Sheet size detecting apparatus responsive to a conveying speed of the sheet
AssigneeCanon Kabushiki Kaisha
InventorsWataru Kawata, Akimaro Yoshida
Life of this patent
Estimating the term…
Abstract
A sheet size detecting apparatus includes a rotary member for conveying a sheet rotation detector together with the rotary member for generating a pulse, a sheet size measurement control device including an arm provided in a vicinity of the rotary member to effect reciprocally rocking by the passing of the front end and the rear end of the sheet. The sheet size measurement control device measures the size of the sheet by counting pulses generated by the rotation detector means in response to the rocking of the arm and, adds a correction value to the measured sheet size according to the conveying speed of the sheet.
Claims35
A sheet size detecting apparatus comprising:
- a rotary member for conveying a sheet;
- rotation detecting means rotating together with said rotary member for generating pulses;
- arm means provided proximate to said rotary member to effect reciprocal rocking by passing of the front end and the rear end of the sheet;
- and
- control means for measuring an apparent size of the sheet by counting the pulses generated by said rotation detecting means in response to the rocking of said arm means, and adding a correcting rectified value to a measured apparent size according to a conveying speed of the sheet to get an actual size of the sheet.
A sheet size detecting apparatus comprising:
- a rotary member for conveying a sheet;
- a pulse generating means rotating together with and synchronous with said rotary member for generating pulses;
- an arm means provided proximate to said rotary member to effect a reciprocal rocking by passing of the front end and the rear end of the sheet;
- and
- control means for measuring an apparent size of the sheet by counting pulses generated by a pulse generating means in response to the rocking of said arm means, and adding a correcting rectification to a measured apparent size according to a conveying speed of the sheet to get an actual size of the sheet,
- wherein said control means includes a switching means to be turned on and off respectively by a forward motion and a reverse motion of said arm means, and a number of pulses is counted within a period from the turn-on to turn-off of said switch means.
An automatic original feeding apparatus having sheet size detecting apparatus comprising:
- a rotary member for conveying a sheet;
- rotation detecting means rotating together with said rotary member for generating pulses;
- arm means provided proximate to said rotary member to effect reciprocal rocking by passing of the front end and the rear end of the sheet;
- and
- control means for measuring an apparent size of the sheet by counting the pulses generated by said rotation detecting means in response to the rocking of said arm means, and adding a correcting rectification to a measured apparent size according to a conveying speed of the sheet to get an actual size of the sheet.
An automatic original feeding apparatus according to claim 38, wherein said rotary member stops, after conveying the sheet by a small amount, and then conveys the sheet again.
Dependencies are inferred from the claim text.