Image Projection Device

Abstract

To provide an image projection device with which it is possible to maintain high freedom of design even when different regions of a display unit are irradiated with a plurality of images, and reduce the number of emission planes of a light-emitting element that are needed for suppressing luminance unevenness.SOLUTION: The image projection device comprises an image display unit that displays a projection image, a light irradiation unit that irradiates the image display unit with irradiation light, and an irradiation optical unit that irradiates irradiation light as a projection image in the viewpoint direction via the display unit. The projection image includes a first and a second image that are projected to different regions of the display unit. The image display unit is provided with a first region (17b) that displays the first image, and a second region (17a) that displays the second image. The light irradiation unit has first light source units (12b, 13b) that irradiate the first region (17b) with light, and second light source units (12a, 13a) that irradiate the second region (17a) with light, the first light source units (12b, 13b) and the second light source units (12a, 13a) being arranged such that their longitudinal directions are inclined by an angle θ with respect to each other.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image projection device, and more particularly to an image projection device that reflects light emitted from an image projection unit to reach a viewpoint. [Background technology]

[0002] Conventionally, dashboards that illuminate icons have been used to display various types of information inside vehicles. As the amount of information to be displayed increases, it has been proposed to embed an image display device in the dashboard or to configure the entire dashboard with an image display device.

[0003] However, because the instrument panel is located below the vehicle's windshield, passengers such as the driver must undesirably move their eyes downward while driving to view the information displayed on the instrument panel. Therefore, image projection devices such as head-up displays (hereinafter referred to as HUDs) have been proposed that project images onto the windshield so that passengers can read information when they view the area ahead of the vehicle (see, for example, Patent Documents 1 and 2).

[0004] In conventional image projection devices, an image projection unit emits light containing an image, and the light is reflected by a free-form mirror or the like, and the light reaches the viewpoint of the occupant so that the image is formed in space via a display unit such as a windshield. This allows the occupant to perceive the image as being displayed at the imaging position in the depth direction due to the light incident at the viewpoint.

[0005] In addition, in order to present more information, it has been proposed to project multiple images onto the windshield using a driving assistance HUD device. However, in order to project and form multiple images as virtual images at different distances, multiple image projection units and projection optical systems are required, which has the problem of limited design flexibility when accommodating them within an instrument panel. Therefore, the applicant of the present application has proposed an image projection device that saves space by displaying multiple images within a single image projection unit and branching the optical paths of each image using an optical branching unit such as a prism. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-119248 [Patent Document 2] Japanese Patent Application Publication No. 2019-119262 Summary of the Invention [Problem to be solved by the invention]

[0007] When projecting multiple images at different distances, the images are projected onto different areas of the windshield surface, so the projected virtual image is affected by the surface shape of the windshield and the curvature of the free-form mirror. Typically, the windshield is curved near the bottom edge and is formed almost symmetrically in the left-right direction of the vehicle. Furthermore, since the occupants sit in the driver's seat or passenger seat of the vehicle, projecting an image toward them requires irradiating the light onto either the left or right side of the windshield. This has led to the problem of different distortions between the image reflected near the bottom edge of the windshield and the image reflected in the central area.

[0008] Furthermore, when a direct-type backlight liquid crystal display element in which the light-emitting surfaces of light-emitting elements are arranged on the back side of the display surface is used as the image irradiation section, the visibility of the projected image can be improved, but there is a problem in that the light-emitting surface of the light-emitting elements required to suppress uneven brightness of the image increases.

[0009] Therefore, the present invention has been made in consideration of the above-mentioned conventional problems, and aims to provide an image projection device that maintains a high degree of design freedom even when projecting multiple images onto different areas of the display unit, and that can reduce the number of light-emitting surfaces of the light-emitting elements required to suppress brightness unevenness. [Means for solving the problem]

