JP2005139772A - Road face image forming system and optical substance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a road face image forming system improving the optical visibility of an arbitral shape irradiated on the road face and the optical substance. <P>SOLUTION: The road face image forming system 1 expresses the predetermined shape on a road face 3 by visible light, an optical substance reflecting the visible light LR of a specific frequency zone which is a narrow frequency zone in the vicinity of the specific frequency and absorbing visible light VR in the specific frequency zone except the specific frequency zone having a narrow frequency zone in the vicinity of the specific frequency is provided and the visible light LR of the specific frequency zone is irradiated from an advancing course estimation device 2 in the predetermined shape onto the road face 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a road surface rendering system and an optical object that display a predetermined shape on a road surface with visible light.

In recent years, in order to further improve safety in automobiles, development of a course prediction apparatus that predicts the course of the host vehicle from the running state and the driving operation state has been promoted. In the course prediction device, it is necessary to inform the driver of the predicted course. As one of methods for notifying the predicted course, a method of irradiating light having a shape indicating the predicted course on the road surface and displaying the course information using the light has been studied. When transmitting information by light irradiated on the road surface, it is important to make a driver, a pedestrian, etc. visually recognize what information (shape) is represented by the irradiated light. To improve the visibility of the information displayed on the road surface, light retroreflective beads are embedded in the painted surface of the road marking, or the paint color of the road marking under the sodium lamp in the tunnel is a specific color. And the like (see Patent Document 1).
JP-A-9-41331 Special Table 2000-504847 Japanese Patent Laid-Open No. 7-325550

  However, when information is recognized by light on the road surface, it is very difficult to recognize the light when the surroundings are bright, such as in the daytime. Furthermore, in consideration of the case where the light radiates directly on the human eye, strong light cannot be used. Moreover, in the course prediction apparatus, in order to show the course information, it is necessary to represent various shapes with light. Therefore, if the shape is limited to a specific shape such as a road sign, the beads may be arranged according to the shape. However, in the method of arranging the beads only in such a specific location, the bead is arbitrarily arranged on the road surface. In the case of irradiating the light of the shape, the visibility of the light of the arbitrary shape cannot be improved.

  Then, this invention makes it a subject to provide the road surface description system and optical object which improve the visibility of the light of the arbitrary shapes irradiated on the road surface.

  A road surface description system according to the present invention is a road surface description system that displays a predetermined shape on a road surface with visible light, and reflects visible light in a specific frequency band, which is a narrow frequency band near a specific frequency, and other than the specific frequency band. An optical object that absorbs visible light in a certain frequency band is provided on a road surface, and visible light in a specific frequency band is irradiated on the road surface in a predetermined shape.

  In this road surface drawing system, an optical object is provided on the road surface, and visible light in a specific frequency band is irradiated on the road surface in a predetermined shape. Since this optical object has a characteristic of reflecting visible light in the specific frequency band and absorbing visible light in frequency bands other than the specific frequency band, the visible light irradiated on the road surface is reflected by the optical object. At the same time, visible light in a frequency band other than the specific frequency band from another light source (sunlight or the like) is absorbed by the optical object. Therefore, the irradiated visible light becomes reflected light, and the intensity ratio of light is relatively increased as compared with other visible light. As a result, the visibility to the irradiated visible light is improved, and even if the surroundings are bright in the daytime, even when the irradiated light is directly exposed to human eyes or safe weak visible light, the predetermined shape by the irradiated visible light Can be recognized.

  In addition, since the visible light irradiated to a road surface should just have the frequency contained in a specific frequency band, the visible light which has a predetermined frequency bandwidth may be sufficient, or a single frequency like a laser beam is used. It may be visible light.

  The optical object in the road surface drawing system of the present invention and the optical object according to the present invention have a light absorbing material that absorbs visible light, and reflect only visible light in a specific frequency band on the light incident side of the light absorbing material. A reflective layer is formed.

  In this optical object, when visible light of a specific frequency band is incident, the incident visible light is reflected by the reflective layer and radiated to the outside. Further, in this optical object, when visible light in a frequency band other than the specific frequency band is incident, the incident visible light is transmitted through the reflection layer, and the transmitted visible light is absorbed by the light absorbing material.

