Image irradiation device

Abstract

To provide an image irradiation device configured to project a display image generated by an image generation unit as a virtual image on an image display part, capable of generating a bright display image while suppressing a cost.SOLUTION: In a configuration in which a mask member 26 covering an outer peripheral edge region of a liquid crystal panel 22 is supported by a panel support member 24, a heat insulating material 44 is disposed between the mask member 26 and a heat sink 40 on which a light emitting element 32 of an optical unit 30 is mounted. Thus, even when a temperature of the mask member 26 rises due to a backlight irradiation or a sunlight irradiation from the optical unit 30, the heat is not directly transmitted to the heat sink 40, and a heat dissipation function of the heat sink 40 is not hindered by the presence of the mask member 26. In addition, this can be realized by additionally arranging the heat insulating material 44 after diverting the mask member 26 instead of using a dedicated heat transfer panel.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image projection device configured to project a display image generated by an image generation unit onto an image display section as a virtual image. [Background technology]

[0002] Conventionally, there has been known an in-vehicle image projection device that is configured to project a virtual image onto an image display unit such as a front window (i.e., windshield) or a light-transmitting plate arranged inside the vehicle cabin when placed inside the vehicle cabin.

[0003] Patent Document 1 describes such an image projection device in which the image generation unit for generating the display image that serves as the basis for the virtual image is configured to include a liquid crystal panel and an optical unit that irradiates the liquid crystal panel with backlight.

[0004] The image projection device described in Patent Document 1 has a configuration in which a heat transfer panel is disposed between a liquid crystal panel and a heat sink on which a light emitting element of an optical unit is mounted. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-3732 Summary of the Invention [Problem to be solved by the invention]

[0006] In order to project a bright virtual image onto the image display unit in such an image projection device, it is necessary to use a high-output optical unit as the image generation unit, but this configuration makes the liquid crystal panel prone to overheating.

[0007] In contrast to this, as described in the above-mentioned "Patent Document 1," if a heat transfer panel is placed between the liquid crystal panel and the heat sink, the heat generated by the liquid crystal panel can be dissipated to the heat sink via the heat transfer panel, thereby making it possible to prevent the liquid crystal panel from overheating.

[0008] However, when such a configuration is adopted, a new heat transfer panel is required, which increases the cost of the image projection device.

[0009] Furthermore, when such a configuration is adopted, there is a risk that the inherent heat dissipation function of the heat sink, which is to dissipate heat generated by the light emitting elements of the optical unit, may not be fully exerted.

[0010] It should be noted that such a problem can also occur in image projection devices other than those mounted on vehicles.

[0011] The present invention has been made in consideration of the above circumstances, and aims to provide an image projection device that is configured to project a display image generated by an image generation unit as a virtual image on an image display unit, and that is capable of generating a bright display image while keeping costs down. [Means for solving the problem]

[0012] The present invention aims to achieve the above object by devising an image generating unit configuration.

[0013] That is, the image projection device according to the present invention is An image projection device configured to project a display image generated by an image generation unit onto an image display unit as a virtual image, the image generating unit includes a liquid crystal panel, an optical unit that irradiates the liquid crystal panel with a backlight, a panel support member that supports the liquid crystal panel, and a mask member that is supported by the panel support member and that is disposed so as to cover an outer peripheral edge region of the liquid crystal panel; the optical unit includes a light emitting element mounted on a heat sink; the heat sink is fixed to the panel support member, The mask member is made of a material having a higher thermal conductivity than the liquid crystal panel, and is in contact with the heat sink via a heat insulating material.

[0014] The above-mentioned "image projection device" is not particularly limited in its specific use as long as it is configured to project a virtual image on an image display unit, and can be used, for example, as an in-vehicle head-up display.

[0015] The specific configuration of the above-mentioned "image display unit" is not particularly limited as long as it is configured to project a virtual image, and for example, a translucent plate placed on the front window of a vehicle or the inside of the passenger compartment can be used.

[0016] The "light emitting element" may be mounted directly on the heat sink or may be mounted via a substrate or the like.

[0017] The above-mentioned "mask member" is arranged so as to cover the outer peripheral edge region of the liquid crystal panel, and thus has a configuration having an opening, but the specific shape of the opening is not particularly limited.