[0010] In order to solve the above problem, an image projection device of the present invention is an image projection device that projects a projection image onto a display unit for displaying a virtual image, and includes: an image display unit that displays the projection image; a light irradiation unit that irradiates the image display unit with irradiation light; and an irradiation optical unit that irradiates the irradiation light as the projection image in a viewing direction via the display unit, wherein the projection image includes a first image and a second image that are projected onto different regions of the display unit, and the image display unit includes a first region that displays the first image and a second region that displays the second image, The longitudinal direction of the first region and the longitudinal direction of the second region are provided so as to be inclined relative to each other, The light irradiating unit has a first light source unit that irradiates the first region with light and a second light source unit that irradiates the second region with light, and a longitudinal direction of the first light source unit and a longitudinal direction of the second light source unit are 、 They are arranged at an angle of θ to each other. and irradiating the light in accordance with the relative inclination of the first region and the second region. It is characterized by:

[0011] In the image projection device of the present invention, the light irradiation unit includes a first light source unit and a second light source unit, and the longitudinal directions of the first light source unit and the second light source unit are tilted at an angle θ, so that light can be appropriately irradiated onto the first region and the second region. This makes it possible to maintain a high degree of design freedom even when irradiating multiple images onto different regions of the display unit, and to reduce the number of light-emitting surfaces of the light-emitting elements required to suppress brightness unevenness.

[0012] In one aspect of the present invention, the first light source section is arranged along the longitudinal direction of the first region, and the second light source section is arranged along the longitudinal direction of the second region.

[0013] In one aspect of the present invention, the first light source section and the second light source section each have a plurality of light-emitting elements whose light-emitting surfaces are arranged in an array.

[0014] In one aspect of the present invention, the light source device includes a first lens unit arranged between the first light source unit and the first region and aligned along the longitudinal direction of the first light source unit, and a second lens unit arranged between the second light source unit and the second region and aligned along the longitudinal direction of the second light source unit.

[0015] In addition, in one embodiment of the present invention, the first lens portion and / or the second lens portion have a shape in which a refractive portion located in the center and reflective portions located on both sides of the refractive portion are extended in a predetermined direction.

[0016] In one aspect of the present invention, the angle θ is in the range of 0.28 to 45 degrees.

[0017] In one aspect of the present invention, the virtual image of the first image and the virtual image of the second image are formed at different image positions. [Effects of the Invention]

[0018] The present invention provides an image projection device that maintains high design freedom even when projecting multiple images onto different areas of the display unit, and can reduce the number of light-emitting surfaces of the light-emitting elements required to suppress brightness unevenness. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic diagram showing the configuration of an image projection device according to a first embodiment. [Figure 2] 2 is a schematic cross-sectional view showing an example of the structure of the image projection unit 10. FIG. [Figure 3] 3A and 3B are schematic plan views showing examples of the structure of the image projection unit 10, where FIG. 3A shows the structure of the light source unit and FIG. 3B shows the structure of the image display unit. [Figure 4]These are photographs showing the imaging state of the virtual image 40, where FIG. 4(a) shows the case where the first light source unit and the second light source unit are arranged parallel to each other, and FIG. 4(b) shows the case where the first light source unit and the second light source unit are arranged tilted by an angle θ. [Figure 5] 10 is a schematic plan view showing an example of the structure of a light source section according to a second embodiment. FIG. [Figure 6] FIG. 10 is a schematic plan view showing an example of the structure of a light source section according to a third embodiment. [Figure 7] 7A and 7B are schematic plan views showing examples of the structure of a light source unit according to a third embodiment, in which FIG. 7A shows an example in which multiple light-emitting surfaces of light-emitting elements are arranged in a staggered pattern, and FIG. 7B shows an example in which multiple light-emitting surfaces of light-emitting elements are arranged in a staggered pattern along a curve. DETAILED DESCRIPTION OF THE INVENTION

[0020] (First embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing will be given the same reference numerals, and redundant explanations will be omitted where appropriate. Figure 1 is a schematic diagram showing the configuration of an image projection device according to this embodiment.

[0021] As shown in Fig. 1, the image projection device includes an image projection unit 10 and an projection optical unit 20. The image projection device also includes a control unit (not shown) that is connected to each unit so as to be able to communicate information with each unit and controls each unit. The configuration of the control unit is not limited, but examples include a control unit that includes a CPU (Central Processing Unit) for information processing, a memory device, a recording medium, an information communication device, etc. The control unit controls the operation of each unit in accordance with a predetermined program, and sends information including an image (image information) to the image projection unit 10.

