Projection type display apparatus and lighting device

Patent metadata

Field	Value
Publication number	US-9693026-B2
Application number	US-201514593052-A
Country	US
Kind code	B2
Filing date	Jan 9, 2015
Priority date	Jan 15, 2014
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

In a projection type display apparatus, a lighting device includes two reflection type cutoff filters (first cutoff filter and reflective second cutoff filter) which block out ultraviolet range light on an output optical path from a light source. A cut on wavelength of the second cutoff filter on the front side is longer than that of the first cutoff filter on the rear side. The two cutoff filters are formed on planar-shaped first faces of a first integrator lens and a second integrator lens. For this reason, both input faces of the two cutoff filters are orthogonal to an apparatus optical axis.

First claim

What is claimed is:

1. A projection type display apparatus comprising:
a light source;
a liquid crystal panel which includes a liquid crystal layer between a first substrate and a second substrate, and modulates light which is output from the light source;
a projection optical system which projects the modulated light which is output from the liquid crystal panel;
a first cutoff filter which reflects ultraviolet range light and is arranged between the light source and the liquid crystal panel; and
a second cutoff filter which reflects the ultraviolet range light, is arranged between the light source and the first cutoff filter, and has a cut on wavelength longer than that of the first cutoff filter,
wherein transmissivity of the first cutoff filter is equal to or more than 90% when light with a wavelength of which transmissivity of the second cutoff filter is 10% is radiated to the first cutoff filter.

2. The projection type display apparatus according to claim 1 ,
wherein an input face of at least one of the first cutoff filter and the second cutoff filter is orthogonal to an apparatus optical axis which reaches the liquid crystal panel from the light source.

3. The projection type display apparatus according to claim 1 ,
wherein at least one of the first cutoff filter and the second cutoff filter is provided with an optical element on the input face side or an output face side.

4. The projection type display apparatus according to claim 3 ,
wherein the optical element has a curved face.

5. The projection type display apparatus according to claim 1 ,
wherein the transmissivity of the second cutoff filter is equal to or less than 0.1% when light with a cut on wavelength of which transmissivity of the first cutoff filter is 50% is radiated to the second cutoff filter.

6. The projection type display apparatus according to claim 1 ,
wherein the liquid crystal panel includes a first inorganic alignment film which is formed on a liquid crystal panel side of the first substrate, and a second inorganic alignment film which is formed on a liquid crystal panel side of the second substrate.

7. The projection type display apparatus according to claim 1 ,
wherein the first cutoff filter and the second cutoff filter are formed of dielectric multilayered films.

8. A lighting device comprising:
a light source;
a first cutoff filter which reflects ultraviolet light and is arranged on an output optical path from the light source; and
a second cutoff filter which reflects the ultraviolet range light, is arranged between the light source and the first cutoff filter, and has a cut on wavelength longer than that of the first cutoff filter,
wherein transmissivity of the first cutoff filter is equal to or more than 90% when light with a wavelength of which transmissivity of the second cutoff filter is 10% is radiated to the first cutoff filter.

9. A projection type display apparatus comprising:
a light source;
a liquid crystal panel which includes a liquid crystal layer between a first substrate and a second substrate, and modulates light which is output from the light source;
a projection optical system which projects the modulated light which is output from the liquid crystal panel;
a first cutoff filter which reflects ultraviolet range light and is arranged between the light source and the liquid crystal panel; and
a second cutoff filter which reflects the ultraviolet range light, is arranged between the light source and the first cutoff filter, and has a cut on wavelength longer than that of the first cutoff filter,
wherein the transmissivity of the second cutoff filter is equal to or less than 0.1% when light with a cut on wavelength of which transmissivity of the first cutoff filter is 50% is radiated to the second cutoff filter.

Assignees

• Seiko Epson Corp

Inventors

• Tomikawa Naoki
• Hirota Takenori
• Kurosawa Ryuichi

Classifications

• H04N9/3158 Primary

  for controlling the spectrum · CPC title

• H04N9/3144

  Cooling systems (cooling of liquid crystal cells in general G02F1/133382; cooling of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/16) · CPC title

• G02B5/283

  designed for the ultraviolet · CPC title

• G02B27/102 Primary

  for generating a colour image from monochromatic image signal sources · CPC title

• G03B21/006

  using LCD's · CPC title