JP2011186350A - Illuminator and projection type image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact illuminator which performs effective heat radiation and is reduced in power consumption in a projection type display device including a light source using a light emitting element such as a light emitting diode or a semiconductor laser, and to provide the projection type display device. <P>SOLUTION: The illuminator 10 includes: a plurality of light sources; a phosphor layer 211 which is stimulated by one of the light sources and emits light; and a condensing lens which defines an optical path of light emitted from the plurality of light sources and the phosphor layer 211. The phosphor layer 211 is formed on thermally conductive substrate glass 210, and the substrate glass 210 is integrated with a heat sink 240 and fixedly arranged. A blowing fan is disposed near the heat sink 240. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a projection type image display apparatus, and more particularly to a heat dissipation technique of an illumination apparatus provided with a light emitting element as a light source.

  In recent years, with the spread of personal computers, video devices, digital cameras, and the like, there have been many cases of using a projection type image display device (hereinafter also referred to as a projector) as one method for displaying moving images and still images. Yes.

  As a display method of a projector, a method of condensing light output from a light source at a predetermined place and displaying a color image on a screen using a light modulation element such as a DMD (Digital Mirror Device) or a liquid crystal element is generally used. Is.

  In projectors, a high-intensity light source is required to display a high-intensity image on a large screen. Conventionally, high-intensity discharge lamps have been the mainstream as light sources. From the viewpoint of realizing a long life and miniaturization of the light source, there have been proposed examples of using a light emitting element such as a light emitting diode or a semiconductor laser and arranging a plurality of light sources in order to increase luminance (for example, Patent Documents). 1 and 2).

  When using a high-intensity light source, heat dissipation inside the projector is an important issue. Especially in a device that uses a high-intensity discharge lamp, a blower is provided, and the discharge lamp and the blower are integrated into a blower duct. For example, a forced cooling method is used. In this configuration, since the light source and the blower occupy a large space, the power consumption is large and it is difficult to downsize the device. As a measure against this, a method is disclosed in which the light source is a solid light emitting element and the blower is simplified (for example, see Patent Document 3). In this case, a light-emitting diode or a semiconductor laser is used as a light source, and the light source is cooled by blowing air from a fan. In addition, a solid light source that emits blue light is used as a light source, and the red light and the green phosphor layer are irradiated with the blue light as an excitation light source to generate red light and green light.

JP 2003-287802 A JP 2004-341105 A JP 2009-277516 A

  However, the above prior art still has a problem as a heat dissipation structure for a light source using a light emitting element such as a light emitting diode or a semiconductor laser. Even though the light source is shifted from a lamp to a solid light source, a conventional method is used for the heat dissipation structure, and a sufficient effect cannot be exhibited. When using a high-intensity lamp, the lamp is at the highest temperature, so a cooling structure that integrates the lamp and the air blower is effective. However, when using a solid-state light source, the heat-generating part depends on the type of light source. Therefore, in order to effectively dissipate heat from the light emitting unit, it is necessary to cool the most effective part with respect to the temperature rise in the light emitting unit.

  Since the conventional method cools the entire heat generating unit including the light emitting unit and the optical path, it cannot be said that the conventional method effectively corresponds to the heat generation state of each part of the heat generating unit. In particular, a method for cooling a light source has been disclosed, but a cooling method for a phosphor layer that generates a large amount of heat is not disclosed. Therefore, as a heat dissipation measure for the light source unit including the phosphor layer, an efficient heat dissipation method suitable for improving the quality of the device and further miniaturization has been required.

  The present invention solves the above problems, and in a high-brightness projection-type image display device using a light-emitting element, a temperature increase is effectively suppressed, power consumption is low, and a high-brightness and compact lighting device and An object is to realize a projection type image display apparatus.

