Image projection device

Abstract

The present invention provides an image projection device that can project images with a well-balanced shape, both in parts close to the vehicle body and parts far from it. [Solution] The image projection apparatus 1 of the present invention comprises a plurality of light sources 2, a plurality of lenses 4 facing each of the plurality of light sources 2, and a plate-shaped shade 3 interposed between the light sources 2 and the lenses 4. The shade 3 is provided with a plurality of openings 31 that allow the light L from the plurality of light sources 2 to pass towards the plurality of lenses 4. The openings are formed in a trapezoidal shape.

Description

Technical Field

[0001] The present invention relates to an image projection device for vehicles that projects a predetermined image onto a road surface.

Background Art

[0002] Conventionally, in vehicle lamps, there is a known technology that projects an image onto a road surface to attract the attention of surrounding vehicles and pedestrians or assist the driver in driving. For example, Patent Document 1 proposes an invention of a start notification display device that optically draws a start notification display of a predetermined shape on the road surface in the vehicle traveling direction and accurately enables pedestrians and the like to grasp the timing of the vehicle's start.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when an image is projected onto a road surface using an image projection device, since light is projected obliquely upward from the vehicle body toward the road surface, there is a problem that the width extends as the distance from the vehicle body increases, and a desired image cannot be drawn.

[0005] Therefore, an object of the present invention is to provide an image projection device that can project an image in a well-balanced shape for both the part close to the vehicle body and the part far from the vehicle body among the projected images.

Means for Solving the Problems

[0006] To solve the above problems, the present invention provides an image projection device for a vehicle, comprising a plurality of light sources, a plurality of lenses facing each of the plurality of light sources, and a plate-shaped shade interposed between the light sources and the lenses, wherein the shade has a plurality of openings that allow the light from the plurality of light sources to pass towards the plurality of lenses, and the openings are arranged in a trapezoidal shape.

[0007] The openings are preferably shaped like trapezoids, with the lower base being shorter than the upper base, and arranged in a series.

[0008] It is also possible to provide three or more openings in the shade, with the distances between the openings varying.

[0009] Multiple openings can be provided, each of a different size. [Effects of the Invention]

[0010] According to the image projection device of the present invention, a shade is interposed between the light source and the lens, and an opening is provided in the shade to allow light from the light source to pass through. Since the opening is in a trapezoidal shape, by adjusting the length of the upper and lower bases of the trapezoidal shape, it is possible to project a well-balanced shape onto both the part of the vehicle close to the vehicle and the part of the vehicle far from the vehicle, with a simple configuration. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of the image projection device of Embodiment 1 of the present invention. [Figure 2] Figure 1 is a schematic exploded perspective view of the image projection device. [Figure 3] Figure 1 is a schematic diagram showing the positional relationship between the image projection device and obstacles, as well as the light distribution state. [Figure 4] Figure 1 is a schematic diagram showing the image projection device installed alongside the backup lamp. [Figure 5] Figure 1 is a schematic diagram showing the image projected by the image projection device. [Figure 6]The schematic diagram shows the image projection device according to the modification example installed in the headlamp chamber. [Figure 7] It is a schematic diagram showing the arrangement and orientation of the lenses of the image projection device in FIG. 6, (a) a schematic AA cross-sectional view of the lens portion, and (b) a schematic diagram showing the inclination state of the lens. [Figure 8] It is a schematic diagram showing the image projected by the image projection device in FIG. 6. [Figure 9] It is a schematic diagram of the image projection device according to Example 2 of the present invention. [Figure 10] It is a schematic exploded perspective view of the image projection device. [Figure 11] It is a schematic diagram showing the projection state of the image projection device on the road surface. [Figure 12] It is a schematic diagram showing the arrangement state of the image projection device. [Figure 13] It is a schematic diagram showing the image projected by the image projection device installed side by side with the backup lamp. [Figure 14] It is a schematic diagram showing the image projected by the image projection device. (a) shows the case of a side turn signal lamp, and (b) shows the case of a headlamp. [Figure 15] It is a schematic diagram of the image projection device according to Example 3 of the present invention. [Figure 16] It is a schematic exploded perspective view of the image projection device in FIG. 15. [Figure 17] It is a schematic diagram showing the optical axis, light beam, and projection image by the image projection device in FIG. 15, (a) a schematic diagram seen from above, and (b) a schematic diagram seen from the side. [Figure 18] In the case where the focus is arranged inside the lens, (a) is a schematic AA cross-sectional view, and (b) is a schematic diagram of the shade seen from the front direction of the device. [Figure 19] In the case of FIG. 18, it is a schematic diagram showing (a) the projection image by a rectangular opening and (b) the projection image by a trapezoidal opening. [Figure 20] In the case where the focus is not arranged inside the lens, (a) is a schematic AA cross-sectional view, and (b) is a schematic diagram of the shade seen from the front direction of the device. [Figure 21]In the case of FIG. 20, it is a schematic diagram showing (a) a projected image by a rectangular opening and (b) a projected image by a trapezoidal opening. [Figure 22] It is a plan schematic diagram showing the image projection apparatus and the projected image of FIG. 15. [Figure 23] It is a schematic diagram showing a state where the image projection apparatus according to the modification is provided in the lamp chamber of the headlamp. [Figure 24] It is (a) a schematic cross-sectional view of the BB cross-section of the lens part and (b) a schematic diagram of the inclination state of each lens as viewed from the side, showing the lens arrangement and lens orientation of the image projection apparatus of FIG. 23. [Figure 25] It is (a) a schematic diagram of the shade of the image projection apparatus of FIG. 23 as viewed from the front direction of the apparatus and (b) an enlarged view of the opening. [Figure 26] It is a plan schematic diagram showing the image projection apparatus and the projected image of FIG. 23.

