JP4206867B2 - Light source device, projection display device - Google Patents

Description

  The present invention relates to a light source device and a projection display device, and more particularly to a light source device having a configuration suitable for cooling a light source.

Projection-type display such as a projector that displays light by making light emitted from the light source device incident on light modulation means such as a liquid crystal light valve, and projecting the image light modulated by the light modulation means on a screen by a projection lens or the like. The device is widely known. A solid light source such as an LED light source is employed as a light source used in the light source device of the projection display device. Since such a solid light source generates heat with light emission, cooling is required to improve the light emission efficiency. As a method of cooling such a solid light source, for example, there is one disclosed in Patent Document 1.
JP 7-68840 A

  In the said patent document 1, it comprised from the LED support bar which mounted LED, and the heat conductor which is arrange | positioned and contacted with this LED support bar thermally, and comprised the U-shaped duct inside. A cooling system is disclosed. In this case, since the duct is only U-shaped, heat exchange is possible only in the portion of the U-shaped duct close to the mounted LED, and the contact area with the portion to be cooled is small and high cooling efficiency is achieved. It was not obtained.

  The present invention has been made in view of the above problems, and provides a light source device capable of cooling a solid light source with high efficiency even when a large amount of heat is generated from the solid light source including a minute heat generation region. It is aimed. In addition, the present invention provides a light source device that has a simple structure for cooling the solid-state light source and can contribute to reduction in manufacturing cost. Furthermore, an object of the present invention is to provide a highly reliable projection type display device including such a light source device.

  In order to solve the above problems, a light source device of the present invention includes a solid light source and a pedestal on which the solid light source is placed, and the pedestal has a side opposite to the placement surface of the solid light source. A predetermined digging portion is formed on the surface, and a cooling pipe in which a cooling fluid for cooling the solid-state light source flows is disposed in the digging portion.

  According to such a light source device, the cooling pipe is disposed in the digging portion of the pedestal on which the solid light source is placed, and the cooling fluid is circulated therein to cool the pedestal and indirectly cool the solid light source. It becomes possible to do. And in this invention, since it is the structure which forms a dug part in a base and arrange | positions a cooling pipe in it, it can become a simple method. In addition, since the cooling fluid is circulated on the surface opposite to the mounting surface of the solid light source, that is, on the side opposite to the light emitting surface, liquid is used as the cooling fluid, and bubbles or the like are contained in the cooling fluid. In the case of the occurrence of the problem, it is not optically affected by the bubbles. Furthermore, for example, as compared with a configuration in which the solid light source is immersed in the cooling fluid, the optimum type and flow rate of the cooling fluid can be selected relatively freely. As the cooling fluid in the present invention, a gas such as air can be used in addition to a liquid such as water.

  In particular, when the cooling pipe is arranged along the digging shape of the digging portion, the contact area between the digging portion and the cooling pipe increases, and the cooling efficiency becomes extremely high. That is, by arranging the cooling pipe along the digging shape, the digging surface of the pedestal is efficiently cooled, and the solid light source formed on the surface side of the digging portion is also cooled with high efficiency. Become.

  In addition, the said dug part shall be formed in the light emission back side of the said solid light source, and shall be provided with the island-like part or columnar part which protruded on the opposite side to the light emission side of this solid light source. And the said cooling pipe shall be formed in a spiral form in the form surrounding the dug part provided with shapes, such as such an island-like part or a columnar part. By disposing the spiral cooling pipe so as to surround the digging portion, it becomes possible to cool the pedestal with higher efficiency, and as a result, formed on the surface side of the digging portion. It is also possible to cool the solid light source more efficiently. In addition, as a more specific configuration of the dug portion, an island shape having an inverted cone shape, an inverted frustoconical shape, or a column shape is used, and the island shape portion is preferably cooled by a helical cooling pipe. Is possible.

  A gap between the dug portions where the cooling pipes are disposed may be filled with a heat conductive material. In other words, for example, when a helical cooling pipe is arranged in the digging portion, several gaps are formed in the digging portion, and this gap is filled with a heat conductive material such as silver. By doing so, the air layer is eliminated, heat conduction is performed well in the gap, that is, the cold heat from the cooling pipe is surely transmitted to the pedestal, and the cooling pipe is firmly inside the digging portion. And can be fixed. By using a silver paste, molten metal or the like as such a heat conductive material, it is possible to suitably fill the gap and fix it after curing.