  In order to solve the above-described problems, an illumination device of the present invention includes a plurality of light sources, a phosphor layer that emits light when excited by any one of the light sources, and an optical path of light emitted from the plurality of light sources and the phosphor layer. An optical means for defining, and forming a phosphor layer on a thermally conductive base material, fixing the base material integrally with the heat dissipation means, and disposing a blower means in the vicinity of the heat dissipation means And

  With such a configuration, in the illumination device that emits light from the light source and the phosphor and illuminates by a predetermined optical path, the phosphor layer formed on the heat conductive substrate is integrated and fixed with the heat radiating means, and the air is blown. By the means, it is possible to cool the heat radiating means from the vicinity. Therefore, the phosphor heat energy generated when the phosphor is excited by the light source can be transferred from the heat conductive base material to the heat radiating means by conduction, and can be air-cooled by the air blowing means in the heat radiating means. When heat is generated, heat can be transferred using conduction and radiation to effectively dissipate heat. Thereby, the most important heat generating part can be radiated and cooled intensively and effectively, the temperature rise of the phosphor layer can be suppressed, and a high quality lighting device can be realized. Further, by increasing the heat dissipation effect, it is possible to reduce the size of the structure related to heat dissipation.

  In the lighting device of the present invention, the heat dissipating means is any one of a heat sink, a heat pipe, and a water-cooled cooling device. With such a configuration, it is possible to configure the heat radiation means using a general-purpose component or a general-purpose device, and a practical and high-quality heat radiation structure can be realized.

  Moreover, the illuminating device of this invention hold | maintains a base material with a heat conductive holding member, and integrates a holding member with a thermal radiation means. With such a configuration, the base material can be fixed integrally with the heat radiating means via the heat conducting member, the base material can be radiated and fixed at the same time, and the design related to heat radiating and fixing the base material Can increase the degree of freedom. Thereby, the holding structure of a base material with a high heat dissipation effect is realizable.

  In the lighting device of the present invention, the holding member includes first and second holding members, and the base material is inserted and held by the first and second holding members, and the first and second holding members are provided. Are pressed against each other by an elastic member, and at least one of the first and second members is integrated with the heat radiating means. With such a configuration, the base material can be held in pressure contact between the two conductive members and integrated with the heat dissipation means, and the thermal conductivity from the base material to the heat dissipation means can be enhanced. Moreover, it can radiate | emit to the thermal radiation means from both surfaces of a base material by heat conduction, and can improve the thermal radiation effect of a base material.

  In the lighting device of the present invention, at least one of the first and second holding members includes a heat dissipation structure. With such a configuration, a heat dissipation function can be imparted to the holding member of the base material, heat can be dissipated together with the heat dissipation means, and the heat dissipation effect can be enhanced.

  In the lighting device of the present invention, the heat dissipation structure is at least one of a heat dissipation fin, a heat sink, and a refrigerant circulation path. With such a configuration, a heat dissipation structure can be configured using general-purpose technology, and a practical and stable quality heat dissipation structure can be realized.

  In the lighting device of the present invention, the first and second holding members are a heat radiating plate and a support fitting, and the support fitting presses and supports the base material on the heat radiating plate via a heat sink. With such a configuration, it is possible to realize a base material holding structure using general-purpose parts and enhance the heat dissipation effect.

  In the lighting device of the present invention, the first and second holding members have an opening in a region facing the phosphor layer formed on the substrate. With such a configuration, the light output from the light source is incident from the opening of the first holding member, the phosphor is excited to emit light, and the output light of the phosphor is emitted from the opening of the second holding member. can do. Accordingly, it is possible to realize a substrate holding structure that enables excitation of the phosphor and a function of heat dissipation.

  In the illumination device of the present invention, the light source is at least one of a laser and an LED, and the phosphor layer uses a laser as an excitation source. With such a structure, a low-power consumption, high-luminance and small-sized lighting device can be realized using a general-purpose light-emitting element and a light-emitting material.

  In the illumination device of the present invention, the light source is a blue laser and a red LED, and the phosphor layer is a phosphor layer that emits green visible light using the blue laser as an excitation source. Illumination of three colors of red, green, and blue can be performed by two types of light sources.

  In the illumination device of the present invention, the light source is a blue laser, and the phosphor layers are phosphor layers that emit green and red visible light using the blue laser as an excitation source. With such a configuration, a lighting device can be configured without using a red LED.

