JP6279516B2 - Light source device and image projection device - Google Patents

Description

  The present invention relates to a light source device and an image projecting device, and more particularly to a light source device used as a light source of a projection type image display device (image projecting device) such as a projector and an image projecting device including the same.

  In recent years, opportunities for using a projection type image display device such as a projector have increased in appreciation of movies at home and presentations at conferences. In such a projector, a discharge lamp such as a high-intensity mercury lamp is generally used as a light source. A projector using a solid-state light-emitting element has also been proposed with the progress of development technology of recent solid-state light-emitting elements (for example, semiconductor lasers, light-emitting diodes) (see, for example, Patent Document 1).

  The projector proposed in Patent Document 1 is a DLP (Digital Light Processing: registered trademark) type projector. This type of projector displays images in full color by displaying light of different colors in a time-sharing manner several thousand times per second.

  The projector disclosed in Patent Document 1 includes a light emitting diode (excitation light source) that emits blue light (excitation light), a transparent base material provided on the emission side of excitation light, and a surface orthogonal to the emission direction of excitation light. A light source device including a motor that rotates inside.

  In the light source device of Patent Document 1, a red phosphor layer that emits red light when irradiated with excitation light, a green phosphor layer that emits green light when irradiated with excitation light, and excitation light on a transparent substrate. The regions to be passed through are formed in different regions. Therefore, in the projector of Patent Document 1, when excitation light is irradiated onto a transparent substrate that rotates at a predetermined rotation speed, blue light (excitation light), red light and green light excited by the excitation light are time-divisionally light sources. Injected from the device.

JP 2009-277516 A

  As described above, a projector that does not use a mercury lamp has been conventionally proposed. With such a projector, a mercury-free projector can be realized, and it is possible to cope with recent environmental problems. Further, when a solid-state light emitting element such as a semiconductor laser or a light emitting diode is used as a light source, there are advantages that it has a longer life than a mercury lamp and a decrease in luminance is small.

  However, the technique proposed in Patent Document 1 is applied only to a light source device (illumination device) that emits a plurality of monochromatic lights having different wavelengths in a time-division manner, such as a DLP (registered trademark) projector. Is possible. For example, it cannot be applied to an application that requires a light source device that emits white light, such as an image display device such as a 3LCD (Liquid Crystal Display) projector.

  The present invention has been made in view of the above situation, and an object of the present invention is to provide a mercury-less light source device that can be applied to various uses such as a 3LCD projector, and an image projection device including the mercury-free light source device. Is to provide.

In order to solve the above-described problems, a light source device of the present invention includes a laser light source, a single fluorescent member, and a drive unit, and functions of each unit are as follows. The laser light source emits excitation light having a peak wavelength in a first wavelength band including blue light . The single fluorescent member has a peak wavelength in a second wavelength band including green light and red light that is different from the first wavelength band when irradiated with excitation light and a substrate that can rotate around a rotation axis. A phosphor having a single emission characteristic, which is continuously formed on one side of the substrate along the rotational circumferential direction of the substrate, and formed on the other side of the substrate and excited. And an antireflection film for preventing reflection of light. The drive unit has a drive shaft connected to the center of the substrate, and rotates the fluorescent member so that the irradiation position of the excitation light applied to the phosphor moves in the rotational circumferential direction with time. The phosphor has a peak wavelength in the second wavelength band while the driving unit rotates the phosphor member in a predetermined direction and the excitation light is irradiated on the phosphor over one rotation in the circumferential direction. The fluorescent member emits emitted light, and the fluorescent member combines and emits a part of the excitation light and the emitted light . The “wavelength” here means not only a single wavelength but also a predetermined wavelength band.

  Moreover, the image projector of this invention is set as the structure provided with a light source device part and an image projector, and the function of each part is as follows. The light source device section has the same configuration as the light source device of the present invention. The image projection unit generates predetermined image light using the light emitted from the light source device unit, and projects the generated image light to the outside.

In the present invention, a phosphor having a single light emission characteristic that is continuously formed along the circumferential direction is irradiated with excitation light, whereby the excitation light wavelength band (first wavelength band) and Emits light having a different wavelength band (second wavelength band), transmits part of the excitation light, transmits the transmitted excitation light, and light emitted from the phosphor (hereinafter referred to as emission light). Are combined and ejected. That is, in the present invention, light having a wavelength band different from the excitation light and the emitted light is emitted from the phosphor. Therefore, in the present invention, for example, when the excitation light is blue light and the emitted light is light including both components of red light and green light (for example, yellow light), white light is emitted from the phosphor. be able to.

