JP4988912B2 - Projection display device - Google Patents

Description

  The present invention relates to a projection display apparatus having means for cooling a light source.

  The projection display apparatus is configured to use a halogen lamp as a light source and modulate and project the light emitted from the light source with a light valve such as a liquid crystal panel, and therefore needs to include a high-intensity light source. The heat generated from the high-intensity light source has disadvantages such as a decrease in light emission characteristics and a shortened life of the light source.

For this reason, conventionally, cooling light generated by a fan is blown to the light source to cool the light source, and air whose temperature has risen inside the casing of the apparatus is exhausted outside the casing (see Patent Document 1).
Japanese Patent Laid-Open No. 2001-2222065 JP 2005-338251 A JP 2005-257873 A International Publication No. 2005/064397 JP 2005-148707 A Japanese Patent Laying-Open No. 2005-099468 JP 2005-121890 A Japanese Patent Laid-Open No. 2001-230484 JP 2005-148694 A JP 2005-128563 A

  On the other hand, in recent years, development of a projection display apparatus using a solid light source such as an LED (Light-Emitting Diode) light source or an LD (Laser Diode) light source instead of a conventional halogen lamp as a light source has been advanced. . In such a projection-type image display device, the temperature range for efficiently emitting the solid-state light source is low, specifically, it is necessary to perform the light-emitting operation at about 100 ° C. or less. However, it is demanded more severely than a light source such as a conventional lamp.

  In view of the above circumstances, an object of the present invention is to realize a projection display apparatus that can cool a solid light source more efficiently.

  The present invention solves the above problems, and one feature of the present invention is that a first light source (for example, a blue LED element 61B) and a second light source (for example, a green LED) having different colors of emitted light. Element 61G) and a third light source (for example, red LED element 61R), a light modulating means (for example, liquid crystal panel 5) for modulating each of the emitted light based on a video signal and emitting video light, and the video Projection means (projection lens 6) for projecting light, first cooling means for cooling the first light source, and second cooling means for cooling the second light source and the third light source. In the projection display apparatus (projection display apparatus 10), the second light source and the third light source are provided close to each other, and the second cooling means includes the second light source and the third light source. The light source is cooled by a metal plate-like heat dissipation member It is characterized in.

  According to the present invention, light sources of various colors such as LEDs and lasers can be sufficiently cooled. In addition, it is possible to reduce the size of the second cooling means for cooling the second light source and the third light source.

  In the above projection display apparatus, the light modulation means may be a single plate type, and the third light source may be a red light source. According to such a projection display apparatus, the projection display apparatus can be reduced in size, weight, or cost. In addition, since the third light source and the second light source that generate the smallest amount of heat among at least three light sources are cooled by the same second cooling means, the light sources can be cooled more efficiently.

  Another feature of the present invention is that the first light source, the second light source, and the third light source having different colors of emitted light, a first cooling means for cooling the first light source, and the second light source And a second cooling means for cooling the third light source, the second light source and the third light source are provided close to each other, and the second light source is provided. The cooling means is characterized in that the second light source and the third light source are cooled by a metal plate-like heat radiating member.

  According to the present invention, in the projection display apparatus provided with the cooling means for cooling the LED light source, the cooling means includes the first cooling means for cooling the first light source among the three light sources, and other than the first light source. By separately providing the second light source and the second cooling means for cooling the third light source, each color LED light source can be efficiently cooled.

1 is a plan view of a projection display apparatus 10. 1 is a perspective view of a projection display apparatus 10. It is a figure which shows the structure of the light source part 11, (a) is a front view when it sees toward the z direction of FIG. 1, (b) is a front view when it sees toward the x direction of the figure. .

  Hereinafter, embodiments of the projection display apparatus of the present invention will be described.

