US-12619140-B2 - Light source apparatus and projector

US12619140B2US 12619140 B2US12619140 B2US 12619140B2US-12619140-B2

Abstract

A light source apparatus according to an aspect of the present disclosure includes a first light source section that outputs first light containing a first polarized component and a second polarized component, a second light source section that outputs second light, a wavelength converter that converts the first light into third light, a light combiner that combines the first light, the second light, and the third light, and a filter that attenuates light of the third wavelength band. The light combiner reflects the first polarized component and transmits the second polarized component to cause one of the first polarized component and the second polarized component to exit toward the wavelength converter, and transmits the first light and the second light or the third light and reflects the third light or the first light and the second light. The filter is movable.

Inventors

Wataru YASUMATSU
Yuichiro MATSUMOTO
Naoya SHINDO

Assignees

SEIKO EPSON CORPORATION

Dates

Publication Date: 20260505
Application Date: 20230929
Priority Date: 20220930

Claims (12)

1 . A light source apparatus comprising: a first light source section that outputs first light that belongs to a first wavelength band containing a first polarized component and a second polarized component different from the first polarized component; a second light source section that outputs second light that belongs to a second wavelength band different from the first wavelength band; a wavelength converter that converts the first light into third light that belongs to a third wavelength band different from the first wavelength band and second wavelength band; a light combiner that combines the first light, the second light, and the third light with one another and outputs combined light; and a filter that receives the third light and attenuates light that belongs to a wavelength band that is part of the third wavelength band, wherein: the light combiner reflects light formed of the first polarized component and transmits light formed of the second polarized component out of the first light outputted from the first light source section, the light combiner emits one of the light formed of the first polarized component and the light formed of the second polarized component toward the wavelength converter, the light combiner transmits one of (i) the first light re-entering the light combiner and the second light, or (ii) the third light, and reflects the other of (i) the first light re-entering the light combiner and the second light, or (ii) the third light, the filter is movable between a first position where the third light passes through the filter and a second position where the third light does not pass through filter, the light combiner combines the third light incident along a first direction from the wavelength converter with the second light incident along a second direction that intersects with the first direction from the second light source section, and the filter is provided between the light combiner and the wavelength converter.
2 . The light source apparatus according to claim 1 , further comprising a diffuser that diffuses the first light and the second light.
3 . The light source apparatus according to claim 2 , wherein the diffuser is disposed between the light combiner and the second light source section, and the diffuser has a configuration in which a first surface on which the first light reflected off the light combiner is incident has a diffusion structure that diffuses the first light and the second light, and a second surface opposite from the first surface has a reflection film that reflects the first light and transmits the second light.
4 . The light source apparatus according to claim 1 , further comprising a parallelizer provided at a light incident side of the filter and substantially parallelizing the third light.
5 . The light source apparatus according to claim 1 , wherein a light incident surface of the filter intersects with a chief ray of the third light at an angle different from 90 degrees.
6 . The light source apparatus according to claim 1 , wherein the first light source section includes a first light emitter that emits the first light, and a first phase retarder that is disposed between the first light emitter and the light combiner and imparts a phase retardation to the first light, the first light emitted from the light combiner is incident on the wavelength converter, and the first phase retarder is rotatable around an axis that intersects with a light incident surface of the first phase retarder.
7 . The light source apparatus according to claim 1 , further comprising a controller that controls a value of current supplied to the first light source section in such a way that the current value in a state in which the filter is located at the first position and the current value in a state in which the filter is located at the second position differ from each other.
8 . The light source apparatus according to claim 7 , wherein the first light is blue light, the second light is red light, the third light is green light, and the controller performs control in such a way that the value of the current supplied to the first light source section when the filter is located at the first position is greater than the value of the current supplied to the first light source section when the filter is located at the second position.
9 . The light source apparatus according to claim 8 , wherein the controller further performs control in such a way that the value of the current supplied to the second light source section when the filter is located at the first position is smaller than the value of the current supplied to the second light source section when the filter is located at the second position.
10 . The light source apparatus according to claim 1 , further comprising: a first optical element that is provided at a light incident side of the filter and divides the combined light that exits out of the light combiner into a first luminous flux and a second luminous flux; and a second optical element that is provided at a light exiting side of the filter and has a first light incident region on which the first luminous flux is incident and a second light incident region on which the second luminous flux is incident, wherein the filter includes a first filter section on which the first luminous flux is incident and a second filter section on which the second luminous flux is incident, when the filter is placed at the first position, the first filter section is placed at a position where the first filter section faces the first light incident region of the second optical element, and the second filter section is placed at a position where the second filter section faces the second light incident region of the second optical element, and when the filter is placed at the second position, the first filter section is placed at a position where the first filter section faces a region between the first light incident region and the second light incident region of the second optical element.
11 . The light source apparatus according to claim 1 , wherein the first light incident on the filter has an elliptical cross-sectional shape having a major axis and a minor axis, the third light incident on the filter has a circular cross-sectional shape, a length of a diameter of the cross-sectional shape of the third light is substantially equal to one of a length of a diameter of the cross-sectional shape of the first light in a direction along the major axis and a length of the diameter of the cross-sectional shape of the first light in a direction along the minor axis, and the filter is movable in a direction along the axis along which the two lengths are substantially equal to each other out of the direction along the major axis and the direction along the minor axis.
12 . A projector comprising: the light source apparatus according to claim 1 ; a light modulator that modulates light output from the light source apparatus and containing the combined light in accordance with image information; and a projection optical apparatus that projects the light modulated by the light modulator.

