Source: https://patents.google.com/patent/JP2016157096A/en
Timestamp: 2019-12-14 19:02:07
Document Index: 605510794

Matched Legal Cases: ['art 15', 'art 16', 'art 15', 'art 15', 'art 16', 'art) 15', 'art) 16', 'art 15', 'art 5', 'art)\n13', 'art) 13', 'art)\n14', 'art. 4']

JP2016157096A - Illumination device and image projection device - Google Patents
Illumination device and image projection device Download PDF
JP2016157096A
JP2016157096A JP2015120888A JP2015120888A JP2016157096A JP 2016157096 A JP2016157096 A JP 2016157096A JP 2015120888 A JP2015120888 A JP 2015120888A JP 2015120888 A JP2015120888 A JP 2015120888A JP 2016157096 A JP2016157096 A JP 2016157096A
JP2015120888A
貴洋 加戸
2015-02-20 Priority to JP2015031828 priority Critical
2015-02-20 Priority to JP2015031828 priority
2015-06-16 Application filed by 株式会社リコー, Ricoh Co Ltd filed Critical 株式会社リコー
2016-02-09 Priority claimed from PCT/JP2016/000652 external-priority patent/WO2016132706A1/en
2016-09-01 Publication of JP2016157096A publication Critical patent/JP2016157096A/en
PROBLEM TO BE SOLVED: To provide an illumination device that allows illumination light to be more efficiently obtained.SOLUTION: An illumination device 1 to be used in a projection display device and the like is configured to include: a light source 10; and a light tunnel 14. The light tunnel 14 is configured to comprise: a light incident aperture part 15; a light emerging aperture part 16; a light guide route 17; a reflection surface 20 that surrounds the light guide route 17 from a side as an inner side surface; a phosphor layer 19 that is excited by excitation light LB from the light source 10, and generates fluorescence LF of a wavelength band different from the excitation light LB; a converging optical system 13 that causes the excitation light LB to be incident upon the light tunnel 14 so that the excitation light diffuses in the vicinity of the light incident aperture part 15 and the phosphor layer 19 is irradiated with the excitation light; and a wavelength selection element 21 that is provided in the vicinity of the light incident aperture part 15, and reflects the fluorescence LF to guide the fluorescence to a direction of the light emerging aperture part 16.SELECTED DRAWING: Figure 1
The present invention relates to an illumination device and an image projection device.
There is known a wavelength conversion technique in which fluorescent materials such as green and red are obtained by irradiating the fluorescent material with excitation light having a relatively short wavelength, such as a blue laser, and the fluorescent light is used as illumination light. Since an individual light source such as a blue laser is a light source device with good response, it is widely deployed as a light source of an image projection apparatus (hereinafter referred to as “projector”). An attempt has been made to efficiently extract various illumination lights such as green in a projector using this wavelength conversion technology.
In this case, since the illumination light can be efficiently guided to the display panel of the projector when the size of the light source is smaller, many products collect the excitation light and irradiate the phosphor. However, since the irradiation area of the excitation light to the phosphor is small and a necessary amount of fluorescence cannot be obtained, a projector in which the phosphor is arranged on a light guide member that guides illumination light has been developed (for example, Patent Document 1). 2).
In Patent Document 1, a light-transmitting rod as a light guide member containing a phosphor is used as a light tunnel, and excitation light is incident on the light tunnel so that the fluorescence generated in the light tunnel is converted into the light tunnel. A projector that takes out and emits light by the light guiding action is disclosed.
However, in Patent Document 1, since the fluorescence generated from the phosphor travels in the translucent rod containing the phosphor, the transmittance is reduced by that amount, and a loss of light guided to the exit exit occurs. There is a problem that high fluorescence cannot be obtained.
On the other hand, in Patent Document 2, a plurality of optical paths of excitation light are switched, and a plurality of phosphors applied in a light tunnel are sequentially irradiated with beam-like excitation light to obtain fluorescence having a necessary wavelength. A projector is disclosed. The fluorescence generated from the phosphor is reflected after being internally reflected several times to the exit of the light tunnel, and is emitted after the illumination distribution is made uniform, so that the fluorescence can be guided to the exit as illumination light. . Thus, it is desired to develop a technique that can obtain illumination light more efficiently.
This invention is made | formed in view of said situation, and it aims at providing the illuminating device which can obtain illumination light more efficiently.
In order to achieve the above object, an illumination device according to the present invention includes a light source that generates light of a predetermined wavelength band, a light incident unit that receives light, a light output unit that emits light, and light output from the light input unit. A light guide member having a light guide path extending to a portion, and the light guide member includes a wavelength conversion member that generates light converted into a wavelength band different from the light from the light source inside, The light incident part is characterized in that a wavelength selection part for transmitting the light from the light source and reflecting the wavelength-converted light is arranged.
ADVANTAGE OF THE INVENTION According to this invention, the illuminating device which can obtain illumination light more efficiently can be provided.
It is the schematic which shows the illuminating device which concerns on 1st Embodiment of this invention, (a) is an optical figure of an illuminating device, (b) is the top view which looked at the light tunnel of the illuminating device from the light-projection opening part side. It is. It is the schematic diagram which represented typically the state when excitation light was irradiated to a fluorescent particle and emitted fluorescence. It is an optical diagram of the illuminating device which concerns on 2nd Embodiment of this invention. It is an optical diagram of the illuminating device which concerns on 3rd Embodiment of this invention. It is an optical diagram of the illuminating device which concerns on 4th Embodiment of this invention. It is an optical diagram of the illuminating device which concerns on 5th Embodiment of this invention. It is an optical diagram of the illuminating device which concerns on 6th Embodiment of this invention. It is an optical diagram of the illuminating device which concerns on 7th Embodiment of this invention. It is an optical diagram of the illuminating device which concerns on 8th Embodiment of this invention. It is an optical diagram of the illuminating device which concerns on 9th Embodiment of this invention. It is an optical diagram of the image projection apparatus (projector) which concerns on 10th Embodiment of this invention. It is an optical diagram of the image projection apparatus (projector) which concerns on 11th Embodiment of this invention. It is an optical diagram of the image projection apparatus (projector) which concerns on 12th Embodiment of this invention. FIG. 14 is a plan view of the color wheel shown in FIG. 13.
Below, one Embodiment of the illuminating device which concerns on this invention is described, referring drawings. FIG. 1 is a diagram showing an outline of a lighting device 1 according to the first embodiment of the present invention. FIG. 1A is an optical diagram of the illuminating device 1, and FIG. 1B is a plan view of the light tunnel 14 used in the illuminating device 1 as viewed from the light emission opening 16 side.
As shown in FIG. 1A, the illumination device 1 according to the first embodiment includes a light source 10 that is an excitation light source that generates excitation light, and a condensing optical system that is an example of an incident unit and includes condensing elements 11 and 12. The system 13 includes a light tunnel 14 that is an example of a light guide member, and a wavelength selection element 21 that is an example of a wavelength selection unit.
The light source 10 generates light in the blue wavelength region as excitation light. By using a blue laser diode (hereinafter referred to as “blue LD”) that is a solid light emitting element as the light source 10, the light source 10 generates blue laser light having a wavelength of 400 nm to 470 nm as excitation light LB. Moreover, in 1st Embodiment, as shown in FIG. 1, it is set as the light source 10 which consists of only one blue LD, However, The light source 10 of this invention is not limited to this structure. For example, it is also possible to employ a configuration in which light emitted from a plurality of light sources is bundled and emitted using a light emitting array composed of a plurality of light sources such as blue LDs. Also, a plurality of light sources can be arranged and used in parallel. The same applies to the following embodiments.
The light source 10 is not limited to the blue LD, and a light emitting diode (LED) that generates blue light can also be used. Also, an LD or LED that generates light other than blue light, or an LD that generates an ultraviolet wavelength region can be used. Also, a combination of these can be used.
