JP2017215527A - Illumination light switching mechanism, projector with the mechanism, and illumination light switching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination light switching mechanism which generates an additional light only during a high luminance mode, a projector with the mechanism, and an illumination light switching method.SOLUTION: An illumination light switching mechanism comprises: a light source 201 which outputs a linearly polarized light in a first color; a polarization beam splitter 206; a phosphor wheel 204 including a reflection plane on which an incident light is reflected and a reflection light is generated, and a phosphor portion in which a fluorescent light in a second color is generated by the incident light; a 1/4λ plate 208 which is provided between the polarization beam splitter and the phosphor wheel; and a polarization beam splitter drive mechanism for rotating the polarization beam splitter and bringing its reflection plane into a first state where the output light of the light source is reflected in a first direction and a second state where the output light of the light source is output toward the phosphor wheel. The polarization beam splitter outputs the reflection light and the fluorescent light in the second color which are generated in the phosphor wheel during the second state, in the first direction.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an illumination light switching mechanism, a projector including the mechanism, and an illumination light switching method.

  In recent years, the use of mercury lamps has been regulated from the viewpoint of environmental pollution. As a light source that replaces the mercury lamp, there is a solid-state light source projector that excites a phosphor by LD (Laser Diode) light using a component that combines the phosphor with a disk-shaped substrate, generates fluorescence, and uses the fluorescence. It has been developed and is now widely seen in the market (see, for example, Patent Document 1).

  On the other hand, projectors are increasingly used in various environments such as outdoor use, and accordingly, projectors capable of projecting with various luminances are demanded.

There are various means for making the brightness variable, but in normal times when used as a normal mode, projection is performed with three colors of R / G / B (red / green / blue) light formed by a solid light source, and higher brightness is achieved. In the required high luminance mode, it is one of the additional green additional lights (hereinafter referred to as G + light) formed from a solid light source.

Patent No. 5618130

  As described above, when high luminance is realized by adding G + light, G + light that is not used even in the normal mode is generated depending on the configuration of the optical system. In such an optical system, when unused G + light is processed as unnecessary light in the apparatus, problems such as a decrease in image quality due to the generation of stray light and an increase in temperature due to heat generation may occur.

  The present invention realizes an illumination light switching mechanism that generates G + light only in the high luminance mode, a projector including the mechanism, and an illumination light switching method.

An illumination light switching mechanism according to the present invention includes a light source that outputs linearly polarized light of a first color,
A polarizing beam splitter;
A phosphor wheel comprising a reflecting surface that reflects incident light to generate reflected light, and a phosphor portion that generates fluorescence of a second color by the incident light;
A quarter-lambda plate provided between the polarizing beam splitter and the phosphor wheel;
A first state in which the polarization beam splitter is rotated to reflect the output light of the light source in a first direction on the reflection surface thereof, and a second state in which the output light of the light source is output toward the phosphor wheel. A polarization beam splitter driving mechanism to be in a state,
The polarizing beam splitter outputs the reflected light generated by the phosphor wheel and the second color fluorescence in the first direction in the second state.

A projector according to the present invention is a projector including the illumination light switching mechanism described above,
A light source unit that generates illumination light of the second color and illumination light of the third color;
A first spatial light modulation element illuminated by illumination light output by the illumination light switching mechanism;
A second spatial light modulation element illuminated by the illumination light of the second color generated by the light source unit;
A third spatial light modulation element illuminated by the illumination light of the third color generated by the light source unit;
A cross dichroic prism that synthesizes each image light obtained by the first to third spatial light modulators;
A projection lens that projects image light synthesized by the cross dichroic prism;
A switching signal indicating that the polarizing beam splitter is set to the first state or the second state and a video signal are input, and the polarizing beam splitter is moved by the polarizing beam splitter driving mechanism according to the switching signal. In the first state or the second state, when the polarization beam splitter is in the first state, the first spatial light modulation element is caused to form an image of the first color indicated in the video signal, and the polarization beam A control unit that causes the first spatial light modulator to form a first color image and a second color image indicated by the video signal when the splitter is in the second state; To do.