  As described above, in the present invention, for example, white light or the like is emitted from the phosphor by appropriately setting a combination of excitation light having the first wavelength band and emission light having the second wavelength band. Can do. Further, by providing the antireflection film, reflection of excitation light generated before entering the fluorescent member can be prevented. Further, the excitation light source irradiates the phosphor with the excitation light in a state where the drive unit rotates the fluorescent member in a predetermined direction in the irradiation surface of the excitation light of the phosphor. In this case, phosphor atoms that are not excited are arranged one after another, and the phosphor can emit light more efficiently. Moreover, since the irradiation position of the excitation light applied to the phosphor changes, white light having the same spectrum in time can be stably generated while preventing the temperature of the phosphor from rising. According to the present invention, it is possible to provide a mercury-free light source device that can be applied to various uses such as a 3LCD projector, and an image projection device including the same.

1 is a schematic block configuration diagram of an image display device according to an embodiment of the present invention. It is a schematic block diagram of the fluorescent member used for the light source device part (illuminating device) which concerns on one Embodiment of this invention. It is a figure which shows the example of 1 structure of the reflecting film used with a fluorescent member. It is a figure which shows the relationship between the transmittance | permeability of the reflective film used with a fluorescent member, and a light incident angle. It is a figure which shows the mode of the light emission in a fluorescent substance, and the mode of the light reflection in the reflective film surface. It is the spectrum characteristic of the emitted light of the light source device part (illuminating device) which concerns on one Embodiment of this invention.

Hereinafter, an example of an illumination device according to an embodiment of the present invention and an image display device including the illumination device will be described in the following order with reference to the drawings. In the present embodiment, a 3LCD projector (image projection apparatus) will be described as an example of the image display apparatus, but the present invention is not limited to this.
1. 1. Configuration example of image display device 2. Configuration example of light source device section (illumination device) 3. Configuration example of fluorescent member Example of operation of light source unit

[1. Configuration example of image display apparatus]
FIG. 1 shows a schematic configuration of an image display apparatus according to an embodiment of the present invention. In FIG. 1, for the sake of simplification of description, only main parts that operate when image light is projected to the outside in the image display apparatus 10 of the present embodiment are mainly shown. FIG. 1 shows a configuration example of a 3LCD type projector using a transmissive LCD light modulation element, but the present invention is not limited to this. The present invention can also be applied to a 3LCD projector using a reflective LCD light modulation element.

  The image display device 10 includes a light source device unit 1 (illumination device) and an optical engine unit 2 (image projection unit). The configuration of the light source device unit 1 will be described in detail later.

  The optical engine unit 2 optically processes light emitted from the light source device unit 1 (in this example, white light LW) to generate image light LI, and enlarges and projects the image light LI onto an external screen, for example, To do. The optical engine unit 2 includes, for example, a spectroscopic optical system 20, three LCD light modulation elements (hereinafter referred to as a first LCD panel 21 to a third LCD panel 23, respectively), a prism 24, and a projection optical system 25. In addition, the structure of the optical engine part 2 is not limited to the example shown in FIG. 1, For example, it can change suitably according to a use etc. For example, various optical elements necessary for the optical path between the parts may be appropriately arranged.

  Moreover, in the optical engine part 2 of this example, both are arrange | positioned so that the light-projection surface of the 1st LCD panel 21 and the light-projection surface of the 3rd LCD panel 23 may oppose, and it is in the direction orthogonal to the opposing direction of both. A second LCD panel 22 is arranged. Then, the prism 24 is disposed in a region surrounded by the light emission surfaces of the first LCD panel 21 to the third LCD panel 23. In this example, the projection optical system 25 is disposed at a position facing the light emitting surface of the second LCD panel 22 with the prism 24 interposed therebetween. The spectroscopic optical system 20 is provided on the light incident side of the first LCD panel 21 to the third LCD panel 23.

