JP2010076666A - Head-up display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a head-up display device attaining enhancement of mountability by miniaturization while maintaining a successful display image. <P>SOLUTION: The head-up display device 100 projects the display image 99 onto a windshield 91 provided in a visual recognition direction of a visual recognition person. The head-up display device 100 includes: a light source part 30 for radiating a light flux for making the display image 99 emit light; a lens 40 for refracting the light flux from the light source part 30 in a direction along an optical axis 40ax; a reflection mirror part 60 for reflecting the light flux refracted by the lens 40 toward the windshield 91; and a housing 20 having a light source retaining part 126 for retaining the light source part 30, a lens retaining part 24 for retaining the lens 40, and a sidewall part 22 for retaining the reflection mirror part 60. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a head-up display device that projects a display image on a projection member.

  Conventionally, a light source unit that emits a light beam for emitting a display image, a lens that refracts the light beam from the light source unit toward the optical axis, and a reflecting mirror unit that reflects the light beam refracted by the lens toward the projection member There is known a head-up display device comprising: For example, the head-up display device disclosed in Patent Document 1 includes a case body having a light source holding part that holds a light source part and a lens holding part that holds a lens. The light source unit and the lens are held in a case body. In addition, the head-up display device includes a housing having a case body holding portion that holds the case body together with a reflecting mirror holding portion that holds the reflecting mirror portion. The case body that holds the light source part and the lens is assembled to the case body holding part of the housing.

Now, in the head-up display device, when the position of the optical axis of the lens with respect to the light source unit is shifted and the light beam incident on the lens becomes non-uniform in the direction orthogonal to the optical axis of the lens, The light beam refracted by the light becomes non-uniform. Thereby, luminance unevenness occurs in the display image projected on the projection member. In order to prevent luminance unevenness of the display image, in the head-up display device disclosed in Patent Document 1, the light source unit and the lens are held in the same case body. With this configuration, since the positional accuracy of the light source unit with respect to the optical axis of the lens becomes good, the light beam emitted from the light source unit and refracted by the lens toward the optical axis becomes uniform.
JP 2007-114743 A

  In the head-up display device disclosed in Patent Document 1, a housing and a case body are interposed between the reflecting mirror portion and the lens. Thereby, the variation in the optical axis direction of the lens position with respect to the reflecting mirror portion is increased due to the processing accuracy of the housing and the case body and the accuracy of assembling the case body to the case body holding portion of the housing. Therefore, there is a concern that the light beam refracted by the lens reaches a position shifted from a predetermined position of the reflecting mirror portion. Due to the shift of the position where the light beam reaches the reflecting mirror part, a part of the display image projected on the projection member is lost. In order to prevent the display image from being lost, it is necessary to provide a margin for allowing the deviation of the arrival position of the light beam in the reflecting mirror portion. As a result, the reflector portion has been forced to increase in size. And the size reduction of a head-up display apparatus is prevented by the enlarged reflective mirror part.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a head-up display device that realizes an improvement in mountability by miniaturization while maintaining a good display image.

  In order to achieve the above-mentioned goal, according to the first aspect of the present invention, there is provided a head-up display device that projects a display image onto a projection member provided in a viewing direction of a viewer, and a luminous flux for emitting the display image. A light source unit that emits light, a lens that refracts a light beam from the light source unit in a direction along the optical axis, a reflecting mirror unit that reflects the light beam refracted by the lens toward the projection member, and a first that holds the light source unit A housing having a holding part, a second holding part for holding the lens, and a third holding part for holding the reflecting mirror part.

  According to this invention, since the light source unit and the lens are held in the same housing by the first holding unit and the second holding unit, the positional accuracy of the light source unit with respect to the optical axis of the lens is good. Therefore, the luminous flux emitted from the light source unit and refracted by the lens toward the optical axis side becomes uniform, so that the luminance unevenness of the display image is suppressed. In addition, since the lens and the reflecting mirror part are held in the same housing by the second holding part and the third holding part, variation in the optical axis direction of the lens with respect to the reflecting mirror part is suppressed. Therefore, the light beam refracted by the lens can reach a predetermined position of the reflecting mirror portion. According to these, even if the reflecting mirror portion is formed with a minimum size, the occurrence of chipped display images hardly occurs. Since the reflecting mirror portion is small, the head-up display device can be miniaturized, so that mountability can be improved while maintaining a good display image.

In the invention described in claim 2, the second holding portion also serves as the first holding portion. According to this invention,
The light source unit is held by the second holding unit that also serves as the first holding unit. Since the light source unit and the lens are held by the same second holding unit, the positional accuracy of the light source unit with respect to the optical axis of the lens is further improved. As a result, the luminous flux emitted from the light source unit and refracted by the lens toward the optical axis side becomes uniform, so that the luminance unevenness of the display image is suppressed. In addition, by omitting the first holding part, it is possible to contribute to miniaturization of the head-up display device. Therefore, mountability can be improved while maintaining a good display image.