The illumination light switching method of the present invention includes a light source that outputs linearly polarized light of a first color,
A polarizing beam splitter;
A phosphor wheel comprising a reflecting surface that reflects incident light to generate reflected light, and a phosphor portion that generates fluorescence of a second color by the incident light;
An illumination light switching method performed by an illumination light output mechanism comprising a quarter-λ plate provided between the polarizing beam splitter and the phosphor wheel,
A polarization beam splitter driving mechanism rotates the polarization beam splitter so that the reflection surface reflects the output light of the light source in a first direction and the output light of the light source to the phosphor wheel. One of the second states to be output,
The polarization beam splitter outputs the reflected light and the second color fluorescence generated by the phosphor wheel in the first direction in the second state.

  The present invention is configured such that G + light (second color fluorescence) is emitted only when the polarizing beam splitter is used as a high-luminance mode in which the second state is set. Problems such as a temperature rise due to a decrease or heat generation can be prevented, and further, effects such as energy saving and longer life can be expected.

It is a block diagram which shows the structure of the optical system of one Embodiment of the projector by this invention. It is a figure which shows the fluorescent substance wheel 204 in FIG. It is a figure which shows the light which generate | occur | produces according to the incident position to the fluorescent substance wheel. It is a figure which shows the light which generate | occur | produces according to the incident position to the fluorescent substance wheel. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 1st Embodiment is a normal mode. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 1st Embodiment is a high-intensity mode. It is a figure which shows the structure of the control part which controls the optical system of 1st Embodiment. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 2nd Embodiment is a normal mode. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 2nd Embodiment is a high-intensity mode. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 3rd Embodiment is a normal mode. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 3rd Embodiment is a high-intensity mode. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 4th Embodiment is a normal mode. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 4th Embodiment is a high-intensity mode. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 5th Embodiment is a normal mode. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 5th Embodiment is a high-intensity mode. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 6th Embodiment is a normal mode. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 6th Embodiment is a high-intensity mode. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 7th Embodiment is a normal mode. It is a figure which shows the reflection direction of the S polarization component by a polarizing beam splitter when the projection mode in 7th Embodiment is a high-intensity mode. It is a figure for demonstrating a mechanism component precision. It is a figure for demonstrating a mechanism component precision.

  Next, embodiments of the present invention will be described with reference to the drawings.

First Embodiment FIG. 1 is a block diagram showing a configuration of an optical system of an embodiment of a projector according to the present invention.

  The projector according to this embodiment is a three-plate type that irradiates three color lights formed by a solid-state light source onto a spatial modulation element corresponding to each color light, and enlarges and projects an image of the element surface with a projection lens. Brightness is increased by using four lights of three colors with G + light added to normal light using three lights of three colors of G / B and three lights used in normal mode. It has two types of projection modes, an improved high brightness mode.

  As shown in FIG. 1, the projector according to the present embodiment includes a first light source unit 100 and a second light source unit 200 that emit illumination light, and an output of the first light source unit 100 and the second light source unit 200. An illumination unit 300 that uses uniform R / G / B illumination light as an incident light, an imaging unit 400 that generates and synthesizes an R / G / B image obtained by spatially modulating the R / G / B illumination light, and a projection lens 500 It is composed of

  The first light source unit 100 includes a semiconductor laser 101 that emits blue laser light, lenses 102, 103, 105, and 107, a phosphor wheel 104 around which a phosphor that generates yellow fluorescence is provided, and a dichroic mirror 106. It is configured.

