Light source apparatus

Abstract

A light source apparatus comprises a mercury lamp having an arc tube having a light emitting portion and sealing portions extending from both sides of the light emitting portion, respectively and, a concave reflection mirror which reflects light emitting from the discharge lamp in a predetermined direction, and a front glass made from light transmissive material, which is arranged in an opening side of the concave reflection mirror, wherein a reflective surface of the concave reflection mirror is made of metal, and, wherein a reflective film which reflects infrared light and ultraviolet light, is formed on a surface of the front glass, and the infrared light and ultraviolet light which emitted from the extra-high mercury discharge lamp are reflected on the front glass so as to be returned to part of electrodes of the extra-high pressure mercury lamp or between the electrodes.

Description

BRIEF DESCRIPTION OF DRAWINGS

Other features and advantages of the present light source apparatus will be apparent from the ensuing description, taken in conjunction with the accompanying drawings, in which:

FIG. 1A is a cross sectional view of a light source apparatus, taken along a plan including the optical axis thereof;

FIG. 1B is an enlarged view of a portion A of FIG. 1A;

FIGS. 2A and 2B are conceptual diagrams for explaining the technical meaning of embodiments;

FIG. 3A is a sectional view of another embodiment of a light source apparatus, taken along a plan including the optical axis thereof;

FIG. 3B is an enlarged view of a portion B of FIG. 3B;

FIG. 4A is a cross sectional view of still another embodiment of the light source apparatus, taken along a plan including the optical axis;

FIG. 4B is an enlarged view of a portion C of FIG. 4A.

FIGS. 5A, 5B, and 5C are cross sectional views, taken along a plan including the optical axis of a conventional light source apparatus; and

FIG. 6 is a conceptual diagram for explaining the technical meaning of embodiment.

Claims

1. A light source apparatus comprising: an extra-high pressure mercury lamp having an arc tube having a light emitting portion and sealing portions extending from both sides of the light emitting portion, respectively, in which a pair of electrodes facing each other is provided and, mercury of 0.15 mg/mm3 or more is enclosed,a concave reflection mirror which reflects light emitting from the discharge lamp in a predetermined direction and which surrounds the extra-high pressure mercury lamp, anda front glass made from light transmissive material, which is arranged in an opening side of the concave reflection mirror,wherein a reflective surface of the concave reflection mirror is made of metal, and,wherein a reflective film which reflects infrared light and ultraviolet light, is formed on a surface of the front glass, and the infrared light and ultraviolet light which emitted from the extra-high mercury discharge lamp are reflected on the front glass so as to be returned to part of electrodes of the extra-high pressure mercury lamp or between the electrodes.

2. The light source apparatus according to claim 1, wherein the reflective film is formed on a surface of the front glass in extra-high pressure mercury lamp side thereof.

3. The light source apparatus according to claim 1, wherein the concave reflection mirror has a spheroidal shape in which part of an ellipse is included in a sectional view thereof taken along a plane including an optical axis, and the front glass has a concave section and a plane section in which the reflective film is provided so as to have a concave shape as a whole, and the concave section is located in the extra-high-pressure-mercury-lamp side thereof and the plane section is located outside of the concave reflection mirror.

4. The light source apparatus according to claim 1, wherein the concave reflection mirror has a spheroidal shape in which part of an ellipse is included in a sectional view thereof taken along a plane including an optical axis, and the front glass has a curved portion which curves toward the high pressure mercury lamp side.

5. The light source apparatus according to claim 2, wherein the concave reflection mirror has a spheroidal shape in which part of an ellipse is included in a sectional view thereof taken along a plane including an optical axis, and the front glass has a curved portion which curves toward the high pressure mercury lamp side.