  According to a third aspect of the present invention, the lens has an adjustment portion whose position is adjustable in a direction perpendicular to the optical axis with respect to the housing. According to the present invention, the position of the lens is adjusted in the direction orthogonal to the optical axis by the adjustment unit, and then held by the second holding unit of the housing. Therefore, the position of the lens can be adjusted so that the optical axis of the lens is accurately positioned with respect to the light source unit. As a result, the light beam emitted from the light source unit and refracted to the optical axis side by the lens becomes uniform, so that even if the light source unit and the lens are held in the housing, uneven brightness of the display image is reliably suppressed. Is done. Therefore, it is possible to provide a head-up display device with improved mountability while maintaining a good display image.

  In the invention according to claim 4, the adjusting portion has a mounting portion having a plane orthogonal to the optical axis, and a mounting hole provided in the mounting portion in a direction along the optical axis, and the lens is loosened in the mounting hole. It attaches to a 2nd holding | maintenance part with the fastening member to fit. According to the present invention, the mounting hole provided in the direction along the optical axis in the mounting portion and the fastening member for holding the lens in the housing are loosely fitted to each other, so that the direction perpendicular to the optical axis of the lens is increased. Position adjustment can be allowed. Therefore, the position of the lens is adjusted in a direction orthogonal to the optical axis along the plane of the mounting portion. And by fastening of a fastening member, a lens is hold | maintained at the 2nd holding | maintenance part of a housing in the state arrange | positioned so that the optical axis of the said lens may be correctly located with respect to a light source part.

  In the invention according to claim 5, the light source unit and the lens are provided with a positioning mechanism for positioning the lens in the direction orthogonal to the optical axis with respect to the light source unit. According to this invention, the lens is positioned with respect to the light source unit by the positioning mechanism provided in the lens and the light source unit. Therefore, by holding the lens and the light source unit by the housing, the position is automatically adjusted so that the optical axis of the lens is accurately positioned with respect to the light source unit. Thereby, the light beam refracted by the lens toward the optical axis can be made uniform without providing a lens position adjusting step. Therefore, since the luminance unevenness of the display image is surely suppressed, it is possible to provide a head-up display device with improved mountability while maintaining a good display image.

  In addition, according to the second aspect of the present invention, the position of the lens can be adjusted by a positioning mechanism in a direction perpendicular to the optical axis with respect to the second holding portion of the housing. Therefore, the regulating force of the position in the direction orthogonal to the optical axis does not act from the housing. Thereby, the lens positioned by the positioning mechanism in the direction orthogonal to the optical axis with respect to the light source unit is not distorted in the direction orthogonal to the optical axis. Accordingly, the optical axis shift of the lens due to distortion does not occur, and a uniform light beam can be emitted from the lens.

  In the invention according to claim 6, the positioning mechanism is a positioning pin provided in the lens and projecting from the lens to the light source unit, and a positioning hole provided in the light source unit and into which the positioning pin is fitted. According to the present invention, the lens is positioned and fixed in the direction perpendicular to the optical axis of the positioning mechanism with respect to the light source unit by fitting the positioning pin protruding from the lens to the light source unit into the positioning hole of the light source unit. . With such a simple configuration, the lens can be held in the housing in a state where the lens is arranged so that the optical axis of the lens is accurately positioned with respect to the light source unit.

  In a seventh aspect of the present invention, the housing has a peripheral wall portion that annularly surrounds the radially outer side of the lens, and the second holding portion is provided on the peripheral wall portion. There is a concern that the housing may be deformed by an externally applied stress. In the configuration in which the lens is held by the second holding portion provided in the housing, the second holding portion is deformed by the distortion of the housing, and the optical axis direction of the lens held by the second holding portion is deviated from a predetermined direction. There is a fear. Therefore, by forming a peripheral wall portion that annularly surrounds the radially outer side of the lens in the housing and providing the second holding portion on the peripheral wall portion, the rigidity in the vicinity of the second holding portion can be improved. Since the lens is held by the highly rigid second holding portion, it is possible to suppress the deviation of the lens in the optical axis direction even when external stress is applied to the housing. Thereby, the light beam emitted from the light source unit is accurately refracted toward the optical axis side of the lens and reliably reaches a predetermined position of the reflecting mirror unit. Therefore, the reflecting mirror portion can be formed with a minimum size.

  According to the eighth aspect of the invention, the opening on the light source unit side of the peripheral wall is closed by the light source unit. According to this invention, since the opening of the peripheral wall portion is closed by the light source portion, the rigidity of the peripheral wall portion can be further increased. Therefore, since the lens is held by the second holding portion provided on the peripheral wall portion having further increased rigidity, even if the housing is subjected to external stress, the lens is reliably displaced in the optical axis direction. It is suppressed.

