JP7852028B2 - Image projection device - Google Patents

Description

This invention relates to an image projection device for vehicles that projects a predetermined image onto a road surface.

Conventionally, technologies have been known for vehicle lighting that project images onto the road surface to attract the attention of surrounding vehicles and pedestrians, or to assist the driver. For example, Patent Document 1 proposes an invention for a departure notification display device that uses light to draw a predetermined shape of departure notification on the road surface in the direction of vehicle travel, allowing pedestrians and others to accurately understand the timing of the vehicle's departure.

Japanese Patent Publication No. 2020-55519

Vehicles are equipped with various vehicle lighting devices, including headlights, backup lights, and turn signals. These vehicle lighting devices also have functions to display the vehicle's driving status to surrounding vehicles and pedestrians, thereby alerting them to potential hazards. Therefore, there was a request to coordinate vehicle lighting devices with image projection devices to provide more appropriate displays to those outside the vehicle.

Therefore, the first object of the present invention is to provide an image projection device that can coordinate with other vehicle lighting devices to provide a more appropriate display to the outside of the vehicle.

Furthermore, when projecting an image onto the road surface using an image projection device, the light is projected from an oblique upward direction towards the road surface. This results in the image width being stretched as the distance from the vehicle increases, leading to the problem of the desired image not being displayed.

Therefore, the second objective of the present invention is to provide an image projection device that can project an image with a well-balanced shape, both in the parts close to the vehicle body and the parts far from the vehicle body.

To solve the first problem described above, the present invention provides a vehicle image projection device capable of projecting multiple images onto a road surface simultaneously, comprising: multiple light sources that emit light for projecting multiple images; and control means for controlling the light sources. The control means is characterized by controlling the light sources to turn on and off in conjunction with the on/off of other vehicle lights.

The control system can also sequentially illuminate multiple light sources.

Other vehicle lighting fixtures can include backup lamps and turn signal lamps.

The image projection device of the present invention is installed alongside other vehicle lighting fixtures, and the light emitted from the light source is viewed as an integrated whole with the light emitted from the other vehicle lighting fixtures.

It is also possible to configure the system by arranging multiple light sources vertically and projecting an image that extends in the vehicle's length direction using the light emitted from these multiple light sources.

The light source and the image drawn by the light from the light source may be configured to be aligned in a straight line when viewed from a planar perspective.

It is also preferable to position the light source on the underside of the bumper.

To solve the second problem described above, the present invention provides an image projection device for a vehicle, comprising: a plurality of light sources; a plurality of lenses each facing the plurality of light sources; and a plate-shaped shade interposed between the light sources and the lenses. The shade is characterized by having a plurality of openings that allow light from the plurality of light sources to pass towards the plurality of lenses, and the openings are arranged in a trapezoidal shape.

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

It is also possible to provide three or more openings in the shade, arranging them so that the distances between them differ.

Multiple openings can be provided, each of different sizes.

According to the image projection apparatus of the present invention, the larger diameter lens is configured to project the image at a position further away from the projection apparatus than the smaller diameter lens, and the illumination of the image increases as it moves away from the projection apparatus. This configuration effectively suppresses variations in the brightness and darkness of the projected image.

Furthermore, because the image projection device of the present invention is controlled to illuminate in conjunction with other vehicle lights, it has the effect of more clearly conveying the message displayed by the vehicle lights to the outside of the vehicle.

Furthermore, 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. Because the opening is trapezoidal in shape, by adjusting the lengths of the upper and lower bases of the trapezoid, a well-balanced projection can be achieved for both parts of the vehicle body close to and far from the vehicle body, with a simple configuration.

