| 摘要 |
PURPOSE:To obtain a detector with high sensitivity and low cost for reducing internal disturbance light by providing a window member having a partition against a light emitting element and a light receiving element at a position opposite to an object to be detected of a case. CONSTITUTION:A shielding window member 3 in common use is provided for protecting a light emitting element 1 and a light receiving element 2 from contamination such as toner. In addition a lining plate 5 for partitioning the elements 1, 2 inside the same case is provided and also a partition 6 is provided at the center of the window member 6. Near infrared light emitted from the light emitting element 3 transmits through the window member 3, reaches the toner which is to be detected, is reflected there and further transmits through the window member 3 to be incident to the light receiving element 2. Since the partition 6 is molded by extending the lining plate 5 which partitions between the elements 1, 2 by several mm and assembling on a cut 3a of the window member 3, linear light from the element 1 is prevented from being reflected inside and entering the element 2. |
