| Patent application number | Description | Published |
| 20100148686 | HIGH PRESSURE DISCHARGE LAMP LIGHTING APPARATUS - A discharge lamp lighting apparatus includes a discharge container, a pair of electrodes and a power supply apparatus. An alternating current of a frequency, which is lower than stationary frequency, is inserted periodically into the alternating current of stationary frequency. When a lighting current value of the discharge lamp is smaller than a predetermined lower limit, the frequency is set as predetermined minimum frequency. When the lighting current value of a discharge lamp is larger than a predetermined maximum value, the frequency is set as predetermined maximum frequency. When a lighting current value of the discharge lamp is between the lower limit and the maximum value, the frequency is set as a selected frequency corresponding to the lighting current value. The selected frequency increases according to an increase of frequency change as a lighting current value increases. | 06-17-2010 |
| 20110025203 | High pressure discharge lamp - The present invention relates to a high pressure discharge lamp that includes a pair of electrodes, which face each other in an electric discharge space. Further, an electrode axis of one of the electrodes is joined to a metallic foil in a sealing portion, and two or more grooves are formed in an axis direction on a portion corresponding to the sealing portion on the electrode axis. Furthermore, a remaining portion that lacks grooves is left on the electrode axis in a metallic foil side thereof, and the metallic foil side ends of the grooves are not aligned with each other in the axis direction thereof. | 02-03-2011 |
| 20110043771 | High pressure discharge lamp lighting apparatus and projector - A high pressure discharge lamp lighting apparatus that comprises a power supply apparatus that supplies a rectangle wave alternating current to the high pressure discharge lamp for lighting, such that when the lamp is operated by electric power of 0.5×P (W) or less, when maximum operation power P (W) in a steady lighting state except an initial lighting period that is immediately after starting, where a first polarity driving period of a rectangle wave alternating current is Ta (seconds), and where a second polarity driving period is Tb (seconds) an operation is performed so that the second polarity driving period Tb is 5 ms or less (Tb≦5 ms) and a ratio Tb/Ta of these two driving periods is 0.1 or less (Tb/Ta≦0.1). | 02-24-2011 |
| 20110063584 | High pressure discharge lamp lighting apparatus and projector - A discharge lamp lighting apparatus comprises a discharge lamp and a power supply the discharge lamp can be switched between a steady power lighting mode, which drives the discharge lamp by an alternating current in which first and second polarities are repeated by turns, and a low power lighting mode, which drives the discharge lamp at 50% or less of the alternating current of the steady power lighting mode, and the alternating current comprises a first time unit, which has a time width t | 03-17-2011 |