This is a schematic diagram of the image projection device of Embodiment 1 of the present invention. Figure 1 is a schematic exploded perspective view of the image projection device. Figure 1 is a schematic diagram showing the positional relationship between the image projection device and the obstacle, as well as the light distribution state. Figure 1 is a schematic diagram showing the image projection device installed alongside the backup lamp. Figure 1 is a schematic diagram showing the image projected by the image projection device. This is a schematic diagram showing how a modified image projection device is installed inside the headlight housing. Figure 6 shows the arrangement and orientation of the lenses of the image projection device, (a) a schematic cross-sectional view of the lens portion AA, and (b) a schematic diagram showing the tilt state of the lenses. Figure 6 is a schematic diagram showing the image projected by the image projection device. This is a schematic diagram of the image projection device of Embodiment 2 of the present invention. This is a schematic exploded perspective view of an image projection device. This is a schematic diagram showing the projection state of the image projection device onto the road surface. This is a schematic diagram showing the arrangement of the image projection device. This is a schematic diagram showing an image projected by an image projection device installed alongside a backup lamp. This is a schematic diagram showing the projected image from an image projection device. (a) shows the case of a side turn signal lamp, and (b) shows the case of a headlight. This is a schematic diagram of the image projection device of Embodiment 3 of the present invention. Figure 15 is a schematic exploded perspective view of the image projection device. Figure 15 shows the optical axis, light beam, and projected image of the image projection device, with (a) a schematic diagram viewed from above and (b) a schematic diagram viewed from the side. (a) A schematic cross-sectional view of the AA when the focal point is located within the lens, and (b) A schematic view of the shade as seen from the front of the device. Figure 18 is a schematic diagram showing (a) the projected image through a rectangular opening and (b) the projected image through a trapezoidal opening. (a) A schematic cross-sectional view of the AA lens when the focal point is not located within the lens, and (b) A schematic view of the shade as seen from the front of the device. Figure 20 is a schematic diagram showing (a) the projected image through a rectangular opening and (b) the projected image through a trapezoidal opening. Figure 15 is a schematic plan view showing the image projection device and the projected image. This is a schematic diagram showing how a modified image projection device is installed inside the headlight housing. Figure 23 shows the arrangement and orientation of the lenses of the image projection device, (a) a schematic cross-sectional view of the lens section, and (b) a schematic view of the tilt state of each lens as seen from the side. Figure 23 shows the shade of the image projection device as viewed from the front of the device (a) and (b) an enlarged view of the opening. Figure 23 is a schematic plan view showing the image projection device and the projected image.

The following describes Embodiment 1, an image projection device embodying the present invention, based on the drawings. The image projection device 1 shown in Figures 1 and 2 comprises a plurality of light sources 2 (2c, 2b, 2a) that emit light L (Lc, Lb, Lc()) for projecting an image G (Gc, Gb, Ga), and a plurality of lenses 4 (4c, 4b, 4a) facing each of the plurality of light sources 2.

As shown in Figure 2, 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.

Light sources 2c, 2b, and 2c are LEDs with the same luminous flux, that is, 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.

Light source 2 is configured such that the light Lc, Lb, Lc emitted from light sources 2c, 2b, and 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.

Furthermore, the light source 2 is positioned on the same line as the image G projected by the light L from the light source 2 (see Figures 5 and 8). By aligning 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 separately to the left and right. In this case, the vehicle lighting fixtures (e.g., backup lamps 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.

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 possible to project a trapezoidal image G that widens as it moves away from the vehicle body 51 by providing a rectangular opening 31.

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 identical, the structure of the shade 3 can be simplified, and manufacturing costs can be reduced.

Multiple lenses 4 (4c, 4b, 4a) are integrally formed and configured to pass multiple light rays Lc, Lb, Lc( from multiple light sources 2c, 2b, 2c) through each lens. 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.

The lens 2 with a larger diameter r is positioned to project the image G at a greater distance from the vehicle body 51 than the 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 greater distance 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, the image Gb, which is further away from the vehicle body 51, can be projected with the same illuminance as the image Gc, which is closer to the vehicle body 51.

Lens 4 is positioned such that the optical axes of light Lc, Lb, and Lc, which pass through lenses 4c, 4b, and 4a, are non-parallel to each other. The optical axes of Lc, Lb, and Lc intersect in a side view, and images Gc, Gb, and Ga are projected in the order of light source 2c (located above), light source 2b (located in the middle), and light source 2a (located 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 becomes possible to project 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 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).

As shown in Figure 4, the image projection device 1 is positioned alongside the backup lamp 52, and is configured so that the light L emitted from the light source 2 and the light L' from the backup lamp 52 are visible as a single unit. In particular, to ensure that the emitted light L and L' are visible as a single unit, the distance d between the light source 2 and the light source 2' of the backup lamp 52 is preferably 75 mm or less.

