Light source apparatus and projector

A light source apparatus includes a first light source, a second light source, a first radiator configured to hold the first light source and to radiate heat from the first light source, and a second radiator configured to hold the second light source and to radiate heat from the second light source. The first radiator includes a plurality of first radiating members to be cooled by air introduced from a first direction and superposed in a second direction. The second radiator includes a plurality of second radiating members to be cooled by air introduced from the first direction and superposed in a third direction. Each of the second direction and the third direction is orthogonal to the first direction. The second direction and the third direction are different from each other.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a light source apparatus and a projector including the light source apparatus.

Description of the Related Art

Japanese Patent Laid-Open No. (“JP”) 2013-114980 discloses a light source apparatus that includes a first light source unit having a plurality of first solid-state light sources and a second light source unit having a plurality of second solid-state light sources, wherein emission directions of the first light source unit and the second light source unit are orthogonal to each other in order to achieve the high luminance and compact structure. JP 2014-139659 discloses a light source apparatus that cools a light source unit using a cooling member such as a heat sink.

The emission directions of the two light source units are orthogonal to each other in the light source apparatus disclosed in JP 2013-114980. Thus, in an attempt to dispose the heat sink disclosed in JP 2014-139659 in the light source apparatus disclosed in JP 2013-114980, the heat sinks attached on the sides opposite to the emission directions of the respective light source units are also orthogonal to each other. As a result, in an attempt to efficiently blow cooling air to the heat sinks, the wind direction vectors of the cooling air for the two light source units are also orthogonal to each other, which makes complicated the internal configuration of the light source apparatus and the airflows. In addition, when outside air is directly blown for efficient cooling, the projector housing that houses two light source units needs two or more inlets, and the installation performance is restricted so as to prevent the inlets from being blocked.

SUMMARY OF THE INVENTION

The present invention provides a light source apparatus and a projector, each of which can be efficiently cooled by a unidirectional airflow.

A light source apparatus according to one aspect of the present invention includes a first light source, a second light source, a first radiator configured to hold the first light source and to radiate heat from the first light source, and a second radiator configured to hold the second light source and to radiate heat from the second light source. The first radiator includes a plurality of first radiating members to be cooled by air introduced from a first direction and superposed in a second direction. The second radiator includes a plurality of second radiating members to be cooled by air introduced from the first direction and superposed in a third direction. Each of the second direction and the third direction is orthogonal to the first direction. The second direction and the third direction are different from each other. A projector having the above light source apparatus also constitutes another aspect of the present invention.

DESCRIPTION OF THE EMBODIMENTS

Referring now to the accompanying drawings, a description will be given of embodiments according to the present invention.

First Embodiment

Referring now toFIGS. 1 to 4, a description will be given of a light source apparatus according to a first embodiment of the present invention.FIG. 1explains of a cooling structure in a light source apparatus10according to this embodiment.FIG. 2explains a light beam and a structure of the light source apparatus10.FIG. 3is a sectional view taken along a line A-A inFIG. 2.FIG. 4is a sectional view taken along a line B-B inFIG. 2.

As illustrated inFIGS. 1 and 2, the light source apparatus10includes a first light source unit1, a second light source unit2, and a combining unit3. The first light source unit1includes a first light source11having a plurality of solid-state light sources that emit laser beams (LD beams), and a first radiator12that holds the first light source11and radiates heat from the first light source11. The second light source unit2includes a second light source21having a plurality of solid-state light sources that emit LD beams, and a second radiator22that holds the second light source21and radiates heat from the second light source21. The first light source11emits the LD beam in the Y direction. The second light source21emits the LD beam in the X direction. Thus, in this embodiment, the emission direction of the first light source11and the emission direction of the second light source21are orthogonal to each other, but the present invention is not limited to this embodiment.

The combining unit3combines the light from the first light source11and the light from the second light source21with each other. Light transmitting areas and light reflecting areas made of the reflective film are alternated in the combining unit3. InFIGS. 1 and 2, light110from the first light source11is reflected by the reflective film in the combining unit3, and light210from the second light source21transmits through the light transmitting area. The light from the first light source11travels in the same direction (X direction) as that of the light from the second light source21. The emission direction of the first light source11and the emission direction of the second light source21are orthogonal to each other. The first emission direction and the second emission direction may be combined at a specific angle.

