Image irradiation apparatus

Abstract

To provide an image irradiation apparatus configured to show a display image on an image display unit with light emitted from an image generation unit, while allowing a liquid crystal panel of the image generation unit to be arranged with high positional accuracy with respect to an optical unit, with low-cost configuration.SOLUTION: A panel support member 70 for supporting a liquid crystal panel 22 is configured so that a pair of left and right engagement sections 72 that are engaged with both edges of the liquid crystal panel 22 are formed in portions located at both ends of an opening 70a. The liquid crystal panel 22 is supported by the panel support member 70 when the liquid crystal panel 22 is slid with respect to the panel support member 70 to be engaged with the pair of left and right engagement sections 72. Accordingly, configuration of the panel support member 70 can be simplified and an image irradiation apparatus can be configured at low cost.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an image projection device configured to project a display image on an image display section. [Background technology]

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

[0003] Patent Document 1 describes such an image projection device as comprising an image generating unit that generates an image for display, and a reflecting mirror that reflects the light emitted from the image generating unit toward an image display section.

[0004] The image generating unit of the image projection device described in "Patent Document 1" includes a liquid crystal panel and an optical unit that performs backlight irradiation on the liquid crystal panel. [Patent Document 1] International Publication No. 2020 / 110580 Summary of the Invention [Problem to be solved by the invention]

[0005] In such an image projection device, in order to accurately project a display image onto the image display section, it is important to position the liquid crystal panel with high positional accuracy relative to the optical unit.

[0006] To achieve this, the image projection device may be configured to include a panel support member that supports the liquid crystal panel, and the panel support member may be configured to include a pair of support members that are arranged to clamp the liquid crystal panel from both the front and back sides and are fixed with screws at multiple locations.

[0007] However, when such a configuration is adopted, the number of components constituting the panel support member increases, making it difficult to construct the image projection device at low cost.

[0008] Such a problem can also occur in image projection devices other than those mounted on vehicles.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide an image projection device configured to project a display image on an image display section using light emitted from an image generation unit, which has an inexpensive configuration and can position the liquid crystal panel of the image generation unit with high positional accuracy relative to its optical unit. [Means for solving the problem]

[0010] The present invention is intended to achieve the above object by providing an improved configuration for the panel support member.

[0011] That is, the image projection device according to the present invention is In an image projection device configured to project a display image on an image display unit, an image generating unit that generates the display image; and a reflecting mirror that reflects light emitted from the image generating unit toward the image display unit, the image generating unit includes a liquid crystal panel, an optical unit that irradiates the liquid crystal panel with a backlight, and a panel support member that supports the liquid crystal panel; an opening is formed in the panel support member to allow backlight irradiation light from the optical unit to pass through toward the reflecting mirror; a pair of engagement portions that engage with both side edges of the liquid crystal panel are formed in the panel support member at portions located on both sides of the opening, The liquid crystal panel is supported by the panel support member by sliding the liquid crystal panel relative to the panel support member and engaging it with the pair of engagement portions.

[0012] The above-mentioned "image projection device" is not particularly limited in its specific use as long as it is configured to project a display image on an image display unit, and can be used, for example, as an in-vehicle head-up display.

[0013] The specific configuration of the above-mentioned "image display unit" is not particularly limited as long as it is configured to project a display image, and for example, a translucent plate arranged on the front window of the vehicle or on the inside of the passenger compartment can be used.

[0014] The "reflecting mirror" is not particularly limited in its specific shape or arrangement as long as it is configured to reflect the light emitted from the image generating unit toward the image display section.

[0015] The "opening" is not particularly limited in its specific shape, so long as it is formed so as to allow the backlight emitted from the optical unit to pass through toward the reflecting mirror.

[0016] The above-mentioned "panel support member" is configured so that a pair of engagement portions are formed at locations located on either side of the opening, but the specific orientation of the "both sides" of the opening is not particularly limited, and for example, both the left and right sides or both the top and bottom sides can be used.