[0018] The above-mentioned "mask member" is made of a material with a higher thermal conductivity than the liquid crystal panel, and as long as it is in contact with the heat sink via a heat insulating material, its specific material and shape are not particularly limited. [Effects of the Invention]

[0019] The image projection device of the present invention comprises an image generation unit for generating a display image that is the basis for the virtual image projected on the image display unit, which comprises a liquid crystal panel, an optical unit that irradiates the liquid crystal panel with backlight, a panel support member that supports the liquid crystal panel, and a mask member that is supported by the panel support member and is positioned so as to cover the outer peripheral area of ​​the liquid crystal panel, and therefore can achieve the following effects.

[0020] That is, by configuring the image projection device with a mask member, it is possible to define the use area of ​​the liquid crystal panel. Also, even if sunlight enters the internal space of the image projection device, the light-blocking function of the mask member can suppress the temperature rise of the liquid crystal panel to a certain extent.

[0021] In this case, the mask member abuts against the heat sink on which the light-emitting elements of the optical unit are mounted via a heat insulating material, so even if the temperature of the mask member rises due to backlight irradiation from the optical unit or sunlight irradiation, the heat is not directly transferred to the heat sink. Therefore, the mask member does not impede the heat dissipation function of the heat sink, which is to dissipate heat generated by the light-emitting elements of the optical unit, and this makes it possible to increase the output of the optical unit while suppressing overheating of the liquid crystal panel.

[0022] Furthermore, by configuring the mask member so that an insulating material is placed between the mask member and the heat sink in this manner, the mask member can be formed to extend to a position close to the heat sink, thereby ensuring sufficient surface area for the mask member and thereby improving its heat dissipation function.

[0023] Moreover, this can be achieved by reusing the masking material used to define the usable area of ​​the liquid crystal panel and then adding heat insulating material, rather than using a dedicated heat transfer panel, thereby reducing the cost of the image projection device and generating a bright display image.

[0024] Thus, according to the present invention, in an image projection device configured to project a display image generated by an image generation unit as a virtual image on an image display unit, it is possible to generate a bright display image while keeping costs down.

[0025] In the above configuration, if the mask member is further configured so that heat dissipation fins are formed on the outer peripheral surface of the end portion on the insulating material side, even if the liquid crystal panel becomes hot, the heat can be efficiently dissipated from the heat dissipation fins of the mask member, thereby effectively preventing the liquid crystal panel from overheating.

[0026] In this case, if heat dissipation fins are formed at a plurality of locations on the outer peripheral surface, the heat dissipation function of the mask member can be further improved.

[0027] In the above configuration, if the mask member is further configured to include an inclined flange portion formed so as to extend in an inclined direction toward the outer periphery of the liquid crystal panel from the position of the inner peripheral edge portion in the outer peripheral edge region of the liquid crystal panel toward the front in the direction of backlight irradiation, the surface area of ​​the mask member can be increased while preventing the light emitted from the liquid crystal panel from being blocked, thereby further improving the heat dissipation function of the mask member.

[0028] In this case, if the mask member is configured to have an opening with a rectangular opening shape and an inclined flange portion extending from a pair of long sides thereof, the mask member can be maintained in a shape that can be easily manufactured while ensuring its heat dissipation function. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 is a side cross-sectional view showing an image projection device according to an embodiment of the present invention mounted on a vehicle. [Figure 2] View in the direction of arrow II in Figure 1 [Figure 3] Detailed view of part III in Figure 1 [Figure 4] Cross section of line IV-IV in Figure 3 [Figure 5] FIG. 2 is a perspective view showing an image generating unit of the image projection device together with its peripheral structure. [Figure 6] FIG. 2 is an exploded perspective view showing the image generating unit together with its peripheral structure. [Figure 7] FIG. 6 is a view similar to FIG. 5, showing a first modified example of the embodiment; [Figure 8] FIG. 4 is a view similar to FIG. 3, showing a second modification of the embodiment; [Figure 9] FIG. 6 is a diagram similar to FIG. 5, illustrating the second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0031] Fig. 1 is a side cross-sectional view showing an image projection device 10 according to an embodiment of the present invention in a state where it is mounted on a vehicle 100. Fig. 2 is a view taken in the direction of the arrow II in Fig. 1.

[0032] 1 and 2, the direction indicated by X is the "forward" direction of the image projection device 10 (also "forward" as a vehicle), the direction indicated by Y is the "leftward" direction perpendicular to the "forward" direction, and the direction indicated by Z is the "upward" direction. This is the same in other figures than FIGS. 1 and 2.

