Image irradiation device

Abstract

To provide an image projecting device configured to project a display image on an image display part, which can project the display image on a proper position, with an inexpensive structure.SOLUTION: A housing 50 which houses first and second reflecting mirrors 30 and 40 that sequentially reflect light emitted from an image forming unit toward an image display part has a structure in which a second housing 54 is assembled to a first housing 52. Besides, placement parts 52h and 52j on which first and second shaft parts 44A and 44B formed at end parts at both sides of a reflecting surface 40a in the second reflecting mirror 40 are formed in the first housing 52. Further, in the second housing 54, contact parts 54c and 54d which contact a base end part 46a of a lever member 46, fixed to the first shaft part 44A and the second shaft part 44B, to position the second reflecting mirror 40. This can turn the second reflecting mirror 40 to enable a direction of the mirror to be adjusted.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an image projection device configured to project a display image on an image display unit. [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 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 as comprising an image generation unit that generates an image for display, a reflector that reflects light emitted from the image generation unit toward an image display unit, and a housing that contains the reflector. [Prior art documents] [Patent documents]

[0004] [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, it is preferable to have a configuration in which the orientation of the reflecting mirror is adjustable so that the display image is projected at an appropriate position on the image display unit.

[0006] In this case, if a bracket is attached to the reflector to support it rotatably, and this bracket is then fixed to the housing, it will be possible to adjust the orientation of the reflector.

[0007] However, when such a configuration is adopted, it becomes necessary to provide a new bracket, which increases the number of parts and therefore the cost of the image projection device.

[0008] It should be noted that this 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 unit, which is capable of projecting a display image at an appropriate position with an inexpensive configuration. [Means for solving the problem]

[0010] The present invention is intended to achieve the above object by devising a housing structure.

[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, the display device includes an image generating unit that generates the display image, a reflecting mirror that reflects light emitted from the image generating unit toward the image display unit, and a housing that accommodates the reflecting mirror, The housing is configured by assembling a first housing and a second housing, a shaft portion extending in a direction away from the reflecting surface is formed at a side end portion of the reflecting surface of the reflecting mirror, a mounting portion for mounting the shaft portion is formed in the first housing, The second housing is characterized in that an abutment portion is formed on the second housing to abut on the shaft portion placed on the placement portion to position the reflecting mirror.

[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 display an image for display, and for example, a translucent plate placed on the front window of a vehicle or the inside of the passenger compartment can be used.

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

[0015] The "shaft" may be formed on both side ends of the reflecting surface, or on either one of the side ends.

[0016] The "mounting portion" is not particularly limited in its specific shape as long as it has a shape that allows the shaft portion to be mounted thereon.

[0017] The specific shape of the "contact portion" is not particularly limited as long as it has a shape that allows the reflecting mirror to be positioned by contacting the shaft portion placed on the placement portion. [Effects of the Invention]

[0018] The image projection device of the present invention comprises an image generation unit that generates an image for display, a reflector that reflects light emitted from the image generation unit toward an image display unit, and a housing that contains the reflector.The housing is configured by assembling a first housing and a second housing, and the side end of the reflecting surface of the reflector is formed with an axis portion that extends in a direction away from the reflecting surface.The first housing is formed with a mounting portion for placing the axis portion, and the second housing is formed with an abutment portion for abutting against the axis portion placed on the mounting portion to position the reflector, thereby achieving the following effects.

[0019] That is, by configuring the housing in such a way that the first housing and the second housing are assembled together, it becomes possible to manufacture the housing without difficulty.

[0020] Furthermore, the shaft portion of the reflector is placed on the mounting portion of the first housing, and the second housing is assembled to this first housing, so that the reflector can be positioned in a direction perpendicular to the rotation axis without hindering its rotation, with the abutment portion abutting against the shaft portion placed on the mounting portion.

[0021] Therefore, it is possible to adjust the orientation of the reflector without the need to provide a new bracket or the like to rotatably support the reflector, thereby making it possible to project the display image at the appropriate position on the image display unit.

[0022] Moreover, this can be achieved by a simple operation of placing the reflecting mirror on the first housing and assembling the second housing.

[0023] As described above, according to the present invention, in an image projection device configured to project a display image on an image display section, the display image can be projected at an appropriate position with an inexpensive configuration.