A condensing optical system 13, which is an example of an incident part (incident optical system), collects light from the light source 10 and guides it to the light tunnel 14. The condensing element 11 of the condensing optical system 13 collects the excitation light LB that diverges and exits from the light source 10 and extracts it as a parallel light flux. The excitation light LB converted into a parallel light beam is once condensed by the light collecting element 12 and then guided into the light tunnel 14 in a diverged state.
The condensing optical system 13 including the condensing elements 11 and 12 shows an example of the incident portion, and the incident portion of the present invention is not limited to this configuration. As long as the excitation light LB is guided into the light tunnel 14 in a diverged state, a condensing optical system including only one condensing element can be used, or a reflection mirror, a diffraction grating, or the like can be used.
The light tunnel 14 includes a light incident opening (light incident part) 15, a light emitting opening (light emitting part) 16, a light guide path 17 extending from the light incident opening 15 to the light emitting opening 16, An inner side surface surrounding the light guide path 17 from the side is configured. The light tunnel 14 guides (guides) the excitation light LB incident from the light incident opening 15 toward the light emitting opening 16 while reflecting the excitation light LB on the inner surface. Thus, the light tunnel 14 has a function of making the luminance distribution of light uniform, that is, a function of eliminating unevenness in the amount of light by repeatedly reflecting light inside.
The light tunnel 14 of this embodiment has the same diameter from the light incident opening 15 to the light emitting opening 16 as shown in FIG. In addition, the light tunnel 14 has a quadrangular cross-sectional shape perpendicular to the direction from the light incident opening 15 toward the light emitting opening 16 as shown in FIG. It is formed by. The reflective base material 18 is a member in which a reflective film 18b is provided inside a light-transmissive base material 18a such as a glass material.
The reflective film 18b of the reflective substrate 18 reflects the excitation light LB and the fluorescence LF. The reflective film 18b can be formed of a dielectric multilayer film, or can be formed of a metal coat such as an aluminum coat. Moreover, it can also form by installing a metal with a high reflectance.
Both ends in the longitudinal direction of the light tunnel 14 made of such a rectangular tube-shaped reflective base material 18 are opened as a light incident opening 15 and a light emitting opening 16. The aspect ratio of the light emission opening 16 is equal to the aspect ratio of the irradiated portion (for example, a light modulation element such as DMD of the image projection apparatus) irradiated with the illumination light emitted from the illumination device 1.
Further, the phosphor layer 19 as an example of the wavelength conversion member is formed on one whole (upper surface) of the four inner side surfaces of the reflective base material 18, and the phosphor layer 19 is not formed on the other three surfaces. The reflection surface 20 is configured to reflect light by 18 b and guide the light to the light emission opening 16. Note that the one surface provided with the phosphor layer 19 also reflects the fluorescence LF as the reflecting surface 20 by the action of the reflecting film 18b.
The phosphor layer 19 is excited by the excitation light LB to generate light (fluorescence LF) that has been wavelength-converted to a wavelength band different from that of the excitation light LB. As the fluorescent material of the phosphor layer 19, it is preferable to use a material that receives light having a short wavelength and emits light having a longer wavelength.
For example, when green light is emitted as illumination light, a fluorescent material that receives the excitation light LB and generates fluorescence LF including a green wavelength band (for example, wavelength 450 nm to 600 nm) can be used. In the case where red light is emitted as illumination light, a fluorescent material that generates fluorescence LF including a red wavelength band (for example, wavelength 580 nm to 750 nm) can be used. Moreover, when emitting yellow light as illumination light, the fluorescent material which produces | generates fluorescence LF containing a yellow wavelength band (for example, wavelength 450nm -750nm) can be used.
Thus, an appropriate fluorescent material can be used according to the illumination light emitted from the illumination device 1. In addition, a wavelength conversion member other than a phosphor may be used as long as the wavelength of the excitation light LB is converted to generate light having a wavelength band different from that of the excitation light LB.
The phosphor layer 19 can be formed by directly applying a fluorescent material to one surface of the inner side surface of the light tunnel 14. As another means for obtaining the phosphor layer 19, a fluorescent material can be contained in a binder or the like and applied. Moreover, a wavelength conversion member can also be comprised using the base material 18a which mixed the fluorescent material in the glass material instead of application | coating of a fluorescent material.
Moreover, the area | region which provides the fluorescent substance layer 19 is not limited only to one surface of the inner surface of the reflective base material 18, It can also provide in two adjacent surfaces or three surfaces. Note that the phosphor layer 19 may be provided on all four surfaces. However, considering that the fluorescent layer LF is generated from the fluorescent layer 19 with high luminous efficiency, and the generated fluorescent LF is reflected and efficiently guided to the light emitting opening 16, the region where the fluorescent layer 19 is provided is provided. It is preferable to have three or less surfaces, and more preferably 1/2 or less of the inner surface, that is, two surfaces or one surface.
In addition, a wavelength selection element 21 having optical characteristics that transmits the excitation light LB from the light source 10 and reflects the fluorescence LF generated from the phosphor layer 19 is disposed in the light incident opening 15 of the light tunnel 14. The wavelength selection element 21 is made of a member in which a wavelength selection film 21b that transmits the excitation light LB and reflects the fluorescence LF is deposited on a base material 21a made of a glass material or the like that transmits the excitation light LB. With this configuration, the excitation light LB passes through the wavelength selection element 21 and enters the light tunnel 14, but the fluorescence LF is reflected by the wavelength selection element 21 and guided toward the light emission opening 16.
In the illuminating device 1 according to the first embodiment having the above-described configuration, the excitation light LB generated from the light source 10 is converted into a parallel light flux by the condensing element 11. The excitation light LB that has become a parallel light beam is once condensed by the condensing element 12, passes through the wavelength selection element 21, and then is guided into the light tunnel 14 in a divergent state and provided on the inner surface of the light tunnel 14. The phosphor layer 19 is irradiated.
Thus, the excitation light LB is incident on the light tunnel 14 in a diverged state, so that the excitation light LB can be applied to a wide area on the phosphor layer 19, and the fluorescent light LF can be efficiently emitted from the phosphor layer 19. Can be generated. Further, since the phosphor layer 19 is provided on the entire inner surface, the light beam guided to the reflecting surface 20 on which the phosphor layer 19 is not disposed is also reflected by the reflecting surface 20 and then the phosphor layer. Therefore, the wavelength conversion efficiency of the excitation light LB by the phosphor layer 19 can be improved. The wavelength-converted fluorescent light LF is guided to the light output opening 16 while being reflected by the reflection surface 20 on the inner surface, and then exits from the light output opening 16.
Here, FIG. 2 shows a schematic diagram in which the fluorescent light P is irradiated with the excitation light LB and emits fluorescence LF. As shown in FIG. 2, when the excitation light LB is irradiated, the fluorescent particles P emit fluorescence LF in all directions of 360 degrees. That is, the rectilinearity of the excitation light LB disappears at that time, and the fluorescent particles P become a new light source and diffusely emit the fluorescent light LF.
The fluorescence LF generated from the phosphor layer 19 in the light tunnel 14 is also diffused in all directions at 360 degrees on the same principle. Therefore, there is also fluorescence LF that returns in the direction of the light incident opening 15. Such fluorescence LF is reflected by the wavelength selection element 21 disposed in the light incident opening 15 and guided in the direction of the light emitting opening 16.
As a result, the fluorescence LF emitted in the 360 degree direction can be directed to the light exit opening 16 of the light tunnel 14, and the fluorescence LF as illumination light can be extracted more efficiently. In addition, if the fluorescence LF returning to the direction of the light incident opening 15 is selectively extracted and guided to the direction of the light emitting opening 16, the wavelength selection unit selects the wavelength in the first embodiment and the subsequent embodiments. The configuration of the element 21 is not limited, and an appropriate configuration can be used.
As mentioned above, according to 1st Embodiment, the excitation light LB can be irradiated to the wider area | region of the fluorescent substance layer 19 as a wavelength conversion member by making it inject into the light tunnel 14 in the state which diverged the excitation light LB. . The fluorescence LF generated from the phosphor layer 19 is reflected by the reflection surface 20 on the inner side surface and guided toward the light exit opening 16. Further, the fluorescence LF is also reflected by the wavelength selection element 21 at the light incident opening 15, and is guided toward the light emitting opening 16 through the light tunnel 14. Therefore, more fluorescence LF can be obtained as irradiation light, and a brighter illumination device 1 can be provided. Moreover, such an illuminating device 1 can be used suitably for an image projection apparatus etc.
