Patent ID: 9451213
Filing Date: 2016-09-20
CPC Classification: G01C,G01S,G02B,H04N

Claim Text:
1. A distance measuring apparatus for measuring distance to a measuring target by optically detecting the measuring target, the apparatus comprising: a lens, an optical axis of which has a different orientation from an advancing direction of light incident from the measuring target, the lens being configured to form an image from the incident light, thereby obtaining an image of the measuring target; an imaging relative quantity calculator circuitry configured to calculate an imaging relative quantity by obtaining an imaging position indicative of the position of the image with respect to the lens for each of a plurality of wavelengths possessed by the incident light, the imaging relative quantity being a quantity indicative of a relative relationship between the imaging positions; a storage configured to store correlation information, which is information determined by a chromatic aberration characteristic of the lens and the orientation of the optical axis in order to indicate a correlation between the imaging relative quantity and an object distance; and a distance calculator circuitry configured to calculate the object distance by checking the imaging relative quantity against the correlation information, the distance calculator circuitry is configured to measure the distance to the measuring target based on a relative relationship between the imaging positions for the respective wavelengths, wherein the light is refracted in a refractive index for each wavelength so that the imaging positions of the light are different from each other in a direction perpendicular to the advancing direction of the incident light for each wavelength, the object distance, which is the distance between the lens and the measuring target, is varied so that an incident angle of the light on the lens is made different, the object distance is varied so that an imaging position of light of a single wavelength is also changed, the distance calculator circuitry is configured to obtain a difference between the imaging positions for the respective wavelengths based on the chromatic aberration by detecting the imaging positions for the respective wavelengths through a common lens by using light having a wavelength that is not subjected to the chromatic aberration correction for the measurement of the distance.