Image irradiation device

Abstract

To make it possible to increase position accuracy of a reflection mirror without making assembly work of a positioning member troublesome in an image irradiation device configured to irradiate an image display part with light emitted from an image generating unit via the reflection mirror.SOLUTION: In an image irradiation device, a positioning member 80 for positioning first and second shaft parts 44A, 44B of a second reflection mirror 40 mounted on mounting parts 52h, 52j in a vertical direction are fitted to a first housing 52. In so doing, the positioning member 80 is composed of a plate spring provided with a substrate part 82 and a lever part 84, and the first and second shaft parts 44A, 44B are elastically pressed from above in the lever part 84 in the state where the positioning member is locked by the first housing 52 in the substrate part 82. Thus, assembly work of the first housing 52 is possible without requiring screw fastening and the like.SELECTED DRAWING: Figure 4

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 translucent 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 including an image generating unit that generates an image for display, a reflecting mirror that reflects the light emitted from the image generating unit toward an image display section, and a housing that contains the reflecting mirror.

[0004] The image projection device described in "Patent Document 1" has a configuration in which a reflecting mirror is supported rotatably about an axis extending in the left-right direction with respect to a housing. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 110580 Summary of the Invention [Problem to be solved by the invention]

[0006] In such an image projection device, it is necessary to improve the positional accuracy of the reflecting mirror in order to accurately project a display image onto the image display section.

[0007] To achieve this, it is necessary to form a shaft portion extending in the axial direction at the side end of the reflector, form a mounting portion on the housing for mounting the shaft portion, and attach a positioning member to the housing for positioning the shaft portion of the reflector in the up-down direction. In this case, if the positioning member is fixed to the housing by screws or the like, the assembly work will be time-consuming.

[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 light emitted from an image generating unit onto an image display unit via a reflecting mirror, which can improve the positional accuracy of the reflecting mirror while eliminating the need for laborious assembly work of the positioning member. [Means for solving the problem]

[0010] The present invention is intended to achieve the above object by providing an improved structure for the positioning 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, the display device includes an image generating unit that generates an image for display, 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 reflecting mirror is supported rotatably about an axis extending in the left-right direction relative to the housing, A shaft portion extending in the axial direction is formed at a side end portion of the reflecting mirror, The housing is formed with a mounting portion for mounting the shaft portion, a positioning member for positioning the shaft portion in a vertical direction is attached to the housing, The positioning member is formed of a leaf spring having a base portion and a lever portion, The positioning member is characterized in that, with the base portion engaged with the housing, the lever portion is configured to elastically press the shaft portion from above.

[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 terms indicating directionality such as the above "left-right direction" and the above "up-down direction" are intended to conveniently indicate the directionality of the image projection device alone when the image projection device is placed with the direction in which the axis extends set as the "left-right direction", and are unrelated to the directionality when the image projection device is actually used (for example, the directionality when mounted on a vehicle).

[0014] 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 arranged on the front window of the vehicle or on the inside of the passenger compartment can be used.

[0015] The "reflecting mirror" is not particularly limited in terms of the specific shape of its reflecting surface, so long as it is configured to reflect the light emitted from the image generating unit toward the image display section.

[0016] The above-mentioned "positioning member" is composed of a leaf spring having a base portion and a lever portion, and as long as it is configured so that, when the base portion is engaged with the housing, the lever portion elastically presses the shaft portion of the reflector from above, there is no particular limitation on its specific configuration. Effect of the Invention

[0017] The image projection device of the present invention is configured so that a reflector for reflecting light emitted from an image generating unit toward an image display section is supported on a housing that contains it so as to be rotatable about an axis extending in the left-right direction. An axis extending in the axial direction is formed on the side end of the reflector, and a mounting section for placing the axis is formed on the housing. Furthermore, a positioning member is attached to the housing for positioning the axis in the up-down direction, so that the positional accuracy of the reflector can be improved, thereby enabling the display image to be accurately projected on the image display section.

[0018] In this case, the positioning member is composed of a leaf spring having a base portion and a lever portion, and is configured so that with the base portion engaged with the housing, the lever portion elastically presses the shaft portion from above. Therefore, assembly work to the housing can be performed without the need for work such as screw tightening, thereby making the assembly work less time-consuming.

