CN107515510B

CN107515510B - Light source device and projection display device

Info

Publication number: CN107515510B
Application number: CN201710600214.6A
Authority: CN
Inventors: 山影明广; 梅雨非
Original assignee: Light And Technology Co Ltd
Current assignee: Sonoc Beijing Technology Co ltd
Priority date: 2017-03-23
Filing date: 2017-07-21
Publication date: 2020-01-10
Anticipated expiration: 2037-07-21
Also published as: CN107515510A; JP2018159837A

Abstract

The present invention relates to a light source device and a projection display device. A phosphor is provided on a slope inclined with respect to the rotation axis of the rotating body, and the optical axis of the condensing lens group intersects the rotation axis of the rotating body at an angle of 10 degrees or more and 80 degrees or less. In order to excite the phosphor, the first excitation light source and the second excitation light source are arranged on opposite sides with respect to the rotation axis of the rotating body, and the mirror surface of the synthetic dichroic mirror is arranged in a direction along the extension direction of the rotation axis. Since the difference in optical path length from the phosphor to the light combining mirror is greatly reduced for different emission colors, it is possible to output high-quality illumination light in which the angle characteristics and intensity distributions of the respective color components are uniform without providing an expensive adjustment optical system.

Description

Light source device and projection display device

Technical Field

The present invention relates to a light source device including a semiconductor laser and a phosphor, and a projection display device using the light source device.

Background

In recent years, semiconductor lasers have been developed which output light having a short wavelength with high emission efficiency. It has been proposed to excite a phosphor with the output light of such a semiconductor laser and use the wavelength-converted light as a light source of a projection display device.

Although the phosphor can be fixed at a certain position and irradiated with excitation light, if the excitation light is always continuously irradiated to the same point of the phosphor, the temperature may be locally increased, the light emission efficiency may be decreased, and further, the material may be deteriorated. Therefore, a light source is often used in which a fluorescent material is provided on the main surface of a rotating disk in advance so that excitation light does not irradiate the fluorescent material at the same point.

For example, patent document 1 describes a projection display device in which the output light of a semiconductor laser is irradiated to a rotating fluorescent plate using a condenser lens group, and the fluorescent light emitted from the fluorescent plate is selected by a dichroic mirror and guided to a liquid crystal light modulation device.

Further, in the recent development of information-oriented society, color display is often required for projection display devices, and for example, patent documents 2 and 3 disclose a light source capable of emitting light of a plurality of colors simultaneously by disposing phosphors having different emission colors concentrically on a single rotating body, and a projection display device using the light source.

Patent document 1: japanese patent laid-open publication No. 2016-146293

Patent document 2: japanese patent laid-open publication No. 2013-47777

Patent document 3: japanese laid-open patent publication No. 2012-142222

In the projection display devices disclosed in patent documents 2 and 3, phosphors provided on a rotating body and having different emission colors are irradiated with excitation light, and fluorescence of different wavelengths emitted from the respective phosphors is condensed and synthesized to be irradiated to a light modulation device.

That is, in the conventional apparatus shown in fig. 12, for example, the red phosphor 112 and the green phosphor 113 are formed in two annular patterns having different radii on the main surface of the rotating plate 110 rotated by the motor 111, with the rotation axis of the rotating plate as the center. Further, an excitation light source assembly 114 is provided for the red phosphor 112, and an excitation light source assembly 115 is provided for the green phosphor 113. Each excitation light source assembly has: a laser light source that emits light of an excitation wavelength; and an optical lens group for shaping the excitation light. Between excitation light source assembly 114 and red phosphor 112, dichroic mirror 116 and condenser lens group 118 are arranged. Further, between the excitation light source assembly 115 and the green phosphor 113, a dichroic mirror 117 and a condenser lens group 119 are arranged.

The condenser lens group 118 and the condenser lens group 119 are lens groups that condense excitation light to be applied to a phosphor and condense fluorescence to be transmitted to a dichroic mirror.

The dichroic mirror 117 is a mirror that transmits the excitation light from the excitation light source unit 115 in the direction of the green phosphor 113 and reflects the fluorescence from the green phosphor 113. The dichroic mirror 116 is a reflecting mirror that transmits the excitation light from the excitation light source unit 114 in the direction of the red fluorescent material 112, reflects the fluorescent light from the red fluorescent material 112, and transmits the fluorescent light from the green fluorescent material 113 that has reached through the dichroic mirror 117. In other words, the dichroic mirror 116 can also be said to function as a light combining mirror that combines the red fluorescence and the green fluorescence.

In such a light source, if the length of the optical path from red phosphor 112 to dichroic mirror 116 (light-combining mirror) via condenser lens group 118 is compared with the length of the optical path from green phosphor 113 to dichroic mirror 116 (light-combining mirror) via condenser lens group 119, there is a large difference substantially equal to the diameter of the phosphor annular pattern. Therefore, there may be a case where a significant difference occurs in the angular characteristic and the intensity distribution between the red light component and the green light component included in the combined light.

As described above, if the combined light having a difference in angular characteristics and intensity distribution for each color component is used as the illumination light of the projection display device, the reflection combining characteristics of the illumination optical system and the telecentricity of the projection lens are affected differently depending on the light color component, and thus, unevenness in depth of the screen color is likely to occur in the display image. Therefore, if the color shading is to be suppressed, the light that can be used by the projection lens needs to be limited, which causes a problem of a decrease in light use efficiency.

On the other hand, if the angular characteristics and intensity distributions of the red light component and the green light component are to be adjusted on the light source side, an adjustment optical system for adjusting the influence of the difference in optical path length needs to be provided between the dichroic mirror 117 and the dichroic mirror (light-combining mirror) 116, for example, but there are problems that it is difficult to arrange in reality and the cost of the adjustment lens is high.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object of the present invention is to provide a light source in which a difference in optical path length between light of different colors from a fluorescent material and reaching a light combining mirror through a condensing lens group is significantly reduced as compared with the conventional light source. That is, an object of the present invention is to provide a light source capable of outputting high-quality illumination light in which the angular characteristics and intensity distributions of the respective color components are uniform without providing an expensive adjustment optical system by greatly reducing the difference in optical path length for each color. It is another object of the present invention to provide a high-quality projection display device including such a light source device at low cost.

The present invention is a light source device, including: a rotating body which can rotate around a rotating shaft and at least one part of the side part of which is coated with a fluorescent body; a first excitation light source for exciting the phosphor; a second excitation light source for exciting the phosphor; a first dichroic mirror that transmits excitation light from the first excitation light source and reflects at least a part of fluorescence from the phosphor; a second dichroic mirror that transmits excitation light from the second excitation light source and reflects at least a part of fluorescence from the phosphor; a first condenser lens group disposed between the first dichroic mirror and the phosphor; a second condenser lens group disposed between the second dichroic mirror and the phosphor; and a light combining mirror that reflects the fluorescent light from the fluorescent material reflected by the first dichroic mirror and transmits the fluorescent light from the fluorescent material reflected by the second dichroic mirror, wherein the first excitation light source and the second excitation light source are arranged on opposite sides with respect to a rotation axis of the rotating body, and a mirror surface of the light combining mirror is arranged along the rotation axis on an extension line of the rotation axis of the rotating body.

Further, the present invention is a projection display device including: the light source device described above; a light modulation device; and a projection lens.

