HIGH PRESSURE MERCURY LAMP AND LAMP UNIT

摘要

PURPOSE: A high pressure mercury lamp is provided to achieve a high pressure mercury lamp that is not blackened even at an operating pressure of more than 20 MPa. CONSTITUTION: A high pressure mercury lamp includes a luminous bulb(1) in which at least mercury is enclosed inside the bulb, and a pair of sealing portions(2) that retain airtightness of the luminous bulb. At least one of the sealing portions(2) has a first glass portion extending from the luminous bulb and a second glass portion provided in at least a portion inside the first glass portion, and the one of the sealing portions has a portion to which a compressive stress is applied. Furthermore, a heating wire(10) is provided at least at part of the luminous bulb and the pair of sealing portions. Preferably, the amount of the enclosed mercury is 230 mg/cm¬3 or more based on the volume of the luminous bulb.