JP2001063086A - Ink-jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To replenish ink in a full-color recording apparatus in a simple constitution. SOLUTION: A recording head 3 and a sub tank 4 are loaded to a carriage 2. A main tank 11 is set to the side of an apparatus body. An ink feed port of the sub tank 4 is set to a lower position than a nozzle face of the recording head 3. A feed needle 13 is provided which can be connected to an ink replenishment port of the sub tank 4. A guide member 12 coupled to the main tank 11 is set to be movable back and forth to the carriage 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus for supplying ink to a sub tank of a carriage from outside.

[0002]

2. Description of the Related Art In general, as an ink jet recording apparatus used as an image forming apparatus (image recording apparatus) such as a printer, a facsimile, a copying machine, a plotter, etc., a nozzle hole for discharging ink droplets and a discharge chamber in which the nozzle hole communicates. A recording head, which is an ink jet head having a pressure chamber, a pressurized liquid chamber, a liquid chamber, an ink flow path, and the like, and energy generating means for generating energy for pressurizing the ink in the discharge chamber, is mounted on a carriage. , The carriage is moved in the main scanning direction, a recording medium (medium on which ink droplets adhere) is conveyed in the sub-scanning direction, and ink droplets are ejected from the recording head to print an image on the recording medium. Types are known.

In such a serial type ink jet recording apparatus, ink must be supplied to a recording head mounted on a carriage, and generally, an ink cartridge (or ink tank) for supplying ink together with the recording head to the carriage. ).

Although the configuration using the ink cartridge is the simplest, there are problems in increasing the speed, accuracy, efficiency and size of the recording apparatus. That is, since the ink cartridge must be replaced with a new one every time the ink cartridge becomes empty, especially when the ink cartridge is frequently used, the number of times of replacement of the ink cartridge increases, the work becomes complicated, and the ink cartridge must be stored as a spare. Since the number of ink cartridges is increased and the number of waste cartridge containers is increased, running costs and environmental problems are increased.

On the other hand, in order to avoid such a problem,
Increasing the capacity of the ink cartridge increases the weight of the entire carriage, making it difficult to drive the carriage at high speed (high-speed printing), resulting in an increase in the size of the apparatus, and an increase in the output of the carriage drive motor, resulting in cost and noise. A major problem arises in terms of vibration, vibration and the like. Further, since the weight fluctuation of the carriage also increases, the operation characteristics of the carriage change during printing, and it becomes difficult to secure stable printing accuracy.

In order to solve the problem of the ink cartridge system, the ink cartridge is not mounted on the carriage, but the ink cartridge is arranged on the main body of the recording apparatus, and the coupling tube and the small-capacity sub-tank mounted on the carriage are used. There has been proposed a tube suction method for supplying ink by using a tube.

This tube suction method can solve all of the above-mentioned problems in that no ink cartridge is mounted on the carriage, but on the other hand, when high-speed printing is performed, the carriage speed and the like increase. Problems such as the durability of the tube and its joint, the incorporation of air bubbles at the joint, and the fluctuation of the ink supply pressure occur.

Therefore, a main tank is provided on the main body of the recording apparatus, a small-capacity sub-tank is mounted on the carriage, and ink is supplied from the main tank to the sub-tank when the carriage comes to a predetermined position. This is referred to as a “stand supply system”).

For example, Japanese Patent Application Laid-Open No. Hei 5-138899 discloses an ink supply nozzle which connects a main stand and a sub tank so as to be able to move forward and backward, a solenoid which moves this ink supply nozzle forward and backward, and a carriage which comes to a predetermined position. When the solenoid is excited, the ink supply nozzle is moved to the carriage side to supply the ink until the ink full state is detected.

Japanese Patent Application Laid-Open No. 7-47690 discloses that
There is disclosed a main tank disposed below a carriage, a sub-tank disposed above a recording head of the carriage, and a supply pump disposed between a supply port of the sub-tank and the main tank.

Japanese Patent Application Laid-Open No. 8-276600 discloses that an ink supply container is provided at an ink replenishing station, and the ink supply container and a sub tank (cartridge) are provided.
And a fluid connector for connecting the ink supply device and the ink supply container is provided so as to be movable up and down, and the fluid connection device is moved down at an ink replenishment station so as to be connected to the cartridge to replenish the ink from the ink supply container to the cartridge. .