According to the present invention, it is possible to provide a light source in which the difference in optical path length from the fluorescent material to the light combining mirror for light of different colors is significantly reduced as compared with the conventional one. That is, it is possible to provide a light source capable of outputting high-quality illumination light in which the angular characteristics and intensity distribution of each color component are uniform without providing an expensive adjustment optical system by greatly reducing the difference in optical path length for each color. Further, a projection display device having such a light source device and a high-quality image can be provided at low cost.

Drawings

Fig. 1 is a diagram illustrating a structure of a light source device according to a first embodiment.

Fig. 2 is a diagram showing a structure of a light source device of a second embodiment.

Fig. 3 is a diagram showing a configuration of a projection display device of a third embodiment.

Fig. 4 is a diagram illustrating a structure of a light source device according to a fourth embodiment.

Fig. 5 (a) is a plan view of the rotating body according to the fourth embodiment, and fig. 5 (b) is a timing chart showing the driving timing of each part of the light source according to the fourth embodiment.

Fig. 6 is a diagram illustrating a configuration of a projection display device of a fifth embodiment.

Fig. 7 is a diagram showing a structure of a light source device according to a sixth embodiment.

Fig. 8 is a diagram illustrating a structure of a light source device according to a seventh embodiment.

Fig. 9 is a diagram illustrating a structure of a light source device according to an eighth embodiment.

Fig. 10 is a diagram illustrating a structure of a light source device of a ninth embodiment.

Fig. 11 (a) is a plan view of the rotating body according to the tenth embodiment, and fig. 11 (b) is a timing chart showing the driving timing of each part of the light source according to the tenth embodiment.

Fig. 12 is a diagram showing a configuration of a conventional light source device.

Description of the symbols

1 … light source device

10 … rotator

11 … motor

12 … Red phosphor

13 … Green phosphor

14 … excitation light source assembly

15 … excitation light source assembly

16 … dichroic mirror

17 … dichroic mirror

18 … condenser lens group

19 … condenser lens group

20 … light-combining mirror

21 … light source device

22 … blue light source assembly

310 … relay lens

320 … first lens array

330 … second lens array

340 … polarization conversion device

350 … superposition lens

360 … dichroic mirror

361 … dichroic mirror

362. 363, 364 … mirror

370 … crossed dichroic prism

381 … lens for red (R)

382 … transmissive liquid crystal panel for red (R)

383 … Green (G) lens

Transmissive liquid crystal panel for 384 … green (G)

385 … blue (B) lens

386 … transmissive liquid crystal panel for blue (B)

390 … projection lens

391 … projection screen

401 … light source device

40 … rotary body

41 … motor

42 … fluorescent body

42R … Red phosphor

42G … Green phosphor

44 … excitation light source assembly

45 … excitation light source assembly

50 … light-combining mirror

51 … blue light source module

52 … fluorescent body

610 … relay lens

620 … relay lens

640 … optical channel

650 … illuminating lens group

660 … light modulation device

671 … prism

672 … prism

680 … projection lens

690 … projection screen

Optical axes of EA1, EA2, EA3, EA4 … condenser lens group

Rotation axis of RA … rotary body

Detailed Description

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

[ first embodiment ]

A light source device according to a first embodiment of the present invention will be described with reference to fig. 1.

In the figure, 1 is a light source device, 10 is a rotating body, 11 is a motor, 12 is a red phosphor, 13 is a green phosphor, 14 and 15 are excitation light source components, 16 is a first dichroic mirror, 17 is a second dichroic mirror, 18 and 19 are condenser lens groups, and 20 is a light combining mirror.

In the present apparatus, red phosphor 12 and green phosphor 13 having different emission wavelength characteristics are formed in two annular patterns having different radii around rotation axis RA of rotating body 10 on the inclined surface of the side portion of rotating body 10 that can be rotated by motor 11. In other words, the red phosphor is provided on the circumference of a first circle centered on the rotation axis, and the green phosphor is provided on the circumference of a second circle having a radius different from that of the first circle. In order to prevent the phosphor from overheating, a metal having high thermal conductivity is suitably used as the base material of the rotating body 10, and a concave portion for cooling is provided.

Further, an excitation light source unit 14 is provided for the red phosphor 12, and an excitation light source unit 15 is provided for the green phosphor 13. Each excitation light source assembly has: a laser light source that emits light having a wavelength capable of exciting the phosphor; and an optical lens group for shaping the excitation light. For example, a module in which a plurality of blue laser light sources arranged in an array and a plurality of collimator lenses arranged corresponding to the respective blue laser light sources are integrated is suitably used.

Each module includes a light emitting device array in which blue laser light sources are arranged in a matrix of 2 × 4. However, the size of the matrix arrangement included in one module is not limited to this example, and may be a larger-size matrix arrangement or a matrix arrangement in which the number of vertical and horizontal directions is the same. The blue laser light source used in the light source module is, for example, a semiconductor laser that emits light having a wavelength of 445 nm. The light output from each laser light source is emitted from the excitation light source assembly as substantially parallel light rays by the action of the lens group. The excitation light source assembly 14 and the excitation light source assembly 15 may have the same structure.

Between excitation light source assembly 14 and red phosphor 12, dichroic mirror 16 and condenser lens group 18 are arranged. Further, between the excitation light source assembly 15 and the green phosphor 13, a dichroic mirror 17 and a condenser lens group 19 are arranged.

In addition, not limited to this embodiment, in the following description of all embodiments, a dichroic mirror disposed between an excitation light source assembly and a phosphor has a high transmittance for excitation light of a wavelength suitable for exciting the phosphor, and has a high reflectance for light in a wavelength region desired to be output from the light source device among fluorescence emitted from the phosphor. In other words, the dichroic mirror disposed between the excitation light source assembly and the phosphor reflects at least a part of the fluorescence emitted by the phosphor, but not necessarily all of it.

Further, the wavelength characteristics between dichroic mirrors corresponding to different excitation light source components are set to be different. For example, a dichroic mirror corresponding to one excitation light source unit has a characteristic of transmitting green light and reflecting red light, whereas a dichroic mirror corresponding to the other excitation light source unit has a characteristic of reflecting green light. Of course, the situation where the dichroic mirrors differ in wavelength characteristics is not limited to this example, and may be appropriately changed.

Dichroic mirror 16 transmits the excitation light from excitation light source unit 14 in the direction of red phosphor 12, and reflects the fluorescence (red light) from red phosphor 12. Further, the dichroic mirror 17 transmits the excitation light from the excitation light source unit 15 in the direction of the green phosphor 13, and reflects the fluorescence (green light) from the green phosphor 13. The mirror surfaces of the dichroic mirror 16 and the dichroic mirror 17 are arranged parallel to the rotation axis RA of the rotating body.

The condenser lens group 18 is a lens group that condenses excitation light from the excitation light source assembly 14 to irradiate the red phosphor 12 and condenses fluorescence emitted from the red phosphor 12 to transmit the collected fluorescence to the dichroic mirror 16. Similarly, the condenser lens group 19 is a lens group that condenses excitation light from the excitation light source assembly 15 to irradiate the green phosphor 13 and condenses and transmits fluorescence emitted from the green phosphor 13 to the dichroic mirror 17. The condenser lens group 18 and the condenser lens group 19 are formed of two lenses in the example of fig. 1, but the number of lenses is not limited thereto. The condenser lens group 18 and the condenser lens group 19 may have the same structure.