  According to the ninth aspect of the present invention, a transmissive display panel is provided on the reflecting mirror portion side of the lens in a direction orthogonal to the optical axis, and the housing protrudes radially inward from the peripheral wall portion, and the transmissive display panel is It has the 4th holding part to hold. According to the present invention, the fourth holding portion protruding radially inward from the peripheral wall portion serves as a rib that holds the transmissive display panel and improves the rigidity of the peripheral wall portion. Therefore, since the lens is held by the second holding portion provided on the peripheral wall portion having further increased rigidity, even if the housing is subjected to external stress, the lens is reliably displaced in the optical axis direction. It is suppressed.

  In addition, since the fourth holding part and the second holding part that hold the transmissive display panel and the lens are held on the same peripheral wall part, variations in the optical axis direction of the lens with respect to the transmissive display panel are suppressed. Therefore, the light beam refracted by the lens can pass through a predetermined position of the transmissive display panel. This eliminates the need for a margin for the transmissive display panel, so that a transmissive display panel with a minimum size can be selected, which can contribute to the miniaturization of the head-up display device.

  In a tenth aspect of the present invention, the reflecting mirror section has a plurality of reflecting mirrors. As described above, according to the effect of reducing the variation in the optical axis direction by directly holding the lens in the housing in which the reflecting mirror portion is held, the light flux emitted from the light source is transmitted to the predetermined position of the reflecting mirror portion. To be reached. The reflecting mirror located on the side farther from the lens in the reflecting mirror section having a plurality of reflecting mirrors exhibits a remarkable effect of reducing variation in the optical axis direction of the lens, and can be greatly reduced in size by reducing the margin. . Therefore, the present invention is particularly suitable for a head-to-head display device having a reflecting mirror section having a plurality of reflecting mirrors.

  In the invention described in claim 11, the reflecting mirror portion has a concave mirror. The curved concave mirror is larger in the thickness direction than the plane mirror, and occupies a large space in the head-up display device. Therefore, the reduction of the margin of the concave mirror by exerting the effect of reducing the variation in the optical axis direction of the lens significantly contributes to the downsizing of the head-up display device. Therefore, the present invention is particularly suitable for a head-to-head display device having a reflecting mirror portion having a concave mirror.

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

  FIG. 1 shows a vehicle equipped with a head-up display device 100 according to an embodiment of the present invention. The head-up display device 100 is installed inside an instrument panel 93 provided in the viewing direction of the viewer, and projects a display image 99 on the windshield 91.

(Basic configuration)
As shown in FIG. 2, the head-up display device 100 includes a light source unit 30, a lens 40, a liquid crystal panel 51, a reflecting mirror unit 60, a housing 20, and a main substrate 73 (see FIG. 3).

  As shown in FIG. 3, the light source unit 30 includes a light emitting diode 31, a sub board 33, a fastening hole 34, and a screw 39. The light emitting diode 31 is a semiconductor element that emits a light beam when a voltage is applied, and emits a white light beam toward the lens 40 side. The sub-board 33 is a rectangular circuit board made of a hard material of paper phenol type or glass epoxy type. A predetermined wiring pattern (not shown) made of a copper foil material is formed on the surface of the sub-board 33 on the lens 40 side, and the light emitting diode 31 electrically connected to the wiring pattern is mounted. In addition, an LED drive circuit (not shown) for applying a voltage to the light emitting diode 31 is formed on the sub-board 33. Thereby, a voltage is applied to the light emitting diode 31 via the LED driving circuit on the sub-board 33. The fastening holes 34 are through-holes provided in the plate thickness direction at corners located diagonally of the rectangular sub-board 33 (see FIG. 4). The screw 39 passes through the fastening hole 34 and is fastened to the housing 20. The light source unit 30 is held with respect to the housing 20 by fastening the screw 39.

  The lens 40 is formed of a highly translucent resin material optimized for optics, and is held by the housing 20. The lens 40 forms a smooth incident surface 43 on the light source unit 30 side and an exit surface 42 that is convex toward the outside on the side opposite to the incident surface 43. At the center of the lens 40, there is an optical axis 40ax along the thickness direction of the lens. The light beam incident on the lens 40 from the incident surface 43 side is refracted to the optical axis 40ax side and emitted from the emission surface 42 side, at least one of the incident surface 43 and the emission surface 42.

  The liquid crystal panel 51 is a rectangular plate-shaped transmissive display panel, and is disposed at a position facing the emission surface 42 of the lens 40 in a direction orthogonal to the optical axis 40ax of the lens 40. The liquid crystal panel 51 is previously formed with a plurality of segments whose light transmittance is changed by application of a voltage. The liquid crystal panel 51 forms the design of the display image 99 by controlling the passage of the light beam emitted from the emission surface 42 by the segment. The liquid crystal panel 51 is attached to the housing 20 with a double-sided tape 53. The liquid crystal panel 51 corresponds to a “transmissive display panel” recited in the claims.

