Devices, systems, and methods for supplying makeup air through openings in carrier plates of printing system via an air guide structure
A printing system comprises a print fluid deposition assembly, a media transport device, and an air flow control system. The print fluid deposition assembly comprises a printhead to eject a print fluid through an opening of a carrier plate to a deposition region. The media transport device holds a print medium against the movable support surface by vacuum suction and transports the print medium through the deposition region. The air flow control system comprises an air supply unit to selectively flow air through the opening based on a location of a print medium relative to the printhead. The air supply unit comprises an air guide structure comprising an air outlet portion extending into the opening of the carrier plate between the printhead and the carrier plate, the air outlet portion terminating in an end wall that is angled obliquely relative to the movable support surface towards a reverse-process direction.
1. A printing system, comprising:
a print fluid deposition assembly comprising:
a carrier plate comprising an opening;
a printhead supported by the carrier plate, wherein the printhead is arranged to eject a print fluid through the opening of the carrier plate and to a deposition region of the print fluid deposition assembly; and
a media transport device comprising a movable support surface, the media transport device configured to hold a print medium against the movable support surface by vacuum suction and the movable support surface configured to transport the print medium along a process direction through the deposition region of the print fluid deposition assembly; and
an airflow control system comprising an air supply unit arranged to flow air through the opening of the carrier plate between the carrier plate and the printhead,
wherein the airflow control system is configured to control the air supply unit to selectively flow the air based on a location of a print medium transported by the media transport device relative to the printhead, and
wherein the air supply unit comprises an air guide structure comprising an air outlet portion extending into the opening of the carrier plate between the printhead and the carrier plate, the air outlet portion terminating in an end wall that has a face angled obliquely relative to the movable support surface towards a reverse-process direction, the end wall defining one or more outlet openings in the face through which the air exits the air supply unit.
2. The printing system of claim 1 , wherein the air guide structure further comprises:
an air inlet portion narrower than the air outlet portion in a cross-process direction, and
a transitional portion between the air inlet portion to the air outlet portion, a width of the transitional portion increasing from the air inlet portion to the air outlet portion.
3. The printing system of claim 1 , wherein:
the media transport device is configured to hold a plurality of print media, including the print medium, by vacuum suction against the movable support surface such that consecutive print media are spaced from each other via an inter-media zone, and
the airflow control system is configured to selectively flow the air based on a location of the inter-media zone relative to the printhead.
4. The printing system of claim 1 , wherein the air supply unit is one of a plurality of air supply units, the plurality of air supply units comprising:
an upstream air supply unit arranged to flow air at an upstream side of the printhead and a downstream air supply unit arranged to flow air at a downstream side of the printhead,
wherein the airflow control system is configured to individually control the upstream air supply unit and the downstream air supply unit to selectively flow air, and
wherein upstream and downstream are defined relative to the process direction.
5. The printing system of claim 4 , wherein:
the media transport device is configured to hold a plurality of print media, including the print medium, against the movable support surface such that consecutive print media are spaced apart from each other via an inter-media zone,
the airflow control system is configured to control the upstream air supply unit to supply the air when the inter-media zone reaches a first position relative to the printhead, and to cease supplying air when the inter-media zone reaches a second position relative to the printhead, and
the airflow control system is configured to control the downstream air supply unit to supply the air when an inter-media zone reaches a third position relative to the printhead, and to cease supplying the air when the inter-media zone reaches a fourth position relative to the printhead.
6. The printing system of claim 5 , wherein the first position is upstream of the second and third positions, and the second and third positions are upstream of the fourth position.
7. The printing system of claim 6 , wherein the second position is the same as the third position.
8. The printing system of claim 5 , wherein:
the print medium is a first print medium and wherein a second print medium of the plurality of print media consecutively follows and is upstream of the first print medium, and wherein lead and trail edges of the print media are defined based on the process direction through the deposition region,
the first position corresponds to a trail edge of the first print medium being near the upstream side of the printhead,
the second position corresponds to the lead edge of a second print medium being near the upstream side of the printhead,
the third position corresponds to the trail edge of the first print medium being near a downstream side of the printhead, and
the fourth position corresponds to the lead edge of the second print medium being near the downstream side of the printhead.