The light combining mirror 20 is a dichroic mirror that reflects red light and transmits green light. The mirror surface of the light combining mirror 20 is arranged in a direction along the rotation axis RA direction on the extension line of the rotation axis RA of the rotating body 10. When an angle formed by the mirror surface of the light combining mirror 20 with respect to the optical axis of the combined light described later is θ 3, θ 3 is set to 45 degrees.

In the present embodiment, the excitation light is condensed by the condenser lens group and irradiated to the phosphor provided on the inclined surface of the side portion of the rotating body 10. In the figure, EA1 denotes an optical axis (including an extension) of the condenser lens group 18, EA2 denotes an optical axis (including an extension) of the condenser lens group 19, and RA denotes a rotation axis of the rotary body 10. In the present embodiment, the optical axis EA1 is orthogonal to the optical axis EA 2.

In the present embodiment, an angle θ 1 formed by the optical axis EA1 of the condenser lens group 18 and the rotation axis RA of the rotating body 10 is set to 10 degrees or more and 80 degrees or less. An angle θ 2 formed by the optical axis EA2 of the condenser lens group 19 and the rotation axis RA of the rotating body 10 is set to 10 degrees or more and 80 degrees or less. In addition, θ 1 and θ 2 are arranged to be the same except for manufacturing errors, and are set to 45 degrees in the present embodiment. In this way, by arranging the optical axis of the condenser lens group and the rotation axis at an angle other than parallel, even if the thrust of the motor in the axial direction is fluctuated, the risk of the condenser lens group coming into contact with the phosphor can be reduced. Further, in combination with the fluorescent material provided on the inclined surface of the rotating body, this arrangement can reduce the risk of mechanical interference between the fixture for the condenser lens group 18 or the condenser lens group 19 and the rotating body 10.

The operation of each part of the light source device will be described below.

The blue laser light emitted from the excitation light source unit 14 passes through the dichroic mirror 16 and is condensed by the condenser lens group 18 to the red phosphor 12 in a ring shape provided on the inclined surface of the rotating body 10. The red light emitted from red phosphor 12 is condensed by condenser lens group 18, and then reflected toward light combiner 20 by dichroic mirror 16.

The blue laser light emitted from the excitation light source assembly 15 passes through the dichroic mirror 17 and is condensed by the condenser lens group 19 to the annular green phosphor 13 provided on the inclined surface of the rotating body 10. The green light emitted from green phosphor 13 is condensed by condenser lens group 19, and then reflected in the direction of light combiner 20 by dichroic mirror 17.

Dichroic mirror 16 and dichroic mirror 17 are arranged in a direction in which the optical paths of red light and green light reflected by the respective mirrors are orthogonal to each other. Further, the light combining mirror 20 is disposed so that red light reflected by the dichroic mirror 16 and green light reflected by the dichroic mirror 17 are superimposed on each other at the same position on the mirror surface. The light combining mirror 20 is disposed at a position where the rotation axis RA of the rotating body 10 is extended so that the mirror surface direction coincides with the rotation axis RA.

In the light combining mirror 20, since red light is reflected and green light is transmitted, the lights of the two colors are superimposed and combined. In the light source device of the present embodiment, since excitation light can be simultaneously and continuously emitted from the excitation light source unit 14 and the excitation light source unit 15 to the two color phosphors on the rotating body, the synthesized light can be output without interruption in time.

In the conventional light source device described with reference to fig. 12, there is a large distance difference between the optical path length from the fluorescent materials of the respective colors to the light combining mirror and the diameter of the annular pattern of the fluorescent materials.

In contrast, in the light source device of the present embodiment, the distance difference between the optical path from the red phosphor 12 to the light combining mirror 20 and the optical path from the green phosphor 13 to the light combining mirror 20 is only about the distance P between the annular patterns of the phosphors shown in fig. 1.

Although the diameter of the annular pattern has to be increased to some extent in order to prevent the phosphor from overheating, the distance P between the annular patterns of two colors may be made close. This is because the condenser lens group and the dichroic mirror corresponding to the red phosphor and the condenser lens group and the dichroic mirror corresponding to the green phosphor are arranged on the opposite side with the rotation axis RA therebetween, and therefore there is no fear of mechanical interference with each other, and there is no trouble even if P is reduced.

Therefore, in the light source device of the present embodiment, the difference in optical path length from the phosphors of different colors to the light combining mirror is significantly reduced as compared with the conventional one. Therefore, it is possible to realize a light source that can output high-quality illumination light having uniform angular characteristics and intensity distributions of the respective color components without providing an expensive adjustment optical system.

In the above embodiment, the red phosphor and the green phosphor are used, but a combination of colors other than those described above may be used according to the specifications required for the light source device. If the wavelength selectivity of the dichroic mirror and the light-combining mirror is appropriately changed according to the color combination of the fluorescent material, light source devices of various specifications can be realized.

Further, by controlling the output intensity of the excitation light from each excitation light source unit independently, the color balance of the synthesized light output from the light source device can be easily changed or adjusted. Such changes or adjustments may be made at appropriate timings.

[ second embodiment ]

A light source device according to a second embodiment of the present invention will be described with reference to fig. 2. The first embodiment is a light source device capable of outputting high-quality synthesized light in which the intensity distributions and angular characteristics of the red component and the green component are uniform, and the second embodiment has an optical system in which blue component light is superimposed on the synthesized light.

In fig. 2, 21 is a light source device, 10 is a rotating body, 11 is a motor, 12 is a red phosphor, 13 is a green phosphor, 14 and 15 are excitation light source components, 16 is a first dichroic mirror, 18 and 19 are condenser lens groups, 22 is a blue light source component, 23 is a second dichroic mirror, and 24 is a combiner mirror.

In the present embodiment, the portions that emit red and green light, that is, the rotating body 10, the motor 11, the red phosphor 12, the green phosphor 13, the excitation light source unit 14, the excitation light source unit 15, the first dichroic mirror 16, the condenser lens group 18, and the condenser lens group 19, have the same configuration as that of the first embodiment.

On the other hand, the present embodiment includes a blue light source unit 22. The blue light source unit 22 is not a light source for phosphor excitation, but a light source for superimposing blue light on red light and green light.

The dichroic mirror 23 transmits the output light of the excitation light source assembly 15 and the blue light source assembly 22, and reflects the green light emitted from the green phosphor 13. The mirror surfaces of dichroic mirror 16 and dichroic mirror 23 are arranged parallel to the rotation axis of the rotating body.

The light-combining mirror 24 reflects red light emitted from the red phosphor 12, and transmits output light of the blue light source unit 22 and green light emitted from the green phosphor 13.

The blue light source unit 22, the excitation light source unit 14, and the excitation light source unit 15 may use blue laser sources having the same emission wavelength, or may use laser sources having different wavelengths if the wavelength of the blue component of the synthesized light is different from the excitation wavelength of the phosphor. In order to match the beam form of the blue light incident on dichroic mirror 23 from blue light source assembly 22 with the red light incident on dichroic mirror 23 via condenser lens group 19, it is preferable to provide a shaping lens group and, in some cases, a diffuser plate or the like in blue light source assembly 22.

The light source device of the second embodiment having such a configuration is not only excellent in angular characteristics and intensity distribution of the combined light since the difference in optical path length from the red and green phosphors provided on the rotating body to the light combining mirror is small, as in the first embodiment, but also can be combined by further superimposing the blue laser light. When the excitation light source unit 14, the excitation light source unit 15, and the blue light source unit 22 are continuously turned on, output light obtained by superimposing red light, green light, and blue light can be continuously emitted from the light source device.