Mode for Carrying Out the Invention

Example

[0012] Hereinafter, Example 1 in which the present invention is embodied in an image projection apparatus will be described based on the drawings. The image projection apparatus 1 shown in FIGS. 1 and 2 includes a plurality of light sources 2 (2c, 2b, 2a) that irradiate light L (Lc, Lb, La) for projecting an image G (Gc, Gb, Ga), and a plurality of lenses 4 (4c, 4b, 4a) facing the plurality of light sources 2 respectively.

[0013] As shown in FIG. 2, the image projection apparatus 1 includes a substrate 7 on which the light source 2 is mounted, an attachment 5 for attaching the shade 3 to the substrate 7, a shade 3 that cuts the light L from the light source 2 into a shape corresponding to the image G, a lens 4 that transmits the light L from the light source 2, and an extension 6 that shields the internal structure of the image projection apparatus 1 from the outside of the vehicle.

[0014] Light sources 2c, 2b, and 2c are LEDs with the same luminous flux, that is, LEDs with the same current value and the same brightness, and are arranged vertically. Arranging the light sources vertically has the advantage of simplifying the optical design of the lens compared to arranging them horizontally.

[0015] Light source 2 is configured such that the light Lc, Lb, Lc emitted from light sources 2c, 2b, 2c descends towards the road surface at an inclined angle. By arranging light source 2 in this manner, images Gc, Gb, Gc extending in the vehicle-length direction can be projected onto the road surface.

[0016] Furthermore, the light source 2 is positioned on the same line as the image G drawn by the light L from the light source 2 (see Figures 5 and 8). By arranging the light source 2 and the image G in a straight line A, it becomes clearer that they are images belonging to the same function compared to when the light source 2 and the image G are projected scattered to the left and right. In this case, the vehicle lighting equipment (e.g., backup lamp 52) installed alongside the light source 2 may also be configured to be positioned on the same line as the light source 2 and the image G.

[0017] The shade 3 is provided with a trapezoidal opening 31 having an upper base 32 that is longer than the lower base 33. By appropriately adjusting the ratio of the upper base 32 to the lower base 33, the shape of the projected image G can be adjusted. For example, it is also possible to provide a rectangular opening 31 and project a trapezoidal image G that becomes wider as it moves away from the vehicle body 51.

[0018] In Example 1, the shade 3 has identical openings 31 in both shape and area. By making the area and shape of the openings 31 the same, the structure of the shade 3 can be simplified, and manufacturing costs can be reduced.

