Image irradiation device

Abstract

In an image illumination device configured to illuminate an image display unit with light emitted from an image generation unit via a reflector, the positional accuracy of the reflector is improved. [Solution] The second reflector 40, which reflects light emitted from the image generation unit toward the image display unit, is provided with a shaft member 60 extending in the left-right direction at its side end, and an outer peripheral flange portion 66 is formed on the outer peripheral surface of the tip of this shaft member 60. On the other hand, a bracket 70 having a flange contact portion 72 that abuts against the outer peripheral flange portion 66 from the base end side of the shaft member 60 is attached to the first housing 52. A pressing member 80 is positioned between the reflector connecting portion 64 of the shaft member 60 and the bracket 70 to elastically press the flange contact portion 72 toward the outer peripheral flange portion 66. This makes it possible to reliably hold the second reflector 40 in a positional state in the left-right direction and improves its positional accuracy.

Description

Technical Field

[0001] The present invention relates to an image irradiation device configured to project a display image onto an image display unit.

Background Art

[0002] Conventionally, as an in-vehicle image irradiation device, there is known one configured to project a display image onto an image display unit such as a front window (i.e., a windshield) or a light-transmitting plate disposed on the vehicle interior side thereof while being disposed inside the vehicle.

[0003] In "Patent Document 1", there is described such an image irradiation device including an image generation unit that generates a display image, a reflecting mirror that reflects the emitted light from this image generation unit toward the image display unit, and a housing that houses this reflecting mirror.

[0004] The image irradiation device described in this "Patent Document 1" has a configuration in which the reflecting mirror is supported by the housing so as to be rotatable about an axis extending in a required direction. At that time, a shaft member extending in the required direction is provided at a side end portion of the reflecting mirror, and the housing has a configuration in which a first housing and a second housing are assembled. A bearing portion for supporting the shaft member of the reflecting mirror is formed in the first housing, and a contact portion that contacts the outer peripheral surface of the shaft member supported by this bearing portion is formed in the second housing.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As described in "Patent Document 1" above, by providing a configuration in which the reflector is supported so as to be rotatable around an axis extending in the required direction, it becomes possible to adjust the height position of the displayed image according to the driver's height, preferences, etc.

[0007] Furthermore, if the image irradiation device described in "Patent Document 1" above is configured such that the contact portion formed on the second housing contacts the outer circumferential surface of the shaft member supported by the bearing portion of the first housing, it becomes possible to position the shaft member of the reflector with respect to a direction intersecting the required direction.

[0008] However, considering the effects of vehicle vibration and other factors, it is desirable to improve the positional accuracy of the reflector by securely holding it in a predetermined position, from the standpoint of accurately displaying the image on the image display unit.

[0009] It should be noted that these same issues can also arise in image projection devices other than those used in vehicles.

[0010] The present invention has been made in view of these circumstances, and aims to provide an image illumination device that can improve the positional accuracy of the reflecting mirror in an image illumination device configured to illuminate an image display unit with light emitted from an image generation unit via a reflecting mirror. [Means for solving the problem]

[0011] The present invention aims to achieve the above objective by modifying the support structure of the reflecting mirror.

[0012] In other words, the image irradiation device according to the present invention is In an image projection device configured to display an image on an image display unit, The system comprises an image generation unit that generates the above-mentioned display image, a reflector that reflects the light emitted from the image generation unit toward the image display unit, and a housing that accommodates the reflector. The above-mentioned reflector is supported in the housing so as to be rotatable about an axis extending in the required direction. A shaft member extending in the required direction is provided at the side end of the above-mentioned reflecting mirror. An outer peripheral flange portion is formed on the outer peripheral surface of the shaft member, extending in the circumferential direction with respect to the axis. A bracket having a flange contact portion formed to abut against the outer peripheral flange portion from the base end side of the shaft member is attached to the housing. The present invention is characterized in that a pressing member is positioned between the side end of the reflector and the bracket, which elastically presses the flange contact portion toward the outer peripheral flange portion.

[0013] The above-mentioned "image projection device" is configured to project an image for display onto an image display unit, and its specific applications are not particularly limited; for example, it can be used in applications such as in-vehicle head-up displays.

[0014] The specific direction referred to as the "required direction" above is not particularly limited; for example, the horizontal direction can be used.

[0015] The "image display unit" described above is not limited in its specific configuration as long as it is configured to display an image; for example, a translucent panel placed on the front windshield of a vehicle or on the interior side of the vehicle can be used.

[0016] The "reflector" described above is configured to reflect light emitted from the image generation unit toward the image display unit, but its specific reflective surface shape and other characteristics are not particularly limited.

[0017] The "shaft member" mentioned above may be composed of a separate component from the reflector, or it may be composed as part of the reflector.

[0018] The above-mentioned "outer peripheral flange portion" may be formed to extend in the circumferential direction around the above-mentioned axis, and may be formed over the entire circumference or may be formed in a state where a part in the circumferential direction is missing.

[0019] The specific shape of the above-mentioned "flange contact portion" is not particularly limited as long as it is formed to contact the outer peripheral flange portion from the base end side of the shaft member.

[0020] The specific configuration of the above-mentioned "pressing member" is not particularly limited as long as it is configured to elastically press the flange contact portion toward the outer peripheral flange portion while being disposed between the side end portion of the reflecting mirror and the bracket. For example, a compression spring, rubber, or the like can be adopted.

Advantages of the Invention

[0021] In the image irradiation device according to the present invention, a reflecting mirror for reflecting the emitted light from the image generation unit toward the image display unit is supported so as to be rotatable around an axis extending in a required direction with respect to a housing that houses the reflecting mirror. Therefore, the height position of the display image can be adjusted according to the height and preferences of the driver.