  The dichroic mirror 106 reflects blue light (B light) and allows yellow light (Y light) to pass therethrough. The blue laser light emitted from the semiconductor laser 101 passes through the lenses 102 and 103 and then passes through the lenses 102 and 103. The light is reflected and enters the phosphor wheel 104 through the lens 105. The phosphor wheel 104 is rotated by a motor (not shown), and a phosphor is formed at a position where the blue laser beam is irradiated. The phosphor is excited by the irradiation of the blue laser beam to emit red light (R light). ) And green light (G light), yellow fluorescence (Y light) is generated. The Y light enters the illumination unit 300 through the lens 105, the dichroic mirror 106, and the lens 107.

  The second light source unit 200 includes a semiconductor laser 201 that emits blue laser light, lenses 202, 203, 205, 207, a phosphor wheel 204, a polarization beam splitter 207, a quarter wavelength plate 208, and a diffusion plate 209. Has been.

  The blue laser light emitted from the semiconductor laser 201 passes through the lenses 202 and 203 and the diffusion plate 209 and then enters the polarization beam splitter 206. The polarization beam splitter 206 transmits a P-polarized component and reflects an S-polarized component for blue laser light. Moreover, it has the characteristic which permeate | transmits green light irrespective of polarization.

  The projector according to the present embodiment includes a normal mode and a high-brightness mode that has higher brightness than the normal mode as projection modes. In the polarization beam splitter 206, the incident surface of the blue laser light is switched by a polarization beam splitter driving mechanism such as a stepping motor or a rotary solenoid according to the projection mode, and the emission direction of the reflected S-polarized component is changed accordingly. It can be switched to the phosphor wheel 204 side or the anti-phosphor wheel 204 side. This switching is performed by rotating the optical component. Since switching involves rotation, when the direction of the reflecting surface is changed by changing the projection mode, the position of the reflecting surface may deviate as shown in FIG. As shown in FIG. 21, when the reflecting surface is deviated by θ ° from the optical design surface, the optical axis is deviated by 2θ °. For this reason, when a deviation occurs, it becomes difficult for the optical component on which the light beam reflected by the reflecting surface is incident to take in the configuration. That is, if the position of the moved reflecting surface deviates from the design surface, it causes a decrease in light utilization efficiency, which directly leads to a decrease in the brightness of the projector. For this reason, it is desirable that the reflection surface be arranged on the optical design surface (θ = 0) when the arrangement is changed by the switching mechanism, but the reflection surface displacement (to the extent that the light utilization efficiency does not decrease compared to the optical design) In consideration of θ) and the accuracy of the mechanical parts, it is necessary to suppress θ to about ± 0.5 °. Here, the value of θ also varies depending on the distance between the polarizing beam splitter and the optical component.

  The phosphor wheel 204 is different from the phosphor wheel 104 in a state where the green phosphor is partially cut out by an arbitrary angle on a disk-shaped substrate having a reflecting surface as shown in FIG. A phosphor portion 2041 coated with a phosphor that generates green fluorescence (G + light) and a reflecting surface 2042 that reflects incident light are combined.

  S-polarized blue laser light is emitted from the semiconductor laser 201. The laser light passes through the lenses 202 and 203 and the diffusion plate 209 to be diffused light having a predetermined shape and is incident on the polarization beam splitter 206.

  When the polarization beam splitter 206 is switched to emit the S-polarized component to the phosphor wheel 204 side, and the blue laser light is irradiated to the phosphor portion 2041, the phosphor is blue as shown in FIG. Excited by the laser light irradiation, G + light is generated, passes through the polarization beam splitter 206, and enters the illumination unit 300.

  When the blue laser light is irradiated on the reflection surface 2042, the blue laser light reflected by the phosphor wheel 204 reenters the polarization beam splitter 206 as shown in FIG. Since the blue laser light at this time is converted to P-polarized light by passing through the quarter-wave plate 208 twice, it passes through the polarization beam splitter 206 and enters the illumination unit 300.

