Color toner density sensor and image forming apparatus using the same

摘要

In an image forming apparatus, a toner density sensor has a light emitting element from emitting light toward a toner pattern image formed on an image carrier, and a light receiving element for receiving the resulting reflection from the image. The light emitting element and light receiving element each has a directivity. The optical axes of the light emitting element and light receiving element intersect each other at a point exiting on or in the vicinity of the surface of the image carrier. The light emitting and light receiving elements are positioned such that a plane containing their optical axes is inclined a predetermined angle relative to a normal extending from the surface of the image carrier through the above point.