Light source apparatus and projector

Patent metadata

Field	Value
Publication number	US-9939718-B2
Application number	US-201313928712-A
Country	US
Kind code	B2
Filing date	Jun 27, 2013
Priority date	Jul 12, 2012
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

A light source apparatus includes a polarization conversion element, a fluorescent substance and a light source element. The polarization conversion element has a p/s-polarizing beam splitter film to separate polarization components of incident light into p-polarization component and s-polarization component. The fluorescent substance emits visible light as the incident light that is incident on the p/s-polarizing beam splitter film, which visible light is generated by that the fluorescent substance is excited by excitation light, and has a wavelength of longer wavelength region than a wavelength of the excitation light. The light source element emits a laser beam having a predetermined wavelength as the excitation light to irradiate the fluorescent substance with the excitation light so that a laser beam having a polarization plane between the polarization plane of p-polarized light and the polarization plane of s-polarized light exiting from the fluorescent substance is emitted as the incident light.

First claim

What is claimed is:

1. A light source apparatus for emitting visible light of uniform intensity, comprising:
a polarization conversion element having a p/s-polarizing beam splitter film capable of separating polarization components of incident light into p-polarization components and s-polarization components for transmission in a transmit direction by transmitting the p-polarization components or the s-polarization components of the incident light in the transmit direction and reflecting the other polarization components in a reflecting direction and re-reflecting the reflected components to transmit the re-reflected components in the same direction as the transmit direction;
a fluorescent substance capable of emitting visible light having p-polarization components and s-polarization components as the incident light that is incident on the p/s-polarizing beam splitter film by exciting the fluorescent substance with excitation light of a predetermined wavelength, the emitted visible light having a wavelength in a wavelength region longer than the wavelength of the excitation light;
a light source element capable of emitting a laser beam with p-polarization components and s-polarization components, the laser beam having the predetermined wavelength as the excitation light to irradiate the fluorescent substance, the laser beam having a polarization plane and at least a part of the laser beam being emitted from the fluorescent substance and incident on the p/s-polarizing beam splitter film with a ratio of the polarization components of the incident laser beam determined by an angle θ of the polarization plane at which the laser beam is emitted, wherein θ is the angle between the polarization plane of the emitted laser beam and a reference polarization plane, wherein the reference polarization plane is between the polarization plane of the p- polarization components and the polarization plane of the s- polarization components emitted from the fluorescent substance; and
a supporting member configured to support the light source element so that the angle θ between the polarization plane of the laser beam emitted by the light source element and the reference polarization plane is −20°≤θ≤20°, and the reference polarization plane is a polarization plane in which the p-polarization component of the light emitted from the fluorescent substance and the s-polarization component of the light emitted from the fluorescent substance are in a ratio of 1:1.

2. A projector comprising:
a light source apparatus for emitting light of uniform intensity and which includes
a polarization conversion element having a p/s-polarizing beam splitter film capable of separating polarization components of incident light into p-polarization components and s-polarization components for transmission in a transmit direction by transmitting the p-polarization components or the s-polarization components of the incident light in the transmit direction and reflecting the other polarization components in a reflecting direction and re-reflecting the reflected components to transmit the re-reflected components in the same direction as the transmit direction;
a fluorescent substance capable of being excited with excitation light to emit visible light having p-polarization components and s-polarization components as the incident light; and
a light source element capable of emitting as the excitation light a laser beam with p-polarization components and s-polarization components, the laser beam having a predetermined wavelength in the blue wavelength region or in a shorter wavelength region and irradiating the fluorescent substance with the excitation light so that a laser beam having a polarization plane between the polarization plane of p-polarized light and the polarization plane of s-polarized light is emitted as the excitation light and at least a part of the laser beam is emitted from the fluorescent substance and incident on the p/s-polarizing beam splitter film with a ratio of the p-polarization components to the s-polarization components of the incident laser beam determined by an angle θ of the polarization plane at which the laser beam is emitted, wherein θ is the angle between the polarization plane of the emitted laser beam and a reference polarization plane, wherein the reference polarization plane is between the polarization plane of the p-polarization component and the polarization plane of the s-polarization component emitted from the fluorescent substance; a supporting member configured to support the light source element so that the angle θ between the polarization plane of the laser beam emitted by the light source element and the reference polarization plane is −20°≤θ≤20°; and the reference polarization plane is a polarization plane in which the p-polarization component of the light emitted from the fluorescent substance and the s-polarization component of the light emitted from the fluorescent substance are in a ratio of 1:1; and

an image generating element configured to generate an image using the light emitted from the light source apparatus.

Assignees

• Sony Corp

Inventors

• Matsumoto Kazuya

Classifications

• G02B27/283

  used for beam splitting or combining · CPC title

• G03B21/204 Primary

  using secondary light emission, e.g. luminescence or fluorescence (using different colours G03B33/00; if related to video signals H04N9/3197) · CPC title

• G02B27/285

  comprising arrays of elements, e.g. microprisms · CPC title

• G03B21/2073

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