[0019] Multiple lenses 4 (4c, 4b, 4a) are integrally formed and configured to pass multiple light beams Lc, Lb, Lc( from multiple light sources 2c, 2b, 2c) through each of them. Each lens 4c, 4b, and 4a has a different diameter r (diameter rc < diameter rb < diameter ra), with the diameter r increasing towards the bottom. To prevent overlapping, the distance between lenses 4c, 4b, and 4a increases as the diameter r increases. Furthermore, the position of each lens 4 relative to the light source 2 is determined according to its own focal length.

[0020] Lens 2 with a larger diameter r is positioned to project image G at a position further away from the vehicle body 51 than lens 2 with a smaller diameter r. For example, lens 4b has a larger diameter r than lens 4c (diameter rb > diameter rc), and the image Gb projected by lens 4b is drawn at a position further away from the vehicle body 51 than the image Gc projected by lens 4c. Since the light beam passing through lens 4b with a larger diameter r is greater than the light beam passing through lens 4c with a smaller diameter r, image Gb, which is further away from the vehicle body 51, can be projected with the same illuminance as image Gc, which is closer to the vehicle body 51.

[0021] Lens 4 is positioned such that the optical axes of the light rays Lc, Lb, and Lc that pass through lenses 4c, 4b, and 4a are non-parallel to each other. The optical axes of the light rays Lc, Lb, and Lc intersect in a side view, and the images Gc, Gb, and Ga are projected in the order of light source 2c positioned above, light source 2b positioned in the middle, and light source 2a positioned below, moving away from the vehicle body 51. At this time, the tilt of lens 4 is set to be greater for lenses 4 that project closer to the vehicle projection device 1 or the vehicle body 51. By positioning lens 4 in this way, it is possible to project the images Gc, Gb, and Ga while avoiding obstacles such as the bumper 53, as shown in Figure 3(a). On the other hand, if there are no obstacles blocking the light rays L between the image projection device 1 and the road surface, it is also possible to arrange the lenses in the order of lens 4a, lens 4b, and lens 4c from top to bottom, as shown in Figure 3(b).

[0022] As shown in Fig. 4, the image projection device 1 is arranged in parallel with the backup lamp 52, and the emitted light L from the light source 2 is provided so as to be visually recognized integrally with the light L' from the backup lamp 52. In particular, it is desirable that the distance d between the light source 2 and the light source 2' of the backup lamp 52 is 75 mm or less so that the emitted lights L and L' are visually recognized integrally.

[0023] Fig. 5 shows the image projection device 1 of the above configuration when it is lit. The images Gc, Gb, and Ga are drawn on a straight line A obtained by projecting the optical axis of the light L emitted from the light source 2 onto the road surface. For the image G, the image Ga projected at a position farther from the vehicle body 51 than the image Gc projected at a position closer to the vehicle body 51 is longer (Dc < Db < Da) in the vehicle length direction. Also, for the image G, the image Ga projected at a position farther from the vehicle body 51 than the image Gc projected at a position closer to the vehicle body 51 is wider (Wc < Wb < Wa) in the vehicle width direction.

[0024] Here, the suitable projection distance D of the image G in the vehicle length direction varies depending on the mounting position of the image projection device 1. For example, in the case of a headlamp or the backup lamp 52, it is preferably within 3 m, and in the case of a side turn signal lamp, it is preferably within 5 m. In particular, in the case of the backup lamp 52, it is most preferable that the projection distance D is 2.5 m. Also, it is preferable to adjust the light source 2 so that the brightness of the image G is about 7000 cd at the brightest position P. Also, in this example, for Gc, Gb, and Ga, the length D of the image G in the vehicle length direction increases (Dc < Db < Da), and the length W in the vehicle width direction also increases (Wc < Wb < Wa).

[0025] Next, based on Figs. 6 to 8, a modified example of the image projection device 1 is shown. The image projection device 1 can also be arranged in parallel with vehicle lamps other than the backup lamp 52, such as a headlamp 54 or a side turn signal lamp, or provided inside the lamp chamber of the vehicle lamp. In this modified example, an example of the case where it is provided inside the lamp chamber of the headlamp 54 is shown. Also in this case, it is desirable that the distance d between the light source 2'' of the headlamp 54 and the light source 2 is 75 mm or less.

