JP2015059995A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for improving durability of a light-emitting element.SOLUTION: An image projection unit of an image display device includes a first light source, a second light source and a third light source which emit light for generating image display light based on an image signal. A first heat sink 120a is provided outside a housing 110 and is connected to the first light source. A second heat sink 120b is provided outside the housing 110 and is connected to the second light source. A third heat sink 120c is provided outside the housing 110 and is connected to the third light source. A distance from the first heat sink 120a to the second heat sink 120b and a distance from the first heat sink 120a to the third heat sink 120c are longer than a distance from the second heat sink 120b to the third heat sink 120c.

Description

  The present invention relates to an image display device.

  A display device called a head-up display is known. The head-up display is a display device that is installed in, for example, an automobile or an aircraft and displays information superimposed on an actual landscape. When the head-up display is installed in a vehicle of a car, the driver can recognize the information of the image projected from the optical unit with almost no change in the line of sight or focus while visually recognizing the scenery outside the vehicle. In recent years, it has attracted attention as a display device for use.

  As a light source of a display device, a plurality of light emitting elements such as a red light emitting diode, a green light emitting diode, and a blue light emitting diode may be used. In order to dissipate the heat of these light emitting elements, a technique of attaching a heat sink to the back surface of the substrate on which the light emitting elements are arranged is disclosed (for example, see Patent Document 1).

JP 2004-341554 A

  When a plurality of light-emitting elements are used as the light source, the heat-resistant temperature may be different among the light-emitting elements depending on the light-emitting element used. When a plurality of light-emitting elements having different heat-resistant temperatures are radiated, heat from a light-emitting element is transferred to a light-emitting element having a heat-resistant temperature lower than that of the light-emitting element, thereby reducing the durability of the light-emitting element. sell.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a technique for improving the durability of a light-emitting element.

  In order to solve the above problems, an image display device according to an aspect of the present invention includes an image including a first light source, a second light source, and a third light source that emit light for generating image display light based on an image signal. A projection unit, a housing that houses the image projection unit inside, a first heat sink that is provided outside the housing and connected to the first light source, and is provided outside the housing and connected to the second light source A second heat sink, and a third heat sink that is provided outside the housing and is connected to the third light source. Both the distance from the first heat sink to the second heat sink and the distance from the first heat sink to the third heat sink are longer than the distance from the second heat sink to the third heat sink.

  According to the image display device of the present invention, it is possible to provide a technique for improving the durability of the light emitting element.

It is a figure which shows typically the installation aspect of the head-up display which concerns on embodiment of this invention. It is a figure which shows the internal structure of an optical unit. It is a figure which shows typically the internal structure of an image projection part. It is a figure which shows the optical path of the image display light projected on a windshield. FIGS. 5A to 5B are views showing the appearance of the image projection unit according to the embodiment. It is a figure which shows the case where the bottom face of the housing | casing of the optical unit which concerns on embodiment is observed from the outer side. It is a figure which shows the case where the bottom face of the housing | casing of the optical unit which concerns on embodiment is observed from the outer side in the state which removed the 1st heat sink. It is a figure which shows the 1st heat sink of the state removed from the housing | casing. It is a figure which shows the case where it observes from the front side of a housing | casing in the state which attached the 1st heat sink to the housing | casing of the optical unit. It is a figure which shows the heat sink and each light source which concern on the 1st modification of embodiment. FIGS. 11A and 11B are enlarged views showing the connecting portions of the deformable members in the heat sink according to the first modified example of the embodiment. It is a figure which shows the heat sink and each light source which concern on the 2nd modification of embodiment. It is a figure which shows the heat sink and each light source which concern on the 3rd modification of embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. Specific numerical values and the like shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  As an image display device according to an embodiment, a head-up display 10 that is installed and used in a dashboard of a vehicle will be described as an example. FIG. 1 is a diagram schematically showing an installation mode of a head-up display 10 according to an embodiment of the present invention. The head-up display 10 includes an optical unit 100 and a control device 50. FIG. 1 is a diagram showing a case where an optical unit 100 is used in a dashboard on the left side with reference to the traveling direction of the vehicle (left direction in FIG. 1). The following embodiment is a left-hand drive vehicle. The example in which the head-up display 10 is arranged for the driver in FIG. In addition, since it is for right-hand drive vehicles, the internal configuration of the optical unit 100 may be reversed left and right with reference to the traveling direction of the vehicle. Hereinafter, an outline of the head-up display 10 will be described with reference to FIG.