[0022] Furthermore, a shaft member extending in the above-mentioned required direction is provided at the side end portion of the reflecting mirror, and an outer peripheral flange portion is formed on the outer peripheral surface of this shaft member. On the other hand, a bracket having a flange contact portion formed to contact the outer peripheral flange portion from the base end side of the shaft member is attached to the housing. Further, a pressing member for elastically pressing the flange contact portion toward the outer peripheral flange portion is disposed between the side end portion of the reflecting mirror and the bracket. Therefore, the following operational effects can be obtained.

[0023] That is, in a state where the reflecting mirror is positioned with respect to the above-mentioned required direction by the contact between the flange contact portion and the outer peripheral flange portion, this positioning state can be reliably maintained by the pressing member, and thereby the positional accuracy of the reflecting mirror can be improved.

[0024] According to the invention of the present application, in an image irradiation device configured to irradiate light emitted from an image generation unit to an image display unit through a reflecting mirror, the positional accuracy of the reflecting mirror can be improved.

[0025] In the above configuration, further, if the outer peripheral flange portion has a conical surface shape centered on the above axis and the flange contact portion is formed to have a conical surface shape in surface contact with the outer peripheral flange portion, the shaft member can be held in a centered state, and thereby the positional accuracy of the reflecting mirror can be further improved.

[0026] In the above configuration, further, if the pressing member is constituted by a coil spring attached to the shaft member, and one end portion thereof is locked to the reflecting mirror and the other end portion is locked to the bracket, the reflecting mirror can be biased in one direction around the above axis, and thereby the reflecting mirror can be accurately positioned with respect to the direction around the above axis.

[0027] In the above configuration, further, as the configuration of the outer peripheral flange portion, a part in the circumferential direction is formed in a state of being missing, and as the configuration of the bracket, an insertion hole for inserting the shaft member in the above axial direction is formed. With respect to the outer peripheral flange portion of the shaft member inserted into this insertion hole and rotating around the above axis, if the flange contact portion contacts from the base end portion side of the shaft member, the reflecting mirror can be easily assembled to the bracket.

[0028] At that time, as the configuration of the bracket, if a protrusion is formed to limit the rotatable angle of the reflecting mirror around the above axis within a predetermined angle range by contact with the circumferential end surface portion of the outer peripheral flange portion, it is possible to effectively suppress the accidental dropping of the reflecting mirror from the engaged state due to vehicle vibration or the like.

[0029] In the above configuration, if an actuator for rotating the reflector around the axis is further supported on the bracket, and this actuator is configured to have an output shaft extending in the required direction, and this output shaft is connected to the tip of the shaft member, then the placement of the actuator can be easily facilitated.

[0030] In the above configuration, if a bearing portion for supporting the shaft member is formed in the bracket, and this bearing portion has a U-shaped cross-section with a part of its circumferential direction open, and the flange contact portion contacts the outer circumferential flange portion of the shaft member supported by this bearing portion from the base end side of the shaft member, then the assembly of the reflector to the bracket can be easily performed.

[0031] In the above configuration, if an actuator for rotating the reflector around the axis is further supported on the bracket, and a worm wheel tooth profile with the axis as the rotation center is formed on the outer circumferential surface of the shaft member, and an extension shaft member having a worm tooth profile that meshes with the worm wheel tooth profile is attached to the output shaft of the actuator, the rotation angle of the reflector can be adjusted with high precision.

[0032] In this case, if the bracket is configured to have a support hole for rotatably supporting the tip of the extension shaft member, the extension shaft member can be reliably supported in this support hole, thereby further improving the accuracy of adjusting the rotation angle of the reflector. [Brief explanation of the drawing]

[0033] [Figure 1] Side cross-sectional view showing the image irradiation device according to the first embodiment of the present invention mounted on a vehicle. [Figure 2] View from the direction arrow II in Figure 1 [Figure 3] Detailed view of Part III in Figure 1 [Figure 4] Plan view showing the above image projection device with the second housing removed. [Figure 5] Figure 4: Cross-sectional view along line VV [Figure 6] Detailed view of section VI in Figure 4 [Figure 7] Figure 5, section view along line VII-VII [Figure 8] Detailed view of section VIII in Figure 5 [Figure 9] This is a perspective view showing the main components of the first embodiment as disassembled and viewed from below. [Figure 10] A diagram illustrating the operation of the first embodiment described above. [Figure 11] Figure 4 shows a second embodiment of the present invention. [Figure 12] Detailed view of section XII in Figure 11 [Figure 13] Figure 11 shows a cross-sectional view along line XIII-XIII. [Modes for carrying out the invention]

[0034] Embodiments of the present invention will be described below with reference to the drawings.

[0035] First, a first embodiment of the present invention will be described.

[0036] Figure 1 is a side cross-sectional view showing the image illumination device 10 according to this embodiment mounted on a vehicle 100. Figure 2 is a view taken in the direction of arrow II in Figure 1.

[0037] In Figures 1 and 2, the direction indicated by X is the "forward" direction for the image projection device 10 (and also the "forward" direction for the 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. The same applies to figures other than Figures 1 and 2.

[0038] As shown in Figures 1 and 2, the image projection device 10 according to this embodiment is an in-vehicle head-up display that, when placed inside the vehicle 100, is configured to project a display image PIC as a virtual image onto an image display unit 102A set on the inner surface of the front windshield 102.

[0039] The optical path R shown in Figure 1 is the optical path through which the driver 2 visually perceives the display image PIC projected onto the image display unit 102A by the image projection device 10.

