JP5605047B2 - Light source device and projection display device using the same - Google Patents

Description

  The present invention relates to a projection display apparatus that irradiates an image formed on a small light valve with illumination light and enlarges and projects it onto a screen by a projection lens.

  A discharge lamp is widely used as a light source of a projection display device using a light valve of a liquid crystal or a mirror deflection type digital micromirror device (DMD). Discharge lamps have the problem of short life and low reliability. In order to solve this problem, in recent years, a projection display apparatus using a solid-state light source such as a semiconductor laser or a light emitting diode as a light source has been disclosed. FIG. 9 shows a projection display apparatus using a conventional solid light source and DMD.

  Ultraviolet light from the light emitting diode 1 is incident on the color wheel 2. The color wheel 2 is formed with a reflective film that transmits ultraviolet light and reflects visible light, and a red, green, and blue phosphor layer is formed on each of the areas where the disk is divided into three areas on the exit side of the reflective film. doing. Red, green, and blue color lights are emitted by the ultraviolet rays incident on the color wheel 2. The emitted light is transmitted and reflected through the relay lens 3, the reflection mirror 4, and the prism 5 and enters the DMD 6. In accordance with the video signal, the light modulated by the DMD 6 is enlarged and projected by the projection lens 7 (see Patent Document 1).

JP 2004-341105 A

  In general, as a method for increasing the light use efficiency of a projection display device, there is a method of reducing the Etendue, which is the product of the light emitting area of a light source and the solid angle of a light beam emitted from the light source. In FIG. 9, the laser light that is a solid light source is condensed, and the phosphor screen is irradiated with the Gaussian spot light to cause excitation light emission. Therefore, the area of the spot light becomes the light emission area of the light source. The light distribution characteristic of the light emitted from the fluorescent screen is a Lambertian distribution with uniform directivity. In order to reduce the etendue, the spot light may be reduced, or the directivity of the light distribution characteristic may be increased to reduce the solid angle of the emitted light flux. Although it is possible to reduce the spot light to be irradiated by increasing the power of the condenser lens, the fluorescence conversion efficiency, which is the energy ratio of the fluorescent light to the energy of the excitation light, is the light energy per unit area. As the light density increases, it decreases due to absorption saturation of the phosphor. For this reason, even if the area of the spot light is reduced beyond a certain light density that causes absorption saturation of the phosphor, the light utilization efficiency is not improved. Therefore, in order to increase the luminance and efficiency of the light source, it has been a problem to reduce the solid angle of the fluorescence emission of the light source, that is, to increase the directivity of the light distribution characteristics of the light source. As a light valve, a projection display device using a liquid crystal or a mirror deflection type DMD has been widely put into practical use. For this reason, in particular, it has been a problem to construct a light source device that can reduce the solid angle of the emitted light beam and a projection display device using the light source device, which is suitable for the optical system of each light valve.

A light source device according to the present disclosure is a light source used in a projection display device, and transmits light from a laser , an annular fluorescent region having a phosphor layer that emits fluorescence upon receiving light from the laser, and light from the laser. Provided in the fluorescent substrate in which the annular transmission regions are alternately formed in the radial direction, and on the side where the fluorescence is emitted from the fluorescent substrate , corresponding to the fluorescence region and not corresponding to the transmission region, the incident angle of the incident light And a prism array having a prism surface that separates into refracted light and reflected light. The gist of this prism array is to enhance fluorescence directivity by multiple reflection between the prism surface and the fluorescent substrate. In the light source device having the above configuration, since the light emitted by the solid light source has high directivity, the solid angle of the emitted light beam can be reduced, and a highly efficient light source can be configured.

In the above light source device, the prism array includes a plurality of quadrangular pyramid prisms, and the plurality of quadrangular pyramid prisms may be arranged so that the incident surface side facing the fluorescent substrate is a bottom surface of the quadrangular pyramid. That is, in the prism array, the plane side is the entrance surface and the prism surface side is the exit surface.

A projection display device of the present disclosure includes a light source unit, an image forming unit that forms an image according to a video signal, an illumination unit that collects light from the light source device and illuminates the image forming unit, and an image forming unit And a projection unit for enlarging and projecting the image formed in (1) above, and using the above light source device for the light source unit. Since the light source device described above is used, a bright projection display device having a long life, high light use efficiency, and high brightness can be configured.

  If the intensity of the laser beam is high, the light source device need not include a plurality of lasers, and the light condensing means can be omitted.