Japanese Patent Application Laid-Open No. 9-240020 discloses an ink tank for storing an ink for replenishment, an ink replenishing means for communicating the ink tank with a sub-tank (ink chamber). Is disclosed in which the ink replenishing nozzle is moved downward to connect to the ink chamber to replenish the ink from the ink tank to the ink chamber.

[0013]

As described above, the main tank is provided on the main body of the recording apparatus, and a small-capacity sub-tank is mounted on the carriage, and the main tank is provided only when the carriage comes to a predetermined position. In the case of the stand supply system for supplying ink from the tank to the sub-tank, the carriage operates freely during the printing operation, so that the problem that occurs in the tube suction system does not occur.

However, in the ink jet head, a structure for securing an ink meniscus on the nozzle surface of the head is required. However, such a point has not been solved by the above-described conventional apparatus.

In the apparatus disclosed in Japanese Patent Application Laid-Open No. 7-47690, the main tank is disposed below, and a supply pump is required to supply ink.
This supply pump is different from the pump for suctioning from the cap side in the head reliability maintenance / recovery mechanism, and requires two pumps.

Further, in the apparatuses disclosed in JP-A-8-276600 and JP-A-9-240020, since the ink is replenished from above the carriage, the size of the entire recording apparatus increases in the height direction. In particular, there is a problem that it is difficult to apply to a printing apparatus that performs full-color printing using three or four or more colors of ink.

The present invention has been made in view of the above points, and has as its object to solve the problems in the stand supply system.

[0018]

In order to solve the above-mentioned problems, an ink jet recording apparatus according to the present invention has a structure in which an ink supply port of a sub-tank is positioned lower than a nozzle surface of a recording head.

Further, the ink jet recording apparatus according to the present invention has a supply means which can be connected to the ink supply port of the sub-tank, and a guide member connected to the main tank is provided so as to be able to advance and retreat with respect to the carriage. Things.

Further, the ink jet recording apparatus according to the present invention has a supply means in which the ink supply port of the sub-tank is lower than the nozzle surface of the recording head and which can be connected to the ink supply port of the sub-tank. The guide member connected to the tank is provided so as to be able to advance and retreat with respect to the carriage.

Here, a guide member of each color can be provided corresponding to a recording head composed of a head of each color. In this case, it is preferable that the guide member of each color has a supply unit at a position corresponding to the head of each color. Further, it is preferable that the supply unit is connected to the ink supply port of the sub-tank by the guide member abutting on the carriage. further,
It is preferable that the ink supply port of the main tank is located at a position higher than the nozzle surface of the recording head.

It is preferable that the ink supply port of the sub-tank is sealed with a ball urged from the inside to the outside.

[0023]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 is an explanatory side view of a main part of an ink jet recording apparatus to which the present invention is applied, FIG. 2 is an explanatory plan view of FIG. 1, FIG. 3 is an explanatory sectional view illustrating details of a sub tank and a guide member in a separated state, and FIG. It is sectional explanatory drawing explaining the detail of a sub tank and a guide member similarly in a connection state.

In this ink jet recording apparatus,
The main support guide rod 1 and the auxiliary support guide rod (not shown) are horizontally suspended between the side plates (not shown) in a substantially horizontal positional relationship, and the carriage 2 is moved by the main support guide rod 1 and the auxiliary support guide rod in the main scanning direction ( (In the direction of the arrow in FIG. 2).

A head 3k of each color, which is an ink jet head for discharging ink droplets,
A recording head 3 comprising 3y, 3m, 3c is mounted, and a sub-tank 4 for supplying ink of each color to the heads 3k, 3y, 3m, 3c of each color (sub-tanks 4 of each color are denoted by 4k, 4y, 4m, 4c) is mounted. Each sub-tank 4 and each head 3 are connected (communicated) by a pipe or tube 5.

Here, by arranging each sub-tank 4 below the carriage 2, the ink supply port 4 a for the head of each sub-tank 4 is connected to the nozzle surface 3 a of the head 3.
Lower position.

Each sub-tank 4 is provided with a detecting means for detecting the remaining amount of ink. As this detection means, for example, a means that embeds metal pins at upper and lower positions of the sub tank 4 and detects an ink full state and an ink near empty state (or an ink end state) by detecting a voltage difference can be used. .

The carriage 2 is a drive pulley (drive timing pulley) rotated by a main scanning motor (not shown).
The carriage 2 is moved in the main scanning direction by controlling the driving of a main scanning motor by connecting to a timing belt 6 stretched between the motor and a driven pulley (idler pulley).