Next, a lighting device according to a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is an optical diagram of the illumination device 1A according to the second embodiment. The lighting device 1A of the second embodiment is the same as that of the first embodiment shown in FIG. 1 except that a tapered (pyramidal frustum) light tunnel 14A as shown in FIG. The basic configuration is the same as that of the lighting device 1. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. The same applies to the following embodiments.
The light tunnel 14 of the first embodiment uses a rectangular tube-shaped member having the same diameter from the light incident opening 15 to the light emitting opening 16 and having a rectangular side shape. On the other hand, in the light tunnel 14A of the second embodiment, the diameter of the light incident opening 15 is the smallest, the diameter gradually increases toward the light emitting opening 16, and the diameter is largest at the light emitting opening 16. This is a taper structure. Except for the taper structure, the light tunnel 14A of the second embodiment has the same configuration as the light tunnel 14 of the first embodiment, and the entire surface of the inner surface of the reflective substrate 18 is fluorescent. A body layer 19 is provided.
Even in the lighting device 1A of the second embodiment having the above-described configuration, a brighter product suitable for an image projection device or the like can obtain more fluorescence as irradiation light by the same operation as the lighting device 1 of the first embodiment. Can be provided. Furthermore, in the lighting device 1A of the second embodiment, the light tunnel 14A has a tapered structure, so that each time a plurality of fluorescent LFs that emit light in all directions of 360 degrees are reflected by the light guide path 17, the reflection angle is converted. It can be made to face the light exit opening 16 side. Further, when the fluorescence LF is emitted as illumination light, the angle characteristics are uniform and emitted. Therefore, it is possible to provide a lighting device 1A that is brighter and has better optical performance.
The light tunnel 14A may have a tapered structure in which the diameter of the light incident opening 15 is the largest, the diameter gradually decreases toward the light emitting opening 16, and the diameter becomes the smallest at the light emitting opening 16. . In this case, since the diameter of the light incident opening 15 where the excitation light LB is incident is large, the excitation light LB can be incident in a more divergent state to irradiate a wider area of the phosphor layer 19.
Next, an illuminating device according to a third embodiment of the present invention will be described with reference to FIG. FIG. 4 is an optical diagram of the illumination device 1B according to the third embodiment. The lighting device 1B of the third embodiment is a modification of the second embodiment including a light tunnel 14A having a tapered structure. The lighting device 1B of the third embodiment has the same basic configuration as that of the lighting device 1A of the second embodiment, except that the light tunnel 14B provided with the phosphor layer 19B having a configuration different from that of the phosphor layer 19 is used. Have. Hereinafter, a configuration different from the second embodiment will be described.
In the second embodiment, the phosphor layer 19 is provided on the entire inner surface of the four inner surfaces of the light tunnel 14A having a tapered structure. On the other hand, in the third embodiment, as shown in FIG. 4, a phosphor material is applied to the entire circumference of about half of the four inner side surfaces of the light tunnel 14B having a tapered structure on the light incident opening 15 side. A phosphor layer 19B is provided.
Even in the illumination device 1B of the third embodiment having the above-described configuration, a brighter product suitable for a display device or the like can obtain more fluorescent light LF as irradiation light by the same operation as the illumination device 1 of the first embodiment. Can be provided. Furthermore, by adopting a configuration in which the phosphor layer 19B is provided on the entire inner surface on the light incident opening 15 side, the wavelength-converted fluorescence LF collides with the phosphor layer 19B again. In this case, many fluorescent LFs are specularly reflected, but scattering due to fluorescent particles also occurs, so that a loss of reflection of the fluorescent LF can be prevented, and the fluorescent LF can be more efficiently guided to the light exit opening 16. The brighter lighting device 1B can be provided.
Next, the illuminating device which concerns on 4th Embodiment of this invention is demonstrated, referring FIG. FIG. 5 is an optical diagram of a lighting apparatus 1C according to the fourth embodiment. As shown in FIG. 5, the illumination device 1C of the fourth embodiment includes a light source 10, a condensing optical system 13 including condensing elements 11 and 12, a light tunnel 14C having a tapered structure, a wavelength selecting element 21, , And is configured.
The light tunnel 14C of the fourth embodiment has the same configuration as the light tunnel 14A of the second embodiment, but in the fourth embodiment, the excitation light LB from an oblique direction with respect to the central axis of the light tunnel 14C. Is incident.
In the first to third embodiments, the excitation light LB is incident substantially parallel to the central axis of the light tunnels 14, 14A, 14B. That is, the excitation light LB is incident in the light emission direction from the light emission opening 16. In this configuration, the light beam that passes through the vicinity of the optical axis may reach the light exit opening 16 directly without being irradiated or internally reflected on the phosphor layer 19.
On the other hand, in the fourth embodiment, the excitation light LB is obliquely directed toward the phosphor layer 19 from the side where the phosphor layer 19 is not provided in the light tunnel 14C via the light incident opening 15. The phosphor layer 19 is irradiated with the excitation light LB. To achieve this, as shown in FIG. 5, the light source 10 and the condensing optical system 13 composed of the condensing elements 11 and 12 are disposed on the side where the phosphor layer 19 is not provided, and the optical axis thereof is the light. It is arranged so as to be oblique with respect to the central axis of the tunnel 14C, that is, oblique with respect to the light emission direction from the light emission opening 16.
With this configuration, the excitation light LB emitted from the light source 10 is once condensed at the light incident opening 15 by the condensing optical system 13 and is guided to the phosphor layer 19 in a diverged state to irradiate the phosphor layer 19. To do. Therefore, it is possible to reduce the excitation light LB that directly reaches the light exit opening 16.
As described above, the illumination device 1C of the fourth embodiment can obtain more fluorescent light as irradiation light by the same operation as the illumination device 1 of the first embodiment, and provide a brighter product suitable for an image projection device or the like. can do. Furthermore, in the fourth embodiment, since the excitation light LB is obliquely incident on the central axis of the light tunnel 14C and guided to the phosphor layer 19, the excitation light LB is irradiated to the phosphor layer 19 throughout. Can do. Therefore, the wavelength conversion efficiency to the fluorescence LF is improved, more fluorescence can be efficiently obtained, and a brighter lighting device 1C can be provided.
In the fourth embodiment, the excitation light LB is directly guided to the phosphor layer 19 and efficiently wavelength-converted. Therefore, the phosphor layer 19 may be provided at least in a region where the excitation light LB is directly irradiated, the area of the phosphor layer 19 in the axial direction can be reduced, and the phosphor material can be reduced.
Next, an illuminating device according to a fifth embodiment of the present invention will be described with reference to FIG. FIG. 6 is an optical diagram of a lighting apparatus 1D according to the fifth embodiment. As shown in FIG. 6, the illumination device 1D of the fifth embodiment includes a light source 10, a condensing optical system 13 including condensing elements 11 and 12, a light tunnel 14D having a tapered structure, a wavelength selection element (wavelength And a wavelength selection film 21D as a selection unit).
In the first to fourth embodiments, the light incident opening 15 is provided at one end of the light tunnel 14, 14 </ b> A to 14 </ b> C on the light incident side. On the other hand, in the fifth embodiment, as shown in FIG. 6, the position near the one end portion on the light incident side and facing the phosphor layer 19D, that is, the reflective base material constituting the light tunnel 14D. A light incident opening 15 </ b> D is provided on the side surface of 18. In order to realize this, the light tunnel 14D is formed of the base material 18a through which the excitation light LB is transmitted, and a region where the reflection film 18b is not formed is provided on the inner side surface of the base material 18a facing the phosphor layer 19D. A light incident opening 15D through which the excitation light LB is transmitted is incident.