The first radiator12conducts or radiates the heat generated using a plurality of solid-state light sources as heat sources. The first radiator12is held in contact with the light source11via grease (not shown). The second radiator22is held in contact with the light source21via grease (not shown). In this embodiment, the first radiator12is disposed relative to the first light source11, and the second radiator22is disposed relative to the second light source21. The first radiator12includes a base portion (first holder)121that contacts the light source11through grease, and a plurality of fin portions (a plurality of radiating members)122coupled to the base portion121and configured to maintain the shape and to radiate the heat. Similarly, the second radiator22includes a base portion (second holder)221that contacts the light source21via grease, and a plurality of fin portions (a plurality of radiating members)222coupled to the base portion20021and configured to maintain the shape and to radiate the heat. The first radiator12and the second radiator22have an effect of efficiently radiating the heat from the light sources11and21at the base portions121and221and an effect of efficiently conducting the heat to the fin portions122and222, and includes a plurality of heat pipes123and223for increasing the cooling capacity.

Thus, according to this embodiment, the first radiator12includes a plurality of fin portions122superposed in the second direction (first superposing direction: X direction) so as to be cooled by air introduced from the first direction (Y direction). The second radiator22has a plurality of fin portions222superposed in the third direction (second superposing direction: Z direction) so as to be cooled by air introduced from the first direction. Each of the second direction and the third direction is orthogonal to the first direction. In this embodiment, the second direction and the third direction are orthogonal to each other, but the present invention is not limited to this embodiment, and the second direction and the third direction may be different from each other.

In this embodiment, the first light source unit1is an integrated unit including the first light source11and the first radiator12. The second light source unit2is an integrated unit including the second light source21and the second radiator22. In this embodiment, the first light source11and the second light source21may be semiconductor light sources of indium gallium nitride (B light). Alternatively, the first light source11may be a semiconductor light source of aluminum gallium arsenide (R light), and the second light source21may be a semiconductor light source of indium gallium nitride (B light).

Solid arrows100and200illustrated inFIG. 1indicate flows of air (cooling air) to the first light source unit1and the second light source unit2. The fan41blows cooling air on the first radiator12and the fan42blows cooling air on the second radiator22, thereby cooling the first light source11and the second light source21.

Referring now toFIGS. 1, 3, and 4, a description will be given of a cooling configuration. In the first radiator12, the plurality of fin portions122are superposed or stacked in the X direction. In the second radiator22, the plurality of fin portions222are superposed or stacked in the Z direction. In this embodiment, the first radiator12and the second radiator22have the same shape, and the cost can be reduced by using common components.

The solid arrow100inFIG. 3indicates the flow of the cooling air for the first light source unit1. The solid arrow200inFIG. 4indicates the flow of the cooling wind for the second light source unit2. The fan41that cools the first radiator12is disposed in the − (minus) Y direction relative to the first radiator12and blows the cooling air in the Y direction. The fan42that cools the second radiator22is also disposed in the −Y direction relative to the second radiator22and blows cooling air in the Y direction. As illustrated inFIG. 3, in the first radiator12, cooling airflows in the Y direction, passes among the plurality of fins122, collides with the base portion121, and flows in the Z and −Z directions and then in Y direction. As illustrated inFIG. 4, in the second radiator22, the cooling air flows in the Y direction, passes among the plurality of fin portions222, and flows in the Y direction as it is. The stacking or superposing direction of the plurality of fin portions122in the first radiator12and the stacking or superposing direction of the plurality of fins222in the second radiator22may tilt as long as they do not remarkably obstruct the cooling airflows.

Referring now toFIGS. 5, 6A, and 6B, a description will be given of a projector (image projection apparatus)500including the light source apparatus10according to this embodiment.FIG. 5illustrates a structure of the projector500.FIGS. 6A and 6Bare perspective views of the projector500, andFIGS. 6A and 6Bare figures viewed from different directions. Solid arrows inFIGS. 5, 6A, and 6Brepresent cooling airflows passing through the first light source unit1and the second light source unit2.

