JPH04112045A - Ink-jet printer - Google Patents

Abstract

PURPOSE:To prevent the adhesion of dust onto a nozzle section and the drying of ink on non-purging, and to conduct purging by simple constitution on purging by providing a capping device, a purging device and a capping release means releasing capping. CONSTITUTION:When a print head 1 reaches a home position, the printing head 1 is pushed against the front plate 2a of a cap 13, and a nozzle 1a is kept under an airtight state. When a purging command is transmitted over a pushing-member drive 22, an elevating member 21 is lowered, a release section 21a is engaged with a following section 11a, a lever 11 is swing in the clockwise direction against the spring force of a spring 14, and the cap 13 is retreated from the nozzle section 1a. The lower end section of the elevating member 21 pushes a hold-down plate 9 by the lowering of the elevating member 21, and an ink bag 4a is pressed. Ink on the inside is pushed toward the print head 1 and flowed out of the nozzle section 1a, and dust and bubbles and the like in an ink flow path are pushed out and purged. Flowing-out waste ink is absorbed to a waste ink absorbing material 7 along the front plate 2a.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an inkjet printer, and particularly to a printer that performs purging by extruding ink from an ink tank and causing the ink to flow out from a nozzle portion of a print head. .

[Prior Art] Conventionally, in inkjet printers, if printing is not performed for a long time, the ink solvent near the ink ejection port evaporates, increasing the viscosity, and causing ejection failure or clogging. In order to prevent this, the ink ejection port is covered with a cap when not in use, or if the ink is pushed out and bagged, the cap is communicated with the outside to allow the ink to flow out from the nozzle in the capped state. The hole is open. Furthermore, in some cases where the nozzle portion is kept airtight with a cap, the purging is sucked out forward using a suction pump, and the waste ink is disposed of by another means.

[Problems to be Solved] In the conventional technology described above, if the cap is provided with a purging hole, the printer may be used in a place with a lot of dirt or dust, or dry ink must be used. If the nozzle is left for a long period of time in an emergency, it is inevitable that dirt will adhere to the nozzle through the hole in the cap or the ink will dry, resulting in clogging. Further, if a cap is used to airtightly close the nozzle portion, a relatively expensive suction pump for purging and waste ink processing means are required, which not only increases cost but also requires a large space.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an inkjet printer that can make the nozzle part of the print head airtight during non-purging and allow ink to flow out from the nozzle part of the print head by an ink extrusion operation during purging.

[Means for Solving the Problems] In order to achieve the above object, the inkjet printer of the present invention supplies ink from an ink tank to a print head. The apparatus includes a purging device that is activated by a purging command at a home position and performs a purging operation by pushing out ink from an ink tank toward a print head, and a capping release means that releases the capping during the purging operation.

The purging device described above includes a pressing member driving device that operates in response to a purging command, and a pressing member that is moved up and down by the pressing member driving device, and when the pressing member descends, the ink tank is pressurized and ink is pushed out from the ink tank. It may be configured so that

Further, the above purging device may include an air pump that operates in response to a purging command, and may be configured such that the ink tank is pressurized by the supply of air from the air pump and the ink is pushed out from the ink tank.

Further, the above capping device is equipped with a swingable lever having a cap for capping the nozzle section on one end side and a driven section on the other end side. It is equipped with an elevating member that descends and a release portion provided on the elevating member and capable of engaging with a driven portion.The above-mentioned capping release means is provided with a lifting member that descends and a release portion that can engage with a driven portion. The cap may be retracted from the nozzle portion by swinging.

Furthermore, the above-mentioned uncapping means may include a central processing unit that receives an external signal and supplies the capping device with a capping cancellation signal, and also supplies a purging signal to the purging device with a slight delay from the camping cancellation signal. It may be configured as follows.

[Example] Embodiments of the present invention will be described below based on the drawings.