  As shown in FIG. 2, the reflecting mirror unit 60 is formed by combining a plurality of reflecting mirrors such as a plane mirror 61 and a concave mirror 66. The plane mirror 61 has a rectangular plate shape, and is formed by a base material such as glass and a reflecting surface 61a formed by an aluminum deposition surface formed on the surface of the base material. The plane mirror 61 is disposed with the reflecting surface 61a facing the emission surface 42 side and the concave mirror 66 side, and is held at a predetermined angle with respect to the housing 20 by a double-sided tape 63 or the like. The concave mirror 66 is formed by a base material such as glass curved in the thickness direction and a concave mirror surface 66a formed by vapor deposition of aluminum or the like formed on the concave surface of the base material. The concave mirror 66 is disposed toward the windshield 91 (see FIG. 1) in the traveling direction of the light beam reflected by the plane mirror 61 and is held at a predetermined angle with respect to the housing 20. Due to the arrangement of the flat mirror 61 and the concave mirror 66, the light beam that has passed through the liquid crystal panel 51 is reflected toward the windshield 91 (see FIG. 1).

  As shown in FIG. 3, the housing 20 is a bottomed container made of a resin material such as polypropylene and forming a bottom wall portion 21 and a side wall portion 22. In the housing 20, the light source unit 30, the lens 40, the liquid crystal panel 51, the reflecting mirror unit 60, and the like are accommodated. A plurality of bosses 21 a are provided on the outer surface side of the bottom wall portion 21 of the housing 20 in a direction orthogonal to the bottom wall portion 21. Further, the inside of the side wall portion 22 of the housing holds the flat mirror 61 and the concave mirror 66 via the double-sided tape 63, and corresponds to a “third holding portion” recited in the claims. Further, a black coating is applied to the inner side surface of the housing 20 to suppress reflection of extraneous light entering the housing 20. In addition, as shown in FIG. 1, a dust-proof cover 27 made of a translucent resin material such as acrylic is fitted on the upper surface of the housing 20. The dust cover 27 prevents dust and dirt from entering the housing 20 and transmits the light beam reflected by the concave mirror 66 toward the windshield 91.

  As shown in FIG. 3, the main board 73 is a circuit board made of a paper phenolic or glass epoxy hard material, and the main board 73 is formed in a shape following the planar shape of the bottom wall portion 21 of the housing 20. Has been. The main board 73 is held by the housing by being fastened to a boss 21 a provided on the outer surface side of the bottom wall portion 21 at a plurality of locations by screws 79. Further, a predetermined wiring pattern (not shown) made of a copper foil material is formed on the main substrate 73, and the wiring pattern constitutes a liquid crystal driving circuit (not shown) of the liquid crystal panel 51. The liquid crystal driving circuit applies a voltage to each segment provided in the liquid crystal panel 51 via a flexible substrate (not shown) that electrically connects the main substrate 73 and the liquid crystal panel 51. Further, the main board 73 is also connected to the sub board 33 by a flexible board. Power is supplied to the LED drive circuit provided on the sub board 33 via the main board 73.

  As shown in FIG. 1, the instrument panel 93 that houses the head-up display device 100 is made of a resin material and is attached to a structural member (not shown) of the vehicle. The head-up display device 100 is held and fixed inside the instrument panel 93 via a plurality of brackets (not shown) attached to the instrument panel 93 or a vehicle structural member. A windshield 91 made of tempered glass is located on the upper surface side of the head-up display device 100. The windshield 91 is curved so as to be concave toward the head-up display device 100 side. The windshield 91 corresponds to a “projection member” described in the claims in which the display image 99 is projected.

  The projection of the display image 99 by the head-up display device 100 having the above configuration will be described.

  The light beam emitted radially by the light emitting diode 31 is refracted by the lens 40 toward the optical axis 40ax. As a result, most of the light beam travels straight in the direction along the optical axis 40ax and reaches the liquid crystal panel 51. Then, the light beam that has passed through each segment of the liquid crystal panel 51 is sequentially reflected by the plane mirror 61, the concave mirror 66, and the windshield 91, and reaches the viewer. Here, the optical path distance from the liquid crystal panel 51 to the plane mirror 61 is D1, the optical path distance from the plane mirror 61 to the concave mirror 66 is D2, the optical path distance from the concave mirror 66 to the inner surface of the windshield 91 is D4, and the viewer is from the windshield 91 to the viewer. The optical path distance to is D6.

  First, a projection image 99 a having the design of the display image 99 is formed by the light flux that has passed through the liquid crystal panel 51. Then, the projected image 99a is reflected by the concave mirror 66, thereby becoming a projected virtual image 99b displayed at a distance D3 on the opposite side of the concave mirror 66 from the concave mirror surface 66a. This is because the sum of D1 and D2 is set to be shorter than the focal length of the concave mirror. The projected virtual image 99b is an enlarged image of the projected image 99a. Further, the projected virtual image 99 b is projected toward the inner surface of the windshield 91. The windshield 91, which is curved so as to be concave toward the head-up display device 100, has an optical function similar to that of the concave mirror 66. Since the focal length of the windshield 91 is much longer than the sum of D3 and D4, the display image 99 is formed at the position D5 on the front side in the viewing direction. The display image 99 is an enlarged image of the projected virtual image 99b. The viewer can visually recognize the display image 99 at the sum of D5 and D6.