  The spectroscopic optical system 20 includes, for example, a dichroic mirror, a reflection mirror, and the like, and splits the white light LW incident from the light source device unit 1 into the blue light LB, the green light LG, and the red light LR, and the light of each wavelength component. To the corresponding LCD panel. In this example, the spectroscopic optical system 20 emits the split blue light LB, green light LG, and red light LR to the first LCD panel 21, the second LCD panel 22, and the third LCD panel 23, respectively.

  Each of the first LCD panel 21 to the third LCD panel 23 is composed of a transmissive LCD panel. Each LCD panel changes the arrangement of liquid crystal molecules sealed in a liquid crystal cell (not shown) based on a drive signal from a panel drive unit (not shown), thereby transmitting or blocking incident light in units of liquid crystal cells ( Modulate). Each LCD panel emits modulated light having a predetermined wavelength (modulated light) to the prism 24.

  The prism 24 combines the modulated light of each wavelength component incident from the first LCD panel 21 to the third LCD panel 23 and emits the combined light, that is, the image light LI to the projection optical system 25.

  The projection optical system 25 enlarges and projects the image light incident from the prism 24 onto a display surface such as an external screen.

[2. Configuration example of light source device unit 1]
Next, the internal configuration of the light source device unit 1 of the present embodiment will be described with reference to FIG.

  The light source unit 1 includes an excitation light source 11, a first condensing optical system 12 (first optical system), a fluorescent member 13, a motor 14 (driving unit), and a second condensing optical system 15 (second optical). System). And in the light source device part 1 of this embodiment, the 1st condensing optical system 12, the fluorescent member 13, and the 2nd condensing optical system 15 are arrange | positioned in this order from the exit opening side of the excitation light L of the excitation light source 11. Is done. At this time, the first condensing optical system 12, a layered phosphor 32 (hereinafter referred to as a phosphor layer 32) in the fluorescent member 13, and the second condensing optical system 15 are on the optical path of the excitation light L. Place it so that it is located in

  The excitation light source 11 is composed of a solid light emitting element that emits light of a predetermined wavelength (first wavelength). In this example, a blue laser that emits blue light having a wavelength of 445 nm is used as the excitation light source 11. In the present embodiment, the wavelength of the excitation light L incident on the phosphor layer 32 is made shorter than the wavelength of the emitted light in the phosphor layer 32 described later in the phosphor member 13.

  Further, when a blue laser is used as the excitation light source 11, a configuration in which the excitation light L having a predetermined output is obtained with one blue laser may be used. However, the light emitted from a plurality of blue lasers may be combined to be excited with a predetermined output. The light L may be obtained. Furthermore, the wavelength of blue light (excitation light L) is not limited to 445 nm, and any wavelength can be used as long as it is within the wavelength band of light called blue light.

  The first condensing optical system 12 condenses the excitation light L emitted from the excitation light source 11 and emits the condensed excitation light L (hereinafter referred to as “condensed light”) to the fluorescent member 13. At this time, parameters such as a lens configuration, a focal length, and an arrangement position of the first condensing optical system 12 are designed so that the condensed light is incident on the fluorescent member 13 at a predetermined incident angle θ. Moreover, the incident angle θ of the condensed light is appropriately set according to, for example, the transmission characteristics (reflection angle dependency of the transmittance) of the reflection film 31 described later in the fluorescent member 13.

  Note that when the spot diameter of the excitation light L is reduced by the first condensing optical system 12, the fluorescent member 13 can be irradiated with the excitation light L having a high light density. However, if the spot of the excitation light L is too narrow, the excitation light L having a light amount larger than the light amount necessary for causing the phosphor atoms in the irradiation region to emit light is irradiated. In this case, the amount of light that does not contribute to the light emission of the phosphor atoms in the irradiation region increases, so the ratio of the light emission amount to the amount of incident excitation light L decreases, and the light emission efficiency of the phosphor layer 32 decreases. Therefore, in the present embodiment, the configuration of the first condensing optical system 12 is designed so that the spot diameter of the condensed light is a diameter that does not decrease the light emission efficiency.

  Conversely, if the spot diameter of the condensed light is too wide, the spread of the emitted light from the fluorescent member 13 increases. In this case, the first condensing optical system 12 may be adjusted so that the spot diameter of the condensed light does not spread too much, or the light emitted by the second condensing optical system 15 may be adjusted to a predetermined diameter. It may be configured to convert the light into parallel light.