  The illumination unit 300 includes a mirror 301, a dichroic mirror 302, an integrator 304, a polarization conversion element 305, and a lens 306. Y light is incident on the illumination unit 300 from the first light source unit, and B light and G + light are incident in time series from the second light source unit 200. The dichroic mirror 302 reflects G light and transmits light of other wavelengths, reflects G light component of Y light incident from the first light source unit, and transmits R light component. The G light component is folded back by the mirror 301, made uniform by the integrator 304, the polarization direction is made uniform by the polarization conversion element 305, and enters the imaging unit 400 via the lens 306. The R light transmitted through the dichroic mirror 302, the B light and the G + light incident in time series from the second light source unit 200 enter the imaging unit 400 through an optical path different from the G light. An integrator 304, a polarization conversion element 305, and a lens 306 are provided.

  The imaging unit 400 includes spatial light modulation elements 401, 402, 403, mirrors 404, 405, and a cross dichroic prism 406. Spatial light modulators 401 to 403 that spatially modulate illumination light modulate color light to form image light of each color, and can use Liquid Crystal Display (LCD) or Digital Light Processing (DLP). . In addition, when using LCD, the polarization conversion element 305 for aligning a polarization direction like this embodiment is required, However, When using DLP, the polarization conversion element 305 is not essential.

  G light reflected by the mirrors 301 and 404 is incident on the spatial light modulation element 401. R light transmitted through the dichroic mirror 302 is incident on the spatial light modulator 402. B light and G + light from the second light source unit 201 reflected by the mirror 405 are incident on the spatial light modulation element 403. The image light formed by each spatial light modulation element is incident on the cross dichroic prism 406, synthesized, emitted toward the projection lens 500, and enlarged and projected by the projection lens 500.

  Next, switching of the reflection direction of the polarization beam splitter performed according to the projection mode in the second light source unit 200, which is a characteristic configuration of the present invention, will be described.

  FIG. 5 is a diagram showing the reflection direction of the S-polarized component by the polarizing beam splitter 206 when the projection mode is the normal mode, and FIG. 6 is a reflection of the S-polarized component by the polarizing beam splitter 206 when the projection mode is the high luminance mode. It is a figure which shows a direction.

  In the normal mode shown in FIG. 5, the polarization beam splitter 206 is in a state (first state) in which the S-polarized component is reflected toward the illumination unit 300 on the opposite side of the phosphor wheel 204. For this reason, the incident B light, which is blue laser light, enters the illumination unit 300 as it is.

  In the high luminance mode shown in FIG. 6, the polarization beam splitter 206 is rotated by the polarization beam splitter driving mechanism 210 to reflect the S-polarized component toward the phosphor wheel 204 (second state). For this reason, B light, which is incident blue laser light, enters the phosphor wheel 204, and G + light generated by the phosphor portion 2041 and B light reflected by the reflecting surface 2042 enter the illumination unit 300.

  As described above, the reflection surface of the polarization beam splitter 206 is switched by a mechanical component such as a stepping motor or a rotary solenoid. Since the position accuracy of the reflecting surface of the polarization beam splitter 206 needs to be within about ± 0.5 ° from the optical design position, a mechanical component having a step accuracy matching this accuracy is used. With this switching mechanism, G + light is emitted only when the projection mode is the high luminance mode, and no G + light is emitted when the projection mode is the normal mode. Therefore, unnecessary light is not generated, and the image quality caused by unnecessary light is reduced. There is no problem of heat generation.

  In the normal mode, it is not necessary to irradiate the phosphor wheel 204 with blue laser light for exciting the phosphor, and the time for which the phosphor is irradiated with the excitation light is reduced. Is promoted. Further, since it is not necessary to rotate the phosphor wheel 204 in the normal mode, energy saving of the entire apparatus can be achieved.

  FIG. 7 is a diagram illustrating a configuration of a control unit that controls the above-described optical system.

  The control unit 701 receives the video signal V1 and the projection mode signal B1 indicating the projection mode, and outputs control signals S1 to S8 for controlling each part of the optical system shown in FIG. 1 according to the contents of these signals. The control signals S1 and S2 control the semiconductor lasers 101 and 201 and control the output state of the laser light. In particular, the semiconductor laser 201 is controlled by the control signal S2 including its intensity.

