Gate control for printed web scanner

Apparatus for splicing web material feeding to web handling mechanism and having register marks located in clear portions of a track running through clear and unclear portions of repeat patterns thereon, said apparatus including a splicing head operable during a splicing cycle to join an expiring web at said splicing head with the leading edge of a new web located at said splicing head comprising:

• a. a scanner positioned adjacent said expiring web a fixed distance from said splicing head for emitting a scanning pulse upon detection of a register mark in the track of said expiring web;
• b. an encoder driven in synchronism with the feed of said expiring web for emitting pulses representing increments of web feed length;
• and
• c. a reset digital counter connected to said encoder and said scanner and responsive to receipt of a predetermined number of pulses from said encoder for gating the operation of said scanner to inhibit scanning of unclear track portions while counting up to said predetermined number and to enable scanning of clear track portions upon reaching said predetermined number, said counter being reset by receipt of a scanning pulse to deactivate said scanner and conditionable to initiate a splicing cycle when reset by receipt of a scanning pulse.

Apparatus for splicing web material feeding to web handling mechanism and having register marks located in clear portions of a track running through clear and unclear portions of repeat patterns thereon, said apparatus including a splicing head operable during a splicing cycle to join an expiring web at said splicing head with the leading edge of a new web located at said splicing head comprising:

• a. a scanner positioned adjacent said expiring web a fixed distance from said splicing head for emitting a scanning pulse upon detection of a register mark in the track of said expiring web;
• b. an encoder driven in synchronism with the feed of said expiring web for emitting pulses representing increments of web feed length;
• c. a reset digital counter connected to said encoder and said scanner and responsive to receipt of a predetermined number of pulses from said encoder for gating the operation of said scanner, said predetermined number being a number less than the number of pulses representing the distance between successive register marks to inhibit the scanning of unclear track portions while counting up to said predetermined number and to enable scanning of clear track portons upon reaching said predetermined number, said counter being reset by receipt of a scanning pulse to deactivate said scanner and conditionable to initiate a splicing cycle when reset by receipt of a scanning pulse;
• and
• d. a second digital counter activated at the start of a splicing cycle to measure the expiring web feeding to said splicing head and effective to activate said splicing head after the feed of a measured length of expiring web calculated to bring the reset patterns on the respective webs in register with one another.

A method for detecting register marks in clear portions of a track running through clear and unclear portions of repeat patterns on a moving web comprising the steps of:

• a. directing said web past a scanner aligned with said track and adapted to emit a scanning pulse upon detecting a register mark therein;
• b. generating pulses synchronized with web movement whereby each pulse represents an increment of web feed length;
• c. using a reset digital counter for counting said pulses up to a predetermined number which is less than the number of pulses representing the distance between successive register marks and greater than the number of pulses representing the distance from a register mark to the clear track portion containing the next register mark;
• d. inhibiting said scanner during said counting;
• e. enabling said scanner to scan clear portions after completing said counting;
• and
• f. resetting said counter and deactivating said scanner upon receipt of a scanning pulse.

A method for controlling apparatus adapted to splice feeding web material having register marks located in clear portions of a track running through clear and unclear portions of repeat patterns thereon, said apparatus including a splicing head operable during a splicing cycle to join an expiring web at said splicing head with the leading edge of a new web located at said splicing head comprising the steps of:

• a. directing said expiring web past a scanner aligned with said track and adapted to emit a scanning pulse upon detecting a register mark therein;
• b. generating pulses synchronized with web movement whereby each pulse represents an increment of web feed length;
• c. using a reset digital counter for counting said pulses up to a predetermined number which is less than the number of pulses representing the distance between successive register marks and greater than the number of pulses representing the distance from a register mark to the clear track portion containing the next register mark;
• d. inhibiting said scanner during said counting;
• e. enabling said scanner to scan clear portions upon completion of said counting;
• f. resetting said counter to deactivate said scanner and repeat said counting upon detection of a register mark by said scanner;
• and
• g. initiating a splicing cycle at the moment a selected register mark is detected by said scanner.

A method for controlling apparatus adapted to splice feeding web material having register marks located in clear portions of a track running through clear and unclear portions of repeat patterns thereon, said apparatus including a splicing head operable during a splicing cycle to join an expiring web at said splicing head with the leading edge of a new web at said splicing head comprising the steps of:

• a. directing said expiring web past a scanner aligned with said track and adapted to emit a scanning pulse upon detecting a register mark therein;
• b. generating pulses synchronized with web feed whereby each pulse represents an increment of web feed length;
• c. using a reset digital counter for counting said pulses up to a predetermined number which is less than the number of pulses representing the distance between successive register marks and greater than the number of pulses representing the distance from a register mark to the clear track portion containing the next register mark;
• d. inhibiting said scanner during said counting;
• e. enabling said scanner to scan clear portions after completing said counting;
• f. resetting said counter to deactivate said scanner and repeat said counting upon detection of a register mark by said scanner;
• g. measuring the feed of the expiring web to the splicing head from the moment a selected register mark is detected by said scanner;
• and
• h. activating said splicing head after feed of a measured length of said expiring web calculated to bring a pattern on the expiring web in register with a pattern of the new web at the splicing head.