  1 and 2 are diagrams showing a configuration of the projection display apparatus 10. 1 is a plan view, and FIG. 2 is a perspective view. The projection display apparatus 10 includes a plurality of light source units 11 (11R, 11G, 11B), a plurality of first rod integrators 41 (41R, 41G, 41B), and a plurality of second rod integrators 42 in a housing. (42R, 42G, 42B), a triangular prism 43, a plurality of liquid crystal panels 5 (5R, 5G, 5B), a dichroic prism 2, a projection lens 6, a pipe 12, and a plurality of radiators 14 (14a, 14b). And a plurality of blower fans 15 (15a, 15b). In the figure, reference numeral 20 denotes an electric circuit.

(Description of Optical System of Projection Display Device 10)
First, the optical system of the projection display apparatus 10 will be described. The light source unit 11 includes light source units 11R, 11G, and 11B, and includes a red LED element 61R that emits red light, a green LED element 61G that emits green light, and a blue LED light source 61B that emits blue light. The configuration of the light source unit 11 will be described in detail later with reference to FIG.

  The first rod integrator 41 is made of a resin such as glass or acrylic, and has a tapered shape in which the exit surface is larger than the entrance surface. The dispersion angle of the light beam incident on the first rod integrator 41 is reduced while being repeatedly reflected on the side surface. The second rod integrator 42 is made of a resin such as glass or acrylic, and has a prismatic shape in which the size of the exit surface is equal to (or substantially equal to) the entrance surface. The light beam incident on the second rod integrator 42 is emitted to the liquid crystal panel 5 as a uniform surface light source while being repeatedly reflected on the side surface. In the optical path from the light source unit 11G, there is a triangular prism 43 that is incident on the second rod integrator 42 while changing the traveling direction of the light emitted from the first rod integrator 41G by 90 °.

  The liquid crystal panel 5 modulates incident light based on a drive signal from a video signal generation circuit (not shown) and emits video light. Light emitted from the liquid crystal panel 5 (5R, 5G, 5B) is synthesized by the cross dichroic prism 2 and emitted to the projection lens 6. The projection lens 6 enlarges and projects the incident light onto a screen (not shown). The cross dichroic prism 2 has a property of reflecting red light and blue light incident from the incident surface and transmitting green light incident from the incident surface. Accordingly, the green light is incident on the cross dichroic prism 2 from the incident surface facing the exit surface (projection lens 6 side). Further, the dispersion angle of light incident on the projection lens 6 needs to be sufficiently small (for example, 15 degrees or less). Therefore, in order to achieve a sufficiently low dispersion angle, it is necessary to use a sufficiently long tapered first rod integrator 41.

(Description of the cooling system of the projection display apparatus 10)
Next, the cooling system of the light source unit 11 of the projection display apparatus 10 will be described. Referring to FIG. 1 (and FIG. 2), the cooling system is divided into a first cooling system that cools light source unit 11B and a second cooling system that cools light source units 11G and 11R.

  First, the structure of the light source unit 11 will be described with reference to FIG. The light source unit 11 includes an LED element 61, a heat conduction unit 63, a pipe connection unit 64, and a refrigerant channel 65. 3A is a view of the light source unit 11 (the light source unit 11G in FIG. 1) viewed from the front (minus z direction in FIG. 1), and FIG. 3B is a side view of the light source unit 11 (11G). It is the figure seen from the direction (minus x direction of FIG. 1). In addition, the arrow which shows the x, y, z direction of the figure respond | corresponds with the direction shown by the arrow of FIG.

  The heat conducting portion 63 is made of a metal having high heat conductivity such as copper. In addition, as shown in FIG. 3B, a refrigerant flow path 65 is formed in the heat conducting portion 63. The heat generated by the LED is thermally conducted to the refrigerant (water in the present embodiment) flowing through the refrigerant flow path 65 via the heat conducting portion 63. Then, the refrigerant flows to the pipe 12 through the outlet side of the pipe connecting portion 64. Thus, the light source unit 11 is cooled by the refrigerant.

  With reference to FIG. 1 (and FIG. 2) again, other components of the cooling system for cooling the light source unit 11 will be described.

