JP2012018762A

JP2012018762A - Light source device and projector

Info

Publication number: JP2012018762A
Application number: JP2010153672A
Authority: JP
Inventors: Akira Egawa; Kaname Hase; 明江川; 要長谷
Original assignee: Seiko Epson Corp; セイコーエプソン株式会社
Priority date: 2010-07-06
Filing date: 2010-07-06
Publication date: 2012-01-26
Anticipated expiration: 2030-07-06
Also published as: JP5527059B2

Abstract

PROBLEM TO BE SOLVED: To provide a light source device which can improve utilization efficiency of light through restraint of dust adhesion on a surface of a phosphor layer.SOLUTION: The light source device 10 includes a wavelength conversion member 1 including a substrate which can rotate around a given rotating axis and a phosphor layer containing a phosphor and fitted to the substrate, a light source 11, condensing optical systems 12, 13 making excitation light emitted from the light source to be irradiated to be condensed to the phosphor layer, and a casing 16 with a sealed space 20 formed for housing the wavelength conversion member and blocking from outside.

Description

The present invention relates to a light source device and a projector, and more particularly to a technology of a light source device using fluorescence obtained by exciting a phosphor with laser light.

In recent years, lasers have attracted attention as a light source with a wide color gamut and high efficiency for improving the performance of projectors. For example, in Patent Document 1 and Patent Document 2, red light is emitted from a blue light laser and a color wheel that generates green light and red light as fluorescence by exciting the phosphor contained in the phosphor layer with laser light. Techniques for obtaining blue and green illumination light have been proposed.

JP 2009-277516 A JP 2010-86815 A

However, if dust adheres directly to the surface of the phosphor layer of the color wheel, laser light incident on the phosphor layer or light emitted from the phosphor layer is absorbed or scattered by the dust. There is a problem that will decrease.

SUMMARY An advantage of some aspects of the invention is that it solves at least a part of the above-described problems and can provide a light source device capable of improving light use efficiency and a projector using the light source device.

In order to solve the above-described problems and achieve the object, the present invention includes a substrate that is rotatable about a predetermined rotation axis, and a phosphor layer that includes the phosphor and is provided on the substrate. A wavelength conversion member, a light source, a condensing optical system for irradiating the phosphor layer with the excitation light emitted from the light source, and a sealed space for accommodating the wavelength conversion member and blocking the outside are formed inside And a casing.

Since the wavelength conversion member is accommodated in a sealed space that is blocked from the outside, it is possible to prevent dust from adhering directly to the phosphor layer. Since dust can be prevented from directly adhering to the phosphor layer, it is possible to suppress a decrease in the utilization efficiency of excitation light.

Moreover, as a preferable aspect of the present invention, it is desirable that a space for accommodating the light source is formed separately from the sealed space for accommodating the wavelength conversion member. Since the light source and the wavelength conversion member are accommodated in separate spaces, the heat generated on one side is hardly transmitted to the other side. Thereby, for example, the cooling efficiency of the wavelength conversion member is reduced due to heat generated in the light source and the light conversion efficiency is reduced, or the light generation efficiency is reduced due to heat generated in the wavelength conversion member. Can be suppressed.

Moreover, as a preferable aspect of the present invention, it is desirable that the partition that separates the sealed space that houses the wavelength conversion member and the space that houses the light source includes a condensing optical system. Since the partition includes the condensing optical system, the function of condensing light on the partition can be exhibited. Therefore, the material can be reduced and the weight can be reduced as compared with the case where the partition walls are provided only for separating the spaces. In order to make the excitation light emitted from the light source enter the phosphor wheel, the partition that separates the space that houses the light source and the sealed space that houses the wavelength conversion member needs to be made of a translucent member. is there. On the other hand, since the condensing optical system transmits light, it can be used as the partition wall.

Moreover, as a preferable aspect of the present invention, it is desirable to further include a drive unit that rotates the substrate, and the drive unit is housed in a sealed space formed in the casing. Since the drive unit is housed in a sealed space that is blocked from the outside, noise generated by driving the drive unit is less likely to leak to the outside. Thereby, the quietness at the time of driving of the light source device can be improved.

Moreover, as a preferable aspect of the present invention, it is desirable that at least a part of the casing is made of a metal material. Since at least a part of the casing is made of a metal material having high thermal conductivity, the heat dissipation efficiency from the casing can be improved. Therefore, the heat generated by the wavelength conversion member and the light source can be efficiently radiated to the outside through the casing.