Further, by controlling the output intensities of the excitation light from the excitation light source units and the blue light source units independently, the color balance of the combined light output from the light source device can be easily changed or adjusted. Such changes or adjustments may be made at appropriate timings.

[ third embodiment ]

Fig. 3 shows, as a third embodiment, the overall configuration of a projection display device including a light source device 21 according to a second embodiment of the present invention.

As shown in fig. 3, a projection display device according to a third embodiment includes: a light source device 21; a relay lens 310; a first lens array 320; a second lens array 330; a polarization conversion device 340; a superimposing lens 350;

dichroic mirrors

360, 361; mirrors 362, 363, 364; a cross dichroic prism 370; a lens 381 for red; a transmissive liquid crystal panel 382 for red; a green lens 383; a transmissive liquid crystal panel 384 for green; a blue lens 385; a transmissive liquid crystal panel 386 for blue; a projection lens 390. There may be a case where the projection screen 391 is further provided.

The light source device 21 is the light source device described in the second embodiment, and can continuously output light obtained by superimposing red light, green light, and blue light.

Light emitted from the light source device 21 is guided to the first lens array 320 via the relay lens 310. The first lens array 320 includes a plurality of small lenses arranged in a matrix to divide light into a plurality of sub-beams. The second lens array 330 and the superimposing lens 350 form images of the lenslets of the first lens array 320 in the vicinity of the screen regions of the red, green, and blue transmissive

liquid crystal panels

382, 384, and 386. The first lens array 320, the second lens array 330, and the superimposing lens 350 make the light intensity of the light source device 21 uniform in the in-plane direction of the transmissive liquid crystal panel.

The polarization conversion device 340 converts the sub-beams divided by the first lens array 320 into linearly polarized light. The dichroic mirror 360 is a dichroic mirror that reflects red light and transmits green light and blue light. The dichroic mirror 361 reflects green light and transmits blue light. The

mirrors

362 and 363 are mirrors that reflect blue light. The mirror 364 is a mirror that reflects red light.

The linearly polarized red light enters the red transmissive liquid crystal panel 382 through the red lens 381, is modulated according to an image signal, and is emitted as image light. Further, an incident-side polarizing plate (not shown) and an exit-side polarizing plate (not shown) are disposed between the red lens 381 and the red transmissive liquid crystal panel 382, and between the red transmissive liquid crystal panel 382 and the cross dichroic prism 370, respectively. Similarly to red, green light is modulated by the transmissive liquid crystal panel 384 for green, and blue light is modulated by the transmissive liquid crystal panel 386 for blue, and is emitted as image light.

The cross dichroic prism 370 is formed by bonding four rectangular prisms, and a dielectric multilayer film is formed on the X-shaped interface of the bonded portion. The image light output from the transmissive liquid crystal panel 382 for red and the transmissive liquid crystal panel 386 for blue is reflected by the dielectric multilayer film toward the projection lens 390, and the image light output from the transmissive liquid crystal panel 384 for green is transmitted by the dielectric multilayer film toward the projection lens 390. The image lights of the respective colors are superimposed and projected onto a projection screen 391 through a projection lens 390.

As the projection display apparatus of the third embodiment, since the transmissive liquid crystal panels (light modulation devices) for respective colors are illuminated using the light source apparatus 21 of good quality in which the angular characteristics and the intensity distributions of respective color components are uniform, it is possible to realize image display with uniform color depth and high image quality.

Further, by controlling the output intensities of the excitation light and the blue light source unit from the respective excitation light source units independently, the color balance of the display image of the projection display device can be easily changed or adjusted. Such changes or adjustments may be made at appropriate timings.

[ fourth embodiment ]

A light source device according to a fourth embodiment of the present invention will be described with reference to fig. 4.

In the figure, 401 is a light source device, 40 is a rotating body, 41 is a motor, 42 is a phosphor portion color-divided and coated with a red phosphor and a green phosphor, 44 and 45 are excitation light source units, 46 is a first dichroic mirror, 47 is a second dichroic mirror, 48 and 49 are condenser lens groups, 50 is a light combining mirror, and 51 is a blue light source unit. RA is the rotation axis of the rotating body 40, EA3 is the optical axis of the condenser lens group 48, and EA4 is the optical axis of the condenser lens group 49.

In the present apparatus, a phosphor portion 42 is provided on a slope of a side portion of the rotating body 40 that can be rotated by the motor 41. In order to prevent the phosphor portion from overheating, a metal having high thermal conductivity is suitably used as a base material of the rotating body 40, and a concave portion for cooling is provided at the center of the upper surface.

The phosphor portion 42 is a ring-shaped region in which the red phosphor 42R and the green phosphor 42G are coated in a color separation manner. Fig. 5 (a) is a plan view of the rotating body 40 viewed from above the rotation axis, and an annular region centered on the rotation axis RA of the rotating body 40 is a phosphor portion 42, and the phosphor portion 42 is coated with red phosphor 42R and green phosphor 42G in divided halves. In other words, the red phosphor 42R and the green phosphor 42G are disposed in different regions on the same circumference.

The optical axis EA3 of the condenser lens group 48 and the optical axis EA4 of the condenser lens group 49 are disposed on opposite sides with respect to the rotation axis RA of the rotating body 40. In other words, when the rotating body 40 is viewed from above as shown in fig. 5 (a), the optical axis EA3 and the optical axis EA4 are arranged on opposite sides of the diameter of the annular fluorescent body portion 42 with the rotation axis RA therebetween. Therefore, as the rotating body 40 rotates, the red phosphor 42R and the green phosphor 42G are alternately positioned directly below the condenser lens group 48 and the condenser lens group 49, but the phosphors of the same color are not simultaneously positioned directly below the condenser lens group 48 and the condenser lens group 49.

Returning to fig. 4, an excitation light source unit 44 for exciting the red phosphor 42R and an excitation light source unit 45 for exciting the green phosphor 42G are provided with the rotation axis RA of the rotating body 40 interposed therebetween. Each excitation light source assembly has: a laser light source that emits light having a wavelength capable of exciting the phosphor; and an optical lens group for shaping the excitation light.

For example, a module having a plurality of blue laser light sources arranged in an array and a plurality of collimator lenses arranged corresponding to the respective blue laser light sources, in which the blue laser light sources and the collimator lenses are integrated, is suitably used. Each module includes a light emitting device array in which blue laser light sources are arranged in a matrix of 2 × 4. However, the size of the matrix arrangement included in one module is not limited to this example, and may be a larger-size matrix arrangement or a matrix arrangement in which the number of vertical and horizontal directions is the same. The blue laser light source used in the light source module is, for example, a semiconductor laser that emits light having a wavelength of 445 nm. The light output from each laser light source is emitted from the excitation light source assembly as substantially parallel light rays by the action of the lens group. The excitation light source assembly 44 and the excitation light source assembly 45 may have the same structure.

Between the excitation light source assembly 44 and the phosphor portion 42, a dichroic mirror 46 and a condenser lens group 48 are arranged. Further, a dichroic mirror 47 and a condenser lens group 49 are disposed between the excitation light source assembly 45 and the phosphor portion 42. The mirror surfaces of the dichroic mirror 46 and the dichroic mirror 47 are arranged parallel to the rotation axis RA of the rotating body.