  The control device 50 includes a CPU (Central Processing Unit) (not shown), and generates an image signal to be displayed on the optical unit 100. The control device 50 also includes an external input interface (not shown), which receives an image signal output from an external device such as a navigation device or a media playback device, and performs a predetermined process on the input signal. Thereafter, it can be output to the optical unit 100.

  The optical unit 100 generates image display light to be displayed as a virtual image 450 on the windshield 610 based on the image signal generated by the control device 50. Therefore, the optical unit 100 includes an image projection unit 210, an intermediate mirror 350, an intermediate image formation unit 360, and a projection mirror 400 inside the housing 110.

  The image projection unit 210 houses a light source, an image display element, various optical lenses, and the like. The image projection unit 210 generates and projects image display light based on the image signal output from the control device 50. In the present embodiment, a case where LCOS (Liquid crystal on silicon) which is a reflective liquid crystal display panel is used as an image display element is illustrated.

  The image display light projected by the image projection unit 210 is reflected by the intermediate mirror 350. The image display light reflected by the intermediate mirror 350 forms an image on the intermediate image forming unit 360. The image display light related to the real image formed by the intermediate image forming unit 360 is transmitted through the intermediate image forming unit 360 and projected onto the projection mirror 400.

  The projection mirror 400 is a concave mirror, and the image display light transmitted through the intermediate image forming unit 360 is enlarged by the projection mirror 400 and projected onto the windshield 610. The image display light projected on the windshield 610 is changed to an optical path toward the user by the windshield 610. The user E who is a driver recognizes the image display light reflected by the windshield 610 as a virtual image 450 ahead of the windshield 610 in the line-of-sight direction.

  FIG. 2 is a diagram showing an internal configuration of the optical unit 100 according to the embodiment of the present invention. Hereinafter, the internal configuration of the optical unit 100 will be described with reference to FIG.

  As described above, the optical unit 100 includes the image projection unit 210, the intermediate mirror 350, the intermediate image formation unit 360, and the projection mirror 400 inside the housing 110. Although details will be described later, the image projection unit 210 includes three different light sources that respectively generate red, green, or blue light. The light source can be realized by using an LED (Light Emitting Diode) or a semiconductor laser light source. In this embodiment, a case where an LED is used as the light source will be described.

  The light source generates heat during use. For this reason, the optical unit 100 includes a heat sink for cooling the light source. Since there are three types of light sources, in order to cool the light sources, a heat sink 120a connected to the red light source, a heat sink 120b (not shown) connected to the green light source, and the outside of the housing 110 of the optical unit 100, A heat sink 120c connected to the blue light source is provided.

  The case 110 is aluminum die-cast. Here, both the heat sink 120b and the heat sink 120c for radiating the blue light source and the green light source are configured integrally with the housing 110, respectively. On the other hand, the heat sink 120a for cooling the red light source is installed at a location spatially separated from the heat sink 120b and the heat sink 120c, and is externally attached separately from the housing 110. For this reason, the heat generated by the red light source is carried to the heat sink 120a via the heat pipe 25.

  Next, the optical system of the head-up display 10 will be described with reference to FIGS. FIG. 3 is a diagram schematically showing the internal configuration of the image projection unit 210 together with the optical path of the image display light. FIG. 4 is a diagram illustrating an optical path of image display light projected onto the windshield 610 via the intermediate mirror 350, the intermediate image forming unit 360, and the projection mirror 400.

  First, the internal configuration of the image projection unit 210 will be described with reference to FIG. The image projection unit 210 includes illumination units 230a, 230b, and 230c (hereinafter also collectively referred to as illumination units 230), a dichroic cross prism 244, a reflector 236, a field lens 237, a polarization beam splitter 238, a phase difference plate 239, and an analyzer. 241 and a projection lens group 242. In FIG. 3, the description of the internal configurations of the first illumination unit 230a and the third illumination unit 230c is omitted, and only the internal configuration of the second illumination unit 230b is shown, but each illumination unit 230 has the same configuration. .

  The illumination unit 230 includes a light source 231, a collimator lens 232, a UV-IR (UltraViolet-Infrared Ray) cut filter 233, a polarizer 234, and a fly-eye lens 235. The light source 231 includes a light emitting diode that emits light of any one of red, green, and blue. The 1st illumination part 230a has a light emitting diode which emits red light as a light source. The 2nd illumination part 230b has a light emitting diode which emits green light as the light source 231. The 3rd illumination part 230c has a light emitting diode which emits blue light as a light source.

