Control system and method for handling sheet materials

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.

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.

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.