JP2007313884A5

JP2007313884A5 -

Info

Publication number: JP2007313884A5
Application number: JP2007105265A
Authority: JP
Filing date: 2007-04-12
Publication date: 2010-05-27
Anticipated expiration: 2027-04-12

Claims

A pressure chamber communicating with the nozzle, and at least one ink jet head that discharges ink communicating with the pressure chamber from the nozzle;
Ink accommodates a first pressure source to cause the "energy per unit volume" P1 (Pa) which shall be the basis of the stationary ink atmospheric opening height of the nozzle in the ink,
Ink accommodated and a second pressure source to cause the "energy per unit volume" P2 (Pa), which shall be the basis of the stationary ink atmospheric opening height of the nozzle in the ink,
A first flow path connecting the first pressure source and the pressure chamber;
A second flow path connecting the pressure chamber and the second pressure source;
Control means;
With
When the ratio of the flow path resistance of the first flow path to the flow path resistance of the second flow path is “1: r”, the control unit is configured to perform the “unit volume” at least when ink is ejected from the nozzle. The hit energy “P2 (Pa) is maintained in a relationship of“ P2 = {(1 + r) × Pn} − (r × P1) ”using an appropriate pressure Pn of ink in the vicinity of the nozzle opening.
An inkjet apparatus characterized by that.

2. The ink jet apparatus according to claim 1, wherein the appropriate pressure Pn (Pa) is for maintaining a meniscus shape in which an ink surface in the opening of the nozzle is curved to the inside of the opening.

The inkjet apparatus according to claim 1, wherein the appropriate pressure Pn (Pa) is included in a range of 0 (Pa) to -3000 (Pa).

The loss of "energy per unit volume" of ink caused by flow path resistance of the first and second flow paths exceeds 3000 (Pa) at least during ink ejection from the nozzles. The inkjet apparatus according to 1.

The “energy per unit volume” P1 and the “energy per unit volume” P2 are set to different values, and the first and second flow paths are provided between the first pressure source and the second pressure source. When the ink is caused to flow at a flow rate Q (m ³ / sec) via the first pressure source, the control means displays the “energy per unit volume” P1 as viewed from the first pressure source and the second pressure source. The total flow resistance R (Pa · sec / m ³ ) of the first and second flow paths, the flow rate Q, the ratio “1: r”, and the appropriate ink pressure Pn (Pa) in the vicinity of the nozzle opening. The inkjet apparatus according to claim 1, wherein the control is performed under the condition of “P1 = Q · R / (1 + r) + Pn” based on:

The inkjet head has a plurality of the nozzles, has a first ink connection port on a side close to the first pressure source from each branch point where the nozzle branches from the first and second flow paths, A second ink connection port on the side closer to the second pressure source from the branch point;
Each ratio of each flow path resistance from each branch point to the first ink connection port and each flow path resistance from each branch point to the second ink connection port is equal to each other.
The inkjet apparatus according to claim 1.

The inkjet head is plural,
Each flow path resistance from each branch point branching from the first and second flow paths to the nozzles of each inkjet head to the first pressure source, and each flow path resistance from each branch point to the second pressure source Are equal to each other and are “1: r”.
The inkjet apparatus according to claim 1.

The first pressure source is a first ink tank having a first ink liquid level,
The first ink tank has a first ink port and a second ink port;
The second pressure source is a second ink tank having a second ink liquid level,
The second ink tank has a third ink port and a fourth ink port,
The first ink port and the third ink port are connected to the first and second flow paths,
The second ink port and the fourth ink port are connected to first ink feeding means,
The first ink feeding means includes a detection result of a first liquid level sensor that detects the height of the first ink liquid level, and a detection result of a second liquid level sensor that detects the height of the second ink liquid level. Are made to enter and leave the ink from the second ink port and the fourth ink port so that each has a predetermined height,
The pressure of the first ink liquid surface is Pi1 (Pa), the pressure of the second ink liquid surface is Pi2 (Pa), and the height of the first ink liquid surface with reference to the opening height position of the nozzle is h1. (m), the height of the second ink surface relative to the nozzle opening height position is h2 (m), the density of the ink is ρ (kg / m ³ ), and the gravitational acceleration is g (m / m). s ² ), the “energy per unit volume” P1 and the “energy per unit volume” P2 are “P1 = Pi1 + ρ · g · h1” and “P2 = Pi2 + ρ · g · h2”.
The inkjet apparatus according to claim 1.