  Note that the light incident side is a side on which visible light in a specific frequency band to be irradiated or light from another light source enters the optical object. For example, in the case of beads or fiber-like objects, the outside of the object is the light incident side, and in the case of a chip obtained by finely cutting a sheet-like object or sheet-like object, the sky side is the light incident side when provided on the road surface. It becomes.

  In the optical object of the present invention, the reflective layer is any one of a hologram coating layer, a metal thin film layer, and a resin layer.

  In the optical object of the present invention, it is preferable that a high refractive index layer is formed on the light incident side of the reflective layer.

  In this optical object, light incident on the optical object from various directions by the high refractive index layer is refracted at an angle at which the light can enter the light absorbing material (preferably an angle perpendicular to or nearly perpendicular to the light absorbing material). The light incident on the optical object is reliably incident on the light absorbing material. As a result, the probability that visible light other than the specific frequency band can be absorbed by the light absorbing material is increased.

  In the optical object of the present invention, it is preferable that a light scattering layer is formed on the light incident side of the reflective layer or the high refractive index layer.

  In this optical object, visible light of a specific frequency band reflected by the reflection layer by the light scattering layer can be scattered in various directions. Therefore, when visible light of a specific frequency band is irradiated on the road surface in a predetermined shape, not only a person in a specific direction such as a driver can visually recognize the irradiated visible light, but is also in an arbitrary place around the area. A person can also visually recognize the irradiated visible light.

  The optical object of the present invention is any one of a bead, a chip, a sheet-like object, and a fiber-like object.

  In the case of beads, a reflective layer is formed on the surface of the spherical light absorbing material, and a high refractive index layer and a light scattering layer are further formed on the surface. In the case of a sheet-like object, a reflection layer is formed on the upper side of the ultrathin plate-like light absorbing material, and a high refractive index layer and a light scattering layer are further formed on the upper side. In the case of a chip, for example, it is formed by finely cutting this sheet-like object. In the case of a fiber-like object, a reflection layer is formed on the surface of an ultrafine cylindrical light absorber, and a high refractive index layer and a light scattering layer are further formed on the surface. Of these objects, sheet-like objects and chips are easier to manufacture and practical than other objects.

  In the road surface drawing system of the present invention, the light scattering layer formed separately from the optical object may coexist with the optical object on the road surface.

  In this road surface description system, visible light of a specific frequency band reflected by an optical object can be scattered in various directions by a light scattering layer separate from the optical object provided on the road surface.

  According to the present invention, visible light in a specific frequency band can be reflected by an optical object and visible light in a frequency band other than the specific frequency band can be absorbed, so that visible light in a specific frequency band irradiated on the road surface can be visually recognized. Thus, it is possible to easily recognize an arbitrary shape displayed on the road surface by the irradiated light.

  Embodiments of a road surface drawing system and an optical object according to the present invention will be described below with reference to the drawings.

  In the present embodiment, the road surface description system according to the present invention is configured by a route prediction device mounted on an automobile and a road surface provided with special pavement. The course prediction apparatus according to the present embodiment irradiates a road surface with a laser beam having a predetermined shape that represents the predicted course of the host vehicle in order to improve driving safety by assisting the driver. Further, the special pavement surface according to the present embodiment is provided with an optical object having a characteristic of reflecting only the laser light emitted from the course prediction device.

  A road surface drawing system 1 will be described with reference to FIG. FIG. 1 is a configuration diagram of a road surface drawing system according to the present embodiment.

  The road surface depiction system 1 includes a route prediction device 2 and a road surface 3 on which special pavement is applied. In the course prediction device 2, in order to notify the driver of the predicted course when the course is changed, a steering wheel operation is performed such as when changing the course at an intersection, junction, or branching point, or when changing the lane in two or more lanes on one side. When lit, a laser beam is irradiated on the road surface. Special pavement road surface 3 is a pedestrian crossing in consideration of places where vehicles such as intersections, junctions and junctions may change courses, places with poor visibility such as blind curves, and pedestrian safety Or a place where people and pedestrians who do not have a dedicated sidewalk are mixed.