  The light source 231 is attached to the light source attachment portion 243. The light source mounting portion 243 is thermally coupled to a heat sink (not shown), and dissipates heat generated when the light source 231 emits light. The light emitted from the light source 231 is converted into parallel light by the collimating lens 232. The UV-IR cut filter 233 absorbs and removes ultraviolet light and infrared light from the parallel light that has passed through the collimating lens 232. The polarizer 234 changes the light that has passed through the UV-IR cut filter 233 into unpolarized P-polarized light. The fly-eye lens 235 uniformly adjusts the brightness of the light that has passed through the polarizer 234.

  Light transmitted through the fly-eye lens 235 of each illumination unit 230 is incident on the dichroic cross prism 244 from different directions. The red, green, and blue light incident on the dichroic cross prism 244 becomes white light that is a combination of the three colors and travels toward the reflecting mirror 236. The reflecting mirror 236 changes the optical path of the white light synthesized by the dichroic cross prism 244 by 90 degrees. The light reflected by the reflecting mirror 236 is collected by the field lens 237. The light collected by the field lens 237 is irradiated to the image display element 240 via the polarization beam splitter 238 and the phase difference plate 239 that transmit the P-polarized light.

  The image display element 240 includes red, green, and blue color filters for each pixel. The light emitted to the image display element 240 has a color corresponding to each pixel, is modulated by the liquid crystal composition included in the image display element 240, and becomes S-polarized image display light toward the polarization beam splitter 238. Emitted. The emitted S-polarized light is reflected by the polarization beam splitter 238, changes its optical path, passes through the analyzer 241, and then enters the projection lens group 242. The image display light transmitted through the projection lens group 242 exits the image projection unit 210 and enters the intermediate mirror 350.

  Next, the optical path of the image display light projected from the intermediate mirror 350 onto the windshield 610 via the intermediate image forming unit 360 and the projection mirror 400 will be described with reference to FIG. The optical path of the image display light emitted from the projection lens group 242 of the image projection unit 210 is changed to an optical path toward the projection mirror 400 by the intermediate mirror 350. On the way, a real image based on the image display light reflected by the intermediate mirror 350 is formed by the intermediate image forming unit 360.

  The intermediate image forming unit 360 includes a diffusion screen 362 and a concave lens 364. The diffusion screen 362 forms a real image based on the image display light transmitted through the intermediate image forming unit 360 and controls the orientation angle ψ of the image display light toward the projection mirror 400. The concave lens 364 controls the principal ray direction of the image display light traveling toward the projection mirror 400 and adjusts the angle θ formed by the image display light before and after passing through the intermediate image forming unit 360.

  The image display light transmitted through the intermediate image forming unit 360 is reflected by the projection mirror 400 and projected onto the windshield 610. The image display light projected on the windshield 610 is changed to an optical path toward the user by the windshield 610. Thereby, the user can visually recognize the virtual image based on the image display light forward through the windshield 610 as described above.

  With the above configuration, the user can visually recognize the virtual image based on the image signal output from the control device 50 by superimposing it on the actual landscape via the windshield 610.

  Next, heat dissipation in the optical unit 100 according to the embodiment will be described.

  FIGS. 5A and 5B are views showing the appearance of the image projection unit 210 according to the embodiment. Specifically, FIG. 5A is a diagram illustrating an external appearance when the image projection unit 210 is viewed from the right side in the projection direction of the image projection unit 210. FIG. 5B is a diagram illustrating an external appearance when the image projection unit 210 is viewed from the left side in the projection direction of the image projection unit 210.

  As described above, there are three illumination units 230: a first illumination unit 230a, a second illumination unit 230b, and a third illumination unit 230c that emit light of each color of red, green, and blue. FIG. 5A shows a light source attachment portion 243 in the first illumination section 230a and a light source attachment section 243 in the second illumination section 230b. On the other hand, FIG. 5B shows a light source attachment portion 243 in the second illumination portion 230b and a light source attachment portion 243 in the third illumination portion 230c. When the illumination unit 230 emits light, the light source 231 generates heat. For this reason, the housing 110 includes a heat sink 120 in order to dissipate the heat generated by each light source 231. Hereinafter, in order to distinguish each light source 231, the light source of the 1st illumination part 230a is the 1st light source 231a, the light source of the 2nd illumination part 230b is the 2nd light source 231b, and the light source of the 3rd illumination part 230c is the 3rd light source 231c. Sometimes called.

