Projector having a light-emitting element, image forming unit and reflecting member

Patent metadata

Field	Value
Publication number	US-9348208-B2
Application number	US-81252308-A
Country	US
Kind code	B2
Filing date	Nov 10, 2008
Priority date	Jan 22, 2008
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

A projector includes: a solid-state light emitting element that emits light; a projection image forming unit that includes an effective area in order to form a projection image; and a reflecting member disposed between the solid-state light emitting element and the projection image forming unit, wherein: the reflecting member reflects part of the light emitted from the solid-state light emitting element and thus redirects the part of the light to travel back to the solid-state light emitting element, the part of the light not entering the effective area.

First claim

The invention claimed is:

1. A projector, comprising:
a solid-state light emitting element that emits light;
a projection image forming unit that includes an effective area in order to form a projection image; and
a reflecting member disposed between the solid-state light emitting element and the projection image forming unit,
wherein:
the solid-state light emitting element includes a light emitting portion which emits a first light, and a phosphorescent substance provided on the light emitting portion, which emits a second light that is a phosphorescent light excited by the first light and emanating from the phosphorescent substance, and emits both the first and the second light toward the effective area;
the reflecting member reflects part of the light emitted from the solid-state light emitting element and thus redirects the part of the light to travel back to the solid-state light emitting element, the part of the light not entering the effective area;
the projection image forming unit is a reflective image forming element that includes a polarization splitter element disposed at a front thereof;
the reflecting member is fixed on an entry surface of the polarization splitter element; and
the first light among the part of the light reflected and redirected to the solid state light-emitting element by the reflecting member reenters the phosphorescent substance provided on the light-emitting element and excites the phosphorescent substance.

2. The projector according to claim 1 , wherein:
the reflecting member includes an opening formed in a shape corresponding to a shape of the effective area; and
the solid-state light emitting element emits the light toward the projection image forming unit via the opening.

3. The projector according to claim 1 , wherein:
the reflecting member includes a first reflecting portion and a second reflecting portion which are set apart from each other over a predetermined distance corresponding to the effective area.

4. The projector according to claim 1 , further comprising:
an illumination optical system disposed between the polarization splitter element and the solid-state light emitting element that converts the light emitted from the solid-state light emitting element to a substantially parallel light.

5. The projector according to claim 1 , wherein:
the reflecting member has an optical power so as to ensure that the light reflected thereat returns to the light-emitting element through the same optical path as the light initially reached the reflecting member.

Assignees

• Suga Akinobu
• Uchiyama Takayuki
• Fujinawa Nobuhiro
• Nikon Corp

Inventors

• Suga Akinobu
• Uchiyama Takayuki
• Fujinawa Nobuhiro

Classifications

• G03B21/2066

  Reflectors in illumination beam (in projection beam G03B21/28) · CPC title

• G03B21/2073

  Polarisers in the lamp house (peculiar to electronic spatial light modulators H04N9/3197) · CPC title

• G03B21/208

  Homogenising, shaping of the illumination light · CPC title

• G03B21/28 Primary

  Reflectors in projection beam {(in illumination beam G03B21/2066)} · CPC title