[0040] The image display unit 102A is positioned in the lower area of ​​the front windshield 102 and in front of the steering wheel 104, and is set as a horizontally elongated rectangular area. This allows the driver 2 of the vehicle 100 to easily visually recognize the display image PIC projected onto the image display unit 102A.

[0041] Figure 2 shows a specific example of a display image PIC, where the vehicle speed (50 km / h) is displayed along with a leftward-pointing arrow.

[0042] The image projection device 10 is positioned in front of the steering wheel 104 and near the bottom of the front windshield 102.

[0043] As shown in Figure 1, the image projection device 10 comprises an image generation unit 20 that generates a display image which will be the basis for the display image PIC, first and second reflectors 30 and 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 houses these components, and a light-transmitting cover 56 mounted on the housing 50.

[0044] The image generation unit 20 and the first and second reflectors 30 and 40 are supported by the housing 50 (which will be described later).

[0045] The housing 50 is configured such that the second housing 54 is assembled to the first housing 52, which is formed to open upwards.

[0046] Figure 3 is a detailed view of part III of Figure 1. Figure 4 is a plan view showing the image irradiation device 10 with the second housing 54 removed, and Figure 5 is a cross-sectional view taken along line VV of Figure 4.

[0047] As shown in Figures 3 to 5, the second housing 54 has an outer peripheral flange portion 54b, and is assembled to the first housing 52 with this outer peripheral flange portion 54b in contact with the upper end opening 52a of the first housing 52.

[0048] The first and second housings 52 and 54 are both made of opaque resin molded products. The second housing 54 has an opening 54a formed therein to transmit reflected light from the second reflector 40 toward the image display unit 102A.

[0049] The light-transmitting cover 56 is made of a colorless, transparent resin panel. This light-transmitting cover 56 is positioned to cover the opening 54a of the second housing 54, with a downward curve and a slight upward inclination toward the rear. This light-transmitting cover 56 allows reflected light from the second reflector 40 to enter the image display unit 102A, while ensuring dustproofing of the internal space 12 of the housing 50.

[0050] As shown in Figures 4 and 5, the first and second reflecting mirrors 30 and 40 have symmetrical reflective surfaces 30a and 40a, and the image generation unit 20 is positioned at the center of these mirrors in the left-right direction.

[0051] The image generation unit 20 includes a liquid crystal panel 22 having a rectangular external shape, and this liquid crystal panel 22 is positioned to face the internal space 12 of the housing 50. Specifically, the image generation 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 backward.

[0052] The image generation unit 20 is configured to generate a display image (i.e., the image that will be the basis for the display image PIC) on the liquid crystal panel 22 by illuminating the liquid crystal panel 22 with a backlight from its rear side.

[0053] A unit mounting section 52d for mounting the image generation unit 20 is formed in the lower wall portion 52b of the first housing 52. A rectangular opening 52e, which is slightly larger than the outer shape of the liquid crystal panel 22, is formed in this unit mounting section 52d.

[0054] The image generation unit 20 is fixed to the lower wall portion 52b of the first housing 52 by screws or the like, with the liquid crystal panel 22 positioned so that it fits into the opening 52e of the unit mounting portion 52d.

[0055] The first reflector 30 is positioned diagonally above and behind the image generation unit 20 and is configured to reflect the light emitted from the image generation unit 20 forward.

[0056] The first reflector 30 is configured as a saddle-type reflector, with its reflective surface 30a having a saddle-shaped curved surface. The reflective surface 30a of this first reflector 30 has a roughly rectangular outer shape that extends in the left-right direction when viewed from the front of the vehicle. Specifically, the horizontal cross-sectional shape of this reflective surface 30a is composed of a convex curve, and its vertical cross-sectional shape is composed of a concave curve.

[0057] The first reflector 30 has flange portions 32 formed on both the left and right ends of its reflective surface 30a, and is fixed to the first housing 52 at these left and right pair of flange portions 32.

[0058] Specifically, each flange portion 32 includes a side wall portion 32A formed to extend rearward along a vertical plane from the side end of the reflective surface 30a, and a stepped portion 32B formed to extend laterally from the outer surface of the side wall portion 32A. The first reflector 30 is then fastened and fixed by screws 34 to a pair of left and right columnar projections 52f formed on the lower wall portion 52b of the first housing 52, with the left and right stepped portions 32B positioned by pins 52g.

[0059] As shown in Figures 3 and 4, the second reflector 40 is positioned in front of the first reflector 30. This second reflector 40 is configured to reflect the light emitted from the image generation unit 20, which has been reflected by the first reflector 30, upwards.

[0060] The second reflector 40 is a concave mirror, and the surface shape of its reflective surface 40a is a substantially spherical concave curved surface. The reflective surface 40a of the second reflector 40 has a rectangular outer shape that extends in the left-right direction when viewed from the front of the vehicle. The reflective surface 40a of the second reflector 40 is formed to be larger in size than the reflective surface 30a of the first reflector 30, and is formed to have a larger aspect ratio (i.e., a more horizontally elongated shape) than the reflective surface 30a of the first reflector 30.

[0061] Thus, the reflective surface 40a of the second reflector 40 is curved significantly in the direction of the image that the driver 2 is to see, and is formed with a larger aspect ratio than the reflective surface 30a of the first reflector 30. However, since the first reflector 30 is configured as a saddle-shaped reflector, the reflected light from its reflective surface 30a has a small vertical spread and a large horizontal spread, which allows it to efficiently enter the reflective surface 40a of the second reflector 40.

[0062] The lower wall portion 52b of the first housing 52 is formed at a higher position in the surrounding area 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.