  The course prediction device 2 is mounted on the vehicle V and is a device for notifying not only the driver but also pedestrians and other drivers around the vehicle V of the predicted course of the vehicle V. The course prediction device 2 predicts the course of the host vehicle from the traveling state of the automobile V and the driving operation state of the driver. Then, the course prediction device 2 forms a shape representing the predicted course with the laser light, and irradiates the road surface with the laser light LR having the predetermined shape. The laser light LR has a single frequency (single wavelength), and a color (wavelength) laser light (for example, a green laser light) that easily recognizes irradiation light from the surroundings even on a road surface that is exposed to light such as sunlight. ) Is used. The laser light LR emitted from the course prediction device 2 is light with low intensity that is safe even when the laser light LR is directly irradiated to the human eye.

  The special pavement surface 3 is a road surface in which special pavement is applied to the above-described places, and an optical object is provided on the special pavement. The optical object reflects visible light in a narrow specific frequency band centered on a single frequency of the laser light LR irradiated from the course prediction device 2, and absorbs visible light in a frequency band other than the specific frequency band. have. Examples of the optical object include beads, a sheet-like optical object, a fiber-like optical object, and a chip because of differences in shape and size.

  With reference to FIG.2 and FIG.3, the special paved road surface 3 using the bead 4 is demonstrated. FIG. 2 is an example of an optical object on the special pavement surface of FIG. 1 and is a cross-sectional view of beads. FIG. 3 is a cross-sectional view of a special paved road surface specially paved using the beads of FIG.

  The beads 4 are fine spheres. When the special paved road surface 3 is formed using the beads 4, a large amount of beads 4,... Are mixed in the paint or the like and applied to the surface of the road R as the special paved road surface 3 such as an intersection (see FIG. 3). At this time, the beads 4,... Are distributed evenly over the entire surface of the special paved road surface 3, and are arranged on the surface side of the special paved road surface 3 so that a part of the beads 4 is exposed. The beads 4 include a light absorbing portion 4a, a reflective layer 4b, a high refractive index layer 4c, and a light scattering layer 4d (see FIG. 2).

  The light absorbing portion 4 a is spherical and is disposed at the innermost part of the bead 4. The light absorber 4 is formed of a black material (for example, chromium or carbon) and has a characteristic of absorbing visible light.

  The reflective layer 4b has a spherical shape and is disposed on the surface of the light absorbing portion 4a. The reflective layer 4b has a characteristic of reflecting visible light in a narrow specific frequency band centered on a single frequency of the laser light VR irradiated from the course prediction device 2. Examples of the reflective layer 4b include a hologram coating layer, a metal thin film layer, and a resin layer. The hologram coating layer is formed by coating a hologram material on the surface of the light absorbing portion 4a. At this time, in order to provide a characteristic capable of reflecting visible light in a specific frequency band, an optimal hologram material type and coating thickness are selected. The metal thin film layer is formed by covering the surface of the light absorbing portion 4a with a dielectric metal film. At this time, an optimum metal type and thin film thickness are selected in order to provide a characteristic capable of reflecting visible light in a specific frequency band. The resin layer is formed by alternately stacking two types of polymer materials (resins) having different refractive indexes on the surface of the light absorbing portion 4a. At this time, in order to provide a characteristic capable of reflecting visible light in a specific frequency band, the optimum type of polymer material, the number of layers, and the thickness are selected.

  The high refractive index layer 4c has a spherical shape and is disposed on the outer surface of the reflective layer 4b. The high refractive index layer 4c is formed of a material having a high refractive index, and is an angle at which light incident at various angles can enter the light absorbing portion 4a (desirably, perpendicular or nearly perpendicular to the light absorbing portion 4a). Angle). Since the beads 4 are spherical, the high refractive index layer 4c refracts incident light in the central direction.

  The light scattering layer 4d has a spherical shape and is formed on the outer surface of the high refractive index layer 4c. The light scattering layer 4d is formed of a material having a high light scattering rate (for example, a matte material such as frosted glass), and has a characteristic of scattering light reflected by the reflective layer 4b in various directions.