[0026] As shown in Figures 6 and 7, in the modified image projection device 1, the lenses 4 are arranged horizontally. Lenses 4c, 4b, and 4a each have different diameters r (diameter rc < diameter rb < diameter ra), and are arranged so that the diameter r increases as you move inward (towards the axle). In addition, the lenses 4 are mounted in a position where the entire lens 4 is tilted toward the side of the vehicle body. By appropriately adjusting the tilt angle θ1 of the entire lens 4, the tilt angle θ2 toward the side of the vehicle body of the image G can be changed.

[0027] As shown in Figure 7(a), the lenses 4 are positioned so that the optical axes of the light rays Lc, Lb, and Lc that have passed through lenses 4c, 4b, and 4a intersect in a plan view. Furthermore, as shown in Figure 7(b), the vertical tilt of the lenses 4 is adjusted so that the smaller the diameter of lens 4c, the closer the image Gc is projected to the vehicle body 51, and the larger the diameter of lens 4a, the further away the image Ga is projected to the vehicle body 51.

[0028] Figure 8 shows the modified image projection device 1 when illuminated. Images Gc, Gb, and Ga are drawn on a straight line A projected onto the road surface by the optical axis of light L emitted from the light source 2. Image G is longer in the vehicle length direction when projected at a position further from the vehicle body 51 than image Gc is projected at a position closer to the vehicle body 51. Also, image G is wider in the vehicle width direction when projected at a position further from the vehicle body 51 than image Gc is projected at a position closer to the vehicle body 51.

[0029] As described above, the image projection device 1 is configured such that multiple lenses 4c, 4b, and 4a are provided with different diameters rc, rb, and ra, respectively. For example, the lens 4b with a larger diameter r projects the image Gb at a position further away from the image projection device 1 than the lens 4c with a smaller diameter r. Therefore, even when using light sources 2c, 2b, and 2c with the same luminous flux, images Gc, Gb, and Gc can be projected with similar illumination regardless of the distance from the vehicle 51, and variations in the brightness of the image G can be suppressed. In addition, the focus of each projected image G can be adjusted using the lenses 4c, 4b, and 4a, allowing for the projection of clear images Gc, Gb, and Ga. Furthermore, since the lenses 4c, 4b, and 4a are integrated, the image projection device 1 can be manufactured with fewer parts, reducing labor and costs. [Examples]

[0030] Hereinafter, an embodiment 2 of the present invention, which is implemented in an image projection device, will be described with reference to the drawings. The image projection device 1 shown in Figures 9 to 11 comprises a plurality of light sources 2 (2a to 2c) that emit light L to project an image G, and a control system 11 that controls the light sources 2.

[0031] The control system 11 includes an on / off control circuit 13 that turns the light source 2 on, off, and sequentially on, and an ECU 12 that controls the on / off control circuit 13. The ECU 12 receives a control signal from the control system 21 of the backup lamp 52 and controls the on / off control circuit 13 in conjunction with the on / off of the backup lamp 52.

[0032] Here, sequential lighting refers to a control method in which the light source 2 is lit in the order of light source 2c, light source 2b, and light source 2a with predetermined time intervals in between, then turned off, and then the light source 2 is lit again in the order of light source 2c, light source 2b, and light source 2a with predetermined time intervals in between. In sequential lighting, when the light source 2 is lit in the order of light source 2c, light source 2b, and light source 2a, the images are projected onto the road surface R in the order of image Gc, image Gb, and image Ga, starting from the image G closest to the vehicle body 51.

[0033] As shown in Figure 10, the image projection device 1 consists of a substrate 7 on which a light source 2 is mounted, an attachment 5 for attaching a shade 3 to the substrate 7, a shade 3 that cuts the light L from the light source 2 into a shape corresponding to the image G, a lens 4 that transmits the light L from the light source 2, and an extension 6 that shields the internal structure of the image projection device 1 from the outside of the vehicle.

[0034] Light sources 2a to 2c are LEDs with the same current value and brightness, and are arranged vertically. Arranging the light sources vertically has the advantage of simplifying the optical design of the lens compared to arranging them horizontally.

[0035] Light source 2 is positioned so that the light La to Lc emitted from light sources 2a to 2c is inclined diagonally upwards toward the road surface R. This arrangement projects an image Ga to Gc extending in the direction of the vehicle length onto the road surface.