[0063] As shown in Figure 3, the second housing 54 has a light-shielding piece 54c that covers the peripheral area of ​​the reflective surface 30a of the first reflector 30. This light-shielding piece 54c is formed to extend in a plate shape diagonally downward and forward from the rear edge of the opening 54a in the second housing 54.

[0064] In the image illumination device 10, sunlight S that enters the vehicle interior through the front windshield 102 may enter the internal space 12 of the housing 50 through the light-transmitting cover 56. However, the light-shielding action of the light-shielding piece 54c prevents this sunlight S from reaching the peripheral area of ​​the reflective surface 30a of the first reflector 30.

[0065] As shown in Figures 4 and 5, the second reflector 40 is supported by the first housing 52 so as to be rotatable around an axis Ax that extends in the left-right direction near the front of the second reflector 40. This configuration allows the second reflector 40 to be angle-adjusted to accurately direct the reflected light from the first reflector 30 onto the image display unit 102A of the front window 102.

[0066] As shown in Figure 3, this angle adjustment is performed within a relatively small angle range indicated by the dashed and dotted lines under normal use conditions. However, when not in use, the second reflector 40 rotates significantly to the rearward position indicated by the double dotted line, so that even if sunlight S is reflected by the second reflector 40, it does not reach the first reflector 30.

[0067] As shown in Figures 4 and 5, a pair of plate-shaped flange portions 42 are formed on both the left and right ends of the back side of the reflective surface 40a of the second reflector 40, extending forward along the vertical plane. These left and right pair of plate-shaped flange portions 42 extend to a position diagonally downward and forward from the axis Ax, and then extend in a flat shape in both left and right directions (i.e., away from the reflective surface 40a), forming an L-shape overall.

[0068] The second reflector 40 is provided with a pair of left and right axial members 60 that extend in the left-right direction at both ends.

[0069] Figure 6 is a detailed view of section VI of Figure 4, showing the shaft member 60 located on the right side (left side when viewed from the front of the device) and its surrounding structure. Figure 7 is a cross-sectional view taken along line VII-VII of Figure 5, and Figure 8 is a detailed view of section VIII of Figure 5.

[0070] As shown in Figures 6-8, each of the left and right pairs of shaft members 60 includes a cylindrical shaft body portion 62 extending in the left-right direction with respect to the axis Ax, a reflector connecting portion 64 formed at the base end of the shaft body portion 62, and an outer peripheral flange portion 66 formed on the outer peripheral surface of the shaft body portion 62.

[0071] On the other hand, the first housing 52 is fitted with a pair of left and right brackets 70, each having flange contact portions 72 formed to contact the outer peripheral flange portions 66 of the left and right shaft members 60 from the base end side of the shaft members 60.

[0072] Furthermore, pressing members 80 are positioned between the left and right ends of the second reflector 40 and the pair of left and right brackets 70, respectively, to elastically press the flange contact portion 72 toward the outer flange portion 66.

[0073] Furthermore, the right-side bracket 70 supports an actuator 90 for rotating the second reflector 40 around the axis Ax. This actuator 90 has an output shaft 92 that extends to the left along the axis Ax, and this output shaft 92 is connected to the tip of the right-side shaft member 60.

[0074] Since the configurations of the left and right pairs of shaft members 60, brackets 70, and pressing members 80 are the same, the specific configuration of the right shaft member 60, bracket 70, and pressing member 80 will be described below.

[0075] Figure 9 is a perspective view showing the shaft member 60, bracket 70, and pressing member 80 together with the actuator 90, as disassembled and viewed from below.

[0076] As shown in Figure 9, the outer peripheral flange portion 66 of the shaft member 60 is formed to extend circumferentially around the axis Ax at the tip of the shaft body portion 62. In this case, the outer peripheral flange portion 66 is formed with two opposing sections missing with respect to the axis Ax. The surface 66a of the outer peripheral flange portion 66 located on the base end side of the shaft body portion 62 is composed of a conical surface centered on the axis Ax.

[0077] On the other hand, the bracket 70 includes a base portion 70A that extends in the front-rear direction at a position away from the axis Ax, and a vertical wall portion 70B that extends from the inner edge of the base portion 70A (i.e., the side edge on the second reflector 40 side) along a plane perpendicular to the axis Ax.

[0078] The vertical wall portion 70B of the bracket 70 has an insertion hole 70Ba formed therein for inserting the shaft member 60 in the axial direction Ax. This insertion hole 70Ba has an opening shape that is slightly larger than the shaft body portion 62 of the shaft member 60, and two of its circumferential openings have a diameter that is slightly larger than the outer peripheral flange portion 66 of the shaft member 60. In this case, the central angle of the portion of the insertion hole 70Ba that is formed with a large diameter is set to a value that is slightly larger than that of the portion where the outer peripheral flange portion 66 is formed.

[0079] The bracket 70 is configured such that, after the shaft body portion 62 of the shaft member 60 is inserted into its through hole 70Ba, the shaft member 60 rotates by a predetermined angle around the axis Ax, causing the flange contact portion 72 to contact the outer peripheral flange portion 66 of the shaft member 60 from the base end side. The surface 70a of the tip side of the flange contact portion 72 is composed of a conical surface centered on the axis Ax, and its inclination angle is set to the same value as the surface 66a of the outer peripheral flange portion 66 of the shaft member 60. As a result, the shaft member 60 is positioned so that the surface 66a of the outer peripheral flange portion 66 is in surface contact with the surface 70a of the flange contact portion 72, thereby stably supporting the shaft member 60 while centered on the axis Ax.