[0022] The image projection unit 10 is a device that projects illumination light (image light) containing image information when a signal containing image information of a projection image is supplied from an information processing unit (not shown). Here, the projection image includes a first image and a second image projected through different areas of the windshield 30. The illumination light projected from the image projection unit 10 enters the illumination optical unit 20. The image projection unit 10 can also use a liquid crystal display device that projects light from a light source unit (backlight) onto the projection image displayed on the image display unit.

[0023] The illumination optical unit 20 is an optical system component that projects illumination light containing image information emitted from the image illumination unit 10 through the windshield 30 in the direction of the viewpoint as a projected image. In the example shown in FIG. 1 , the illumination optical unit 20 includes a free-form surface mirror 21, a free-form surface mirror 22, a light branching unit 23, and a free-form surface mirror 24. The combination of the free-form surface mirror 21 and the free-form surface mirror 22, and the combination of the light branching unit 23, the free-form surface mirror 24, and the free-form surface mirror 22 constitute the first optical unit and the second optical unit, respectively. Convex or concave lenses may be disposed in the first or second optical unit as needed to expand or reduce the light diameter. The arrangement and orientation of the free-form surface mirror 21, the free-form surface mirror 22, the light branching unit 23, and the free-form surface mirror 24 are not limited to those shown in FIG. 1 .

[0024] The windshield 30 is a part provided in front of the driver's seat of the vehicle that transmits visible light. The windshield 30 corresponds to the display unit of the present invention because, on the inside surface of the vehicle, it reflects the first image light and the second image light incident from the free-form surface mirror 22 toward the viewpoint and transmits light from outside the vehicle toward the viewpoint. While an example in which the windshield 30 is used as the display unit has been shown here, a combiner may be provided as a display unit separate from the windshield 30 and reflect light from the free-form surface mirror 22 toward the viewpoint. Furthermore, the display unit is not limited to being located at the front of the vehicle, and may be located to the side or rear as long as it projects an image toward the viewpoint of the passenger.

[0025] The virtual images 40 and 50 are images that are displayed as if they were formed in space when the first image light and the second image light reflected by the windshield 30 reach the viewpoint (eyebox) of a passenger or the like. The positions at which the virtual images 40 and 50 are formed are determined by the angle of spread of the light irradiated from the image irradiator 10 as it travels toward the viewpoint after being reflected by the free-form surface mirror 21, the free-form surface mirrors 22 and 24, and the windshield. The virtual images 40 and 50 in the example shown in FIG. 1 correspond to the first image and the second image, respectively, in the present invention.

[0026] The free-form surface mirror 21 is an optical member onto which the first image light irradiated from the image projection unit 10 is incident and which reflects the first image light toward the free-form surface mirror 22. In the example shown in FIG. 1, a convex mirror is shown as the free-form surface mirror 21, but a mirror with an optical design necessary for projecting the first image light as a virtual image can be used, and a concave mirror, a plane mirror, a free-form surface mirror, or the like can be used as needed. Furthermore, the free-form surface mirror 21 may be omitted, and the first image light from the image projection unit 10 may be directly incident on the free-form surface mirror 22.

[0027] The free-form surface mirror 22 is a concave mirror that receives the first image light reflected by the free-form surface mirror 21 and the second image light reflected by the free-form surface mirror 24 and reflects the first image light and the second image light toward the windshield 30. The reflective surface of the free-form surface mirror 22 is designed to expand the light diameter toward the viewpoint of the passenger in order to project a virtual image through the windshield 30. Here, the expansion of the light diameter toward the viewpoint includes not only the case where the light diameter consistently expands after reflection, but also the case where the light diameter shrinks and expands after forming an image at an intermediate point.

[0028] The light branching unit 23 is an optical element that branches the light of the image irradiated from the image projection unit 10, and branches at least the irradiation light that forms the virtual image 40 as the first image light and the irradiation light that forms the virtual image 50 as the second image light. The structure of the light branching unit 23 is not limited as long as it is an optical element that branches light, and a prism may be used, or a method such as using a reflecting mirror to change the angle of incidence and the angle of reflection of light may be used. In the example shown in FIG. 1 , a prism is used as the light branching unit 23, and the prism is arranged overlapping a part of the image projection unit 10.