[0036] Light sources 2a to 2c are arranged in a straight line with the image drawn by the light from light source 2 in a plan view. By arranging light source 2 and images Ga to Gc in a straight line, it becomes easier to understand that the images belong to the same function compared to when light source 2 and image G are projected scattered to the left and right. In this case, vehicle lighting fixtures (e.g., backup lamps 52) installed alongside light source 2 may also be configured to be arranged in a straight line with light source 2 and image G.

[0037] The shade 3 is provided with a trapezoidal opening 31 having an upper base 32 that is longer than the lower base 33. By appropriately adjusting the ratio of the upper base 32 to the lower base 33, the shape of the projected image G can be adjusted. For example, it is also possible to provide a rectangular opening 31 and project a trapezoidal image G that widens as it moves further away from the vehicle.

[0038] The shape and area of ​​all the openings 31 are identical. By making the area and shape of the openings 31 identical, the structure of the shade 3 can be simplified and manufacturing costs can be reduced.

[0039] Multiple lenses 4 (4a-4c) are integrally formed and configured to transmit multiple light rays L1-L3 from multiple light sources 2a-2c, respectively. Lenses 4a-4c each have different diameters, with the diameter decreasing towards the bottom. To prevent overlapping, the distance between lenses 4 increases as their diameters increase. Furthermore, the position of each lens 4 relative to the light source 2 is determined according to its own focal length.

[0040] In this configuration, the tilt of lens 4 is adjusted so that the light L passing through the larger diameter lens 2 projects the image G further away than the light L passing through the smaller diameter lens 2. The tilt of lens 4 is set to be greater for lenses 4 that project closer to the vehicle projection device 1 or the vehicle body 51. With this adjustment, the light beam passing through the larger diameter lens 2 is greater than the light beam passing through the smaller diameter lens 2, so the image G can be projected with the same illuminance regardless of the distance from the vehicle body 51. It is also possible to arrange the lenses 4 so that their diameters increase towards the bottom. In this case as well, it is preferable to adjust the tilt of lens 4 so that the image G is projected further away from the vehicle body 51 for larger diameter lenses 4.

[0041] As shown in Figure 12, the image projection device 1 is positioned on the underside of the bumper 53. The light L from the image projection device 1 is brighter than other vehicle lights, making it prone to glare. By positioning it on the underside of the bumper, it is expected that glare will be suppressed. The image projection device 1 is also positioned alongside the backup lamp 52, so that the light L emitted from the light source 2 is visible as a single unit with the light L' from the backup lamp 52. In particular, to ensure that the emitted lights L and L' are visible as a single unit, it is desirable that the distance d between the light source 2 and the light source 2' of the backup lamp 52 be 75 mm or less.

[0042] Figure 13 shows the image projection device 1 with the above configuration illuminated. Images Ga to Gc are drawn on a straight line A projected onto the road surface R by the optical axes of light sources 2a to 2c. Image G is longer in the vehicle length direction (Da>Db>Dc) when projected at a position further from the vehicle body 51 than when projected at a position closer to the vehicle body 51. Also, image G is wider in the vehicle width direction (Wa>Wb>Wc) when projected at a position further from the vehicle body 51 than when projected at a position closer to the vehicle body 51.

[0043] The image projection device 1 can also be installed alongside other vehicle lighting fixtures besides the backup lamp 52, such as headlights and side turn signal lamps. Figure 14(a) schematically shows the projected image G when installed alongside a side turn signal lamp, and Figure 14(b) shows the projected image G when installed alongside a headlight. When installed alongside the backup lamp 52 or headlight, the image G is projected inward beyond the vehicle width. On the other hand, when installed alongside a side turn signal lamp, the image G is projected to unfold to the left and right as it moves away from the vehicle body 51.

[0044] Here, the preferred projection distance D of image G in the vehicle length direction varies depending on the mounting position of the image projection device 1. For example, it is preferable to have a projection distance of 3m or less for headlights and backup lamps 52, and within 5m for side turn signal lamps. In particular, for backup lamps 52, it is most preferable to have a projection distance D of 2.5m. Furthermore, it is preferable to adjust the light source 2 so that the brightness of image G is approximately 7000 cd at the brightest position P. It is also preferable to adjust the optical performance so that the brightness of image G has a Michelson contrast of 0.2 or more at the brightest position P.