[0080] The outer surface of the vertical wall portion 70B of the bracket 70 has four projections 76 formed in the circumferential direction. When the second reflector 40 rotates around the axis Ax, the circumferential end faces of the pair of outer peripheral flange portions 66 of the shaft member 60 come into contact with two of the projections 76, thereby limiting the rotatable angle to a predetermined angular range.

[0081] As shown in Figure 6, the bracket 70 is fastened and fixed to the lower wall portion 52b of the first housing 52 by screws 82 at two locations on the front and rear of its base portion 70A. At this time, the bracket 70 is positioned by inserting a pair of front and rear positioning pins 52k formed on the first housing 52 into a pair of front and rear positioning holes 70Aa formed on the base portion 70A of the bracket 70. One of the pair of front and rear positioning holes 70Aa is formed as an elongated hole extending in the front-rear direction.

[0082] The shaft member 60 is connected to the plate-shaped flange portion 42 of the second reflector 40 at a reflector connecting portion 64 formed at its base end. This connection is made by overlapping the reflector connecting portion 64 with the plate-shaped flange portion 42 and tightening screws 84 at two locations.

[0083] The pressing member 80 is composed of a metal compression coil spring attached to the shaft body portion 62 of the shaft member 60, and is positioned in a state of compression deformation in the left-right direction with both ends of the spring in contact with the outer surface of the reflector connecting portion 64 on the shaft member 60 and the inner surface of the bracket 70.

[0084] The shaft member 60 has an engagement hole 60a formed on the tip surface of its shaft body portion 62 for engaging with the output shaft 92 of the actuator 90. The output shaft 92 has a surface shape in which two opposing locations on the cylindrical surface centered on the axis Ax are chamfered into a planar shape, and the engagement hole 60a has an opening shape corresponding to this. As a result, when the output shaft 92 is inserted into the engagement hole 60a and rotates, the shaft member 60 rotates around the axis Ax.

[0085] The actuator 90 is fixed to the bracket 70 by tightening screws 86 onto bosses 74 formed at two locations on the front and rear of the vertical wall portion 70B of the bracket 70.

[0086] Figure 10 shows the process of assembling the shaft member 60 to the bracket 70, where Figures 10(a1) to (a3) ​​are plan views and Figures 10(b1) to (b3) are right side views.

[0087] The assembly process for the shaft member 60 is as follows:

[0088] First, as shown in Figures 10(a1) and (b1), with the pressing member 80 attached to the shaft body portion 62 of the shaft member 60, the shaft body portion 62 is inserted into the insertion hole 70Ba formed in the vertical wall portion 70B of the bracket 70. At this time, the outer peripheral flange portion 66 of the shaft member 60 is aligned with the large diameter portion of the insertion hole 70Ba with respect to the circumferential direction of the axis Ax.

[0089] Next, as shown in Figures 10(a2) and (b2), while compressing and deforming the pressing member 80, the shaft body portion 62 of the shaft member 60 is inserted until its tip protrudes to the opposite side of the insertion hole 70Ba, and then the shaft member 60 is rotated around the axis Ax.

[0090] Subsequently, as shown in Figures 10(a3) and (b3), when the force pressing the shaft member 60 in the direction of the axis Ax is released, the elastic force of the pressing member 80 causes the outer peripheral flange portion 66 of the shaft member 60 to come into contact with the flange contact portion 72 of the bracket 70. At this time, the surface 66a of the outer peripheral flange portion 66 and the surface 72a of the flange contact portion 72 come into surface contact. As a result, the shaft member 60 is centered on the axis Ax, and its assembly to the bracket 70 is completed.

[0091] Once this assembly is complete, the shaft member 60 is able to rotate around the axis Ax relative to the bracket 70, but its maximum rotation angle is limited by contact with two of the four projections 76 formed in the circumferential direction.

[0092] Specifically, the shaft member 60 contacts a pair of projections 76 when rotated relatively small in angle to the rear from the positions shown in Figures 10(a3) and (b3), and contacts another pair of projections 76 when rotated relatively large in angle to the front from the positions shown in Figures 10(a3) and (b3). As a result, as shown in Figure 7, the second reflector 40 can rotate within a relatively small angular range shown by the dashed and dotted lines in normal use, while in non-use state, it is allowed to rotate significantly to the rear to the position shown by the double-dotted line.

[0093] In this embodiment, the second reflector 40 is attached to the first housing 52 by screw fastening the pair of left and right shaft members 60, which are assembled to a pair of left and right brackets 70, at the left and right plate-shaped flange portions 42 of the second reflector 40.

[0094] Next, the operation of this embodiment will be described.

[0095] In this embodiment, the image illumination device 10 has a second reflector 40 (reflector) for reflecting light emitted from the image generation unit 20 toward the image display unit 102A, which is supported in a housing 50 that houses it so as to be rotatable around an axis Ax extending in the left-right direction (required direction). Therefore, the height position of the display image PIC can be adjusted according to the driver's height and preferences.

[0096] Furthermore, in this embodiment, a shaft member 60 extending in the left-right direction is provided at the side end of the second reflector 40, and an outer peripheral flange portion 66 is formed on the outer peripheral surface of this shaft member 60. On the other hand, a bracket 70 having a flange contact portion 72 formed to abut against the outer peripheral flange portion 66 from the base end side of the shaft member 60 is attached to the first housing 52. In addition, a pressing member 80 is arranged between the side end of the second reflector 40 and the bracket 70 to elastically press the flange contact portion 72 toward the outer peripheral flange portion 66, so that the following effects can be obtained.