[0029] Here, arranging the light branching unit 23 so as to overlap the image projection unit 10 means that the area in which the light branching unit 23 is arranged overlaps with the image display area of ​​the image projection unit 10 in a planar view. The overlapping arrangement also includes cases where the light branching unit 23 and the image projection unit 10 are in contact with each other and cases where they are not in contact with each other. The overlapping arrangement also includes cases where an optical member that transmits light or a holding member that maintains the distance between the light branching unit 23 and the image projection unit 10 is interposed between the light branching unit 23 and the image projection unit 10.

[0030] The free-form surface mirror 24 is an optical element onto which the second image light branched by the optical branching unit 23 is incident and which reflects the second image light in the direction of the free-form surface mirror 22. In the example shown in Fig. 1, a concave mirror is shown as the free-form surface mirror 24, but any mirror with an optical design necessary to project the second image light as a virtual image can be used, and a convex mirror, a plane mirror, a free-form surface mirror, or the like can be used as needed.

[0031] As shown in Fig. 1, in the image projection device of this embodiment, illumination light emitted from image illumination unit 10 is split into first image light and second image light by optical splitter 23. The dashed and dotted lines in Fig. 1 schematically show the optical paths of the first image light and the second image light, respectively. The dashed and dotted lines in Fig. 1 also show extensions of the first image light and the second image light in the direction of incidence from the viewpoint position of the passenger.

[0032] The first image light incident on the free-form surface mirror 21 is reflected by the free-form surface mirror 22 and the windshield 30 and reaches the viewpoint. At this time, the occupant visually recognizes a virtual image 40 formed outside the windshield 30 on an extension of the incident direction of the first image light. The second image light branched by the light branching unit 23 is reflected by the free-form surface mirror 24, the free-form surface mirror 22, and the windshield 30 and reaches the viewpoint. At this time, the occupant visually recognizes a virtual image 50 formed outside the windshield 30 on an extension of the incident direction of the second image light.

[0033] 1, the first image light is irradiated near the bottom edge of the windshield 30, and the second image light is irradiated near the center of the windshield 30. Furthermore, the first and second image lights reach the viewpoint after their light diameters are expanded by the first and second optical units, respectively, so that the passenger visually perceives the first and second virtual images formed by the first and second image lights as if they were formed at a predetermined distance. Here, the positions at which the virtual images 40 and 50 are formed are such that the virtual image 40 is closer to the viewpoint than the virtual image 50.

[0034] 2 is a schematic cross-sectional view showing an example of the structure of the image projection unit 10. As shown in FIG. 2, the image projection unit 10 includes a substrate 11, light-emitting surfaces 12a and 12b of the light-emitting elements, lens units 13a and 13b, a common lens 14, a light-shielding plate 15, a diffusion plate 16, and an image display unit 17.

[0035] The substrate 11 is a substantially plate-shaped member that mounts and holds the light-emitting surfaces 12a, 12b of the light-emitting elements. Although not shown in FIG. 1, a wiring pattern is formed on the surface of the substrate 11, and the light-emitting surfaces 12a, 12b of the multiple light-emitting elements are electrically connected to the wiring pattern. A drive circuit that supplies current to the light-emitting surfaces 12a, 12b of the light-emitting elements to drive and control light emission may also be formed on the substrate 11. A control unit that controls each part of the image projection device may also be mounted on the substrate 11.

[0036] The light-emitting surfaces 12a and 12b of the light-emitting elements are light-emitting surfaces of electronic components mounted on the substrate 11 and emitting irradiated light. Here, the light-emitting surfaces 12a and 12b of the light-emitting elements refer to the light-emitting portions of the light-emitting electronic components, and do not necessarily coincide with the positions of the electronic components themselves. The specific configuration of the light-emitting surfaces 12a and 12b of the light-emitting elements is not limited, but it is preferable to use light-emitting surfaces of light-emitting diodes (LEDs). The light emitted by the light-emitting surfaces 12a and 12b of the light-emitting elements is preferably white, but light emitting surfaces emitting a single color such as blue, green, or red may also be used. The light-emitting surfaces 12a and 12b of the light-emitting elements are arranged in an array along the paper surface direction in FIG. 2, as will be described later.

