Control system and method for handling sheet materials

Claim 2

In an ink jet printer for producing imaged sheets of a predetermined length having an imaging drum, and a supply of sheet material within said drum, sheet material control means comprising first and second rollers carried by said drum, said sheet material extending around the exterior of said drum and thence between said first and second rollers, reversible drive means coupled to said rollers for operating in a forward direction to draw said sheet material from within said drum around the exterior thereof and thence away from said drum, and operating in a reverse direction to withdraw said sheet material toward said drum, cutter means spaced from said drum and arranged to receive and shear sheet material ejected from said drum, distance measuring means responsive to movement of said sheet material, means energizing said drive means to move said sheet material, and means under the control of said distance measuring means arranged to stop said drive means when said sheet material has moved a predetermined distance approximately equal to the said predetermined length of one of said imaged pages plus the distance between the surface of said drum and said cutter means.

Claim 3

Sheet material control means as claimed in claim 1 wherein said means energizing said drive means energizes said drive means in its forward direction to eject said sheet material toward said cutter means, said means energizing said drive means subsequently energizes said drive means in its reverse direction, and said means under the control of said distance measuring means stops said drive means when said sheet material has moved a predetermined distance approximately equal to the distance between the surface of said drum and said cutter means in the reverse direction.

Claim 4

In an ink jet printer having an imaging drum, and a supply of sheet material within said drum, sheet material control means comprising first and second rollers carried by said drum, said sheet material extending around the exterior of said drum and thence between said first and second rollers, reversible drive means coupled to said rollers for operating in a forward direction to draw said sheet material from within said drum around the exterior thereof and thence away from said drum, and operating in a reverse direction to withdraw said sheet material toward said drum, cutter means spaced from said drum and arranged to receive and shear sheet material ejected from said drum, measuring means responsive to movement of said sheet material including a third roller engaging and rotated by the surface of said sheet material, and including a counter for measuring the rotational movement of said third roller, means energizing said drive means to move said sheet material, and means under the control of said measuring means arranged to stop said drive means when said sheet material has moved a first predetermined distance.

Claim 5

In an ink jet printer having an imaging drum, and a supply of sheet material within said drum, sheet material control means comprising first and second rollers carried by said drum, said sheet material extending around the exterior of said drum and thence between said first and second rollers, reversible drive means coupled to said rollers for operating in a forward direction to draw said sheet material from within said drum around the exterior thereof and thence away from said drum, and operating in a reverse direction to withdraw said sheet material toward said drum, cutter means spaced from said drum and arranged to receive and shear sheet material ejected from said drum, measuring means responsive to movement of said sheet material including a third roller engaging and rotated by the surface of said sheet material, and including a counter for measuring the rotational movement of said third roller, means energizing said drive means to move said sheet material, and means under the control of said measuring means arranged to stop said drive means when said sheet material has moved a first predetermined distance.

Claim 6

Sheet material control means as claimed in claim 3 wherein said sheet material is maintained under pressure between said second and third rollers.

Claim 7

Sheet material control means as claimed in claim 4 wherein said sheet material extends from within said drum, thence between said first and second rollers, thence around the exterior of said drum, thence between said second and third rollers, and thence again between said first and second rollers.

Claim 8

Sheet material control means as claimed in claim 5 including alert indicator means responsive to the movement of said first roller and simultaneous non-movement of said third roller therby to indicate an operational problem.

Claim 9

Sheet material control means as claimed in claim 5 wherein said measuring means measures the net movement of said sheet material in a direction away from said drum, and including means for indicating when said net movement reaches a predetermined value.