[0097] In other words, the second reflector 40 is positioned in the left-right direction by the contact between the flange contact portion 72 and the outer peripheral flange portion 66, and this positioning state can be reliably maintained by the pressing member 80, thereby improving the positional accuracy of the second reflector 40.

[0098] Thus, according to this embodiment, in an image illumination device 10 configured to illuminate an image display unit with light emitted from an image generation unit 20 via first and second reflectors 30 and 40, the positional accuracy of the second reflector 40 can be improved.

[0099] Furthermore, in this embodiment, the outer peripheral flange portion 66 of the shaft member 60 has a conical surface shape centered on the axis Ax, and the flange contact portion 72 of the bracket 70 has a conical surface shape formed to make surface contact with this outer peripheral flange portion 66. As a result, the shaft member 60 can be stably held in a centered state, thereby further improving the positional accuracy of the second reflector 40.

[0100] In this embodiment, the outer peripheral flange portion 66 of the shaft member 60 is formed with a portion of it missing in the circumferential direction, while the bracket 70 has an insertion hole 70Ba formed therein for inserting the shaft member 60 in the direction of the axis Ax. Furthermore, the flange contact portion 72 contacts the outer peripheral flange portion 66 of the shaft member 60, which is inserted into the insertion hole 70Ba and rotated around the axis Ax, from the base end side of the shaft member 60. This makes it easy to assemble the second reflector 40 to the bracket 70.

[0101] In this embodiment, the bracket 70 is formed with two pairs of projections 76 that limit the rotatable angle of the second reflector 40 around its axis Ax to a predetermined angle range by contact with the circumferential end faces of a pair of outer flange portions 66. This effectively prevents the second reflector from inadvertently detaching from the bracket 70 due to vehicle vibration or the like.

[0102] Furthermore, in this embodiment, since such a support structure is employed on both the left and right sides of the second reflector 40, the positional accuracy of the second reflector 40 can be maximized.

[0103] Furthermore, in this embodiment, an actuator 90 for rotating the second reflector 40 around the axis Ax is supported on the bracket 70, and this actuator 90 is equipped with an output shaft 92 extending in the left-right direction, and this output shaft 92 is connected to the tip of the shaft member 60, so the actuator 90 can be easily positioned.

[0104] In the first embodiment described above, the outer peripheral flange portion 66 of the shaft member 60 and the flange contact portion 72 of the bracket 70 were both described as having a conical surface shape centered on the axis Ax. However, the flange contact portion 72 of the bracket 70 can also be configured with a circular opening or the like centered on the axis Ax.

[0105] While adopting this configuration results in a less stable holding of the shaft member 60 in a centered state compared to the first embodiment described above, it is still possible to ensure the function of holding the shaft member 60 in a centered state.

[0106] In the first embodiment described above, the second reflector 40 was described as being supported in the first housing 52 so as to be rotatable around an axis Ax extending in the left-right direction. However, it is also possible to configure it to be supported so as to be rotatable around an axis extending in a direction inclined in the front-back direction or the up-down direction with respect to the left-right direction.

[0107] In the first embodiment described above, the image illumination device 10 was described as having first and second reflectors 30 and 40. However, it is also possible to have a configuration with only a single reflector (specifically, only the second reflector 40), and even when such a configuration is adopted, it is possible to obtain substantially the same effects as in the first embodiment.

[0108] In the first embodiment described above, the image display unit 102A was described as being set on the inner surface of the front windshield 102, but it is also possible to configure the image display unit with a light-transmitting plate or the like that is placed on the interior side of the front windshield 102.

[0109] In the first embodiment described above, the image projection device 10 was described as an in-vehicle head-up display, but it can also be used for other purposes.

[0110] Next, a second embodiment of the present invention will be described.

[0111] Figure 11 is a diagram similar to Figure 4, showing the image irradiation device 110 according to this embodiment.

[0112] As shown in Figure 11, the basic configuration of the image illumination device 110 according to this embodiment is the same as that of the first embodiment described above, but the configuration of the left and right ends of the second reflector 140 and the support structure of the second reflector 140 differ from those of the first embodiment, and consequently the configuration of the first housing 152 also differs in part from that of the first embodiment.

[0113] In other words, the second reflector 140 of this embodiment has a configuration in which a pair of left and right plate-shaped flange portions 142 are formed on both the left and right ends on its back side, extending forward along a vertical plane, and furthermore, cylindrical first and second shaft portions 144 and 146 are formed from these left and right pair of plate-shaped flange portions 142, extending in both left and right directions.

[0114] The first shaft portion 144, located on the left side, is supported by a bearing fitting 160 fixed to the lower wall portion 152b of the first housing 152, so as to be rotatable around an axis Ax extending in the left-right direction.

[0115] The bearing fitting 160 is integrally formed as a metal press-molded product, with the base portion 162, the bearing portion 164, and the shaft retaining piece 166 being the same.

[0116] The base portion 162 is formed in a flat plate shape that extends long in the front-to-back direction, and an opening 162a extending in the front-to-back direction is formed in its central part.

[0117] The bearing portion 164 is formed to conform to the outer circumferential shape of the first shaft portion 144 by deforming the portion of the opening 162a in the base portion 162 on the second reflector 140 side upward.

[0118] The shaft retaining piece 166 is formed to extend forward from the rear end of the base portion 162 within the opening 162a.

[0119] Furthermore, the bearing fitting 160 is configured such that a substantially circular space is formed between its bearing portion 164 and the shaft retaining piece 166 when viewed from the side. In this case, the vertical width of this space is slightly smaller than the diameter of the first shaft portion 144.

[0120] The bearing fitting 160 is fastened and fixed to the lower wall portion 152b of the first housing 152 by screws 182 at two locations, front and rear, of its base portion 162.