9. The printing system of claim 1 , wherein:
the air supply unit comprises an air source configured to selectively supply the air to an air inlet portion of the air guide structure.
10. The printing system of claim 9 , wherein:
the air supply unit further comprises a controllable valve configured to selectively control a supply of air from the air source to the air outlet portion of the air guide structure.
11. The printing system of claim 9 , wherein the air source comprises a fan.
12. The printing system of claim 1 , wherein the movable support surface comprises a belt with holes through the belt.
13. The printing system of claim 1 , further comprising:
a control system configured to automatically control the airflow control system to selectively flow the air based on a monitored amount of image blur in printed images.
14. The printing system of claim 1 , wherein the air guide structure is attached to the printhead.
15. The printing system of claim 14 , wherein the air guide structure is removably attached to the printhead.
16. A printing system comprising:
a print fluid deposition assembly comprising:
a carrier plate comprising an opening;
a printhead supported by the carrier plate, wherein the printhead is arranged to eject a print fluid through the opening of the carrier plate and to a deposition region of the print fluid deposition assembly; and
a media transport device comprising a movable support surface, the media transport device configured to hold a print medium against the movable support surface by vacuum suction and the movable support surface configured to transport the print medium along a process direction through the deposition region of the print fluid deposition assembly; and
an airflow control system comprising an air supply unit arranged to flow air through the opening of the carrier plate between the carrier plate and the printhead,
wherein the airflow control system is configured to control the air supply unit to selectively flow the air based on a location of a print medium transported by the media transport device relative to the printhead, and
the air supply unit comprises an air guide structure removably attached to the printhead.
17. A method of operating a printing system, the method comprising:
transporting a print medium through a deposition region of a print fluid deposition assembly of the printing system, wherein the print medium is held against a moving movable support surface via vacuum suction during the transporting;
ejecting print fluid from a printhead of the print fluid deposition assembly through an opening in a carrier plate supporting the printhead to deposit the print fluid to the print medium in the deposition region; and
controlling an airflow control system to selectively flow air through the opening in the carrier plate between the carrier plate and the printhead and to the movable support surface,
wherein the controlling is based on a location of the print medium relative to the printhead, and
wherein the selectively flowing the air comprises flowing the air through an air guide structure comprising an air outlet portion extending into the opening of the carrier plate between the printhead and the carrier plate and terminating in an end wall that has a face angled obliquely relative to the movable support surface toward a direction opposite a direction of the transporting, and flowing the air out of one or more outlet openings defined in the face.
18. The method of claim 17 , wherein the air guide structure is attached to the printhead.
19. The method of claim 18 , wherein the air guide structure is removably attached to the printhead.
20. The method of claim 17 , wherein:
the air guide structure is one of a plurality of air guide structures comprising an upstream air guide structure located at an upstream side of the printhead and a downstream air guide structure located at a downstream side of the printhead,
the transporting the print medium comprises transporting a plurality of print media, including the print medium, such that consecutive print media are spaced from each other by an inter-media zone, and
controlling the airflow control system to selectively flow air comprises:
in response to the inter-media zone between the print media reaching a first position relative to the printhead, supplying the air through the opening in the carrier plate from the upstream air guide structure;
in response to the inter-media zone reaching a second position relative to the printhead, ceasing supplying the air from the upstream air guide structure;
in response to the inter-media zone reaching a third position relative to the printhead, supplying the air from the downstream air guide structure;
in response to the inter-media zone reaching a fourth position relative to the printhead, ceasing supplying the air from the downstream air guide structure,
wherein upstream and downstream are defined relative to a direction of the transporting.