The pulse-generation command means issues a pulse generation command to the pulse generating circuit when the value detected by the lamp-voltage detection means reaches a predetermined no-load-voltage determination level.

Discharge-lamp lighting device

A lighting device has a power-factor correction circuit, a step-down chopper circuit, a full-bridge circuit, control ICs for these circuits and a driving-voltage supply circuit. The supply circuitsupplies a driving voltage to the control ICs. The control IC outputs the on/off driving voltage to a switching element of the corresponding circuitto. The lighting device also has a detectorand judgment equipment. The detectordetects the driving voltage supplied from the supply circuit. The judgment equipmentinstructs the control ICs to start outputting the on/off driving voltages in the order from the control IC close to the power sourceto the control IC close to the discharge lampwhen the driving voltage detected by the detectorreaches a predetermined value during the time when the driving voltage supplied from the supply circuitrises.

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Konosu, Japan

Kensuke Kaneko