[0121] The second reflector 140 is supported by the bearing portion 164 in an engaged state with the shaft retaining piece 166 by inserting the first shaft portion 144A into the space formed by the bearing portion 164 and the shaft retaining piece 166 of the bearing fitting 160 fixed to the first housing 152. At this time, the bearing fitting 160 is elastically deformed upward by the shaft retaining piece 166 coming into contact with the outer circumferential surface of the first shaft portion 144, thereby holding the first shaft portion 144 in a state supported by the bearing portion 164.

[0122] On the other hand, the second shaft portion 146 is configured such that the region on its base end side is a large-diameter portion 146A with a larger diameter than the first shaft portion 144, and the region on its tip end side is configured as a small-diameter portion 146B with the same diameter as the first shaft portion 144.

[0123] Figure 12 is a detailed view of section XII in Figure 11, and Figure 13 is a cross-sectional view taken along line XIII-XIII in Figure 11.

[0124] As shown in Figures 12 and 13, the second shaft portion 146 has an outer peripheral flange portion 146C formed at the tip of its small diameter portion 146B. The outer peripheral flange portion 146C has a surface 146Ca on its back side (i.e., the side of the small diameter portion 146B) that is formed as a conical surface centered on the axis Ax.

[0125] On the other hand, a bracket 170 equipped with a bearing portion 172 for supporting the second shaft portion 146 is attached to the lower wall portion 152b of the first housing 152.

[0126] The bearing portion 172 has a U-shaped cross-section with an open area located above the axis Ax, and is configured to support the small-diameter portion 146B of the second shaft portion 146, which is inserted from above, from below.

[0127] The bearing portion 172 has a flange contact portion 174 that abuts against the outer peripheral flange portion 146C of the second shaft portion 146 from its back side. The surface 174a of this flange contact portion 174 that abuts against the outer peripheral flange portion 146C is formed as a conical surface centered on the axis Ax, and its inclination angle is set to the same value as the surface 146Ca of the outer peripheral flange portion 146C. As a result of the surface contact between the surface 174a of the flange contact portion 174 and the surface 146Ca of the outer peripheral flange portion 146C, the second shaft portion 146 extends in the left-right direction while being centered on the axis Ax.

[0128] Between the large-diameter portion 146A of the second shaft portion 146 and the bearing portion 172 of the bracket 170, a pressing member 180 is positioned to elastically press the flange contact portion 174 toward the outer peripheral flange portion 146C.

[0129] The pressing member 180 is made of a metal coil spring attached to the small diameter portion 146B of the second shaft portion 146. The pressing member 180 is positioned in a compressed state in the left-right direction, with one end 180a locked to a spring locking portion 148 formed at the tip of the large diameter portion 146A, and the other end 180b locked to a spring locking portion 176 formed on the bracket 170. Because the pressing member 180 is made of such a coil spring, the second reflector 40 is constantly biased to rotate forward around the axis Ax, thereby enabling accurate positioning in the direction of the axis Ax.

[0130] Bracket 170 supports an actuator 190 for rotating the second reflector 140 around axis Ax. This actuator 190 has an output shaft 192 that extends horizontally forward below the second shaft portion 146, and this output shaft 192 is connected to the second shaft portion 146 via a worm gear 200.

[0131] The worm gear 200 is constructed by forming a worm wheel tooth profile 200A on the outer circumferential surface of the tip of the large-diameter portion 146A of the second shaft portion 146, with axis Ax as the rotation center, and forming a worm tooth profile 200B that meshes with the worm wheel tooth profile 200A on an extension shaft member 194 that is coaxially attached to the output shaft 192 of the actuator 190.

[0132] The bracket 170 has a support hole 170a formed therein for rotatably supporting the tip of the extension shaft member 194.

[0133] The bracket 170 is fastened and secured to the lower wall portion 152b of the first housing 152 by screws 184 at two locations on its left and right sides. The actuator 190 is fastened and secured to the bracket 170 by screws 186 at two locations on its rear wall portion.

[0134] Even when adopting the configuration of this embodiment, substantially the same effects and advantages as those of the first embodiment can be obtained.

[0135] In other words, in this embodiment, a bearing portion 172 for supporting the second shaft portion 146 (shaft member) is formed in the bracket 170, and this bearing portion 172 has a U-shaped cross-sectional shape with its upper part (a part in the circumferential direction) open, and the flange contact portion 174 of the bearing portion 172 is configured to contact the outer peripheral flange portion 146C of the second shaft portion 146 supported by the bearing portion 172 from the base end side of the second shaft portion 146, so that the second reflector 140 can be easily assembled to the bracket 170.

[0136] In this configuration, the outer peripheral flange portion 146C of the second shaft portion 146 has a conical surface shape centered on the axis Ax, and the flange contact portion 174 of the bearing portion 172 has a conical surface shape formed to make surface contact with the outer peripheral flange portion 146C. As a result, the second shaft portion 146 can be stably held in a centered state, thereby further improving the positional accuracy of the second reflector 140.

[0137] In this embodiment, an actuator 190 for rotating the second reflector 140 (reflector) around the axis Ax is supported on the bracket 170, and a worm wheel tooth profile with axis Ax as the rotation center is formed on the outer circumferential surface of the second shaft portion 146, and an extended second shaft portion 146 having a worm tooth profile 200B that meshes with the worm wheel tooth profile 200A is attached to the output shaft 192 of the actuator 190, so that the rotation angle of the second reflector 140 can be adjusted with high precision.