[0024] In the above configuration, if the mounting portion of the first housing is further configured to be formed on the inner surface of the peripheral wall portion of the first housing, sufficient support rigidity for the reflecting mirror can be ensured.

[0025] In the above configuration, if the abutment portion of the second housing is further configured as a rib having an arc-shaped recess, the rotation of the reflector can be stabilized, thereby making it easy to adjust the orientation of the reflector.

[0026] In the above configuration, the shaft configuration further includes first and second shafts arranged on the same axis at both ends of the reflecting surface, and a lever member extending in a direction intersecting the axis is fixed to the second shaft, and this lever member is connected to an actuator for rotating the reflecting mirror around the axis, making it possible to rotate the reflecting mirror with the minimum number of necessary members.

[0027] In this case, if a second mounting portion for mounting the lever member is formed on the inner surface of the peripheral wall portion of the first housing, and if a mounting portion for mounting the second shaft portion is formed at a position closer to the first shaft portion than the lever member, the lever member will be supported on both sides by the first housing, allowing the reflector to rotate stably. [Brief explanation 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. [Figure 2] View in the direction of arrow II in Figure 1 [Figure 3] Detailed view of part III in Figure 1 [Figure 4] FIG. 1 is a plan view showing the image projection device with the second housing removed; [Figure 5] 5 is a cross-sectional view of the image projection device taken along line VV in FIG. [Figure 6] FIG. 10 is a perspective view showing a first reflecting mirror of the image projection device alone; [Figure 7] (a) is a cross-sectional view taken along line VIIa-VIIa in Figure 5, and (b) is a cross-sectional view taken along line VIIb-VIIb in Figure 5. [Figure 8] 4(a) is a view similar to FIG. 3 showing the detailed structure of the second housing, and FIG. 4(b) is a cross-sectional view taken along line bb in FIG. 4(a). [Figure 9] FIG. 10 is a perspective view showing the state of assembly of the image projection device. [Figure 10] FIG. 5 is a view similar to FIG. 4, showing a modification of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[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 this embodiment 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] In these figures, 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.

[0032] 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 display image PIC as a virtual image onto a display area 102A of a front window 102 serving as an image display unit when placed inside the cabin of a vehicle 100.

[0033] An optical path R shown in FIG. 1 is an optical path taken by the driver 2 when the display image PIC projected onto the display area 102A of the windshield 102 by the image projection device 10 is visually recognized by the driver 2. As shown in FIG.

[0034] The display area 102A is positioned in the lower area of the windshield 102 and in the area in front of the steering wheel 104, so that it can be easily visually recognized by the driver 2 of the vehicle 100. Note that Fig. 2 shows a specific example of the display image PIC in which the vehicle speed (50 km / h) is displayed together with an arrow pointing left.

[0035] 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 .

[0036] As shown in FIG. 1, the image projection device 10 includes an image generation unit 20 that generates an image that serves as the basis for the display image PIC, first and second reflectors 30, 40 that sequentially reflect light emitted from the image generation unit 20 toward the display area 102A of the front windshield 102, a housing 50 that accommodates the first and second reflectors 30, 40, and a translucent cover 60 attached to the housing 50.

[0037] The image generating unit 20 and the first and second reflectors 30, 40 are supported in a housing 50 (which will be described below).

[0038] The housing 50 is configured such that a first housing 52 is formed to open upward, and a second housing 54 is assembled to the first housing 52. Specifically, the second housing 54 has an outer peripheral flange portion 54b, and is assembled to the first housing 52 with the outer peripheral flange portion 54b abutting against an upper end opening 52a of the first housing 52.

[0039] 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 40 to pass through toward the display area 102A.

[0040] 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 reflected light from the second reflecting mirror 40 to enter the display area 102A, while ensuring dustproofness of the internal space 12 of the housing 50.

[0041] Fig. 3 is a detailed view of part III in Fig. 1. Fig. 4 is a plan view showing the image projection device 10 with the second housing 54 removed, and Fig. 5 is a cross-sectional view showing the image projection device 10 at the position of line VV in Fig. 4.

[0042] As shown in FIGS. 3 to 5, the first and second reflecting mirrors 30, 40 have reflective surfaces 30a, 40a that are symmetrical in shape, and the image generating unit 20 is disposed at the center in the left-right direction.