And in 5th Embodiment, it replaces with the wavelength selection element 21 which consists of the base material 21a and the wavelength selection film | membrane 21b, and has wavelength in the area | region which provided the light-incidence opening part 15D of the inner surface of the base material 18a of light tunnel 14D. A selection film 21D is provided as a wavelength selection element. In such a wavelength selection film 21D, the excitation light LB enters the light tunnel 14D from the light incident opening 15D, but the fluorescence LF emitted from the phosphor layer 19D and directed toward the wavelength selection film 21D is the wavelength selection film 21D. And is guided in the light tunnel 14 </ b> D in the direction of the light exit opening 16.
In the fifth embodiment, the light source 10 and the condensing optical system 13 including the condensing elements 11 and 12 are disposed so as to face the light incident opening 15D provided on the side surface of the light tunnel 14D. Then, as shown in FIG. 5, the direction of light (light tunnel) is oblique with respect to the light emitting direction from the light emitting opening 16 so that the optical axis of the excitation light LB is in the direction of the normal line of the light incident opening 15D. The excitation light LB is incident from an oblique direction with respect to the central axis of 14D.
With this configuration, also in the fifth embodiment, more light beams of the excitation light LB can be directly guided to the phosphor layer 19D, and the fluorescence LF can be efficiently generated. Furthermore, since the phosphor layer 19D can be irradiated with the excitation light LB at a larger angle compared to the fourth embodiment, the area in the axial direction of the phosphor layer 19D should be narrower than that of the fourth embodiment. Is also possible.
Therefore, in the fifth embodiment, the phosphor layer 19D is provided not in the entire inner surface of the light tunnel 14D but in a portion of the inner surface that includes the irradiation region of the diverging excitation light LB. ing. The inner surface other than the region where the phosphor layer 19D and the light incident opening 15D are provided is a reflection surface 20 provided with a reflection film 18b that reflects the excitation light LB and fluorescence.
In addition, the light tunnel 14D is closed without opening one end portion on the incident side, and the reflection film 18b is formed on the inner side surface of the light tunnel 14D, thereby reflecting the fluorescent light LF traveling toward the one end portion side, so that the light emission opening portion 16 is formed. Can be led in the direction of
As described above, also in the illumination device 1D of the fifth embodiment, more fluorescence can be obtained as irradiation light by the same operation as that of the illumination device 1 of the first embodiment. Moreover, the phosphor layer 19D can be irradiated with the excitation light LB throughout, and the wavelength conversion to the fluorescence LF can be improved, and a brighter product suitable for an image projection apparatus or the like can be provided. Furthermore, in the fifth embodiment, since the wavelength selection film 21D is provided on the substrate 18a of the light tunnel 14D by vapor deposition or the like, the number of parts and assembly man-hours can be reduced. Moreover, the usage-amount of the fluorescent material of the fluorescent substance layer 19D can also be suppressed to the minimum.
Next, an illuminating device according to a sixth embodiment of the present invention will be described with reference to FIG. FIG. 7 is an optical diagram of a lighting apparatus 1E according to the sixth embodiment. The illumination device 1E of the sixth embodiment is a modification of the fifth embodiment, and without using the condensing optical system 13, the light source 10E of the excitation light LB that diverges, such as an LED, with respect to the light incident opening 15E. It is the structure which arranged directly.
Also in the sixth embodiment, the light incident opening 15E is provided on the side surface of the light tunnel 14E having a taper structure, and the excitation light LB is transmitted and the fluorescence LF is reflected in the region where the light incident opening 15E is provided on the substrate 18a. A wavelength selection film 21E is provided. Then, a light source 10E is arranged in the vicinity of the light incident opening 15E provided with the wavelength selection film 21E, and is oblique to the light emitting direction from the light emitting opening 16 (on the central axis of the light tunnel 14E). On the other hand, the excitation light LB is incident from an oblique direction.
A phosphor layer 19E is provided in the irradiation region of the excitation light LB. Since the excitation light LB from the light source 10E of the fifth embodiment is incident in a more divergent state and the irradiation area can be made wider, the area of the phosphor layer 19E is made wider than that of the fourth embodiment. Further, the inner side surface other than the region where the light incident opening 15E is provided is a reflection surface 20 provided with a reflection film 18b that reflects the excitation light LB and the fluorescence LF.
With this configuration, the excitation light LB emitted from the light source 10E directly enters the light tunnel 14E from the light incident opening 15E in a diverged state. Therefore, in the present embodiment, the light source 10E functions as an incident unit that causes the excitation light LB to be incident in a diverged state. Since the phosphor layer 19E is disposed at the travel destination of the diverging excitation light LB, more excitation light LB can be directly guided to the phosphor layer 19E, and the excitation light LB is wider. The phosphor layer 19E can be irradiated in the irradiation region.
As described above, also in the lighting device 1E of the sixth embodiment, more fluorescence LF can be obtained as irradiation light by the same operation as that of the lighting device 1 of the first embodiment. In addition, the phosphor layer 19E can be irradiated with the excitation light LB throughout, the wavelength conversion efficiency to the fluorescence LF is improved, and a brighter product suitable for an image projection apparatus or the like can be provided. In addition, since an optical system that guides the excitation light LB emitted from the light source 10E to the light incident opening 15E is not required, and the efficiency loss is suppressed as much as possible, a more efficient illumination device 1E can be obtained.
In the sixth embodiment, a flat plate diffraction grating or the like may be disposed between the light source 10E and the light incident opening 15E so that the diverging excitation light LB has high directivity to some extent. The phosphor layer 19E can be more efficiently irradiated with the excitation light LB.
In addition, the light tunnel 14E may be configured to include a wavelength selection film 21E that transmits the excitation light LB and reflects the fluorescence LF over the entire inner surface of the base material 18a that transmits the excitation light LB. With this configuration, only the fluorescence can be reflected and efficiently guided toward the light emission opening 16, and the excitation light LB can be prevented from being emitted from the light emission opening 16.
Next, an illuminating device according to a seventh embodiment of the present invention will be described with reference to FIG. FIG. 8 is an optical diagram of a lighting apparatus 1F according to the seventh embodiment. In addition to the basic configuration similar to that of the lighting device 1A of the second embodiment shown in FIG. 3, the lighting device 1F of the seventh embodiment has a light exit side of the light tunnel 14F as shown in FIG. A second wavelength selection element (wavelength selection unit) 22 is arranged in the emission aperture 16. Furthermore, in the seventh embodiment, the one surface provided with the phosphor layer 19 of the light tunnel 14F is formed of a reflective base material 18 ′ made of a metal plate having a high reflectance such as aluminum (Al). The metallic inner surface of the reflective substrate 18 ′ acts as the reflective surface 20, and the fluorescent LF generated from the phosphor layer 19 can be efficiently guided toward the light exit opening 16. The three surfaces other than the reflective base material 18 ′ are formed of a reflective base material 18 in which a reflective film 18b is provided on a base material 18a made of a glass material or the like.
The second wavelength selection element 22 is made of a member in which a base material 22a made of a glass material or the like is provided with a wavelength selection film 22b that reflects the excitation light LB and transmits the fluorescence LF. The second wavelength selection element 22 emits the fluorescence LF from the light exit opening 16, but the excitation light LB is reflected back into the light tunnel 14F.
In the light tunnel 14 </ b> F, the excitation light LB remaining without being wavelength-converted is present in the light that is reflected several times and is emitted from the light emission opening 16. Further, as described above, among the excitation light LB incident from the light incident opening 15, there are not a few excitation lights LB that reach the light emission opening 16 directly without being internally reflected. The excitation light LB does not contribute to wavelength conversion, and also affects the wavelength purity of the wavelength-converted fluorescence LF.
Therefore, in the seventh embodiment, the second wavelength selection element 22 disposed in the light emission opening 16 reflects such excitation light LB back into the light tunnel 14F, thereby using it as the excitation light LB again. Making it possible.