[0017] The "pair of engaging portions" are not particularly limited in their specific shapes or arrangements, so long as they are configured to engage with both side edges of the liquid crystal panel when it is slid. Effect of the Invention

[0018] The image projection device of the present invention is configured to reflect the light emitted from the image generating unit toward the image display section by a reflecting mirror. The image generating unit includes a liquid crystal panel, an optical unit that illuminates the liquid crystal panel with backlight, and a panel support member that supports the liquid crystal panel. In addition, the panel support member is formed with an opening that allows the backlight illumination light from the optical unit to pass through toward the reflecting mirror, so that the backlight illumination light from the optical unit can easily reach the reflecting mirror via the liquid crystal panel.

[0019] In this case, a pair of engagement portions that engage with both side edges of the liquid crystal panel are formed in the portions located on either side of the opening in the panel support member, and the liquid crystal panel is supported by this panel support member by sliding the liquid crystal panel relative to the panel support member to engage with the pair of engagement portions, thereby obtaining the following advantageous effects.

[0020] In other words, in order to position the liquid crystal panel with high positional accuracy relative to the optical unit, the configuration of the panel support member can be simplified compared to a configuration in which a pair of support members are arranged on both the front and back of the liquid crystal panel and are screwed and fixed at multiple locations, as in the hypothetical example described above, and this makes it possible to construct an image projection device at low cost.

[0021] Thus, according to the present invention, in an image projection device configured to project a display image onto an image display section using light emitted from an image generating unit, the liquid crystal panel of the image generating unit can be positioned with high positional accuracy relative to the optical unit using an inexpensive configuration.

[0022] In the above configuration, if each of the pair of engaging portions is configured such that a front abutment portion that abuts against the front surface of the liquid crystal panel and a rear abutment portion that abuts against the rear surface of the liquid crystal panel are alternately formed at different positions relative to the sliding direction of the liquid crystal panel, the configuration can be easily molded as a panel support member, and the liquid crystal panel can be efficiently clamped from both the front and rear sides.

[0023] In this case, if each of the pair of engaging portions is configured so that front contact portions and rear contact portions are formed at a plurality of positions in the sliding direction, the following advantageous effects can be obtained.

[0024] In other words, when the liquid crystal panel has both side edges engaged with the pair of engagement parts, it receives a pressing force from the front side of the device when it abuts against the front abutment part, and receives a pressing force from the rear side of the device when it abuts against the rear abutment part. Therefore, there is a risk that the liquid crystal panel will be bent and deformed due to the opposite pressing forces acting on different positions in the sliding direction.

[0025] In contrast, by configuring each of the pair of engagement parts so that the front contact part and the rear contact part are formed at multiple locations in the sliding direction, the pressing force from the front side of the device and the pressing force from the rear side of the device can be dispersed and reduced to multiple locations in the sliding direction, thereby minimizing the risk of bending deformation of the liquid crystal panel supported by the panel support member.

[0026] In the above configuration, if the panel support member is further configured so that a positioning portion is formed at a portion located forward of the opening in the sliding direction, which positions the liquid crystal panel in the sliding direction by abutting against the front edge of the liquid crystal panel in the sliding direction, the positioning accuracy of the liquid crystal panel can be improved.

[0027] Furthermore, in this case, if the panel support member is configured to have a holding structure at a portion located rearward of the opening in the sliding direction, which holds the liquid crystal panel in a position relative to the sliding direction by engaging with the rear edge of the liquid crystal panel in the sliding direction, the liquid crystal panel can be maintained in a stably positioned state relative to the panel support member. [Brief description of the drawings]

[0028] [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. [Diagram 2] View from the direction of arrow II in Figure 1 [Diagram 3] Detailed view of part III in Fig. 1 [Figure 4] Cross-sectional view of line IV-IV in Figure 3 [Diagram 5] FIG. 4 is a front view showing a state in which a liquid crystal panel is attached to a panel support member in the image projection device. [Figure 6] A cross-sectional view of the above assembly taken along line VI-VI in Figure 5. [Figure 7] FIG. 13 is a perspective view showing the above assembly. [Figure 8] FIG. 8 is a view similar to FIG. 7, showing a first modified example of the embodiment. [Figure 9] FIG. 7 is a view similar to FIG. 5, showing a second modification of the embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0030] 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 seen in the direction of the arrow II in Fig. 1.