  The control signals S3 to S5 control the spatial light modulation elements 401 to 403, and form an image for each color light indicated by the video signal V1 according to the video signal V1 and the projection mode signal B1.

  The control signals S6 and S7 control the rotation state of the phosphor wheels 104 and 204, and the control signal S8 switches the reflection direction of the S polarization component of the polarization beam splitter 206.

  Next, the control operation of the control unit 701 will be described.

  When the projection mode signal B1 indicates the normal mode, the control unit 701 reflects the S polarization component of the polarization beam splitter 206 toward the illumination unit 300 as shown in FIG. And At this time, since the phosphor wheel 204 is not irradiated with the semiconductor laser light, the phosphor wheel 204 is not rotated by the control signal S7. In addition, since the illumination unit 300 is not irradiated with G + light, the control signal S3 to S5 causes the spatial light modulation element 401 to display an image for G light, causes the spatial light modulation element 402 to display an image for R light, An image for B light is displayed on the spatial light modulator 403.

  When the projection mode signal B1 indicates the high luminance mode, the control unit 701 reflects the S polarization component of the polarization beam splitter 206 toward the phosphor wheel 204 as shown in FIG. It shall be. With respect to the phosphor wheel 204, the phosphor wheel 204 is rotated by the control signal S7. Thereby, as shown in FIG. 6, G + light and B light are emitted to the illumination unit 300 in time series. For this reason, an image for G light is displayed on the spatial light modulation element 401 and an image for R light is displayed on the spatial light modulation element 402 in accordance with the control signals S3 to S5, so that the G + light and the B light are emitted. An image for G light and an image for B light are displayed on the spatial light modulator 403.

  Since the B light in the high brightness mode has a shorter emission time than in the normal mode, when the semiconductor laser light is irradiated onto the reflecting surface 2042 of the phosphor wheel 204, the control signal S2 causes the semiconductor laser light to be emitted. It is assumed that the intensity is high and image light having the same light intensity as that of the blue image light in the normal mode can be obtained.

  In the present embodiment, the diffusion plate 209 is provided to spread the semiconductor laser light. Without the diffusing plate 209, the beam diameter of the semiconductor laser light becomes extremely small, the difference between the beam diameters of the G + light and the B light becomes large, and the magnitude of the color light transmitted to the imaging unit 400 via the illumination unit 300 This is because the spatial light modulation element 403 cannot be sufficiently illuminated. By providing the diffusion plate 209, the B light sufficiently illuminates the spatial light modulation element 403. In addition, since the polarization state of the semiconductor laser light may be somewhat disturbed by providing a diffusion plate, a polarization conversion element that aligns incident light with S-polarized light may be provided between the diffusion plate 209 and the polarization beam splitter 206.

Second Embodiment Next, a second embodiment of the present invention will be described.

  FIG. 8 and FIG. 9 are diagrams showing a main configuration of the second light source unit 200 in the second embodiment of the present invention.

  In the first embodiment, instead of the diffuser plate 209 provided between the lenses 202 and 203 and the polarization beam splitter 206, a diffuser plate 809 that is attached to the polarization beam splitter 206 and rotates together with the polarization beam splitter 206. Is provided.

  In the normal mode shown in FIG. 8, the B light exits from the polarization beam splitter 206 and then enters the diffuser plate 809. However, in the high brightness mode shown in FIG. 9, the polarization beam splitter 206 rotates. As a result, the diffusion plate 809 also moves, and the semiconductor laser light enters the diffusion plate 809 before entering the polarization beam splitter 206. In any mode, the number of times of passing through the diffusion plate and the effect of the diffusion plate are the same as in the first embodiment. Further, the behavior of the light beam after passing through the polarization beam splitter 206 and the method of changing the reflection surface of the polarization beam splitter 206 are the same as in the first embodiment.