Moreover, as a preferable aspect of the present invention, it is desirable that heat dissipating fins be formed on the outer peripheral surface of the casing. Since the fins are formed on the outer peripheral surface of the casing, the heat dissipation area of the casing is increased, so that the heat dissipation efficiency from the casing can be further improved. Therefore, the heat generated by the wavelength conversion member and the light source can be radiated to the outside more efficiently through the casing.

Moreover, as a preferable aspect of the present invention, it is desirable that the wavelength conversion member is formed with a fluidized portion that causes the air in the sealed space to flow by the rotation of the substrate. By rotating the substrate, the air around the wavelength conversion member, that is, the air in the sealed space in which the wavelength conversion member is accommodated can be flowed, so that the heat dissipation efficiency of the wavelength conversion member can be improved.

A projector according to another aspect of the invention includes the light source device and a spatial light modulation device that modulates light emitted from the light source device in accordance with an image signal. The projector includes the light source device that suppresses the dust from adhering to the phosphor layer and suppresses the decrease in the use efficiency of the excitation light. Therefore, it is possible to improve the reliability and obtain a high-quality image.

FIG. 1 is a diagram illustrating a schematic configuration of a light source device according to Embodiment 1 of the present invention. FIG. 2 is an exploded perspective view of the light source device shown in FIG. FIG. 3 is a front view of the phosphor wheel. FIG. 4 is a cross-sectional view of the phosphor wheel. FIG. 5 is an exploded perspective view of the light source device according to the first modification of the first embodiment. FIG. 6 is an external perspective view of the phosphor wheel provided in the light source device according to the second modification of the first embodiment. FIG. 7 is a diagram illustrating a schematic configuration of the projector according to the second embodiment of the invention.

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram illustrating a schematic configuration of a light source device according to Embodiment 1 of the present invention. FIG. 2 is an exploded perspective view of the light source device shown in FIG. The light source device 10 includes a light source 11, a collimator lens 12, a condenser lens 13, a phosphor wheel (wavelength conversion member) 1, a pickup lens 14, a drive unit 15, and a casing 16.

The light source 11 emits light toward the collimating lens 12. The light source 11 is configured by arranging a plurality of semiconductor lasers that emit laser light, for example. Note that the light source 11 may be configured by arranging a plurality of LEDs.

The collimating lens 12 and the condensing lens 13 function as a condensing optical system that irradiates the phosphor layer 3 provided on the phosphor wheel 1 so that the laser light emitted from the light source 11 is condensed. The collimator lens 12 collimates the laser light emitted from the light source 11 and emits it toward the condenser lens 13. The condensing lens 13 condenses the laser light emitted from the collimating lens 12 on the phosphor layer 3 of the phosphor wheel 1. The condensing lens 13 condenses the laser light toward a small part (for example, about 1 mm ² ) of the phosphor layer 3.

FIG. 3 is a front view of the phosphor wheel 1. FIG. 4 is a cross-sectional view of the phosphor wheel 1. The phosphor wheel 1 has a substrate 2 and a phosphor layer 3 containing a phosphor (not shown). The substrate 2 has a circular thin plate shape. The substrate 2 is made of a transparent member and has a property of transmitting light. For the substrate 2, for example, glass, white plate, quartz, crystal, sapphire, YAG (Yttrium Aluminum Garnet), or the like is used.

A circular opening 2 a is formed at the center of the substrate 2. A drive shaft of the drive unit 15 for rotating the phosphor wheel 1 is inserted into the opening 2a. The drive unit 15 is, for example, a motor. As a result, the substrate 2 can be rotated about the rotation axis 5 passing through the center of the substrate 2. The driving unit 15 is held by a driving unit holding unit 21 provided in the casing 16.

The phosphor layer 3 is applied to the surface of the substrate 2 in an annular shape having the same center as the center of the substrate 2. The phosphor layer 3 is formed by, for example, applying a mixture of a phosphor and a binder (resin material) to the surface of the substrate 2. Part of the laser light irradiated on the phosphor layer 3 is absorbed by the phosphor. The phosphor that has absorbed the laser light is excited to generate fluorescence. In this embodiment, the phosphor wheel 1 functions as a wavelength conversion member because a phosphor that generates yellow fluorescence by absorbing blue laser light is used.

Here, when light is emitted from the light source device 10, the laser light is condensed and irradiated on a part of the phosphor layer 3 while rotating the phosphor wheel 1 about the rotation shaft 5. Therefore, the region irradiated with the laser light always moves on the phosphor layer 3, and it is possible to prevent the phosphor layer 3 from being locally heated.