[0031] 1 and 2, the direction indicated by X is the "forward" of the image projection device 10 (also the "forward" of the vehicle), the direction indicated by Y is the "leftward" direction perpendicular to the "forward", and the direction indicated by Z is the "upward" direction. This is the same in other figures besides FIG. 1 and 2.

[0032] As shown in FIGS. 1 and 2, the image projection device 10 of this embodiment is an in-vehicle head-up display, and is configured to project a display image PIC as a virtual image on an image display unit 102A set on the inner surface of a front windshield 102 when placed in the passenger compartment of a vehicle 100.

[0033] An optical path R shown in FIG. 1 is an optical path when the driver 2 visually recognizes the display image PIC projected on the image display unit 102A by the image projection device 10. As shown in FIG.

[0034] 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. This allows the driver 2 of the vehicle 100 to easily visually recognize the display image PIC projected on the image display unit 102A.

[0035] In FIG. 2, as a specific example of the display image PIC, a state in which the vehicle speed (50 Km / h) is displayed together with a left-pointing arrow is shown.

[0036] The image projection device 10 is disposed so as to be located in front of the steering wheel 104 and in the vicinity of the lower part of the windshield 102 .

[0037] As shown in FIG. 1, the image projection device 10 includes an image generating unit 20 that generates a display image that is the basis for the display image PIC, a reflector 40 that reflects the light emitted from the image generating unit 20 toward the image display section 102A of the front window 102, a housing 50 that accommodates the image generating unit 20 and the reflector 40, and a translucent cover 60 attached to the housing 50.

[0038] 3 is a detailed view of a portion III in FIG. 1, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

[0039] 3, the housing 50 has a configuration in which a first housing 52 formed to open upward is fitted with a second housing 54. Specifically, the second housing 54 has an outer peripheral flange portion 54b, and is fitted to the first housing 52 with the outer peripheral flange portion 54b in contact with an upper end surface of a peripheral wall portion 52a of the first housing 52.

[0040] The first and second housings 52 and 54 are both made of opaque resin moldings. The second housing 54 has an upper opening 54a formed therein for transmitting the light reflected by the reflecting mirror 40 toward the image display unit 102A.

[0041] The light-transmitting cover 60 is made of a colorless and transparent resin panel. The light-transmitting cover 60 is arranged to cover the upper opening 54a of the second housing 54 in a state where it is curved downward and inclined slightly upward toward the rear of the device. The light-transmitting cover 60 allows the emitted light from the image generating unit 20 reflected by the reflecting mirror 40 to enter the image display section 102A, while ensuring the dustproofness of the internal space 12 of the housing 50.

[0042] The second housing 54 is formed with a light-shielding piece 54c that extends obliquely downward and forward from the rear end edge of the upper 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 light-transmitting cover 60 from reaching the image generating unit 20 as direct light.

[0043] The image generating unit 20 is arranged in a rear region of the interior space 12 and the reflector 40 is arranged in a front region of the interior space 12 .

[0044] The reflecting mirror 40 is configured as a concave mirror, and the reflecting surface 40a has a horizontally elongated rectangular shape when viewed from the front of the device. The image generating unit 20 is disposed so as to be located at the center of the reflecting mirror 40 in the left-right direction.

[0045] The image generating unit 20 includes a liquid crystal panel 22 and an optical unit 30 that irradiates the liquid crystal panel 22 with backlight from its rear side (i.e., the rear side of the device). The image generating unit 20 is configured to generate a display image (i.e., an image that is the source of the display image PIC) on the liquid crystal panel 22 by using backlight irradiation light from the optical unit 30.

[0046] The optical unit 30 includes a light-emitting element 32 as a light source, a substrate 34 on which the light-emitting element 32 is mounted, a lens 36 that controls the deflection of the light emitted from the light-emitting element 32, and a lens holder 38 that supports the lens 36.