Third Embodiment Next, a third embodiment of the present invention will be described.

  FIG. 10 and FIG. 11 are diagrams showing the main configuration of the second light source unit 200 in the third embodiment of the present invention.

  In this embodiment, in addition to the configuration of the first embodiment, a diffusion plate 1009 is inserted between the polarizing beam splitter 206 and the lens 207 (see FIG. 1) in the normal mode shown in FIG. Is. In the case of the high luminance mode shown in FIG. 11, the diffusion plate 1009 is not inserted.

  In the present embodiment, the semiconductor laser light is further diffused than in the first embodiment, and the uniformity is increased. The added diffusion plate 1009 is inserted or removed between the polarization beam splitter 206 and the lens 207 in accordance with the switching of the projection mode. Since the diffusion plate 1009 needs to be perpendicular to the optical axis, the diffusion plate 1009 is moved by a mechanism having an accuracy with which the inclination with respect to the optical axis is within about ± 0.1 °. The behavior of the light beam after passing through the polarizing beam splitter 206 and the method of changing the reflecting surface of the polarizing beam splitter 206 in the high luminance mode are the same as in the first embodiment.

  The optical path of the normal mode semiconductor laser light is shorter than that of the high brightness mode. For this reason, although the image quality is not affected, the semiconductor laser light may be propagated to the illumination unit 300 without being sufficiently diffused. In the present embodiment, the semiconductor laser light is further diffused by adding the diffusion plate 1009 only in the normal mode, and the uniformity of the illumination light is high.

Fourth Embodiment Next, a fourth embodiment of the present invention will be described.

  FIG. 12 and FIG. 13 are diagrams showing the main configuration of the second light source unit 200 in the fourth embodiment of the present invention.

  As in the third embodiment, this embodiment adds a diffusion plate to the configuration of the first embodiment only in the normal mode.

  In the third embodiment, the diffuser plate 1009 is inserted into or removed from the optical path using a mechanism different from the mechanism that rotates the polarizing beam splitter 206. However, in this embodiment, the polarized beam The diffusion plate 1209 is attached to the splitter 206 and rotated together with the polarization beam splitter 206, whereby the diffusion plate 1209 is inserted into or removed from the optical path.

  In the normal mode shown in FIG. 12, the diffuser plate 1209 is disposed on the exit surface of the polarization beam splitter 206. However, when the high brightness mode shown in FIG. 13 is switched, the polarization beam splitter 206 is viewed from the front of the drawing. Therefore, the diffusion plate 1209 moves to a surface that has nothing to do with the optical system. The behavior of the light beam after passing through the polarization beam splitter 206 and the method of changing the reflection surface of the polarization beam splitter 206 are the same as in the first embodiment.

  The effect of adding the diffuser plate 1209 is to create illumination light with higher uniformity, as in the third embodiment. The difference between the third embodiment and this embodiment is that the mechanism for inserting or removing the diffuser plate on the optical path 1209 is integrated with the switching mechanism of the polarization beam splitter 206. Thereby, since the number of movable parts is reduced, the configuration is easy to control and the power consumption can be reduced.

Fifth Embodiment Next, a fifth embodiment of the present invention will be described.

  FIG. 14 and FIG. 15 are diagrams showing the main configuration of the second light source unit 200 in the fifth embodiment of the present invention.

  The basic configuration of this embodiment is the same as that of the first embodiment, but the lens 207 provided between the polarization beam splitter 206 and the illumination unit 300 is movable.

  The lens 207 is moved by a moving mechanism (not shown) in the normal mode in which only B light is irradiated and in the high luminance mode in which G + light and B light are irradiated as shown in FIG. Are placed in different positions. Since the position of the lens 207 is a position corresponding to the spread of the B light that is changed by switching the projection mode, the uniformity is further increased as compared with the first embodiment. The behavior of the light beam after passing through the polarization beam splitter 206 and the method of changing the reflection surface of the polarization beam splitter 206 are the same as in the first embodiment.

