Patent ID: 11934134
Assignee: TOSHIBA TEC KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 16:
17. An image forming apparatus, comprising:
an image forming unit to form an image on a sheet;
a sensor including a light emitting part with a light emission intensity that changes according to an input voltage level and a light receiving part that outputs an output value that changes according to the amount of incident light, the sensor configured to detect a toner density of the image formed by the image forming unit;
a power supply unit to supply power to the light emitting part and change the input voltage level of the power supplied to light emitting part in a predetermined sequence until an end condition is satisfied during an inspection operation; and
a controller configured to make an abnormality determination based on a state of the sensor when the end condition is satisfied during the inspection operation, wherein
the image forming unit includes a transfer belt on which a toner image is formed before transfer to the sheet,
the sensor is positioned to detect the toner density of the image formed by the image forming unit by inspection of the toner image on the transfer belt before transfer to the sheet,
the controller is further configured to determine whether or not the transfer belt is abnormal based on the output value from the light receiving part when the end condition is satisfied in the inspection operation, and
the controller is further configured to determine that the transfer belt is abnormal when the output value from the light receiving part is outside a output target range and the input voltage level is within an input target range when the end condition is satisfied during the inspection operation.