Further, a reliability maintenance / recovery mechanism 8 having a cap means 7 for capping the nozzle surface 3a of the head 3 and the like is provided at the end of the carriage 2 in the main scanning direction. The cap means 7 is connected to an atmosphere opening tube 9 and a suction tube 10 connected to a suction pump.

In the main scanning direction where the reliability maintenance / recovery mechanism 8 is provided, a main tank 11 of each color for replenishing ink to the sub-tanks 4k, 4y, 4m, and 4c of each of the recording heads 3 is provided. (Code 11k for each color,
11y, 11m, and 11c. ). The main tank 11 is provided at a position where the ink supply port 11 a is higher than the nozzle surface 3 a of the head 3.

The guide members 12 of each color which can be engaged with both side portions of the carriage 2 (the guide members of each color
They are denoted by k, 12y, 12m, and 12c. ) Is provided so as to be able to advance and retreat with respect to the carriage 2 at the supply position.

Each of the guide members 12 has a sub-tank 4
Supply needles 13 (supply needles of respective colors are denoted by reference numerals 13k, 13y, 13m, and 13c).
And is connected to the main tank 11 via a pipe or tube 14. Here, the supply needle 13k,
13y, 13m, and 13c are heads 3 of each color.
k, 3y, 3m, and 3c.

Here, a replenishing mechanism of the supply needle 13 of the guide member 12 and the sub-tank 4 will be described with reference to FIGS. First, the sub-tank 4 houses a porous ink holding member (ink absorber) 22 in a case 21, and forms a cylindrical ink supply port 23 integrally with the case 21. The ink supply port 23 has a supply port 24 formed at the tip (rear side), and a sealing portion 26 protruding inward on the inner wall surface of the entrance 25.

In the ink supply port 23, a ball 27 for sealing (sealing) the sealing portion 26 is provided, and a spring 28 having the ball 27 provided therein is attached outward. By urging, the ball 27 is pressed against the sealing portion 26 and the inlet portion 25 of the ink supply port portion 23 is always sealed. By pushing the ball 26 inward against the urging force of the spring 27, the inlet 25 is opened, and ink can be supplied from the supply port 24 to the ink holding member 22.

On the other hand, a cylindrical case portion 31 is formed in the guide member 12, and a hollow supply needle 13 is inserted into the cylindrical case portion 31 so as to be able to advance and retreat. The space between the outer tank and the outer peripheral surface is sealed by a seal member 32, and a tube 14 connected to the main tank 11 faces a space formed inside the seal member 32. Supply needle 1
3 has a sealing member 32 connected to the sub tank 4.
An ink supply hole 33 is formed at a position on the deeper side.

A spring 34 for urging the supply needle 13 in the advance direction is provided in the case 31. Then, in order to prevent the supply needle 13 from coming off from the case portion 31, a rib 35 is formed on the outer peripheral surface of the supply needle 13, and the guide member 12 is provided with the rib 35 of the supply needle 13 on the front side and the rear side in the advancing direction. A stopper member 36 is provided, which can be engaged with and controls the range of movement of the supply needle 13.

Next, the outline of the control section of the ink jet recording apparatus will be described with reference to FIG. The control unit includes a microcomputer (hereinafter, referred to as a “CPU”) 40 that controls the entire recording apparatus, a ROM 41 that stores necessary fixed information, a RAM 42 that is used as a working memory, and the like. An image memory 43 for storing the processed data, and a parallel input / output (PI
O) port 44, input buffer 45, gate array (GA) or parallel input / output (PIO) port 46
And a head drive circuit 47 and drivers 48, 49, 50
Etc. are provided.

Here, in addition to image information from the host side, data such as paper type data indicating the type of paper, various instruction information from an operation panel (not shown),
As shown in FIG. 1, each detection signal from an ink full sensor (detection pin) 51 and an ink near-end sensor (detection pin) 52 provided in the sub-tank 4, a detection signal from a paper presence / absence sensor for detecting the start and end of the paper, Signals and the like from various sensors such as a home position sensor for detecting the home position (reference position) of the carriage 3 are input, and necessary information is sent to the host and the operation panel through the PIO port 44. You.

The head driving circuit 47 generates energy corresponding to each nozzle of the recording head 3 (piezoelectric element for the piezo type, heat generation for the bubble type) based on various data and signals given through the PIO port 46. A drive waveform or the like is applied to a resistor or an electrode or a diaphragm in an electrostatic type.