  The fluorescent member 13 emits light of a predetermined wavelength band (second wavelength) by the excitation light L (blue light) incident through the first condensing optical system 12, and a part of the excitation light L is emitted. Make it transparent. In this example, since the light incident on the optical engine unit 2 is white light LW, the fluorescent member 13 emits light in a wavelength band (about 480 to 680 nm) including green light and red light by the excitation light L. . In this embodiment, the white light LW is generated by combining the emission light in the wavelength band including the green light and the red light and a part of the excitation light L (blue light) transmitted through the fluorescent member 13. A more detailed configuration of the fluorescent member 13 will be described later.

  The motor 14 rotationally drives the fluorescent member 13 at a predetermined rotational speed. At this time, the motor 14 drives the fluorescent member 13 so that the fluorescent member 13 rotates in a direction along a surface orthogonal to the irradiation direction of the excitation light L (an irradiation surface of the phosphor layer 32 to be described later). To do.

  The rotating shaft 14a of the motor 14 is attached to the center of a transparent substrate 30 (to be described later) of the fluorescent member 13, and the transparent substrate 30 is fixed to the rotating shaft 14a by a fixing hub 14b. Then, the fluorescent member 13 is rotationally driven by the motor 14 so that the irradiation position of the excitation light L in the fluorescent member 13 is temporally at a speed corresponding to the number of rotations in a plane orthogonal to the irradiation direction of the excitation light L. Moving.

  As described above, the fluorescent member 13 is rotationally driven by the motor 14 and the irradiation position of the excitation light L in the fluorescent member 13 is moved with time, whereby the temperature rise of the irradiation position can be suppressed, and the phosphor layer 32. It is possible to prevent a decrease in luminous efficiency. Further, it takes some time (for example, about several nsec) until the phosphor atoms absorb the excitation light L and emit light, and even if the next excitation light L is irradiated to the phosphor atoms during the excitation period, the excitation is performed. The light L is not emitted. However, by moving the irradiation position of the excitation light L in the fluorescent member 13 with time as in the present embodiment, phosphor atoms that are not excited are successively arranged at the irradiation position of the excitation light L. Thus, the phosphor layer 32 can emit light more efficiently.

  In this embodiment, an example in which the fluorescent member 13 is rotationally driven by the motor 14 is shown. However, the present invention is not limited to this, and the irradiation position of the excitation light L in the fluorescent member 13 may move with time. Any configuration can be used. For example, the excitation light L is reciprocated linearly in a predetermined direction in a plane orthogonal to the irradiation direction of the excitation light L (in the irradiation surface of the excitation light L of the phosphor layer 32 described later). The irradiation position may be moved with time. Alternatively, the irradiation position of the excitation light L may be moved with time by fixing the fluorescent member 13 and moving the excitation light source 11 relative to the fluorescent member 13.

  The second condensing optical system 15 condenses the light emitted from the fluorescent member 13 (white light LW) and converts it into parallel light. The second condensing optical system 15 guides the parallel light to the spectroscopic optical system 20 of the optical engine unit 2. Note that the second condensing optical system 15 may be configured by a single collimating lens, or may be configured to convert incident light into parallel light using a plurality of lenses. Further, since the emitted light from the fluorescent member 13 is light that spreads in a Lambertian (uniform diffusion) shape, the second condensing optical system 15 and the fluorescent member 13 (more specifically, a phosphor layer 32 described later) are used. It is preferable to make the distance between them as short as possible.

  In the present embodiment, the example in which the first condensing optical system 12 and the second condensing optical system 15 are provided in the light source device unit 1 has been described, but the present invention is not limited to this. For example, when the light source device unit 1 of the present embodiment is applied to an application where there is no problem even if the output light from the light source device unit 1 is small, the first condensing optical system 12 and the second condensing optical system are used. You may make it the structure which does not have any one or both of the systems 15.

[3. Configuration example of fluorescent member]
Next, a more detailed configuration of the fluorescent member 13 will be described with reference to FIGS. 2A is a front view of the fluorescent member 13 viewed from the second condensing optical system 15 side, and FIG. 2B is a cross-sectional view taken along line AA in FIG. 2A. FIG. 2C is a front view of the fluorescent member 13 viewed from the first condensing optical system 12 side.

