High-intensity discharge lamp and high-intensity discharge lamp operating apparatus

A high-intensity discharge lamp operating apparatus, comprising:

• a high-intensity discharge lamp comprising:
• an arc tube including a pair of electrodes opposed to each other therein;
• and a trigger wire made of a conductive material provided in an outer circumference of the arc tube;
• an operating circuit for operating the high-intensity discharge lamp,
• wherein the trigger wire is not electrically connected to either one of the pair of electrodes,
• the operating circuit comprises:
• driving voltage applying means for applying a driving voltage for maintaining discharge after the discharge is started between the pair of electrodes;
• and
• start-up voltage applying means for applying a start-up voltage for starting discharge between the pair of electrodes,
• wherein the trigger wire is electrically connected to the driving voltage applying means and each of the pair of electrodes is electrically connected to the driving voltage applying means, wherein the start-up voltage applying means comprises a timer for controlling the start-up voltage applying means so as to apply the start-up voltage to the trigger wire for a predetermined time during start-up.

A high-intensity discharge lamp operating apparatus, comprising:

• a high-intensity discharge lamp comprising:
• an arc tube including a pair of electrodes opposed to each other therein;
• and a trigger wire made of a conductive material provided in an outer circumference of the arc tube;
• an operating circuit for operating the high-intensity discharge lamp,
• wherein the trigger wire is not electrically connected to either one of the pair of electrodes,
• the operating circuit comprises:
• driving voltage applying means for applying a driving voltage for maintaining discharge after the discharge is started between the pair of electrodes;
• and
• start-up voltage applying means for applying a start-up voltage for starting discharge between the pair of electrodes,
• wherein the trigger wire is electrically connected to the driving voltage applying means and each of the pair of electrodes is electrically connected to the driving voltage applying means, wherein the start-up voltage applying means comprises:
• detecting means for detecting that lamp operation is started by discharge between the pair of electrodes;
• and
• controlling means for stopping application of the start-up voltage when the detecting means detects that lamp operation is started.