[0047] The lens 36 has a vertical cross-sectional shape like a biconvex lens and a horizontal cross-sectional shape like a plano-convex lens, which allows the backlight emitted from the optical unit 30 to efficiently enter the reflecting surface 40a of the reflecting mirror 40 via the liquid crystal panel 22. The lens 36 is supported by a lens holder 38 at its outer circumferential flange portion 36a.

[0048] The substrate 34 is supported at its rear surface by the heat sink 24 in a state in which it is disposed along a vertical plane perpendicular to the front-rear direction of the device so that the light emitting surface of the light emitting element 32 faces the front direction of the device.

[0049] The heat sink 24 includes a main body 24A extending in a flat plate shape along a vertical plane perpendicular to the front-rear direction of the device, and a plurality of heat dissipation fins 24B extending from the main body 24A toward the rear of the device at intervals in the left-right direction. The heat sink 24 is supported by a lens holder 38 at the main body 24A.

[0050] The liquid crystal panel 22 has a horizontally elongated rectangular outer shape, and is supported by a panel support member 70 in a state inclined forward with respect to a vertical plane perpendicular to the front-to-rear direction of the device (the specific support structure will be described later).

[0051] The panel support member 70 is disposed so as to cover the optical unit 30 from the front side of the device. The panel support member 70 is formed with an opening 70a for allowing the backlight irradiation light from the optical unit 30 to pass through toward the reflecting mirror 40. The opening 70a has a horizontally elongated rectangular opening shape.

[0052] As shown in FIG. 4, the image generating unit 20 is supported by the first housing 52 by fastening the optical unit 30 and the panel supporting member 70 to the first housing 52 at both left and right ends thereof with screws.

[0053] Specifically, tab-shaped mounting parts 38a extending along a vertical plane perpendicular to the front-rear direction of the device are formed on both left and right sides of the lens holder 38. Tab-shaped mounting parts 70b extending along a vertical plane perpendicular to the front-rear direction of the device are also formed on both left and right sides of the panel support member 70, and boss parts 70c are formed on the mounting parts 70b. With the pair of left and right mounting parts 38a, 70b of the lens holder 38 and the panel support member 70 overlapping each other, they are brought into contact with the peripheral wall part 52a of the first housing 52 from the front side of the device, and further, in this state, the screw 46 is fastened to the boss part 70c of the panel support member 70 via the mounting part 38a of the lens holder 38 from the rear side of the device, thereby screwing and fixing to the first housing 52.

[0054] As shown in FIG. 4, the reflecting mirror 40 is supported so as to be rotatable about an axis Ax that extends in the left-right direction relative to the first housing 52.

[0055] An actuator 42 for rotating the reflecting mirror 40 about the axis Ax is fixed to the first housing 52. This fixing is performed by fastening screws 44 to the bottom wall portion 52b of the first housing 52 at tab-shaped mounting portions 42b formed at two locations on the actuator 42.

[0056] The reflecting mirror 40 has vertical flanges 40b formed so as to protrude from both left and right sides of the rear surface of the reflecting surface 40a (i.e., the surface on the front side of the device) toward the rear side, and a pair of left and right shafts 40c, 40d protruding outward in the left-right direction along the axis Ax are formed on the pair of left and right vertical flanges 40b. The left shaft 40c (right side when viewed from the front of the device) is placed on a placement portion 52c formed on the inner surface of a peripheral wall portion 52a of the first housing 52, and the right shaft 40d is directly connected to the output shaft 42a of the actuator 42.

[0057] The mounting portion 52c has an approximately U-shaped mounting surface, and the second housing 54 is formed with an abutment portion (not shown) for abutting from above against the shaft portion 40c mounted on the mounting portion 52c to position the reflector 40.

[0058] Next, a specific support structure for the liquid crystal panel 22 by the panel support member 70 will be described.

[0059] FIG. 5 is a front view showing how the liquid crystal panel 22 is assembled to the panel support member 70, FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5 showing the assembly, and FIG. 7 is a perspective view showing the assembly.

