DISTANCE MEASURING APPARATUS AND LIGHT EMITTING DEVICE FOR DISTANCE MEASUREMENT
A distance measuring apparatus includes: plural light emitters that irradiate a target whose distance is to be measured with light and are arranged along a predetermined first direction; an optical unit that directs light so that in a case where one light emitter emits light, a light amount corresponding to a central part of the light emitter and a light amount of a boundary part with an adjacent light emitter are different and in a case where plural light emitters emit light, the light amount corresponding to the central part of the light emitter and the light amount corresponding to the boundary part are equal; a light emission control unit that controls ON and OFF of the light emitters, the light emission control unit controlling the light emitters in modes including a first lighting mode in which a combination of two or more light emitters along the first direction that is ON and a combination of two or more light emitters along the first direction that is OFF alternate, a first inversion mode in which ON and OFF are reverse to those in the first lighting mode, a second lighting mode in which a combination of two or more light emitters that is ON and a combination of two or more light emitters that is OFF alternate, the combination in the second lighting mode being shifted by at least one light emitter from the combination in the first lighting mode in the first direction, and a second inversion mode in which ON and OFF are reverse to those in the second lighting mode; and a distance measurement unit that, in a case where plural light receiving regions are provided corresponding to each of the light emitters along the first direction in a region where a light receiving unit receives light from the target, performs distance measurement on a basis of a light reception result in the first lighting mode and a light reception result in the first inversion mode in a light receiving region excluding a light receiving region corresponding to a first boundary part located at a boundary between ON and OFF in the first lighting mode, and performs distance measurement on a basis of a light reception result in the second lighting mode and a light reception result in the second inversion mode in a light receiving region excluding a light receiving region corresponding to a second boundary part located at a boundary between ON and OFF in the second lighting mode.
1 . A distance measuring apparatus comprising:
a plurality of light emitters that irradiate a target whose distance is to be measured with light and are arranged along a predetermined first direction;
an optical unit that directs light so that in a case where one light emitter emits light, a light amount corresponding to a central part of the light emitter and a light amount of a boundary part with an adjacent light emitter are different and in a case where a plurality of light emitters emit light, the light amount corresponding to the central part of the light emitter and the light amount corresponding to the boundary part are equal;
a light emission control unit that controls ON and OFF of the light emitters, the light emission control unit controlling the light emitters in modes including a first lighting mode in which a combination of two or more light emitters along the first direction that is ON and a combination of two or more light emitters along the first direction that is OFF alternate, a first inversion mode in which ON and OFF are reverse to those in the first lighting mode, a second lighting mode in which a combination of two or more light emitters that is ON and a combination of two or more light emitters that is OFF alternate, the combination in the second lighting mode being shifted by at least one light emitter from the combination in the first lighting mode in the first direction, and a second inversion mode in which ON and OFF are reverse to those in the second lighting mode; and
a distance measurement unit that, in a case where a plurality of light receiving regions are provided corresponding to each of the light emitters along the first direction in a region where a light receiving unit receives light from the target, performs distance measurement on a basis of a light reception result in the first lighting mode and a light reception result in the first inversion mode in a light receiving region excluding a light receiving region corresponding to a first boundary part located at a boundary between ON and OFF in the first lighting mode, and performs distance measurement on a basis of a light reception result in the second lighting mode and a light reception result in the second inversion mode in a light receiving region excluding a light receiving region corresponding to a second boundary part located at a boundary between ON and OFF in the second lighting mode.
2 . The distance measuring apparatus according to claim 1 , wherein:
in the first lighting mode, a first unit of light emission that is ON and a first unit of light emission that is OFF alternate in the first direction, the first unit of light emission being the combination of two or more light emitters along the first direction; and
in the second lighting mode, a second unit of light emission that is ON and a second unit of light emission that is OFF alternate in the first direction, the second unit of light emission being the combination of light emitters shifted by one light emitter from the first unit of light emission in the first direction.
3 . The distance measuring apparatus according to claim 1 , wherein:
the plurality of light emitters includes a plurality of light emitters arranged along a second direction that crosses the first direction.
4 . The distance measuring apparatus according to claim 3 , wherein:
the light emission control unit controls the light emitters in the modes including a third lighting mode in which a combination of two or more light emitters that is ON and a combination of two or more light emitters that is OFF alternate, the combination in the third lighting mode being shifted by at least one light emitter from the combination in the first lighting mode in the second direction, a third inversion mode in which ON and OFF are reverse to those in the third lighting mode, a fourth lighting mode in which a combination of two or more light emitters that is ON and a combination of two or more light emitters that is OFF alternate, the combination in the fourth lighting mode being shifted by at least one light emitter from the combination in the first lighting mode in the first direction and the second direction, and a fourth inversion mode in which ON and OFF are reverse to those in the fourth lighting mode; and
the distance measurement unit performs distance measurement on a basis of a light reception result in the third lighting mode and a light reception result in the third inversion mode in a light receiving region excluding a light receiving region corresponding to a third boundary part located at a boundary between ON and OFF in the third lighting mode, and performs distance measurement on a basis of a light reception result in the fourth lighting mode and a light reception result in the fourth inversion mode in a light receiving region excluding a light receiving region corresponding to a fourth boundary part located at a boundary between ON and OFF in the fourth lighting mode.