1 and 2 show a first embodiment, in which a print head 1 is mounted on a carriage 3 while being fixed by a block 2. In FIG. The ink tank 4 has a structure in which an ink bag 4a is housed in an ink case 4b, and is detachably mounted on the carriage 3. Print head 1
is provided with an ink supply needle 5, which penetrates a septum 6 attached to the ink case 4b to supply ink in the ink bag 4a. The nozzle portion 1a of the printing head 1 projects further forward than the front plate 2a, which is made of a material with excellent water repellency and is fixed to the front surface of the head mounting block 2. A waste ink absorbing material 7 for collecting waste ink is provided below the front plate 2a. The carriage 3 is guided by a guide shaft 8 and conveyed in a direction perpendicular to the paper surface. The position of the carriage 3 in FIG. 1.2 indicates the home position of the print head 1, and at this position the nozzle portion 1a is capped by a capping device 10, which will be described later, and purging is performed. A window hole 4c is formed in the upper part of the ink case 4b, and a presser plate 9 is placed on the upper surface of the ink bag 4a in the ink case 4b, facing the window hole 4c.

The capping device 10 will be explained. The lever 11 is swingably supported around a shaft 12, and has a cap 1 on one end thereof for capping the nozzle portion 1a.
3 is fixed. Also, a cap 13 is attached to the lever 11.
A spring force provided by a spring 14 acts as a biasing force to bring the nozzle portion 1a into close contact with the nozzle portion 1a. Reference numeral 15 is a stopper pin of the lever 11. The other end of the lever 11 is provided with a driven portion 11a that constitutes a capping release means to be described later. This lever 11 is swung clockwise by a driving means (not shown) against the biasing force of a spring 14 when the printing head 1 moves from the printing position to the home position, and when the print head 1 reaches the home position. The cap 13 is swung counterclockwise by the biasing force of the spring 14 so that the nozzle portion 1a of the rad l can be capped for printing. Also, when the print head 1 moves from the home position to the print position, the lever 11 is temporarily swung clockwise against the biasing force of the spring 14 by a driving means (not shown), so that the cap 13 is moved toward the print position. It is designed so that it does not interfere with the movement of l.

The purging device 20 will be explained. The elevating member 21 is supported so as to be movable up and down toward the ink tank 4, and in this example is a pressing member whose lower end portion can be inserted into and removed from the window hole 4c of the ink case 4b at the home position. The elevating member 21 is driven up and down by a suppressing member driving device 22 that operates in response to a purging command. Lifting member 2
1 is provided with a release part 21a that can be engaged with the driven part 11a of the lever 11, and the driven part 11a and the release part 21a are connected to each other.
This constitutes a capping release means.

The present embodiment is constructed as described above, and when the print head 1 reaches the home position, the cap 13 is pressed against the front plate 2a to maintain the nozzle portion 1a in an airtight state. Therefore, the purging command is the pressing member drive device! When supplied to 22,
The elevating member 21 descends, and in the middle of this descent, the release part 21a
is engaged with the driven portion 11a, the lever 11 swings clockwise against the force of the spring 14, and the cap 13 is retracted from the nozzle portion 1a as shown in the second figure. Furthermore, the lifting member 2
1, its lower end enters through the window hole 4c of the ink case 4b, presses the presser plate 9, and closes the ink bag 4.
Pressure a. Due to this pressurizing force, the internal ink is pushed out toward the printing pad 1 and flows out from the nozzle portion 1a.
Purging is performed by pushing out dust and air bubbles in the ink flow path. The waste ink flowing out from the nozzle part 1a is
The ink passes through the front plate 2a and is absorbed by the waste ink absorbing material 7 below it.

3 and 4 show a second embodiment, in which the elevating member 31 of the purging device 30 is provided with a protruding release portion 31a similar to the above, and a central portion of the elevating member 31 is provided with a release portion 31a, and a release portion 31a similar to the above is provided. A communication hole 31b is provided. A ring-shaped seal rubber 31c is fixed to the lower end of the elevating member 31 for airtightly connecting it to the ink tank 34. The ink case 34b of the ink tank 34 is an airtight case that can communicate with the flow hole 31b and has a through hole 34c that is smaller in diameter than the seal rubber 31c. A drive device 32 that raises and lowers the elevating member 31 is an electromagnetic device that operates in response to a purging command. The purging device 30 also includes an air pump 33 that operates in response to a command supplied when the elevating member 31 is lowered. Further, the capping release means is composed of a release part 31a and a driven part 11a. Other parts that are substantially the same as those in the first embodiment are given the same reference numerals. Since the ink tank 34 is supplied with air from the air pump 33, the ink tank is pressurized by the air pressure and pushes out the ink, so the press plate of the first embodiment is not provided.