[0043] The image generating unit 20 includes a liquid crystal panel 22 having a rectangular outer shape. The image generating unit 20 is supported by the lower wall portion 52b of the first housing 52 with the longitudinal direction of the liquid crystal panel 22 extending in the left-right direction (i.e., the vehicle width direction) and with the liquid crystal panel 22 facing diagonally upward and rearward.

[0044] The image generating unit 20 is configured to generate an image that is the basis of the display image PIC on the liquid crystal panel 22 by irradiating the liquid crystal panel 22 with backlight from the rear side thereof.

[0045] A unit mounting portion 52d for mounting the image generating unit 20 is formed on the lower wall portion 52b of the first housing 52. A rectangular opening 52e that is slightly larger than the outer shape of the liquid crystal panel 22 is formed in this unit mounting portion 52d.

[0046] The image generating unit 20 is fixed to the lower wall portion 52b of the first housing 52 by screwing or the like, with the liquid crystal panel 22 being disposed so as to fit into the opening 52e of the unit mounting portion 52d.

[0047] The first reflecting mirror 30 is disposed diagonally above and behind the image generating unit 20, and is configured to reflect the light emitted from the image generating unit 20 forward.

[0048] FIG. 6 is a perspective view showing the first reflecting mirror 30 alone.

[0049] 6, the first reflecting mirror 30 is configured as a saddle-shaped reflecting mirror in which the surface shape of its reflecting surface 30a is a saddle-shaped curved surface. The reflecting surface 30a of the first reflecting mirror 30 has a substantially rectangular outer shape that extends in the left-right direction (i.e., the direction of the image that the driver 2 is desired to view) when viewed from the front of the vehicle.

[0050] Specifically, as shown by the dotted line in Figure 6, the horizontal cross-sectional shape of the reflecting surface 30a of the first reflecting mirror 30 (i.e., the cross-sectional shape along a first direction parallel to the long sides of the rectangle) is composed of a convex curve (specifically, a convex curve with an approximately arc-like shape), and the vertical cross-sectional shape (i.e., the cross-sectional shape along a second direction parallel to the short sides of the rectangle) is composed of a concave curve (specifically, a concave curve with an approximately arc-like shape).

[0051] The first reflecting mirror 30 has flanges 32 formed on both the left and right ends of its reflecting surface 30a. As shown in Fig. 4, the first reflecting mirror 30 is fixed to the first housing 52 at the pair of left and right flanges 32.

[0052] Specifically, each flange 32 includes a side wall 32A extending rearward along a vertical plane from the side edge of the reflecting surface 30a, and a stepped portion 32B extending laterally from the outer surface of the side wall 32A. The stepped portion 32B is configured such that an upper flat portion 32B1 and a lower flat portion 32B2 are connected via an inclined surface.

[0053] The first reflecting mirror 30 is positioned relative to the first housing 52 at the upper flat surface portions 32B1 of the stepped portions 32B of the pair of left and right flange portions 32, and is then fixed with screws at the lower flat surface portions 32B2.

[0054] To achieve this, a pair of left and right columnar protrusions 52f for supporting the first reflecting mirror 30 are formed on the bottom wall 52b of the first housing 52. Each columnar protrusion 52f is formed so as to protrude upward in a generally pyramidal shape from the bottom wall 52b of the first housing 52. The top end surface of each columnar protrusion 52f is formed in a horizontal plane, and a pin 52g protruding upward is formed on this top end surface.

[0055] Meanwhile, pin insertion holes 32B1a for inserting the pins 52g are formed in the upper flat surface portion 32B1 of the stepped portion 32B of each flange portion 32 of the first reflecting mirror 30. One of the pair of left and right pin insertion holes 32B1a (specifically, the left pin insertion hole 32B1a) is formed in a circular shape with approximately the same diameter as the pin 52g, and the other is formed in an oval shape extending in the left-right direction and with approximately the same front-to-rear width as the pin 52g.

[0056] Further, the lower flat surface portion 32B2 of the stepped portion 32B of each flange portion 32 is formed with a screw insertion hole 32B2a (see FIG. 6) for fastening the screw 34 to the lower wall portion 52b of the first housing 52.