The driver 48 controls the driving of the main scanning motor 53 for moving the carriage 2 in the main scanning direction and the sub-scanning motor 54 for transporting the paper in accordance with the driving data given via the PIO port 46, respectively. The carriage 2 is moved and scanned in the main scanning direction to convey a predetermined amount of paper.

The driver 49 is connected to the PIO port 46.
The solenoid (SOL) 55 for moving the guide member 12 forward and backward is driven in response to the guide member forward / backward signal given through the control unit. Further, the driver 50 controls the drive of the suction pump 56 of the reliability maintenance / recovery mechanism 8 in accordance with the suction pump drive signal given via the PIO port 46 to release the air and perform ink suction.

Next, the operation of the ink jet recording apparatus will be described with reference to FIG. First, as shown in FIG. 1, since the ink supply port 4a of the sub tank 4 is located at a position lower than the nozzle surface 3a of the recording head 3, a head difference H occurs between the recording head 3 and the sub tank 4. As a result, a constant negative pressure is always obtained, an ink meniscus surface can be formed on the nozzle, and stable ink droplet ejection becomes possible. In particular, when a foam body (porous body) is used for the sub-tank 4, a negative pressure can be generated due to a decrease in ink.

Next, the connection operation between the sub tank 4 and the supply needle 13 of the guide member 12 will be described with reference to FIGS. When the guide member 12 is advanced from the state shown in FIG. 3, the tip of the supply needle 13 abuts against the ball 27 of the sub-tank 4, and the biasing force of the spring 28 is made larger than the biasing force of the spring 34 at this time. Needle 13 is relatively pushed into case portion 31 against spring 34.

Then, by further advancing the guide member 12, the front end portion 36a of the stopper portion 36 of the guide member 12 comes into contact with the side surface of the sub-tank 4 as shown in FIG. At this time, the supply needle 13 enters the ink supply port 23 while pushing the ball 27 against the urging force of the spring 28 of the sub tank 4, and the ink supply hole 33 of the supply needle 13 is connected to the main tank 11. Corresponding to the opening of the tube 14.

Thus, the main tank 11 is normally open to the atmosphere, and the supply needle 13 is connected to the sub-tank 4 as shown in FIG. The ink flows into the sub-tank 4 from the supply port 24 of the ink supply port 23 of the sub-tank 4 via the needle 13, and ink is supplied to the sub-tank 4.

Next, the ink supply operation to the sub-tank 4 will be described with reference to FIG. 6. When the carriage 2 is at the standby position (reliability maintenance / recovery mechanism side), the detection signal of the ink near-end sensor 51 is checked. To determine whether the state is the ink near end state. This determination is made for the sub-tank 4 of each color. Further, instead of the ink near end, an ink end state may be detected and determined.

Then, in the ink near end state,
The sub tank 4 of the color in the ink near end state moves the carriage 2 to a position corresponding to the guide member 12 of the color. Thereafter, the guide member 12 is advanced. At this time, since the supply needles 13 are provided on the respective guide members 12 corresponding to the positions of the sub-tanks 4 of the respective colors of the carriage 2, by moving the guide members 12 forward, the supply needles 13 of the guide members 12 of the corresponding colors are provided. Is the sub tank 4 of the color
Is supplied to the ink supply port 23 for ink supply. The guide member 12 is a guide member 1 of a color to be supplied.
2 may be moved, or the whole may be moved integrally.

The detection signal of the ink full sensor 51 is checked to determine whether or not the ink is full (ink replenishment is completed).
The guide member 12 is retracted, and the carriage 2 returns to the standby position. When the inks of a plurality of colors have reached the ink near end state, the carriage 2 is moved to a position corresponding to the guide member 12 of the color to be replenished next.

Next, another embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In this embodiment, the main tank 11 and the guide member 12 of four colors are arranged at both ends in the main scanning direction for each of two colors, so that the space can be effectively used.

In the above embodiments, the sub-tanks of each color are arranged in the main scanning direction. However, the sub-tanks may be arranged in the vertical direction. In this case, the guide members of each color are also arranged in the vertical direction. . With this configuration, the width in the main scanning direction can be reduced, and ink can be supplied to the sub tank in a state where the nozzle surface of the head is capped by the cap unit. However, in this case,
In order to select the color to be replenished, it is necessary to use a mechanism for independently moving the guide member of each color.