The condenser lens group 48 is a lens group that condenses the excitation light from the excitation light source assembly 44 to irradiate the phosphor portion 42 and condenses and transmits the fluorescence to the dichroic mirror 46. Similarly, the condensing lens group 49 is a lens group that condenses excitation light from the excitation light source assembly 45 to irradiate the phosphor portion 42 and condenses and transmits fluorescence to the dichroic mirror 47. The condenser lens group 48 and the condenser lens group 49 are formed of two lenses in the example of fig. 4, but the number of lenses is not limited thereto. The condenser lens group 48 and the condenser lens group 49 may have the same structure.

The dichroic mirror 46 transmits the excitation light from the excitation light source unit 44 toward the phosphor portion 42, and reflects the red light emitted from the red phosphor 42R toward the light-combining mirror 50. The dichroic mirror 47 transmits the excitation light from the excitation light source unit 45 in the direction of the phosphor portion 42, and reflects the green light emitted from the green phosphor 42G in the direction of the light-combining mirror 50. The dichroic mirror 47 transmits light of the blue light source unit 51 in the direction of the light combining mirror 50.

The light combining mirror 50 is a dichroic mirror that reflects red light and transmits green light and blue light. The mirror surface of the light combining mirror 50 is arranged in a direction along the extension direction on the extension line of the rotation axis RA of the rotating body 40. When an angle formed by the mirror surface of the light combining mirror 50 with respect to the optical axis of the combined light described later is θ 6, θ 6 is set to 45 degrees.

In the present embodiment, the excitation light is condensed by the condenser lens group and irradiated to the phosphor provided on the inclined surface of the side portion of the rotating body 40. In the present embodiment, an angle θ 4 formed by the optical axis EA3 of the condenser lens group 48 and the rotation axis RA of the rotating body 40 is set to 10 degrees or more and 80 degrees or less. An angle θ 5 formed by the optical axis EA4 of the condenser lens group 49 and the rotation axis RA of the rotating body 40 is set to 10 degrees or more and 80 degrees or less. In addition, θ 4 and θ 5 are arranged to be the same except for manufacturing errors, and are set to 45 degrees in the present embodiment. In this way, by arranging the optical axis of the condenser lens group and the rotation axis at an angle other than parallel, even if the thrust of the motor in the axial direction is fluctuated, the risk of the condenser lens group coming into contact with the phosphor can be reduced. Further, in combination with the fluorescent material provided on the inclined surface of the rotating body, this arrangement can reduce the risk of mechanical interference between the fixing tool for the condenser lens group 48 or the condenser lens group 49 and the rotating body 40.

Next, the operation of each part of the light source device of the present embodiment will be described.

The light source device of the present embodiment is configured to be capable of switching output light of four colors of red (R), green (G), blue (B), and yellow (Y) in time series and outputting the light for use in a projection display device of a fifth embodiment described later.

In the light source device 401, a device capable of detecting the rotational position, such as a rotary encoder, is attached to the rotary body 40 in advance, so that the relative positional relationship between the red phosphor 42R and the green phosphor 42G applied in a color-separated manner, and the excitation light source unit 44 and the excitation light source unit 45 can be grasped. The lighting timing of the excitation light source unit 44, the excitation light source unit 45, and the blue light source unit 51 is controlled in synchronization with the rotation of the rotating body 40 on which the phosphors are applied in a color separation manner. With such a configuration, the light source device 401 can output light of different colors by switching the light in time series.

Referring to fig. 5 (b), the lighting timing of the excitation light source unit 44, the excitation light source unit 45, and the blue light source unit 51 will be described. In the four timing charts of fig. 5 (b), the horizontal axis represents time, and the length corresponding to one rotation of the rotating body 40 is shown. In other words, one of the scales dividing the horizontal axis into four in the figure corresponds to the phase at which the rotating body 40 rotates by 90 degrees.

The four timing charts are timing charts showing, in order from top to bottom, the color switching timing of the output light, the lighting timing of the blue light source assembly 51, the lighting timing of the excitation light source assembly 45, and the lighting timing of the excitation light source assembly 44 on the same time axis. The timing chart shown in fig. 5 (b) is an example of timing control, and the lighting order, the temporal length, the phase relationship, and the like are not limited to this example.

First, in order to cause the light source device 401 to output blue light, the blue light source assembly 51 is turned on, and the excitation light source assembly 44 and the excitation light source assembly 45 are turned off. The blue light emitted from the blue light source unit 51 is transmitted through the dichroic mirror 47 and the light combining mirror 50 and output from the light source device 401.

Next, in order to cause the light source device 401 to output green light, the excitation light source assembly 45 is turned on and the excitation light source assembly 44 and the blue light source assembly 51 are turned off in such a timing that the green phosphor 42G appears directly below the condenser lens group 49. The excitation light Ex emitted from the excitation light source assembly 45 passes through the dichroic mirror 47, and is condensed by the condenser lens group 49 to the green phosphor 42G provided on the inclined surface of the rotating body 40. The green light emitted from green phosphor 42G is condensed by condenser lens group 49, reflected in the direction of light combining mirror 50 by dichroic mirror 47, transmitted through light combining mirror 50, and output from light source device 401.

Next, in order for the light source device 401 to output yellow light, the excitation light source assembly 45 and the excitation light source assembly 44 are turned on and the blue light source assembly 51 is turned off at a timing at which the green phosphor 42G appears directly below the condenser lens group 49 and the red phosphor 42R appears directly below the condenser lens group 48.

The excitation light Ex emitted from the excitation light source assembly 45 passes through the dichroic mirror 47, and is condensed by the condenser lens group 49 to the green phosphor 42G provided on the inclined surface of the rotating body 40. The green light emitted from green phosphor 42G is condensed by condenser lens group 49, reflected in the direction of light combining mirror 50 by dichroic mirror 47, transmitted through light combining mirror 50, and output from light source device 401. At the same time, the excitation light Ex emitted from the excitation light source assembly 44 passes through the dichroic mirror 46, and is condensed by the condenser lens group 48 to the red phosphor 42R provided on the inclined surface of the rotating body 40. The red light emitted from the red phosphor 42R is condensed by the condenser lens group 48, reflected in the direction of the dichroic mirror 46 toward the light-combining mirror 50, further reflected by the light-combining mirror 50, and output from the light source device 401. That is, a yellow combined light in which green light and red light are superimposed is output from the light source device 401.

Next, in order to cause the light source device 401 to output red light, the excitation light source assembly 44 is turned on and the excitation light source assembly 45 and the blue light source assembly 51 are turned off in timing such that the red phosphor 42R appears directly below the condenser lens group 48. The excitation light Ex emitted from the excitation light source assembly 44 passes through the dichroic mirror 46, and is condensed by the condenser lens group 48 to the red phosphor 42R provided on the inclined surface of the rotating body 40. The red light emitted from the red phosphor 42R is condensed by the condenser lens group 48, reflected in the direction of the dichroic mirror 46 toward the light-combining mirror 50, further reflected by the light-combining mirror 50, and output from the light source device 401.

By rotating the rotary body on which the red phosphor 42R and the green phosphor 42G are applied in a color-separated manner and controlling the timing of lighting the excitation light source unit 44, the excitation light source unit 45, and the blue light source unit 51 in synchronization with this, it is possible to switch the output light of the four colors of red (R), green (G), blue (B), and yellow (Y) in time series and output the light continuously.

In the conventional light source device described with reference to fig. 12, there is a large distance difference about the diameter of the annular pattern of the fluorescent material in the optical path length from the fluorescent materials of the respective colors to the light combining mirror.