[0019] Thus, according to the present invention, in an image projection device configured to project light emitted from an image generating unit onto an image display unit via a reflecting mirror, the positional accuracy of the reflecting mirror can be improved while eliminating the need for laborious assembly work of the positioning member.

[0020] In the above configuration, if the base portion of the positioning member is further configured to have a horizontal surface portion extending horizontally and a pair of front and rear vertical surface portions extending vertically downward from the front and rear end positions of the horizontal surface portion, an opening portion extending in the front and rear direction is formed in the horizontal surface portion, and the lever portion of the positioning member is configured to extend from the front or rear end position of the opening into the opening in a downwardly convex curved state, it becomes easy to elastically press the shaft portion from above, and this makes it easy to accurately position the shaft portion of the reflector relative to the housing.

[0021] In addition, terms indicating directionality such as the above-mentioned "horizontal direction" and "vertically downward" are used for the purpose of conveniently indicating the directionality when the image projection device is arranged with the direction in which the axis extends set as the "left-right direction" as described above, and are unrelated to the directionality when the image projection device is actually used. For example, when the image projection device is mounted on a vehicle or the like, the above-mentioned "horizontal surface portion" may be arranged to extend in the above-mentioned "horizontal direction" or may be arranged to extend in a direction inclined relative to the horizontal direction.

[0022] When such a configuration is adopted, if a second lever portion extending downward is formed at the middle position in the fore-aft direction on the horizontal surface portion, and this second lever portion is configured to abut against the tip surface of the shaft portion of the reflector and elastically press it in the axial direction, it becomes easy to position the shaft portion of the reflector relative to the housing not only in the up-down direction but also in the axial direction.

[0023] Furthermore, the base portion of the positioning member is configured such that a second opening is formed in each of a pair of front and rear vertical surface portions, and locking piece portions are formed extending from their lower ends toward inside the second opening, and the pair of front and rear locking piece portions are formed so as to extend at an angle away from each other in the vertical upward direction, and further, the locking piece portions are locked to the housing, thereby further improving the positional accuracy of the reflector.

[0024] In this case, by configuring the housing so that insertion holes for inserting a pair of front and rear vertical surface portions are formed on both the front and rear sides of the mounting portion, and by configuring the housing so that locking portions for locking the positioning member by abutting the upper edges of the pair of front and rear locking piece portions are formed in the vicinity of the pair of front and rear insertion holes, the positioning member can be reliably locked to the housing. [Brief description of the drawings]

[0025] [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] FIG. 2 is a plan view showing the image projection device with the second housing removed. [Diagram 5] Cross-sectional view of line VV in Figure 4 [Figure 6] Cross section of line VI-VI in Figure 5 [Figure 7] Cross-sectional view of line VII-VII in Figure 6 [Figure 8] Cross-sectional view of line VIII-VIII in Figure 6 [Figure 9] FIG. 2 is a perspective view showing a positioning member of the image projection device alone; [Figure 10] FIG. 6 is a view similar to FIG. 5, showing a modification of the above embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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 .

[0034] As shown in FIG. 1, the image projection device 10 includes an image generation unit 20 that generates a display image that is the basis for the display image PIC, first and second reflectors 30, 40 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.

[0035] The image generating unit 20 and the first and second reflectors 30, 40 are supported in a housing 50 (which will be described below).

[0036] The housing 50 is configured such that a second housing 54 is assembled to a first housing 52 formed to open upward.

[0037] 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 taken along line VV in Fig. 4.

[0038] As shown in FIGS. 3 to 5, 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 in contact with the 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 for transmitting the reflected light from the second reflecting mirror 40 toward the image display unit 102A.

[0040] The light-transmitting cover 60 is made of a colorless and transparent resin panel. The light-transmitting cover 60 is arranged 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 ensures dustproofness of the internal space 12 of the housing 50 while allowing the reflected light from the second reflecting mirror 40 to enter the image display unit 102A.