  In general, the larger the heat sink 120 used for cooling the light source 231, the higher the heat dissipation effect. Therefore, if the first light source 231a, the second light source 231b, and the third light source 231c are radiated by one large heat sink, the effect is high in terms of heat radiation efficiency. On the other hand, when three different types of light sources that respectively generate red, green, and blue light are realized using LEDs, the light source that generates red light has a lower heat-resistant temperature than the other two-color light sources. Tend to be. For example, when the input power to each light source 231 is increased in order to increase the light amount of the light source 231, the amount of heat generated by each light source 231 increases. As a result, the temperature of the first light source 231a, which is a red light source, may reach its heat resistant temperature due to the heat generated by the second light source 231b and the third light source 231c, which are green and blue light sources.

  Therefore, the optical unit 100 according to the embodiment includes a dedicated heat sink 120 for cooling each light source 231.

  FIG. 6 is a diagram illustrating a case where the bottom surface of the housing 110 of the optical unit 100 according to the embodiment is observed from the outside. As shown in FIG. 6, on the outside of the housing 110, a heat sink 120a connected to the first light source 231a via the light source mounting part 243 of the first illumination unit 230a and a light source mounting part 243 of the second illumination unit 230b are provided. A heat sink 120b connected to the second light source 231b via the light source and a heat sink 120c connected to the third light source 231c via the light source mounting part 243 of the third illumination part 230c are provided. Hereinafter, in order to clearly distinguish the heat sink 120a, the heat sink 120b, and the heat sink 120c, they are referred to as a first heat sink 120a, a second heat sink 120b, and a third heat sink 120c, respectively.

  In order to protect the first light source 231a from the influence of heat generated by the second light source 231b and the third light source 231c, the thermal coupling property of the second heat sink 120b to the first heat sink 12a and the third heat sink 120c to the first heat sink 120a. The thermal bondability is configured to be lower than the thermal bondability between the second heat sink 120b and the third heat sink 120c.

  More specifically, the distance Lab from the first heat sink 120a to the second heat sink 120b and the distance Lac from the first heat sink 120a to the third heat sink 120c are both the distance from the second heat sink 120b to the third heat sink 120c. Longer than Lbc. The heat generated by the second light source 231b and transferred to the second heat sink 120b is transmitted to the third heat sink 120c closer to the distance than the first heat sink 120a. Similarly, the heat generated by the third light source 231c and transferred to the third heat sink 120c is also transferred to the second heat sink 120b closer to the distance than the first heat sink 120a. As a result, the thermal bondability between the second heat sink 120b and the third heat sink 120c depends on the thermal bondability of the second heat sink 120b with respect to the first heat sink 12a and the third heat sink 120c with respect to the first heat sink 120a. It becomes higher than thermal bondability.

  Further, the heat generated by each light source 231 and transferred to the heat sink 120 is transferred to the other heat sink 120 via the housing 110. Therefore, the second heat sink 120b for radiating the heat generated by the second light source 231b and the third heat sink 120c for radiating the heat generated by the third light source 231c are configured integrally with the housing 110. . On the other hand, the first heat sink 120a for radiating the heat generated by the first light source 231a is separated from the housing 110 and is externally attached. Thereby, the second heat sink 120b and the third heat sink 120c are physically separated from the first heat sink 120a. Therefore, the first heat sink 120a has low thermal connectivity with the second heat sink 120b and the third heat sink 120c.

  FIG. 7 is a diagram illustrating a case where the bottom surface of the housing 110 of the optical unit 100 according to the embodiment is observed from the outside with the first heat sink 120a removed. FIG. 8 is a diagram showing the first heat sink 120a in a state of being removed from the housing 110.

  As shown in FIG. 7, the housing 110 has an opening 112 at a position where the first heat sink 120 a is externally attached. As shown in FIG. 8, the first heat sink 120 a includes a connection portion 124 for connecting to the heat pipe 25 described above on the back surface, which is the surface opposite to the surface on which the cooling fins 122 are present. The connection part 124 is configured to protrude from the back surface of the first heat sink 120a. Here, the size of the cross section of the connection portion 124 is smaller than the opening portion 112 of the housing 110 and can be inserted into the opening portion 112. In addition, the height of the connection portion 124 is longer than the thickness of the housing 110, and the first heat sink 120 a is not in contact with the outer surface of the housing 110, and a part of the connection portion 124 is placed inside the housing 110. Can be protruded.