In contrast, in the light source device of the present embodiment, the distance difference between the optical path length from the red fluorescent material 42R to the light combining mirror 50 and the optical path length from the green fluorescent material 42G to the light combining mirror 50 can be made theoretically completely equal.

Therefore, in the light source device of the present embodiment, the optical path lengths from the phosphors of different colors to the light combining mirror can be made equal except for manufacturing errors. Therefore, it is possible to realize a light source capable of outputting high-quality illumination light with uniform angular characteristics and intensity distributions of the respective color components without providing an expensive adjustment optical system.

Further, it is not necessary to output yellow light by combining green light and red light, and the irradiation timing of the excitation light may be controlled so that only R, G, B three colors are output.

Further, by controlling the output intensities of the excitation light from the excitation light source units and the blue light source units independently, the color balance of the light output from the light source device can be easily changed or adjusted. Such changes or adjustments may be made at appropriate timings.

[ fifth embodiment ]

Fig. 6 shows, as a fifth embodiment, the entire configuration of a projection display device including a light source device 401 according to a fourth embodiment of the present invention.

As shown in fig. 6, a projection display device according to a fifth embodiment includes: a light source device 401; a relay lens 610; a relay lens 620; an optical channel 640; an illumination lens group 650; a light modulation device 660; a prism 671; a prism 672; and a projection lens 680. There may be a case where the projection screen 690 is further provided.

The relay lens 610 and the relay lens 620 are lenses for guiding and condensing the light emitted from the light source device 401 to an entrance port of the light tunnel 640. The relay lens does not necessarily have to be constituted by two lenses.

The illumination lens group 650 is a lens group that shapes light propagating through the light channel 640 into a beam suitable for illuminating the light modulation device 660, and is composed of a single or a plurality of lenses.

The prism 671 and the prism 672 together constitute a Total Internal Reflection (TIR) prism. The TIR prism totally internally reflects the illumination light to enter the light modulation device 660 at a predetermined angle, and transmits the reflected light modulated by the light modulation device 660 to the projection lens 680.

The light modulation Device 660 modulates incident light based on an image signal, and uses a Digital Micromirror Device (DMD) in which Micromirror devices are arranged in an array. Other reflective light modulation devices, such as reflective liquid crystal devices, may be used.

The projection lens 680 is a lens for projecting the light modulated by the light modulation device 660 into an image, and is composed of a single or a plurality of lenses.

The projection screen 690 is used when constituting a rear projection display device, and is often provided also in a front projection type, but is not necessarily provided when a user projects a picture onto an arbitrary wall surface or the like.

Further, when it is desired to further improve the color purity of the illumination light emitted from the light source device 401, the light color selection color wheel may be disposed between the relay lens and the light tunnel, and may be rotated in synchronization with the color switching timing of the light source device.

The overall operation of the projection display device will be described below.

Illumination light emitted from the light source device 401 is incident on a prism, which is a TIR prism, via the relay lens 610, the relay lens 620, the light tunnel 640, and the illumination lens group 650. The light reflected by the total reflection surface of the prism 671 is incident on the light modulation device 660 at a predetermined angle.

The light modulation device 660 has micromirror devices arranged in an array, and drives the micromirror devices in accordance with respective color component signals of an image in synchronization with color switching of illumination light to reflect image light at a predetermined angle toward the prism 671. The image light is transmitted through the prism 671 and the prism 672, guided to the projection lens 680, and projected onto the projection screen 690.

The projection display apparatus according to the fifth embodiment is capable of displaying a high-quality image with uniform colors because the light modulation device is illuminated using the light source apparatus 401 of good quality in which the angular characteristics and the intensity distribution of each color component are uniform.

[ sixth embodiment ]

Fig. 7 shows a modification of the second embodiment as a sixth embodiment.

In the second embodiment, the optical axis EA1 of the condenser lens group 18 is orthogonal to the optical axis EA2 of the condenser lens group 19. An angle θ 1 formed by the optical axis EA1 of the condenser lens group 18 and the rotation axis RA of the rotating body 10, an angle θ 2 formed by the optical axis EA2 of the condenser lens group 19 and the rotation axis RA of the rotating body 10, and an angle θ 3 formed by the mirror surface of the light combining mirror 24 with respect to the optical axis of the combined light are set to 45 degrees.

On the other hand, when such a light source device is mounted on a projection display device, there are cases where: in order to fit into the allocated installation space, there is a need to adjust the form of the light source device.

In order to meet such a demand, in the sixth embodiment, an angle at which the optical axis EA1 of the condenser lens group 18 intersects the optical axis EA2 of the condenser lens group 19 is set to 80 degrees. In addition, θ 1, θ 2, and θ 3 are set to 40 degrees. The mirror surfaces of dichroic mirror 16 and dichroic mirror 23 are arranged parallel to rotation axis RA of the rotating body.

Focusing on four straight lines of the optical axis EA1 of the condenser lens group 18, the optical path of red light from the dichroic mirror 16 to the light combining mirror, the optical axis EA2 of the condenser lens group 19, and the optical path of green light from the dichroic mirror 23 to the light combining mirror, the four straight lines form a square in the second embodiment, and form a parallelogram in the sixth embodiment.

In the sixth embodiment, although the distance difference between the optical path lengths from the phosphors of the respective colors to the light combining mirror is slightly longer than the distance P between the annular patterns of the phosphors, it can be made very small as compared with the conventional light source device described with reference to fig. 12. Therefore, even without providing an expensive adjustment optical system, it is possible to realize a light source capable of outputting high-quality illumination light with uniform angular characteristics and intensity distributions of the respective color components, and the degree of freedom in design when mounted on a projection display device is increased.

In the present embodiment, the angle at which the optical axis EA1 of the condenser lens group 18 intersects the optical axis EA2 of the condenser lens group 19 is set to 80 degrees, but the angle is not limited to this angle, and any arrangement may be used as long as the four straight lines described above form a parallelogram.

[ seventh embodiment ]

Fig. 8 shows a modification of the first embodiment as a seventh embodiment.

In the first embodiment, the optical axis EA1 of the condenser lens group 18 is orthogonal to the optical axis EA2 of the condenser lens group 19. An angle θ 1 formed by the optical axis EA1 of the condenser lens group 18 and the rotation axis RA of the rotating body 10, an angle θ 2 formed by the optical axis EA2 of the condenser lens group 19 and the rotation axis RA of the rotating body 10, and an angle θ 3 formed by the mirror surface of the light combining mirror 24 with respect to the optical axis of the combined light are set to 45 degrees. Further, the optical path length from the phosphors of the respective colors to the light combining mirror causes a difference in the distance P between the annular patterns of the phosphors, which is very small compared to the conventional device.

The seventh embodiment is intended to further shorten the distance of the optical path from the phosphors of the respective colors to the light combining mirror compared to the first embodiment.

In the seventh embodiment, the arrangement of the excitation light source unit 14 and the direction of the optical axis EA1 of the condenser lens group 18 are changed such that the optical path length from the dichroic mirror 16 to the light combining mirror 20 increases with respect to the optical path of the fluorescence from the red phosphor 83 on the side closer to the light combining mirror 20, out of the green phosphor 82 and the red phosphor 83. However, in the present embodiment, the mirror surfaces of the dichroic mirror 16 and the dichroic mirror 17 are also arranged parallel to the rotation axis RA of the rotating body.