[0033] As shown in Figures 1 and 2, the image projection device 10 of this embodiment is an in-vehicle head-up display, and is configured to project a virtual image PIC onto an image display unit 102A set on the inner surface of the front windshield 102 when placed inside the passenger compartment of a vehicle 100.

[0034] An optical path R shown in FIG. 1 is an optical path taken by the driver 2 when the driver 2 visually recognizes the virtual image PIC projected on the image display unit 102A by the image projection device 10. As shown in FIG.

[0035] The image display unit 102A is positioned in the lower region of the windshield 102 and in the region in front of the steering wheel 104, and is set as a horizontally elongated rectangular region, so that the driver 2 of the vehicle 100 can easily visually recognize the virtual image PIC projected on the image display unit 102A.

[0036] In addition, FIG. 2 shows a specific example of the virtual image PIC in which the vehicle speed (50 Km / h) is displayed together with a left-pointing arrow.

[0037] The image projection device 10 is disposed in front of the steering wheel 104 and in the vicinity of the lower part of the windshield 102 .

[0038] As shown in FIG. 1, the image projection device 10 is configured to include an image generation unit 20 that generates a display image that serves as the basis for the virtual image PIC, first and second reflectors 70, 80 that sequentially reflect the light emitted from the image generation unit 20 toward the image display section 102A of the front window 102, a housing 50 that accommodates these, and a translucent cover 60 attached to the housing 50.

[0039] The housing 50 is configured such that a second housing 54 is assembled to a first housing 52 formed to open upward.

[0040] The second housing 54 has an outer peripheral flange portion 54b, and is assembled to the first housing 52 with this outer peripheral flange portion 54b in contact with the upper end opening of the peripheral wall portion 52a of the first housing 52.

[0041] The first and second housings 52 and 54 are both made of opaque resin moldings. The second housing 54 has an opening 54a formed therein to allow reflected light from the second reflecting mirror 80 to pass through toward the image display unit 102A.

[0042] The light-transmitting cover 60 is made of a colorless, transparent resin panel. The light-transmitting cover 60 is arranged so as to cover the opening 54a of the second housing 54, in a state where it is curved downward and tilted slightly upward toward the rear. The light-transmitting cover 60 allows the reflected light from the second reflecting mirror 80 to be incident on the image display unit 102A, while ensuring that the internal space 12 of the housing 50 is dust-proof.

[0043] The second housing 54 is formed with a light-shielding piece 54c that extends diagonally downward and forward from the rear edge of the opening 54a toward the internal space 12. The light-shielding piece 54c prevents sunlight S that has entered the internal space 12 through the front window 102 and the translucent cover 60 from reaching the image generation unit 20 as direct light.

[0044] The image generating unit 20 and the first reflecting mirror 70 are arranged in a rear region of the interior space 12 , and the second reflecting mirror 80 is arranged in a front region of the interior space 12 .

[0045] The first and second reflecting mirrors 70, 80 have reflective surfaces 70a, 80a that are symmetrical, and the image generating unit 20 is disposed at the center in the left-right direction. The image generating unit 20 is supported by the lower wall portion 52b of the first housing 52 (this will be described later).

[0046] The first reflecting mirror 70 is disposed substantially directly above the image generating unit 20 and is configured to reflect the light emitted from the image generating unit 20 forward. The reflecting surface 70a of the first reflecting mirror 70 has an outer shape that is horizontally elongated and rectangular when viewed from the front of the device. The horizontal cross section of the reflecting surface 70a is configured as a convex curve, and the vertical cross section is configured as a concave curve.

[0047] The second reflecting mirror 80 is disposed in front of the first reflecting mirror 70. The second reflecting mirror 80 is configured to reflect the irradiated light from the image generating unit 20, which is reflected by the first reflecting mirror 70, upward.

[0048] The second reflecting mirror 80 is a concave mirror, and its reflecting surface 80a is configured as a substantially spherical concave curved surface. The reflecting surface 80a of the second reflecting mirror 80 has an outer shape of a horizontally elongated rectangle when viewed from the front of the device, and is formed to be larger in size than the reflecting surface 70a of the first reflecting mirror 70.