[0057] The first reflecting mirror 30 is positioned and fixed relative to the first housing 52 by inserting a pair of left and right pins 52g into a pair of left and right pin insertion holes 32B1a, and pressing the pair of left and right upper flat surfaces 32B1 against the upper end surfaces of the pair of left and right columnar protrusions 52f, and then tightening screws 34 into a pair of left and right screw holes (not shown) formed in the lower wall portion 52b of the first housing 52 through a pair of left and right screw insertion holes 32B2a.

[0058] The pair of left and right columnar protrusions 52f have a peripheral shape that does not block the light reflected from the first reflecting mirror 30 toward the second reflecting mirror 40. Specifically, the pair of left and right columnar protrusions 52f have chamfered inner corners on the front surface of the quadrangular pyramid peripheral surface, thereby forming inclined surfaces 52f1 that extend forward on both the left and right sides. The formation of such inclined surfaces 52f1 on the columnar protrusions 52f prevents the light reflected from the first reflecting mirror 30 toward the second reflecting mirror 40 from being blocked by the columnar protrusions 52f.

[0059] In addition, a pair of left and right columnar protrusions 52f for supporting the first reflecting mirror 30 are formed on the first housing 52, thereby preventing stray light from being generated when the emitted light from the image generating unit 20 or sunlight S hits the flange portion 32 of the first reflecting mirror 30.

[0060] 3 to 5, the second reflecting mirror 40 is disposed in front of the first reflecting mirror 30. The second reflecting mirror 40 is configured to reflect the light emitted from the image generating unit 20 and reflected by the first reflecting mirror 30 upward.

[0061] The second reflecting mirror 40 is a concave mirror, and the surface shape of its reflecting surface 40a is configured as a substantially spherical concave curved surface. The reflecting surface 40a of this second reflecting mirror 40 has a rectangular outer shape extending in the left-right direction when viewed from the front of the vehicle. The reflecting surface 40a of the second reflecting mirror 40 is formed to be larger in size than the reflecting surface 30a of the first reflecting mirror 30, and is formed to have a larger aspect ratio than the reflecting surface 30a of the first reflecting mirror 30. Specifically, the reflecting surface 40a of the second reflecting mirror 40 has a vertical width that is approximately 1 to 1.5 times that of the reflecting surface 30a of the first reflecting mirror 30, and a horizontal width that is approximately 2 to 3 times that of the reflecting surface 30a of the first reflecting mirror 30.

[0062] In this way, the reflective surface 40a of the second reflecting mirror 40 is curved greatly in the left-right direction (i.e., the direction of the image that the driver 2 is desired to see) and is formed with a larger aspect ratio than the reflective surface 30a of the first reflecting mirror 30. However, since the first reflecting mirror 30 is configured as a saddle-shaped reflecting mirror, the reflected light from its reflective surface 30a has a small spread in the vertical direction and a large spread in the left-right direction, which allows the light to efficiently enter the reflective surface 40a of the second reflecting mirror 40.

[0063] 4 and 5, the second reflecting mirror 40 is supported by the first housing 52 so as to be rotatable about an axis Ax extending in the left-right direction near the front of the second reflecting mirror 40. This allows the angle of the second reflecting mirror 40 to be adjusted so that the reflected light from the first reflecting mirror 30 accurately strikes the display area 102A of the front windshield 102.

[0064] To achieve this, a pair of left and right brackets 42 extending forward along a vertical plane are formed on both left and right end portions on the rear side of the reflecting surface 40a of the second reflecting mirror 40. Each pair of left and right brackets 42 is formed with first and second shaft portions 44A, 44B extending in both left and right directions (i.e., directions away from the reflecting surface 40a) on the axis Ax.

[0065] The first and second shaft portions 44A, 44B are both formed in a cylindrical shape. The second shaft portion 44B located on the right side has a smaller outer diameter than the first shaft portion 44A located on the left side, but its tip portion has the same outer diameter as the first shaft portion 44A.

[0066] A base end portion 46a of a lever member 46 extending rearward is fixed to the tip end surface of the second shaft portion 44B. The base end portion 46a of the lever member 46 is formed to extend in a cylindrical shape coaxially with the second shaft portion 44B, and its outer diameter is set to the same value as the tip end portion of the second shaft portion 44B.

[0067] A tip end 46b of the lever member 46 is connected to an output shaft 48a of an actuator 48 for rotating the second reflecting mirror 40 about the axis Ax.

