Distance measuring apparatus

• US 4,582,424 A
• Filed: 05/12/1983
• Issued: 04/15/1986
• Est. Priority Date: 05/20/1982
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kawabata, Takashi
• Primary Examiner(s): Buczinski, S. C.
• Assistant Examiner(s): Koltak, Melissa Q.
• Application Number:
  US06/493,975
• Time in Patent Office: 1,069 Days
• Field of Search: 356/1, 354/403
• US Class Current: 356/3.01
• CPC Class Codes: G01C 3/10 using a parallactic triangle with variable angles and a base of fixed length in the observation station, e.g. in the instrument

Abstract

A distance measuring apparatus provided with a plurality of light-emitting units and a plurality of light-receiving units. The light emission period of each of the light-emitting units is changed over at each predetermined period interval. A plurality of light-receiving elements constituting each light-receiving unit are constructed so as to receive the reflected light from a plurality of distance measurement fields of view on an object to be photographed in a plurality of distance measurement zones obtained by dividing a range to be measured into several blocks. The input signal from each of the light-receiving elements in each of the distance measurement zones is changed over in synchronism with the light emission period of the light-emitting units and the output signals for the respective distance measurement zones are compared, whereby a distance data indicative of the distance measurement zone most approximate to the object distance is put out.

Claims

1. A distance measuring apparatus comprising:

(a) a plurality of light-emitting means emitting light at a predetermined period interval, said light-emitting means projecting the light onto a plurality of distance measurement fields of view of an object to be photographed whose distance is to be measured;

(b) light-receiving means comprising a plurality of light-receiving elements for receiving the reflected light from said object, said light-receiving elements receiving the reflected light from a plurality of distance measurement fields of view on said object in distance measurement zones obtained by dividing a distance measurement range into several blocks;

(c) a signal detecting circuit having change-over means for receiving as input the output signals of said light-receiving elements having received the reflected light from said distance measurement field of view in each of said distance measurement zones and for time-divisionally changing over the output signal from each of said light-receiving elements in each of said distance measurement zones;

(d) signal output means for receiving as input the signal of said signal detecting circuit for each of said distance measurement zones and putting out a signal from the distance measurement zone most approximate to the object distance; and

(e) means for putting out a distance data, said means receiving as input the signal of said output means and putting out the distance data.