[0049] The second reflecting mirror 80 is supported rotatably about an axis Ax extending in the left-right direction relative to the first housing 52. Specifically, the second reflecting mirror 80 has a pair of left and right flange portions 80b formed to protrude from both left and right ends thereof toward the rear side of the reflecting surface 80a, and one of the flange portions 80b is connected to an actuator 82 fixed to the first housing 52. The second reflecting mirror 80 rotates about the axis Ax when driven by the actuator 82, thereby enabling adjustment of the vertical position of the virtual image PIC formed on the image display unit 102A by the light reflected from the second reflecting mirror 80.

[0050] Next, the image generating unit 20 and its peripheral structure will be described.

[0051] 3 is a detailed view of part III in FIG. 1, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

[0052] As shown in Figures 3 and 4, the image generating unit 20 includes a liquid crystal panel 22, an optical unit 30 that illuminates the liquid crystal panel 22 with backlight from its rear side (i.e., the lower side), a panel support member 24 that supports the liquid crystal panel 22, and a mask member 26 that covers the outer peripheral edge region of the liquid crystal panel 22.

[0053] A diffuser plate 28 is disposed between the optical unit 30 and the liquid crystal panel 22 so as to extend along the lower surface of the liquid crystal panel 22, for making the light emitted from the optical unit 30 incident on the liquid crystal panel 22 as diffused light.

[0054] The liquid crystal panel 22 has a horizontally elongated rectangular shape and is arranged along a horizontal plane. The liquid crystal panel 22 is supported at its outer periphery by a panel support member 24 via a diffusion plate 28.

[0055] The optical unit 30 includes a plurality of light-emitting elements 32, a substrate 34 on which the plurality of light-emitting elements 32 are mounted, and a lens member 36 that controls the deflection of light emitted from the plurality of light-emitting elements 32.

[0056] The plurality of light-emitting elements 32 are all white light-emitting diodes and are arranged in a grid pattern. Specifically, the plurality of light-emitting elements 32 are arranged in two locations at regular intervals in the front-rear direction and in five locations at equal intervals in the left-right direction, for a total of 10 locations.

[0057] The substrate 34 is disposed along a horizontal plane so that the light emitting surfaces of the plurality of light emitting elements 32 face upward. The substrate 34 is supported on a heat sink 40 at its lower surface.

[0058] The heat sink 40 is made of a metal material such as aluminum, and includes a main body 40A extending flat along a horizontal plane, and a plurality of heat dissipation fins 40B extending downward from the main body 40A at intervals in the left-right direction.

[0059] The lens member 36 has a configuration in which a plurality of convex lens portions 36a are formed on the upper surface of a horizontally elongated rectangular plate-like portion arranged along a horizontal plane. These convex lens portions 36a are formed in ten locations so as to be positioned directly above the plurality of light-emitting elements 32, thereby deflecting the light emitted from each of the plurality of light-emitting elements 32 in a direction closer to directly above. The lens member 36 is supported by the panel support member 24 at the outer peripheral edge of its plate-like portion.

[0060] The image generating unit 20 is configured to generate a display image (i.e., an image that serves as the basis for the virtual image PIC) with uniform brightness on the liquid crystal panel 22 by deflecting and controlling the light emitted from the multiple light-emitting elements 32 using a lens member 36 and then making the light incident on the liquid crystal panel 22 via a diffuser plate 28.

[0061] The lower wall portion 52b of the first housing 52 is formed with a recess 52b1 having an inner surface shape that is approximately the same as the outer shape of the main body portion 40A of the heat sink 40, and this recess 52b1 is formed with a rectangular opening 52b2 for inserting multiple heat dissipation fins 40B.

[0062] The heat sink 40 is accommodated in a recess 52b1 in the lower wall portion 52b of the first housing 52, with its multiple heat dissipation fins 40B inserted into the openings 52b2, and in this state, its main body portion 40A is placed on the recess 52b1 around the openings 52b2.

[0063] The panel support member 24 is made of an opaque resin molded product and has a horizontally elongated rectangular shape in a plan view. The panel support member 24 is positioned and fixed to the first housing 52 by fastening it together with the heat sink 40.

[0064] That is, a pair of front and rear tabs 24a extending laterally are formed on both the left and right sides of the panel support member 24. Then, with the panel support member 24 placed on the main body 40A of the heat sink 40, the two pairs of left and right tabs 24a are fastened with screws 42 via the main body 40A, thereby fixing the panel support member 24 to the bottom wall 52b of the first housing 52.

[0065] FIG. 5 is a perspective view showing the image generating unit 20, and FIG. 6 is an exploded perspective view thereof.