  Factors that degrade the display quality of the head-up display device 100 configured as described above are uneven luminance of the display image 99 and lack of display. The luminance unevenness of the display image 99 is caused by the shift of the position of the optical axis 40ax of the lens 40 with respect to the light emitting diode 31 of the light source unit 30. When the position of the optical axis 40ax is shifted with respect to the light emitting diode 31, the light beam incident on the incident surface 43 of the lens 40 becomes non-uniform. As a result, the light beam refracted to the optical axis 40ax side by the lens 40 also becomes non-uniform, resulting in uneven brightness of the display image 99. In addition, the lack of display of the display image 99 is caused by a shift in the direction of the optical axis 40ax of the lens 40 with respect to the reflecting mirror unit 60. When the light beam refracted by the lens 40 reaches a position deviated from a predetermined position of the plane mirror 61, a part of the projection image 99a to be reflected deviates from the reflection surface 61a of the plane mirror 61. As a result, depending on the viewpoint position of the viewer, a part of the display image 99 projected on the windshield 91 is missing.

(Characteristic part)
Hereinafter, characteristic parts of the head-up display device 100 according to an embodiment of the present invention will be described.

  As shown in FIG. 3 or FIG. 4, the housing 20 has a lens holding part 24 that holds the light source part 30 and the lens 40. In this embodiment, the lens holding unit 24 corresponds to the “second holding unit” described in the claims for holding the lens 40 and also serves as a light source holding unit for holding the light source unit 30. It corresponds to the “first holding part” described in the above.

  Further, the housing 20 has a peripheral wall portion 23 that annularly surrounds the radially outer side of the lens 40. The peripheral wall portion 23 is provided with a lens holding portion 24 and a rib 25, and accommodates the light source portion 30, the lens 40, and the liquid crystal panel 51. The lens holding part 24 is configured by an end face 24a orthogonal to the optical axis 40ax of the lens 40, a screw hole in which a screw part that fits the screw 39 is formed, and the like. The ribs 25 are convex portions that protrude radially inward from the inner peripheral surface of the peripheral wall portion 23. A liquid crystal panel 51 is attached to the surface of the rib 25 on the lens 40 side by a double-sided tape 53. Therefore, the rib 25 holds the liquid crystal panel 51 via the double-sided tape 53 and corresponds to a “fourth holding portion” recited in the claims. In addition, a transmission window 25 a for the light beam that has passed through the liquid crystal panel 51 is formed by an opening on the radially inner side of the rib 25.

  The lens 40 has a mounting portion 44 and a positioning pin 46. The attachment portion 44 includes a plane 44a orthogonal to the optical axis 40ax of the lens 40 and an attachment hole 44b provided in a direction along the optical axis 40ax. The flat surface 44 a is in contact with the end surface 24 a of the lens holding portion 24, thereby determining the direction of the optical axis 40 ax of the lens 40. The mounting hole 44 b is formed at a position that is coaxial with the fastening hole 34 of the sub-board 33, and has a larger diameter than the nominal diameter of the screw 39 so as to be loosely fitted with the screw 39. The positioning pin 46 is provided on the mounting portion 44 of the lens 40 and protrudes from the lens 40 toward the light source portion 30 in the direction along the optical axis 40ax.

  The light source unit 30 has a positioning hole 36 provided in a direction along the optical axis 40ax. The positioning holes 36 are formed in the sub-board 33 and are provided at diagonal positions with the light emitting diode 31 as the center. The positioning hole 36 is fitted with the positioning pin 46.

  The attachment portion 44 corresponds to an “adjustment portion” described in the claims. With the mounting portion 44, the position of the lens 40 can be freely adjusted with respect to the housing 20 in a direction orthogonal to the optical axis 40ax of the lens 40. In addition, the positioning pin 46 and the positioning hole 36 correspond to a “positioning mechanism” described in the claims. When the positioning pin 46 is fitted into the positioning hole 36, the lens 40 can be positioned with respect to the light source unit 30 in a direction orthogonal to the optical axis 40 ax.

  In the head-up display device 100 having the above configuration, attachment of the lens 40 and the light source unit 30 to the housing 20 will be described. First, the lens 40 is accommodated in the peripheral wall portion 23, and the end surface 24 a of the lens holding portion 24 and the flat surface 44 a of the lens 40 are brought into contact with each other. Thereby, the direction of the optical axis 40ax of the lens 40 with respect to the housing 20 is determined. In this state, the light source unit 30 is attached in the direction along the optical axis 40ax from the incident surface 43 side of the lens 40. As a result, the positioning pin 46 of the lens 40 is fitted into the positioning hole 36 of the light source unit 30, so that the lens 40 is positioned with respect to the light source unit 30 in a direction orthogonal to the optical axis 40 ax. Here, the position adjustment in the direction orthogonal to the optical axis 40ax of the lens 40 with respect to the light source unit 30 is allowed by the mounting hole 44 having a larger diameter than the outer diameter of the screw 39. Thereby, the screw 39 can penetrate the attachment hole 44b together with the fastening hole 34. In addition, the mounting hole 44 is not subjected to a regulating force in a direction orthogonal to the optical axis 40ax from the screw 39. When the screw 39 is fastened in this state, the position of the integrated part of the light source unit 30 and the lens 40 is adjusted in a direction perpendicular to the optical axis 40ax along the plane 44a provided to the housing 20 with respect to the mounting unit 44. Is done. Specifically, only the position of the optical axis 40ax is adjusted while the direction of the optical axis 40ax is maintained by sliding the plane 44a in a direction perpendicular to the optical axis 40ax with respect to the end surface 24.

