Dynamic drying of print media in a radiant dryer

1. An apparatus comprising:

a radiant dryer operable to receive a continuous-form print medium marked with a wet colorant that depicts a sheetside of print data and a test patch, the radiant dryer including:

a radiant energy source within an interior of the dryer that is operable to heat the colorant based on a heating power to affix the colorant to the medium; and

a cooling system within the interior of the dryer that is operable to apply a cooling gas to the medium; and

a control system operable to obtain a temperature of the test patch, to determine a difference between the temperature of the test patch and a target temperature, and to vary at least one parameter selected from the heating power and an application of the cooling gas based on the difference to normalize temperatures across the medium during a drying process.

2. The apparatus of claim 1 wherein:

the wet colorant depicts a plurality of test patches; and

the control system is further operable to obtain temperatures of the plurality of test patches, to identify a first test patch having a temperature below the target temperature, and to increase the heating power to normalize the temperatures across the medium during the drying process.

3. The apparatus of claim 2 wherein:

the control system is further operable to identify a second test patch having a temperature above the target temperature, and to increase the application of the cooling gas to normalize the temperatures across the medium during the drying process.

4. The apparatus of claim 2 wherein:

the test patches are marked with a plurality of colorants that vary in radiant energy absorption characteristics.

5. The apparatus of claim 2 wherein:

the test patches are marked with the colorant at different densities.

6. The apparatus of claim 1 wherein:

the target temperature varies by a threshold amount.

7. A method comprising:

receiving a continuous-form medium marked with a wet colorant that depicts a sheetside of print data and a test patch.

heating the colorant based on a heating power to affix the colorant to the medium;

applying a cooling gas to the medium;

obtaining a temperature of the test patch;

determining a difference between the temperature of the test patch and a target temperature; and

varying at least one parameter selected from the heating power and an application of the cooling gas based on the difference to normalize temperatures across the medium during a drying process.

8. The method of claim 7 wherein:

the wet colorant depicts a plurality of test patches;

obtaining the temperature further comprises:

obtaining temperatures of the plurality of test patches; and

varying at least one parameter further comprises:

identifying a first test patch having a temperature below the target temperature; and

increasing the heating power to normalize the temperatures across the medium during the drying process.

9. The method of claim 8 wherein:

varying at least one parameter further comprises:

identifying a second test patch having a temperature above the target temperature; and

increasing the application of the cooling gas to normalize the temperatures across the medium during the drying process.

10. The method of claim 8 wherein:

the test patches are marked with a plurality of colorants that vary in radiant energy absorption characteristics.

11. The method of claim 8 wherein:

the test patches are marked with the colorant at different densities.

12. The method of claim 7 wherein:

the target temperature varies by a threshold amount.

13. A non-transitory computer readable medium embodying programmed instructions executable by a processor, the instructions operable to direct the processor to:

receive a continuous-form medium marked with a wet colorant that depicts a sheetside of print data and a test patch.

heat the colorant based on a heating power to affix the colorant to the medium;

apply a cooling gas to the medium;

obtain a temperature of the test patch;

determine a difference between the temperature of the test patch and a target temperature; and

vary at least one parameter selected from the heating power and an application of the cooling gas based on the difference to normalize temperatures across the medium during a drying process.

14. The medium of claim 13 wherein:

the wet colorant depicts a plurality of test patches;

instructions to obtain the temperature further comprise instructions to:

obtain temperatures of the plurality of test patches; and

instructions to vary at least one parameter further comprise instructions to:

identify a first test patch having a temperature below the target temperature; and

increase the heating power to normalize the temperatures across the medium during the drying process.

15. The medium of claim 14 wherein:

instructions to vary at least one parameter further comprise instructions to:

identify a second test patch having a temperature above the target temperature; and

increase the application of the cooling gas to normalize the temperatures across the medium during the drying process.

16. The medium of claim 14 wherein:

the test patches are marked with a plurality of colorants that vary in radiant energy absorption characteristics.

17. The medium of claim 14 wherein:

the test patches are marked with the colorant at different densities.

18. The medium of claim 14 wherein:

the target temperature varies by a threshold amount.