[0138] Furthermore, since the bracket 170 has a support hole 170a for rotatably supporting the tip of the extension shaft member 194, the extension shaft member 194 can be reliably supported in this support hole 170a, thereby further improving the adjustment accuracy of the rotation angle of the second reflector 140.

[0139] In particular, in this embodiment, the bearing fitting 160 and bracket 170 are fixed to the lower wall portion 152b of the first housing 152 in advance, and the second reflector 140 can be assembled by engaging the first shaft portion 144 of the second reflector 140 with the bearing fitting 160 and engaging the second shaft portion 146 with the bearing portion 172, thereby improving the workability of assembling the second reflector 140.

[0140] In addition, in the configuration of the first embodiment described above, instead of the support structure of the shaft member 70 at the left end of the second reflector 40, it is also possible to adopt the support structure of the bearing fitting 160 of the first shaft portion 144 of the second reflector 140 in the second embodiment described above. [Explanation of Symbols]

[0141] 2 drivers 10 Image irradiation device 12 Interior space 20 Image Generation Units 22 LCD panels 30 1st reflector 30a, 40a reflective surface 32 Flange section 32A Side wall part 32B Staircase 34, 82, 84, 86 screws 40 Second reflector (reflector) 42 Plate-shaped flange portion 50 Housing 52 Housing 1 52a Top opening 52b Lower wall part 52d Unit mounting section 52e, 54a, 82Aa opening 52f Columnar projection 52g pin 52k positioning pins 54 Second Housing 54a opening 54b Outer flange portion 54c Light shielding piece 56 Translucent cover 60 Shaft member 60a Engagement hole 62 Shaft body 64 Reflector connection part 66 Outer flange section 66a, 72a surface 70 bracket 70A base part 70Aa Positioning hole 70B Standing wall section 70Ba insertion hole 72 Flange contact area 74 Boss Section 76 Protrusion 80 Pressing member 90 Actuators 92 Output shaft 100 vehicles 102 Front windshield 102A Image display section 104 Steering Wheel 110 Image irradiation device 140 Second reflector (reflector) 142 Plate-shaped flange portion 144 First shaft section 146 2nd shaft part (shaft member) 146A Large diameter section 146B Small diameter section 146C Outer Flange Section 146Ca, 174a surface 148, 176 Spring locking part 152 Housing 1 152b Lower wall part 160 Bearing Fittings 162 Base part 164 Bearing section 166 Shaft retainer piece 162a opening 170 bracket 170a Support hole 172 Bearing section 174 Flange contact area 180 Pressing member 180a One end 180b Other end 182, 184, 186 screws 190 Actuator 192 Output shaft 194 Extension shaft member 200 Worm Gear 200A worm wheel tooth profile 200B worm tooth profile Ax axis PIC display image R optical path S Sunlight

Claims

1. In an image projection device configured to display an image on an image display unit, The system comprises an image generation unit that generates the above-mentioned display image, a reflector that reflects the light emitted from the image generation unit toward the image display unit, and a housing that accommodates the reflector. The above-mentioned reflector is supported in the housing so as to be rotatable about an axis extending in the required direction. A shaft member extending in the required direction is provided at the side end of the above-mentioned reflecting mirror. An outer peripheral flange portion is formed on the outer peripheral surface of the shaft member, extending in the circumferential direction with respect to the axis. A bracket having a flange contact portion formed to abut against the outer peripheral flange portion from the base end side of the shaft member is attached to the housing. An image irradiation device characterized in that a pressing member is positioned between the side end of the reflecting mirror and the bracket, which elastically presses the flange contact portion toward the outer peripheral flange portion.

2. The outer circumferential flange portion has a conical surface shape centered on the axis, The image irradiation device according to claim 1, characterized in that the flange contact portion has a conical surface shape formed to make surface contact with the outer peripheral flange portion.

3. The image irradiation device according to claim 1 or 2, characterized in that the pressing member is composed of a coil spring attached to the shaft member, with one end being locked to the reflector and the other end being locked to the bracket.

4. The outer flange portion described above is formed with a portion of it missing in the circumferential direction. The bracket has an insertion hole formed therein for inserting the shaft member in the axial direction. The image irradiation device according to claim 1 or 2, characterized in that the bracket is configured such that the flange contact portion contacts the outer peripheral flange portion of the shaft member, which is inserted into the through hole and rotated around the axis, from the base end side of the shaft member.

5. The image irradiation device according to claim 4, characterized in that the bracket has a projection formed thereon that limits the rotatable angle of the reflector around the axis to a predetermined angular range by contact with the circumferential end face of the outer flange portion.

6. An actuator for rotating the reflector around the axis is supported on the bracket mentioned above. The actuator described above is equipped with an output shaft extending in the required direction, The image irradiation device according to claim 1 or 2, characterized in that the output shaft is connected to the tip of the shaft member.

7. The bracket has a bearing portion formed therein for supporting the shaft member. The bearing portion described above has a U-shaped cross-section with a portion of its circumferential direction open. The image irradiation device according to claim 1 or 2, characterized in that the bracket is configured such that the flange contact portion contacts the outer peripheral flange portion of the shaft member supported by the bearing portion from the base end side of the shaft member.

8. An actuator for rotating the reflector around the axis is supported on the bracket mentioned above. A worm wheel tooth profile is formed on the outer circumferential surface of the shaft member, with the axis mentioned above as the rotation center. The image irradiation device according to claim 1 or 2, characterized in that an extension shaft member having a worm tooth profile that meshes with the worm wheel tooth profile is attached to the output shaft of the actuator described above.

9. The image irradiation device according to claim 8, characterized in that the bracket has a support hole formed therein for rotatably supporting the tip of the extension shaft member.

Images