Optical distance measuring device and printing apparatus using the same
AssigneeSharp Kabushiki Kaisha
InventorsAkifumi Yamaguchi, Hisakazu Sugiyama
Life of this patent
Estimating the term…
Abstract
An optical distance measuring device has an objective lens that condenses light from a light emission element to irradiate a measuring object and to form on the measuring object a light spot having a diameter not smaller than 10 μm and not larger than 30 μm. A light receiving lens condenses light reflected from the light spot on the measuring object to make the light incident on a photodetector through a pinhole having a diameter not smaller than 10 μm and not larger than 50 μm. With movement of the measuring object, detection signal of which an amplitude and an output level change according to a distance to the measuring object is obtained from the photodetector.
Claims10
An optical distance measuring device comprising
- an objective lens for condensing light emitted from a light emission element, irradiating a surface of a measuring object that is moving which surface extends along a moving direction of the measuring object, and forming a light spot on the surface of the measuring object,
- a light receiving lens for condensing light reflected from the light spot formed on the measuring object,
- a pinhole-formed body where a pinhole is formed that allows passage of the light condensed by the light receiving lens,
- a photodetector on which the light having passed through the pinhole is incident and which outputs light reception signal in response to a quantity of the light, and
- distance measuring means for measuring a distance to the measuring object on basis of the light reception signal from the photodetector.
Dependencies are inferred from the claim text.