In the present embodiment, the direction of the optical axis EA1 of the condenser lens group 18 is tilted by θ 7 in the counterclockwise direction in the drawing, compared to the first embodiment. When the distance from the red phosphor 83 to the dichroic mirror 16 is L and the distance between the red phosphor 83 and the green phosphor 82 is P, θ 7 is expressed as follows.

θ7＝ARCSIN(L/P)

As a result of tilting the optical axis EA1 of the condenser lens group 18 by θ 7, the optical path length of red light from the dichroic mirror 16 to the light combining mirror 20 is substantially equal to the optical path length of green light from the dichroic mirror 17 to the light combining mirror 20. Further, the distance from the red phosphor 83 to the dichroic mirror 16 is the same as the distance from the green phosphor 82 to the dichroic mirror 17 as L.

Therefore, in the present embodiment, the optical path length of red light from the red phosphor 83 to the combiner 20 can be made substantially equal to the optical path length of green light from the green phosphor 82 to the combiner 20.

In the first embodiment, since the angle θ 1 formed by the optical axis EA1 of the condenser lens group 18 and the rotation axis RA of the rotating body 10 is equal to the angle θ 2 formed by the optical axis EA2 of the condenser lens group 19 and the rotation axis RA of the rotating body 10, when the phosphors of two colors are provided on the inclined surface of the edge portion of the rotating body, both the two colors are provided on the inclined surface having the same inclination angle. In the present embodiment, the direction of the optical axis EA1 of the condenser lens group 18 is inclined by θ 7 as compared with the first embodiment, and the basal plane of the red phosphor 83 is made orthogonal to the optical axis EA1 so as not to decrease the emission efficiency of the fluorescence from the red phosphor 83. That is, the angle of the basal plane of the red phosphor 83 is inclined by θ 7 with respect to the angle of the basal plane of the green phosphor 82.

Specific examples of the present embodiment include: l is 22mm, P is 5mm, θ 1 is 58.137 degrees, θ 2 is 45 degrees, θ 3 is 45 degrees, and θ 7 is 13.137 degrees.

In contrast, in the light source device of the present embodiment, the distance difference between the optical path from the red phosphor 83 to the combiner 20 and the optical path from the green phosphor 82 to the combiner 20 can be substantially eliminated.

Therefore, in the light source device of the present embodiment, the difference in optical path length from the phosphors of different colors to the light combining mirror is significantly reduced as compared with the conventional one. Therefore, it is possible to realize a light source capable of outputting high-quality illumination light with uniform angular characteristics and intensity distributions of the respective color components without providing an expensive adjustment optical system.

[ eighth embodiment ]

Fig. 9 shows a modification of the first embodiment as an eighth embodiment. The eighth embodiment is also for reducing the difference in optical path length from the phosphors of the respective colors to the combiner further than the first embodiment. The eighth embodiment may also be referred to as a modification of the seventh embodiment.

In the seventh embodiment, the arrangement of the excitation light source unit 14 and the direction of the optical axis EA1 of the condenser lens group 18 are changed such that the optical path length from the dichroic mirror 16 to the combiner 20 increases with respect to the optical path of the fluorescence from the red phosphor 83 on the side close to the combiner, but the optical path of the fluorescence from the green phosphor 82 on the side far from the combiner is not changed as compared with the first embodiment. In other words, in the seventh embodiment, the influence of the distance P between the red phosphor and the green phosphor is reduced by increasing the optical path length of the red light.

In contrast, the eighth embodiment is designed to adjust the distance between the two optical paths in the direction in which the distance becomes equal by lengthening the optical path of the fluorescence from the fluorescent material on the side closer to the combiner and shortening the optical path of the fluorescence from the fluorescent material on the side farther from the combiner, based on the first embodiment.

As shown in fig. 9, in the present embodiment, the excitation light source assembly 14, the dichroic mirror 16, and the condenser lens group 18 bear the phosphor on the side far from the condenser lens 20, and the excitation light source assembly 15, the dichroic mirror 17, and the condenser lens group 19 bear the phosphor on the side close to the condenser lens 20. The mirror surfaces of the dichroic mirror 16 and the dichroic mirror 17 are arranged parallel to the rotation axis of the rotating body.

In the present embodiment, the direction of the optical axis EA1 of the condenser lens group 18 is tilted by θ 8 in the clockwise direction in the drawing, compared to the first embodiment. When the distance from the phosphor to the dichroic mirror 16 is L and the distance between the phosphor and the phosphor is P, θ 8 is expressed as follows.

θ8＝ARCSIN(2×L/P)

Meanwhile, in the present embodiment, the direction of the optical axis EA2 of the condenser lens group 19 is tilted by θ 8 in the clockwise direction in the drawing, compared to the first embodiment.

As a result of tilting the optical axis EA1 of the condenser lens group 18 and the optical axis EA2 of the condenser lens group 19 by θ 8, the optical path length T of red light from the dichroic mirror 16 to the light combining mirror 20 is substantially equal to the optical path length T of green light from the dichroic mirror 17 to the light combining mirror 20. The distance from each phosphor to each dichroic mirror is the same as L.

Therefore, in the present embodiment, the optical path length of red light from the fluorescent material to the light combining mirror can be made substantially equal to the optical path length of green light from the fluorescent material to the light combining mirror.

In the first embodiment, since the angle θ 1 formed by the optical axis EA1 of the condenser lens group 18 and the rotation axis RA of the rotating body 10 is equal to the angle θ 2 formed by the optical axis EA2 of the condenser lens group 19 and the rotation axis RA of the rotating body 10, when the phosphors of two colors are provided on the inclined surface of the edge portion of the rotating body, both the two colors are provided on the inclined surface having the same inclination angle. In the present embodiment, the direction of the optical axis EA1 of the condenser lens group 18 and the direction of the optical axis EA2 of the condenser lens group 19 are inclined by θ 8 as compared with the first embodiment, and the base surface of each color phosphor is made orthogonal to the optical axis of each condenser lens group so as not to reduce the emission efficiency of the fluorescence from the phosphor. That is, the basal plane of the phosphor constitutes a plane having different inclinations depending on the color.

Specific examples of the present embodiment include: 22mm, 5mm, 48mm, 38.475 degrees for θ 1, 51.525 degrees for

θ

2, 45 degrees for θ 3, and 6.525 degrees for θ 8.

In contrast, in the light source device of the present embodiment, the distance difference between the optical path from the red phosphor to the light combining mirror 20 and the optical path from the green phosphor to the light combining mirror 20 can be substantially eliminated.

[ ninth embodiment ]

Fig. 10 shows a modification of the first embodiment as a ninth embodiment. The ninth embodiment is also intended to further reduce the difference in optical path length from the phosphors of the respective colors to the combiner, compared to the first embodiment. The ninth embodiment may also be referred to as a modification of the eighth embodiment.

In the ninth embodiment, the arrangement relationship of the excitation light source assembly, the dichroic mirror, the condenser lens group, the light combining mirror, and the rotating body is the same as that in the eighth embodiment. That is, L, P, T, θ 1, θ 2, θ 3, and θ 8 will be omitted because the description thereof will be repeated.

The edge surface of the rotating body provided with the phosphor of the ninth embodiment is a curved surface that appears to be a circular arc (a part of a circle) when taken in cross section, unlike the eighth embodiment. That is, the inclined surface shape of the rotating body 100 is adjusted so that the base surface of the phosphor is positioned on a circle of radius L centered on the center of the

dichroic mirror

16 or 17.

