Production line control using shift registers for contact lens manufacture
View Patent ↗A method for controlling a production line for the manufacture and/or packaging of contact lenses which production line simultaneous by processes at least two lots, the method comprising dividing at least a portion of the production line into a series of cells through which the contact lens pass sequentially, and providing a control system comprising at least three shifts registers each containing information about each of said cells, including: (a) a location shift register which indicates whether a cell should be empty or occupied, (b) a lot data shift register which is a non-binary shift register and contains manufacturing and/or prescription data about the contact lens which should be in the cell and (c) a condition shift register which provides an indication of the condition of the product in the cell, and simultaneously indexing all of said shift registers as a lens passes down the production line from one cell to the next cell.
1. A method for controlling a production line that can simultaneously manufacture and/or package at least two lots of contact lenses, the method comprising;
dividing at least a portion of the production line into a series of cells through which the contact lenses pass sequentially,
providing a control system comprising at least three shift registers each containing information about each of said cells, including:
(a) a location shift register which indicates whether a cell should be empty or occupied,
(b) a lot data shift register which is a non-binary shift register and contains manufacturing and/or prescription data about the contact lens which should be in the cell and
(c) a condition shift register which provides an indication of the condition of the lens in the cell, and
simultaneously indexing all of said shift registers as a lens passes down the production line from one cell to the next cell.
2. A method as claimed in claim 1 further comprising detecting the presence or absence of product in a cell and comparing the result with the information for that cell in the location shift register.
3. A method as claimed in claim 2 further comprising inserting a plurality of adjacent empty cells at the start and end of a manufacturing lot.
4. A method as claimed in claim 3 wherein the detecting of said plurality of empty cells is used to trigger a processing event.
5. A method as claimed in claim 4 wherein the processing event is selected from resetting a processing station, wiping data from a processing station and instigating a reporting action.
6. A method as claimed in claim 1 further comprising inserting a gap comprising a predetermined number of empty cells positioned between-successive manufacturing lots on the production line and the control system further comprises a gap defence mechanism including detectors and counters to monitor said gap as it proceeds down the production line.
7. A method as claimed in claim 1 wherein the manufacturing and/or prescription data from the lot data shift register is used to control the activity of a cell.
8. A method as claimed in claim 1 further comprising the step of inspecting the product in a cell and/or monitoring the production activity in a cell and comparing the resulting data with data in the lot data shift register.
9. A method as claimed in claim 1 wherein information regarding the condition of the product in the condition shift register is used to trigger ejection of a product from the production line.
10. A method as claimed in claim 9 wherein the ejection of product from the production line causes the location shift register to change to signify the cell is empty of product.
11. A method as claimed in claim 4 further comprising inserting a gap comprising a predetermined number of empty cells positioned between-successive manufacturing lots on the production line and the control system further comprises a gap defence mechanism including detectors and counters to monitor said gap as it proceeds down the production line.
12. A method as claimed in claim 4 further comprising inspecting the product in a cell and/or monitoring the production activity in a cell and comparing the resulting data with data in the lot data shift register.
13. A production line for the simultaneous manufacture and/or packaging of at least two lots of contact lenses, the production line comprising:
a series of cells through which the contact lenses pass sequentially;
a control system comprising at least three shift registers each of which contain information about each of the cells, including:
(a) a location shift register which indicates whether a cell should be empty or occupied,
(b) a lot data shift register which is a non-binary shift register and contains manufacturing and/or prescription data about the contact lens which should be in the cell, and
(c) a condition shift register which provides an indication of the condition of the lens in the cell, and
a means for simultaneously indexing all of said shift registers as a lens passes down the production line from one cell to the next cell.
14. A production line as claimed in claim 13 further comprising a means for detecting the presence or absence of product in a cell and comparing the result with the information for that cell in the location shift register.
15. A production line as claimed in claim 13 further comprising a means for ejecting a product from the production line based upon information on the condition of the product in the condition shift register.