As described above, the illumination device 1F of the seventh embodiment can obtain more fluorescent light as irradiation light by the same operation as the illumination device 1 of the first embodiment, and provides a brighter product suitable for an image projection device or the like. can do. Furthermore, in the seventh embodiment, the fluorescence LF can be efficiently reflected and guided to the light exit opening 16 to be emitted. Further, the second wavelength selection element 22 disposed in the light emission opening 16 can reflect the excitation light LB reaching the light emission opening 16 toward the light tunnel 14F and use it again as the excitation light LB. . Therefore, it is possible to obtain the lighting device 1F with higher wavelength conversion efficiency to the fluorescence LF.
Next, an illuminating device according to an eighth embodiment of the present invention will be described with reference to FIG. FIG. 9 is an optical diagram of a lighting apparatus 1G according to the eighth embodiment. As shown in FIG. 9, the illuminating device 1G of the eighth embodiment includes a light source 10, a condensing optical system 13 including condensing elements 11 and 12, a light tunnel 14G having a tapered structure, a wavelength selecting element 21, and the like. And a heat sink 23 which is an example of a heat dissipation structure. The light tunnel 14 </ b> G includes a light incident opening 15, a light emitting opening 16, a light guide path 17, a phosphor layer 19, and a reflecting surface 20. One surface of the light tunnel 14G on which the phosphor layer 19 is provided is formed of a reflective base material 18 ′ made of a metal plate having a high reflectance such as aluminum and a high thermal conductivity.
The heat sink 23 is arranged on the outer surface of the reflective base material 18 opposite to the inner surface on which the phosphor layer 19 is provided. The heat sink 23 is not particularly limited, and any conventionally known appropriate material can be used. For example, by using an aluminum material, the heat sink 23 is light and excellent in heat dissipation. Further, in the present embodiment, by reducing the thickness of the wall surface on which the phosphor layer 19 and the heat sink 23 of the reflective base material 18 are disposed, heat conduction from the reflective base material 18 to the heat sink 23 is promoted, and the heat sink 23 is By providing, it suppresses that the light tunnel 14G becomes bulky.
In addition, it is preferable that the light tunnel 14G is formed of the reflective base material 18 having high thermal conductivity on three surfaces other than the substrate 18 'provided with the phosphor layer 19. The material of the reflective base material 18 having high thermal conductivity is not particularly limited, and a conventionally known appropriate material such as a base material 18a obtained by mixing a glass material with a metal material and a reflective film 18b is used. be able to.
Here, in each embodiment of the present invention, an example in which the phosphor layer 19 made of a phosphor is used as the wavelength conversion member is given, but the quantum efficiency of the phosphor is said to be 70% or 80% at the highest. ing. Unless the quantum efficiency is 100%, the unconverted energy is absorbed and becomes heat. This heat may increase the temperature of the phosphor and affect the conversion efficiency.
On the other hand, in the eighth embodiment, the heat generated from the phosphor of the phosphor layer 19 is transferred to the highly heat-reflecting reflective base material 18 'where the phosphor layer 19 is disposed, and then Heat is efficiently radiated to the outside by the heat sink 23 provided on the outer surface of the reflective substrate 18. Therefore, the temperature rise of the phosphor layer 19 can be suppressed.
As described above, the illumination device 1G of the eighth embodiment can obtain more fluorescent light as irradiation light by the same operation as the illumination device 1 of the first embodiment, and provide a brighter product suitable for an image projection device or the like. can do. Further, in the eighth embodiment, the use of the reflective base materials 18 and 18 ′ having high thermal conductivity and the heat sink 23 can suppress the temperature rise of the phosphor, and the phosphor layer 19 is more stable. Wavelength conversion is possible. As a result, it is possible to provide a highly reliable and bright illumination device 1G that is unlikely to cause a decrease in brightness even when continuously lit.
In each of the above embodiments, the light guide member is a light tunnel, but the light guide member of the present invention is not limited to the light tunnel. As another example of the light guide member, a light tunnel configured in a column shape with a transparent medium can be used. Further, the glass member itself containing the phosphor can be configured as a light tunnel.
Next, an illuminating device according to a ninth embodiment of the present invention will be described with reference to FIG. FIG. 10 is an optical diagram of a lighting apparatus 1H according to the ninth embodiment. As shown in FIG. 10, the illumination device 1H according to the ninth embodiment includes two light sources 10H, a light diffusing member (for example, a concave lens) 13H disposed in the optical path of each light source 10H, and a light tunnel having a tapered structure. 14H. The light diffusing member 13H is not limited to a concave lens, and may be a convex lens. The divergent light once condensed by this convex lens can be used. Moreover, what is necessary is just to be able to diffuse light, and you may use the diffusion member without a condensing capability.
The light tunnel 14H is formed of a truncated pyramidal base material 18a 'containing a phosphor 19H' and has a tapered structure having a hexahedron. The light tunnel 14H includes at least a surface on which the excitation light LB is incident, a surface that reflects the fluorescence LF wavelength-converted by the excitation light LB, and a surface that extracts the fluorescence LF.
In the present embodiment, a color selection filter (wavelength selection unit) 21H that transmits the excitation light LB and reflects the fluorescence LF is disposed on one surface (the lower surface in FIG. 10) of the four side surfaces of the light tunnel 14H. Are functioning as a light incident part (light incident surface) 15H for allowing excitation light to enter. Further, the reflection surface 20 is configured by providing a reflection layer 18b 'for reflecting the excitation light LB and the fluorescence LF on the surface (upper surface in FIG. 10) facing the light incident portion (light incident surface) 15H. In the present embodiment, the reflection surface 20 is configured by providing the reflection layer 18b 'on the other two side surfaces. Further, the surface on the rear end side of the light tunnel 14H is a light emitting portion (light emitting surface) 16H that selectively extracts and emits light by transmitting the fluorescence LF.
The two light sources 10H are arranged on the side surface of the light tunnel 14H and facing the light incident portion 15H. As the light source 10H, an LED that emits blue excitation light LB can be used, or a semiconductor light source such as an LD can be used. In the present embodiment, two light sources 10H are arranged. However, only one light source 10H may be arranged, or three or more light sources 10H may be arranged.
Between each light source 10H and the light incident portion 15H of the excitation light LB, a light diffusion member (incident portion) 13H that diffuses the excitation light LB and makes it incident on the light tunnel 14H is disposed. Since the light diffusing member 13H plays a role of expanding the light distribution of the excitation light LB emitted from the light source 10H, the excitation light LB enters the light tunnel 14H more uniformly, and can efficiently irradiate the phosphor 19H ′. .
In the present embodiment, a concave lens is used as the light diffusing member 13H. However, the present application is not limited to this. For example, the light diffusing member 13H may be configured to diverge once after being condensed by the convex lens. A light diffusing member with unevenness can also be used.
Further, when an LED is used as the light source 10H, the LED itself is a divergent light source, and therefore it is not always necessary to provide the light diffusing member 13H. When an LD is used as the light source 10H, it is preferable to use the light diffusing member 13H, and the effect of the light diffusing member 13H can be maximized.
The color selection filter 21H is formed of a dielectric multilayer film, and is formed directly on the light incident portion 15H of the base material 18a 'containing the phosphor 19H' of the light tunnel 14H. However, the present application is not limited to this, and for example, a transparent substrate provided with a color selection filter can be disposed between the light source 10H and the light incident portion 15H. At that time, it is more preferable to dispose a color selection filter so as to be in close contact with the base material 18a 'of the light tunnel 14H.
When the excitation light LB transmitted through the color selection filter 21H enters the light tunnel 14H, the phosphor 19H ′ contained in the base material 18a ′ of the light tunnel 14H is excited by the excitation light LB and is different from the excitation light LB. Fluorescent light LF that has been wavelength-converted to a wavelength band is emitted. In this embodiment, the phosphor 19H ′ that emits the fluorescence LF including the wavelength band of the green component and the red component is used. However, since the conversion efficiency is high and high luminance is obtained, the yellow phosphor 19H ′ is desirable. Among the yellow phosphors 19H ′, the YAG single crystal phosphor has particularly high heat resistance, and even when it generates heat upon irradiation with the excitation light LB, the conversion efficiency due to heat generation hardly occurs, so that it is most preferably used. Can do.