5 . The distance measuring apparatus according to claim 4 , wherein:
in the third lighting mode, a third unit of light emission that is ON and a third unit of light emission that is OFF alternate in the second direction, the third unit of light emission being the combination of light emitters shifted by one light emitter from the first unit of light emission in the second direction; and
in the fourth lighting mode, a fourth unit of light emission that is ON and a fourth unit of light emission that is OFF alternate in the first direction and the second direction, the fourth unit of light emission being the combination of light emitters shifted by one light emitter from the third unit of light emission in the first direction.
6 . The distance measuring apparatus according to claim 1 , wherein:
the light receiving unit includes a light receiver that generates a charge upon receipt of light, a first capacitor that is connected to the light receiver and is capable of accumulating a charge, a second capacitor that is connected in parallel to the first capacitor and is capable of accumulating a charge, and a switch that switches a connection destination of the light receiver between the first capacitor and the second capacitor; and
the distance measurement unit performs distance measurement on a basis of a charge amount accumulated in the first capacitor and a charge amount accumulated in the second capacitor that are a light reception result.
7 . The distance measuring apparatus according to claim 6 , wherein:
in a case where the light emitters are repeatedly turned on and off at predetermined first time intervals, the distance measurement unit performs distance measurement on a basis of a charge amount from which a charge amount accumulated during a non-light-emission state has been subtracted on a basis of a light reception result measured by switching the switch in accordance with the first time intervals and a light reception result measured by switching the switch at time intervals whose phase is shifted from the first time intervals.
8 . The distance measuring apparatus according to claim 6 , wherein:
the distance measurement unit performs distance measurement on a basis of a light reception result obtained in a case where the light emitters are repeatedly turned on and off at predetermined first time intervals and a light reception result obtained in a case where the light emitters are repeatedly turned on and off at second time intervals different from the first time intervals.
9 . A light emitting device for distance measurement that outputs light for distance measurement for measuring a distance to a target on a basis of light from the target, comprising:
a plurality of light emitters that irradiate the target with light and are arranged along a predetermined first direction;
an optical unit that directs light so that in a case where one light emitter emits light, a light amount corresponding to a central part of the light emitter and a light amount of a boundary part with an adjacent light emitter are different and in a case where a plurality of light emitters emit light, the light amount corresponding to the central part of the light emitter and the light amount corresponding to the boundary part are equal; and
a light emission control unit that controls ON and OFF of the light emitters, the light emission control unit controlling the light emitters in modes including a first lighting mode in which a combination of two or more light emitters along the first direction that is ON and a combination of two or more light emitters along the first direction that is OFF alternate, a first inversion mode in which ON and OFF are reverse to those in the first lighting mode, a second lighting mode in which a combination of two or more light emitters that is ON and a combination of two or more light emitters that is OFF alternate, the combination in the second lighting mode being shifted by at least one light emitter from the combination in the first lighting mode in the first direction, and a second inversion mode in which ON and OFF are reverse to those in the second lighting mode.
10 . A distance measuring apparatus comprising:
a plurality of light emitting means for irradiating a target whose distance is to be measured with light, the plurality of light emitting means being arranged along a predetermined first direction;
optical means for directing light so that in a case where one light emitting means emits light, a light amount corresponding to a central part of the light emitting means and a light amount of a boundary part with an adjacent light emitting means are different and in a case where a plurality of light emitting means emit light, the light amount corresponding to the central part of the light emitting means and the light amount corresponding to the boundary part are equal;
light emission control means for controlling ON and OFF of the light emitting means, the light emission control means controlling the light emitting means in modes including a first lighting mode in which a combination of two or more light emitting means along the first direction that is ON and a combination of two or more light emitting means along the first direction that is OFF alternate, a first inversion mode in which ON and OFF are reverse to those in the first lighting mode, a second lighting mode in which a combination of two or more light emitting means that is ON and a combination of two or more light emitting means that is OFF alternate, the combination in the second lighting mode being shifted by at least one light emitting means from the combination in the first lighting mode in the first direction, and a second inversion mode in which ON and OFF are reverse to those in the second lighting mode; and
distance measurement means for, in a case where a plurality of light receiving regions are provided corresponding to each of the light emitting means along the first direction in a region where light receiving means receives light from the target, performing distance measurement on a basis of a light reception result in the first lighting mode and a light reception result in the first inversion mode in a light receiving region excluding a light receiving region corresponding to a first boundary part located at a boundary between ON and OFF in the first lighting mode, and performing distance measurement on a basis of a light reception result in the second lighting mode and a light reception result in the second inversion mode in a light receiving region excluding a light receiving region corresponding to a second boundary part located at a boundary between ON and OFF in the second lighting mode.