  According to the present invention, a projection display device having a long life and high light use efficiency can be configured by a solid-state light source and a light source device including a prism array element in the vicinity of a phosphor screen.

1 is a configuration diagram of a light source device according to Embodiment 1 of the present invention. Perspective view of prism array Schematic diagram showing the light beam appearance of the fluorescent substrate and prism array Configuration diagram of fluorescent substrate and prism array Graph showing the spectral characteristics of the light emitted from the light source device Configuration diagram of a projection display apparatus according to Embodiment 2 of the present invention Configuration diagram of a projection display apparatus according to Embodiment 3 of the present invention Configuration diagram of fluorescent substrate and prism array Configuration of a conventional projection display device

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a configuration diagram of a light source device showing an embodiment of the present invention.

  11 is a blue semiconductor laser, 12 is a lens array, 13 is a condensing lens as a condensing means, 14 is a fluorescent substrate in which a reflective film surface 15 and a fluorescent surface 17 are formed on a transparent substrate 16, 18 is a motor, 19 Is a reflective polarizing element. In the figure, the polarization directions of the laser light and the light emitted from the light source device and the light distribution aspect of the light emitted from the light source device are shown.

  The blue semiconductor laser 11 is a laser that emits light having a wavelength of 440 nm to 455 nm. Light emitted from the plurality of semiconductor lasers 11 is collected by each lens of the lens array 12 and converted into substantially parallel light. The collimated light from the lens array 12 is superimposed by the condenser lens 13 on the spot light having a diameter of 1 to 3 mm where the light intensity is 13.5% of the peak intensity, and is incident on the fluorescent substrate 14. The fluorescent substrate 14 is a circular substrate having a motor 18 at the center and capable of rotation control. The reflective film surface 15 of the fluorescent substrate 14 is a dielectric thin film that transmits blue component light of 440 nm to 455 nm and reflects green and red color lights. The fluorescent screen 17 has a fluorescent region and a transmissive region in which a phosphor layer is formed. Light incident on the fluorescent region emits green and red component color lights and emits from the fluorescent substrate 14. Further, the green and red component color lights emitted by fluorescence and emitted toward the condenser lens 13 are reflected by the reflecting film surface 15 and emitted from the fluorescent substrate 14. The light incident on the transmission region is diffused and transmitted as blue light, and is emitted from the fluorescent substrate 14. The light emitted from the fluorescent substrate 14 enters a circular prism array 19 arranged in the vicinity of the fluorescent substrate 14. The prism array 19 is a prism array in which minute prisms are arranged on a plane, and the plane side is arranged on the incident surface and the prism surface side is arranged on the emission surface through a minute air layer with respect to the fluorescent substrate 14. The light incident on the prism array 19 is separated into refracted light and reflected light corresponding to the angle of incidence on the prism surface, and the reflected light is diffusely reflected by the fluorescent substrate 14 and incident on the prism array 19 again. Due to this multiple reflection, the light distribution of the light emitted from the prism array 19 has high directivity.

  FIG. 2 is a perspective view of the prism array. Each prism 20 is a quadrangular pyramid prism, and the angle of the opposing prism slope is 90 degrees. The pitch of the prism array 19 is set to 20 to 50 μm in order to reduce the spread of the reflected light to the fluorescent substrate 14. The prism array 19 is formed by molding glass or resin.

  FIG. 3 is a schematic diagram showing the appearance of light rays on the fluorescent substrate and the prism array. In the figure, a light distribution 21 of fluorescence emission light and a light distribution 22 of diffuse reflection by light reflected by the prism surface are shown. The Lambertian distribution light distribution 21 that emits fluorescence is separated into refracted light and reflected light including total reflection on the prism surface, and the reflected light is further reflected on the adjacent prism surface and enters the fluorescent substrate 14. The light incident on the fluorescent region of the fluorescent substrate 14 becomes the light distribution 22 having a Lambertian distribution again by the diffuse reflection on the phosphor layer and the reflection on the reflection film surface 15, and then enters the prism array 19 again. Due to such multiple reflection between the fluorescent substrate 14 and the prism array 19, the directivity of the light emitted from the prism array 19 is increased, and the light is converted into a light beam having a small solid angle. The emitted light flux is improved by about 1.4 times in a range of ± 45 degrees, with the optical axis in the light traveling direction being 0 degrees as compared with the case of the completely diffuse light distribution.