[0037] Lens portions 13a and 13b are optical components into which light emitted from light-emitting surfaces 12a and 12b of the light-emitting elements enters through an incident portion, is refracted or reflected, and exits through an exit portion. In the example shown in Fig. 2, lens portions 13a and 13b are total internal reflection lenses (TIR lenses) having a refractive portion disposed in the center and reflecting portions disposed on both sides of the refractive portion. Furthermore, lens portions 13a and 13b have a shape that is elongated in the direction of the paper surface in Fig. 2, as will be described later, and their incident portions are disposed opposite light-emitting surfaces 12a and 12b of the light-emitting elements, following the arrangement of light-emitting surfaces 12a and 12b of the light-emitting elements.

[0038] Common lens 14 is an optical member that refracts light emitted from the emission portions of lens portions 13a and 13b and irradiates the light onto a predetermined area of ​​image display portion 17. There are no limitations on the structure of common lens 14, but it is preferable to expand and irradiate light in the left-right direction in FIG. 2, and a concave lens or a lenticular lens can be used.

[0039] 2, the combination of light-emitting surfaces 12a and 12b of the light-emitting elements, lens portions 13a and 13b, and common lens 14 constitutes a light irradiation portion that irradiates light onto image display portion 17. Furthermore, light-emitting surfaces 12a and 12b of the arrayed light-emitting elements correspond to the second light source portion and the first light source portion, respectively, of the present invention. Furthermore, lens portions 13a and 13b correspond to the second lens portion and the first lens portion, respectively, of the present invention.

[0040] The light-shielding plate 15 is disposed between the image display unit 17 and the light-emitting surfaces 12a and 12b of the light-emitting elements, and is a member that limits the area where light irradiated from the light-emitting surfaces 12a and 12b of the light-emitting elements is incident on the image display unit 17. As will be described later, the light-shielding plate 15 is provided with a light-transmitting portion for defining the first area and the second area, and the light-transmitting portion transmits light, while the other areas are formed using a light-shielding material and block light. Here, the light-transmitting portion may be an opening formed in the light-shielding plate 15, or may be a light-transmitting portion that is not provided with a light-shielding material.

[0041] The diffusion plate 16 is a member that diffuses or scatters light that has passed through the light-transmitting portion of the light-shielding plate 15. The material and structure that constitutes the diffusion plate 16 are not limited, and a plate- or film-shaped member made of a light-transmitting resin material with a roughened surface can be used. By using the diffusion plate 16, the directionality of the transmitted light can be reduced, thereby improving visibility.

[0042] Image display unit 17 is a part that displays a projection image in response to an image signal from the control unit. Light from light-emitting surfaces 12a and 12b of the light-emitting elements that serve as a backlight is irradiated onto the projection image displayed on image display unit 17, whereby first image light and second image light are irradiated from image irradiation unit 10. The specific configuration of image display unit 17 is not limited, but a transmissive liquid crystal display device or the like can be used.

[0043] FIG. 3 is a schematic plan view showing an example of the structure of the image projection unit 10, where FIG. 3(a) shows the structure of the light source unit and FIG. 3(b) shows the structure of the image display unit. As shown in FIG. 3(a), light-emitting surfaces 12a and 12b of a plurality of light-emitting elements are arranged in an array on a substrate 11. The dashed-dotted line shown in FIG. 3(a) is a line connecting the centers of the light-emitting surfaces 12a and 12b of the light-emitting elements and indicates the longitudinal direction of the arrangement of the light-emitting surfaces 12a and 12b of the light-emitting elements (the longitudinal direction of the second light source unit and the first light source unit). Furthermore, the lens units 13a and 13b are arranged along the longitudinal direction of the arrangement of the light-emitting surfaces 12a and 12b of the light-emitting elements. Furthermore, the longitudinal directions of the arrangement of the light-emitting surfaces 12a and 12b of the light-emitting elements are tilted from each other by an angle θ.