[0045] Next, the on / off control by the control system 11 in the image projection device 1 configured as described above will be explained. When the vehicle starts to reverse, the control system 21 of the backup lamp 52 controls the backup lamp 52 to light up. At this time, the ECU 22 of the backup lamp 52 transmits a control signal to the control system 11 of the image projection device 1. Upon receiving the control signal, the ECU 12 of the control system 11 lights up all of the light sources 2a to 2c of the image projection device 1. When sequential lighting is performed, the ECU 12 lights up light source 2c, light source 2b, and light source 2a in that order. At this time, from outside the vehicle, it appears as if the backup lamp 52 and light source 2 (light source 2c in the case of sequential lighting) are lit simultaneously.

[0046] With the image projection device 1 described above, since the image G is projected in conjunction with other vehicle lighting fixtures such as the backup lamp 52, the message that the vehicle is reversing can be more clearly conveyed to the outside of the vehicle. In addition, since the area and shape of the opening 31 of the shade 3 that forms the image G are made the same, the structure of the shade 3 can be simplified and manufacturing costs can be reduced. Furthermore, since multiple images Ga~Gc can be projected simultaneously or sequentially using one shade 3 and one lens 4, the number of parts can be reduced and costs can be lowered. [Examples]

[0047] Hereinafter, Embodiment 3, which embodies the present invention in an image projection device, will be described with reference to the drawings. The image projection device 1 shown in Figures 15 and 16 comprises a plurality of light sources 2 (2a to 2c) mounted near a backup lamp 52 and emitting light L (La to Lc) that projects an image G (Ga to Gc), a plurality of lenses 4 (4a to 4c) each facing the plurality of light sources 2, and a shade 3 interposed between the light sources 2 and the lenses 4.

[0048] As shown in Figure 16, the image projection device 1 consists of a substrate 7 on which a light source 2 is mounted, an attachment 5 for attaching a shade 3 to the substrate 7, a flat shade 3 that cuts the light L from the light source 2 into a predetermined shape, a lens 4 that transmits the light L from the light source 2, and an extension 6 that shields the internal structure of the image projection device 1 from the outside of the vehicle.

[0049] Light sources 2a to 2c are LEDs with the same luminous flux, that is, LEDs with the same current value and the same brightness, and are arranged vertically. Arranging the light sources vertically has the advantage of simplifying the optical design of the lens compared to arranging them horizontally.

[0050] Multiple lenses 4 (4a-4c) are integrally formed and configured to transmit multiple light rays La-Lc from multiple light sources 2a-2c, respectively. Lenses 4a-4c each have different diameters, with the diameter decreasing towards the bottom. To prevent overlapping, the distance between lenses 4 increases as their diameters increase. Furthermore, the position of each lens 4 relative to the light source 2 is determined according to its own focal length.

[0051] In this configuration, the tilt of lens 4 is adjusted so that the light L passing through the larger diameter lens 2 projects the image G further away than the light L passing through the smaller diameter lens 2. The tilt of lens 4 is set to be greater for lenses 4 that project closer to the vehicle projection device 1 or the vehicle body 51. With this adjustment, the light beam passing through the larger diameter lens 2 is greater than the light beam passing through the smaller diameter lens 2, so the image G can be projected with the same illuminance regardless of the distance from the vehicle body 51. It is also possible to arrange the lenses 4 so that their diameters increase towards the bottom. In this case as well, it is preferable to adjust the tilt of lens 4 so that the image G is projected further away from the vehicle body 51 for larger diameter lenses 4.

[0052] As shown in Figure 17(a), the vehicle projection device 1 is configured such that light L emitted from light sources 2a to 2c descends towards the road surface R at an inclined angle. At this time, as shown in Figure 17(b), images Ga to Gc extending in the vehicle length direction are projected onto the road surface R. Furthermore, the light source 2 is positioned on the same straight line A as the image G drawn by the light L from the light source 2. By arranging the light source 2 and the image G in a line on the same straight line A, it becomes easier to understand that the images belong to the same function compared to when the light source 2 and the image G are projected scattered to the left and right. In this case, the vehicle lighting equipment (e.g., backup lamp 52) installed alongside the light source 2 may also be configured to be positioned on a straight line with the light source 2 and the image G.