[0068] The actuator 48 is fixed to the lower wall portion 52b on the lower side of the first housing 52. The output shaft 48a of this actuator 48 is formed to extend upward into the internal space 12 of the housing 50 and is configured to be able to reciprocate in the up and down direction.

[0069] 7(a) is a cross-sectional view taken along line VIIa-VIIa in FIG. 5, and FIG. 7(b) is a cross-sectional view taken along line VIIb-VIIb in FIG.

[0070] As also shown in Figures 7(a) and (b), the peripheral wall portion 52c of the first housing 52 is formed with a mounting portion 52h for mounting the first shaft portion 44A and a mounting portion 52i for mounting the base end portion 46a of the lever member 46.

[0071] Mounting portion 52h is formed on the inner surface of the left region of peripheral wall portion 52c of first housing 52, and mounting portion 52i is formed on the inner surface of the right region of peripheral wall portion 52c of first housing 52. The upper surface of each of mounting portions 52h, 52i is formed in a substantially U-shape, and the lower end portion thereof is configured as a semi-cylindrical surface having an inner diameter substantially the same as the outer diameters of first shaft portion 44A and base end portion 46a of lever member 46.

[0072] Furthermore, a mounting portion 52j for mounting the second shaft portion 44B is formed on the first housing 52 to the left of the lever member 46 (i.e., on the first shaft portion 44A side). This mounting portion 52j is formed as a rib that protrudes upward from the bottom wall portion 52b of the first housing 52. The top surface of this mounting portion 52j is formed in a substantially U-shape, and its lower end portion is configured as a semi-cylindrical surface having an inner diameter that is substantially the same as the outer diameter of the second shaft portion 44B.

[0073] On the other hand, the second housing 54 is formed with an abutment portion 54c for abutting against the first shaft portion 44A placed on the mounting portion 52h of the first housing 52 to position the second reflecting mirror 40, and an abutment portion 54d for abutting against the base end portion 46a of the lever member 46 placed on the mounting portion 52i of the first housing 52 to position the second reflecting mirror 40.

[0074] Each abutment portion 54c, 54d is formed as a rib protruding downward from the outer peripheral flange portion 54b of the second housing 54, and a semi-cylindrical recess having an inner diameter approximately the same as the outer diameter of each of the first shaft portion 44A and the base end portion 46a of the lever member 46 is formed on its lower end surface.

[0075] Furthermore, a tab 46c that protrudes downward is formed on the base end 46a of the lever member 46, and a pair of left and right clamping portions 52k that protrude upward are formed on the lower wall portion 52b of the first housing 52. The tab 46c is formed to extend along a vertical plane that extends in the front-to-rear direction, and the pair of left and right clamping portions 52k are formed to be located on both left and right sides of the tab 46c. The second reflecting mirror 40 is positioned with respect to the first housing 52 in the left-right direction by engagement between the tab 46c and the pair of left and right clamping portions 52k.

[0076] As shown in Figures 3 to 5, the lower wall portion 52b of the first housing 52 is formed at a position one step higher than the portion where the unit mounting portion 52d is formed and the portion located below the reflecting surfaces 30a, 40a of the first and second reflecting mirrors 30, 40.

[0077] 3, the second housing 54 is formed with a light-shielding piece 54e that covers the peripheral area of the reflecting surface 30a of the first reflecting mirror 30. The light-shielding piece 54e is formed in a plate shape that extends obliquely downward and forward from the rear end edge of the opening 54a in the second housing 54.

[0078] In the image projection device 10, sunlight S entering the vehicle interior through the front window 102 may enter the internal space 12 of the housing 50 through the translucent cover 60, but this sunlight S is prevented from reaching the peripheral area of the reflecting surface 30a of the first reflecting mirror 30 by the shading action of the shading piece portion 54e.

[0079] This prevents sunlight S reaching this peripheral area from being reflected by the vapor-deposited film or the like and becoming stray light, even if a vapor-deposited film or the like adheres to the peripheral area of the reflecting surface 30a when performing surface treatment to form the reflecting surface 30a of the first reflecting mirror 30.

[0080] Figure 8(a) is a diagram similar to Figure 3, showing the detailed structure of the second housing 54. Figure 8(b) is a cross-sectional view taken along line bb in Figure 8(a).