  In the case of the special paved road surface 3 using the beads 4, when the laser light LR from the course prediction device 2 is incident on each bead 4, the high refractive index layer 4c causes the laser light LR to be refracted toward the center of the bead 4. The light is reliably incident on the reflective layer 4b. In each bead 4, the refracted laser beam LR is reflected by the reflection layer 4b, and the reflected laser beam LR is further scattered in various directions by the light scattering layer 4d. Further, in each bead 4, when visible light VR having a frequency other than the frequency of laser light LR such as sunlight is incident, the visible light VR incident from various directions by the high refractive index layer 4 c is incident on the center direction of the bead 4. So that the light is reliably incident on the reflective layer 4b (that is, the light absorbing portion 4a). In each bead 4, the refracted visible light VR is transmitted by the reflective layer 4b, and the transmitted visible light VR is absorbed by the light absorbing portion 4a. In this way, the laser beam LR is reflected by the beads 4,... And the visible light VR is absorbed, so that the relative intensity ratio of the laser light LR is higher than that of the visible light VR in other frequency bands. Become.

  Next, the special paved road surface 3 using the sheet-like optical object 5 will be described with reference to FIG. FIG. 4 is a perspective view showing another example of the optical object on the special paved road surface of FIG. 1 and a part of the sheet-like optical object.

  The sheet-like optical object 5 has an extremely thin sheet shape and has a size that matches the special paved road surface 3 such as an intersection. When using the sheet-like optical object 5 as the special paved road surface 3, the sheet-like optical object 5 is pasted on the entire road surface as the special paved road surface 3 such as an intersection. The sheet-like optical object 5 includes a light absorption layer 5a, a reflection layer 5b, a high refractive index layer 5c, and a light scattering layer 5d (see FIG. 4).

  The light absorption layer 5 a is an extremely thin sheet having a size matching the special paved road surface 3, and is disposed at the lowermost part of the sheet-like optical object 5. The reflection layer 5b has an extremely thin sheet shape and is disposed on the upper surface of the light absorption layer 5a. The high refractive index layer 5c has an extremely thin sheet shape and is disposed on the upper surface of the reflective layer 5b. The light scattering layer 5d has an extremely thin sheet shape and is disposed on the upper surface of the high refractive index layer 5c. The light absorption layer 5a, the reflection layer 5b, the high refractive index layer 5c, and the light scattering layer 5d are the same materials as the light absorption portion 4a, the reflection layer 4b, the high refractive index layer 4c, and the high refractive index layer 4c of the beads 4, respectively. Formed and each have similar characteristics.

  Also in the case of the special paved road surface 3 using the sheet-like optical object 5, when visible light VR having a frequency other than the frequency of the laser light LR and the laser light LR from the course prediction device 2 is incident on the sheet-like optical object 5, The same action as in the case of the special paved road surface 3 using the beads 4 described above is obtained, the laser beam LR is reflected and scattered in various directions, and the visible light VR is absorbed. In the case of the sheet-like optical object 5, since it is disposed on the entire surface of the special pavement road surface 3, the ratio of reflecting the laser beam LR and the ratio of absorbing the visible light VR are increased, and the laser beam LR is relative to the visible light VR. The light intensity ratio becomes very high. Moreover, when manufacturing the sheet-like optical object 5, compared with the case where the bead 4 is manufactured, it can manufacture comparatively easily.

  Incidentally, by further embossing the sheet-like optical object 5, it becomes easy to reflect the laser light LR incident from the oblique direction, and further to absorb the visible light VR incident from the oblique direction. In the case of the sheet-like optical object 5, since the light absorption layer 5a spreads over a wide range, the incident visible light VR has a high probability of being incident on the light absorption layer 5a, so that the high refractive index layer 5c is not provided. Good.

  Next, the special pavement road surface 3 using the fiber-like optical object 6 will be described with reference to FIG. FIG. 5 is a perspective view showing another example of the optical object on the special pavement surface in FIG. 1 and a part of the fiber-like optical object.