[0066] 6, rectangular recessed openings 24d are formed in multiple locations on the peripheral wall of the panel support member 24. Specifically, the recessed openings 24d are formed in a total of six locations: two on the left and right of the pair of front and rear peripheral walls of the panel support member 24 and one on the pair of left and right peripheral walls.

[0067] The mask member 26 is made of a material (specifically, a metal material such as aluminum) having a higher thermal conductivity than the liquid crystal panel 22. The mask member 26 includes a mask main body 26A extending like a flat plate along a horizontal plane, a pair of front and rear flanges 26B extending directly downward from both front and rear edge portions of the mask main body 26A, and a pair of left and right flanges 26C extending directly downward from both left and right edge portions of the mask main body 26A.

[0068] The pair of front and rear flanges 26B are formed across the entire width of the mask body 26A, and the pair of left and right flanges 26C are formed at intermediate positions between the pair of front and rear tabs 24a.

[0069] The mask main body 26A has an opening 26Aa formed in a horizontally elongated rectangular shape that is slightly smaller than the liquid crystal panel 22. That is, the mask member 26 is configured to cover the outer peripheral edge region of the liquid crystal panel 22.

[0070] As shown in Figure 5, when the mask member 26 is fixed to the panel support member 24, it is configured so that its pair of front and rear flange portions 26B and its pair of left and right flange portions 26C cover the opening recesses 24d formed in six locations on the peripheral wall portion of the panel support member 24.

[0071] The mask member 26 is fixed to the panel support member 24 by caulking (specifically, by thermal caulking) at three locations: the central position in the left-right direction on the front side of the opening 26Aa, and both left and right end positions on the rear side of the opening 26Aa.

[0072] 6, crimping pins 24b are formed at the three locations on the upper surface of the panel support member 24, and pin insertion holes 26Ab for inserting the crimping pins 24b are formed at the three locations on the mask main body 26A. Of the three pin insertion holes 26Ab, the pin insertion hole 26Ab located on the front side of the opening 26Aa is configured as a round hole, and the remaining two are configured as elongated holes extending in the left-right direction.

[0073] Furthermore, a pair of left and right positioning pins 24c are formed on the upper surface of the panel support member 24 at positions forward of the pair of left and right crimping pins 24b, and a pair of left and right pin insertion holes 26Ac are formed in the mask main body 26A for inserting the pair of left and right positioning pins 24c. In this case, each of the pair of left and right pin insertion holes 26Ac is formed as an elongated hole extending in the front-rear direction.

[0074] Then, the three crimping pins 24b are inserted into the three pin insertion holes 26Ab, and a pair of left and right positioning pins 24c are inserted into a pair of left and right pin insertion holes 26Ac. Then, the tips of the three crimping pins 24b are heated and crushed, thereby thermally crimping the mask member 26 to the panel support member 24, as shown in Figure 5.

[0075] By performing this thermal caulking, the mask member 26 is positioned horizontally relative to the panel support member 24. The mask member 26 is formed so that, when the panel support member 24 is fixed to the heat sink 4, the lower end surfaces of the pair of front and rear flange portions 26B and the pair of left and right flange portions 26C are located above and in the vicinity of the upper surface of the main body portion 40A of the heat sink 40. The mask member 26 is configured so that the lower end surfaces of the pair of front and rear flange portions 26B and the pair of left and right flange portions 26C abut against the upper surface of the main body portion 40A of the heat sink 40 via the heat insulating material 44.

[0076] The heat insulating material 44 is made of a flat heat insulating sheet (e.g., a rubber sheet) having an outer shape slightly smaller than the outer shape of the main body 40A of the heat sink 40. The heat insulating material 44 has an opening 44a formed therein, the opening shape of which is substantially the same as the outer shape of the panel support member 24. The heat insulating material 44 is placed on the upper surface of the main body 40A of the heat sink 40, with the panel support member 24 fitted into the opening 44a.

[0077] The heat insulating material 44 is formed with a thickness slightly greater than the distance between the lower end surfaces of the pair of front and rear flange portions 26B and the pair of left and right flange portions 26C of the mask member 26 and the upper surface of the main body portion 40A of the heat sink 40, so that the lower end surfaces of the pair of front and rear flange portions 26B and the pair of left and right flange portions 26C reliably abut against the upper surface of the main body portion 40A of the heat sink 40 via the heat insulating material 44. As a result, when the mask member 26 is fixed to the panel support member 24, the pair of front and rear flange portions 26B and the pair of left and right flange portions 26C reliably cover the six opening recesses 24d.