[0081] As shown in Figures 8(a) and (b), the light-shielding piece portion 54e is formed so that its tip surface extends to a position below the upper edge of the reflecting surface 30a of the first reflecting mirror 30, and a notch portion 54e1 is formed at the tip to allow reflected light from the first reflecting mirror 30 to enter the second reflecting mirror 40.

[0082] The notch 54e1 is formed as a horizontally elongated rectangular recess in a front view of the vehicle. The upper edge of the notch 54e1 is located slightly below the upper edge of the reflecting surface 30a of the first reflecting mirror 30, and both side edges of the notch 54e1 are slightly spaced apart on both sides from the left and right end edges of the reflecting surface 30a of the first reflecting mirror 30 (i.e., the upper edge and both side edges are located on the outer periphery of the optically effective range of the reflecting surface 30a of the first reflecting mirror 30).

[0083] The light-shielding piece 54e is formed in a plate-like shape so as to wrap around to portions located on both the left and right sides of the opening 54a in the second housing 54. In this case, the light-shielding piece 54e is formed so as to extend diagonally downward toward the inner periphery on both the left and right sides of the opening 54a, with its front edge located rearward of the second reflecting mirror 40. By giving the light-shielding piece 54e a reasonable shape in the mold removal direction, it is possible to prevent the mold from becoming too complicated.

[0084] FIG. 9 is a perspective view showing how the image projection device 10 is assembled.

[0085] As shown in FIG. 9, the image projection device 10 is assembled by sequentially attaching the second reflecting mirror 40 and the second housing 54 to the first housing 52 from above.

[0086] In FIG. 9, the first housing 52 is shown with the first reflecting mirror 30 and the actuator 48 already attached, and the second reflecting mirror 40 is shown with the light-transmitting cover 60 already attached.

[0087] The second reflector 40 is attached to the first housing 52 by placing the first shaft portion 44A of the second reflector 40 on the mounting portion 52h of the first housing 52, and by placing the base end portion 46a of the lever member 46 and the second shaft portion 44B of the second reflector 40 on the mounting portions 52i, 52j of the first housing 52.

[0088] At this time, the tab 46c formed on the base end 46a of the lever member 46 is inserted between a pair of left and right clamping portions 52k of the first housing 52, and the tip end 46b of the lever member 46 is connected to the output shaft 48a of the actuator 48.

[0089] The second housing 54 is attached to the first housing 52 by lance engagement at multiple locations. To achieve this, downward lances 54f are formed in multiple locations on the outer peripheral flange portion 54b of the second housing 54, and engagement holes 52m that open in the vertical direction are formed in the first housing 52 at positions corresponding to the lances 54f. When the outer peripheral flange portion 54b of the second housing 54 abuts against the upper end opening 52a of the first housing 52, each lance 54f is inserted into and engages with each engagement hole 52m, thereby fixing the second housing 54 to the first housing 52.

[0090] Next, the operation of this embodiment will be described.

[0091] The image projection device 10 of this embodiment comprises an image generation unit 20 that generates a display image PIC, first and second reflecting mirrors 30, 40 that sequentially reflect the light emitted from this image generation unit 20 toward the front window 102 as an image display unit, and a housing 50 that accommodates these.Since the first and second shaft portions 44A, 44B are arranged on the same axis Ax at both side ends of the reflecting surface 40a of the second reflecting mirror 40, it is possible to adjust the orientation of the second reflecting mirror 40 by rotating the second reflecting mirror 40 around the axis Ax.

[0092] In this case, since the housing 50 is configured such that the second housing 54 is assembled to the first housing 52 that supports the first and second reflecting mirrors 30, 40, the housing 50 can be manufactured without difficulty.

[0093] Furthermore, the first housing 52 is formed with mounting portions 52h, 52j for mounting the first and second shaft portions 44A, 44B, and the second housing 54 is formed with abutment portions 54c, 54d for abutting against the first and second shaft portions 44A, 44B mounted on the mounting portions 52h, 52j to position the second reflecting mirror 40, thereby achieving the following advantageous effects.