Although not shown, a dichroic mirror is provided between the substrate 2 and the phosphor layer 3 to transmit the laser light incident from the substrate 2 side, but reflect the light scattered by the phosphor layer 3. Yes. By providing a dichroic mirror between the substrate 2 and the phosphor layer 3, the light traveling toward the substrate 2 out of the laser light scattered by the phosphor layer 3 is reflected to the pickup lens 14 side described later. Therefore, the light utilization efficiency can be improved.

The pickup lens 14 condenses the light emitted from the phosphor layer 3. The laser light incident on the phosphor wheel 1 is scattered when it passes through the phosphor layer 3 and travels in various directions as lumbar radiation. Therefore, the laser light and fluorescence emitted from the phosphor wheel 1 are collected by the pickup lens 14 and used as illumination light, thereby improving the light utilization efficiency.

The casing 16 is a case member that accommodates the light source 11, the collimating lens 12, the condenser lens 13, the phosphor wheel (wavelength conversion member) 1, and the drive unit 15. As shown in FIG. 2, the casing 16 is divided into an upper case 17 and a lower case 18. The casing 16 is configured by combining an upper case 17 and a lower case 18.

By combining the upper case 17 and the lower case 18, a light source accommodating portion 19 that accommodates the light source 11 and a phosphor wheel accommodating portion 20 that accommodates the phosphor wheel 1 are formed inside the casing 16. The phosphor wheel housing portion 20 is a sealed space that is blocked from the external space. Moreover, the light source housing part 19 and the phosphor wheel housing part 20 are formed as spaces independent from each other.

The light source 11 is accommodated in the light source accommodating portion 19. The phosphor wheel housing unit 20 houses the phosphor wheel 1 and also houses the driving unit 15, the driving unit holding unit 21, the condenser lens 13, and the pickup lens 14.

A partition that separates the light source housing 19 and the phosphor wheel housing 20 includes the collimating lens 12. That is, in a state where the collimating lens 12 is not disposed, the light source housing portion 19 and the phosphor wheel housing portion 20 are in communication with each other. By arranging 12, the accommodating portions 19 and 20 become spaces independent of each other.

Here, in order for the laser light emitted from the light source 11 to enter the phosphor wheel 1, the partition wall that separates the light source housing portion 19 and the phosphor wheel housing portion 20 needs to be made of a translucent member. is there. Since the collimating lens 12 used as a partition wall in the first embodiment transmits light, it can be used as a partition wall that separates the light source housing portion 19 and the phosphor wheel housing portion 20.

Since the partition which separates the light source accommodating part 19 and the fluorescent substance wheel accommodating part 20 is comprised including the collimating lens 12, the function as a lens can also be exhibited in the partition part. Therefore, the material can be reduced and the weight can be reduced as compared with the case where the partition walls are provided only for separating the accommodating portions 19 and 20.

In addition, you may comprise the partition which separates the light source accommodating part 19 and the fluorescent substance wheel accommodating part 20 including the condensing lens 13. FIG. In this case, the collimating lens 12 is housed on the light source housing portion 19 side. Since the condenser lens 13 also transmits light, it can be used as a partition wall that separates the light source housing portion 19 and the phosphor wheel housing portion 20.

Moreover, the partition which separates the light source accommodating part 19 and the phosphor wheel accommodating part 20 is made of a translucent member such as a glass plate or a plastic plate without using a condensing optical system such as the collimating lens 12 and the condensing lens 13. You may comprise separately.

In the casing 16, a surface that is an emission direction of light from the light source device 10, that is, a surface that is irradiated with light emitted from the pickup lens 14 (emission surface 16 a) is formed of a translucent member. The emission surface 16a is made of, for example, a glass plate or a plastic plate.

The exit surface 16a may function as a lens. For example, the emission surface 16 a may be configured including the pickup lens 14. By providing the pickup lens 14 so as to be embedded in the light transmitting portion of the emission surface 16a, the above-described glass plate, plastic plate, or the like becomes unnecessary, so that the number of parts can be reduced and the space can be saved. Moreover, parts other than the injection surface 16a in the casing 16 are made of a material having high thermal conductivity, for example, a metal material.