  FIG. 9 is a diagram illustrating a case where the first heat sink 120a is observed from the front side of the housing 110 in a state where the first heat sink 120a is attached to the housing 110 of the optical unit 100. Note that “observing the casing 110 from the front side” means observing the casing 110 from the upper side in the vertical direction with respect to the road surface when the optical unit 100 is installed in the vehicle.

  In order to avoid complication, the image projection unit 210 is not shown in FIG. 9, but the heat generated by the first light source 231a is transferred to the heat pipe 25 via the light source mounting portion 243 of the first illumination unit 230a. Is done. The heat pipe 25 is attached to the light source attachment portion 243 of the first light source 231a by the attachment member 26a. Similarly, the heat pipe 25 is attached to the connection portion 124 inserted into the housing 110 through the opening 112 using the attachment member 26b.

  As shown in FIG. 9, the first heat sink 120 a is externally attached to the housing 110 with the back surface of the first heat sink 120 a being separated from the housing 110. Accordingly, the first heat sink 120a is thermally separated from the housing 110. As a result, the first heat sink 120a is also thermally separated from the second heat sink 120b and the third heat sink 120c that are integrally formed with the housing 110.

  Although not shown, when the first heat sink 120a is attached to the housing 110, a material whose thermal bondability changes depending on the temperature between the connection portion 126 and the edge of the opening 112 of the housing 110. May be inserted. Examples of substances whose thermal connectivity changes according to temperature include, for example, bimetals and shape memory alloys. Hereinafter, in the present embodiment, as substances whose thermal connectivity changes according to temperature, A case where bimetal is used will be described.

  When the temperature of the edge of the opening 112 is low, the connection portion 126 of the first heat sink 120a is thermally coupled to the housing 110 via the bimetal. Thereby, since the 1st heat sink 120a, the 2nd heat sink 120b, and the 3rd heat sink 120c are thermally connected and integrated via the housing | casing 110, it becomes possible to improve heat dissipation efficiency.

  On the other hand, for example, it is assumed that the temperature of the housing 110 increases and the temperature of the bimetal also increases due to an increase in the amount of heat generated by each light source 231. In this case, the bimetal contracts due to deformation, so that the thermal connectivity between the connection portion 126 and the housing 110 is cut. Thereby, the heat generated by the second light source 231b and the third light source 231c is suppressed from being transferred to the first light source 231a via the housing 110, and the first light source 231a can be protected from heat.

  As described above, according to the head-up display 10 according to the embodiment of the present invention, a technique for improving the durability of the light emitting element can be provided.

  The present invention has been described based on the embodiments. The embodiments are exemplifications, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are within the scope of the present invention. .

  The optical unit 100 according to the above embodiment has been described with respect to the case where the first heat sink 120a includes the dedicated heat sink 120 in order to thermally separate the first heat sink 120a from the second heat sink 120b and the third heat sink 120c. On the other hand, as described above, generally, the heat sink 120 used for cooling the light source 231 has a higher heat dissipation effect as it is larger. Therefore, as a modified example, a configuration in which one heat sink 120a is thermally separated from the second heat sink 120b and the third heat sink 120c when each light source 231 is radiated by one large heat sink will be described.

(First modification)
FIG. 10 is a diagram showing the heat sink 120 and each light source 231 according to a first modification of the embodiment. The heat sink 120 according to the first modification is configured to cool the first light source 231a, the second light source 231b, and the third light source 231c independently.

  As shown in FIG. 10, the first light source 231a, the second light source 231b, and the third light source 231c are attached to the back surface of the heat sink 120, which is the surface opposite to the surface on which the cooling fins 122 are present. Here, in the heat sink 120, the portion where the second light source 231b and the third light source 231c are attached and the portion where the first light source 231a is attached are connected by a deformable member 128 whose shape changes with temperature. Yes. As described above, the deformable member 128 whose shape changes with temperature can be realized using, for example, a bimetal or a shape memory alloy.

