Web transport device
AssigneeCanon Kabushiki Kaisha
InventorsKazuo Kashiwagi, Masanari Shirai
Life of this patent
Estimating the term…
Abstract
A web transport device for transporting a web wound on a rotary member to another rotary member, provided with a first calculating unit for calculating the ratio of rotating speeds of the unwinding and winding rotary members at a regular interval, a second calculating unit for calculating the ratio of rotating speeds of the unwinding and winding rotary members at the end of web transport on the basis of the value calculated by the first calculating unit at the start of web transport, and a unit for controlling the rotation of the rotary members through the comparison of the values calculated by the first and second calculating units, respectively.
Claims6
A web transport device for transporting a web wound on an unwinding rotary member to a winding rotary member by the rotation thereof, comprising:
- measuring means for measuring the rotating speed of the unwinding rotary member and of the winding rotary member;
- first computing means for calculating the ratio of the rotating speed of the unwinding rotary member and of the winding rotary member within a predetermined period in the course of web transport;
- second computing means for calculating the ratio of the rotating speeds of the unwinding rotary member and of the winding rotary member at the end of web transport on the basis of a value calculated by said first computing means at the start of web transport;
- and
- transport control means for comparing the results of calculations of said first and second computing means and controlling the drive for said rotary members in response to the result of said comparison.
A web transport device for transporting a web wound on an unwinding rotary member to a winding rotary member by the rotation thereof, comprising:
- first pulse generating means for generating a pulse at rotation, by a predetermined angle, of the unwinding rotary member;
- second pulse generating means for generating a pulse at rotation, by a predetermined angle, of the winding rotary member;
- first counting means connected with said first pulse generating means and adapted to count the pulses generated by the first pulse generating means;
- second counting means connected with said second pulse generating means and adapted to count the pulses generated by the second pulse generating means;
- first computing means for calculating the ratio of the numbers of pulses counted by said first and second counting means during a predetermined period;
- second computing means for predicting, from the value calculated by said first computing means at the start of web transport, a value to be calculated by said first computing means at the end of web transport;
- and
- control means for comparing the values calculated by said first and second computing means and controlling the drive for said rotary members when said values mutually coincide.
Dependencies are inferred from the claim text.