  In the illumination device of the present invention, the light source is a 405 nm laser, and the phosphor layers are phosphor layers that emit blue, green, and red visible light using the near-ultraviolet laser as an excitation source. With such a configuration, a configuration in which direct laser output is not used can be employed.

  According to another aspect of the invention, there is provided a projection display device including at least the illumination device described above, an optical path configuration unit that determines an optical path of light emitted from the illumination device, a light modulation unit disposed on the optical path, and a light modulation unit. Projection means for enlarging and projecting an image modulated by the means. With such a configuration, a low-power consumption, high-brightness, and small-sized projection-type image display device using a light-emitting element and a light-emitting material can be realized.

  According to the present invention, in a projection-type image display device using a light-emitting element, it is possible to effectively dissipate a portion that generates heat at a high temperature, and a small and high-luminance illumination device and projection type that consumes less power. An image display device can be realized.

It is a principal block diagram of the optical apparatus in the projection type image display apparatus of Embodiment 1 of this invention. It is a perspective view which shows the thermal radiation structure of the apparatus. It is a perspective view which shows the thermal radiation structure of the apparatus.

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

(Embodiment 1)
The projection type image display apparatus (hereinafter abbreviated as “this apparatus”) according to Embodiment 1 of the present invention includes an optical apparatus 1, and the optical apparatus 1 has an illumination apparatus 10 and an optical path of light emitted from the illumination apparatus 10. An optical transmission unit 20 as an optical path forming unit to be defined, and a projection lens 26 disposed on the optical path of the optical transmission unit 20 are provided. 26 This apparatus can project a color image on a screen (not shown) through the projection lens 26.

  Hereinafter, the main configuration of the optical device 1 will be described with reference to FIG. FIG. 1 is a main configuration diagram of the optical device 1. As shown in FIG. 1, the optical device 1 includes an illumination device 10, a light transmission unit 20, and a projection lens 26. The illumination device 10 includes two blue lasers 11 and 12, a heat radiating unit 13, and a water-cooled cooling device. 14, a condenser lens 15 and a blower fan 16 are provided. The optical transmission unit 20 includes a rod integrator 21, a relay lens 22, a folding mirror 24, a curved mirror 25, and a DMD (Digital Mirror Device) 23 that is an image display element.

  This apparatus uses a red light emitting diode (LED) or a blue laser (solid light emitting element) as a light source, and uses a phosphor (hereinafter abbreviated as a green phosphor) which is an excitation type light emitting element for green. About 1 to 4 red LEDs are used to ensure the necessary luminance, and the green phosphor is excited using a blue light source (laser). In order to increase the light output of the green phosphor and ensure the green brightness, two blue lasers for excitation are used. The green phosphor formed on the heat conductive substrate held by the heat radiating unit 13 is excited by the blue lasers 11 and 12 to emit green visible light, and passes through the condenser lens 15 from the heat radiating unit 13. Is incident on the rod integrator 21. The detailed configuration of the heat dissipation unit 13 in the illumination device 10 will be described later.

  Note that this apparatus relates to red and blue light emission, and a red light source (LED), a blue light source (laser), and blue lasers 11 and 12 whose optical paths are light sources for exciting the green phosphor shown in FIG. The light source is arranged separately from the light source and is incident on the incident surface 21a of the rod integrator 21 via each optical path, but is not necessary for the description of the present invention. The detailed description and illustration are omitted.

  In the light transmission unit 20, the three colors of red, green, and blue light emitted from the light exit surface 21 b of the rod integrator 21 are emitted from the illumination device 10 via the relay lens 22, the folding mirror 24, and the curved mirror 25. Received and transmitted to DMD 23.

  In the DMD 23, micromirrors are two-dimensionally arranged, and the tilt of each mirror can be changed according to an input signal. The mirror disposed in the pixel displaying white is inclined in a direction in which the incident angle is reduced, and the light incident on the mirror reaches the screen (not shown) via the projection lens 26. On the other hand, the mirror disposed on the pixel for black display of the DMD 23 is inclined in the direction in which the incident angle increases, and the light incident on the mirror is guided to the outside of the projection lens 26 to display black on the screen. At this time, the shape of the exit surface 21b of the rod integrator 21 is transferred onto the DMD 23, and can be condensed efficiently and uniformly. Further, the DMD 23 is driven at a high speed by a drive circuit (not shown) according to, for example, red, green, and blue video signals, and three colors of light are emitted from the light source and the phosphor layer. A color image can be displayed on the screen.