Claim 10

In an ink jet printer of the type having an imaging drum, means for rotating said drum, a supply of sheet material within said drum, and a print head arranged to scan the surface of said drum, a sheet material transporting and measuring system comprising first, second and third rollers carried by said drum, means maintaining said first and third rollers biased toward said second roller, said sheet material extending from within said drum, between said first and second rollers, thence around the exterior of said drum, thence between said second and third rollers, and thence again between said second and third rollers, means for measuring the movement of said sheet material including means responsive to the rotational movement of said third roller, cutter means spaced from said drum and extending transversely across the path of said sheet material for separating the imaged portion of said sheet material, drive means coupled to said first and second rollers and operating in a forward direction to transport said sheet material from the interior of said drum, around the exterior thereof and thence toward said cutter means, and in a reverse direction to withdraw sheet material from said cutter means toward said drum, counter means coupled to said third roller for measuring the movement of said sheet material, and means under the control of said counter means for interrupting the operation of said drive means in its forward direction upon movement of a predetermined length of sheet material, and for interrupting the operation of said drive means in its reverse direction upon movement of a shorter predetermined length of said sheet material.

Claim 11

In an ink jet printer of the type having an imaging drum, means for rotating said drum, a supply of sheet material within said drum, and a print head arranged to scan the surface of said drum, a sheet material transporting and measuring system comprising first, second and third rollers carried by said drum, means maintaining said first and third rollers biased toward said second roller, said sheet material extending from within said drum, between said first and second rollers, thence around the exterior of said drum, thence between said second and third rollers, and thence again between said second and third rollers, means for measuring the movement of said sheet material including means responsive to the rotational movement of said third roller, cutter means spaced from said drum and extending transversely across the path of said sheet material for separating the imaged portion of said sheet material, drive means coupled to said first and second rollers and operating in a forward direction to transport said sheet material from the interior of said drum, around the exterior thereof and thence toward said cutter means, and in a reverse direction to withdraw sheet material from said cutter means toward said drum, counter means coupled to said third roller for measuring the movement of said sheet material, and means under the control of said counter means for interrupting the operation of said drive means in its forward direction upon movement of a predetermined length of sheet material, and for interrupting the operation of said drive means in its reverse direction upon movement of a shorter predetermined length of said sheet material.

Claim 12

Apparatus as claimed in claim 8 including alert indicating means responsive to the energization of said drive means in its forward direction and simultaneous non-movement of said third roller thereby to indicate a problem in the transport system.

Claim 13

In an ink jet printer for producing imaged sheets of a predetermined length of the type having an imaging drum and a supply of sheet material within said drum, and sheet cutter means spaced from said drum, the method comprising the steps of providing a sheet material drive, energizing said drive in a forward direction to eject said sheet material from said drum, measuring the movement of said sheet material, stopping said drive means when a first predetermined length of sheet material approximately equal to said predetermined length of one of said imaged sheets plus the distance between the surface of said drum and said sheet cutter means, shearing said sheet material along a line spaced from said drum, energizing said drive in a reverse direction to withdraw the sheared end of the sheet material toward said drum, measuring the movement of the sheet material toward said drum, and stopping said drive means when a second predetermined length of the sheet material approximately equal to the distance between the surface of said drum and said sheet cutter means has been withdrawn.

Claim 14

In an ink jet printer for producing imaged sheets of a predetermined length of the type having an imaging drum and a supply of sheet material within said drum, and sheet cutter means spaced from said drum, the method comprising the steps of providing a sheet material drive, energizing said drive in a forward direction to eject said sheet material from said drum, measuring the movement of said sheet material, stopping said drive means when a first predetermined length of sheet material approximately equal to said predetermined length of one of said imaged sheets plus the distance between the surface of said drum and said sheet cutter means, shearing said sheet material along a line spaced from said drum, energizing said drive in a reverse direction to withdraw the sheared end of the sheet material toward said drum, measuring the movement of the sheet material toward said drum, and stopping said drive means when a second predetermined length of the sheet material approximately equal to the distance between the surface of said drum and said sheet cutter means has been withdrawn.

Claim 15

The method as claimed in claim 10 including the additional steps of sensing the energization of said drive, simultaneously sensing the movement of said sheet material, and providing an indication of a malfunction when said drive is energized and said sheet material is stationary.