  FIG. 4 shows the configuration of the fluorescent substrate and the prism array. 2A is a front view of the fluorescent substrate 14 and the prism array 19, FIG. 2B is a plan view of the prism array 19, and FIG. 2C is a plan view of the fluorescent screen 17. FIG. The prism array 19 and the phosphor screen 17 are observed from the outgoing light side. Reference numeral 25 denotes spot light of the irradiated laser beam. The fluorescent screen 17 is formed by alternately forming an annular fluorescent region (shaded portion) 24 and an annular transmission region 23 in the radial direction. The transmissive region 23 has a transparent substrate as a diffusing surface, and an annular width thereof is approximately ½ of an annular width of the fluorescent region 24. The spot light 25 incident on the fluorescent screen 17 is arranged to irradiate the fluorescent region 24 and the transmissive region 23. In FIG. 4, the number of the circular regions of the fluorescent region 24 and the transmissive region 23 is one for the incident region of the spot light 25. By forming an annular width of the fluorescent region 24 and the transmissive region 23 to be narrower and more than two each, the intensity change of the fluorescent color light and the transmitted blue light due to the positional deviation of the spot light 25 and the fluorescence and transmissive region can be changed. It can also be made smaller. The prism array 19 forms a prism array portion (horizontal line portion) corresponding to the annular fluorescent region of the fluorescent screen 17. A prism array is not formed in the transmission region. The transmission region 23 is a diffusion surface whose surface has a fine uneven shape, and is a diffusion surface whose diffusion angle, which is an angle that is ½ of the peak intensity, is approximately 5 degrees. For this reason, the light distribution of the light diffused and transmitted through the transmission region has high directivity, and the solid angle of the light is small. The reason why the diffusion surface is used is that the speckle of the irradiated laser light is relaxed and the intensity distribution of the spot light is made uniform. The prism array 19 is arranged on the phosphor screen via a minute air layer using a spacer, but may be bonded to the phosphor screen or the prism array with an adhesive having a certain refractive index difference. By bonding, the distance between the fluorescent screen and the prism surface is reduced, and the spot light can be reduced.

In the phosphor layer of the phosphor region 24, a Ce-activated YAG yellow phosphor that is excited by blue component light and emits yellow light containing green and red components is formed. A typical chemical structure of the crystal matrix of this phosphor is Y ₃ Al ₅ O ₁₂ . The fluorescent region 24 excited by the spot light emits green and red component light, and the transmissive region 23 emits blue light. By rotating the fluorescent substrate 17, the temperature rise of the phosphor due to the excitation light can be suppressed, and the fluorescence conversion efficiency can be stably maintained. Also, the temperature rise of the prism array can be suppressed. As the phosphor, an orthosilicate phosphor which is an oxide phosphor having the same emission characteristics as the YAG yellow phosphor may be used.

  FIG. 5 shows the spectral characteristics of the light emitted from the light source device. The blue component is the laser emission, and the green and red components are the fluorescence emission spectral characteristics. The ratio of the blue component to the green and red components can be controlled by the ratio of the width of the fluorescent region to the transmissive region of the annular phosphor screen and the transmittance of those surfaces, and the desired white chromaticity can be obtained. it can. By providing the prism array, the luminous flux emitted from the light source device can be improved by about 1.4 times in the range of ± 45 degrees from the light distribution on the complete diffusion surface.

  As described above, a long-life, low-eternity light is achieved by a plurality of lasers, a fluorescent substrate having a fluorescent surface and a reflective film surface on which a fluorescent region and a transmissive region are formed, and a prism array disposed in the vicinity of the fluorescent substrate. Thus, a light source device with high light utilization efficiency can be configured. By constructing a projection display device using this light source device and a light valve, it is possible to construct a projection display device having a long life and high efficiency.

(Embodiment 2)
FIG. 6 is a configuration diagram of a projection display apparatus according to the embodiment of the present invention.

  As the liquid crystal light valve, a TN mode or VA mode transmissive liquid crystal panel of an active matrix type in which a thin film transistor is formed in a pixel region is used.