[0078] Next, the operation of this embodiment will be described.

[0079] The image projection device 10 of this embodiment includes an image generation unit 20 for generating a virtual image PIC to be displayed on the image display unit 102A, which includes a liquid crystal panel 22, an optical unit 30 for irradiating the liquid crystal panel 22 with backlight, a panel support member 24 for supporting the liquid crystal panel 22, and a mask member 26 supported by the panel support member 24 in a state where it is positioned to cover the outer peripheral region of the liquid crystal panel 22, and therefore the following effects can be obtained.

[0080] That is, by configuring the image projection device 10 so that the mask member 26 is arranged, it is possible to define the use area of ​​the liquid crystal panel 22. Furthermore, even if sunlight S is incident on the internal space 12 of the image projection device 10, the light-blocking function of the mask member 26 can suppress the temperature rise of the liquid crystal panel 22 to a certain extent.

[0081] In this case, the mask member 26 abuts against the heat sink 40 on which the light emitting elements 32 of the optical unit 30 are mounted via the heat insulating material 44, so that even if the temperature of the mask member 26 rises due to backlight irradiation from the optical unit 30 or sunlight irradiation, the heat is not directly transferred to the heat sink 40. Therefore, the presence of the mask member 26 does not impede the heat dissipation function of the heat sink 40, which is to dissipate heat generated by the light emitting elements 32 of the optical unit 30, and this makes it possible to suppress overheating of the liquid crystal panel 22 while achieving high output of the optical unit 30.

[0082] Furthermore, by configuring the mask member 26 in this manner, with the insulating material 44 disposed between the mask member 26 and the heat sink 40, the mask member 26 can be formed to extend to a position close to the heat sink 40, thereby ensuring a sufficient surface area for the mask member 26.

[0083] Specifically, the mask member 26 of this embodiment is configured so that the lower end surfaces of a pair of front and rear flange portions 26B and a pair of left and right flange portions 26C, which are formed to extend directly downward from the mask main body portion 26A, abut the upper surface of the main body portion 40A of the heat sink 40 via the insulating material 44, thereby ensuring sufficient surface area of ​​the mask member 26 and thereby improving the heat dissipation function of the mask member 26.

[0084] Moreover, this can be achieved by reusing the mask member 26 that defines the use area of ​​the liquid crystal panel 22, rather than using a dedicated heat transfer panel, and then additionally arranging the heat insulating material 44. This makes it possible to generate a bright image for display while suppressing the cost of the image projection device 10.

[0085] Thus, according to this embodiment, in the image projection device 10 configured to project the display image generated by the image generation unit 20 as a virtual image PIC on the image display section 102A, it is possible to generate a bright display image while keeping costs down.

[0086] Furthermore, the image projection device 10 of this embodiment is configured so that the opening recesses 24d formed at six locations on the panel support member 24 are covered by a pair of front and rear flange portions 26B and a pair of left and right flange portions 26C on the mask member 26, thereby preventing the occurrence of a situation in which light emitted from the multiple light-emitting elements 32 in directions other than the liquid crystal panel 22 becomes stray light.

[0087] Furthermore, the mask member 26 of this embodiment is made of a metal member including a flat mask main body 26A, a pair of front and rear flanges 26B, and a pair of left and right flanges 26C, and can be easily manufactured by bending and drilling a metal plate using press forming or the like. Instead of adopting such a configuration, the mask member 26 can also be made as an aluminum die-cast product or the like.

[0088] In the above embodiment, the optical unit 30 has been described as including ten light-emitting elements 32 and a lens member 36 having ten convex lens portions 36a, but it is also possible to configure the optical unit 30 to include any other number of light-emitting elements 32 and convex lens portions 36a.

[0089] In the above embodiment, the configuration is described as including first and second reflecting mirrors 70 and 80, but it is also possible to have a configuration that includes only second reflecting mirror 80, and it is also possible to have a configuration in which light emitted from image generating unit 20 is directly incident on image display section 102A.

[0090] In the above embodiment, the image display unit 102A is described as being set on the inner surface of the front windshield 102, but it is also possible to configure the image display unit using a translucent plate or the like arranged on the inside of the vehicle cabin of the front windshield 102.

[0091] In the above embodiment, the image projection device 10 has been described as being an in-vehicle head-up display, but it may also be used for other purposes.