  The fluorescent member 13 is formed on the disk-shaped transparent substrate 30, the reflective film 31 and the phosphor layer 32 (phosphor) formed on one surface of the transparent substrate 30, and the other surface of the transparent substrate 30. And an antireflection film 33.

  The transparent substrate 30 is made of a transparent material such as glass or transparent resin. The size such as the thickness of the transparent substrate 30 is appropriately set in consideration of, for example, necessary transmittance and strength.

  The reflective film 31 is formed in a donut shape on one surface of the transparent substrate 30 as shown in FIG. The reflective film 31 is disposed on the transparent substrate 30 so that the donut-shaped reflective film 31 and the transparent substrate 30 are concentric. Note that the radial width of the reflective film 31 is set to be larger than the spot size of the excitation light L (condensed light) collected by the first condensing optical system 12.

  The reflective film 31 not only reflects the light (emitted light) excited by the phosphor layer 32 to the second light collecting optical system 15 side but also the excitation light L scattered and reflected in the phosphor layer 32. (Blue light) is also reflected to the second condensing optical system 15 side.

  Here, FIG. 3 shows a configuration example of the reflective film 31. The reflective film 31 is formed by alternately laminating a first dielectric layer 31a made of, for example, an SiO2 layer or an MgF2 layer and a second dielectric layer 31b made of, for example, a TiO2 layer or a Ta2O3 layer on the transparent substrate 30. Formed. That is, the reflective film 31 can be formed of a dichroic mirror (dichroic film). In addition, the number of laminated layers of the first dielectric layer 31a and the second dielectric layer 31b is usually several to several tens. Further, the first dielectric layer 31a and the second dielectric layer 31b are formed using a lamination method such as a vapor deposition method or a sputtering method.

  When the reflective film 31 is configured by a dichroic mirror as shown in FIG. 3, for example, by adjusting the number of dielectric layers stacked, the thickness of each dielectric layer, the formation material of each dielectric layer, etc. It becomes easy to set the incident angle dependency of the transmittance (reflectance) of light incident on the reflective film 31. FIG. 4 shows an example of the incident angle dependence of the light transmittance of the reflective film 31 used in this embodiment. The horizontal axis of the characteristic shown in FIG. 4 is the wavelength of incident light, and the vertical axis is the transmittance.

  In the example shown in FIG. 4, the reflective film 31 is designed to selectively reflect light in a wavelength band (wavelength region extending over about 480 to 680 nm) including red light and green light regardless of the incident angle θ. Has been. Therefore, the transmittance of the light in the wavelength band including the red light and the green light (the light emitted from the phosphor layer 32) is substantially zero regardless of the incident angle θ of the light. That is, the light in the wavelength region including red light and green light is all reflected by the reflective film 31 regardless of the incident angle θ.

  On the other hand, for blue light (excitation light L) having a wavelength of 445 nm, blue light is transmitted when the incident angle θ is approximately 20 degrees or less, and blue light is transmitted when the incident angle θ is greater than approximately 20 degrees. The reflective film 31 is designed so that is reflected. Therefore, as shown in FIG. 4, at a wavelength of 445 nm (thick broken line) of blue light (excitation light L), when the incident angle θ of light is 0 degrees (solid line) and 15 degrees (broken line), the transmittance is growing. Further, when the incident angle θ of blue light is 30 degrees (dashed line), 45 degrees (dotted line), and 60 degrees (dashed line), the transmittance at a wavelength of 445 nm is small. That is, of the excitation light L scattered and reflected in the phosphor layer 32, the excitation light component incident on the reflection film 31 at an incident angle θ greater than about 20 degrees is reflected by the second light collection optical system 15 at the reflection film 31. Reflected in the direction toward.

  Note that, as described above, the configuration of the first condensing optical system 12 is designed according to the incident angle dependency of the transmittance of the reflective film 31. For example, when the reflection film 31 has the incident angle dependency of the transmittance as shown in FIG. 4, the incident angle θ of the condensed excitation light L is set so as not to reduce the utilization efficiency of the excitation light L. The first condensing optical system 12 is designed to be about 20 degrees or less.