[0044] Here, the angle θ is preferably in the range of 0.28 to 45 degrees. If θ is less than 0.28 degrees, it becomes difficult to irradiate light in accordance with the inclination of the first and second regions, which will be described later. Also, if θ is greater than 45 degrees, the area of ​​the substrate 11 required to mount the light-emitting surfaces 12a and 12b of the light-emitting element becomes large, making it difficult to achieve miniaturization.

[0045] As shown in FIG. 3(b), the image display unit 17 has, within its display surface, a first region 17b that displays a first image and a second region 17a that displays a second image. In the example shown in FIG. 3(b), the first region 17b is shaped to compensate for distortions caused by the curvature of the irradiation optical unit 20 and the windshield 30. As shown in FIG. 1, the irradiation positions and angles of the first image light and the second image light within the windshield 30 are different, so the first region 17b and the second region 17a are also tilted from each other by an angle θ. Furthermore, the light shielding plate 15 is provided with light-transmitting portions 15b and 15a that encompass the first region 17b and the second region 17a, respectively.

[0046] As shown in FIGS. 2 and 3, the light-emitting surfaces 12b of the arrayed light-emitting elements constituting the first light source are arranged along the longitudinal direction of the first region 17b. The light-emitting surfaces 12a of the arrayed light-emitting elements constituting the second light source are arranged along the longitudinal direction of the second region 17a. Therefore, the light-emitting surfaces 12b and 12a of the light-emitting elements irradiate the first region 17b and the second region 17a, respectively. Here, the longitudinal direction of the first region 17b and the second region 17a refers to a tangent direction to the center line of each region or a linear direction approximating the center line. For example, the center line of the array of the light-emitting surfaces 12b of the light-emitting elements overlaps with an approximate line to the center line of the first region 17b.

[0047] Light emitted from light-emitting surfaces 12b of the arrayed light-emitting elements passes through lens section 13b, common lens 14, light-transmitting section 15b, and diffuser plate 16, and enters first region 17b. As a result, the first image displayed in first region 17b is irradiated as first image light from image irradiation section 10 onto free-form surface mirror 21, and is reflected by free-form surface mirror 22 and windshield 30 to form virtual image 40.

[0048] Furthermore, light emitted from light-emitting surfaces 12a of the arrayed light-emitting elements is transmitted through lens section 13a, common lens 14, light-transmitting section 15a, and diffuser plate 16, and is incident on second region 17a. As a result, the second image displayed on second region 17a is emitted from image irradiation section 10 as second image light, branched by light branching section 23, and reflected by free-form surface mirror 24, free-form surface mirror 22, and windshield 30 to form virtual image 50.

[0049] 4A and 4B are photographs showing the state of formation of virtual image 40. FIG. 4A shows the case where the first light source unit and the second light source unit are arranged parallel to each other, and FIG. 4B shows the case where the first light source unit and the second light source unit are arranged tilted by an angle θ. As shown in FIG. 4A, when the arrangement of light-emitting surfaces 12b of the light-emitting elements of the first light source unit is parallel to the arrangement of light-emitting surfaces 12a of the light-emitting elements of the second light source unit, the relative tilt between first region 17b and second region 17a does not match the arrangement of light-emitting surfaces 12b, 12a of the light-emitting elements, resulting in diagonal brightness unevenness in the formed virtual image 40. When light-emitting surfaces 12b of the light-emitting elements and light-emitting surfaces 12a of the light-emitting elements are arranged parallel to each other, it is necessary to arrange light-emitting surfaces 12b of the light-emitting elements in a multi-row array or matrix in order to reduce such brightness unevenness. This increases the number of elements required to suppress brightness unevenness.

[0050] 4(b), when the arrangement of light-emitting surfaces 12b of the light-emitting elements serving as the first light source is tilted by an angle θ relative to the arrangement of light-emitting surfaces 12a of the light-emitting elements serving as the second light source, the relative tilt of first region 17b and second region 17a matches the arrangement of light-emitting surfaces 12b, 12a of the light-emitting elements, resulting in a uniform image display without brightness unevenness in the formed virtual image 40. Therefore, even if the distortion-compensated first region 17b is tilted relative to the second region 17a, simply arranging the light-emitting surfaces 12b of the light-emitting elements in a single row array can reduce brightness unevenness and the number of elements required.