  The fiber-shaped optical object 6 has an extremely fine fiber shape and has a length of an arbitrary side of the special pavement surface 3 such as an intersection. When using the fiber-shaped optical object 6 as the special paved road surface 3, paint, adhesive, etc. are applied to the surface of the road R to be used as the special paved road surface 3 such as an intersection, and a large number of fiber-like optical objects 6, ... are spread at predetermined intervals. At this time, the fiber-like optical objects 6,... Are arranged on the surface side of the special paved road surface 3 so that a part thereof is exposed. The fiber-shaped optical object 6 includes a light absorbing portion 6a, a reflective layer 6b, a high refractive index layer 6c, and a light scattering layer 6d (see FIG. 5).

  The light absorbing portion 6 a is a cylindrical column having a minimum diameter corresponding to the length of one side of the special paved road surface 3, and is disposed at the center of the fiber-like optical object 6. The reflective layer 6b has an extremely thin cylindrical shape and is disposed on the surface of the light absorbing portion 6a. The high refractive index layer 6c has a very thin cylindrical shape and is disposed on the outer surface of the reflective layer 6b. The light scattering layer 6d has an extremely thin cylindrical shape and is disposed on the outer surface of the high refractive index layer 6c. The light absorbing portion 6a, the reflective layer 6b, the high refractive index layer 6c, and the light scattering layer 6d are the same materials as the light absorbing portion 4a, the reflective layer 4b, the high refractive index layer 4c, and the high refractive index layer 4c of the beads 4, respectively. Formed and each have similar characteristics.

  Also in the case of the special paved road surface 3 using the fiber-like optical object 6, when the visible light VR having a frequency other than the frequency of the laser light LR and the laser light LR from the course prediction device 2 is incident on each fiber-like optical object 6. The same action as in the case of the special paved road surface 3 using the beads 4 described above is obtained, and the laser light LR is reflected and scattered in various directions to absorb the visible light VR. Also in the case of the fiber-shaped optical object 6, the ratio of the laser light LR relative to the visible light VR is very high because the ratio of the fiber-shaped optical object 6 to the special paved road surface 3 is high. Further, when the fiber-like optical object 6 is produced, it can be produced relatively easily by first producing a thick fiber-like optical object and stretching it to obtain an ultrafine fiber-like optical object.

  The special pavement surface 3 using chips will be described. The chip is very small and can be generated by finely cutting the sheet-like optical object 5 or the fiber-like optical object 6, for example. When the chip is used as the special paved road surface 3, the same method as that when the beads 4 are used as the special paved road surface 3 is used. In the case of the special paved road surface 3 using this chip, when the visible light VR having a frequency other than the frequency of the laser beam LR or the laser beam LR from the course prediction device 2 is incident on each chip, the beads 4 described above are used. The same action as in the case of the special paved road surface 3 is obtained, the laser light LR is reflected and scattered in various directions, and the visible light VR is absorbed.

  The operation of the road surface drawing system 1 will be described with reference to FIG. Here, a case where the automobile V makes a left turn at an intersection will be described.

  The course prediction device 2 of the automobile V predicts the course according to the driver's steering operation and the like, and forms a shape indicating the predicted course with the laser beam. Then, the course prediction device 2 determines that the course is changed (left turn) from the predicted course, and irradiates the front road surface with the laser beam LR having a predetermined shape.

  When the irradiated laser light LR hits the special paved road surface 3, the special paved road surface 3 reflects the laser light LR and further scatters the reflected laser light LR in various directions. Further, when the visible light VR having a frequency other than the frequency of the laser beam LR (mainly sunlight in the daytime, mainly streetlight or headlight in the nighttime) hits the special pavement surface 3, the special pavement The road surface 3 absorbs the visible light VR. Therefore, on the special pavement road surface 3, the intensity of the laser beam LR is higher than that of the other visible light VR. As a result, the driver of the automobile V, the driver of the other cars around the special paved road surface 3 and the pedestrian can easily recognize the shape formed by the reflected and scattered laser light LR, and the path (left turn) of the automobile V can be determined. You can know in advance.