  Next, two configuration examples related to the heat dissipation unit in the illumination device 10 which is a feature of the present apparatus will be described in detail with reference to FIGS. 2 and 3.

  A first configuration example is shown in FIG. FIG. 2 is a perspective view showing the configuration of the heat dissipation unit. 2A and 2B show an overhead perspective view and an elevation perspective view of the heat dissipation unit 100, respectively, and FIG. 2C is a cross-sectional view of the main part showing the internal structure of the heat dissipation unit 13.

  As shown in FIG.2 (c), the thermal radiation unit 100 is the board | substrate glass 110 as a base material which forms a fluorescent substance layer, the pressing block 120 which is a 1st member holding the board | substrate glass 110, and a 2nd member. A heat radiating plate 130, a coil spring 140 as an elastic member, and the like are provided and fixedly disposed (not shown) in the housing of the apparatus.

  In the heat dissipation unit 100, the substrate glass 110 is held by being inserted into a heat dissipation plate 130 having a pressing block 120 and a fin structure 131, and the pressing block 120 and the heat dissipation plate 130 are urged to each other by a coil spring 140. Therefore, the substrate glass 110 is in close contact with the holding block 120 and the heat sink 130 with a predetermined pressure by the coil spring 140. In addition, the holding block 120 includes a heat sink 123 at the back position of the portion in close contact with the substrate glass 110, and also includes a dome-shaped chamber (cooling chamber) 122 that covers the heat sink 123 with the top plate 121. Water is supplied and the water that has cooled the heat sink 123 in the chamber 122 is discharged from the drain 125. The water supply port 124 and the drainage port 125 are connected to a water-cooled water-cooled cooling device 14 (FIG. 1), and a blower fan 16 is disposed in the vicinity of the radiator 14b of the water-cooled cooling device 14. . The water-cooled cooling device 14 includes a circulation pump 14a and a pipe 14c, and can circulate the cooling water in the pipe 14c via the heat radiating unit 13.

  Further, openings 126 and 132 are provided at the center of the top plate 121 and the heat sink 130 of the holding block 120, respectively, and the blue laser L1 is incident from the opening 126 of the holding block 120 and is formed on the substrate glass. By exciting the phosphor layer 111, green visible light L <b> 2 can be emitted and emitted from the opening 132 of the heat sink 130.

  In this configuration example, the substrate glass 110 is integrated with the water cooling type cooling device 14 that is a heat radiating means via a holding block 120 that is a holding member and a heat radiating plate 130, and the phosphor layer formed on the substrate glass 110. It is possible to dissipate heat extremely effectively against the heat generated by 111.

  In contrast to the first configuration example, the second configuration example uses an air-cooling heat dissipation structure.

  FIG. 3 is a perspective view showing the configuration of the heat dissipation unit 200. 3 (a) and 3 (b) show an overhead perspective view and an elevational perspective view of the heat dissipation unit, respectively, and FIG. 2 (c) is a main part sectional view showing the internal structure of the heat dissipation unit. (D) is an A arrow view of Fig.3 (a).

  As shown in FIG. 3C, the heat radiating unit 200 includes a substrate glass 210, a support fitting 220, a heat radiating plate 230, a heat sink 240, a biasing spring 250, and the like. The substrate glass 210 has a phosphor layer 211 on the surface on the side in contact with the heat radiating plate 230 having the fin structure 231, the heat radiating plate 230 is in contact with the surface having the phosphor layer 211, and a support metal fitting on the other surface. The heat sink 240 is in contact via 220, and the heat sink 230 and the heat sink 240 are urged to the substrate glass 210 by the coil spring 250 and are fixed in a sandwich shape. In addition, a cooling fan (not shown) is provided in the vicinity of the heat radiating unit 200, and the heat sink 240 and the heat radiating plate 230 can be air-cooled. Further, openings 241 and 232 are respectively provided in the central portions of the heat sink 240 and the heat sink 230, and the blue laser light L 1 from the light source is incident on the substrate glass 210 from the opening 241, and from the opening 232. The green visible light L2 that emits light when the phosphor layer 211 is excited can be emitted.