In the light source device of the present embodiment, the distance difference between the optical path from the red phosphor to the light combining mirror 20 and the optical path from the green phosphor to the light combining mirror 20 can be substantially eliminated.

[ tenth embodiment ]

A modification of the fourth embodiment will be described as a tenth embodiment. Fig. 4 shows a basic structure of the light source device of the present embodiment. However, in the fourth embodiment, the phosphor portion 42 provided in the rotating body 40 is formed by applying the

phosphor portions

42R and 42G of different colors to the annular region around the rotation axis RA in a color-divided manner as shown in fig. 5 (a), but the present embodiment is different in that the annular region around the rotation axis RA of the rotating body 40 is formed by the phosphor portion 52 of the same emission color as shown in fig. 11 (a).

While the

phosphors

42R and 42G used in the fourth embodiment are preferably phosphors excellent in the emission characteristics of red and green, respectively, the phosphor portion 52 of the present embodiment is preferably a phosphor emitting yellow or white light and having a wide emission spectrum.

The dichroic mirror 46 used in the present embodiment transmits the excitation light from the excitation light source unit 44 toward the phosphor portion 52, and reflects the red light component of the fluorescence emitted from the phosphor portion 52 toward the light-combining mirror 50. The dichroic mirror 47 transmits the excitation light from the excitation light source unit 45 in the direction of the phosphor portion 52, and reflects the green light component of the fluorescence emitted from the phosphor portion 52 in the direction of the light combining mirror 50. The dichroic mirror 47 transmits light of the blue light source unit 51 in the direction of the light combining mirror 50.

The light source device of the present embodiment may be configured to be capable of switching output light of four colors, red (R), green (G), blue (B), and yellow (Y), in time series and outputting the light, as in the fourth embodiment, for use in the projection display device of the fifth embodiment. In this case, for example, as shown in fig. 5 (b), the lighting timing of the blue light source assembly 51, the excitation light source assembly 45, and the excitation light source assembly 44 may be controlled. Of course, the timing chart shown in fig. 5 (b) is an example of timing control, and the lighting order, the temporal length, the phase relationship, and the like are not limited to this example. Further, it is not necessary to output yellow light by combining green light and red light, and the irradiation timing of the excitation light may be controlled so that only R, G, B three colors are output.

However, in the case of the present embodiment, since the annular phosphor portions 52 are formed of the same type of phosphor, it is not necessary to synchronize the rotation of the rotating body with the light emission timing of each light source unit, unlike the fourth embodiment in which the phosphor is applied in a color separation manner. Therefore, in the fourth embodiment, the rotary encoder is attached to the rotary body, but this embodiment is not necessary, and the configuration and timing control of the apparatus can be simplified.

The light source device of the present embodiment may be used in place of the light source device 21 in the projection display device of the third embodiment shown in fig. 3. In this case, since it is not necessary to switch the color of the output light in time series, control can be performed as follows: as shown in fig. 11 (b), the blue light source unit 51, the excitation light source unit 45, and the excitation light source unit 44 are constantly turned on, and white light W is continuously output.

By controlling the output intensities of the excitation light from the excitation light source units and the blue light source units independently, the color balance of the light output from the light source device can be easily changed or adjusted. Such changes or adjustments may be made at appropriate timings.

In the light source device of the present embodiment, the distance difference between the optical path from the fluorescent material for red light to the light combining mirror 50 and the optical path from the fluorescent material for green light to the light combining mirror 50 can be substantially eliminated.

Therefore, in the light source device of the present embodiment, the difference in optical path length from the fluorescent material to the light combining mirror for light of different colors is significantly reduced as compared with the conventional one. Therefore, it is possible to realize a light source capable of outputting high-quality illumination light with uniform angular characteristics and intensity distributions of the respective color components without providing an expensive adjustment optical system.

[ other embodiments ]

The color and arrangement of the fluorescent material provided on the rotating body are not limited to the examples of the above embodiments. For example, instead of the red light-emitting or green light-emitting phosphor, a yellow light-emitting or white light-emitting phosphor may be provided.

The rotating body is preferably in a form in which a slope is formed on a side portion and the slope is coated with a phosphor, and the important point is that the phosphor is coated on a surface inclined with respect to the rotation axis, and an angle formed by the optical axis Ax-L of the condensing lens group and the rotation axis Ax-R of the rotating body may be set to 10 degrees or more and 80 degrees or less.

In addition, various heat dissipation structures for suppressing the temperature rise of the phosphor may be provided on the base body of the rotating body. As shown in the embodiment, the recess may be provided in the vicinity of the rotation axis on the surface opposite to the motor, or the recess may be provided on the surface closer to the motor. By providing the concave portion, the contact area between the base body and the air is increased, and an air flow is generated, thereby improving the heat dissipation effect.

All the light source devices described above can be used in a freely combined manner in either a projection display device having a reflective light modulation device or a projection display device having a transmissive light modulation device. The shape, size, combination, arrangement, and the like of the components of the light source device shown in all the embodiments can be appropriately changed according to various conditions such as the structure and specification of the projection display device to which the present invention is applied.

Claims

1. A light source device, comprising:

a rotating body which can rotate around a rotating shaft and at least one part of the side part of which is coated with a fluorescent body;

a first excitation light source for exciting the phosphor;

a second excitation light source for exciting the phosphor;

a first dichroic mirror that transmits excitation light from the first excitation light source and reflects at least a part of fluorescence from the phosphor;

a second dichroic mirror that transmits excitation light from the second excitation light source and reflects at least a part of fluorescence from the phosphor;

a first condenser lens group disposed between the first dichroic mirror and the phosphor;

a second condenser lens group disposed between the second dichroic mirror and the phosphor; and

a light-combining mirror that reflects the fluorescent light from the phosphor reflected by the first dichroic mirror and transmits the fluorescent light from the phosphor reflected by the second dichroic mirror,

the first excitation light source and the second excitation light source are disposed on opposite sides with respect to a rotation axis of the rotating body,

the mirror surface of the light combining mirror is arranged along the direction of the rotation axis on the extension line of the rotation axis of the rotating body.

2. The light source device according to claim 1,

an optical axis of the first condenser lens group intersects with a rotation axis of the rotating body at an angle of 10 degrees or more and 80 degrees or less,

an optical axis of the second condenser lens group intersects with a rotation axis of the rotating body at an angle of 10 degrees or more and 80 degrees or less.

3. The light source device according to claim 1 or 2,

mirror surfaces of the first dichroic mirror and the second dichroic mirror are parallel to a rotation axis of the rotating body.

4. The light source device according to claim 1,

further comprises a laser light source having an emission wavelength different from that of the phosphor,

and outputting the output light of the laser light source through the light combining mirror.

5. The light source device according to claim 1,

the phosphors include a first phosphor and a second phosphor having emission wavelength characteristics different from each other.

6. The light source device according to claim 5,

the first phosphor and the second phosphor are provided in different regions on the same circumference around a rotation axis of the rotating body.

7. The light source device according to claim 5,

the first fluorescent material is provided on the circumference of a first circle around the rotation axis of the rotating body,

the second phosphor is provided on a circumference of a second circle having a different radius from the first circle and centered on the rotation axis of the rotating body.

8. A projection display device is characterized by comprising:

the light source device of any one of claims 1 to 7;

a light modulation device; and

and a projection lens.