[0094] In other words, when the second housing 54 is assembled to the first housing 52, the abutment portion 54c abuts against the first shaft portion 44A of the second reflecting mirror 40, and the abutment portion 54d abuts against the second shaft portion 44B (the base end portion 46a of the lever member 46 fixed thereto) of the second reflecting mirror 40, thereby enabling the second reflecting mirror 40 to be positioned in the up-down and front-to-back directions (i.e., directions perpendicular to the axis Ax) without hindering the rotation of the second reflecting mirror 40.

[0095] Therefore, it is possible to adjust the orientation of the second reflecting mirror 40 without the need to provide a new bracket or the like to rotatably support the second reflecting mirror 40, thereby making it possible to project the display image PIC at the appropriate position on the front window 102.

[0096] Moreover, this can be achieved by a simple operation of placing the second reflecting mirror 40 on the first housing 52 from above and assembling the second housing 54.

[0097] Thus, according to this embodiment, in the image projection device 10 configured to project the display image PIC on the front window 102 as an image display unit, the display image PIC can be projected at an appropriate position with an inexpensive configuration.

[0098] In addition, in this embodiment, a lever member 46 extending in a direction intersecting the axis Ax is fixed to the second shaft portion 44B of the second reflecting mirror 40, and this lever member 46 is connected to an actuator 48 for rotating the second reflecting mirror 40 around the axis Ax, so that it is possible to rotate the second reflecting mirror 40 with the minimum number of necessary parts.

[0099] Moreover, in this embodiment, a mounting portion 52h for mounting the first axis portion 44A of the second reflecting mirror 40 is formed on the inner surface of the peripheral wall portion 52c of the first housing 52, and a mounting portion 52i (second mounting portion) for mounting the lever member 46 is formed on the inner surface opposite the peripheral wall portion 52c of the first housing 52, so that sufficient support rigidity for the second reflecting mirror 40 can be ensured.

[0100] In this embodiment, the mounting portion 52j for mounting the second shaft portion 44B of the second reflecting mirror 40 is formed at a position closer to the first shaft portion 44A than the lever member 46, so that the lever member 46 is supported on both the left and right sides by the first housing 52, thereby enabling the second reflecting mirror 40 to rotate stably.

[0101] Furthermore, in this embodiment, the abutment portions 54c, 54d of the second housing 54 are formed as ribs having arc-shaped recesses, which allows the second reflecting mirror 40 to rotate stably, making it easy to adjust the orientation of the second reflecting mirror 40.

[0102] In the above embodiment, the configuration of each mounting portion 52h, 52j, 152h and each abutment portion 54c, 54d has been described as having a semicircular cross-sectional shape in the portions that abut against the first and second shaft portions 44A, 44B, but it is also possible to adopt a trapezoidal cross-sectional shape instead of a semicircular cross-sectional shape, and it is also possible to configure either each mounting portion 52h, 52j, 152h or each abutment portion 54c, 54d to be formed in a flat shape.

[0103] In the above embodiment, the reflective surfaces 30a, 40a of the first and second reflecting mirrors 30, 40 have been described as having a horizontally long rectangular outer shape, but they may also have other outer shapes.

[0104] In the above embodiment, the surface shape of the reflecting surface 30a of the first reflecting mirror 30 is described as being a saddle-shaped curved surface, and the surface shape of the reflecting surface 40a of the second reflecting mirror 40 is described as being a concave curved surface, but it is also possible to use a configuration with other surface shapes.

[0105] In the above embodiment, the image generating unit 20 is described as being positioned at the center position in the left-right direction of the reflecting surfaces 130a, 40a of the first and second reflecting mirrors 130, 40, but it is also possible to configure it to be positioned at a position shifted left-right from that center position.

[0106] In the above embodiment, the configuration is described as including first and second reflecting mirrors 30, 40, but it is also possible to have a configuration with a single reflecting mirror, and even when such a configuration is adopted, it is possible to obtain approximately the same effects as in the above embodiment.

[0107] In the above embodiment, the image display unit is described as being configured by the front window 102, but it is also possible to configure the image display unit by a translucent plate or the like arranged on the inside of the front window 102 inside the vehicle compartment.

[0108] 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.

[0109] Next, a modification of the above embodiment will be described.

[0110] FIG. 10 is a diagram similar to FIG. 4, showing an image projection device 110 according to this modified example.