  In this configuration example, the substrate glass 210 is integrated with the heat sink 240 and the heat radiating plate 230, which are heat radiating means, via the heat sink 240 and the heat radiating plate 230, so that the phosphor layer 211 formed on the substrate glass 210 generates heat. On the other hand, heat can be radiated extremely effectively. As in the first configuration example, the heat dissipation unit 200 is fixedly disposed in the housing (not shown).

  Next, the detailed configuration of the substrate glass and the reason for disposing the heat dissipation unit will be described.

  In the heat dissipation unit, heat conductive glass (sapphire or the like) is used as the substrate glass, and a phosphor layer is formed on the back surface side of the substrate glass with respect to incident light from the light source. As a method for forming the phosphor layer, coating, screen printing, or the like can be used.

  For example, in FIG. 2, the holding block 120 and the heat dissipation plate 130 are provided with openings 126 and 132, respectively, and the blue laser emits the phosphor layer on the substrate glass from the opening of the heat dissipation unit. The phosphor layer 111 is excited to emit green visible light and can be emitted from the opening. Thereby, green visible light can be emitted from the opening 132 of the heat dissipation plate 130 of the heat dissipation unit. The example shown in FIG. 3 has the same configuration and can exhibit the same effect.

  In addition, in order to minimize the thermal resistance between the substrate glass and the heat dissipation material, it is desirable that improvements such as bonding with a heat conductive adhesive or via a sheet with excellent heat conductivity are performed. Needless to say.

  Moreover, the object of heat dissipation in the heat dissipation unit is a phosphor coated on the surface of the substrate glass. In the substrate glass on which the phosphor layer is formed, thermal energy is generated when the phosphor layer and the glass material absorb excitation light generated from a light source. The phosphor and the glass substrate absorb the excitation light, and the non-radiative energy that does not emit fluorescence in the excitation light and the energy corresponding to the difference between the excitation light and the fluorescence wavelength when the fluorescence is generated are generated as heat, It becomes a factor of the temperature rise of substrate glass. On the other hand, the allowable temperature inside the device is about 60 ° C. However, if the temperature of the substrate glass is partially increased, the temperature range of the phosphor may be exceeded and the wavelength of the phosphor may be exceeded. Since the conversion efficiency is temperature-dependent, when the temperature rises, the amount of light emission decreases, causing the screen to darken.

  The substrate glass provided with the phosphor layer is the first heat generating member in the optical device 1 of the present device, and is most effective in suppressing the temperature increase of the optical device 1 by concentrating and radiating the substrate glass. It can be demonstrated.

  As described above, according to the present apparatus, for the three colors of red, blue, and green, heat is emitted mainly from the green phosphor that generates the greatest heat and the substrate glass that holds the phosphor. It is possible to effectively prevent the projection display screen from becoming dark by suppressing a decrease in luminous efficiency due to the rise.

  This device uses light emitting diodes for red and lasers for blue, and green phosphors that emit light when excited by blue lasers. However, light emitting diodes, organic EL, semiconductor lasers, etc. Needless to say, it is possible to configure light sources of three colors by using various combinations.

  By the way, in the above embodiment, the light source is a blue laser and the phosphor layer emits green light, but the red color phosphor layer is arranged on another optical path and synthesized to obtain a white color. The cooling structure of the present invention can also be applied here.

  On the other hand, in the above-described configuration including the embodiment, the blue and blue laser light is used. However, there is a concern that the laser light may cause speckles or have safety standards.

  As an improvement measure against these, the light source is a 405 nm laser, and the phosphor layer is configured as a phosphor layer that emits visible light of blue, green, and red using the near ultraviolet laser as an excitation source. I can take it. Since all the light at this time is obtained by a phosphor, the influence of speckle can be eliminated. In this case, it is apparent that the present invention is effective from the necessity of cooling the phosphor layers of three colors.

