Motor control apparatus with controlled input current
AssigneeCanon Kabushiki Kaisha
InventorManabu Mizuno
Life of this patent
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Abstract
A motor control apparatus which is capable of controlling driving currents for stepping motors with efficiency. A feedback stepping motor drives sheet feed rollers located most upstream on a sheet conveying path out of a plurality of rollers. A normal stepping motor drives sheet feed rollers located downstream on the sheet conveying path out of the plurality of rollers. A maximum current value required by the feedback stepping motor when a sheet is conveyed is detected. A driving current value for the normal stepping motor is set to a value according to the maximum current value before the sheet enters the downstream sheet feed rollers after passing the upstream sheet feed rollers.
Claims10
An image forming apparatus comprising:
- an image forming unit that forms an image on a sheet;
- a sheet conveying path;
- a first motor for driving a first roller located on the sheet conveying path, said first roller conveying a sheet;
- a second motor for driving a second roller located at a location downstream of said first roller on said sheet conveying path, said second roller conveying the sheet conveyed by said first rooler;
- a first detecting device that detects a rotation of said first motor;
- a first control device that controls a driving current value for said first motor in accordance with a detection result of said first detecting device;
- a second detecting device that detects a maximum current value required by said first motor to drive said first roller when the sheet is conveyed by said first roller;
- and
- a second control device that controls a driving current value for said second motor in accordance with the maximum current value detected by said second detecting device.
A motor control apparatus comprising:
- a first motor for driving a first roller located on a sheet conveying path, said first roller conveying a sheet;
- a second motor for driving a second roller located at a location downstream of said first roller on said sheet conveying path, said second roller conveying the sheet conveyed by said first roller;
- a first detecting device that detects a rotation of said first motor;
- a first control device that controls a driving current value for said first motor in accordance with a detection result of said first detecting device;
- a second detecting device that detects a maximum current value required by said first motor to drive said first roller when the sheet is conveyed by said first roller;
- and
- a second control device that controls a driving current value for said second motor in accordance with the maximum current value detected by said second detecting device.
Dependencies are inferred from the claim text.