[0060] 5 to 7, the panel support member 70 is configured such that a pair of engagement portions 72 that engage with both side edges of the liquid crystal panel 22 are formed in portions located on the left and right sides of the opening 70a. The liquid crystal panel 22 is supported by the panel support member 70 by sliding the liquid crystal panel 22 from its lower side relative to the panel support member 70 to engage with the pair of left and right engagement portions 72.

[0061] Each of the pair of left and right engagement portions 72 is configured by a front abutment portion 72A that abuts against the front surface of the liquid crystal panel 22 and a rear abutment portion 72B that abuts against the rear surface of the liquid crystal panel 22, which are alternately formed at different positions in the sliding direction of the liquid crystal panel 22 (i.e., positions that do not overlap with each other when viewed from the front of the device).

[0062] Specifically, the front contact portion 72A is formed at the center of the opening 70a in the up-down direction, and the rear contact portion 72B is formed at both the up-down and down-down ends of the opening 70a. At this time, the distance in the front-to-rear direction of the device between the front contact portion 72A and the pair of upper and lower rear contact portions 72B is set to a value slightly larger than the plate thickness of the liquid crystal panel 22. Also, the front contact portion 72A is set to a value such that the amount of protrusion toward the opening 70a side is slightly smaller than the pair of upper and lower rear contact portions 72B (note that a configuration in which this setting is not set can also be adopted).

[0063] A positioning portion 74 is formed in the panel support member 70 at a portion located forward (i.e., above) the opening 70a in the sliding direction, for positioning the liquid crystal panel 22 in the sliding direction by abutting against the sliding direction front end edge of the liquid crystal panel 22. Specifically, the positioning portion 74 is formed so as to extend horizontally as the upper end surface of the opening 70a.

[0064] The panel support member 70 is provided with a holding structure 76 at a position located rearward (i.e., downward) from the opening 70a in the sliding direction, which holds the liquid crystal panel 22 in a position relative to the sliding direction by engaging with the rear end edge of the liquid crystal panel 22 in the sliding direction.

[0065] The holding structure 76 is composed of a pair of left and right locking pieces 76A extending in an L-shape from a pair of left and right rear contact portions 72B formed at the lower end positions of the opening 70a.

[0066] The pair of left and right locking pieces 76A are formed so as to extend from the pair of left and right rear contact portions 72B in directions approaching each other toward the opening 70a, and then extend rearward in the sliding direction. At this time, the pair of left and right locking pieces 76A are formed in a flat plate shape with a thickness thinner than the pair of left and right rear contact portions 72B, but the front surface of the tip portion 76Aa is formed in a convex shape.

[0067] As shown in FIG. 6(a), when the liquid crystal panel 22 is slid upward relative to the panel support member 70, the pair of left and right locking pieces 76A are adapted to flex and deform with their tip ends 76Aa in contact with the rear surface of the liquid crystal panel 22, and further, as shown in FIG. 6(b), when the liquid crystal panel 22 is slid to a position where it abuts against the positioning portion 74 of the panel support member 70, the tip ends 76Aa of the pair of left and right locking pieces 76A are adapted to engage with the rear edge portion of the liquid crystal panel 22 in the sliding direction.

[0068] The panel support member 70 is formed so that its lower edge portion 70d, located below the opening 70a, extends horizontally with the same thickness as the pair of left and right rear abutment portions 72B, while the portions adjacent to the tip portions 76Aa of the pair of left and right engaging pieces 76A are formed concavely so as to surround the tip portions 76Aa.

[0069] Next, the operation of this embodiment will be described.

[0070] The image projection device 10 of this embodiment is configured to reflect the light emitted from the image generating unit 20 toward the image display section 102A by the reflecting mirror 40. The image generating unit 20 includes a liquid crystal panel 22, an optical unit 30 that performs backlight irradiation onto the liquid crystal panel 22, and a panel support member 70 that supports the liquid crystal panel 22. In addition, the panel support member 70 is formed with an opening 70a for passing the backlight irradiation light from the optical unit 30 toward the reflecting mirror 40. This makes it easy for the backlight irradiation light from the optical unit 30 to reach the reflecting mirror 40 via the liquid crystal panel 22.