[0041] As shown in FIGS. 4 and 5, the first and second reflecting mirrors 30, 40 have reflective surfaces 30a, 40a that have bilaterally symmetrical shapes, and the image generating unit 20 is disposed at the center in the bilateral direction.

[0042] The image generating unit 20 includes a liquid crystal panel 22 having a rectangular outer shape, and is disposed so that the liquid crystal panel 22 faces the internal space 12 of the housing 50. Specifically, the image generating unit 20 is supported by the lower wall portion 52b of the first housing 52 with the liquid crystal panel 22 disposed so that the longitudinal direction of the liquid crystal panel 22 extends in the left-right direction (i.e., the vehicle width direction) and with the liquid crystal panel 22 facing diagonally upward and rearward.

[0043] The image generating unit 20 is configured to generate a display image (that is, an image that is the source of the display image PIC) on the liquid crystal panel 22 by illuminating the liquid crystal panel 22 with a backlight from the rear side thereof.

[0044] 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 the unit mounting portion 52d.

[0045] 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 portion 52e of the unit mounting portion 52d.

[0046] 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.

[0047] The first reflecting mirror 30 is configured as a saddle-shaped reflecting mirror in which the surface shape of the reflecting surface 30a is configured as a saddle-shaped curved surface. The reflecting surface 30a of the first reflecting mirror 30 has a substantially rectangular outer shape extending in the left-right direction when viewed from the front of the vehicle. Specifically, the horizontal cross-sectional shape of the reflecting surface 30a is configured as a convex curve, and the vertical cross-sectional shape is configured as a concave curve.

[0048] The first reflecting mirror 30 has flanges 32 formed on both left and right end portions of its reflecting surface 30a, and is fixed to the first housing 52 at the pair of left and right flanges 32.

[0049] Specifically, each flange portion 32 includes a side wall portion 32A formed so as to extend rearward from a side end portion of the reflecting surface 30a along a vertical plane, and a stepped portion 32B formed so as to extend laterally from an outer surface of the side wall portion 32A. The first reflecting mirror 30 is fixed to a pair of left and right columnar protrusions 52f formed on the bottom wall portion 52b of the first housing 52 by means of screws 34 in a state where the pair of left and right stepped portions 32B are positioned and fastened by pins 52g.

[0050] 3 and 4, 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 irradiation light from the image generating unit 20, which is reflected by the first reflecting mirror 30, upward.

[0051] The second reflecting mirror 40 is a concave mirror, and the surface shape of the reflecting surface 40a is a concave surface that is approximately spherical. The reflecting surface 40a of the 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 (i.e., a more horizontally elongated shape) than the reflecting surface 30a of the first reflecting mirror 30.

[0052] In this way, the reflective surface 40a of the second reflecting mirror 40 is formed with a larger aspect ratio than the reflective surface 30a of the first reflecting mirror 30, and is significantly curved in the direction of the image that is desired to be viewed by the driver 2. 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 horizontal direction, which allows the light to efficiently enter the reflective surface 40a of the second reflecting mirror 40.

[0053] The lower wall portion 52b of the first housing 52 is formed at a higher position than the portion where the unit mounting portion 52d is formed and the portion located below the reflective surfaces 30a, 40a of the first and second reflectors 30, 40.

[0054] 3, the second housing 54 is formed with a light-shielding piece 54c that covers the peripheral area of ​​the reflecting surface 30a of the first reflecting mirror 30. The light-shielding piece 54c is formed in a plate shape extending obliquely downward and forward from the rear end edge of the opening 54a in the second housing 54.

[0055] In the image projection device 10, sunlight S entering the vehicle cabin 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 54c.

[0056] As a result, even if a vapor deposition 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, sunlight S that reaches this peripheral area is prevented from being reflected by the vapor deposition film or the like and becoming stray light.

[0057] 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 second reflecting mirror 40 to perform angle adjustment so that the reflected light from the first reflecting mirror 30 is accurately incident on the image display unit 102A of the front windshield 102.

[0058] To achieve this, a pair of left and right vertical flanges 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. The pair of left and right vertical flanges 42 are formed with first and second shafts 44A, 44B extending in both left and right directions (i.e., directions away from the reflecting surface 40a) on the axis Ax.

