Feedforward control of downstream register errors for electronic roll-to-roll printing system
AssigneeKonkuk University Industrial Cooperation Corp.
InventorsKee-Hyun Shin, Hyun-Kyoo Kang
Life of this patent
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Abstract
An ultra-precision register control method in a continuous roll-to-roll printing process for manufacturing electronic devices via a feedforward register control logic, which compensates for and eliminates additional register errors attributable to variations in the speed of upstream printing cylinders. When used in combination with a conventional feedback register control logic, the feedforward register control logic accomplishes a register control with ultra-precision in a continuous roll-to-roll printing process, and enables implementation of a continuous roll-to-roll printing process for manufacturing electronic devices, for which a roll-to-roll printing process was formerly unavailable.
Claims7
A method of controlling register errors with ultra-precision in a system of a continuous roll-to-roll printing process for manufacturing electronic devices, the system having N printing cylinders having numerical orders of 1, 2, . . . , i, . . . N, respectively, where N is an integer equal to or greater than 3, and a material continuously fed to the printing cylinders for printing the electronic devices thereon, the method comprising the steps of:
- (a) measuring a first register error for the material, after the material having passed through a second printing cylinder;
- (b) calculating a first feedback speed variation of the second printing cylinder to compensate for the first register error;
- (c) changing the speed of the second printing cylinder by the first feedback speed variation of the second printing cylinder;
- (d) measuring a second register error for the material, after the material having passed through a third printing cylinder;
- (e) calculating a second feedback speed variation of the third printing cylinder to compensate for the second register error;
- (f) calculating a first feedforward speed variation of the third printing cylinder by using as an input the first feedback speed variation of the second printing cylinder;
- and
- (g) changing the speed of the third printing cylinder by a net speed variation of the third printing cylinder equal to the addition of the second feedback speed variation of the third printing cylinder and the first feedforward speed variation of the third printing cylinder,
- wherein in step (f) the first feedforward speed variation of the third printing cylinder, V3, is represented by the following equation,
- V
- 3
-
- (
- s
- )
- =
- [
- 1
- -
- 1
- τ
-
-
- s
- +
- 1
- +
- ⅇ
- -
- τ
-
-
- s
- ]
-
- V
- 2
-
- (
- s
- )
- L
- -
- 1
-
- [
- V
- 3
-
- (
- s
- )
- ]
- =
- L
- -
- 1
-
- [
- V
- 2
-
- (
- s
- )
- -
- 1
- τ
-
-
- s
- +
- 1
-
- V
- 2
-
- (
- s
- )
- +
- V
- 2
-
- (
- s
- )
-
- ⅇ
- -
- τ
-
-
- s
- ]
- =
- L
- -
- 1
-
- [
- V
- 2
-
- (
- s
- )
- ]
- -
- L
- -
- 1
- [
- 1
- τ
-
- 1
- (
- s
- +
- 1
- τ
- )
-
- V
- 2
-
- (
- s
- )
- ]
- +
- L
- -
- 1
-
- [
- V
- 2
-
- (
- s
- )
-
- ⅇ
- -
- τ
-
-
- s
- ]
- =
- υ
- 2
-
- (
- t
- )
- -
- 1
- τ
-
- ⅇ
- (
- -
- 1
- τ
- )
-
- t
-
- υ
- 2
-
- (
- t
- )
- +
- υ
- 2
-
- (
- t
- -
- τ
- )
- where V2 is the first feedback speed variation of the second printing cylinder, τ is a time constant, and s is a Laplace domain variable (complex variable), and
- wherein τ is calculated by an equation of L/V, L designating a length of a span between adjacent cylinders and V and ν designating an operating speed of the system of a continuous roll-to-roll printing process in Laplace domain and in time domain, respectively.
Dependencies are inferred from the claim text.