[0053] As shown in Figure 18, when the focal point F is within the lens, the light passing through the aperture 31 of the shade 3 is inverted and projected at the focal point F of the lens 4. Therefore, the light L that passes near the upper bottom 32 of the aperture 31 is projected near the side G1 that is closer to the vehicle body 51, and the light L that passes near the lower bottom 33 is projected near the side G2 that is further away from the vehicle body 51 (see Figure 19).

[0054] Furthermore, as shown in Figure 18(b), the openings 31 are arranged in series along the longitudinal direction of the shade 3. The size of the openings 31 is set to match the size of the LED chip, which is the light source 2. The height h of the openings 31 is preferably about 0.9 mm. The distances k1 and k2 between the openings 31 are set to be different from each other according to the size and inclination of the lens 4.

[0055] Figure 19(a) shows the image G' projected when a rectangular aperture 31' is provided while the focal point F is within the lens, and Figure 19(b) shows the image G projected when a trapezoidal aperture 31 is provided while the focal point F is within the lens, with the lower base 33 being shorter than the upper base 32. In Figure 19(b), compared to Figure 19(a), the elongation of the side G2 farther from the vehicle body 51 is suppressed (G2'>G2), and a band-shaped image G extending in the direction of the vehicle length is projected.

[0056] As shown in Fig. 20, the image projection device 1 may be configured such that the light passing through the opening 31 of the shade 3 travels straight through the inside of the lens 4. At this time, no focal point F is arranged inside the lens. In this case, the light L passing near the upper base 32 of the opening 31 is projected near the side G2 far from the vehicle body 51, and the light L passing near the lower base 33 is projected near the side G1 close to the vehicle body 51 (see Fig. 21).

[0057] Fig. 21(a) shows an image G' projected when a rectangular opening 31' is provided when there is no focal point F inside the lens, and Fig. 21(b) shows an image G projected when a trapezoidal opening 31 with a lower base 33 longer than the upper base 32 is provided when there is no focal point F inside the lens. In Fig. 21(b), compared with Fig. 21(a), the elongation of the side G2 far from the vehicle body 51 is suppressed (G2'>G2), and a strip-shaped image G extending in the vehicle length direction is projected.

[0058] Fig. 22 shows the state of the image projection device 1 of the above configuration being lit. The images Ga to Gc are drawn on a straight line A obtained by projecting the optical axis of the light L emitted from the light source 2 onto the road surface R. The image G is longer in the vehicle length direction and extends further than the image Gc projected at a position closer to the vehicle body 51 and farther from the vehicle body 51. Also, the image G is wider in the vehicle width direction than the image Gc projected at a position closer to the vehicle body 51 and farther from the vehicle body 51.

[0059] Here, the suitable projection distance D of the image G in the vehicle length direction varies depending on the mounting position of the image projection device 1. For example, in the case of a headlight or a backup lamp 52, it is preferably within 3 m, and in the case of a side turn signal lamp, it is preferably within 5 m. In particular, in the case of the backup lamp 52, it is most preferable to set the projection distance D to 2.5 m. Also, the brightness of the image G is preferably adjusted so that the Michelson contrast is 0.2 or more at the brightest position P. Further, in this example, from Gc, Gb, to Ga, the length D of the image G in the vehicle length direction increases (Dc<Db<Da), and the length W in the vehicle width direction also increases (Wc<Wb<Wa).

[0060] Next, a modified version of the image projection device 1 is shown based on Figures 23-26. The image projection device 1 can also be installed alongside other vehicle lighting fixtures besides the backup lamp 52, such as the headlight 54 or side turn signal lamps, or installed inside the lamp chamber of the vehicle lighting fixture. This modified version shows an example where it is installed inside the lamp chamber of the headlight 54.

[0061] As shown in Figures 23 and 24, in the modified image projection device 1, the lenses 4 are arranged horizontally. Lenses 4a to 4c each have different diameters, and are arranged so that the diameter increases towards the inside (axle side). In addition, the lenses 4 are mounted in a position where the entire lens 4 is tilted toward the side of the vehicle body. By appropriately adjusting the tilt angle θ1 of the entire lens 4, the tilt angle θ2 toward the side of the vehicle body of the image G (see Figure 12(a)) can be changed.