  The light source device 28 includes a blue semiconductor laser 11, a lens array 12, a condenser lens 13, a fluorescent substrate 14 in which a reflective film surface 15 and a fluorescent surface 17 are formed on a transparent substrate 16, a motor 18, and a prism array 19. The above is the light source device of the present invention. 29 is a condensing lens, 30 and 31 are first and second lens array plates, 32 is a polarization converting optical element, 33 is a superimposing lens, 34 is a blue reflecting dichroic mirror, and 35 is a green reflecting dichroic mirror, 36, 37, and 38 are reflection mirrors, 39 and 40 are relay lenses, 41, 42, and 43 are field lenses, 44, 45, and 46 are incident-side polarizing plates, 47, 48, and 49 are liquid crystal panels, and 50, 51, and 52 are liquid crystal panels. Is an output side polarizing plate, 53 is a color combining prism composed of a red reflecting dichroic mirror and a blue reflecting dichroic mirror, and 54 is a projection lens.

  As the fluorescent substrate 14 and the prism array 19 of the light source device 28, the fluorescent substrate and the prism array shown in FIG. 4 are used. White light emitted from the light source device 28 is condensed by the condenser lens 29 and converted into substantially parallel light. The light converted into substantially parallel light is incident on the first lens array plate 30 composed of a plurality of lens elements. The light beam incident on the first lens array plate 30 is divided into a number of light beams. A large number of the divided light beams converge on the second lens array plate 31 composed of a plurality of lenses. The lens elements of the first lens array plate 30 have an opening shape similar to the liquid crystal panel. The focal lengths of the lens elements of the second lens array plate 31 are determined so that the first lens array plate 30 and the liquid crystal panels 47, 48, and 49 have a substantially conjugate relationship. The light emitted from the second lens array plate 31 enters the polarization conversion optical element 32. The polarization conversion optical element 32 includes a polarization separation prism and a half-wave plate, and converts natural light from the light source into light of one polarization direction. Light from the polarization conversion optical element 32 enters the superimposing lens 33. The superimposing lens 33 is a lens for superimposing and illuminating the light emitted from the lens elements of the second lens array plate 31 on the liquid crystal panels 47, 48, and 49. The condensing lens 29, the first and second lens array plates 30, 31, the polarization conversion optical element 32, and the superimposing lens 33 serve as illumination means. The light from the superimposing lens 33 is separated into blue, green and red color light by a blue reflecting dichroic mirror 34 and a green reflecting dichroic mirror 35 which are color separation means. The green color light passes through the field lens 41 and the incident side polarizing plate 44 and enters the liquid crystal panel 47. After the blue color light is reflected by the reflection mirror 36, it passes through the field lens 42 and the incident side polarizing plate 45 and enters the liquid crystal panel 48. The red color light is transmitted and refracted and reflected by the relay lenses 39 and 40 and the reflection mirrors 37 and 38, passes through the field lens 43 and the incident side polarizing plate 46, and enters the liquid crystal panel 49.

  The three liquid crystal panels 47, 48, and 49 change the polarization state of incident light by controlling the voltage applied to the pixels according to the video signal, and the transmission axes are orthogonal to both sides of the respective liquid crystal panels 47, 48, and 49. The incident-side polarizing plates 44, 45, and 46 and the outgoing-side polarizing plates 50, 51, and 52 arranged in such a manner are combined to modulate light to form green, blue, and red images. Each color light transmitted through the exit side polarizing plates 50, 51 and 52 is reflected by the color combining prism 53, and each red and blue color light is reflected by the red reflecting dichroic mirror and the blue reflecting dichroic mirror to be combined with the green color light. Then, the light enters the projection lens 54. The light incident on the projection lens 54 is enlarged and projected on a screen (not shown). Since the directivity of the light emitted from the light source device 28 is high and the ethane is small, the light use efficiency of the projection display device is increased. In addition, since the light valve uses three liquid crystal panels that use polarized light instead of the time-division method, there is no color breaking, color reproduction is good, and a bright and high-definition projected image can be obtained.

  A transmissive liquid crystal panel is used as the liquid crystal light valve, but a reflective liquid crystal panel may be used. By using a reflective liquid crystal panel, a compact and high-definition projection display device can be configured.

  As described above, a light source device composed of a solid-state light source, a fluorescent substrate having a fluorescent surface and a reflective film surface in which a fluorescent region and a transmission region are formed in an annular shape, and a prism array disposed in the vicinity of the fluorescent substrate is used. By configuring the projection display device in this manner, a light source device with a small etendue can be configured, and a long-life and high-efficiency projection display device can be configured.

(Embodiment 3)
FIG. 7 is a configuration diagram of a projection display apparatus showing an embodiment of the present invention.