Figure 5 shows the image projection device 1 with the above configuration illuminated. Images Gc, Gb, and Ga are drawn on a straight line A projected onto the road surface by the optical axis of the light L emitted from the light source 2. Image G is longer in the vehicle length direction (Dc < Db < Da) 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 (Wc < Wb < Wa) 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.

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, a projection distance D of 2.5m is most preferable. 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. In this example, the length D of image G in the vehicle length direction increases from Gc to Gb to Ga (Dc < Db < Da), and the length W in the vehicle width direction also increases (Wc < Wb < Wa).

Next, a modified example of the image projection device 1 is shown based on Figures 6-8. 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 example shows a case where the device is installed inside the lamp chamber of the headlight 54. Even in this case, it is desirable that the distance d between the light source 2'' of the headlight 54 and the light source 2 be 75 mm or less.

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 towards the inside (axle side). Furthermore, 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.

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 pass 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 diameter lens 4c projects the image Gc closer to the vehicle body 51, while the larger diameter lens 4a projects the image Ga further away from the vehicle body 51.

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 the 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.

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. 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, suppressing variations in the brightness of the image G. Furthermore, the lenses 4c, 4b, and 4a allow for adjustment of the focus of each projected image G, enabling the projection of clear images Gc, Gb, and Ga. Additionally, because the lenses 4c, 4b, and 4a are integrated, the image projection device 1 can be manufactured with fewer parts, reducing labor and costs.

The following describes Embodiment 2, which embodies the present invention in an image projection device, based on the drawings. The image projection device 1 shown in Figures 9-11 comprises a plurality of light sources 2 (2a-2c) that emit light L to project an image G, and a control system 11 that controls the light sources 2.

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.

Here, sequential lighting refers to a control method in which light source 2 is illuminated in the order of light source 2c, light source 2b, and light source 2a at predetermined time intervals, then turned off, and then the light source 2 is illuminated again in the order of light source 2c, light source 2b, and light source 2a at predetermined time intervals, and this process is repeated. In sequential lighting, when light source 2 is illuminated in the order of light source 2c, light source 2b, and light source 2a, the images G closest to the vehicle body 51 are projected onto the road surface R in the order of image Gc, image Gb, and image Ga.

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.

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.

Light source 2 is positioned so that the light rays La to Lc emitted from light sources 2a to 2c are inclined diagonally upwards toward the road surface R. This arrangement projects images Ga to Gc onto the road surface, extending in the direction of the vehicle's length.

Light sources 2a to 2c are arranged in a straight line with the image projected 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 clearer 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. Furthermore, 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.

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 possible to project a trapezoidal image G that widens as it moves further away from the vehicle by providing a rectangular opening 31.

The shape and area of all 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.

Multiple lenses 4 (4a-4c) are integrally formed and configured to transmit multiple light beams 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.

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 projecting 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, allowing the image G to be projected with equivalent 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.

As shown in Figure 12, the image projection device 1 is positioned on the underside of the bumper 53. Because the light L from the image projection device 1 is brighter than other vehicle lights, it is prone to causing glare. Positioning it on the underside of the bumper is expected to suppress glare. Furthermore, the image projection device 1 is 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, the distance d between the light source 2 and the light source 2' of the backup lamp 52 is preferably 75 mm or less.

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. Furthermore, 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.

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.

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 5m or less for side turn signal lamps. In particular, for backup lamps 52, a projection distance D of 2.5m is most preferable. 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 higher at the brightest position P.

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 begins to reverse, the control system 21 of the backup lamp 52 performs control to illuminate the backup lamp 52. 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 illuminates all of the light sources 2a to 2c of the image projection device 1. In the case of sequential illumination, the ECU 12 illuminates 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 illumination) are illuminated simultaneously.

The image projection device 1 described above projects image G in conjunction with other vehicle lighting fixtures such as backup lamps 52, thereby more clearly communicating the message that the vehicle is reversing to the outside of the vehicle. Furthermore, by making the area and shape of the opening 31 of the shade 3 that forms image G the same, the structure of the shade 3 can be simplified, reducing manufacturing costs. Moreover, since multiple images Ga to Gc can be projected simultaneously or sequentially using a single shade 3 and a single lens 4, the number of parts can be reduced, lowering costs.

The following describes Embodiment 3, which embodies the present invention in an image projection device, based on 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) to project 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.

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.

Light sources 2a to 2c are LEDs with the same luminous flux, that is, 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.

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.