The housing5that forms the appearance of the projector500includes an upper housing member and a lower housing member (not shown). The housing5that houses the first light source unit1and the second light source unit2(or the light source apparatus100) has a first inlet51and a second inlet52for taking in the cooling air to the first radiator12and the second radiator22in the housing5. The first inlet51takes in air for cooling the plurality of fin portions122. The second inlet52takes in air for cooling the plurality of fin portions222. Thus, the first inlet51and the second inlet52correspond to the first radiator12and the second radiator22, respectively. The first inlet51and the second inlet52are formed on the same surface of the housing5. In this embodiment, the first inlet51and the second inlet52are the same inlet, but the present invention is not limited to this embodiment. An exhaust fan43is disposed in the housing5. An outlet53is provided in a surface different from the surface on which the first inlet51and the second inlet52of the housing5are provided, for example, on the opposite surface, and used to exhaust the internal heat.

Disposed inside the housing5of the projector500are a light source unit6(corresponding to the light source apparatus10) including the first light source unit1and the second light source unit2, an illumination optical system71, a color separation and combination optical system72, and the projection lens8. The light source unit6has a phosphor (fluorescent object) that converts the wavelength of light from each of the first light source11and the second light source21into a wavelength band different from that of incident light, and emits the light. The inside of the light source unit6has a dust-proof sealed structure. The phosphor is applied in an annular shape using a metal wheel, and the wheel is attached to a motor and rotated.

The light from the light source unit6illustrates the color separation and combination optical system72via the illumination optical system71. The illumination optical system71has a glass member such as a cylinder array, and a plurality of light beams form a rectangular uniform illumination area while rectangular images are superimposed. The illumination optical system71has an optical sensor and detects a red (R) light amount, a green (G) light amount, and a blue (B) light amount for minute leaked light or transmission light in the illumination optical system71. The color separation and combination optical system72separates the P-polarized light and S-polarized light divided by the illumination optical system71into the R, G, and B colored light. Image forming elements73r,73g, and73bprovided for the respective R, G, and B colors reflect light and perform image modulations to form images. Again, the light combined by the optical element that combines the R, G, and B light beams is irradiated onto the projection lens (optical element)8. The projection lens8magnifies the irradiated light (image) and changes the focus, so that the image is projected on the screen as a projection surface. In the housing5, an electric board9is disposed for driving the projector, such as supplying power to the light source unit6and processing signals to the image forming elements73r,73g,73b. In this way, the projector500has the image forming elements73r,73g, and73bthat form images based on the light emitted from the light source apparatus10and the projection lens8that magnifies and projects the images formed by the image forming elements73r,73g, and73b.

Referring now toFIGS. 1 to 6B, a description will be given of the effects of this embodiment. In the prior art configuration, since the radiator is disposed on the surface opposite to the emission direction with respect to the light source, the fan for cooling the light source is often disposed on the extension of the light source and the radiator. Such a configuration creates complicated airflows by making the blowing wind directions to the first light source unit and the second light source unit including the first light source and the second light source substantially orthogonal to each other. In addition, the blowing channel and the structure for not obstructing the blowing airflows become complicated and large.

When the radiator of the first light source unit and the radiator of the second light source unit are disposed near the inlets in the housing in order to improve the cooling efficiency, it is necessary to separately provide the housing with the inlet for the first light source unit and the inlet for the second light source. Hence, it is necessary to use two surfaces out of the six surfaces constituting the housing for the inlets. Since the inlet takes in the cooling air for the projector, it is necessary to avoid an obstacle or high-temperature intake outside the inlet to some extent. Thus, there are restrictions in the installation environment for the user.

When the fin portions in the first radiator and the fin portions in the second radiator are both stacked in the Z-axis direction, the inlets in the housing can be arranged on a single surface. However, the cooling effect may be prevented, such as the wind that has passed through the first radiator obstructing the intake for the second radiator, the wind after the heat exchange being taken in, or the second radiator obstructs the exhaust channel.

The configuration according to this embodiment can set the direction of the cooling air to the first radiator12and the direction of the cooling air to the second radiator22to the same direction (Y direction), and set the winds that have passed through the first radiator12and the second radiator22to the same direction (Y direction). Thus, an efficient airflow is made in the housing5. Since the first inlet51and the second inlet52can also be disposed on the one surface of the housing5, it is possible to relieve the restrictions on the installation environment for the user. Since the inlets51and52can be provided to the same surface, a single fan can be substituted for the fans41and42, and the size and cost can be reduced.

Next follows a description of the cooling efficiency according to this embodiment. In the first radiator12, the cooling air impinges on the base portion121(from the Y direction to the Z and −Z directions), so that the boundary layer between the object and the fluid can be made thinner and the cooling efficiency becomes high.