[0059] The first and second shaft portions 44A, 44B are both formed in a cylindrical shape. In this case, the second shaft portion 44B located on the right side (left side when viewed from the front of the device) is formed with a smaller outer diameter than the first shaft portion 44A located on the left side, but its tip portion is formed with the same outer diameter as the first shaft portion 44A.

[0060] A base end 46a of an arm member 46 extending toward the rear of the device is fixed to the tip surface of the second shaft portion 44B. The base end 46a of the arm member 46 is formed so as to extend in a cylindrical shape coaxially with the second shaft portion 44B, and the outer diameter thereof is set to the same value as the tip of the second shaft portion 44B.

[0061] The tip portion 46b of the arm member 46 is connected to a linear output shaft 72 of an actuator 70 for rotating the second reflecting mirror 40 about the axis Ax.

[0062] The actuator 70 is fixed to the lower wall portion 52 b of the first housing 52 on the lower side thereof, and its linear output shaft 72 is formed so as to extend upward into the internal space 12 of the housing 50 .

[0063] A pair of left and right mounting portions 52h, 52j are formed in a portion located directly below the axis Ax on the bottom wall portion 52b of the first housing 52. The second reflecting mirror 40 is mounted on the mounting portion 52h at its first shaft portion 44A, and is mounted on the mounting portion 52j at its base end portion 46a of the arm member 46 fixed to the second shaft portion 44B.

[0064] The pair of left and right mounting portions 52h, 52j are formed to extend in the direction of the axis Ax from the inner surface of the peripheral wall portion 52c of the first housing 52 in the shape of a semi-cylindrical surface with an inner diameter approximately equal to the outer diameter of the first shaft portion 44A and the base end portion 46a of the arm member 46, and their upper ends are formed into an approximately V-shaped inclined surface when viewed from the side (see Figure 6).

[0065] The first shaft portion 44A and the base end portion 46a of the arm member 46 are positioned in the vertical direction by a pair of left and right positioning members 80 attached to the first housing 52 while placed on a pair of left and right mounting portions 52h, 52j.

[0066] The pair of left and right positioning members 80 are both formed of leaf springs having the same shape. Therefore, in the following, a specific configuration of the positioning member 80 disposed on the right placement portion 52j will be described.

[0067] Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 5. Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6, and Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 6. Furthermore, Fig. 9 is a perspective view showing the positioning member 80 alone.

[0068] 6 to 9, the positioning member 80 is made up of a leaf spring including a base portion 82 and a lever portion 84. The positioning member 80 is configured such that, with the base portion 82 engaged with the first housing 52, the lever portion 84 elastically presses the base end portion 46a of the arm member 46 from above.

[0069] The base portion 82 includes a horizontal surface portion 82A extending horizontally, and a pair of front and rear vertical surface portions 82B extending vertically downward from the front and rear end positions of the horizontal surface portion 82A.

[0070] An opening 82Aa extending in the front-rear direction is formed in the horizontal surface portion 82A. The opening 82Aa has a generally rectangular opening shape extending in the front-rear direction in a plan view.

[0071] The lever portion 84 is formed so as to extend from the rear end position of the opening 82Aa toward inside the opening 82Aa. The lever portion 84 has a rectangular outer shape extending in the front-rear direction in a plan view, and is formed so as to extend toward the inside of the opening 82Aa in a downwardly convex curved state.

[0072] A second lever portion 86 extending downward is formed on the right side surface of the horizontal surface portion 82A at a central position in the front-rear direction. This second lever portion 86 protrudes rightward from the right edge of the horizontal surface portion 82A and then curves concavely leftward, thereby forming a generally M-shape facing sideways when viewed from the front of the device. As shown in Fig. 7, this second lever portion 86 is configured to come into contact with a tip surface 46a1 of the base end portion 46a of the arm member 46, thereby elastically pressing the base end portion 46a leftward (i.e., elastically pressing the second reflecting mirror 40 in the direction of the axis Ax).

