Patent ID: 8348437

Claim:
A discharge lamp lighting device comprising: an electric power converting circuit configured to supply an alternating-current power to a discharge lamp by switching a switching element on and off; a control circuit configured to control an output from the electric power converting circuit by controlling on and off of the switching element of the electric power converting circuit, and to shift the output control of the electric power converting circuit from a current limit region to a constant electric power control region after the discharge lamp starts to be lighted, a lamp current being controlled not to exceed a current limit in the current limit region, and a lamp electric power being controlled to remain constant in the constant electric power region; and a storage that stores a history of the output from the electric power converting circuit in a previous stable lighting mode of the discharge lamp, wherein, on the basis of the history stored in the storage, the control circuit suppresses a rise of a lamp voltage by changing the output from the electric power converting circuit in a predetermined time period, the predetermined time period being within a time period after the discharge lamp starts to be lighted until the discharge lamp enters a stable lighting mode, and shorter than the time period, wherein the control circuit temporarily changes a setting value of the output from the electric power converting circuit in the predetermined time period to a value that is determined according to the stored history of the output from the electric power converting circuit in the previous stable lighting mode, wherein on the basis of the history stored in the storage, the control circuit sets an operating frequency of the discharge lamp in the predetermined time period to be higher than an operating frequency in the previous stable lighting mode, wherein the control circuit generally maintains a constant operating frequency calculated on the basis of the history stored in the storage, in the predetermined time period, and wherein the predetermined time period is a time period in which the lamp voltage is between a first voltage and a second voltage, while the lamp voltage is rising after the discharge lamp starts to be lighted, the second voltage being greater than the first voltage, wherein the second voltage is set at a lamp voltage with which the output control of the electric power converting circuit is shifted to the constant electric power control region.