As a specific example of the light tunnel 14H containing the phosphor 19H ′, for example, a YAG single crystal phosphor is used as the base material 18a ′, and this is processed into a tapered structure (pyramidal frustum) or the like. Can do. Further, the light tunnel 14H can be formed by containing the phosphor 19H 'in the glass member. Inside the glass member, the wavelength of the excitation light LB is converted by the phosphor 19H ′ that has received the excitation light LB.
The fluorescent light LF emitted from the fluorescent material 19H ′ directly reaches the light emitting portion 16H and is emitted to the outside, or is reflected by the reflective layer 18b ′ (reflecting surface 20) and within the light guide path 17 of the light tunnel 14H. Is guided and emitted from the light emitting portion 16H.
In the present embodiment, the reflective layer 18b ′ is provided on the surface (upper surface) opposite to the surface functioning as the light incident portion 15H and on both surfaces, but if provided on at least one of these surfaces. Good. Further, the light tunnel 14H is not limited to the tapered structure, and may be a quadrangular prism or the like.
Also in the ninth embodiment, the second color selection that reflects the wavelength band of the excitation light LB and transmits the wavelength band of the fluorescence LF so that part or all of the excitation light LB that is not converted to the fluorescence LF is not emitted. The portion can be provided in the light emitting portion 16H.
As described above, the illumination device 1H of the ninth embodiment can obtain more fluorescent light as irradiation light by the same operation as that of the illumination device 1 of the first embodiment, and provides a brighter product suitable for an image projection device or the like. can do. Furthermore, in the ninth embodiment, high-luminance illumination can be achieved by using the yellow phosphor 19H ′ having high conversion efficiency that emits fluorescence including a red component and a green component. In particular, by using a single crystal yellow YAG phosphor having high heat resistance, it is difficult to cause a decrease in quantum efficiency due to heat, and it is possible to realize a lighting device 1H with higher luminance.
Moreover, since the illuminating devices 1-1H of each said embodiment are used suitably for an image projection apparatus, for example, the cross-sectional shape of the light tunnels 14-14H which are light guide members of the light modulation element which is an irradiated part is shown. It is a quadrangle equivalent to the aspect ratio. However, the cross-sectional shape of the light guide member of the present invention is not limited to a quadrangle, and it is possible to efficiently irradiate the irradiated portion with illumination light by setting the shape appropriately according to the shape of the irradiated portion. can do. In this case, when the phosphor layer is provided on the light guide member as in the lighting devices 1 to 1G, from the light incident opening (light incident part) to the light emitting opening (light emitting part) on the inner side surface in the axial direction. It is preferable to provide a wavelength conversion member such as a phosphor layer in a region of about ¼ to ½ along. Alternatively, it is preferable to provide a wavelength conversion member on the entire surface on the light incident opening side of the inner surface.
Next, an embodiment of the image projection apparatus of the present invention provided with the illumination device as described above will be described. The image projection apparatus according to the tenth embodiment will be described below with reference to FIG. FIG. 11 is an optical diagram of a projector 100 as an image projection apparatus according to the tenth embodiment.
As shown in FIG. 11, the projector 100 according to the tenth embodiment includes an illuminating device 1A, a red light source 2-1 as a second light source (illuminating device), and a blue light source 2- as a third light source (illuminating device). 2, condensing elements 3-1, 3-2, 3-3, 3-4, 3-5 and dichroic mirrors 4-1 and 4-2 as a relay optical system, an image generation unit 5, and projection optics A system 6, a control unit 7, a lighting drive unit 8, and the like are provided. The projector 100 is an apparatus that projects and enlarges an image on a screen Sc that is a projection surface.
In the present embodiment, the lighting device 1A of the second embodiment described above is used as the lighting device, but the lighting devices 1, 1B to 1G of the first, third to eighth embodiments can also be used. Moreover, in this embodiment, the fluorescent material which produces green fluorescence is used as the fluorescent substance layer 19 of 1 A of illuminating devices. Therefore, the illuminating device 1 </ b> A emits green illumination light (hereinafter referred to as “green light LG”) from the light emission opening 16.
The red light source 2-1 emits red light (hereinafter referred to as “red light LR”) as illumination light, and the blue light source 2-2 is blue light (hereinafter referred to as “blue light LB”) as illumination light. Is emitted. As the red light source 2-1 and the blue light source 2-2, a laser diode (LD) or a light emitting diode (LED) that generates laser light of a red component and a blue component can be used, respectively. The red light source 2-1 preferably generates light including a wavelength range of 620 nm to 750 nm, for example. For example, the blue light source 2-2 preferably generates light including a wavelength in the range of 400 nm to 470 nm.
The condensing elements 3-1, 3-2, and 3-3 collect the green light LG, the red light LR, and the blue light LB, respectively, and make them enter the dichroic mirrors 4-1, 4-2. The dichroic mirror 4-1 transmits the green light LG, reflects the blue light LB, and guides each to the light condensing element 3-4. The dichroic mirror 4-2 transmits the green light LG, reflects the red light LR, and guides each to the condensing element 3-5. The condensing elements 3-4 and 3-5 relay the green light LG, the blue light LB, and the red light LR, which are illumination lights, and guide them to the image generation unit 5.
In addition, a light tunnel can be arranged between the light condensing element 3-4 and the light condensing element 3-5 as an illumination light uniformizing means, and more uniform illumination light can be obtained by suppressing unevenness in the amount of light. Can be obtained.
The image generation unit 5 forms a full-color image based on the image generation data using the illumination light guided by the relay optical system from the illumination device 1A, the red light source 2-1, and the blue light source 2-2. The image generation unit 5 includes a reflection mirror 5-1 on which the illumination light guided from the relay optical system is incident, a concave mirror (mirror) 5-2 that reflects the illumination light reflected by the reflection mirror 5-1, and the concave mirror 5. -2 to which the illumination light reflected by -2 is irradiated.
The light modulation element 5-3 is controlled by the control unit 7, and forms a color projection image by gradation-controlling each illumination light of the green light LG, the red light LR, and the blue light LB for each pixel. In this embodiment, a DMD (Digital Micromirror Device) is used as the light modulation element 5-3. However, the light modulation element 5-3 is not limited to the DMD, and a liquid crystal or the like can be used.
The projection optical system 6 projects the projection image generated by the light modulation element 5-3 of the image generation unit 5 onto the screen Sc. The projection optical system 6 includes a fixed lens group provided in the fixed lens barrel and a movable lens group provided in the movable lens barrel. By moving this movable lens group, it is possible to perform focus adjustment and zoom adjustment.
The control unit 7 controls the overall operation of the projector 100. The hardware configuration of the control unit 7 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The control unit 7 drives and controls each unit of the projector 100 using the RAM as a work memory according to a program stored in advance in the ROM.
That is, the control unit 7 turns on the light source 10, the red light source 2-1, and the blue light source 2-2 of the lighting apparatus 1 A, the light modulation element 5-3 of the image generation unit 5, and the projection optical system 6. Connected to a driving mechanism of the movable lens group. Thereby, the control unit 7 controls the emission of the light sources 10 2-1 and 2-2 by the lighting driving unit 8, the generation control of the projection image in the light modulation element 5-3 of the image generation unit 5, and the projection optical system 6. Executes adjustment control for focus adjustment and zoom adjustment.
The control unit 7 is connected to an external information device such as a personal computer via an interface, and takes in image data and the like from an image information source (storage unit) 9 of the external information device. The control unit 7 performs appropriate image processing on the captured image data, and generates image generation data suitable for generating a projection image by the light modulation element 5-3 of the image generation unit 5. Next, the control unit 7 generates a drive signal for driving the image generation unit 5 based on the generated image generation data, and outputs the drive signal to the image generation unit 5.