  In the present embodiment, since the light source unit 30 and the lens 40 are held in the same housing 20 by the lens holding unit 24, the positional accuracy of the light source unit 30 with respect to the optical axis 40ax of the lens 40 is good. Specifically, the light emitting diode 31 mounted on the sub-substrate 33 can be disposed on the optical axis 40ax. Therefore, since the light beam emitted from the light emitting diode 31 of the light source unit 30 and refracted by the lens 40 toward the optical axis 40ax is uniform, the luminance unevenness of the display image 99 is suppressed. In addition, since the lens 40 and the plane mirror 61 and the concave mirror 66 of the reflecting mirror part 60 are held in the same housing 20 by the lens holding part 24 and the side wall part 22, the optical axis 40ax direction of the lens 40 with respect to the reflecting mirror part 60 Variation is suppressed. Therefore, the light beam refracted by the lens can reach a predetermined position of the reflecting mirror portion. According to these, even if the reflecting mirror part 60 is formed with a minimum size, it is difficult for the display image 99 to be missing. Therefore, since the head-up display device 100 can be downsized, the mountability to the vehicle can be improved while maintaining a good display image 99.

  In addition, in this embodiment, since the light source unit 30 and the lens 40 are held by the same lens holding unit 24, the positional accuracy of the light source unit 30 with respect to the optical axis 40ax of the lens 40 is further improved. As a result, the light beam emitted from the light emitting diode 31 of the light source unit 30 and refracted by the lens 40 toward the optical axis 40ax becomes uniform, and thus the luminance unevenness of the display image 99 is suppressed. In addition, by omitting the light source holding unit, it is possible to contribute to downsizing of the head-up display device 100. Therefore, the mountability to the vehicle can be improved while maintaining a good display image 99.

  In this embodiment, the lens 40 is positioned in a direction orthogonal to the optical axis 40ax along the plane 44a provided in the mounting portion 44, and the optical axis 40ax of the lens 40 is accurately positioned with respect to the light source unit 30. The lens holder 24 is held in such a state that it is arranged. Therefore, the light beam emitted from the light emitting diode 31 of the light source unit 30 and refracted by the lens 40 toward the optical axis 40ax side is uniform, so that even if the light source unit 30 and the lens 40 are held by the housing 20, The luminance unevenness of the display image 99 is surely suppressed and good display quality is maintained.

  Furthermore, in the present embodiment, the lens 40 is positioned with respect to the light source unit 30 by a positioning mechanism including the positioning pins 46 and the positioning holes 36 provided in the lens 40 and the light source unit 30. Therefore, by the process of holding the lens 40 and the light source unit 30 by the housing 20, the position is automatically adjusted so that the optical axis 40 ax of the lens 40 is accurately positioned with respect to the light emitting diode 31 of the light source unit 30. Thereby, the luminance unevenness of the display image 99 can be reliably suppressed without providing a process for adjusting the position of the lens 40. In addition, since the position of the lens 40 can be adjusted in the direction orthogonal to the optical axis 40ax, the lens 40 receives a regulating force in the direction orthogonal to the optical axis 40ax from the housing 20 to the mounting hole 44b via the screw 79. There is no. Therefore, since the lens positioned by the positioning mechanism is not distorted in the direction perpendicular to the optical axis, the displacement of the lens 40 in the optical axis 40ax direction due to distortion is not caused. Therefore, display defect of the display image 99 can be prevented and display quality can be maintained.

  There is a concern that the housing 20 of the head-up display device 100 may be deformed by externally acting stress. Specifically, the stress acting from the outside is a stress caused by mounting when mounted on a vehicle via a housing or a vibration transmitted from the vehicle. In this embodiment, since the lens 40 is held by the lens holding part 24 provided in the housing 20, the direction of the optical axis 40 ax of the lens 40 is caused by the distortion of the lens holding part 24 accompanying the deformation of the housing 20. There is a risk of deviation from a predetermined direction. Therefore, in the present embodiment, the peripheral wall portion 23 is formed in the housing 20 and the lens holding portion 24 is provided on the peripheral wall portion 23, thereby improving the rigidity in the vicinity of the lens holding portion 24. Since the lens 40 is held by the lens holding portion 24 having a high configuration, even when an external stress is applied to the housing 20, the deviation of the lens 40 in the optical axis 40 ax direction can be suppressed. Therefore, display defect of the display image 99 can be prevented and display quality can be maintained.