As described above, since the phosphor wheel 1 is housed in the phosphor wheel housing portion 20 that is blocked from the outside, it is possible to prevent dust from directly adhering to the surface of the phosphor layer 3. As described above, since the laser light is condensed toward a very small area of the phosphor layer 3, if dust adheres directly to the phosphor layer 3, it is easy to prevent the light from traveling, and the light use efficiency is reduced. It becomes easy to do. On the other hand, in the present embodiment, it is possible to prevent dust from directly adhering to the region irradiated with laser light on the surface of the phosphor layer 3, so that it is possible to suppress a decrease in light utilization efficiency.

In addition, a part of the energy of the light transmitted through the phosphor layer 3 is converted into heat, and since the irradiation region is a very small region, the light irradiation region of the phosphor layer 3 has a very high temperature. Prone. Therefore, it is possible to suppress the occurrence of problems due to the prevention of dust from adhering to the surface of the phosphor layer 3 that tends to become high temperature, for example, the decrease in light utilization efficiency due to the scorching of the adhering dust.

Moreover, since the light source 11 and the phosphor wheel 1 are accommodated in separate spaces, the heat generated on one side is hardly transmitted to the other side. Thereby, for example, the cooling efficiency of the phosphor wheel 1 is reduced by the heat generated in the light source 11 and the light conversion efficiency is reduced, or the cooling efficiency of the light source 11 is reduced by the heat generated in the phosphor wheel 1. It can suppress that luminous efficiency falls.

Moreover, since the drive part 15 is accommodated in the inside of the fluorescent substance wheel accommodating part 20 which is the sealed space blocked | interrupted from the exterior, the noise which generate | occur | produces by the drive of the drive part 15 becomes difficult to leak outside. Thereby, the quietness at the time of driving the light source device 10 can be improved.

Moreover, since a part of casing 16 is comprised with the metal material with high heat conductivity, the thermal radiation efficiency from the casing 16 can be improved, and the heat | fever which generate | occur | produced in the fluorescent substance wheel 1 or the light source 11 is made into the casing 16. The heat can be efficiently radiated to the outside via

In the first embodiment, the light source accommodating portion 19 is formed inside the casing 16 to accommodate the light source 11. However, the present invention is not limited to this, and the light source 11 is not formed without forming the light source accommodating portion 19. May be provided outside the casing 16. Further, if only the phosphor wheel 1 is accommodated in the phosphor wheel accommodating portion 20, dust can be prevented from adhering to the surface of the phosphor layer 3, so that the condensing lens 13, the pickup lens 14, and the drive The part 15 and the like may be provided outside the phosphor wheel housing part 20. Further, although the amount of heat generated in the phosphor wheel housing portion 20 increases, the light source 11 may be housed in the phosphor wheel housing portion 20.

[Modification 1]
FIG. 5 is an exploded perspective view of the light source device 10 according to the first modification of the first embodiment. As shown in FIG. 5, in the first modification, fins 16 b are formed on the outer peripheral surface of the casing 16, particularly on a portion made of metal. Since the fins 16b are formed on the outer peripheral surface of the casing 16, the heat dissipation area of the casing 16 is increased, so that the heat dissipation efficiency from the casing 16 can be further improved. Therefore, heat generated by the phosphor wheel 1 and the light source 11 can be efficiently radiated to the outside through the casing 16.

[Modification 2]
FIG. 6 is an external perspective view of the phosphor wheel 1 included in the light source device according to the second modification of the first embodiment. In the second modification, a plurality of blade portions (fluid portions) 22 are formed so as to protrude from the surface of the substrate 2 opposite to the surface on which the phosphor layer 3 is applied. By rotating the phosphor wheel 1, the plurality of blade portions 22 function as a sirocco fan that causes air to flow as a whole.

Therefore, by rotating the phosphor wheel 1, the air around the phosphor wheel 1, that is, the air inside the phosphor wheel housing portion 20 can flow, and the heat dissipation efficiency of the phosphor wheel 1 is further improved. Can be made.

In addition, the blade | wing part 22 does not need to function as a sirocco fan, and the protrusion formed so that it might protrude only from a board | substrate may be sufficient. Even if it is such a protrusion, if the phosphor wheel 1 is rotated, the surrounding air can be flowed, which can contribute to the improvement of the cooling efficiency of the phosphor wheel 1.