[0051] As described above, in the image projection device of this embodiment, the arrangement of light-emitting surfaces 12b, 12a of the light-emitting elements is tilted at angle θ to each other, thereby enabling appropriate light irradiation onto first region 17b and second region 17a. This allows a high degree of design freedom to be maintained even when multiple images are projected onto different regions of windshield 30, and makes it possible to reduce the number of light-emitting surfaces of the light-emitting elements required to suppress brightness unevenness.

[0052] (Second embodiment) Next, a second embodiment of the present invention will be described with reference to Fig. 5. Description of content that overlaps with the first embodiment will be omitted. Fig. 5 is a schematic plan view showing an example of the structure of a light source unit according to this embodiment. This embodiment differs from the first embodiment in that multiple lenses are used as lens units 13a and 13b.

[0053] As shown in Fig. 5, light-emitting surfaces 12a and 12b of a plurality of light-emitting elements are arranged in an array on substrate 11. Furthermore, the longitudinal directions of the arrangement of light-emitting surfaces 12a and 12b of the light-emitting elements are tilted at an angle θ from each other. Furthermore, lens portions 13a and 13b are configured by an arrangement of a plurality of individual lenses each having a circular shape in a plan view, and the center of each individual lens is arranged so as to overlap the center of light-emitting surfaces 12a and 12b of the light-emitting elements. Therefore, the line connecting the centers of the individual lenses is arranged along the longitudinal direction of the arrangement of light-emitting surfaces 12a and 12b of the light-emitting elements.

[0054] In this embodiment, too, the light-emitting surfaces 12b, 12a of the light-emitting elements are arranged at an angle θ to each other, thereby enabling appropriate light irradiation onto the first region 17b and the second region 17a. This maintains a high degree of design freedom even when projecting multiple images onto different regions of the windshield 30, and makes it possible to reduce the number of light-emitting surfaces of the light-emitting elements required to suppress brightness unevenness.

[0055] (Third embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. 6. Description of content that overlaps with the first embodiment will be omitted. FIG. 6 is a schematic plan view showing an example of the structure of a light source unit according to this embodiment. This embodiment differs from the first embodiment in that the arrangement of light-emitting surfaces 12b of the light-emitting elements and lens portions 13b are curved in plan view.

[0056] As shown in FIG. 6, light-emitting surfaces 12a and 12b of a plurality of light-emitting elements are arranged in an array on substrate 11. Furthermore, as indicated by the dashed-dotted line in the figure, the longitudinal direction connecting the centers of light-emitting surfaces 12b of the light-emitting elements is curved. The longitudinal direction of the arrangement of light-emitting surfaces 12b of the light-emitting elements is inclined by an angle θ with respect to the arrangement of light-emitting surfaces 12a of the light-emitting elements. Here, "the curved longitudinal direction is inclined by an angle θ" means that a straight line approximating the curved longitudinal direction or a tangent to the longitudinal direction, specifically a tangent to the center of light-emitting surfaces 12b of the plurality of light-emitting elements, is inclined by an angle θ with respect to the longitudinal direction of the arrangement of light-emitting surfaces 12a of the light-emitting elements. Similarly, the longitudinal direction of lens portion 13b is inclined by an angle θ with respect to the longitudinal direction of lens portion 13a.

[0057] The arrangement of light-emitting surfaces 12b of the light-emitting elements and the center line of lens portions 13b shown in Fig. 6 preferably substantially coincide with the center line of first region 17b shown in Fig. 3(b). By substantially coinciding the center lines of light-emitting surfaces 12b of the light-emitting elements, lens portions 13b, and first region 17b, light emitted from light-emitting surfaces 12b of the light-emitting elements is more uniformly irradiated onto first region 17b, and brightness unevenness can be suppressed while reducing the number of elements on light-emitting surface 12b of the light-emitting elements.