  The phosphor layer 32 is a layered phosphor that emits light in a predetermined wavelength band when the excitation light L enters. In the present embodiment, the transmitted light of the excitation light L and the light emitted from the phosphor layer 32 are combined to generate white light LW. As the phosphor layer 32, for example, YAG (Yttrium Aluminum Garnet) fluorescence It is made of materials. In this case, when the blue excitation light L is incident, the phosphor layer 32 emits light having a wavelength of 480 to 680 nm (yellow light). The phosphor layer 32 can be made of any material as long as it is a film that emits light in a wavelength band including red light and green light. However, in terms of light emission efficiency and heat resistance, YAG-based fluorescence can be used. It is preferable to use a body material.

  The phosphor layer 32 is formed by applying a predetermined fluorescent agent mixed with a fluorescent material and a binder on the reflective film 31. In the example shown in FIGS. 2A to 2C, since the phosphor layer 32 is formed over the entire surface of the reflective film 31, the surface shape of the phosphor layer 32 is also a donut shape. In addition, since the fluorescent substance layer 32 should just be formed in the area | region where the excitation light L injects, the shape of the fluorescent substance layer 32 is not limited to the example shown to Fig.2 (a)-(c), For example, the radial width of the phosphor layer 32 may be narrower than that of the reflective film 31.

  Further, the light emission amount and the transmission amount of the excitation light L in the phosphor layer 32 can be adjusted by, for example, the thickness of the phosphor layer 32, the phosphor density (content), or the like. Therefore, in the present embodiment, the thickness of the phosphor layer 32, the phosphor density, and the like are adjusted so that the emitted light from the light source device unit 1 becomes white light.

  The antireflection film 33 is provided on the surface on the incident side of the excitation light L of the transparent substrate 30, and reflects the excitation light L generated on the incident surface when the condensed light of the excitation light L is incident on the fluorescent member 13. To prevent. Thereby, the utilization efficiency of the excitation light L can be improved.

  In the above embodiment, the example in which the reflective film 31 and the antireflection film 33 are provided on the fluorescent member 13 has been described. However, the present invention is not limited to this. For example, when the light source device unit 1 according to the present embodiment is applied to an application where there is no problem even if the output light from the light source device unit 1 is small, either one of the reflective film 31 and the antireflection film 33 or You may make it the structure which does not have both. Furthermore, although the example which provides the layered fluorescent substance (phosphor layer 32) via the reflecting film 31 on the transparent substrate 30 was demonstrated in the fluorescent member 13 of the said embodiment, this invention is not limited to this. For example, when the phosphor is formed of a plate member having sufficient rigidity, the transparent substrate 30 may not be provided.

[4. Example of operation of light source unit]
FIG. 5 shows the operation of the light source device unit 1 of the present embodiment. In the light source device unit 1 of the present embodiment, first, the excitation light L (blue light in this example) emitted from the excitation light source 11 is condensed by the first condensing optical system 12. Then, the condensed light (the condensed excitation light L) is incident on the fluorescent member 13 at a predetermined incident angle θ from the antireflection film 33 side of the fluorescent member 13. In this embodiment, the fluorescent light 13 is irradiated to the fluorescent member 13 by the motor 14 in a state where the fluorescent member 13 is rotated at a predetermined rotational speed.

  The condensed light incident on the fluorescent member 13 passes through the antireflection film 33, the transparent substrate 30, and the reflective film 31 and is incident on the phosphor layer 32. As described above, since the reflection film 31 is designed to transmit the excitation light L having a predetermined incident angle θ or less, the condensed light incident on the fluorescent member 13 is reflected by the reflection film 31. Not.

  When condensed light (excitation light L) is incident on the phosphor layer 32, a part thereof passes through the phosphor layer 32, but the rest is mainly absorbed by the phosphor layer 32. The phosphor layer 32 is excited by the absorbed excitation light L, and light in a predetermined wavelength band (yellow light including red light and green light in this example) is emitted from the phosphor layer 32. As a result, the transmission component of the excitation light L and the emitted light from the phosphor layer 32 are combined, and white light is emitted from the phosphor layer 32.