  In addition, in the present embodiment, the rigidity of the peripheral wall portion 23 is further enhanced by closing the opening of the peripheral wall portion 23 on the light source unit 30 side by the sub-substrate 33 of the light source unit 30. In addition, the rigidity of the peripheral wall portion 23 can also be improved by the rib 25 protruding radially inward from the peripheral wall portion 23. Therefore, since the lens 40 is held by the lens holding portion 24 provided on the peripheral wall portion 23 with further increased rigidity, even when a stress is applied to the housing 20 from the outside, the lens 40 is in the direction of the optical axis 40ax. The deviation is surely suppressed. In addition, since the rib 25 and the lens holding portion 24 that hold the liquid crystal panel 51 and the lens 40 are held by the same peripheral wall portion 23, variations in the optical axis 40ax direction of the lens 40 with respect to the liquid crystal panel 51 are suppressed. Therefore, the light beam refracted by the lens 40 can pass through a predetermined position of the liquid crystal panel 51. As a result, the margin of the liquid crystal panel 51 is not required, so that a transmissive display panel having a minimum size can be selected, and the head-up display device 100 can be reduced in size.

  Furthermore, in the present embodiment, the lens holding portion 24 and the side wall portion 22 are provided in the same housing 20, so that the light emitting diode can be obtained by reducing the variation in the optical axis 40 ax of the lens 40 with respect to the reflecting mirror portion 60. The light beam emitted from 31 is allowed to reach a predetermined position of the reflecting mirror unit 60. For example, in the reflecting mirror section 60 having a plurality of reflecting mirrors 61 and 66, the concave mirror 66 located on the far side from the lens 40 exhibits a remarkable effect of reducing variation in the optical axis 40ax direction of the lens 40, so that the margin allowance is provided. By downsizing, the size can be greatly reduced. In addition, the curved concave mirror 66 is larger in the thickness direction than the plane mirror 61 and occupies a large space in the head-up display device 100. Therefore, the reduction of the margin of the concave mirror 66 by exerting the effect of reducing the variation in the optical axis 40ax direction of the lens 40 significantly contributes to the miniaturization of the head-up display device 100. Therefore, the present invention is particularly suitable for the head head-up display device 100 including the reflecting mirror unit 60 including a plurality of reflecting mirrors and having the concave mirror 66.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, this invention is limited to the said embodiment and is not interpreted and can be applied to various embodiment in the range which does not deviate from the summary.

  In the above embodiment, the lens holding unit 24 that holds the lens 40 also serves as the light source holding unit that holds the light source unit 30. However, as shown in FIG. 6, the housing 120 may have the light source holding part 126 separately from the lens holding part 24. The light source holding part 126 is provided on the peripheral wall part 123. In this case, as shown in FIG. 5, the lens 140 is fastened and held to the lens holding portion 24 by a screw 149. As shown in FIG. 6, the light source unit 130 is fastened and held by the screw 39 to the light source holding unit 126.

  In the above embodiment, the liquid crystal panel 51 is attached to the side surface 25 c of the rib 25 by the double-sided tape 53. However, the attachment method of the liquid crystal panel 51 is not limited to the double-sided tape 53. As shown in FIG. 5, a rubber packing 153 is attached to the outer edge portion of the liquid crystal panel 51, and an urging portion 148 is formed on the exit surface 42 side of the lens 140. The liquid crystal panel 51 may be held by attaching the lens 140 to the lens holding portion 24 and urging the rubber packing 153 against the side surface 25 c of the rib 25 by the urging portion 148.

  In the above-described embodiment, the adjustment unit is provided in the attachment unit 44 of the lens 40, so that the position of the lens 40 can be adjusted in a direction orthogonal to the optical axis 40ax. However, the adjustment unit may not be provided in the lens 40. Or the structure adjusted so that the light emitting diode 31 may be located on the optical axis 40ax by providing the light source part 30 with the adjustment part to the direction orthogonal to the optical axis 40ax may be sufficient.

  In the above-described embodiment, the lens 40 and the light source unit 30 are provided with a positioning mechanism, and the position of the lens 40 with respect to the light source unit 30 is automatically adjusted by attaching the lens 40 and the light source unit 30 to the housing 20. However, the position adjustment mechanism may not be provided and the position adjustment of the optical axis 40ax of the lens 40 with respect to the light source unit 30 may be performed by an operator.

  In the above embodiment, the peripheral wall portion 23 has an annular shape that surrounds the outer side in the radial direction of the lens 40. However, the peripheral wall portion 23 may not be annular, and the peripheral wall portion 23 may not be provided. Furthermore, you may add the other structure which reduces the stress from the outside, for example, the outer shell member which covers the exterior of the housing 20.