  The lens 207 propagates the light beam propagated from the polarization beam splitter 206 to the illumination unit 300 while diverging it. Therefore, by arranging the lens 207 at a position where the degree of divergence is appropriate, the irradiation area of the light incident on the integrator of the illumination unit 300 can be set to a more appropriate range, and illumination light with higher uniformity can be obtained. .

Sixth Embodiment Next, a sixth embodiment of the present invention will be described.

  FIG. 16 and FIG. 17 are diagrams showing the main configuration of the second light source unit 200 in the sixth embodiment of the present invention.

  In this embodiment, the semiconductor laser 1601 emits blue P-polarized laser light. The polarization beam splitter 1606 reflects blue S-polarized light and G light and transmits blue P-polarized light. Further, the arrangement of the phosphor wheel 204 is different from that of the first to fifth embodiments, and the semiconductor laser light transmitted through the polarization beam splitter 1606 is incident on the phosphor wheel 204.

  P-polarized blue laser light is emitted from the semiconductor laser 201. When the projection mode shown in FIG. 16 is the normal mode, the ½λ plate 1609 is disposed so as to be positioned on the incident surface of the polarization beam splitter 206. The semiconductor laser light emitted as P-polarized light is converted into S-polarized light by the 1 / 2λ plate 1609, reflected by the polarizing beam splitter 206, and propagated to the illumination unit 300.

  In the case of the high luminance mode shown in FIG. 17, the polarization beam splitter 1606 rotates 90 degrees clockwise as viewed from the front of the drawing. Since the 1 / 2λ plate 1609 is not related to incident light, the P-polarized blue laser light passes through the polarization beam splitter 1606 and enters the phosphor wheel 204 via the 1 / 4λ plate 208 and the lens 205. The G + light generated by the phosphor wheel 204 and the B light of the reflected semiconductor laser light enter the polarization beam splitter 1606 via the lens 205 and the 1 / 4λ plate 208. At this time, the B light is a 1 / 4λ plate. By passing 208 twice, it becomes S-polarized light, and both G + light and B light are reflected by the polarization beam splitter 206 and propagated to the illumination unit 300.

Seventh Embodiment Next, a seventh embodiment of the present invention will be described.

  FIG. 18 and FIG. 19 are diagrams showing the main configuration of the second light source unit 200 in the seventh embodiment of the present invention.

  In the present embodiment, the polarization beam splitter 1806 reflects blue S-polarized light and G light and transmits blue P-polarized light. Further, the arrangement of the phosphor wheel 204 is configured such that the semiconductor laser light transmitted through the polarization beam splitter 1806 is incident on the phosphor wheel 204 as in the sixth embodiment.

  P-polarized blue laser light is emitted from the semiconductor laser 201. When the projection mode shown in FIG. 18 is the normal mode, the semiconductor laser light emitted as S-polarized light is reflected by the polarizing beam splitter 1806, and at this time, it is located on the exit surface of the reflected light of the polarizing beam splitter 1806. In this way, the 1 / 2λ plate 1809 is arranged, and the semiconductor laser light is converted to P-polarized light by the 1 / 2λ plate 1809 and propagates to the illumination unit 300.

  In the case of the high luminance mode shown in FIG. 19, the polarization beam splitter 1606 rotates 90 degrees clockwise as viewed from the front of the drawing. At this time, the ½λ plate 1809 is positioned on the incident surface of the polarization beam splitter 1606 for the semiconductor laser light, and the semiconductor laser light emitted as S-polarized light is converted into P-polarized blue laser light by the ½λ plate 1809. Then, the light passes through the polarizing beam splitter 1606 and enters the phosphor wheel 204 through the ¼λ plate 208 and the lens 205. The G + light generated by the phosphor wheel 204 and the B light of the reflected semiconductor laser light enter the polarization beam splitter 1606 via the lens 205 and the 1 / 4λ plate 208. At this time, the B light is a 1 / 4λ plate. By passing 208 twice, it becomes S-polarized light, and both G + light and B light are reflected by the polarization beam splitter 206 and propagated to the illumination unit 300.