  In the cooling pipe, the flow path of the cooling fluid may be covered with a heat insulating material. In this case, it is possible to avoid problems such as the cooling fluid being heated before reaching the vicinity of the position where the solid light source as the cooling target portion is disposed, and cooling the cooling target portion (solid light source) more reliably. Can be performed. Furthermore, a heat insulating material may be provided between the circulation path and the circulation return path of the cooling fluid. In this case, the cooling fluid after the heat exchange (cooling fluid flowing in the return path) This makes it possible to avoid problems such as warming of the cooling fluid before heat exchange (cooling fluid flowing in the forward path). As the heat insulating material, it is possible to provide a foamed polypropylene tube, glass wool or the like by pasting.

  Next, a projection type display device of the present invention is characterized by comprising the above-described light source device. Specifically, the light source device includes a light modulation device that modulates light emitted from the light source device, and a projection device that projects light modulated by the light modulation device. Can do. Since such a projection type display device includes a light source device with excellent cooling efficiency, it is difficult to cause wear of the light source device due to heat generation or decrease in light emission efficiency of the light source device, and is extremely reliable. It becomes.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, in each figure, in order to make each layer and each member the size which can be recognized on drawing, the scale is varied for every layer and each member.

(Light source device)
FIG. 4 is a schematic cross-sectional view showing a schematic configuration of a light source device as an embodiment of the present invention, and FIGS. 1 to 3 are schematic diagrams for explaining a manufacturing process of the light source device of FIG. First, the light source device 100 shown in FIG. 4 is mainly composed of a solid light source 10 that mainly emits light and a pedestal 20 on which the solid light source 10 is placed and fixed. In the case of a form, the solid light source which generate | occur | produces heat | fever by light emission, such as LED light source using a light emitting diode element, is employ | adopted.

  The pedestal 20 is provided with a light source installation part 20b for fixing the position of the solid light source 10, and the solid light source 10 is bonded to, fitted in, or placed on the light source installation part 20b. The position of the solid light source 10 is fixed to the base 20. Moreover, the light guide part 20a which spreads in the taper shape from the light source installation part 20b is formed, and plays the role which condenses the light emitted from the solid light source 10. The pedestal 20 can be mainly composed of a light-reflective metal material such as aluminum. The solid-state light source 10 includes a substrate and a light emitting element disposed on the substrate, and the substrate is disposed on the light source installation portion 20 b of the pedestal 20.

  On the other hand, the pedestal 20 has a predetermined digging portion 30 formed on the surface opposite to the mounting surface of the solid-state light source 10 (that is, the light source installation portion 20b). In the case of FIG. A trapezoidal island-shaped portion 30 a is formed, and the island-shaped portion 30 a has a shape protruding to the side opposite to the light emitting side of the solid light source 10. A spiral cooling pipe 40 is disposed in the digging portion 30 so as to surround the island-shaped portion 30a, and the solid light source 10 is cooled by a refrigerant (cooling fluid) flowing through the cooling pipe 40. The cooling is configured. That is, in this embodiment, the cooling pipe 40 is arrange | positioned along the digging shape of the base 20, and the contact area of the base 20 and the cooling pipe 40 is raised.

  Further, a filler (heat conducting material) 15 is filled in a gap between the dug portions 30 in which the cooling pipes 40 are disposed. This heat conduction material is filled with a silver paste and hardened, whereby a gap (air layer) between the cooling pipe 40 and the pedestal 20 is eliminated, and the cold heat from the cooling pipe 40 is transferred to the pedestal 20. It will be transmitted with high efficiency.

  Further, in the light source device 100 of the present embodiment, the refrigerant flow path of the cooling pipe 40 is covered with the heat insulating material 17, and the heat insulating material 16 is disposed between the refrigerant flow path and the flow return path. Has been. The heat insulating materials 17 and 16 can be formed by, for example, a foamed polypropylene tube or glass wool. In this case, it is possible to avoid problems such as the refrigerant being heated by the heat insulating material 17 before reaching the vicinity of the position where the solid light source 10 is disposed, and heat exchange with the heat generated from the solid light source 10 by the heat insulating material 16. It becomes possible to avoid problems such as heating of the refrigerant before heat exchange (refrigerant flowing in the forward path) by the subsequent refrigerant (refrigerant flowing in the return path).

  Here, a method for manufacturing the light source device 100 will be described. First, a metal aluminum base 20 as shown in FIG. 1 is prepared. The pedestal 20 is formed with a tapered cut, and the solid light source 10 is installed on the bottom surface (light source installation portion) 20b of the cut. The light guide 20a is formed by a tapered cut.