[0051]

As described above, according to the ink jet recording apparatus of the present invention, the ink supply port of the sub tank is located at a position lower than the nozzle surface of the recording head.
A constant negative pressure is always obtained, an ink meniscus of the nozzle can be formed, and stable ink droplet ejection can be performed.

Further, the ink jet recording apparatus according to the present invention has supply means which can be connected to the ink supply port of the sub tank, and the guide member connected to the main tank is provided so as to be able to advance and retreat with respect to the carriage. Restrictions on the position and size of the tank can be reduced, and for example, it can be shared with a monochrome engine.

Further, the ink jet recording apparatus according to the present invention has a supply means in which the ink supply port of the sub-tank is lower than the nozzle surface of the recording head and which can be connected to the ink supply port of the sub-tank. Since the guide member connected to the tank is provided so as to be able to advance and retreat with respect to the carriage, stable ink droplet ejection can be performed, and restrictions on the position and size of the main tank can be reduced.

Here, color recording can be performed by providing guide members of each color corresponding to recording heads composed of heads of each color. In this case, erroneous replenishment can be prevented by providing the supply member at a position corresponding to the head of each color for the guide member of each color. Further, the supply means is connected to the ink supply port of the sub-tank by bringing the guide member into contact with the carriage, so that the supply member can be connected to the sub-tank only by moving the guide member forward and backward, thereby reducing costs. be able to.

Further, by setting the ink supply port of the main tank at a position higher than the nozzle surface of the recording head, replacement becomes easy, ink can be supplied without using a pump or the like, and the cost is reduced. .

Further, since the ink supply port of the sub-tank is sealed by a ball urged from the inside to the outside, the inside of the sub-tank can be sealed with a simple configuration, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory side view of a main part of an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is an explanatory plan view of FIG. 1;

FIG. 3 is an explanatory sectional view illustrating details of a sub tank and a guide member in a separated state;

FIG. 4 is an explanatory cross-sectional view illustrating details of a sub tank and a guide member in a connected state.

FIG. 5 is a block diagram showing an outline of a control unit of the recording apparatus.

FIG. 6 is a flowchart illustrating an ink supply operation.

FIG. 7 is an explanatory plan view showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main guide rod, 2 ... Carriage, 3 ... Recording head, 3k, 3y, 3m, 3c ... Head, 4 ... Subtank, 5 ... Tube, 11 ... Main tank, 12 ... Guide member, 13 ... Supply needle.

Claims (8)

[Claims] 1. An ink jet recording apparatus comprising: a recording head and a sub-tank for supplying ink to the recording head mounted on a carriage; and a main tank on an apparatus main body side for supplying ink to the sub-tank. An ink jet recording apparatus, wherein a supply port is located at a position lower than a nozzle surface of the recording head. 2. An ink jet recording apparatus comprising: a recording head and a sub-tank for supplying ink to the recording head mounted on a carriage; and a main tank for replenishing the sub-tank with ink on an apparatus main body side. An ink jet recording apparatus, comprising: a supply unit connectable to a supply port, and a guide member connected to the main tank is provided so as to be able to advance and retreat with respect to the carriage. 3. An ink jet recording apparatus comprising: a recording head and a sub-tank for supplying ink to the recording head mounted on a carriage; and a main tank for replenishing the sub-tank on an apparatus main body side. The supply port is located at a position lower than the nozzle surface of the recording head, and has supply means connectable to the ink supply port of the sub-tank, and moves the guide member connected to the main tank with respect to the carriage. An ink jet recording apparatus characterized by being provided as possible. 4. The ink jet recording apparatus according to claim 2, wherein the guide members of each color are provided corresponding to the recording heads of each color. 5. The ink jet recording apparatus according to claim 4, wherein the guide member of each color has the supply unit at a position corresponding to a sub tank of the head of each color. 6. The ink jet recording apparatus according to claim 2, wherein the supply unit is connected to the sub tank by bringing the guide member into contact with an outer surface of a carriage or a sub tank. Ink jet recording device. 7. The ink jet recording apparatus according to claim 1, wherein an ink supply port of the main tank is located at a position higher than a nozzle surface of the recording head. 8. The ink jet recording apparatus according to claim 1, wherein the ink supply port of the sub-tank is sealed with a ball urged from inside to outside. Ink jet recording device.