  In each of the embodiments described above, it is possible to combine the configurations, for example, the configuration in which the semiconductor laser light transmitted through the polarization beam splitter is incident on the phosphor wheel as in the sixth embodiment and the seventh embodiment. Of course, combinations of different diffusion mechanisms as shown in the fifth embodiment may be combined, and the present invention also includes combinations of the embodiments.

DESCRIPTION OF SYMBOLS 100 1st light source part 200 2nd light source part 300 Illumination part 400 Imaging part 500 Projection lens

Claims (6)

A light source that outputs linearly polarized light of a first color;
A polarizing beam splitter;
A phosphor wheel comprising a reflecting surface that reflects incident light to generate reflected light, and a phosphor portion that generates fluorescence of a second color by the incident light;
A quarter-lambda plate provided between the polarizing beam splitter and the phosphor wheel;
A first state in which the polarization beam splitter is rotated to reflect the output light of the light source in a first direction on the reflection surface thereof, and a second state in which the output light of the light source is output toward the phosphor wheel. A polarization beam splitter driving mechanism to be in a state,
The polarization beam splitter outputs the reflected light generated by the phosphor wheel and the second color fluorescence in the first direction in the second state in the first direction. mechanism. In the illumination light switching mechanism according to claim 1,
The polarizing beam splitter reflects the output light of the light source toward the phosphor wheel in the first state, and the reflected light generated in the phosphor wheel in the second state. An illumination light switching mechanism that transmits fluorescence of the second color and outputs the fluorescence in the first direction. In the illumination light switching mechanism according to claim 1,
The polarization beam splitter transmits the output light of the light source toward the phosphor wheel in the first state, and the reflected light generated in the phosphor wheel in the second state. An illumination light switching mechanism that reflects fluorescence of a second color and outputs the reflected light in the first direction. A projector comprising the illumination light switching mechanism according to any one of claims 1 to 3,
A light source unit that generates illumination light of the second color and illumination light of the third color;
A first spatial light modulation element illuminated by illumination light output by the illumination light switching mechanism;
A second spatial light modulation element illuminated by the illumination light of the second color generated by the light source unit;
A third spatial light modulation element illuminated by the illumination light of the third color generated by the light source unit;
A cross dichroic prism that synthesizes each image light obtained by the first to third spatial light modulators;
A projection lens that projects image light synthesized by the cross dichroic prism;
A switching signal indicating that the polarizing beam splitter is set to the first state or the second state and a video signal are input, and the polarizing beam splitter is moved by the polarizing beam splitter driving mechanism according to the switching signal. In the first state or the second state, when the polarization beam splitter is in the first state, the first spatial light modulation element is caused to form an image of the first color indicated in the video signal, and the polarization beam A control unit that causes the first spatial light modulator to form a first color image and a second color image indicated by the video signal when the splitter is in the second state; Projector. The projector according to claim 4, wherein
The control unit is configured such that when the polarization beam splitter is in the second state, the output light intensity of the light source when the first color light is output is higher than that in the first state. A projector. A light source that outputs linearly polarized light of a first color;
A polarizing beam splitter;
A phosphor wheel comprising a reflecting surface that reflects incident light to generate reflected light, and a phosphor portion that generates fluorescence of a second color by the incident light;
An illumination light switching method performed by an illumination light output mechanism comprising a quarter-λ plate provided between the polarizing beam splitter and the phosphor wheel,
A polarization beam splitter driving mechanism rotates the polarization beam splitter so that the reflection surface reflects the output light of the light source in a first direction and the output light of the light source to the phosphor wheel. One of the second states to be output,
An illumination light switching method in which the polarized beam splitter outputs the reflected light and the second color fluorescence generated in the phosphor wheel in the first direction in the second state.

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