Optical detection apparatus and method for determining optical axis misalignment in optical detection apparatus
An optical detection apparatus is provided. The optical detection apparatus includes a light emitting unit, a light receiving unit, a storage unit, and a determining unit. The light emitting unit includes a plurality of light-emitting elements. The light receiving unit includes a light-receiving element arrayformed by a plurality of light-receiving pixels, which receive reflected light corresponding to emitted light of the light emitting unit. The storage unit stores a reference light-receiving region on the light-receiving element array corresponding to a location of occurrence of light intensity unevenness included in the emitted light of the light emitting unit. The determining unit determines an optical axis misalignment using a positional displacement between the reference light-receiving region and a detected light-receiving region of light intensity unevenness included in the reflected light of the emitted light on the light-receiving element array.
1 . An optical detection apparatus comprising:
a light emitting unit including a plurality of light-emitting elements;
a light receiving unit including a light-receiving element array formed by a plurality of light-receiving pixels, the light-receiving pixels receiving reflected light corresponding to emitted light of the light emitting unit;
a storage unit configured to store a reference light-receiving region on the light-receiving element array corresponding to a location of occurrence of light intensity unevenness included in the emitted light of the light emitting unit; and
a determining unit configured to determine an optical axis misalignment using a displacement between the reference light-receiving region and a detected light-receiving region of light intensity unevenness included in the reflected light of the emitted light on the light-receiving element array, the light intensity unevenness being formed due to a difference in emission intensities caused by an overlapped region where irradiated regions of light emitted from the plurality of light-emitting elements overlap, wherein
the determining unit is configured to determine the optical axis misalignment based on a comparison between a location of the detected light-receiving region corresponding to the overlapped region and a location of the reference light-receiving region corresponding to the location of occurrence of the light intensity unevenness.
2 . The optical detection apparatus according to claim 1 , wherein
the plurality of light-receiving pixels are arranged without a gap in an arrangement direction of the plurality of light-emitting elements so as to receive the light intensity unevenness included in the reflected light by the plurality of light-receiving pixels.
3 . The optical detection apparatus according to claim 1 , wherein
the plurality of light-receiving pixels are arranged without a gap in a direction orthogonal to an arrangement direction of the plurality of light-emitting elements so as to receive the light intensity unevenness included in the reflected light by the plurality of light-receiving pixels.
4 . The optical detection apparatus according to claim 1 , wherein
each of the plurality of light-receiving pixels has a dimension such that the light intensity unevenness included in the reflected light is received by the plurality of light-receiving pixels.
5 . The optical detection apparatus according to claim 1 , wherein
the determining unit is configured to determine the detected light-receiving region using a difference between a light intensity of the light intensity unevenness and a light intensity of the reflected light.
6 . The optical detection apparatus according to claim 5 , wherein
the determining unit is configured to learn the difference using the light intensity of the light intensity unevenness and the light intensity of the reflected light.
7 . The optical detection apparatus according to claim 2 , wherein
the determining unit is configured to:
determine that an optical axis misalignment has occurred when an amount of displacement between the reference light-receiving region and the detected light-receiving region is greater than a predetermined first determination value; and
execute a process for notifying of the optical axis misalignment.
8 . The optical detection apparatus according to claim 7 , wherein
the determining unit is configured to:
calculate a predicted time at which an optical axis misalignment will occur when the amount of displacement between the reference light-receiving region and the detected light-receiving region is greater than a predetermined second determination value, the second determination value being smaller than the first determination value.
9 . The optical detection apparatus according to claim 1 , wherein
the determining unit is configured to:
calculate a predicted time at which an optical axis misalignment will occur when an amount of displacement between the reference light-receiving region and the detected light-receiving region is greater than a predetermined second determination value, the second determination value being smaller than a first determination value, the first determination value being a determination value of an optical axis misalignment.