JPH1067122A - Ink jet type image forming apparatus and ink suction pump used for the same - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide an ink jet type image forming apparatus that can efficiently suck ink in a suction operation and does not increase the size of the apparatus. . The present invention provides a recording head having a plurality of nozzles (3b, 3c), a plurality of cap members (9c, 9d) covering the nozzles (3b, 3c), and suction of ink in the cap members (9c, 9d). Ink suction pump 17
In the image forming apparatus of the ink jet type having the above-described configuration, the ink suction pump 17 includes: a cylinder 20 having two ink suction ports 21 and 22;
And pistons 24 and 37 movably disposed in the inside of the ink jet system. The pistons 24 and 37 are moved in the cylinder 20 to generate different suction pressures in the ink suction ports 21 and 22. An image forming apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a small printer, and more particularly, to an ink jet type image forming apparatus for forming an image by causing ink to fly on a recording medium such as a sheet of paper, and used in the image forming apparatus. It relates to an ink suction pump.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus of the ink jet type comprises, for example, a recording medium conveying member for conveying a sheet or the like in a fixed direction, And a recording head carriage that is provided so as to be movable in a direction perpendicular to the recording medium and that causes ink to fly from a nozzle portion toward a conveyance path of the recording medium. Note that the recording head carriage is generally a full-color carriage capable of flying yellow ink, magenta ink, cyan ink, and black ink, and is provided for each color in the full-color carriage. Generally has a plurality of recording heads each including a nozzle portion and an ink tank. In addition, while each of the nozzle portions has a large number of nozzles, each of the ink tanks is detachably mounted on the recording head carriage.

The ink jet type image forming apparatus conveys a recording medium by a recording medium conveying member, and causes ink to fly according to image information while the recording head carriage is reciprocated. Then, a predetermined image is formed on the recording medium.

[0004] By the way, the image forming apparatus of the ink jet system uses ink, and further forms an image by causing the ink to fly from the nozzle portion, thereby maintaining image quality. There are various problems in doing so.

More specifically, in the above-described ink jet type image forming apparatus, first, the ink contained in the nozzle portion easily dries during non-image formation, and when the state occurs, the viscosity of the ink changes. Do (for example, thicken)
There is a problem that the manner of the flight changes, and a desired image cannot be formed.

Second, in the above-mentioned ink jet type image forming apparatus, the ink is further dried and the thickened ink is clogged in the nozzle portion, or foreign matter or air is mixed in the nozzle portion. Then, there is a problem that the ink does not fly.

Third, in the above-described ink jet type image forming apparatus, since the surface of the ink is dry immediately after the start of the image formation, the flying of the ink is not stable, and the image is appropriately formed. May not be possible.

Fourth, in the above-described ink jet type image forming apparatus, when the ink tank is separated from the recording head and replaced, it is necessary to refill the nozzle portion with ink after the replacement.

Therefore, conventionally, in the above-mentioned ink jet type image forming apparatus, a plurality of cap members for covering the above-mentioned nozzle portions to prevent drying of the ink during non-image formation,
A plurality of ink suction pumps for sucking ink from each cap member are provided. In the image forming apparatus, drying of the ink can be prevented by covering the nozzles with the cap members, and by sucking the ink with the cap members covering the nozzles. The thickened ink and the like can be removed from the nozzle section, and furthermore, by causing the ink to fly from each nozzle section immediately before the start of image formation, it is possible to prevent uneven flight of ink that occurs at the start of image formation. Hereinafter, the former is called a capping operation, the middle is called a recovery operation, and the latter is called a dummy jet operation.

By the way, in such an ink jet type image forming apparatus, each cap member is generally configured to perform maintenance of a nozzle facing the cap member. However, in this configuration, each pump sucks in order to suck foreign matter in the nozzles and refill the inks in the nozzles. Must be aspirated. Then, in order to suck foreign matter in the nozzle and refill ink, the pump may apply a suddenly high suction pressure to the nozzle. On the other hand, in order to suck the ink that has been hit by the test and accumulated in the cap member, the pump may suck the ink over a long period of time.

Therefore, in the above configuration, the ink suction characteristics of the pump cannot be matched to all of these suction operations, and it is not possible to efficiently suck ink in at least one of the suction operations.

In order to eliminate the problem, it is conceivable to provide a pump having a suction characteristic suitable for each suction operation for each suction operation. However, in such a configuration, the exclusive space of the pump is dramatically increased. .

[0013]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems, and has been made in consideration of the above-described problems. It is an object to provide an apparatus and an ink suction pump used for the apparatus.

[0014]

That is, the present invention relates to a recording head having a plurality of nozzles for ejecting ink in accordance with image information, a plurality of cap members covering the nozzles, and a connection to the cap member. An ink-jet type image forming apparatus having an ink suction pump that sucks ink in the cap member, wherein the ink suction pump has a cylinder having an internal space and two ink suction ports communicating with the internal space, An ink jet type image forming apparatus having a piston movably disposed in the internal space and generating a different suction pressure at each ink suction port by moving the piston within the cylinder.

According to another aspect of the present invention, there is provided a cylinder having an internal space and two ink suction ports communicating with the internal space, and a piston movably disposed in the internal space. This is an ink suction pump for an ink-jet type image forming apparatus that generates different suction pressures at each ink suction port by moving the ink in the cylinder.

In the present invention, the above-mentioned nozzle portion is a portion for flying ink, and generally has a structure in which a number of nozzles are formed. Further, even if all of the nozzles of the nozzle unit are configured to fly one type of ink, all the nozzles are configured to fly different colors of ink for each predetermined group. Is also good.

