Guide marker and visual guide marker device

DETAILED DESCRIPTION To overcome the problems described above, preferred embodiments of the present invention provide a guide marker for use in AHS, in which an obstacle is detected by a vehicle-mounted radar, that is, a guide marker in which a reflecting direction of incoming radio waves is not limited to a specific direction, and a visual guide marker device for performing guiding reflection of radio waves radiated from a vehicle-mounted radar as well as visual guiding for a driver.
According to a preferred embodiment of the present invention, a guide marker includes a radio-wave reflecting unit for reflecting radio waves in an incident direction of the radio waves, the radio-wave reflecting unit being provided on the surface of a substrate.
The radio-wave reflecting unit reflects the radio waves in at least two incident directions.
Preferably, the radio-wave reflecting unit includes a concave portion and a convex portion integrally provided in the substrate.
Each of the concave and convex portions are preferably substantially hemispherical.
Alternatively, each of the concave and convex portions may extend almost linearly.
The radio-wave reflecting unit and the substrate are preferably made of metal or ceramic.
With this arrangement, incident radio waves are reflected at certain intensity in all directions in a virtual plane, including the incident directions.
Therefore, even when radio waves come from various unspecified directions, that is, even when the incident direction of the radio waves is changed, the reflecting direction of the radio waves is not specified.
The radio-wave reflecting unit preferably includes radio-wave reflectors which resonate at the frequency of incident radio waves and which reflect the radio waves in the incident direction, and the radio-wave reflectors may be mounted on the substrate.
A plurality of the radio-wave reflectors are preferably aligned in rows, and the pitches of the radio-wave reflectors in each row are preferably different from each other.
A plurality of the radio-wave reflectors may be aligned in rows, and the pitch d of the radio-wave reflectors in each row is defined by an expression: d=