  As the light valve, one time-division DMD is used. The light source device 78 includes a blue semiconductor laser 61, a lens array 62, a condenser lens 63, a fluorescent substrate 64 having a reflective film surface 65 and a fluorescent surface 67 formed on a transparent substrate 66, and a motor 68. The configuration is the same as that of the light source device shown in Embodiments 1 and 2. Different fluorescent substrates 64 and prism arrays 69 are used. 80 is a condensing lens, 81 is a rod, 82 is a relay lens, 83 is a reflecting mirror, 84 is a field lens, 85 is a total reflection prism, 86 is a DMD, and 87 is a projection lens. On the fluorescent screen 67 of the fluorescent substrate 64 of the light source device 78, a fluorescent region and a transmission region are formed in which a fluorescent material layer that fluoresces green and red components is formed in a region divided into three in the rotation direction. Light emitted from the light source device 78 emits green, red, and blue color lights in time series by the rotation of the fluorescent substrate 64. The light from the light source device 78 is condensed on the incident surface of the rod 81 by the condenser lens 80. The rod 81 is columnar glass having a rectangular entrance surface and exit surface. The light incident on the rod 81 propagates to the exit surface of the rod 81 by multiple reflection including total reflection. A non-uniform light flux on the entrance surface becomes a uniform light flux on the exit surface. Light emitted from the rod 81 is refracted and reflected by the relay lens 82, the reflection mirror 83, the field lens 84, and the total reflection prism 85, respectively, and then enters the DMD 86. The distance between the surfaces of the relay lens 82 and the field lens 84 and the focal length are determined so that the exit surface of the rod 81 and the DMD 86 surface have a conjugate relationship. The field lens 84 condenses the illumination light on the projection lens 87 efficiently. The total reflection prism 85 is a prism that totally reflects illumination light and transmits projection light from the DMD 86. The light emitted from the rod 81 becomes rectangular illumination similar to the display area on the DMD 86, and illuminates the surface of the DMD 86 with high efficiency and uniformity. The condenser lens 80, the rod 81, the relay lens 82, the reflection mirror 83, the field lens 84, and the total reflection prism 85 are used as illumination means. The light incident on the DMD 86 deflects only the light beam necessary for image formation according to the video signal, passes through the total reflection prism 85, and then enters the projection lens 87. The projection lens 87 enlarges and projects the image light modulated and formed by the DMD 86. Since one DMD is used for the light valve, a small and light projection display device can be configured.

FIG. 8 shows a configuration diagram of the fluorescent substrate and the prism array. 2A is a front view of the fluorescent substrate 64 and the prism array 69, FIG. 2B is a plan view of the prism array 69, and FIG. 2C is a plan view of the fluorescent screen 67. FIG. The fluorescent substrate 64 is a circular substrate that can be rotationally controlled. The prism array 69 and the fluorescent screen 67 are observed from the outgoing light side. Reference numeral 73 denotes spot light of the irradiated laser beam. The fluorescent screen 67 is formed by dividing a green component fluorescent region (shaded portion) 70, a red component fluorescent region (vertical line portion) 71, and a transmission region 72 in the rotation direction. The transmissive region 72 is a transparent substrate made of a diffusion surface. Due to the rotation of the fluorescent substrate, the spot light 73 incident on the fluorescent screen 67 irradiates the fluorescent regions 70 and 71 and the transmission region 72 in time series, and diffuses and transmits green and red color light respectively as fluorescence emission or blue color light. To do. By changing the division angle of the fluorescent regions 70 and 71 and the transmissive region 72, the ratio of the color light emitted in time series can be changed, and light with a desired white balance can be obtained. The prism array 69 forms a prism array region (horizontal line portion) corresponding to the fluorescent region of the fluorescent screen 67. A prism array is not formed in the transmission region 72. The transmissive region 72 is a diffusing surface whose surface has fine irregularities, and is a diffusing surface having a diffusing angle that is an angle that is ½ of the peak intensity. For this reason, the light distribution of the light diffused and transmitted through the transmission region has high directivity, and it is not necessary to form a prism array. The reason why the diffusion surface is used is that the speckle of the irradiated laser light is relaxed and the intensity distribution of the spot light is made uniform. The prism array 69 is arranged using a spacer and a fluorescent surface 67 and a minute air layer, but may be bonded to the fluorescent surface 67 and the prism array 69 with an adhesive having a certain refractive index difference. . By adhering and bonding, the distance between the fluorescent screen 67 and the prism array 69 is reduced, and the spot light can be reduced. The phosphor layer in the phosphor region 70 is a Ce-activated YAG yellow phosphor that is excited by blue component light and contains a green component, and the phosphor has a relatively small red component at an emission peak of around 540 nm. A phosphor is selected and used. In the phosphor layer of the fluorescent region 71, a nitride phosphor that is excited by blue component light and fluoresces a component including a red component is formed. An example of the nitride phosphor is Ca ₂ Si ₅ N ₈ : Eu. This phosphor has an emission peak in the vicinity of a wavelength of 610 nm, and emits light in a wide band with a half-value width of about 100 nm. Moreover, the conversion efficiency fall by temperature rise is also smaller than a YAG type yellow fluorescent substance. The excited fluorescent regions 70 and 71 fluoresce green and red light components, and the transmissive region 72 emits blue light. By rotating the fluorescent substrate 64, it is possible to suppress the temperature rise of the phosphor due to the excitation light and to stably maintain the fluorescence conversion efficiency.