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 projecting 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, allowing the image G to be projected with equivalent 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.

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.

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 passing near the upper base 32 of the aperture 31 is projected near the side G1 closest to the vehicle body 51, and the light L passing near the lower base 33 is projected near the side G2 furthest from the vehicle body 51 (see Figure 19).

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.

Figure 19(a) shows the image G' projected when a rectangular aperture 31' is provided with a focal point F within the lens, and Figure 19(b) shows the image G projected when a trapezoidal aperture 31 is provided with a lower base 33 shorter than the upper base 32, with a focal point F within the lens. 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.

As shown in Figure 20, the image projection device 1 may be configured such that light passing through the opening 31 of the shade 3 travels straight through the inside of the lens 4. In this case, the focal point F is not located inside the lens. In this case, light L passing near the upper bottom 32 of the opening 31 is projected near the side G2 far from the vehicle body 51, and light L passing near the lower bottom 33 is projected near the side G1 close to the vehicle body 51 (see Figure 21).

Figure 21(a) shows the image G' projected when a rectangular aperture 31' is provided, and there is no focal point F within the lens. Figure 21(b) shows the image G projected when a trapezoidal aperture 31 is provided, where the lower base 33 is longer than the upper base 32, and there is no focal point F within the lens. In Figure 21(b), compared to Figure 21(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.

Figure 22 shows the image projection device 1 with the above configuration 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.

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, a projection distance D of 2.5m is most preferable. Furthermore, it is 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. In addition, in this example, the length D of image G in the vehicle length direction increases from Gc to Gb to Ga (Dc < Db < Da), and the length W in the vehicle width direction also increases (Wc < Wb < Wa).

Next, a modified version of the image projection device 1 is shown based on Figures 23 to 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.

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, with the diameter increasing towards the inside (axle side). Furthermore, 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.

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 such that smaller diameter lenses 4 project the image G closer to the vehicle body 51, while larger diameter lenses 4 project the image G further away from the vehicle body 51.

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 designated as 31a, 31b, and 31c, respectively. Each opening 31 is inclined downwards 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). This configuration suppresses 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.

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 when projected at a position closer to the vehicle body 51 than image Gc, which is projected at a position closer to the vehicle body 51.

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 projected further away from the image projection device 1 and the vehicle body 51. This configuration suppresses the stretching of the image in the width direction, allowing for the projection of a strip-shaped image that extends in the vehicle length direction. Furthermore, because multiple openings 31 are formed together in the shade 3, the image projection device 1 can be manufactured with fewer parts, reducing labor and costs.

Furthermore, the present invention is not limited to the embodiments described above, and it is possible to implement the invention by appropriately modifying 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 headlights. Alternatively, the projection onto the road surface as a starting light may be started simultaneously with the illumination of the low beams.

1. Image projection device 2. Light source 3. Shade 4. Lens 5. Attachment 6. Extension 7. Circuit board 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 Body 52 Backup lamp 53 Bumper 54 Headlight G Image P Brightest point 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 (7)

A vehicle image projection device capable of projecting multiple images onto the road surface at once,
The system comprises a plurality of light sources that each emit light to project the plurality of images, and control means for controlling the light sources,
The aforementioned multiple images are projected in multiple rows, parallel to each other, and are narrower than the width of the vehicle.
The image that is farther from the vehicle body is projected to be longer in the vehicle length direction and wider in the vehicle width direction than the image that is closer to the vehicle body.
The control means is characterized by turning the light source on and off in conjunction with the on and off of other vehicle lights. The control means is an image projection apparatus according to claim 1, which sequentially illuminates the plurality of light sources. The image projection device according to claim 1 or 2, wherein the other vehicle lighting fixture is a backup lamp. The image projection device is installed alongside the other vehicle lighting fixtures.
The image projection device according to any one of claims 1 to 3, wherein the light emitted from the light source is visible together with the light emitted from the other vehicle lighting device. An image projection device according to any one of claims 1 to 4, wherein the plurality of light sources are arranged vertically in parallel, and an image extending in the vehicle length direction is projected using the light emitted by the plurality of light sources. The image projection apparatus according to any one of claims 1 to 5, wherein the light source and the image drawn by the light from the light source are arranged in a straight line in a plan view. The image projection device according to any one of claims 1 to 6, wherein the light source is positioned below the bumper.