FIG. 7 is a diagram illustrating a schematic configuration of the projector according to the second embodiment of the invention. The projector 60 according to the second embodiment includes the light source device 10 according to the first embodiment. Laser light emitted from the light source 11 enters the phosphor wheel 1 as excitation light. The laser light incident on the phosphor wheel 1 excites a phosphor layer (not shown), and fluorescence is emitted from the phosphor. Illumination light including red (R) light, green (G) light, and blue (B) light is emitted from the light source device 10 by the light transmitted through the phosphor layer and the excited fluorescence. For example, if a blue laser is used as a light source and a phosphor layer containing a phosphor emitting red and green bands is used as a phosphor, the three primary colors of light can be reproduced with a small configuration.

The homogenizing optical system 64 is an optical system that homogenizes the intensity distribution of light incident from the light source device 10 and includes, for example, a rod integrator. The dichroic mirror 65 transmits B light out of the light from the uniformizing optical system 64 and reflects R light and G light. The dichroic mirror 66 transmits R light and reflects G light. The dichroic mirrors 65 and 66 function as a color separation optical system that separates the light from the light source device 10 for each color.

The R light transmitted through the dichroic mirror 66 is reflected by the reflection mirrors 67 and 68 and then enters the R light spatial light modulator 70R. The spatial light modulation device 70R modulates the R light according to the image signal. The G light reflected by the dichroic mirror 66 is incident on the spatial light modulator 70G for G light. The spatial light modulation device 70G modulates the G light according to the image signal. The B light transmitted through the dichroic mirror 65 is reflected by the reflection mirror 69 and then enters the B light spatial light modulator 70B. The spatial light modulators 70R, 70G, and 70B are, for example, transmissive liquid crystal display devices.

A cross dichroic prism 71, which is a color synthesis optical system, synthesizes the respective color lights modulated by the spatial light modulation devices 70R, 70G, and 70B. The projection optical system 72 projects each color light synthesized by the cross dichroic prism 71 onto the screen 73.

Since the projector 60 includes the light source device 10 that suppresses the dust from adhering to the surface of the phosphor layer and suppresses the decrease in light use efficiency, it is possible to improve the reliability and obtain a high-quality image. Become. The projector 60 may be configured to include the light source device 10 according to the first modification or the second modification described in the first embodiment.

The projector 60 is not limited to the case where a transmissive liquid crystal display device is used as the spatial light modulation device. As the spatial light modulator, a reflective liquid crystal display (Liquid Crystal On Silicon; LCOS), DMD (Digital Micromirror Device), GLV (Grating Light Valve), or the like may be used.

As described above, the light source device according to the present invention is suitable for use in a projector.

DESCRIPTION OF SYMBOLS 1 Phosphor wheel (wavelength conversion member), 2 board | substrate, 2a opening, 3 phosphor layer, 5 rotating shaft, 10 light source device, 11 light source, 12 collimating lens (condensing optical system), 13 condensing lens (condensing optics) System), 14 pickup lens, 15 drive unit, 16 casing, 16a emission surface, 16b fin, 17 upper case, 18 lower case, 19 light source storage unit, 20 phosphor wheel storage unit (sealed space), 21 drive unit holding unit , 22 blade part (flow part), 60 projector, 64 homogenization optical system, 65 dichroic mirror, 66 dichroic mirror, 67 reflection mirror, 69 reflection mirror, 70R spatial light modulation device, 70G spatial light modulation device, 70B spatial light modulation Equipment, 71 Cross dichroic prism, 72 Projection optical system, 73 Screen

Claims

A wavelength conversion member having a substrate that is rotatable around a predetermined rotation axis, and a phosphor layer that includes the phosphor and is provided on the substrate;
A light source;
A condensing optical system for irradiating the phosphor layer with the excitation light emitted from the light source;
A light source device, comprising: a casing in which a sealed space for accommodating the wavelength conversion member and blocking from the outside is formed.
The light source device according to claim 1, wherein a space for accommodating the light source is formed separately from a sealed space for accommodating the wavelength conversion member.
The light source device according to claim 2, wherein a partition that separates a sealed space that houses the wavelength conversion member and a space that houses the light source includes the condensing optical system.
A drive unit for rotating the substrate;
The light source device according to claim 1, wherein the driving unit is housed in a sealed space formed in the casing.
The light source device according to claim 1, wherein at least a part of the casing is made of a metal material.
The light source device according to any one of claims 1 to 5, wherein a fin for heat dissipation is formed on an outer peripheral surface of the casing.
7. The light source device according to claim 1, wherein the wavelength conversion member is formed with a flow portion that causes the air in the sealed space to flow by rotation of the substrate.
The light source device according to any one of claims 1 to 7,
A projector comprising: a spatial light modulator that modulates light emitted from the light source device according to an image signal.