[0062] As shown in Figure 24(a), the lenses 4 are positioned so that the optical axes of light La to Lc, which have passed through lenses 4a to 4c, intersect in a plan view. Furthermore, as shown in Figure 24(b), the vertical tilt of the lenses 4 is adjusted so that smaller diameter lenses 4 project the image G closer to the vehicle body 51, and larger diameter lenses 4 project the image G further away from the vehicle body 51.

[0063] As shown in Figure 25, the opening 31 of the modified shade 3 is provided in a trapezoidal shape, with the upper base 32 being longer than the lower base 33. Here, the openings opposite the lenses 4a, 4b, and 4c are denoted as 31a, 31b, and 31c, respectively. Each opening 31 is inclined downward toward the axle, and the bottom angle of the upper base 32 facing the side of the vehicle body is set such that θa > θb > θc, where θa, θb, and θc are the angles of the bottom angles of the openings 31a, 31b, and 31c, respectively. Furthermore, the openings 31 are provided with different sizes (areas). With this configuration, the elongation of the width W of multiple images G projected by light L that intersect each other in a plan view and have different vertical inclinations can be suppressed.

[0064] Figure 26 shows the modified image projection device 1 when illuminated. Images Ga to Gc are drawn on a straight line A, which is formed by projecting the optical axis of the light L emitted from the light source 2 onto the road surface R. Image G is longer in the vehicle length direction when projected at a position further from the vehicle body 51 than image Gc, which is projected at a position closer to the vehicle body 51. Also, image G is wider in the vehicle width direction when projected at a position further from the vehicle body 51 than image Gc, which is projected at a position closer to the vehicle body 51.

[0065] As described above, the image projection device 1 has a trapezoidal shape for the opening 31, and the longer of the upper base 32 or lower base 33 is configured to correspond to the side G2 that is drawn further away from the image projection device 1 and the vehicle body 51. This has the effect of suppressing the stretching of the image in the width direction and projecting a band-shaped image that extends in the length direction of the vehicle. Furthermore, since multiple openings 31 are formed together in the shade 3, the image projection device 1 can be manufactured with a small number of parts, which reduces labor and costs.

[0066] It should be noted that the present invention is not limited to the embodiments described above, and it is possible to implement the invention by appropriately changing the shape and configuration of each part without departing from the spirit of the invention. For example, although an example of operation in conjunction with the backup lamp 52 has been described, the projection onto the road surface may be started in conjunction with the illumination of the head lamps, for example. Alternatively, the projection onto the road surface as a starting light may be started simultaneously with the illumination of the low beams, for example. [Explanation of symbols]

[0067] 1. Image projection device 2 light source 3 Shades 4 lenses 5 Attachments 6 Extensions 7 circuit boards 11. Control System (Image Projection Device) 12 ECU (Image Projection Unit) 13. Lighting control circuit (image projection device) 21. Control System (Backup Lamp) 22 ECU (Backup Lamp) 23. Lighting control circuit (backup lamp) 31 Opening 32 Upper base (opening) 33 Bottom bottom (opening) 51 Car body 52 Backup lamp 53 Bumper 54 Headlights G Image P: Brightest position in the image D Projection distance W: Width of the image d Distance between light sources L light A straight line R road surface

Claims

1. An image projection device for vehicles, The system comprises multiple light sources, multiple lenses facing each of the multiple light sources, and a plate-shaped shade interposed between the light sources and the lenses. The shade comprises a plurality of openings that allow light from a plurality of light sources to pass towards a plurality of lenses, An image projection device characterized by having the aforementioned opening in a trapezoidal shape.

2. The image projection device according to claim 1, wherein the shape of the opening is a trapezoidal shape in which the lower base is shorter than the upper base.

3. The image projection apparatus according to claim 1 or 2, wherein the openings are arranged in series.

4. The shade has three or more of the openings, The image projection apparatus according to any one of claims 1 to 3, wherein the distances between the openings are arranged to be different from each other.

5. The image projection apparatus according to any one of claims 1 to 4, wherein the plurality of openings are provided, each of a different size.

Images