Patent ID: 8476814
Filing Date: 2013-07-02
Classification: G03B,H01J

Abstract:
1. A lamp device, comprising: a high-discharge lamp and a concave reflection mirror for reflecting a light therefrom, in which the high-pressure discharge lamp has an arc tube having seal portions formed on both forward and backward ends in the direction of a tube axis interposing a discharge bulb therebetween where electrode assemblies are inserted from both of the seal portions and the seal portions are airtightly sealed in a state that discharge electrode tops are opposed each other in the discharge bulb, and is disposed in a state of aligning the tube axis with the optical axis of the concave reflection mirror, and a portion of lights emitted from the discharge bulb to the periphery thereof in the forward and backward directions for a predetermined range of angle is reflected at the concave reflection mirror and illuminated to a light collection area of a predetermined size formed forward of the lamp, wherein a prism surface is formed to the outer peripheral surface of the discharge bulb at an angle for refracting or reflecting at least a portion of lights emitted from the discharge bulb that is not reflected at the concave reflection mirror to the light collection area, and the concave reflection mirror is formed with a reflection surface in a concave curved shape rotating around a Z axis as a central axis while defining the optical axis thereof as the Z axis, and two axes perpendicular thereto as an X axis and an Y axis in which the peripheral surface of the reflection mirror is cut along two planes in parallel with a ZX surface with the Z axis as an axis of symmetry to form two arched recesses opposed each other in the peripheral surface of the reflection mirror, and the prism surfaces are formed in symmetry with respect to the ZX surface at a portion crossing the optical beam emitted from the discharge bulb to the recesses for a predetermined range of angle in the direction of the Y axis.