| 摘要 |
PROBLEM TO BE SOLVED: To provide a color density detector with a simple constitution, capable of optically detecting the quantity of color toner stuck onto an image carrier (surface density), with high accuracy, especially, in a high-sticking region such as a region where the surface of the image carrier is completely covered with toner. SOLUTION: Both of a light emitting element 2 and a light receiving element 3 have directivity. These light emitting and receiving elements 2 and 3 are disposed to place a point P where the optical axes of the light emitting and receiving elements 2 and 3 intersect each other, on the surface of the image carrier 4C or in its vicinity and be at an angle ψ formed in such a manner that an optical axial plane S1 including both optical axes of the light emitting and receiving elements 2 and 3 is inclined with respect to a normal h from the surface of the image carrier 4C passing through the intersection P by a fixed angle. |