[0073] Each of the pair of front and rear vertical surface portions 82B has a second opening 82Ba which is elongated and approximately rectangular in shape, and a vertically elongated rectangular locking piece portion 88 which extends from the lower end position of the second opening 82Ba toward inside the second opening 82Ba is formed.

[0074] The pair of front and rear locking pieces 88 are formed to extend at an angle in a direction away from each other with respect to the vertically upward direction. The positioning member 80 is locked to the first housing 52 by the pair of front and rear locking pieces 88. The specific locking structure is as follows.

[0075] That is, the first housing 52 has a lower wall portion 52b, and a portion located on both front and rear sides of the mounting portion 52j is configured as an upper flat portion 52k extending along a horizontal plane above the axis Ax. The upper flat portion 52k is formed so that its upper surface is at substantially the same height as the upper end position of the outer circumferential surface of the base end portion 46a of the arm member 46 mounted on the mounting portion 52j. A pair of front and rear insertion holes 52m for inserting the pair of front and rear vertical surface portions 82B are formed in the front and rear portions of the mounting portion 52j in the upper flat portion 52k. Furthermore, the lower surface of the portion near the pair of front and rear insertion holes 52m in the upper flat portion 52k is configured as a pair of front and rear locking portions 52n for locking the positioning member 80 by abutting the upper end edges of the pair of front and rear locking pieces 88.

[0076] The first housing 52 is formed with a pair of front and rear vertical ribs 52p extending downward from the upper flat surface portion 52k on both the front and rear sides of the pair of front and rear locking portions 52n. These pair of front and rear vertical ribs 52p are integrally formed with the peripheral wall portion 52c of the first housing 52 on the right side of the mounting portion 52j. The formation of such a pair of front and rear vertical ribs 52p ensures sufficient rigidity around the mounting portion 52j of the first housing 52.

[0077] As shown in Figures 4 and 5, the positioning structure for the first shaft portion 44A placed on the left-side mounting portion 52h has a configuration substantially similar to the positioning structure for the base end portion 46a of the arm member 46 placed on the right-side mounting portion 52j.

[0078] That is, the first housing 52 has a lower wall portion 52b, and the portions located on both the front and rear sides of the mounting portion 52h are configured as upper flat portions 52k extending along a horizontal plane above the axis Ax, and a pair of front and rear insertion holes 52m are formed in both the front and rear portions of the mounting portion 52j.

[0079] Also in this left-side mounting portion 52h, the first shaft portion 44A mounted thereon is positioned relative to the first housing 52 by a positioning member 80, but this positioning member 80 is arranged in a state in which the positioning member 80 arranged on the right-side mounting portion 52j is oriented in an inverted manner.

[0080] By configuring the positioning member 80 in this manner, the second lever portion 86 is brought into contact with the tip surface of the first shaft portion 44A placed on the mounting portion 52h, thereby elastically pressing the first shaft portion 44A in the rightward direction.

[0081] Next, the operation of this embodiment will be described.

[0082] In the image projection device 10 according to this embodiment, the second reflecting mirror 40 for reflecting the light emitted from the image generating unit 20 toward the image display section 102A is supported rotatably around an axis Ax extending in the left-right direction relative to the first housing 52 of the housing 50 that accommodates the second reflecting mirror 40. The side end of the second reflecting mirror 40 is formed with first and second shafts 44A, 44B extending in the direction of the axis Ax. The first housing 52 is formed with mounting portions 52h, 52j for mounting the first and second shafts 44A, 44B (more precisely, the first shaft 44A and the base end 46a of the arm member 46). Furthermore, the first housing 52 is fitted with a positioning member 80 for positioning the first and second shafts 44A, 44B in the up-down direction. This improves the positional accuracy of the second reflecting mirror 40, thereby enabling the display image PIC to be accurately displayed on the image display section 102A.

[0083] In this case, the positioning member 80 is composed of a leaf spring having a base portion 82 and a lever portion 84, and is configured so that when the base portion 82 is engaged with the first housing 52, the lever portion 84 elastically presses the first and second shaft portions 44A, 44B from above. Therefore, assembly work to the first housing 52 can be performed without the need for work such as screw tightening, thereby making the assembly work less tedious.

