主权项 |
1. A fuser device comprising:
a heating member heated by heating means; a pressure-applying member that presses against the heating member and forms a nip; a first drive part having a first motor for rotatably driving one of the heating member and the pressure-applying member; a pressure-application-switching mechanism capable of switching between a state in which pressure is applied to the nip and a state in which the pressure on the nip is released; a second drive part having a second motor rotating either in a forward direction or a reverse direction in order to switch the pressure-application-switching mechanism between the applied-pressure state and the released-pressure state; a first detector for detecting whether the first drive part is rotating; and a second detector for detecting the forward-direction or reverse-direction rotation of the second drive part; the first detector having a first detector plate, on which are disposed in the circumferential direction a plurality of first slits capable of transmitting light, the first detector plate being provided on a first rotating member caused to rotate by the first motor; and a sensor, on which are disposed a light-emitting part for emitting light and a light receiving part for receiving light emitted by the light-emitting part, the sensor adapted for detecting the rotation of the first drive part by detecting, using the light receiving part, the light emitted from the light-emitting part as light pulses; and the second detector having a second detector plate, on which is disposed at a predetermined position in the circumferential direction a second slit capable of transmitting light, the second detector plate provided on a second rotating member caused to rotate in the forward and reverse directions by the second motor; the second detector adapted for detecting, when the pressure-application-switching mechanism is in the applied-pressure state or the released-pressure state, whether the nip is in the applied-pressure state or the released-pressure state by detecting, using the light receiving part, changes in the light-reception status of the light emitted by the light-emitting part for a predetermined period of time as the second detector plate rotates. |