| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately detect fluidity of developer in non-contact with the developer. <P>SOLUTION: A developing device having conveyance screws 16 and 17 conveying the developer 13 includes: a light emitting element 21 and a light receiving element 22 which are paired and arranged so that output light 20 may pass through a space part between screw blades 16b and 17b adjacent when cross-sectioning the conveyance screws 16 and 17 in an axial direction; and a detection means which integrates ON time during which the light receiving element 22 receives the output light 20 from the light emitting element 21 for a predetermined time during driving the conveyance screws 16 and 17 and detection output of the light receiving element 22 becomes ON, and which detects the fluidity of the developer 13 based on a ratio of the ON time to the predetermined time. <P>COPYRIGHT: (C)2010,JPO&INPIT |