  At this time, the light emitted from the phosphor layer 32 is emitted not only in the direction toward the second condensing optical system 15 but also in the direction toward the transparent substrate 30. A part of the excitation light L incident on the phosphor layer 32 is also scattered and reflected in the direction toward the transparent substrate 30 in the phosphor layer 32. However, in the fluorescent member 13 of the present embodiment, as described above, the reflective film 31 is provided between the transparent substrate 30 and the phosphor layer 32, so that the emitted light emitted in the direction toward the transparent substrate 30 and The excitation light component is reflected by the reflective film 31 in the direction toward the second condensing optical system 15. At this time, the excitation light component reflected by the reflective film 31 is absorbed by the phosphor layer 32 and further causes the phosphor layer 32 to emit light. Therefore, when the reflective film 31 is provided between the transparent substrate 30 and the phosphor layer 32 as in the present embodiment, the utilization efficiency of the excitation light L can be improved, and the amount of emitted light can be reduced. Can be increased.

Actually, the present inventor set the parameters of each part of the light source device unit 1 as follows, and examined the spectral characteristics of the emitted light from the light source device unit 1.
Wavelength of excitation light source 11 (blue laser): 445 nm
Condensing diameter of excitation light L: 1 mm
Incident angle θ of excitation light L: 20 degrees or less Number of rotations of fluorescent member 13: 3000 rpm
Distance between second condensing optical system 15 and phosphor layer 32: 1 mm or less Forming material of transparent substrate 30: Glass Diameter of transparent substrate 30: 30 mm
Transmission characteristics of the reflective film 31: characteristics shown in FIG. 4 Material for forming the phosphor layer 32: YAG-based phosphor Thickness of the phosphor layer 32: 50 μm
Width of phosphor layer 32: 5 mm

  FIG. 6 shows the spectral characteristics of the emitted light from the light source unit 1 obtained under the above conditions. In the characteristics shown in FIG. 6, the horizontal axis is the wavelength, and the vertical axis is the intensity (arbitrary unit) of the emitted light. As is apparent from FIG. 6, under the above conditions, the emitted light includes a light component in the vicinity of a wavelength of 445 nm (blue light component) and a light component in a wavelength region extending over about 480 to 680 nm, that is, a red light component and a green light component. It can be seen that a light component including This also shows that the white light LW is emitted from the light source device unit 1 of the present embodiment.

  As described above, in the present embodiment, white light can be emitted from the light source device unit 1 using a solid light emitting element. Therefore, the present embodiment can also be applied to applications that require a light source device that emits white light, such as a 3LCD projector. That is, in the present embodiment, it is possible to provide a mercury-less light source device unit 1 (illumination device) that can be applied to various uses and an image display device 10 including the same.

  Since the light source device unit 1 of this embodiment does not need to use a mercury lamp, it can cope with recent environmental problems. Further, in the present embodiment, it is possible to provide the light source device unit 1 and the image display device 10 that have a longer lifetime and a lower luminance reduction than the mercury lamp. Further, when a solid light emitting element is used as the excitation light source 11 as in the present embodiment, the lighting time can be further shortened as compared with a mercury lamp.

  Further, when a semiconductor laser is used as the excitation light source 11 as in the light source device unit 1 of the present embodiment, light with sufficiently high luminance is emitted even when compared with a solid light source such as an LED (Light Emitting Diode). Therefore, a high-intensity light source can be realized. Further, as in the present embodiment, the configuration in which the phosphor layer 32 is caused to emit light by the blue light laser to generate the white light LW is prepared by separately preparing solid light sources of red light, green light, and blue light separately. It is cheaper than the structure which produces | generates.

  In the above embodiment, the example in which the light source device unit 1 (illumination device) is applied to a 3LCD projector has been described, but the present invention is not limited to this, and can be applied to any image display device that requires white light. The same effect can be obtained.

  Moreover, although the said embodiment demonstrated the example which made the emitted light of the light source device part 1 (illuminating device) white light, this invention is not limited to this. For example, in applications that require cyan light (or magenta light) as the emitted light, blue light is used as the excitation light L, and the phosphor layer 32 is formed of a fluorescent material that emits only green light (or red light). Good. That is, a combination of the wavelength of the excitation light L and the material for forming the phosphor layer 32 may be appropriately selected according to the required wavelength (color) of the emitted light.

