US 7,545,485 B2
Laser radar apparatus that measures direction and distance of an object
Masanori Okada, Kariya (Japan); Koji Konosu, Kariya (Japan); and Hideyuki Tanaka, Toyoake (Japan)
Assigned to Denso Wave Incorporated, Tokyo (Japan)
Filed on Feb. 05, 2008, as Appl. No. 12/68,258.
Claims priority of application No. 2007-293224 (JP), filed on Nov. 12, 2007.
Prior Publication US 2009/0122294 A1, May 14, 2009
Int. Cl. G01C 3/08 (2006.01)
U.S. Cl. 356—4.01  [356/5.01] 9 Claims
OG exemplary drawing
 
1. A laser radar apparatus that measures the distance of an object and the direction to the object, the object being located in a measurement range from the laser radar apparatus, comprising:
laser beam generating means for generating a laser beam having an axis thereof and emitting the laser beam toward the measurement range;
photo detecting means for detecting a reflected laser beam that is reflected back by the object located in the measurement range;
a mirror assembly comprising:
a through-hole that pierces the mirror assembly being coaxial with the axis of the laser beam emitted from the laser beam generating means and transmits the laser beam emitted from the laser beam generating means; and
a reflecting surface that is arranged to be at a predetermined angle to the axis of the laser beam emitted from the laser beam generating means and reflects a reflected laser beam reflected back by the object toward the photo detecting means;
light deflecting means for deflecting the laser beam emitted from the laser beam generating means and deflecting the laser beam reflected back by the object located in the measurement range, the light deflecting means having a rotation axis and a focal point thereof and comprising a mirror surface including a flat reflecting portion having a flat mirror surface and a concave reflecting portion having a concave-shaped mirror surface;
rotation driving means for rotating the light deflecting means around the rotation axis of the light deflecting means such that both the concave-shaped mirror surface of the concave reflecting portion and the flat mirror surface of the flat reflecting portion of the light deflecting means are turned to be in the direction of the measurement range,
wherein the focal point of the light deflecting means is located on the rotation axis of the light deflecting means, and
the light deflecting means deflects the laser beam emitted from the laser beam generating means toward the measurement range and deflecting the laser beam reflected back by the object located in the measurement range toward the mirror assembly.