US 5,317,375 A · Optical distance measuring apparatus

Abstract

An optical distance measuring apparatus operable in accordance with an optical intensity modulating process to optically measure a distance between a driver's vehicle and a vehicle running ahead of his vehicle includes a light emitting portion serving as a light source to emit a distance measuring light beam, an optical lens system, a light receiving portion for receiving a reflected light reflected from the vehicle running ahead of the driver's vehicle through the optical lens system, and a processing system for correcting phase delay between the distance measuring light beam and the reflected light beam utilizing reference light beams emitted from a plurality of reference light sources to determine the distance. A processing system for determining the distance based on a time difference between the time when the distance measuring light beam is emitted from the light emitting portion and the time when the reflected light beam is received by the light receiving portion may be substituted for the processing system for the correcting phase delay between the distance measuring light beam and the reflected light beam. In addition, the system includes an apparatus for mounting on a vehicle body optical distance measuring apparatuses, each operable as a light emitting/receiving portion.

Claims11

Dependent claims

An optical distance measuring apparatus operable, comprising:

a light emitting means for emitting a distance measuring light beam,
an optical lens system including means for orienting said distance measuring light beam toward an object to be measured, said distance measuring light beam being reflected from said object in the form of a reflected light beam,
light receiving means for receiving a reflected light beam reflected from said object to be measured through said optical lens system,
a plurality of reference light source means, each arranged in optical association with said light receiving means for generating a reference light beam, and
processing means for correcting a phase delay between said distance measuring light beam and said received reflected light beam using said reference light beams so as to determine a distance, said processing means including a display portion having a screen, and
control means for performing a controlling operation such that a certain item representing a distance is visually recognized on the screen of said display portion only when said object to be measured is present within a range where said distance can be measured with said apparatus.

3 more elements

Dependencies are inferred from the claim text.

Optical distance measuring apparatus

Life of this patent

Optical distance measuring apparatus

Life of this patent

Abstract

Claims11