  In this apparatus, DMD is used as an image display element, but a liquid crystal display element or the like can be used instead of DMD.

  Moreover, although the example which used the water cooling type cooling device and the heat sink as a thermal radiation means was shown in this apparatus, it can replace with this and can use a heat pipe.

  Further, in this apparatus, in the heat dissipation unit, one of the two substrate glass holding members and the cooling device as the heat dissipation means are integrated, but a method of integrating both of the two holding members with the cooling device However, it goes without saying that the same effect is exhibited.

  INDUSTRIAL APPLICABILITY The illumination device and the projection-type image display device according to the present invention can effectively dissipate a portion that generates heat at a high temperature in a projector using a light emitting element, and realize a small projector with low power consumption. Can do. Therefore, the present invention can be applied as an illumination device and a projection image display device that require low power consumption and small size and light weight.

1 Optical device 10 Illumination device 11, 12 Light source (blue laser)
13, 100, 200 Radiation unit 14 Cooling device 14a Circulation pump 14b Radiator 14c Piping 15 Condensing lens 16 Blower fan 20 Light transmission part 21a Incident surface 21b Emission surface 21 Rod integrator 22 Relay lens 23 DMD
24 Folding mirror 25 Curved mirror 26 Projection lens 110, 210 Substrate glass 120 Holding block 121 Top plate 122 Chamber 123, 240 Heat sink 124 Water supply port 125 Drain port 126, 132, 232, 241 Opening portion 130, 230 Heat radiation plate 131 Fin structure 140 , 250 Coil spring 220 Support bracket

Claims (13)

A plurality of light sources; a phosphor layer that emits light when excited by any one of the light sources; and an optical unit that determines an optical path of light emitted from the plurality of light sources and the phosphor layer, and the phosphor layer is heated. An illuminating device, wherein the lighting device is formed on a conductive base material, the base material is integrally fixed with a heat dissipating means, and a blower means is disposed in the vicinity of the heat dissipating means. The lighting device according to claim 1, wherein the heat radiating means is any one of a heat sink, a heat pipe, and a water-cooled cooling device. The lighting device according to claim 1, wherein the base material is held by a heat conductive holding member, and the holding member is integrated with the heat dissipation unit. The holding member includes a first holding member and a second holding member, and the base member is inserted and held by the first holding member and the second holding member, and the first holding member and the second holding member are mutually held by an elastic member. The lighting device according to claim 3, wherein at least one of the first and second members is integrated with the heat dissipating means. The lighting device according to claim 4, wherein at least one of the first and second holding members includes a heat dissipation structure. The lighting device according to claim 5, wherein the heat dissipation structure is at least one of a heat dissipation fin, a heat sink, and a refrigerant circulation path. The lighting device according to claim 5, wherein the first and second holding members are a heat sink and a support metal, and the support metal presses and supports the base material against the heat sink via a heat sink. . The said 1st and 2nd holding member has an opening part in the area | region facing the fluorescent substance layer formed on the said base material, The any one of Claim 4 to 7 characterized by the above-mentioned. The lighting device described. The illumination device according to any one of claims 1 to 8, wherein the light source is at least one of a laser and an LED, and the phosphor layer uses a laser as an excitation source. The lighting device according to claim 9, wherein the light source is a blue laser and a red LED, and the phosphor layer is a phosphor layer that emits green visible light using the blue laser as an excitation source. The illumination device according to claim 9, wherein the light source is a blue laser, and the phosphor layer is each phosphor layer that emits green and red visible light using the blue laser as an excitation source. The illumination according to claim 9, wherein the light source is a 405 nm laser, and the phosphor layer is a phosphor layer that emits blue, green, and red visible light using the near-ultraviolet laser as an excitation source. apparatus. At least the illumination device according to any one of claims 1 to 12, an optical path forming unit that defines an optical path of light emitted from the illumination device, and a light modulation unit disposed on the optical path, A projection type image display apparatus comprising: projection means for enlarging and projecting the image modulated by the light modulation means.

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