DESCRIPTION OF SYMBOLS 1 ... Light source device part (illuminating device), 2 ... Optical engine part (image projection part), 10 ... Image display apparatus, 11 ... Excitation light source, 12 ... 1st condensing optical system, 13 ... Fluorescent member, 14 ... Motor, DESCRIPTION OF SYMBOLS 15 ... 2nd condensing optical system, 20 ... Spectroscopic optical system, 21 ... 1st LCD panel, 22 ... 2nd LCD panel, 23 ... 3rd LCD panel, 24 ... Prism, 25 ... Projection optical system, 30 ... Transparent substrate, 31 ... Reflective film, 32 ... phosphor layer (phosphor), 33 ... antireflection film

Claims (13)

A laser light source that emits excitation light having a peak wavelength in a first wavelength band including blue light;
Emits emitted light having a peak wavelength in a second wavelength band including green light and red light different from the first wavelength band when irradiated with the excitation light and a substrate rotatable around a rotation axis. And a phosphor having a single light emission characteristic continuously formed on one side of the substrate along the circumferential direction of the substrate, and the excitation light formed on the other side of the substrate. A single fluorescent member having an antireflection film for preventing reflection of
A drive shaft connected to the center of the substrate, and a drive unit that rotates the fluorescent member so that an irradiation position of the excitation light irradiated to the phosphor moves in the rotation circumferential direction with time, and
While the driving unit rotates the fluorescent member in a predetermined direction, and the excitation light is irradiated on the fluorescent body over one circumference of the rotational circumferential direction, the fluorescent substance is in the second wavelength band. Emitting the emitted light having a peak wavelength at
The fluorescent member is a light source device that combines and emits a part of the excitation light and the emitted light. The light source device according to claim 1, further comprising a fixing hub that fixes the substrate to the drive shaft. A first optical system that condenses the excitation light so that the spot diameter of the excitation light irradiated onto the phosphor has a predetermined spot diameter;
The light source device according to claim 1, wherein the spot diameter is determined based on characteristics of the phosphor. The light source device according to claim 3, wherein the fluorescent member further includes a reflective film that transmits the excitation light and reflects the emitted light emitted from the phosphor. The reflective film is formed on one side of the substrate,
The light source device according to claim 4, wherein the phosphor is formed on the reflective film. The light source device according to claim 4, wherein the reflective film transmits the excitation light having an incident angle equal to or less than a predetermined angle. The light source device according to claim 6, wherein the first optical system condenses the excitation light so that an incident angle of the excitation light to the reflection film is equal to or less than the predetermined angle. The light source device according to claim 6, wherein the predetermined angle is 20 degrees. The light source device according to claim 1, further comprising a second optical system that converts the emitted light emitted from the phosphor into parallel light. The light source device according to claim 9, wherein a distance between the second optical system and the phosphor is 1 mm or less. The first wavelength band is a wavelength band including a blue light component, and the second wavelength band is a wavelength band including a red light component and a green light component. Light source device. A laser light source that emits excitation light having a peak wavelength in a first wavelength band including blue light;
Emits emitted light having a peak wavelength in a second wavelength band including green light and red light different from the first wavelength band when irradiated with the excitation light and a substrate rotatable around a rotation axis. And a phosphor having a single light emission characteristic continuously formed on one side of the substrate along the circumferential direction of the substrate, and the excitation light formed on the other side of the substrate. A single fluorescent member having an antireflection film for preventing reflection of
A light source device having a drive shaft connected to the center of the substrate and rotating the fluorescent member so that the irradiation position of the excitation light irradiated on the phosphor moves in the rotation circumferential direction with time And
An image projection unit that modulates light emitted from the light source device unit using three light modulation elements, generates predetermined image light, and projects the generated image light to the outside;
While the driving unit rotates the fluorescent member in a predetermined direction, and the excitation light is irradiated on the fluorescent body over one circumference of the rotational circumferential direction, the fluorescent substance is in the second wavelength band. Emitting the emitted light having a peak wavelength at
The image projection device, wherein the fluorescent member multiplexes and emits a part of the excitation light and the emitted light. The first wavelength band is a wavelength band including a blue light component;
The second wavelength band is a wavelength band including a red light component and a green light component;
The three light modulation elements include a first light modulation element that modulates the light having the blue light component, a second light modulation element that modulates the light having the red light component, and the green light component. The image projection apparatus according to claim 12, comprising: a third light modulation element that modulates light.

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