In the projector 100 according to the tenth embodiment having the above-described configuration, the green light LG emitted from the light emission opening 16 by the illumination device 1A is collected by the light collecting element 3-1, and the dichroic mirrors 4-1, 4 are used. -2 is transmitted. Thereafter, the green light LG is relayed by the condensing elements 3-4 and 3-5, reflected by the reflecting mirror 5-1 and the concave mirror 5-2 of the image generating unit 5, and illuminates the light modulating element 5-3. .
Similarly, the blue light LB emitted from the blue light source 2-2 is condensed by the condensing element 3-3, reflected by the dichroic mirror 4-1, and relayed by the condensing elements 3-4 and 3-5. Then, the light enters the image generator 5. Thereafter, the blue light LB is reflected by the reflection mirror 5-1 and the concave mirror 5-2, and illuminates the light modulation element 5-3.
The red light LR emitted from the red light source 2-1 is collected by the condensing element 3-2, reflected by the dichroic mirror 4-2, and relayed by the condensing elements 3-4 and 3-5 to generate an image. Incident on the part 5. Thereafter, the red light LR is reflected by the reflection mirror 5-1 and the concave mirror 5-2, and illuminates the light modulation element 5-3.
The lighting timing of each light source 10, 2-1, 2-2 is as follows. Under the control of the control unit 7, the lighting drive unit 8 outputs the green light LG, the red light LR, and the blue light LB from the illumination device 1A, the red light source 2-1, and the blue light source 2-2 within one frame period of the image. The light is sequentially switched in a time division manner. Each micromirror of the light modulation element 5-3 is individually driven in synchronization with the timing of emission of the illumination light of each color. With this control, the projector 100 causes the projection optical system 6 to sequentially project the projection images of the respective colors based on the image generation data onto the screen Sc. Through the above operation, the projector 100 generates a full-color image based on the image generation data on the screen Sc using the afterimage phenomenon of the eyes.
As described above, in the tenth embodiment, by using the illumination devices 1 and 1A to 1G of the first to eighth embodiments, illumination light can be obtained more efficiently and a brighter projector 100 can be provided. it can. In the tenth embodiment, since the phosphor layer 19 that generates green fluorescence LF with high visibility is used as the wavelength conversion member of the illumination device 1A, a brighter projector 100 can be provided.
Next, an image projection apparatus according to an eleventh embodiment of the present invention will be described with reference to FIG. FIG. 12 is an optical diagram of a projector 100A as an image projection apparatus according to the eleventh embodiment. The projector 100A according to the eleventh embodiment is characterized in that three-plate liquid crystal panels 5A, 5B, and 5C are used as the image generation unit.
As shown in FIG. 12, a projector 100A according to the eleventh embodiment includes an illumination device 1A, a red light source 2-1 as a second light source (illumination device), and a blue light source 2- as a third light source (illumination device). 2, condensing elements 3-1, 3-2, 3-3, 3-4, 3-5, 3-6 as a relay optical system, and liquid crystal panels 5A, 5B, 5C as an image generating unit, A cross dichroic prism 4A, a projection optical system 6, a control unit 7, a lighting drive unit 8, and the like are configured.
The liquid crystal panels 5 </ b> A, 5 </ b> B, and 5 </ b> C are ON / OFF controlled by the control unit 7 based on the image information acquired from the image information source (storage unit) 9. The control unit 7 controls the lighting drive unit 8 to control the lighting of the light sources 10, 2-1, and 2-2 in response to the ON / OFF of the liquid crystal panels 5A, 5B, and 5C.
In the eleventh embodiment, the same lighting device 1A as in the second embodiment is used, but the lighting devices 1, 1B to 1G in the first, third to eighth embodiments can also be used.
In projector 100A having the above-described configuration, green light LG emitted from lighting apparatus 1A is relayed by condensing elements 3-1, 3-2 to illuminate liquid crystal panel 5A. The red light LR emitted from the red light source 2-1 is collected by the condensing elements 3-3 and 3-4 and illuminates the liquid crystal panel 5B. The blue light LB emitted from the blue light source 2-2 is collected by the light collecting elements 3-5 and 3-6, and illuminates the liquid crystal panel 5C.
The projection light of each color generated by each liquid crystal panel 5A, 5B, 5C is synthesized by the cross dichroic prism 4A by illumination of the illumination light of each color. The color image generated by the composition is enlarged and projected onto the screen Sc by the projection optical system 6.
As mentioned above, also in 11th Embodiment, illumination light can be obtained more efficiently by using the illuminating devices 1 and 1A-1G of the said 1st-8th embodiment. In addition, since the phosphor layer 19 that generates green fluorescence LF with high visibility is used, a brighter projector 100A can be provided. Further, the illumination device 1H of the ninth embodiment can also be used as the illumination device of the tenth and eleventh embodiments if the green phosphor is used as the phosphor 19H ′, and the illumination light can be used more efficiently. Can be obtained.
Next, an embodiment of an image projection apparatus according to a twelfth embodiment of the present invention will be described with reference to FIGS. FIG. 13 is an optical diagram of a projector 100B as an image projection apparatus according to the twelfth embodiment. FIG. 14 is a plan view of the color wheel 30 as a light separation member used in the projector 100B. The projector 100B according to the twelfth embodiment is characterized in that the illumination device 1H is provided with a color wheel 30 that extracts illumination light of different colors.
As shown in FIG. 13, a projector 100B according to the twelfth embodiment includes an illuminating device 1H, a blue light source 2-2 as a second light source (illuminating device), and condensing elements 3-1 and 3 as relay optical systems. -2, 3-3, 3-5, a dichroic mirror 4-1, a color wheel 30 as a wavelength separation unit, and an image generation unit 5 having a light modulation element 5-3 as a light valve (light valve); The projection optical system 6, the control unit 7, and the lighting drive unit 8 are configured. The lighting drive unit 8 includes an excitation light lighting drive unit 8-1 and a blue light source drive unit 8-2.
In the projector 100B according to the twelfth embodiment, the illumination light obtained sequentially from the illumination device 1H is applied to one panel (light modulation element 5-3) on which images corresponding to red R, green G, and blue B are formed. This is an image projection apparatus that illuminates and projects an image formed on the panel on the screen Sc by the projection optical system 6 in an enlarged manner.
The blue light source 2-2 uses an LED that generates blue component laser light, but an LD can also be used.
The color wheel 30 is disposed on the optical path of the fluorescence LF from the illumination device 1H and in the vicinity of the condensing position when the fluorescence LF is condensed by the condensing element 3-2. The color wheel 30 is rotationally controlled by the control unit 7 and is configured such that the spectral transmittance is switched in a time division manner on the optical path.
The color wheel 30 is formed by arranging a plurality of areas composed of fan-shaped color filters. The color wheel 30 preferably includes at least a first region that mainly transmits light in the red R wavelength band and a second region that mainly transmits light in the green G wavelength band. Furthermore, a third region that transmits light in the yellow Y wavelength band may be provided.
The color wheel 30 of the present embodiment includes a first wavelength separation unit 30a that transmits light in the red R wavelength band (red light LR) as the first region, and light in the green G wavelength band as the second region. A second wavelength separation unit 30b that transmits (green light LG) and a third wavelength separation unit 30c that transmits light in the wavelength band of yellow Y (yellow light LY) as a third region; It is configured. Further, the color wheel 30 of the present embodiment is provided with a transparent region 30d. The period in which the transparent region 30d is disposed on the optical path is a period in which the blue light LB from the blue light source 2-2 passes through the transparent region 30d.
In projector 100B configured as described above, yellow fluorescent light LF is obtained from lighting device 1H. The fluorescence LF output from the exit surface of the illumination device 1H becomes parallel light by the light condensing element 3-1, passes through the dichroic mirror 4-1, and then is condensed by the light condensing element 3-2. The light enters the color wheel 30 disposed in the vicinity. The color wheel 30 is rotationally controlled in conjunction with the excitation light lighting drive unit 8-1, so that the first, second, and third wavelength separation units 30a, 30b, and 30c are switched in a time division manner. Accordingly, red R, green G, and yellow Y light (red light LR, green light LG, and yellow light LY) can be sequentially extracted from the yellow fluorescence LF.