  First, the first cooling system will be described. The refrigerant from the light source unit 11B travels through the pipe 12 toward the heat radiation fin (radiator) 14a. The pipe 12 is a resin (for example, rubber hose) or metal pipe. The radiating fin 14a cools the refrigerant whose temperature has risen in the light source unit 11B. The cooled refrigerant goes to the pump 13a. The pump 13a has a function of circulating the refrigerant of the first cooling system. The refrigerant goes to the light source unit 11B through the pump 13a. A blower fan 15a is provided on the back surface of the radiating fin 14a (a surface different from the surface on which the refrigerant inflow / outflow port is provided). The blower fan 15a sucks air in the housing and exhausts it toward the external region. The exhausted air efficiently removes heat from the cooling liquid in the radiating fins 14a, and the heat is discharged outside the casing.

  Next, the second cooling system will be described. The refrigerant from the light source unit 11R passes through the pipe 12 toward the light source unit 11G. The pipe 12 is a resin (for example, rubber hose) or metal pipe, as in the first cooling system. The refrigerant from the light source unit 11G travels through the pipe 12 toward the heat radiation fin (radiator) 14b. The heat radiation fin 14b cools the refrigerant whose temperature has risen in the light source units 11R and 11G. The cooled refrigerant goes to the pump 13b. The pump 13b has a function of circulating the refrigerant of the second cooling system. The refrigerant goes to the light source unit 11R through the pump 13b. A blower fan 15b is provided on the back surface of the radiating fin 14b (a surface different from the surface on which the refrigerant inflow / outflow port is provided). The blower fan 15b sucks air in the housing and exhausts it toward the external region. The exhausted air efficiently removes heat from the cooling liquid in the radiating fins 14b, and the heat is discharged out of the casing.

  The arrangement position of the pump 13 is not limited to the above configuration, and may be, for example, between the light source unit 11R and the light source unit 11G. Alternatively, the refrigerant may be circulated in the reverse direction to the above embodiment. For example, the refrigerant from the light source unit 11B may go from the pump 13a through the pipe 12 to the heat radiation fin 14a. However, a configuration in which the refrigerant from the light source unit 11 is directed to the pump 13 through the heat radiation fins 14 is preferable in that the temperature of the pump 13 does not increase.

  In the green light path, the second rod integrator 42G is provided between the triangular prism 43 and the liquid crystal panel 5, but the second rod integrator 42G may be omitted. Alternatively, an optical member in which the triangular prism 43 and the second rod integrator 42G are integrated may be employed.

(Function)
In this embodiment, the light source unit 11R generates the least amount of heat, the light source unit 11B generates the largest amount of heat, and the light source unit 11G is intermediate between them. Therefore, by separating the cooling system of the light source unit 11B from the cooling system of the light source units 11G and 11R, the light source units 11G and 11R can be sufficiently cooled. On the other hand, when the cooling system is not separated, the temperature of the refrigerant is raised exclusively by heat from the light source unit 11B, and the other light source units (11G, 11R) cannot be sufficiently cooled.

  In addition, a triangular prism 43 that bends the optical path by 90 degrees is provided in the optical path from the light source unit 11G. By providing this triangular prism 43 and bending the optical path, the space of the projection display apparatus 10 using the first rod integrator 41 as described above can be reduced. The triangular prism 43 is arranged so that the light incident surface is on the light source 11R side (not the light source 11B side). This is because the light source units 11G and 11R are provided close to each other. If the light sources 11G and 11R are provided close to each other, the length of the second cooling system pipe can be shortened, and the need for using a pump with a large output is eliminated.

  On the other hand, when such bending is not performed, the distance between the light sources becomes long. Therefore, if a plurality of light sources are cooled by one cooling system, the piping becomes long and the apparatus becomes heavy. In addition, it is necessary to use a pump with a large output.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  In the said embodiment, it isolate | separates into the 1st cooling system which cools a blue light source, and the 2nd cooling system which cools the light source of another color. However, the present invention is not simply characterized by separating blue from green and red, but is divided by two cooling means to cool three light sources. Depending on the characteristics of the light source employed, the cooling system for light sources other than blue may be separated from the cooling system for other color light sources. For example, it may be separated into a first cooling system that cools the light source with the second largest heat generation amount and a second cooling system that cools the light sources of other colors with the first and third largest heat generation amounts. .