  Next, the digging portion 30 is formed on the pedestal 20 shown in FIG. Specifically, as shown in FIG. 2, digging is performed to form a truncated cone-shaped island 30 a on the light emitting back surface side of the solid light source 10. Then, a helical cooling pipe 40 as shown in FIG. 3 is formed and processed, and the cooling pipe 40 is formed in the digging portion 30 of the pedestal 20 shown in FIG. Are fitted and arranged in a manner surrounding the. Thereafter, the heat insulating materials 16 and 17 are disposed at predetermined positions as shown in FIG. 4, further filled with silver paste, and dried to obtain the light source device 100. In addition, since the solid light source 10 comprised from a light emitting diode element is about 1 mm square-2 mm square, it is suitable that the cooling pipe 40 shall be 0.5 mm or less in internal diameter and 1.0 mm or less in outer diameter, Such a shape can be formed by injection molding and bending technology.

  According to the light source device 100 having such a configuration, the cooling pipe 40 is disposed in the digging portion 30 of the pedestal 20 on which the solid light source 10 is placed, and the pedestal 20 is cooled indirectly by circulating the refrigerant therein. Thus, the solid light source 10 can be cooled. And since it is the structure which forms the digging part 30 in the base 20 and arrange | positions the cooling pipe 40 in it, the light source device 100 can be obtained very simply. Further, since the refrigerant is circulated on the surface opposite to the light source installation surface 20b of the solid light source 10, that is, on the side opposite to the light emitting surface, even when bubbles or the like are generated in the refrigerant, the optically It is not affected by bubbles.

  Further, since the cooling pipe 40 is arranged along the digging shape of the digging portion 30, the contact area between the island-like portion 30a of the digging portion 30 and the cooling pipe 40 becomes large, and the cooling efficiency is extremely high. It will be expensive. That is, by arranging the cooling pipe 40 along the digging shape, the digging surface of the pedestal 20 is efficiently cooled, and the solid light source 10 formed on the surface side of the digging portion 30 is also cooled with high efficiency. Will be. And since the helical cooling pipe 40 is arranged in a shape surrounding the island-like portion 30 of the pedestal 20 that protrudes on the opposite side to the light emission side of the solid light source 10 in particular, the pedestal 20 can be more efficiently operated. It becomes possible to cool, and as a result, the solid light source 10 formed on the surface side of the digging portion 30 can be further efficiently cooled.

  Further, since the gap between the cooling pipe 40 and the base 20 (digging portion 30) is filled with the filler 15 made of a heat conductive material, the air layer is eliminated as described above, and heat conduction is also performed in the gap portion. Thus, the cooling heat from the cooling pipe 40 is reliably transmitted to the pedestal 20, and the cooling pipe 20 can be firmly fixed in the digging portion 30.

  Hereinafter, modifications of the above embodiment will be described. FIG. 6 is a schematic cross-sectional view showing a light source device 200 according to a first modification, and is a drawing corresponding to FIG. 4 of the light source device 100. In the light source device 200, the digging portion 31 is formed on the back surface side of the light source installation portion 20b of the base 20, and the inverted frustoconical island portion 31a is formed. In addition, in the light source device 200, the components other than those described above have the same configuration for members / elements that have the same reference numerals as the light source device 100.

  Such a light source device 200 also has a high cooling ability with respect to the solid light source 10, but the cooling efficiency is slightly inferior to that of the light source device 100 described above, but particularly when forming the dug portion 31 of the base 20. Is simplified. That is, the light source device 200 can be obtained by forming a digging of the shape shown in FIG. 5 with respect to the pedestal 20 as shown in FIG. 1 and fitting the cooling pipe 40 into the digging portion 31. Since the digging shape is simplified as compared with the light source device 100 of FIG. 4, the manufacturing process is simplified.

  Further, the pedestal 20 shown in FIG. 1 is processed so as to form a cylindrical columnar portion 32a on the light emitting back surface side of the solid light source 10 as shown in FIG. 7, and a spiral cooling pipe is formed with respect to the columnar portion 32a. By fitting 40, the light source device 300 as a further different modification shown in FIG. 8 can be obtained. Also in this case, although the cooling efficiency is inferior to that of the light source device 100 shown in FIG. 4 or the light source device 200 shown in FIG. 6, the formation process of the dug portion 32 becomes simple. Further, in the configuration of the light source device 300, the cooling efficiency is improved when the forward path of the refrigerant is closer to the solid light source 10. Therefore, it is more preferable that the direction in which the coolant flows is opposite to that of the light source device 100.

(Projection type display device)
FIG. 9 is an enlarged view showing a schematic configuration of a projection display device as one embodiment of the present invention, and the projection display device 70 shown in FIG. 9 is an example of a three-plate system. In the projection type liquid crystal display device 70, an LED light source 100r including an LED element capable of emitting red (R) color light, an LED light source 100g including an LED element capable of emitting green (G) color light, and blue (B The three LED light sources 100b having LED elements capable of emitting colored light) are used as separate light sources. As each of the LED light sources 100r, 100g, and 100b, any of the light source devices 100, 200, and 300 of the various embodiments described above can be adopted, and a light guide unit 72 made of a rod lens or the like is provided on the emission side. Is arranged.