[0111] As shown in FIG. 10, the basic configuration of the image projection device 110 according to this modified example is the same as that of the above embodiment, but the support structure of the second reflecting mirror 40 and the configuration of the actuator 170 for rotating the second reflecting mirror 40 are different from those of the above embodiment, and as a result, the configuration of the first housing 152 is partially different from that of the above embodiment.

[0112] That is, in this modified example, the first shaft portion 44A of the second reflecting mirror 40 is placed on a mounting portion 152h formed on the peripheral wall portion 152c of the first housing 152, but the second shaft portion 44B is directly connected to the output shaft 170a of the actuator 170.

[0113] The actuator 170 is fixed at attachment portions 170b formed at two locations by fastening screws 172 to the bottom wall portion 152b of the first housing 152. Therefore, the first housing 152 of this modification does not have the mounting portions 52i, 52j and the protrusion 52k formed on the first housing 52 of the above embodiment.

[0114] Also in this modified example, the second housing (not shown) has an abutment portion (i.e., an abutment portion similar to abutment portion 54c in the above embodiment) formed thereon to abut against the first shaft portion 44A placed on the mounting portion 152h of the first housing 152 to position the second reflecting mirror 40, similar to the second housing 54 in the above embodiment, but does not have an abutment portion corresponding to abutment portion 54d in the above embodiment.

[0115] Even when the configuration of this modified example is adopted, the second reflecting mirror 40 can be rotated by driving the actuator 148, thereby adjusting its orientation.

[0116] Moreover, this can be achieved while simplifying the configuration of the first housing 152 and the like.

[0117] 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.

[0118] Furthermore, the present invention is not limited to the configurations described in the above embodiment and its modifications, and various other modified configurations can be adopted. [Explanation of symbols]

[0119] 2 Driver 10, 110 Image irradiation device 12 Interior Space 20 Image Generation Unit 22 LCD panel 30 1st reflector 30a, 40a reflective surface 32 Flange 32A Side wall part 32B Staircase 32B1 Upper plane part 32B1a Pin insertion hole 32B2 Lower plane part 32B2a Screw insertion hole 34, 172 screws 40 Second reflector 42 Bracket 44A First shaft 44B Second shaft 46 Lever member 46a Proximal end 46b Tip 46c Tab 48, 170 Actuator 48a, 170a output shaft 50 Housing 52, 152 First Housing 52a Top opening 52b, 152b Lower wall part 52c, 152c peripheral wall part 52d Unit mounting part 52e, 54a opening 52f Columnar projection 52f1 Slope 52g pin 52h, 52j, 152h Placement area 52i Placement section (second placement section) 52k clamping part 52m engagement hole 54 Second Housing 54b Outer flange 54c, 54d Contact part 54e Light shielding piece 54e1 Notch 54th floor Lance 60 Translucent cover 100 vehicles 102 Front window (image display area) 102A Display area 104 Steering Wheel 170b Mounting part Ax axis PIC display image R optical path S Sunlight

Claims

1. In an image projection device configured to project a display image on an image display unit, the display device includes an image generating unit that generates the display image, a reflecting mirror that reflects light emitted from the image generating unit toward the image display unit, and a housing that accommodates the reflecting mirror, The housing is configured by assembling a first housing and a second housing, a shaft portion extending in a direction away from the reflecting surface is formed at a side end portion of the reflecting surface of the reflecting mirror, a mounting portion for mounting the shaft portion is formed on the first housing, an abutment portion formed on the second housing for abutting against the shaft portion placed on the placement portion to position the reflecting mirror;

2. 2. The image projection device according to claim 1, wherein the mounting portion is formed on an inner surface of a peripheral wall portion of the first housing.

3. 3. The image projection device according to claim 1, wherein the contact portion is formed as a rib having an arc-shaped recess.

4. The shaft portion includes first and second shaft portions arranged on the same axis at both end portions of the reflecting surface, A lever member extending in a direction intersecting the axis is fixed to the second shaft portion, 4. The image projection device according to claim 1, wherein the lever member is connected to an actuator for rotating the reflecting mirror about the axis.

5. a second mounting portion for mounting the lever member is formed on an inner surface of the peripheral wall portion of the first housing, 5. The image projection device according to claim 4, wherein the placement portion for placing the second shaft portion is formed at a position closer to the first shaft portion than the lever member.

Images