  It should be noted that the heat generation amount of the light source referred to above is the heat generation amount accompanying the output from the light source necessary for displaying predetermined video light. The calorific value is measured, for example, by measuring the temperature around the light source.

  The light source cooling system of the above embodiment is cooled using a refrigerant, but may be one that does not use a refrigerant. For example, a red light source and a green light source may be provided close to each other, and these may be cooled by a common cooling member (for example, a metal plate-like heat radiating member) having high thermal conductivity. Moreover, although the said embodiment is related with the 3 plate type projection type video display apparatus provided with three liquid crystal panels, you may apply this invention to a single plate type projection type video display device. In this case, the liquid crystal panel is arranged at a position after color synthesis by the cross dichroic prism 2.

  In the above embodiment, the light from the light source with the largest calorific value is incident from the incident surface not facing the exit surface of the cross dichroic prism 2, but instead, the light from the light source with the largest calorific value is incident. Alternatively, the light may be incident from an incident surface facing the exit surface of the cross dichroic prism 2. At this time, the integration means for guiding light to the incident surface of the cross dichroic prism 2 is bent toward the light source that generates the smallest amount of heat. For example, in the projection display apparatus 10 configured as shown in FIG. 1, when the green LED light source has the largest amount of heat generation, the red LED light source has the second largest amount, and the blue LED light source has the smallest amount of heat generation, The integrator for the green LED light source may be bent toward the blue LED light source.

(Industrial applicability)
In the above embodiment, an LED light source has been described as a light source. However, a light source that requires stricter heat countermeasures than a conventional lamp light source is not limited to an LED light source. As a light source that can use the present invention in addition to the LED light source, a so-called rollover phenomenon occurs depending on the environmental temperature, and there is a possibility that the resin is yellowed due to the LD light source in which the light emission efficiency decreases or the environmental temperature. For this reason, a light source molded by a resin can be used. In addition, the light source is not necessarily composed of one light emitting element, but there is also a light source configured by arraying a plurality of light emitting elements. In this case, the total heat generation amount from the plurality of light emitting elements should be considered. is there.

  The heat conduction part has been described using a copper plate having high heat conductivity. However, in order to improve the responsiveness of the cooling system (improve the cooling capacity), a heat transferable member such as a Peltier element is provided in the heat conduction part. By providing, heat generated from the light source can be absorbed from the light source in a shorter time.

  DESCRIPTION OF SYMBOLS 2 ... Dichroic prism, 5 ... Liquid crystal panel, 6 ... Projection lens, 10 ... Projection type image display apparatus, 11 ... Light source part, 12 ... Pipe, 13 ... Pump, 14 ... Radiation fin (radiator), 15 ... Blower fan, 20 DESCRIPTION OF SYMBOLS ... Electric circuit, 41 ... 1st rod integrator, 42 ... 2nd rod integrator, 43 ... Triangular prism, 61 ... LED element, 63 ... Heat conduction part, 64 ... Pipe connection part, 65 ... Refrigerant flow path.

Claims (4)

A first light source, a second light source, and a third light source having different colors of emitted light; light modulating means that modulates each emitted light based on a video signal and emits video light; and In a projection display apparatus comprising: projection means for projecting; first cooling means for cooling the first light source; and second cooling means for cooling the second light source and the third light source.
The second light source and the third light source are provided close to each other,
The projection type image display apparatus, wherein the second cooling means cools the second light source and the third light source by a metal plate-like heat radiating member. The projection display apparatus according to claim 1, wherein
A projection display apparatus characterized in that the light modulation means is a single plate type. The projection display apparatus according to claim 1 or 2,
The projection display apparatus, wherein the third light source is a red light source. The first light source, the second light source, and the third light source having different colors of the emitted light, the first cooling means for cooling the first light source, and the second light source and the third light source are cooled. A light source device for a projection display apparatus, comprising: a second cooling means that:
The second light source and the third light source are provided close to each other,
The light source apparatus for a projection display apparatus, wherein the second cooling means cools the second light source and the third light source by a metal plate-like heat radiating member.

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