  A liquid crystal light valve 75 that modulates each color light of R, G, and B is provided on the emission side of each light guide 72. Then, the three color lights modulated by the respective liquid crystal light valves 75 are configured to enter a cross dichroic prism (color combining means) 77. This prism 77 is formed by bonding four right-angle prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a cross shape on the inner surface. These dielectric multilayer films combine the three color lights Lr, Lg, and Lb to form light representing a color image. The color synthesized light is projected onto the screen 79 by the projection lens 76, and an enlarged image is displayed.

  In such a projection type display device 70, any one of the light source devices 100, 200, 300 of the above embodiment is adopted for the LED light sources 100r, 100g, 100b, so that the light emission efficiency is high and the durability is high. And a display device with high reliability. Each LED light source 100r, 100g, 100b is provided with a cooling pipe 40 (see FIG. 4, FIG. 6, FIG. 8) through which the coolant flows, but the cooling pipe of each LED light source 100r, 100g, 100b is provided. A common pipe 35 is connected to each of the LED light sources 100r, 100g, and 100b in order to share the refrigerant that circulates 40. As a result, the refrigerant flowing through each LED light source 100r, 100g, 100b is shared, and the configuration of the cooling system is very simple.

  Although one embodiment of the present invention has been described above, the present invention is not limited to this, and the present invention is not limited to the wording of each claim without departing from the scope described in each claim. Improvements based on the knowledge that a person skilled in the art normally has can be added as appropriate to the extent that the person can easily replace them. For example, in the present embodiment, the configuration of the present invention is adopted for cooling the LED light source, but the configuration of the present invention can also be adopted for cooling other solid light sources, and the light source device of the present invention is a three-plate type. Although the embodiment adopted in the projection display device has been described, it is naturally possible to adopt the configuration of the light source device of the present invention in a single-plate projection display device.

The cross-sectional schematic diagram which shows the structure before a process about an example of the base which comprises the light source device of this invention. The cross-sectional schematic diagram which shows the example of 1 structure after the process of the base of FIG. The cross-sectional schematic diagram which shows an example of the cooling pipe which comprises the light source device of this invention. The cross-sectional schematic diagram which shows one Embodiment of the light source device of this invention. The cross-sectional schematic diagram which shows the example of a different structure after the process of the base of FIG. The cross-sectional schematic diagram which shows different embodiment of the light source device of this invention. The cross-sectional schematic diagram which shows the example of a different structure after the process of the base of FIG. The cross-sectional schematic diagram which shows different embodiment of the light source device of this invention. Explanatory drawing which shows schematic structure about one Embodiment of the projection type display apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Solid light source, 15 ... Filler (heat conduction material), 16, 17 ... Heat insulation material, 20 ... Base, 30, 31, 32 ... Excavation part, 30a, 31a ... Island-like part, 32a ... Columnar part, 40 ... Cooling pipe, 100, 200, 300 ... Light source device

Claims (10)

A solid light source, and a pedestal for placing the solid light source,
The pedestal is formed with a predetermined digging portion on a surface opposite to the mounting surface of the solid light source, and a cooling fluid for cooling the solid light source in the digging portion. A light source device characterized in that a cooling pipe through which the water flows is disposed.   The light source device according to claim 1, wherein the cooling pipe is disposed along a digging shape of the digging portion.   The said digging part is formed in the light emission back surface side of the said solid light source, and is provided with the island-shaped part protruded on the opposite side to the light emission side of this solid light source, The Claim 1 or 2 characterized by the above-mentioned. Light source device.   The said dug part is formed in the light emission back surface side of the said solid light source, The columnar part protruded on the opposite side to the light emission side of this solid light source is provided, The any one of Claim 1 thru | or 3 characterized by the above-mentioned. The light source device according to item.   5. The light source device according to claim 1, wherein the cooling pipe is formed in a spiral shape so as to surround the digging portion. 6.   The light source device according to any one of claims 1 to 5, wherein a gap between the dug portions in which the cooling pipes are disposed is filled with a heat conductive material.   The light source device according to any one of claims 1 to 6, wherein in the cooling pipe, the flow path of the cooling fluid is covered with a heat insulating material.   8. The light source device according to claim 1, wherein in the cooling pipe, a heat insulating material is disposed between a flow forward path and a flow return path of the cooling fluid.   A projection display device comprising the light source device according to claim 1.   A light source device according to claim 1, a light modulation device that modulates light emitted from the light source device, and a projection device that projects light modulated by the light modulation device. A projection type display device characterized by that.

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