In this embodiment, when a purging command is supplied to the drive device 32, the elevating member 31 descends, and during this descent, the release portion 31a engages with the driven portion 11a, causing the lever 11 to swing in the same manner as described above. Then, as shown in the fourth figure, the cap 13 is retracted from the nozzle portion 1a. Furthermore, when the lower end of the elevating member 31 is pressed against the upper surface of the ink case 34b in an airtight state by the seal rubber 31C, the communication hole 31b and the through hole 34c are brought into communication. So air pump 3
3 is given a drive signal, air from the air pump is supplied into the ink case 34b through the circulation hole 31b, and the ink in the ink bag 34a is pushed out toward the print head 1 by the pressurizing force of this air. Parsing is done in the same way.

5 to 7 show a third embodiment, in which the capping device 40 includes two levers.

The lever 41 is swingably supported on a shaft 42, a cap 43 is swingably provided at one end via a cap holder 43a, and a pin 41a serving as a driven part is at the other end. is the provision. The second lever 45 is rotatably supported on a shaft 42, and is biased counterclockwise by a spring 44. Between the pin 41b protruding from the second lever 41 and the pin 45b protruding from the second lever 45, there is a second
A spring 46 for transmitting the clockwise swing of the lever 45 to the second lever 41 is a stopper. The initial position of the second lever 45 is determined by a degree determining member 47.

The capping command is issued upon detecting that the carriage 3 has arrived at the home position.For example, the carriage 3 is provided with a protrusion 3a, and the lever 45 is provided with a protrusion 45a that opposes this protrusion 3a. .

The purging device 50 includes an elevating member 5 that is lowered by a pressing member drive device 52 that operates in response to a purging command.
1, and a release lever 53 which is a release part that swings clockwise about a shaft 54 in conjunction with the lowering of the elevating member 51. The distal end of the release lever 53 can engage with the driven portion 41a. Other parts that are substantially the same as those in the first embodiment are given the same reference numerals.

In this embodiment, when the printing pad 1 at the printing position is conveyed by the carriage 3 and moved to the left as shown in the fifth figure and reaches the home position, the projection 3a of the carriage 3 pushes the projection 45a, 6. Rotate the second lever 45 clockwise as shown.

As a result, the first lever 41 is rotated clockwise via the spring 46, and the nozzle portion 1a is capped by the cap 43. Since the cap 43 is swingably supported by the first lever 41, this capping operation is performed smoothly. Therefore, a purging command is issued to the pressing member drive device 5.
2, the elevating member 51 descends and the release lever 53 swings clockwise. The release lever 53 engages with the driven portion 41a as shown in FIG.
is swung counterclockwise against the spring force of the spring 46.

For this reason, the cap 43 is retracted from the nozzle portion 1a.

The elevating member 51 further descends and pressurizes the ink tank 4 as in the first embodiment, so that ink is pushed out from the ink tank and purging is performed.

8 to 11 show a fourth embodiment, in which a capping device 60 supports a camp 63 by a cap support plate 61, and is movable toward and away from the print head 1 by a camp drive device 62. Other parts that are substantially the same as those in the first embodiment are given the same reference numerals.

As shown in Figure 10, which is a circuit diagram for driving this embodiment, the carriage 3 is connected to a central processing unit (CPU).
) 70 is supplied to a carriage motor 72 and a carriage motor 72 is driven and moved. At the print position, a signal controlled by the CPU 70 is supplied to the feed/gutter drive circuit 73, thereby causing the print head 1 to print. Opportunities for purging the print head 1 include the signal P1 generated when the power is turned on, the signal P2 generated when receiving a signal from an external device such as a computer, and the purging switch when the carriage 3 returns to the home position. This may be due to the reception of various external signals P, such as the signal P3 generated when the terminal is closed.

