Ink flows from the ink tank to the sub-buffer due to the fluid level difference, and air enters the ink tank through the air passage of the sub-buffer, maintaining the

pressure inside the ink tank constant.

If the ink in the sub-buffer exceeds the predetermined level, the excessive ink flows to the absorbent material under the ink tank.

c) Ink supply from ink supply valve to printhead

Ink is supplied from the ink tank to the printhead by opening the ink supply valve, capping the head, and operating the suction pump.

The ink sucked from the caps flows to the maintenance cartridge or the waste ink absorbent material under the purge unit.

d) Ink supply during printing

During printing, the ink supply vale is held open to allow ink to flow from the ink tank to the printhead constantly due to the negative pressure generated by dis-

charging of ink.

The waste ink used for printhead cleaning and borderless printing flows to the waste ink absorbent materials under the maintenance cartridge and purge unit in

addition to the waste ink box.

If all of ink passages are opened (no ink tank is installed, the ink supply valve is opened, and the printhead fixer lever is opened) when the ink tube is filled with

ink, the ink in the ink tube may reverse-flow due to the fluid level difference and ink may leak from the hollow needle of the ink tank.

Do not open all of the ink passages at the same time when the ink tube is filled with ink.

e) Agitation of ink in the ink tank

Ink in the ink tank is agitated to prevent precipitation of pigment-based ink in the ink tank.

This function is implemented by reverse-flowing ink to the ink tank by opening and closing the supply valve in succession. Inside the ink tank is provided with an

agitation plate to assist agitation of ink. (The agitation plate is also provided in the

- Operation timing: When a new ink tank is installed or when 168 hours have lapsed since the previous agitation (the agitation is performed irrespective of the

whether the printer is printing or cleaning its head)

- Ink supply valve opening/closing count: 30 times (every 30 seconds)

If 336 or more hours have lapsed, the ink valve opening/closing count and the time until the next agitation are changed according to the length of the tame lapsed.

2.3.2.2 Ink Tank Unit

2.3.2.2.1 Structure of Ink Tank Unit

a) Ink tank

Each ink tank contains 130 ml of ink (the starter ink tank supplied with the printer contains 90 ml of ink) for each color. The amount of ink is memorized in the

EEPROM mounted to the ink tank.

The amount of the ink remaining in the ink tank is detected as a dot count according to the data memorized in the EEPROM.

When the electrodes mounted to the hollow needle detect a con-conductive state, a message appears on the display to indicate that the ink is nearly empty. If the

dot count reaches the prescribed value, the ink tank is considered to be empty.

b) Ink port

When the ink tank lock lever is pressed down, the hollow needle enters the ink port (covered with a rubber plug), establishing an ink passage between the printer

and ink tank.

c) Air passage

Mechanical Drive Unit

Ink or air flow

Ink tank

Ink supply valve

Maintenance cartridge

Carriage unit

Joint

Printhead

Suction pump

Cap