[0092] Next, a modification of the above embodiment will be described.

[0093] First, a first modification of the above embodiment will be described.

[0094] FIG. 7 is a diagram similar to FIG. 5, showing an image generating unit 120 of an image projection device according to this modified example.

[0095] As shown in FIG. 7, the basic configuration of the image generating unit 120 of this modified example is the same as that of the image generating unit 20 of the above embodiment, but the configuration of the mask member 126 is different from that of the above embodiment.

[0096] That is, like the mask member 26 of the above embodiment, the mask member 126 of this modified example also has a pair of front and rear flange portions 126B extending directly downward from both front and rear edge portions of the mask main body portion 126A, and a pair of left and right flange portions 126C extending directly downward from both left and right edge portions of the mask main body portion 126A, and an opening 126Aa is formed in the mask main body portion 126A.

[0097] In addition, the mask member 126 of this modified example is configured such that heat dissipation fins 126Ba, 126Ca are formed at multiple locations on the outer peripheral surface of the lower end of the pair of front and rear flange portions 126B and the pair of left and right flange portions 126C.

[0098] Specifically, 22 heat dissipation fins 126Ba are formed at equal intervals in the left-right direction on the pair of front and rear flange portions 126B, and 6 heat dissipation fins 126Ca are formed at equal intervals in the front-to-back direction on the pair of left and right flange portions 126C.

[0099] In this case, the plurality of heat dissipation fins 126Ba are formed in a state in which the lower ends of a pair of front and rear flange portions 126B are bent horizontally, and the plurality of heat dissipation fins 126Ca are formed in a state in which the lower ends of a pair of left and right flange portions 126C are bent horizontally.

[0100] In this modified example, a heat insulating material 44 is also disposed between the mask member 126 and the heat sink 40. In this case, the mask member 126 is configured to abut against the heat insulating material 44 at the lower surfaces of the plurality of heat dissipation fins 126Ba formed on the pair of front and rear flange portions 126B and the lower surfaces of the plurality of heat dissipation fins 126Ca formed on the pair of left and right flange portions 126C.

[0101] Even when the configuration of this modified example is adopted, the same effects as those of the above embodiment can be obtained.

[0102] Furthermore, by configuring the mask member 126 of this modified example so that heat dissipation fins 126Ba, 126Ca are formed on the outer peripheral surface of the end portion on the insulating material 44 side, even if the temperature of the liquid crystal panel 22 rises, the heat can be efficiently dissipated from the heat dissipation fins 126Ba, 126Ca of the mask member 126, thereby effectively preventing the liquid crystal panel 22 from overheating.

[0103] Moreover, since the heat dissipation fins 126Ba, 126Ca are formed at multiple locations on the outer peripheral surfaces of the pair of front and rear flange portions 126B and the pair of left and right flange portions 126C, the heat dissipation function of the mask member 126 can be further improved.

[0104] Next, a second modification of the above embodiment will be described.

[0105] 8 and 9 are diagrams similar to FIGS. 3 and 5, showing an image generating unit 220 of an image projection device according to this modified example.

[0106] As shown in FIGS. 8 and 9, the basic configuration of the image generating unit 220 of this modified example is the same as that of the image generating unit 20 of the above embodiment, but the configuration of the mask member 226 is different from that of the above embodiment.

[0107] That is, like the mask member 26 of the above embodiment, the mask member 226 of this modified example also has a pair of front and rear flange portions 226B extending directly downward from both front and rear edge portions of the mask main body portion 226A, and a pair of left and right flange portions 226C extending directly downward from both left and right edge portions of the mask main body portion 226A, and the mask main body portion 226A is configured to have an opening 226Aa formed therein that has a horizontally elongated rectangular (i.e., rectangular) opening shape.

[0108] Furthermore, the mask main body portion 226A of the mask member 226 is configured to have a pair of front and rear inclined flange portions 226D formed to extend upward (i.e., forward in the direction of backlight irradiation) from the positions of a pair of front and rear inner peripheral edge portions in the outer peripheral edge region of the liquid crystal panel 26 (i.e., the long side portions of the opening 226Aa) in a direction inclined on both the front and rear sides (i.e., a direction inclined toward the outer periphery of the liquid crystal panel 26).

