SYSTEM AND METHOD FOR PRINTING PACKAGES
A printing system includes a conveyor, at least one ink jet head, and an actuator operable to move the at least one ink jet head relative to the conveyor. A first sensor and a second sensor are adapted to sense a particular dimension and an entire area of a surface of a package, respectively. A control system is responsive to the first sensor and the second sensor and is operable to position the at least one ink jet head for printing. A method of printing is also disclosed.
1 . A printing system, comprising:
a conveyor;
at least one ink jet head;
an actuator operable to move the at least one ink jet head relative to the conveyor;
a first sensor and a second sensor adapted to sense a particular dimension and an entire area of a surface of a package, respectively; and
a control system responsive to the first sensor and the second sensor and operable to position the at least one ink jet head for printing.
2 . The printing system of claim 1 , wherein the first sensor senses package height at a first resolution.
3 . The printing system of claim 2 , wherein the second sensor senses package height at a second resolution finer than the first resolution.
4 . The printing system of claim 1 , wherein the first sensor comprises at least one emitter/detector to sense at least one distance.
5 . The printing system of claim 1 , wherein the first sensor comprises a plurality of emitters/detectors to sense multiple distances.
6 . The printing system of claim 1 , wherein the first sensor is operable at intervals to sense multiple distances.
7 . The printing system of claim 1 , wherein the second sensor comprises a micrometer to sense a plurality of distances.
8 . The printing system of claim 7 , wherein the first sensor is operable to sense a first plurality of heights at a first resolution and the micrometer is operable to sense a second plurality of heights at a second resolution finer than the first resolution.
9 . The printing system of claim 8 , wherein the control system is operable to move a print apparatus to a position within a range of gap distances from the package.
10 . The printing system of claim 1 , wherein the at least one ink jet head is a piezoelectric printhead.
11 . The printing system of claim 1 , wherein the at least one ink jet head is a drop on demand ink jet printhead.
12 . The printing system of claim 1 , wherein the at least one ink jet head is disposed in a print head housing wherein the actuator moves the print head housing to move the at least one ink jet head.
13 . The printing system of claim 12 , wherein the print head housing comprises at least four ink jet heads disposed therein.
14 . A method of printing on packages, the method comprising the steps of:
operating a first sensor to measure a dimension of a package to obtain an approximate dimension measurement;
establishing a position of a second sensor in dependence upon the approximate dimension measurement;
operating the second sensor to measure the dimension of the package to obtain a further dimension measurement;
disposing a print apparatus at a position dependent upon the further dimension measurement; and
operating the print apparatus to print on a surface of the package.
15 . The method of claim 14 , wherein the step of operating the first sensor comprises the step of operating at least one emitter/detector to sense at least one distance.
16 . The method of claim 14 , wherein the step of operating the first sensor comprises the step of operating a plurality of emitters/detectors to sense multiple distances.
17 . The method of claim 14 , wherein the step of operating the second sensor comprises the step of operating a micrometer to sense a plurality of distances.
18 . The method of claim 14 , wherein the step of operating the second sensor comprises the step of operating a light sensor to sense a plurality of distances.
19 . The method of claim 14 , wherein each of the steps of operating the first and second sensors comprises the step of sensing a height of the package.
20 . The method of claim 19 , wherein the step of disposing the print apparatus comprises the step of moving the print apparatus to a position within a range of gap distances from the package.