On the other hand, the blue light source 2-2, which is different from the light source 10H as the excitation light source, is driven by the blue light source driving unit 8-2 to emit the blue light LB, and the dichroic mirror 4- through the condensing element 3-3. Lead to one. The optical path of the blue light source 2-2 is combined with the optical path of the fluorescence LF, and the blue light LB enters the color wheel 30 via the light condensing element 3-2. At this time, since the transparent region 30d of the color wheel 30 is located in the optical path, the blue light LB is extracted by transmitting the blue light LB through the transparent region 30d.
As described above, by performing the light emission of the light source 10H of the excitation light, the light emission of the blue light source 2-2, and the rotation synchronization of the color wheel 30, at least red R, green G, and blue B from the light condensing element 3-5. Light can be extracted. In the present embodiment, since the third wavelength separation unit 30c that transmits light in the yellow Y wavelength band is also added, four colors of single color light (red light LR, green light LG, yellow light LY, blue light LB) are included. ) In time order.
An image is generated by irradiating this illumination light to a light modulation element 5-3 such as DMD, and the image is enlarged by the projection optical system 6 and enlarged and projected onto the screen Sc. Also in this case, the control unit 7 cooperates with the rotation synchronization of the excitation light lighting drive unit 8-1, the blue light source drive unit 8-2, and the color wheel 30, and based on the input image information, the light modulation element 5- 3 is controlled.
In the twelfth embodiment, the illumination device 1H of the ninth embodiment is used. However, the illumination devices 1 and 1A to 1G of the first to eighth embodiments also use a yellow phosphor for the phosphor layer. Then, it can also be used as the illumination device of the twelfth embodiment.
As described above, also in the twelfth embodiment, by using the illumination devices 1 and 1A to 1H of the first to ninth embodiments, it is possible to provide a brighter projector 100B that can obtain illumination light more efficiently. it can. In the twelfth embodiment, high-luminance red illumination light can be obtained by using the yellow phosphor and extracting the red light LR from the yellow fluorescence LF by the color wheel 30. Further, since the color wheel 30 is rotated and the first, second, and third wavelength separation units 30a, 30b, and 30c are switched in a time-sharing manner to extract light of each color, illumination that can obtain bright monochromatic light is obtained. The apparatus and the projector 100B can be realized.
As mentioned above, although the illuminating device and image projection apparatus of this invention have been demonstrated based on each embodiment, it is not limited to each embodiment about a concrete structure, Unless it deviates from the summary of this invention, it is a design change. Or additions are allowed. Further, the number, position, shape, and the like of the constituent members are not limited to each embodiment, and can be set to a number, position, shape, and the like that are suitable for carrying out the present invention. In each of the above-described embodiments, the example in which the image projection apparatus is applied to an image projection apparatus (projector) that projects and displays an image on a projection surface such as a screen has been described. However, the present invention is limited to these embodiments. It will never be done. For example, the present invention can be applied to an image projection apparatus or the like as an exposure apparatus that exposes a circuit pattern on a wafer in a semiconductor device production process.
1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H Illumination device 5 Image generator 5-3 Light modulation element (light valve) 5A, 5B, 5C Liquid crystal panel (image generator)
6 Projection optical system 10, 10H Light source 10E Light source (excitation light source, incident part)
13 Condensing optical system (incident part) 13H Light diffusion member (incident part)
14, 14A, 14B, 14C, 14D, 14E, 14F, 14G, 14H Light tunnel (light guide member)
15, 15D, 15E Light entrance opening (light entrance) 15H Light entrance 16 Light exit opening (light exit) 16H Light exit 17 Light guide path 19, 19B, 19D, 19E Phosphor layer (wavelength conversion member) )
19H 'phosphor (wavelength conversion member) 21 wavelength selection element (wavelength selection unit)
21D, 21E Wavelength selection film (wavelength selection section) 21H Color selection filter (wavelength selection section)
22 wavelength selection element (second wavelength selection unit) 23 heat sink (heat dissipation structure)
30 Color wheel (wavelength separation unit) 100, 100A, 100B Projector
JP 2006-214006 A Japanese Patent No. 5510828
A light source that generates light of a predetermined wavelength band;
A light incident part into which light is incident, a light emitting part from which light is emitted, and a light guide member having a light guide path extending from the light incident part to the light emitting part,
The light guide member includes therein a wavelength conversion member that generates light that has been wavelength-converted into a wavelength band different from the light from the light source,
The illuminating device according to claim 1, wherein the light incident portion includes a wavelength selection portion that transmits light from the light source and reflects the wavelength-converted light.
An incident portion is provided between the light source and the light guide member so that light from the light source diverges in the vicinity of the light incident portion and is incident on the light guide member so as to be irradiated to the wavelength conversion member. The lighting device according to claim 1.
3. The illumination device according to claim 1, wherein the light guide member has a tapered structure in which the diameter on the light incident part side is the smallest and the diameter gradually increases toward the light emitting part. 4. .
The illuminating device according to claim 1, wherein the light incident portion is provided in a position near an end portion on an incident side of the excitation light and facing the wavelength conversion member. .
5. The illumination according to claim 1, wherein a second wavelength selection unit that transmits the wavelength-converted light and reflects the excitation light is disposed in the light emitting unit. apparatus.
The lighting device according to any one of claims 1 to 5, wherein the light guide member has an inner surface provided with at least the wavelength conversion member formed of a member having thermal conductivity.
The lighting device according to claim 1, wherein the light guide member is provided with a heat dissipation structure on an outer surface opposite to an inner surface on which the wavelength conversion member is provided. .
The illuminating device according to any one of claims 1 to 7, wherein a phosphor that is excited by the excitation light and generates fluorescence including at least green is provided as the wavelength conversion member.
The illumination apparatus according to claim 1, wherein a wavelength selection unit that selectively takes out the wavelength-converted light and guides the light in the direction of the light emission unit is disposed in the light incident unit.
The illumination device according to claim 9, wherein the wavelength selection unit transmits light from the light source, reflects the wavelength-converted light, and guides the light in a direction toward the light emitting unit.
The illumination device according to any one of claims 1 to 10, wherein the wavelength conversion member is a wavelength conversion member that emits fluorescence including at least a red component and a green component.
The illumination device according to claim 11, further comprising a wavelength separation unit that separates the fluorescence into red illumination light including a red wavelength band and green illumination light including a green wavelength band.
The wavelength separation unit includes at least a first wavelength separation unit that selectively extracts green illumination light including a green wavelength band and a second wavelength separation unit that selectively extracts red illumination light including a red wavelength band. It is comprised by two or more area | regions, This 1st wavelength separation part and this 2nd wavelength separation part are comprised so that the optical path of the said fluorescence may be replaced | exchanged time-sequentially. The lighting device described.
14. A lighting device according to claim 13, a single light valve that is illuminated with at least two colors of illumination light obtained in time sequence from the lighting device, and displays a modulated image corresponding to each color, and the light An image projection apparatus comprising: a projection optical system that projects the image obtained by the bulb.
JP2015120888A 2015-02-20 2015-06-16 Illumination device and image projection device Pending JP2016157096A (en)
JP2015031828 2015-02-20
EP16752096.4A EP3259644A4 (en) 2015-02-20 2016-02-09 Illumination device and image projection apparatus
CN201680010326.XA CN107250909A (en) 2015-02-20 2016-02-09 Lighting device and image projecting equipment
US15/547,901 US10423055B2 (en) 2015-02-20 2016-02-09 Illumination device and image projection apparatus
PCT/JP2016/000652 WO2016132706A1 (en) 2015-02-20 2016-02-09 Illumination device and image projection apparatus
JP2016157096A true JP2016157096A (en) 2016-09-01
ID=56825963
JP2015120888A Pending JP2016157096A (en) 2015-02-20 2015-06-16 Illumination device and image projection device
US (1) US10423055B2 (en)
EP (1) EP3259644A4 (en)
JP (1) JP2016157096A (en)
CN (1) CN107250909A (en)
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2016-02-09 EP EP16752096.4A patent/EP3259644A4/en active Pending
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