Apparatus and method for controlling print timing operations

A method of determining the position and velocity of a print medium, the medium having thereon a plurality of alphanumeric characters and a sequence of marks, including an index mark and a plurality of timing marks, uniformly disposed along a selected dimension of the medium, said timing marks being in relative alignment with the characters such that each character is associated with a pair of timing marks, said index mark designating a start location on the medium, the method comprising the steps of:

• positioning a detector proximate to the medium;
• detecting, upon movement of the medium along the selected dimension, the index mark and at least one pair of timing marks,
• producing a digital signal representative of the detected marks;
• and
• determining, according to the digital signal, the position on the medium of the character associated with the detected pair, and determining the velocity of the medium based on elapsed time between the detected timing marks.

An apparatus for determining position and velocity of a print medium, the apparatus comprising:

• detector means disposed proximate to the medium;
• said medium having thereon a plurality of alphanumeric characters and a sequence of marks, including an index mark and a plurality of timing marks, uniformly disposed along a selected dimension of the medium, said timing marks being in relative alignment with the characters such that each character is associated with a pair of timing marks, said index mark designating a start location on the medium;
• said detector means being responsive to movement of the medium along the selected dimension for detecting the index mark and at least one pair of timing marks, and producing a digital signal representative of the detected marks;
• and
• processor means coupled to said detector means and responsive to said digital signal for determining the position on the medium of the character associated with the detected pair, and determining the velocity of the medium based on elapsed time between the detected marks.

An apparatus for determining position and angular velocity of a print drum, the apparatus comprising:

• detector means disposed proximate to the drum;
• said drum having a cylindrical body with a plurality of alphanumeric characters and a sequence of marks, including an index mark and a plurality of timing marks, uniformly disposed about the circumference of the body, said timing marks being in relative alignment with the characters such that each character is associated with a pair of timing marks, said index mark designating a start location on the body;
• said detector means being responsive to rotation of the drum for detecting the index mark and at least one pair of timing marks, and producing a digital signal representative of the detected marks;
• and
• processor means coupled to said detector means and responsive to said digital signal for determining the position on the drum of the character associated with the detected pair, and determining the angular velocity of the drum based on elapsed time between detected marks.