[0058] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. 7. Description of content overlapping with the first embodiment will be omitted. FIG. 7 is a schematic plan view showing an example of the structure of a light source unit according to this embodiment, where FIG. 7(a) shows an example in which the light-emitting surfaces of a plurality of light-emitting elements are arranged in a staggered pattern, and FIG. 7(b) shows an example in which the light-emitting surfaces of a plurality of light-emitting elements are arranged in a staggered pattern along a curve. As shown in FIGS. 7(a) and 7(b), in this embodiment, the light-emitting surfaces 12a and 12b of a plurality of light-emitting elements are arranged in a staggered pattern to form light-emitting element groups 25a, 25b, and 26b, which correspond to the second light source unit and the first light source unit of the present invention.

[0059] Each of the light-emitting element groups 25a, 25b, and 26b is a region connecting the peripheries of the light-emitting surfaces 12a and 12b of the plurality of light-emitting elements included therein. In the example shown in Fig. 7(a), this region is approximately rectangular, while in the example shown in Fig. 7(b), this region is fan-shaped, sandwiched between two arcs. Each of the light-emitting element groups 25a, 25b, and 26b includes the light-emitting surfaces 12a and 12b of the plurality of light-emitting elements. In the examples shown in Figs. 7(a) and 7(b), the light-emitting surfaces 12a and 12b of the light-emitting elements are alternately arranged in a staggered pattern along the longitudinal center line of each of the light-emitting element groups 25a, 25b, and 26b. The center lines of the light-emitting element groups 25a, 25b, and 26b are approximately aligned with the center lines of the lens portions 13a and 13b, respectively.

[0060] In this embodiment, too, the center line of the light-emitting element group 25a is approximately aligned with the center lines of the lens portion 13b and the first region 17b, so that the light irradiated from the light-emitting surface 12b of the light-emitting element is irradiated more uniformly onto the first region 17b, and brightness unevenness can be suppressed while reducing the number of elements on the light-emitting surface 12b of the light-emitting element.

[0061] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0062] 10...Image irradiation unit 20...Irradiation optical section 30...Windshield 40,50...Virtual image 11... Circuit board 12a, 12b...light-emitting surfaces of light-emitting elements 13a, 13b...Lens section 14...Common lens 15...Light shield 15a, 15b...light transmitting part 16...Diffuser 17...Image display section 17a…Second area 17b…First area 21, 22, 24...Free-form mirrors 23...Optical branching section 25a, 25b, 26b... light emitting element groups

Claims

1. An image projection device that projects a projection image onto a display unit for displaying a virtual image, an image display unit that displays the projected image; a light irradiation unit that irradiates the image display unit with irradiation light; an illumination optical unit that illuminates the illumination light in a viewing direction as the projected image via the display unit, the projected image includes a first image and a second image projected onto different regions of the display unit; the image display unit includes a first area for displaying the first image and a second area for displaying the second image; The longitudinal direction of the first region and the longitudinal direction of the second region are provided so as to be inclined relative to each other, the light irradiating unit includes a first light source unit that irradiates the first region with light and a second light source unit that irradiates the second region with light, The longitudinal direction of the first light source unit and the longitudinal direction of the second light source unit are arranged at an angle θ to each other, and light is irradiated in accordance with the relative inclination of the first area and the second area.

2. 2. The image projection device according to claim 1, the first light source unit is disposed along the longitudinal direction of the first region, The image projection device, wherein the second light source unit is arranged along the longitudinal direction of the second area.

3. 3. The image projection device according to claim 1, The image projection device, wherein the first light source unit and the second light source unit each have a plurality of light-emitting elements with light-emitting surfaces arranged in an array.

4. 4. The image projection device according to claim 1, a first lens portion disposed between the first light source portion and the first region and extending in a longitudinal direction of the first light source portion; an image projection device comprising: a second lens portion disposed between the second light source portion and the second region and extending along a longitudinal direction of the second light source portion;

5. 5. The image projection device according to claim 4, An image projection device characterized in that the first lens unit and / or the second lens unit have a shape in which a refractive unit located in the center and reflective units located on both sides of the refractive unit are extended in a predetermined direction.

6. 6. The image projection device according to claim 1, The image projection device is characterized in that the angle θ is in the range of 0.28 to 45 degrees.

7. 7. The image projection device according to claim 1, An image projection device, characterized in that the virtual image of the first image and the virtual image of the second image are formed at different image positions.

Images