[0084] Thus, according to this embodiment, in an image projection device 10 configured to project light emitted from an image generating unit 20 onto an image display section 102A via a first and second reflecting mirror 30, 40, the positional accuracy of the second reflecting mirror 40 can be improved while eliminating the need for laborious assembly work of the positioning member 80.

[0085] In this case, the positioning member 80 of this embodiment has a base portion 82 with a horizontal surface portion 82A extending horizontally and a pair of front and rear vertical surface portions 82B, an opening portion 82Aa extending in the front-rear direction is formed in the horizontal surface portion 82A, and the lever portion 84 is formed so as to extend from the front end position or the rear end position of the opening portion 82Aa toward the inside of the opening portion 82Aa in a downwardly convex curved state, so that the first and second shaft portions 44A, 44B can be easily elastically pressed from above. This makes it easy to position the first and second shaft portions 44A, 44B of the second reflecting mirror 40 with high accuracy relative to the first housing 52.

[0086] Furthermore, the positioning member 80 of this embodiment is configured to have a second lever portion 86 extending downward formed at the middle position in the fore-and-aft direction on the horizontal surface portion 82A, and this second lever portion 86 is configured to abut against the tip surfaces of the first and second shaft portions 44A, 44B of the second reflecting mirror 40 and elastically press them in the direction of the axis Ax, making it easy to position the first and second shaft portions 44A, 44B of the second reflecting mirror 40 relative to the first housing 52 not only in the up-and-down direction but also in the direction of the axis Ax.

[0087] Furthermore, the base portion 82 of the positioning member 80 has a second opening 82Ba formed in each of a pair of front and rear vertical surface portions 82B, and is configured so that a locking piece portion 88 is formed extending from the lower end position of the second opening 82Ba toward inside the second opening 82Ba.The pair of front and rear locking piece portions 88 are engaged with the first housing 52 in a state in which they extend at an angle away from each other in the vertical upward direction, thereby further improving the positional accuracy of the second reflecting mirror 40.

[0088] In this case, insertion holes 52m for inserting a pair of front and rear vertical surface portions 82B are formed on both the front and rear sides of the mounting portions 52h, 52j of the first housing 52, and locking portions 52n for locking the positioning member 80 by abutting the upper edges of the pair of front and rear locking piece portions 88 are formed in the vicinity of the pair of front and rear insertion holes 52m of the first housing 52, thereby ensuring that the positioning member 80 is locked to the first housing 52.

[0089] In the above embodiment, the second shaft portion 44B of the second reflector 40 is described as being placed on the mounting portion 52j of the first housing 52 at the base end 46a of the arm member 46 fixed thereto, but it is also possible to configure the second shaft portion 44B itself to be placed on the mounting portion 52j of the first housing 52.

[0090] In the above embodiment, the image projection device 10 has been described as having first and second reflecting mirrors 30, 40, but it is also possible to configure it with a single reflecting mirror (specifically, only the second reflecting mirror 40), and even when such a configuration is adopted, it is possible to obtain substantially the same effects as in the above embodiment.

[0091] 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.

[0092] 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.

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

[0094] FIG. 10 is a diagram similar to FIG. 5, showing an image projection device 110 according to this modified example.

[0095] As shown in FIG. 10, the basic configuration of this modified example is similar to that of the above embodiment, but the support structure of second reflecting mirror 40 with respect to first housing 52 is partially different from that of the above embodiment.

[0096] That is, this modified example differs from the above embodiment in that second housing 154 of housing 150 has a function for positioning first shaft portion 44A of second reflecting mirror 40 in the up-down direction.

[0097] Specifically, the first shaft portion 44A is placed on the mounting portion 52h of the first housing 52 and is abutted against a downward positioning rib 154d formed on the outer peripheral flange portion 154b of the second housing 154, thereby positioning the first shaft portion 44A in the vertical direction.

[0098] In this modified example, the second shaft portion 44B (more precisely, the base end portion 46a of the arm member 46) placed on the mounting portion 52j of the first housing 52 is positioned in the vertical direction by a positioning member 80 attached to the first housing 52, as in the above embodiment.

