Contact control of print blanket to impression drum

1. A method of controlling contact between a print blanket and an impression drum, comprising:

printing a print job in a printing device that comprises a print blanket to receive an ink image from a photoreceptor in a first transfer, and to transfer the ink image onto print media supported on an impression drum in a second transfer;

during the printing, positioning the impression drum in a print position to create a print width nip level contact between the print blanket and the impression drum, and receiving a null cycle trigger; and,

in response to the trigger, repositioning the impression drum to a null position to reduce contact between the print blanket and the impression drum from the print width nip level contact to a null width level contact.

2. A method as in claim 1 , wherein to reduce contact between the print blanket and the impression drum comprises reducing compression of the print blanket in a contact area between the print blanket and the impression drum.

3. A method as in claim 2 , wherein the contact area between the print blanket and the impression drum comprises a nip, and reducing compression of the print blanket comprises reducing a width of the nip.

4. A method as in claim 1 , wherein the print blanket is wrapped around an intermediate transfer medium (ITM) drum, and to reduce contact between the print blanket and the impression drum comprises:

displacing the impression drum away from the ITM drum while leaving the ITM drum stationary.

5. A method as in claim 1 , further comprising, suspending writing and development of images to the photoreceptor and halting transportation of print media to the impression drum during the null cycle.

6. A method as in claim 1 , wherein receiving a null cycle trigger comprises receiving an interrupt signal from a printing subsystem indicating the subsystem is not ready to continue the printing.

7. A method as in claim 5 , further comprising:

during the null cycle, receiving an additional null cycle trigger; and

in response to the additional null cycle trigger, maintaining the null width level contact between the print blanket and the impression drum; and

continuing to suspend writing and development of images to the photoreceptor and halt transportation of print media to the impression drum.

8. A printing device comprising:

a photoreceptor on an imaging cylinder, the photoreceptor for developing an ink image to a latent image;

a print blanket to transfer the ink image from the photoreceptor onto print media on an impression (IMP) drum during printing;

a drum displacer to displace the IMP drum; and

a controller to receive a null cycle trigger, and in response to the trigger, to cause the drum displacer to move the IMP drum out of a print position in which there is a print width nip level contact between the print blanket and the impression drum, and into a null position in which there is a null width level contact between the print blanket and the impression drum.

9. A printing device as in claim 8 , further comprising a printing subsystem selected from a media transport subsystem and a color calibration subsystem, the subsystem to generate the null cycle trigger when the subsystem senses it is not ready to perform a print cycle.

10. A non-transitory machine-readable storage medium storing instructions that when executed by a processor of a printing device, cause the printing device to:

during a print cycle of a printing process, in which a print blanket is to receive an ink image from a photoreceptor in a first transfer, and to transfer the ink image onto print media supported on an impression drum in a second transfer, detect an interrupt from a printing subsystem;

in response to detecting the interrupt,

reduce contact between a print blanket and an impression drum from a print level to a null level; and

insert a first null cycle into the printing process following the print cycle;

insert an additional null cycle following the first null cycle for each null cycle in which the detection of the interrupt persists; and

maintain the reduced contact between the print blanket and the impression drum during each null cycle.

11. A non-transitory machine-readable storage medium as in claim 10 , the instructions further causing the printing device to:

detect that the interrupt has stopped;

in response to detecting that the interrupt has stopped, increase the contact level between the print blanket and the impression drum from the null level back to the print level; and,

insert a print cycle into the printing process following the null cycle.

12. A non-transitory machine-readable storage medium as in claim 11 , wherein detecting that the interrupt has stopped occurs during a last null cycle in a series of null cycles that begins with the first null cycle.

13. A non-transitory machine-readable storage medium as in claim 12 , wherein the last null cycle comprises the first null cycle.

14. A non-transitory machine-readable storage medium as in claim 10 , wherein the impression drum comprises a first axis and the print blanket is wrapped around an ITM drum having a second axis, and wherein reducing the contact between the print blanket and the impression drum comprises:

increasing a distance between the first axis and the second axis.