The first ink liquid level communicates with a pressure-adjusted first atmospheric pressure source,
The second ink liquid level communicates with a pressure-adjusted second atmospheric pressure source;
The ink jet apparatus according to claim 8.

A pump capable of moving gas between the first atmospheric pressure source and the second atmospheric pressure source;
The ratio of the volume of the first atmospheric pressure source to the volume of the second atmospheric pressure source is r: 1.
The inkjet apparatus according to claim 9.

The first ink feeding means has a second pump capable of moving ink between the first ink tank and the second ink tank,
The first ink tank, the first and second flow paths, the second ink tank, and the second pump constitute a circulation path capable of circulating ink.
The ink jet apparatus according to claim 8.

A main tank containing ink,
A second ink feeding means for transferring ink between the circulation path and the main tank;
Further comprising
The second pump is controlled so that a detection result of the first liquid level sensor becomes a predetermined height,
The second ink feeding means is controlled so that a detection result of the second liquid level sensor becomes a predetermined height.
The inkjet apparatus according to claim 11.

The second ink feeding means includes a fourth ink flow path connecting the main tank and the circulation path, and a first pump provided in the fourth ink flow path. While the detection result is lower than a predetermined height, ink is sent from the main tank in the direction toward the circulation path, and when the second liquid level sensor is higher than the predetermined height, the ink flows from the circulation path to the main tank. The ink jet apparatus according to claim 12, wherein ink is sent in a direction.

“Energy per unit volume” P3 (Pa) of the ink in the main tank with reference to the static ink at atmospheric pressure at the nozzle opening height position, the “energy per unit volume” P1, and the “unit volume” The hit energy “P2” has a relationship of “P1>P3> P2”,
The second ink feeding means communicates with the main tank and is connected to the second ink tank, and a first ink passage is connected to the second ink tank, and a first ink for conducting or blocking control between the second ink tank and the main tank. A valve, a fifth ink flow path that communicates with the main tank and is connected to the first ink tank, and a second valve for conducting or blocking control between the first ink tank and the main tank, While the detection result of the second liquid level sensor is lower than a predetermined height, the first valve is opened, and while the detection result of the second liquid level sensor is higher than a predetermined height, the second valve is opened.
The inkjet apparatus according to claim 12.

The first ink feeding means is
A main tank containing ink,
A third ink feeding means capable of moving ink between the first ink tank and the main tank;
A fourth ink feeding means capable of moving ink between the second ink tank and the main tank;
Have
The third ink feeding means controls the detection result of the first liquid level sensor to have a predetermined height ;
The fourth ink feeding means controls the detection result of the second liquid level sensor to have a predetermined height ;
The ink jet apparatus according to claim 8.

The first ink feeding means includes the second ink port and the second ink port so that the detection result of the first liquid level sensor and the detection result of the second liquid level sensor respectively coincide with the opening height position of the nozzle. The ink jet apparatus according to claim 8, wherein ink is allowed to enter and exit from the fourth ink port.

In the first ink feeding means, the liquid level height position detected by the first liquid level sensor and the liquid level height position detected by the second liquid level sensor are each based on the opening height position of the nozzle. The ink jet apparatus according to claim 8, wherein the ink is allowed to enter and exit from the second ink port and the fourth ink port so as to be “−Pn / (ρ · g)”.

The pressure of the first ink liquid level is atmospheric pressure,
The first ink feeding means is configured so that a liquid level height detected by the first liquid level sensor is “P1 / (ρ · g)” with reference to an opening height position of the nozzle. 2 Make ink enter and exit from the ink port,
The ink jet apparatus according to claim 8.

The pressure of the second ink liquid level is atmospheric pressure,
The first ink feeding means is configured so that the liquid level height detected by the second liquid level sensor is “P2 / (ρ · g)” with reference to the opening height position of the nozzle. Let ink go in and out from the 4th ink port,
The inkjet apparatus according to claim 18.

It further has a radiator that can exchange heat with the outside air,
The first ink tank and the second ink tank, together with the radiator, are disposed at an end portion of the device where the device is in contact with outside air.
The ink jet apparatus according to claim 8.