[0099] Even when the configuration of this modified example is adopted, substantially the same effects as those of the above embodiment can be obtained.

[0100] Furthermore, by adopting the configuration of this modified example, when the second housing 154 is assembled to the first housing 52, the positioning rib 154d abuts against the first shaft portion 44A, thereby positioning the first shaft portion 44A.

[0101] On the other hand, when the configuration of this modified example is adopted, the positioning accuracy decreases compared to the configuration in the above embodiment in which the positioning of the first shaft portion 44A is performed using the elastic pressing force of the positioning member 80. However, even in this modified example, the positioning of the second reflecting mirror 40 with respect to the base end portion 46a of the arm member 46 that rotates the second reflecting mirror 40 is performed with high accuracy by the positioning member 80, so that it is possible to maintain the positioning accuracy of the second reflecting mirror 40 within a practically acceptable range.

[0102] 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.

[0103] 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]

[0104] 2 Driver 10, 110 Image projection device 12 Interior Space 20 Image Generation Unit 22 Liquid crystal panel 30 1st reflector 30a, 40a reflective surface 32 Flange section 32A Side wall part 32B Staircase 34 Screws 40 Second reflector 42 Vertical flange section 44A First Shaft 44B Second shaft 46 Arm member 46a Proximal end 46b Tip 50, 150 Housing 52 1st Housing 52a Top opening 52b Lower wall part 52c Peripheral wall part 52d Unit mounting part 52e opening 52f Columnar projection 52g pin 52h, 52j Placement area 52k Upper plane part 52m insertion hole 52n Locking part 52p Vertical Rib 54, 154 Second Housing 54a opening 54b, 154b Outer periphery flange 54c Light shielding piece 60 Translucent cover 70 Actuator 72 Linear output shaft 80 Positioning member 82 Base 82A Horizontal part 82Aa opening 82B Vertical surface 82Ba 2nd opening 84 Lever section 86 Second lever part 88 Locking piece 100 vehicles 102 Front window 102A Image display section 104 Steering Wheel 154d Positioning rib Ax axis PIC Image for display 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 an image for display, 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 reflecting mirror is supported rotatably about an axis extending in the left-right direction relative to the housing, A shaft portion extending in the axial direction is formed at a side end portion of the reflecting mirror, The housing is formed with a mounting portion for mounting the shaft portion, a positioning member for positioning the shaft portion in a vertical direction is attached to the housing, The positioning member is formed of a leaf spring having a base portion and a lever portion, The image projection device, wherein the positioning member is configured such that the lever portion elastically presses the shaft portion from above in a state in which the base portion is engaged with the housing.

2. the base portion includes a horizontal surface portion extending horizontally, and a pair of front and rear vertical surface portions extending vertically downward from a front end position and a rear end position of the horizontal surface portion, An opening extending in a front-rear direction is formed in the horizontal surface portion, 2. The image projection device according to claim 1, wherein the lever portion is formed so as to extend from a front end position or a rear end position of the opening toward the inside of the opening in a downwardly convex curved state.

3. a second lever portion extending downward is formed at a middle position in the front-rear direction of the horizontal surface portion, 3. The image projection device according to claim 2, wherein the second lever portion is configured to come into contact with a tip surface of the shaft portion and elastically press the shaft portion in the axial direction.

4. A second opening is formed in each of the pair of front and rear vertical surface portions, A locking piece portion is formed on each of the pair of front and rear vertical surface portions, the locking piece portion extending from a lower end position of the second opening toward inside the second opening, The pair of front and rear locking pieces are formed to extend inclined directions away from each other with respect to the vertical direction, 4. The image projection device according to claim 2, wherein the positioning member is engaged with the housing at the pair of front and rear engaging pieces.

5. insertion holes for inserting the pair of front and rear vertical surface portions therethrough are formed at both front and rear portions of the mounting portion of the housing, The image projection device according to claim 4, characterized in that a locking portion for locking the positioning member by abutting the upper edges of the pair of front and rear locking pieces is formed in the vicinity of the pair of front and rear insertion holes in the housing.

Images