  FIGS. 11A and 11B are diagrams illustrating enlarged connection locations of the deformable member 128 in the heat sink 120 according to the first modified example of the embodiment. FIG. 11A is a diagram illustrating a state of the deformable member 128 when the temperature of the deformable member 128 is lower than the heat resistant temperature of the first light source 231a, and FIG. It is a figure which shows the mode of the deformation | transformation member 128 when it approaches the heat-resistant temperature of 1 light source 231a.

  As shown in FIG. 11A, when the temperature of the deformable member 128 is lower than the heat resistant temperature of the first light source 231a, a portion of the heat sink 120 where the second light source 231b and the third light source 231c are attached; The part to which the first light source 231a is attached is connected to each other via the deformable member 128. For this reason, the heat sink 120 constitutes one large heat sink as a whole, and the heat radiation efficiency can be further improved.

  As shown in FIG. 11B, when the temperature of the deformable member 128 approaches the heat resistant temperature of the first light source 231a, the deformable member 128 is deformed. As a result, the portion of the heat sink 120 where the second light source 231b and the third light source 231c are attached is separated from the portion where the first light source 231a is attached, and the connected state is released. Thereby, the part in which the 2nd light source 231b and the 3rd light source 231c are attached, and the part in which the 1st light source 231a is attached also isolate | separate thermally. Therefore, heat generated by the second light source 231b and the third light source 231c can be suppressed from being transferred to the first light source 231a via the heat sink 120.

(Second modification)
FIG. 12 is a diagram showing a heat sink 120 and each light source 231 according to a second modification of the embodiment. Unlike the heat sink 120 according to the first modification, the heat sink 120 according to the second modification has a U-shape. On the other hand, the heat sink 120 according to the second modification example is provided with the portion to which the second light source 231b and the third light source 231c are attached and the first light source 231a, similarly to the heat sink 120 according to the first modification example. The deformed member 128 is connected to the connected portion. Therefore, the heat sink 120 according to the second modification also has the same effect as the heat sink 120 according to the first modification.

(Third Modification)
FIG. 13 is a diagram showing a heat sink 120 and each light source 231 according to a third modification of the embodiment. Unlike the heat sink 120 according to the first modification, the heat sink 120 according to the third modification is arranged so that each light source 231 forms a triangular apex, and the back surface thereof is a substantially square U-shape. The shape of the mold. In addition, the heat sink 120 according to the third modification is similar to the heat sink 120 according to the first modification in which the second light source 231b and the third light source 231c are attached and the first light source 231a is attached. Are connected by two deformation members 128a and 128b. Therefore, the heat sink 120 according to the third modification also has the same effect as the heat sink 120 according to the first modification.

  10 head-up display, 25 heat pipe, 50 control device, 100 optical unit, 110 housing, 112 opening, 120 heat sink, 122 cooling fin, 124, 126 connection, 128 deformation member, 210 image projection unit, 230 illumination unit , 231 light source, 232 collimating lens, 233 cut filter, 233 UV-IR cut filter, 234 polarizer, 235 fly eye lens, 236 reflector, 237 field lens, 238 polarization beam splitter, 239 phase difference plate, 240 image display element , 241 analyzer, 242 projection lens group, 243 light source mounting section, 244 dichroic cross prism, 350 intermediate mirror, 360 intermediate image forming section, 362 diffusion screen 364 concave lens, 400 projection mirror, 450 virtual image, 610 windshield.

Claims (5)

An image projection unit including a first light source, a second light source, and a third light source that emit light for generating image display light based on an image signal;
A housing that houses the image projection unit inside;
A first heat sink provided on the outside of the housing and connected to the first light source;
A second heat sink provided outside the housing and connected to the second light source;
A third heat sink provided on the outside of the housing and connected to the third light source,
The distance from the first heat sink to the second heat sink and the distance from the first heat sink to the third heat sink are both longer than the distance from the second heat sink to the third heat sink. Image display device.   The image display apparatus according to claim 1, wherein the first light source is an LED light source that emits red light.   Both the thermal bondability of the second heat sink to the first heat sink and the thermal bondability of the third heat sink to the first heat sink are the heat between the second heat sink and the third heat sink. The image display device according to claim 1, wherein the image display device is lower than a typical connectivity. The second heat sink and the third heat sink are configured integrally with the housing,
The image display device according to claim 1, wherein the first heat sink is externally attached to the housing.   5. The image display device according to claim 1, further comprising a heat pipe that connects the first light source and the first heat sink. 6.

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