Printing apparatus and printing method
AssigneeSCREEN Holdings Co., Ltd.
InventorsKazuhiko Asada, Yasunori Akiyoshi
Life of this patent
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Abstract
An ink is circulated in a circulation path including a supply sub-tank, a discharge head and a collection sub-tank in a head unit. If the amount of the ink in the head unit decreases, the ink stored in the buffer tank is replenished to the head unit. On the other hand, in a first non-replenishment time during which the ink is not replenished, the ink is circulated through the buffer tank, the collection sub-tank and the supply sub-tank in this order. Thus, a temperature fluctuation of the replenishment ink stored in the buffer tank is suppressed. As a result, even if the ink is replenished to the head unit from the buffer tank, physical properties, particularly a viscosity, of the ink do not largely vary.
Claims10
A printing apparatus for replenishing an ink stored in a buffer tank to a head unit including a discharge head configured to print by discharging the ink from a nozzle to a recording surface of a printing medium, the apparatus comprising:
- a supply pipe configured to feed the ink from the buffer tank to the head unit;
- a collection pipe configured to return the ink from the head unit to the buffer tank;
- and
- an ink circulation driver,
- wherein:
- the head unit includes a supply sub-tank and a collection sub-tank in which the ink are stored and a connection pipe connecting the supply sub-tank and the collection sub-tank and circulates the ink by supplying the ink stored in the supply sub-tank to the discharge head, collecting the ink not discharged from the discharge head to the collection sub-tank and returning the ink stored in the collection sub-tank to the supply sub-tank via the connection pipe,
- the supply pipe connects the buffer tank and the collection sub-tank,
- the collection pipe connects the supply sub-tank and the buffer tank, and
- the ink circulation driver circulates the ink along a first circulation path composed of the buffer tank, the supply pipe, the collection sub-tank, the connection pipe, the supply sub-tank and the collection pipe in a first non-replenishment time during which the ink is not replenished.
A printing apparatus, comprising:
- a white drum tank configured to store a white ink;
- a white buffer tank configured to store the white ink replenished from the white drum tank;
- a white head unit configured to print a white image by discharging the white ink supplied from the white buffer tank to a recording surface of a printing medium;
- and
- a white ink circulator configured to circulate the white ink between the white drum tank and the white buffer tank in a second non-replenishment time during which the white ink is not replenished.
A printing method for replenishing an ink stored in a buffer tank to a head unit including a discharge head for printing by discharging the ink from a nozzle to a recording surface of a printing medium, the method comprising:
- printing by discharging the ink to the recording surface of the printing medium from the nozzle of the discharge head while circulating the ink in the head unit by supplying the ink stored in a supply sub-tank to the discharge head, collecting the ink not discharged from the discharge head to a collection sub-tank and returning the ink stored in the collection sub-tank to the supply sub-tank;
- and
- circulating the ink through the buffer tank for storing the ink, the collection sub-tank and the supply sub-tank in this order in a first non-replenishment time during which the ink is not replenished.
A printing method, comprising:
- replenishing a white ink from a white drum tank to a white buffer tank;
- printing a white image by discharging the white ink supplied from the white buffer tank to a recording surface of a printing medium by a white head unit;
- and
- circulating the white ink between the white drum tank and the white buffer tank in a second non-replenishment time during which the white ink is not replenished.
Dependencies are inferred from the claim text.