[0109] The pair of front and rear inclined flanges 226D are formed by bending a metal plate and cutting out and raising a part of the mask main body 226A. In this case, the inclination angle of the pair of front and rear inclined flanges 226D is set to a value that does not block the backlight emitted from the optical unit 30 and directed toward the liquid crystal panel 22 through the opening 226Aa, as shown in Fig. 8.

[0110] Even when the configuration of this modified example is adopted, the same effects as those of the above embodiment can be obtained.

[0111] Furthermore, as in the mask member 226 of this modified example, by configuring the mask main body 226A to have a pair of front and rear inclined flange portions 226D extending upward in an inclined direction on both the front and rear sides from the positions of a pair of front and rear inner peripheral edge portions in the outer peripheral edge region of the liquid crystal panel 26, the surface area of ​​the mask member 226 can be increased, thereby preventing the light emitted from the liquid crystal panel 22 from being blocked and further improving the heat dissipation function of the mask member 226.

[0112] Furthermore, the pair of front and rear inclined flange portions 226D are formed to extend from the pair of front and rear long side portions of the opening 226Aa, which has a horizontally elongated rectangular opening shape, so that the mask member 226 can be maintained in a shape that can be easily manufactured while ensuring its heat dissipation function.

[0113] By adopting the mask member 226 of this modified example, it is also possible to configure the mask member 226 such that heat dissipation fins similar to the heat dissipation fins 126Ba, 126Ca of the first modified example are additionally formed at multiple locations on the outer peripheral surfaces of the pair of front and rear flange portions 226B and the pair of left and right flange portions 226C.

[0114] It should be noted that the numerical values ​​shown as the specifications in the above embodiment and its modified examples are merely examples, and it goes without saying that these may be set to different values ​​as appropriate.

[0115] Furthermore, the present invention is not limited to the configurations described in the above embodiment and its modified examples, and various other modified configurations can be adopted. [Explanation of symbols]

[0116] 2 Driver 10. Image irradiation device 12 Interior Space 20, 120, 220 image generation units 22 LCD panel 24 Panel support member 24a Tab 24b Crimp pin 24c Locating Pin 24d Opening recess 26, 126, 226 Mask material 26A, 126A, 226A Mask body 26Aa, 126Aa, 226Aa opening 26Ab, 26Ac pin insertion holes 26B, 26C, 126B, 126C, 226B, 226C flange 28 Diffuser 30 Optical Unit 32 Light-emitting element 34 PCB 36 Lens components 36a Convex lens part 40 Heatsink 40A main body 40B Heat dissipation fin 42 screws 44 Insulation 44a opening 50 Housing 52 First Housing 52a Peripheral wall part 52b Lower wall part 52b1 Recess 52b2 opening 54 Second Housing 54a opening 54b Outer flange 54c Light shielding piece 60 Translucent cover 70 1st reflector 70a, 80a reflective surface 80 Second reflector 80b flange 82 Actuator 100 vehicles 102 Front window 102A Image display section 104 Steering Wheel 126Ba, 126Ca heat dissipation fin 226D Inclined flange Ax axis PIC virtual image R optical path S Sunlight

Claims

1. An image projection device configured to project a display image generated by an image generation unit onto an image display unit as a virtual image, the image generating unit includes a liquid crystal panel, an optical unit that irradiates the liquid crystal panel with a backlight, a panel support member that supports the liquid crystal panel, and a mask member that is supported by the panel support member and that is disposed so as to cover an outer peripheral edge region of the liquid crystal panel; the optical unit includes a light emitting element mounted on a heat sink; the heat sink is fixed to the panel support member, The image projection device is characterized in that the mask member is made of a material having a higher thermal conductivity than the liquid crystal panel, and is in contact with the heat sink via a heat insulating material.

2. 2. The image projection device according to claim 1, wherein a heat dissipation fin is formed on the outer peripheral surface of the end of said mask member on the side of said heat insulating material.

3. 3. The image projection device according to claim 2, wherein the heat dissipation fins are formed at a plurality of locations on the outer peripheral surface.

4. 3. The image projection device according to claim 1, wherein the mask member has an inclined flange portion formed so as to extend in a direction inclined toward the outer periphery of the liquid crystal panel from the position of the inner periphery of the outer periphery region of the liquid crystal panel toward the front in the irradiation direction of the backlight.

5. The mask member has an opening formed therein, the opening having a rectangular opening shape.

5. The image projection device according to claim 4, wherein the inclined flange portions are formed so as to extend from a pair of long side portions of the opening.

Images