By increasing a length L2of the fin portion222in the second radiator21inFIG. 2in the X direction, it is possible to increase an area of the channel section (XZ plane) from the inlet52. As a result, the system resistance of the fluid can be lowered, the contact surface area between the fin portion222and the cooling air can be made larger, and thus the cooling ability can be improved.

As illustrated inFIG. 3, assume that L1is a length of the base portion121in the first radiator12in a direction (such as the Z direction) orthogonal to each of a first direction (such as the Y direction) and a second direction (such as the X direction). As illustrated inFIG. 2, assume that L2is a length of the fin portion222in the second radiator22in a direction (such as the X direction) orthogonal to each of the first direction (such as the Y direction) and the third direction (such as the Z direction). Then, the length L2is longer than the length L1(L2>L1). Thereby, the height direction (Z direction) of the housing5can be suppressed, so that the housing5can be made smaller in the height direction while the cooling ability is maintained.

The first radiator12is configured such that the length of the fin portion122in the Z direction is longer than the length L1of the base portion121in the Z direction. Thereby, the wind after passing through the first radiator12can be easily guided in the Y direction, and the fluid system resistance by the base portion121can be reduced. Thus, it is possible to increase the flow velocity passing through the fin portion122and to improve the cooling ability.

As illustrated inFIG. 2, part of the fin portion222in the second radiator is disposed on the projection plane (S1area) of the base portion121in the first radiator12in the −X direction. Thereby, a space generated between the first radiator12and the second radiator22can be used as a cooling unit, and the cooling ability can be enhanced.

As illustrated inFIGS. 5, 6A, and 6B, air is taken in through the first inlet51and the second inlet52disposed in the housing surface in the direction (−Y direction) in which light is emitted from the projection lens8, and the air is exhausted through the outlet53disposed in the housing surface in the direction (Y direction) opposite to the light emission direction of the projection lens8. Thereby, the linear airflow in the housing5allows the efficient intake and exhaust.

A multi-projection method, a stack projection method, and the like are known in which multiple images are combined to make them larger by disposing multiple housings, or by superimposing them to make them brighter. In the above projection method, the first inlet51, the second inlet52, and the outlet53are linearly arranged on the surface in the Y direction, so that the intakes and exhausts of the housings are less influential although a plurality of housings are arranged close to each other. This configuration can relieve the installation restrictions for the user and restrain the thermal runaway of the housing.

Second Embodiment

Referring now toFIG. 7, a description will be given of a light source apparatus according to a second embodiment of the present invention.FIG. 7explains a cooling structure of a light source apparatus10aaccording to this embodiment. The light source apparatus10aaccording to this embodiment is different from the light source apparatus10according to the first embodiment in having a first radiator120and a second radiator220in place of the first radiator12and the second radiator22. The other configuration, system, and cooling airflow of the light source apparatus10aare the same as those of the light source apparatus10according to the first embodiment, and thus a description thereof will be omitted.

As illustrated inFIG. 7, the first radiator120includes a base portion1201, fin portions1202, and a heat pipe1203. The second radiator220has a base portion2201, fin portions2202, and a heat pipe2203. In addition, the solid arrow inFIG. 7represents the cooling wind flows of the first radiator120and the second radiator220.

The first radiator120maintains a large area for a channel section (XZ plane) of the first fan41and a small area for the channel (Y direction) of the fin portion1202to improve the cooling performance. The second radiator220is configured such that the fin portion2202of the second radiator220is disposed at the portion of the complex angle (area S2) generated between the first radiator120and the second radiator220. As described above, in this embodiment, part of the fin portion2202in the second radiator220is disposed on the projection surface of the fin portion1202in the first radiator120in the X direction (second direction). This configuration increases the contact surface area with the cooling air, and enhances the cooling ability. Due to the above effect, the cooling ability is improved, and the size can be reduced by the efficient arrangement.

In addition, the second radiator220is disposed close to the direction (−Y direction) of the fan42. Thereby, the fan44can be disposed closer to the Y direction than the second radiator220. By disposing the radiator220between the fans42and44, the static pressure of the wind passing through the fin portion2202in the second radiator220can made larger, so that the flow velocity can be made higher and the cooling ability can be improved.

Each embodiment can provide a light source apparatus and a projector, each of which can be efficiently cooled by a unidirectional airflow.

This application claims the benefit of Japanese Patent Application No. 2019-132435, filed on Jul. 18, 2019, which is hereby incorporated by reference herein in its entirety.