[0071] In this case, a pair of left and right engagement portions 72 that engage with both side edges of the liquid crystal panel 22 are formed in the panel support member 70 at locations located on both the left and right sides of the opening 70a, and the liquid crystal panel 22 is supported by this panel support member 70 by sliding the liquid crystal panel 22 relative to the panel support member 70 to engage with the pair of left and right engagement portions 72, so that the following effects can be obtained.

[0072] That is, in order to position the liquid crystal panel 22 with high positional accuracy relative to the optical unit 30, the configuration of the panel support member 70 can be simplified compared to a configuration in which a pair of left and right support members arranged on both the front and rear sides of the liquid crystal panel 22 are screwed and fixed at multiple locations, as in the hypothetical example described above, and thus the image projection device 10 can be constructed at low cost.

[0073] Thus, according to this embodiment, in the image projection device 10 configured to project a display image PIC on the image display section 102A using light emitted from the image generation unit 20, the liquid crystal panel 22 of the image generation unit 20 can be positioned with high positional accuracy relative to the optical unit 30 using an inexpensive configuration.

[0074] In this embodiment, each of the pair of left and right engagement portions 72 is configured such that a front abutment portion 72A that abuts against the front surface of the liquid crystal panel 22 and a rear abutment portion 72B that abuts against the rear surface of the liquid crystal panel 22 are alternately formed at different positions in the sliding direction of the liquid crystal panel 22. This makes it possible to easily mold the panel support member 70 and efficiently clamp the liquid crystal panel 22 from both the front and rear sides.

[0075] Furthermore, in the panel support member 70 of this embodiment, a positioning portion 74 is formed at a portion located forward in the sliding direction from the opening 70a, which positions the liquid crystal panel 22 in the sliding direction by abutting against the front edge portion of the liquid crystal panel 22 in the sliding direction, thereby improving the positioning accuracy of the liquid crystal panel 22.

[0076] Furthermore, the panel support member 70 of this embodiment is provided with a holding structure 76 at a portion located rearward in the sliding direction from the opening 70a, which holds the liquid crystal panel 22 positioned in the sliding direction by engaging with the rear edge of the liquid crystal panel 22 in the sliding direction, so that the liquid crystal panel 22 can be maintained in a stably positioned state relative to the panel support member 70.

[0077] Moreover, this retaining structure 76 is composed of a pair of left and right locking pieces 76A, and when the liquid crystal panel 22 is slid upward relative to the panel support member 70, the left and right locking pieces 76A flex and deform with their tip portions 76Aa abutting the rear surface of the liquid crystal panel 22. Furthermore, when the liquid crystal panel 22 is slid to a position where it abuts against the positioning portion 74 of the panel support member 70, the tip portion 76Aa engages with the rear edge portion of the liquid crystal panel 22 in the sliding direction. Therefore, the liquid crystal panel 22 can be easily attached to the panel support member 70 while maintaining a stably positioned state.

[0078] Furthermore, in this embodiment, the liquid crystal panel 22 is supported by the panel support member 70 in a state tilted forward with respect to a vertical plane perpendicular to the front-to-rear direction of the device, so that sunlight S entering the internal space 12 of the housing 50 and reflected by the reflector 40 can be prevented from reflecting off the liquid crystal panel 22 and becoming stray light in a direction along the optical path R, and the sunlight S can be effectively prevented from reaching the image generation unit 20 as direct light.

[0079] In the above embodiment, the liquid crystal panel 22 is described as being configured to slide from the below relative to the panel support member 70, but it is also possible to configure it to slide from another direction (for example, from above or to the left or right).

[0080] In the above embodiment, the image projection device 10 has been described as having a single reflector 40, but it is also possible to configure the image projection device 10 to have a plurality of reflectors that sequentially reflect the light emitted from the image generation unit 20 toward the image display section 102A of the front window 102. Even when such a configuration is adopted, it is possible to obtain the same effect as in the above embodiment.

[0081] In the above embodiment, the image display unit 102A is described as being set on the inner surface of the front window 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 compartment of the front window 102.