As shown in Figure 11, such an external signal P or CP
When the signal A is supplied to the CPU 70, the capping release signal a is supplied to the cap drive circuit 74 with a slight delay from the signal P, which causes the cap drive device 62 to operate as shown in FIG. 9 to open the cap 63. It is moved backward and evacuated from the nozzle 1a. Furthermore, after a slight delay from the rise of this capping release signal a, a purging signal SugaCP is generated.
The pressure is supplied from U70 to the pressing member drive circuit 75, which operates the suppressing member drive device 22 to lower the elevating member 21, and performs the same purging operation as in the first embodiment. When purging is completed, the purging signal is cut off and the elevating member 21 is raised, and then the cabling release signal a is cut off and the cap 63 again maintains the nozzle 1a in an airtight state. In addition, when starting the printing operation immediately after purging, the cap 63 is kept open by continuing to supply the capping release signal a as shown by the dotted line in FIG.
The cap 63 may be closed by turning off the capping release signal a after printing is completed.

[Effects] As described above, the present invention makes the nozzle portion airtight during non-purging, thereby preventing dust from adhering to the nozzle portion and drying of ink. Moreover, when 1<-, the capping is released and the ink is flowed out from the nozzle part of the print head by the ink extrusion operation, and purging can be performed with a simple configuration without using a suction pump or the like, and an inexpensive inkjet printer can be provided.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, FIGS. 1 and 2 are cross-sectional views showing the first embodiment, and FIGS. 3 and 4 are cross-sectional views showing the second embodiment.
5 to 7 are partially sectional plan views showing the third embodiment;
Figure 11 shows the fourth embodiment, Figures 8 and 9 are cross-sectional views, and the first
Figure 0 is a circuit block diagram, Figure 11 is an external signal P,
FIG. 3 is a waveform diagram showing a capping release signal a and a purging signal. 1 ・Print head, LA...nozzle part, 4.34・
...Ink tank, 10.40.60...Capping device, 11.41
◆ψ・Lever 11a, 41a・Followed part (capping release means), 13.43・φ・Cap, 20.30.50... Purging device, 21.51・
...Lifting member (suppressing member), 21a, 31a, 53...Release part (capping release means), 22...Press member drive device, 31...Lifting member, 33...Air pump, 70... Central processing unit, P...signal from outside, a...capping release signal, b...purging signal. Above 7-[=2] Fig. Figure 10 Q... Tori is 27M 1st belief b ・lgu - nre γ1tchi

Claims (5)

[Claims] (1) In an inkjet printer that supplies ink from an ink tank to a print head, a capping device that airtightly caps a nozzle portion of the print head at a home position; An inkjet printer comprising: a purging device that performs a purging operation by extruding ink from a tank toward the print head; and a capping release means that releases the capping during the purging action. (2) In claim 1, the purging device includes a pressing member driving device that operates in response to the purging command, and a pressing member that is moved up and down by the pressing member driving device,
An inkjet printer characterized in that the ink tank is pressurized by lowering the pressing member, and ink is pushed out from the ink tank. (3) In claim 1, the purging device includes an air pump that operates in response to the purging command, and the ink tank is pressurized by the supply of air from the air pump, and the ink is pushed out from the ink tank. An inkjet printer characterized by: (4) In any one of claims 1 to 3, the capping device includes a swingable lever having a cap for capping the nozzle part on one end side and a driven part on the other end side. The purging device includes an elevating member that descends in response to the purging command, and a release portion provided on the elevating member and capable of engaging with the driven portion, and the capping release means is configured to move the elevating member downward. An inkjet printer characterized in that, when descending, the release portion engages with the driven portion to swing the lever and retract the cap from the nozzle portion. (5) In any one of claims 1 to 3, the capping release means receives an external signal and supplies the capping device with a capping release signal, and
An inkjet printer comprising a central processing unit that supplies a purging signal to the purging device with a slight delay from the capping release signal.