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US 9,812,270 B2Granted
Interlock circuit and image forming apparatus
AssigneeKYOCERA Document Solutions Inc.
InventorRyo Takayama
Life of this patent
Estimating the term…
Abstract
An interlock switch is turned on to close a power supply line when a cover is closed, and turned off to open the power supply line when the cover is opened. A time constant circuit is connected to a node side of the interlock switch in the power supply line. A switch control unit determines that a user is intentionally turning on and off the interlock switch and turns off a switch Q1 when a smoothed voltage obtained by smoothing a voltage difference between voltage dividing nodes becomes larger than a threshold value.
Claims5
An interlock circuit, comprising:
- a power supply line configured to supply a direct-current voltage supplied from a power supply unit to a load;
- an interlock switch configured to open and close the power supply line, and including a first node at a side of the power switch unit and a second node at a side of the load;
- a time constant circuit connected to the second node in the power supply line and configured to delay a response of a power supply voltage to be applied to the power supply line when the interlock switch closes the power supply line;
- a first switch connected between the time constant circuit and the load;
- and
- a switch control unit configured to smooth a voltage difference between the first node and the second node and turn off the first switch when an obtained smoothed voltage becomes larger than a threshold value.
3 more elements
Dependencies are inferred from the claim text.