Optical scanning apparatus

• US 6,246,502 B1
• Filed: 11/30/1999
• Issued: 06/12/2001
• Est. Priority Date: 11/30/1998
• Status: Expired due to Fees

• Current Assignee: Mindspeed Technologies Inc. (MACOM Technology Solutions Holdings, Inc.)
• Original Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Inventors: Yoshikawa, Toshihiko, Okada, Tohru, Takayama, Munehiro
• Primary Examiner(s): SCHUBERG, DARREN E
• Application Number:
  US09/451,143
• Time in Patent Office: 560 Days
• Field of Search: 359/196, 359/197, 359/204, 340/435, 340/436, 356/3.09
• US Class Current: 359/196.1
• CPC Class Codes: G02B 26/127 Adaptive control of the scanning light beam, e.g. using the feedback from one or more detectors G02B27/0031 takes precedence

Abstract

An optical scanning apparatus RD scans a laser beam and detects a foregoing vehicle FC present in a forward direction by a reflected beam derived from the laser beam. The apparatus includes a first mode for emitting a narrowed laser beam and a widened laser beam and a second mode for emitting the widened laser beam and the two modes are switched to thereby provide an apparatus for emitting a beam capable of detecting an object in a wide range, causing no detection failure and in compliance with a situation of surrounding objects.

Claims

1. An optical scanning apparatus for emitting a scanning laser beam in a forward direction for detecting an object in the forward direction by a reflected beam derived from the laser beam, said optical scanning apparatus including:

a first mode for emitting a narrowed laser beam and a widened laser beam; and

a second mode of emitting the widened laser beam;

wherein the first mode and the second mode are periodically switched.

2. The optical scanning apparatus according to claim 1:

wherein the first mode and the second mode are switched by detecting a distance between the apparatus and the object from information derived from the reflected beam or advance of the object into a range of emitting the laser beam or departure thereof to outside of the range.

3. The optical scanning apparatus according to claim 2:

wherein the first mode is utilized when the distance between the apparatus and the object is equal to or smaller than a first predetermined distance or equal to or larger than a second predetermined distance and the second mode is utilized when the distance between the apparatus and the object falls in a range between the first predetermined distance and the second predetermined distance.