[0082] 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.

[0083] Next, a modification of the above embodiment will be described.

[0084] First, a first modification of the above embodiment will be described.

[0085] FIG. 8 is a view similar to FIG. 7, showing a panel support member 170 of an image projection device according to this modified example.

[0086] As shown in FIG. 8, the panel support member 170 of this modified example also has a pair of left and right engagement portions 172 each configured such that a front abutment portion 172A that abuts against the front surface of the liquid crystal panel 22 and a rear abutment portion 172B that abuts against the rear surface of the liquid crystal panel 22 are alternately formed at different positions with respect to the sliding direction of the liquid crystal panel 22.

[0087] In addition, in panel support member 170 of this modified example, a positioning portion 174 is formed in a portion located forward of opening 170a in the sliding direction, and a retaining structure 176 is provided in a portion located rearward of opening 170a in the sliding direction, but the configuration of retaining structure 176 is different from that of the above embodiment.

[0088] That is, the holding structure 176 of this modified example is composed of a pair of left and right wedge-shaped protrusions 176A formed on the front lower end portions of the pair of left and right rear contact portions 172B located on the lower side. Each of the pair of left and right wedge-shaped protrusions 176A has a surface shape that gently slopes toward the rear side in the sliding direction and steeply slopes toward the front side in the sliding direction.

[0089] When the liquid crystal panel 22 is slid upward relative to the panel support member 170, the rear end portion in the sliding direction rides over the pair of left and right wedge-shaped protrusions 176A and engages with them.

[0090] When the configuration of this modified example is adopted, compared to the above embodiment, a slight load is applied when the liquid crystal panel 22 is slid upward due to contact with the pair of left and right wedge-shaped protrusions 176A; however, it is possible to obtain substantially the same effect as in the above embodiment while simplifying the configuration of the panel support member 170.

[0091] Next, a second modification of the above embodiment will be described.

[0092] FIG. 9 is a view similar to FIG. 5, showing a panel support member 270 of an image projection device according to this modified example.

[0093] As shown in FIG. 9, the basic configuration of a panel support member 270 according to this modification is similar to that of the above embodiment, but the configuration of a pair of left and right engagement portions 272 is partially different from that of the above embodiment.

[0094] That is, the pair of left and right engagement portions 272 in the panel support member 270 of this modified example is configured such that front contact portions 272A and rear contact portions 272B are alternately formed at multiple locations in the sliding direction. Specifically, the front contact portions 272A are formed at three locations in the sliding direction, and the rear contact portions 272B are formed at four locations in the sliding direction. At this time, the three front contact portions 272A and the four rear contact portions 272B are formed at positions that do not overlap with each other when viewed from the front of the device.

[0095] Also in panel support member 270 according to this modification, a holding structure 276 substantially similar to that in the above embodiment is provided in a portion located rearward (ie, downward) from opening 270a in the sliding direction.

[0096] That is, the holding structure 276 is composed of a pair of left and right locking pieces 276A extending in an L-shape from a pair of left and right rear surface abutment parts 272B formed at the lower end positions of the opening 270a. When the liquid crystal panel 22 is slid upward relative to the panel support member 270, the pair of left and right locking pieces 276A are flexed and deformed, and their tip ends 276Aa come into contact with the rear surface of the liquid crystal panel 22, and then engage with the rear edge of the liquid crystal panel 22 in the sliding direction.

[0097] However, in the retaining structure 276 of this modified example, the pair of left and right locking pieces 276A are formed to be shorter than those in the above embodiment (it is also possible to adopt a configuration in which they are not formed in this manner).

[0098] Even when the configuration of this modified example is adopted, substantially the same effects as those of the above embodiment can be obtained.

[0099] In addition, in this modified example, each of the pair of left and right engagement portions 272 is configured so that front abutment portions 272A and rear abutment portions 272B are formed at multiple locations in the sliding direction, thereby obtaining the following advantageous effects.