  In the above embodiment, the reflecting mirror unit 60 is constituted by the plane mirror 61 and the concave mirror 66. However, the reflecting mirror unit 60 may be either the plane mirror 61 or the concave mirror 66, and may include a plurality of plane mirrors 61. Further, the flat mirror 61 is held on the side wall portion 22 of the housing 20 by the double-sided tape 63. However, as shown in FIG. 5, the housing 120 may be provided with a holding groove 128 along the shape of the plane mirror 61 and a plurality of protrusions 128 a in the holding groove 128. The “third holding portion” according to the claims may be configured such that the holding groove 128 and the projecting portion 128 a hold the lower end of the plane mirror 61 and the metal clip 163 holds the upper end of the plane mirror 61.

  In the above embodiment, the number of light emitting diodes 31 mounted on the sub-board 33 is one. However, as shown in FIG. 5, a plurality of light emitting diodes 31 may be mounted on the sub-substrate 133. In this case, the position of the optical axis 40ax of the lens 140 is adjusted so as to pass through the centroid with the positions of the plurality of light emitting diodes 31 as vertices.

  In the above-described embodiment, the example in which the present invention is applied to the head-up display device 100 that projects the display image 99 that is a virtual image on the windshield 91 of the vehicle has been described. The present invention can be applied to a head-up display device that projects a display image on a translucent projection member provided in front of a person.

It is a mimetic diagram showing composition of vehicles carrying a head up display device by one embodiment of the present invention. It is a top view which shows schematic structure of the head-up display apparatus by one Embodiment of this invention. FIG. 3 is a schematic diagram for explaining a characteristic part of the head-up display device according to the embodiment of the present invention, and is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a schematic diagram for explaining a characteristic part of the head-up display device according to the embodiment of the present invention, and is a view as seen from IV in FIG. 2. It is a schematic diagram for demonstrating another modification of the characteristic part of FIG. It is a schematic diagram for demonstrating another modification of the characteristic part of FIG.

Explanation of symbols

20, 120 Housing, 21 Bottom wall part, 22 Side wall part (third holding part), 23, 123 Peripheral wall part, 24 Lens holding part (second holding part, first holding part), 25 Rib (fourth holding part) , 25a Transmission window, 126 Light source holding part (first holding part), 27 Dust-proof cover, 128 Holding groove, 128a Projection part, 30, 130 Light source part, 31 Light emitting diode, 33, 133 Sub-board, 34 Fastening hole, 36 Positioning Hole (positioning mechanism), 39 Screw (fastening member), 40,140 lens, 40ax optical axis, 42 exit surface, 43 entrance surface, 44,144 mounting portion (adjusting portion), 44a plane, 44b mounting hole, 46 positioning pin (Positioning mechanism), 148 biasing part, 149 screw, 51 liquid crystal panel (transmission type liquid crystal panel), 53 double-sided tape, 153 rubber packing, 0 reflecting mirror part, 61 plane mirror, 61a reflecting surface, 163 double-sided tape, 163 metal clip, 66 concave mirror, 66a concave mirror surface, 73 main board, 79 screw, 91 windshield (projection member), 93 instrument panel, 99 display Image, 99a projection image, 99b projection virtual image, 100 head-up display device

Claims (11)

A head-up display device that projects a display image on a projection member,
A light source unit that emits a light beam for emitting the display image;
A lens that refracts the light beam from the light source section toward the optical axis;
A reflecting mirror part that reflects the light beam refracted by the lens toward the projection member;
A head-up display device comprising: a first holding part that holds the light source part; a second holding part that holds the lens; and a third holding part that holds the reflecting mirror part.   The head-up display device according to claim 1, wherein the second holding unit also serves as the first holding unit.   3. The head-up display device according to claim 1, wherein the lens includes an adjustment unit that is positionally adjustable with respect to the housing in a direction orthogonal to the optical axis. The adjustment portion has a mounting portion having a plane orthogonal to the optical axis, and a mounting hole provided in the mounting portion in a direction along the optical axis,
The head-up display device according to claim 3, wherein the lens is attached to the second holding portion by a fastening member that is loosely fitted into the attachment hole.   5. The positioning mechanism for positioning the lens unit in the direction perpendicular to the optical axis with respect to the light source unit is provided in the light source unit and the lens. The head-up display device described.   The positioning mechanism includes a positioning pin provided in the lens and projecting from the lens to the light source unit, and a positioning hole provided in the light source unit and fitted with the positioning pin. The head-up display device described in 1. The housing has a peripheral wall portion that annularly surrounds a radially outer side of the lens,
The head-up display device according to claim 1, wherein the second holding portion is provided on the peripheral wall portion.   The head-up display device according to claim 7, wherein an opening on the light source part side of the peripheral wall part is closed by the light source part. A transmissive display panel is provided on the reflecting mirror portion side of the lens in a direction orthogonal to the optical axis,
9. The head-up display device according to claim 7, wherein the housing has a fourth holding portion that protrudes radially inward from the peripheral wall portion and holds the transmissive display panel.   The head-up display device according to claim 1, wherein the reflecting mirror unit includes a plurality of reflecting mirrors.   The head-up display device according to claim 1, wherein the reflecting mirror unit includes a concave mirror.

Images