The inkjet head is disposed obliquely above the first ink tank,
A first supply pipe having a thickness capable of supplying ink upward from the first ink tank and allowing bubbles in the ink to rise together with the ink;
A second flat, which is horizontally disposed above the first supply pipe, supplies the ink from the first supply pipe in the horizontal direction, and has a cross-sectional height that allows bubbles in the ink to move together with the ink. A supply pipe;
A third supply pipe having a thickness capable of supplying ink from the second supply pipe to the inkjet head and allowing bubbles in the ink to descend together with the ink;
The inkjet apparatus according to claim 8, further comprising:

A further reduction mechanism that decelerates the ink flow rate;
The deceleration mechanism is provided in an ink port on the ink inflow side of the first ink port and the second ink port.
The ink jet apparatus according to claim 8.

The speed reduction mechanism includes a separation wall that separates an area where the ink port on the ink inflow side in the first ink tank is provided from an area where other ink ports are provided,
The upper edge of the separation wall is longer than the circumference of the opening of the ink port on the side into which the ink flows,
The deceleration mechanism causes ink to overflow from the upper edge of the separation wall toward a region where another ink port is provided.
The inkjet apparatus according to claim 22.

A pressure chamber that communicates with the nozzle, and at least one inkjet head that ejects ink from the nozzle that communicates with the pressure chamber;
A first pressure source that contains ink and generates “energy per unit volume” P1 (Pa) in the ink based on a stationary ink of atmospheric pressure at the opening height position of the nozzle;
A second pressure source that contains ink and generates “energy per unit volume” P2 (Pa) in the ink based on a stationary ink at atmospheric pressure at the opening height position of the nozzle;
In the inkjet device, wherein the first pressure source, the pressure chamber, and the second pressure source are sequentially connected by the first and second flow paths,
A flow path resistance of a flow path from a branch point that branches from the first and second flow paths to the nozzle to the first pressure source, and a flow path resistance of a flow path from the branch point to the second pressure source. When the ratio of “1: r” is set to “1: r”, at least when ink is ejected from the nozzle, the “energy per unit volume” P2 (Pa) is used as the appropriate pressure Pn of the ink in the vicinity of the nozzle opening. A control method for an ink jet apparatus, characterized by maintaining a relationship of P2 = {(1 + r) × Pn} − (r × P1) ″.

A pressure chamber communicating with the nozzle, and at least one inkjet head that discharges ink communicating with the pressure chamber from the nozzle;
A first pressure source that contains ink and generates “energy per unit volume” P1 (Pa) in the ink based on a stationary ink at atmospheric pressure at the opening height position of the nozzle;
A second pressure source that contains ink and generates “energy per unit volume” P2 (Pa) in the ink based on a stationary ink at atmospheric pressure at the opening height position of the nozzle;
Control means;
A first flow path connecting the first pressure source and a branch point provided between the first pressure source and the second pressure source for supplying ink to the nozzle;
A second flow path connecting the second pressure source and the branch point;
With
When the ratio between the flow path resistance of the flow path from the branch point to the first pressure source and the flow path resistance of the flow path from the branch point to the second pressure source is “1: r”, the control The means is at least “P2 = {(1 + r) × Pn} − (r) using an appropriate pressure Pn of ink in the vicinity of the opening of the nozzle as the energy per unit volume” P2 (Pa) when ink is ejected from the nozzle. × P1) ”
An inkjet apparatus characterized by that.

A pressure chamber communicating with the nozzle, and at least one inkjet head that discharges ink communicating with the pressure chamber from the nozzle;
A first pressure source for containing ink and generating energy per unit volume in the ink based on a stationary ink at atmospheric pressure at the nozzle opening height position;
A second pressure source for containing ink and generating energy per unit volume in the ink based on stationary ink at atmospheric pressure at the opening height position of the nozzle;
A first flow path connecting the first pressure source and a branch point provided between the first pressure source and the second pressure source for supplying ink to the nozzle;
A second flow path connecting the second pressure source and the branch point;
Control means;
With
The control means includes one of the energy per unit volume and the energy per second unit volume, the resistance ratio of the channel resistance of the first channel and the channel resistance of the second channel. From the above, the other of the energy per the first unit volume or the energy per the second unit volume is controlled so that the pressure of the ink in the vicinity of the opening of the nozzle is properly maintained.
An inkjet apparatus characterized by that.