The green phosphor may be an orthosilicate phosphor that is an oxide phosphor having the same emission characteristics as the YAG yellow phosphor. An oxynitride phosphor may be used as the red phosphor. As the oxynitride phosphor, there is a CaAlSiN ₃ : Eu phosphor. This phosphor has an emission peak in the vicinity of 650 nm, and emits light in a wide band with a half-value width of about 100 nm.

  As described above, a solid-state light source, a fluorescent substrate including a fluorescent region that fluoresces green and red components in a region divided in the rotation direction, a fluorescent surface that forms a transmission region, and a reflective film surface, and the vicinity of the fluorescent substrate By constructing a projection display device using a light source device composed of a prism array arranged in a light source, a light source with a small etendue can be constructed, and a long-life and high-efficiency projection display device can be constructed. it can.

  In any of the above embodiments, a plurality of lasers of the light source device are provided. However, if the intensity of the laser beam is high, it is not necessary to provide a plurality of lasers, and the light condensing means can be omitted.

  The present invention relates to a projection display device using a light valve.

DESCRIPTION OF SYMBOLS 11, 61 Semiconductor laser 12, 62 Lens array 13, 63 Condenser lens 14, 64 Fluorescent substrate 15, 65 Reflective film surface 16, 66 Transparent substrate 17, 67 Fluorescent surface 18, 68 Motor 19, 69 Prism array 20 Prism 21, 22 Light distribution 23, 72 Transmission region 24 Fluorescence region 25, 73 Spot light 28, 78 Light source device 29, 80 Condensing lens 30 First lens array plate 31 Second lens array plate 32 Polarization conversion optical element 33 Superposition lens 34 Blue reflective dichroic mirror 35 Green reflective dichroic mirror 36, 37, 38, 83 Reflective mirror 39, 40, 82 Relay lens 41, 42, 43, 84 Field lens 44, 45, 46 Incident side polarizing plate 47, 48, 49 Liquid crystal panel 50, 51, 52 Output side polarizing plate 53 Color Prisms 54,87 fluorescent region 81 rod 85 of the fluorescent region 71 the red component of the projection lens 70 green component total reflection prism 86 DMD

Claims (3)

With laser,
A fluorescent substrate in which an annular fluorescent region having a phosphor layer that emits fluorescence upon receiving light from the laser and an annular transmission region that transmits light from the laser are alternately formed in the radial direction ;
A prism surface is provided on the side where the fluorescent light exits from the fluorescent substrate , corresponding to the fluorescent region and not corresponding to the transmissive region, and is separated into refracted light and reflected light according to an incident angle of incident light. A prism array, and a light source device comprising:
The light source device characterized in that the prism array enhances the directivity of the fluorescence by multiple reflection between the prism surface and the fluorescent substrate. The light source device according to claim 1,
The prism array is
Having a plurality of square pyramid prisms,
The light source device, wherein the plurality of quadrangular pyramid prisms are arranged such that an incident surface side facing the fluorescent substrate is a bottom surface of the quadrangular pyramid. A light source unit, an image forming unit that forms an image in response to a video signal, an illumination unit that collects light from the light source device to illuminate the image forming unit, and an image formed by the image forming unit. A projection display device comprising: a projection unit that performs enlargement projection;
3. A projection display device using the light source device according to claim 1 or 2 for the light source unit.

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