Temperature monitoring system

1. A temperature monitoring system for generating a representation of the temperature of the regions of a heated sheet of a rotary thermoforming machine, the system comprising:

a temperature detector for detecting the respective temperatures of areas of the sheet extending in a line across the sheet;

a device for monitoring relative rotary movement between the sheet and the temperature detector; and

a processing system for

a) recording the coordinates and the detected temperature of each area whose temperature is monitored; and

b) determining the temperature of regions of the sheet defined on a different basis to the areas by applying a predetermined algorithm to the data stored in step a) which takes account of the relative rotary movement of the sheet.

2. A system according to claim 1 , wherein the processing system defines the coordinates of each area in step a) by means of a polar coordinate system centered on the axis of rotation of the sheet.

3. A system according to claim 2 , wherein each region whose temperature is determined in step b) has substantially the same size.

4. A rotary thermoforming machine including a temperature monitoring system according to claim 2 .

5. A system according to claim 1 , wherein each region whose temperature is determined in step b) has substantially the same size.

6. A rotary thermoforming machine including a temperature monitoring system according to claim 5 .

7. A system according to claim 1 , wherein the regions for which temperatures are determined in step b) are defined in a Cartesian array.

8. A system according to claim 1 , wherein the processing system is adapted to define the regions at substantially the same resolution as the areas.

9. A system according to claim 1 , wherein the predetermined algorithm compensates for acceleration and deceleration movements of the sheet.

10. A system according to claim 1 , wherein the temperature detector detects the temperature of successive lines of said areas, the processing system being adapted to carry out steps a) and b) during the detection process.

11. A system according to claim 10 , wherein the processing system causes the temperatures of the regions to be displayed during the scanning process.

12. A system according to claim 11 , wherein the linescanner incorporates a laser.

13. A system according to claim 1 , further comprising a display for displaying the temperature of the regions as determined in step b) in the form of a map.

14. A system according to claim 13 , wherein the processing system causes the temperatures of the regions to be displayed during the scanning process.

15. A system according to claim 1 , wherein the temperature detector comprises a linescanner with an opto-mechanical scanning mechanism.

16. A system according to claim 1 , further comprising a rotation detector for monitoring rotary movement of the sheet, the processing system being responsive to the rotary detector to determine the coordinates in step a).

17. A rotary thermoforming machine including a temperature monitoring system according to claim 1 .

18. A temperature monitoring system for generating a representation of the temperature of regions of a heated sheet in a rotary thermoforming machine, the system comprising:

a temperature detecting linescanner for detecting the respective temperatures of areas of the sheet extending in a line across the sheet relative to a direction of rotary movement of the sheet;

a device for monitoring relative rotary movement between the sheet and the temperature detecting linescanner; and

a processing system for

recording, for each area whose temperature is detected by the temperature detecting linescanner, the detected temperature and the coordinates of that area;

transforming the coordinates, so recorded, to Cartesian coordinates referenced to the plane of the sheet by accounting for the relative rotary movement of the sheet; and

determining the temperature of regions of the sheet defined by the Cartesian coordinates based on the transformed coordinates and the recorded temperatures.

19. A method of generating a representation of the temperature of the regions of a heated sheet, the method comprising:

rotating a rotary thermoforming machine's carousel on which the heated sheet is disposed so that the sheet passes by a temperature detector;

detecting, with the temperature detector, the respective temperatures of areas of the sheet extending in a line across the sheet as the sheet moves past the temperature detector;

monitoring relative rotary movement between the sheet and the temperature detector;

recording the coordinates and temperature of each area whose the detected temperature is monitored; and

determining the temperature of regions of the sheet defined on a different basis to the areas by applying a predetermined algorithm to the data, so recorded, which takes account of the relative rotary movement of the sheet; and

outputting the temperatures of the regions, so determined.

20. A method according to claim 19 , wherein the predetermined algorithm transforms recorded coordinates of the areas to Cartesian coordinates.

21. A method according to claim 19 , wherein outputting the temperatures of the regions comprises outputting the temperatures of the regions for display.

22. A method according to claim 19 , wherein outputting the temperatures of the regions comprises outputting the temperatures of the regions to a storage device for storage.