  According to this road surface description system 1, the visibility of the laser beam LR having a single frequency irradiated on the special paved road surface 3 can be improved, and various shapes formed by the laser beam LR can be easily recognized. Can do. In particular, according to the road surface description system 1, since the laser light LR reflected by the light scattering layer is scattered, the visibility from all directions is improved. Further, according to the road surface description system 1, the visible light VR incident by the high refractive index layer is refracted so as to be surely incident on the light absorbing portion, so that the absorption factor of the visible light VR is improved and the laser light LR is visually recognized. The property is further improved.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  For example, in this embodiment, the present invention is applied to improve the visibility of the laser light emitted from the course prediction device. However, when driving assistance such as garage entry is performed using visible light or road marking is performed using visible light. The present invention is applicable to various road surface drawing systems such as when performing. When applied to road markings, not only for specific shapes, but also when switching speed limits according to weather and traffic conditions, or when switching lane information such as right turn lanes, left turn lanes, straight lanes according to traffic conditions and time zones Can also be supported.

  In this embodiment, special pavement is applied to specific places such as intersections, but special pavement may be given to places where accidents occur frequently, or to all roads as much as possible. Special pavement may be applied. When it is applied to all roads, beads or chips may be mixed in asphalt material or the like at the stage of normal paving, instead of special paving on the ordinary paved road.

  In this embodiment, the present invention is applied to laser light having a single frequency, but other visible light having a narrow frequency band may be used.

  In this embodiment, the light scattering layer is formed integrally with an optical object (such as a bead), but the light scattering layer is formed as a separate bead, chip, sheet-like optical object, or fiber-like optical object. In addition, an optical object having no light scattering layer and an optical object consisting only of the light scattering layer may coexist on the road surface.

It is a lineblock diagram of the road surface description system concerning this embodiment. It is an example of the optical object of the special pavement surface of FIG. 1, and is sectional drawing of a bead. It is sectional drawing of the special paved road surface specially paved using the bead of FIG. It is another example of the optical object of the special pavement surface of FIG. 1, and is a perspective view which shows a part of sheet-like optical object. It is another example of the optical object of the special pavement surface of FIG. 1, and is a perspective view which shows a part of fiber-like optical object.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Road surface description system, 2 ... Track prediction apparatus, 3 ... Special pavement road surface, 4 ... Bead, 4a, 6a ... Light absorption part, 4b, 5b, 6b ... Reflective layer, 4c, 5c, 6c ... High refractive index layer, 4d, 5d, 6d ... light scattering layer, 5 ... sheet-like optical object, 5a ... light absorbing layer, 6 ... fiber-like optical object

Claims (12)

A road surface description system that displays a predetermined shape on a road surface with visible light,
An optical object that reflects visible light in a specific frequency band that is a narrow frequency band near the specific frequency and absorbs visible light in a frequency band other than the specific frequency band is provided on the road surface, and visible light in the specific frequency band is provided on the road surface. A road surface description system characterized by irradiating a vehicle with a predetermined shape. The optical object includes a light absorbing material that absorbs visible light, and a reflective layer that reflects only visible light in the specific frequency band is formed on a light incident side of the light absorbing material. Item 12. The road surface description system according to item 1. The road surface drawing system according to claim 2, wherein the reflective layer is any one of a hologram coating layer, a metal thin film layer, and a resin layer. The road surface drawing system according to claim 2 or 3, wherein the optical object has a high refractive index layer formed on a light incident side of the reflective layer. The road surface drawing system according to any one of claims 2 to 4, wherein the optical object has a light scattering layer formed on a light incident side of the reflective layer or the high refractive index layer. . 5. The road surface description system according to claim 1, wherein a light scattering layer formed separately from the optical object coexists with the optical object on the road surface. 6. . The road surface drawing system according to any one of claims 1 to 6, wherein the optical object is any one of a bead, a chip, a sheet-like object, and a fiber-like object. It has a light absorbing material that absorbs visible light, and a reflection layer that reflects only visible light in a specific frequency band that is a narrow frequency band near a specific frequency is formed on the light incident side of the light absorbing material. An optical object. The optical object according to claim 8, wherein the reflective layer is any one of a hologram coating layer, a metal thin film layer, and a resin layer. The optical object according to claim 8, wherein a high refractive index layer is formed on a light incident side of the reflective layer. The optical object according to any one of claims 8 to 10, wherein a light scattering layer is formed on a light incident side of the reflective layer or the high refractive index layer. The optical object according to any one of claims 8 to 11, wherein the optical object is any one of a bead, a chip, a sheet-like object, and a fiber-like object.

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