Description

The present application is based on, and claims priority from JP Application Serial Number 2022-157650, filed Sep. 30, 2022, the disclosure of which is hereby incorporated by reference herein in its entirety. BACKGROUND 1. Technical Field The present disclosure relates to a light source apparatus and a projector. 2. Related Art As a light source apparatus used in a projector, there has been a proposed light source apparatus using fluorescence emitted from a phosphor when the phosphor is irradiated with excitation light output from a light emitter. For example, JP-A-2014-186115 described below discloses a light source apparatus including a first light source that outputs blue light, a phosphor that is excited by the blue light to emit green light, a second light source that outputs red light, a first dichroic mirror that transmits the blue light and reflects the green light, and a second dichroic mirror that transmits the blue light and the green light and reflects the red light. JP-A-2014-186115 is an example of the related art. In recent projectors, there is a need in some cases for a function that allows a user to select a color-reproducibility-oriented mode or a luminance-oriented mode. To achieve such a projector, it is necessary to provide a light source apparatus that allows switching between the color-reproducibility-oriented mode and the luminance-oriented mode. When a phosphor is used to generate specific color light, for example, green light, as in JP-A-2014-186115, a decrease in the purity of the green light is inevitable as compared with the purity achieved by a light source apparatus using a green laser. As a result, the color reproducibility deteriorates in a projector including a light source apparatus of this type. JP-A-2014-186115 describes that narrow-band filtering achieved by the second dichroic mirror allows effective use of red light, but the light source apparatus described in JP-A-2014-186115 has a problem of incapability of switching between the color-reproducibility-oriented mode and the luminance-oriented mode. SUMMARY To solve the problem described above, a light source apparatus according to an aspect of the present disclosure includes a first light source section that outputs first light that belongs to a first wavelength band containing a first polarized component and a second polarized component different from the first polarized component, a second light source section that outputs second light that belongs to a second wavelength band different from the first wavelength band, a wavelength converter that converts the first light into third light that belongs to a third wavelength band different from the first and second wavelength bands, a light combiner that combines the first light, the second light, and the third light with one another and outputs the combined light, and a filter that receives the third light and attenuates light that belongs to a wavelength band that is part of the third wavelength band. The light combiner reflects light formed of the first polarized component and transmits light formed of the second polarized component out of the first light output from the first light source section to cause one of the light formed of the first polarized component and the light formed of the second polarized component to exit toward the wavelength converter, and transmits the first light and the second light or the third light and reflects the third light or the first light and the second light. The filter is movable between a first position where the third light passes through the filter and a second position where the third light does not pass through filter. A projector according to another aspect of the present disclosure includes the light source apparatus according to the aspect of the present disclosure, a light modulator that modulates light output from the light source apparatus and containing the combined light in accordance with image information, and a projection optical apparatus that projects the light modulated by the light modulator. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of a projector according to a first embodiment. FIG. 2 is a schematic configuration diagram of a light source apparatus according to the first embodiment. FIG. 3 is a graph showing the spectral characteristics of a first optical film of a filter. FIG. 4 is a graph showing the spectral characteristics of a second optical film of the filter. FIG. 5 is a graph showing the spectral characteristics of a third optical film of a light combiner. FIG. 6 is a graph showing the spectral characteristics of a fourth optical film of the light combiner. FIG. 7 is a graph showing the spectral characteristics of a first optical film of a filter according to a variation. FIG. 8 is a graph showing the spectrum of the light emitted from each light source section. FIG. 9 is a graph showing the spectrum of green light after passing through the filter. FIG. 10 shows the