[0100] That is, when both side edges of the liquid crystal panel 22 are engaged with the pair of left and right engagement portions 272, the liquid crystal panel 22 receives a pressing force from the front side of the device due to abutment with the front abutment portion 272A, and receives a pressing force from the rear side of the device due to abutment with the rear abutment portion 272B. Therefore, there is a risk that the liquid crystal panel 22 may be bent and deformed due to the opposite pressing forces acting on different positions in the sliding direction.

[0101] In this respect, as in this modified example, by configuring each of the pair of left and right engagement parts 272 so that the front contact parts 272A and the rear contact parts 272B are alternately formed at multiple locations in the sliding direction, the pressing force from the front side of the device and the pressing force from the rear side of the device can be dispersed and reduced to multiple locations in the sliding direction. Therefore, the risk of bending deformation occurring in the liquid crystal panel 22 supported by the panel support member 270 can be minimized.

[0102] In the above-mentioned second modified example, it has been described that the front abutment portions 272A are formed in three locations and the rear abutment portions 272B are formed in four locations, but it is also possible to configure the locations of formation to be set to values ​​other than these.

[0103] It should be noted that the numerical values ​​given 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.

[0104] 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]

[0105] 2 Driver 10. Image projection device 12 Interior Space 20 Image Generation Unit 22 Liquid crystal panel 24 Heat sink 24A Main unit 24B Heat dissipation fin 30 Optical Unit 32 Light emitting element 34 Substrate 36 Lenses 36a Outer periphery flange 38 Lens holder 38a Mounting part 40 Reflector 40a reflective surface 40b Vertical flange section 40c, 40d shaft part 42 Actuator 42a Output shaft 42b Mounting part 44, 46 Screws 50 Housing 52 1st Housing 52a Peripheral wall part 52b Lower wall part 52c Placement part 54 Second Housing 54a Top opening 54b Outer periphery flange 54c Light shielding piece 60 Translucent cover 70, 170, 270 Panel support member 70a, 170a, 270a opening 70b Mounting part 70c boss part 70d Lower edge 72, 172, 272 Engagement part 72A, 172A, 272A Front contact part 72B, 172B, 272B Rear contact part 74, 174 Positioning part 76, 176, 276 holding structure 76A, 276A locking piece 76Aa, 276Aa tip 100 vehicles 102 Front window 102A Image display section 104 Steering Wheel 176A Cuneiform projection Axial line Image for PIC display R optical path S sunlight

Claims

1. In an image projection device configured to project a display image on an image display unit, an image generating unit that generates the display image; and a reflecting mirror that reflects light emitted from the image generating unit toward the image display unit, the image generating unit includes a liquid crystal panel, an optical unit that irradiates the liquid crystal panel with a backlight, and a panel support member that supports the liquid crystal panel; an opening is formed in the panel support member to allow backlight irradiation light from the optical unit to pass through toward the reflecting mirror; a pair of engagement portions that engage with both side edges of the liquid crystal panel are formed in the panel support member at portions located on both sides of the opening, an image projection device, wherein the liquid crystal panel is supported by the panel support member by sliding the liquid crystal panel relative to the panel support member and engaging with the pair of engaging portions.

2. The image projection device described in claim 1, characterized in that each of the pair of engagement portions is configured by a front abutment portion that abuts against the front surface of the liquid crystal panel and a rear abutment portion that abuts against the rear surface of the liquid crystal panel being alternately formed at different positions with respect to the sliding direction of the liquid crystal panel.

3. 3. The image projection device according to claim 2, wherein each of the pair of engagement portions has the front contact portion and the rear contact portion formed at a plurality of positions in the sliding direction.

4. The image projection device according to any one of claims 1 to 3, characterized in that a positioning portion is formed in a portion of the panel support member that is located forward of the opening in the sliding direction, the positioning portion abutting against the front end edge of the liquid crystal panel in the sliding direction to position the liquid crystal panel in the sliding direction.

5. 5. The image projection device according to claim 4, further comprising a holding structure provided at a portion of the panel support member that is located rearward in the sliding direction from the opening, the holding structure holding the liquid crystal panel in a position relative to the sliding direction by engaging with a rear end edge of the liquid crystal panel in the sliding direction.

Images