US 12,436,282 B2
Distance measuring device
Hiroshi Kubota, Yokohama Kanagawa (JP); and Nobu Matsumoto, Ebina Kanagawa (JP)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (JP)
Filed by KABUSHIKI KAISHA TOSHIBA, Tokyo (JP)
Filed on Aug. 31, 2021, as Appl. No. 17/446,611.
Claims priority of application No. 2020-157620 (JP), filed on Sep. 18, 2020.
Prior Publication US 2022/0091262 A1, Mar. 24, 2022
Int. Cl. G01S 17/10 (2020.01); G01S 7/481 (2006.01); G01S 7/4865 (2020.01); G01S 7/487 (2006.01); G01S 17/42 (2006.01); G01S 17/894 (2020.01); G01S 17/931 (2020.01)
CPC G01S 17/10 (2013.01) [G01S 7/4865 (2013.01); G01S 7/487 (2013.01); G01S 17/42 (2013.01); G01S 17/931 (2020.01)] 15 Claims
OG exemplary drawing
 
1. A distance measuring device comprising:
a light emitter including a light source configured to emit an optical signal;
a light receiver including a light detector and an optical system, wherein the optical system is configured to guide reflected light to the light detector, and the reflected light is the optical signal emitted from the light emitter and reflected by an external object;
a measurement section configured to calculate a distance value from the object using a first time and a second time, wherein the first time is a time at which the light source emits the optical signal, and the second time is a time at which the light detector detects the reflected light; and
a controller configured to cause the light source to intermittently emit the optical signal, and cause the measurement section to calculate a distance value for each intermittently emitted optical signal, wherein
the measurement section is configured to:
receive a first digital signal and a second digital signal from the light receiver, wherein the first digital signal includes a light reception result of reflected light of a first optical signal emitted in a first direction, the first digital signal includes a first bottom portion and a first portion protruding from the first bottom portion, the second digital signal includes a light reception result of reflected light of a second optical signal emitted in a second direction different from the first direction, and the second digital signal includes a second bottom portion and a second portion protruding from the second bottom portion;
generate a weighted value based on a degree of similarity of values of the first and second portions, or a degree of similarity of values of the first and second bottom portions;
generate a third digital signal obtained by adding the second digital signal to the first digital signal based on the weighted value, and the third digital signal including a third bottom portion and a third portion protruding form the third bottom portion;
calculate a distance value from an object existing in the first direction by calculating the second time associated with the first optical signal based on a position of the third portion;
divide the first digital signal into a plurality of first periods, and the second digital signal into a plurality of second periods;
calculate a difference between a maximum value and a minimum value in each of the first and second periods; and
use an average value of the difference calculated in each of the first periods as the value of the first bottom portion, and an average value of the difference calculated in each of the second periods as the value of the second bottom portion.