The cap member only needs to cover the nozzle portion. For example, a concave portion is formed in a surface (hereinafter, referred to as a front surface) facing the nozzle portion, and a side surface is formed from the concave portion. , A cap made of rubber having a communication hole penetrating therethrough, an ink holder such as a sponge provided in the recess, and a cap case in which the cap is housed. In this configuration example,
Since the recess and the outside air are communicated with each other through the communication hole, the pressure in the ink tank and the pressure in the recess should always be matched when covering the nozzle portion or while covering the nozzle portion. This prevents the ink from leaking out of the nozzle portion and the ink from being pulled into the nozzle portion.

The term “covering” does not only mean a state where the periphery of the nozzle portion is completely covered with the cap member, but also a case where the ink inside the nozzle portion is sufficiently covered to prevent drying. Including.

In an ink jet type image forming apparatus having a plurality of nozzle portions, each nozzle portion may be covered with a cap member, or the plurality of nozzle portions may be covered with one cap member.

The ink suction pump comprises a cylinder having an internal space and two ink suction ports communicating with the internal space, and a piston movably disposed in the internal space. Any pressure that can generate a different suction waveform pressure at each ink suction port by moving within the ink suction port may be used. Thus, the ink can be always sucked while the cylinder is reciprocating, so that the ink can be sucked with twice the efficiency. Each space formed on the left and right sides of the cylinder by partitioning the inside of the cylinder with a piston is called a suction chamber.

In the ink-jet type image forming apparatus of the present invention, one ink suction pump is provided with two ink suction ports, and different suction pressures are generated in each ink suction port. Ink can be sucked with suction characteristics corresponding to the suction operation.

Further, in the image forming apparatus, the ink suction pump is connected to the internal space and the internal space.
Since it is composed of a cylinder having two ink suction ports and a piston movably arranged in the internal space, the space occupied by the ink suction pump can be reduced.

In the present invention, it is preferable that the ink suction pump applies a suddenly high suction pressure to the nozzle in order to suck foreign matter in the nozzle or refill ink. On the other hand, in order to suck ink accumulated in the cap member, it is preferable to suck ink over a long time.

In order to generate the former suction pressure, for example, the ink suction port is formed near the center of the cylinder, and after the piston has moved to some extent, the ink suction port and the cylinder communicate with each other. Alternatively, a sealing valve may be provided at the ink suction port to open the sealing valve after the piston has moved to some extent.

On the other hand, in order to generate the latter suction pressure, for example, the ink suction port is formed near the end of the cylinder, and the ink suction port is always connected to the suction chamber in the cylinder regardless of the position of the piston. And may be configured to communicate with each other.

In the present invention, if the initial capacities of the suction chambers at the start of suction are made different, the maximum value of the pressure generated in each suction chamber can be made different. And
For example, when generating a high suction pressure, the initial capacity at the start of the suction chamber suction may be set small.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the image forming apparatus of the present invention will be described below in detail with reference to the accompanying drawings.

Embodiment 1 FIG. 1 shows an image forming apparatus of an ink jet system according to the present embodiment. The image forming apparatus includes a recording medium conveying member 1 that conveys a recording medium P in a certain direction, and extends in a direction opposite to a conveying path of the recording medium P and perpendicular to the conveying direction of the recording medium P. A set of guide members 2, a recording head carriage 3 supported by the guide members 2, and a maintenance station 4 disposed below the guide members 2 and at a position adjacent to the recording medium transport path.
And a housing for holding these together. Further, image information is sent to the recording head carriage 3 through a signal line formed on a flexible substrate, and a home position of the recording head carriage 3 is set at a position facing the maintenance station 4. The position is detected by the home position sensor 7.

As shown in FIG. 2, the recording head carriage 3 includes a head carriage frame 3a movably disposed on the pair of guide members 2, and a lower surface of the frame 3a (the recording medium transport path). , Two nozzle portions 3b arranged so as to project below
3c, and two ink tanks 3d and 3e detachably mounted on the frame 3a and supplying ink to the nozzles 3b and 3c.

A large number of nozzles are formed in each of the nozzle portions 3b and 3c. Then, on one side 3b (right side in the figure) of the nozzle portion, the nozzle portion 3
Since the ink tank 3d connected to b supplies black ink, one type of ink flies according to image information,
On the other hand, at the other side 3c (left side in the figure) of the nozzle section, the ink tank 3e connected to the nozzle section 3c supplies yellow ink, magenta ink, and cyan ink. Can fly. In the drawings according to the present embodiment, a plurality of nozzles for each color are shown as one nozzle for convenience (a plurality of nozzles (nozzle group) for black are 3f, and a plurality of nozzles for yellow are 3g). , The number of nozzles for magenta is 3h, and the number of nozzles for cyan is 3i).

As shown in FIG. 3, the image forming apparatus conveys the recording medium P by the recording medium conveying member 1 and reciprocates the recording head carriage 3 according to the image information. A predetermined image is formed on the recording medium P by causing the ink to fly.

The maintenance station 4 is provided as shown in FIG.
As shown in the figure, the station main body 4a and a discharged ink absorber 4b for absorbing and holding the ink discharged from the station main body 4a.

As shown in FIG. 5, the station main body 4a comprises a unit housing 8 and various members attached thereto.

In FIG. 5, reference numeral 9a denotes an ink holder formed of sponge, and 9b denotes the ink holder 9a.
9c formed with a recess for accommodating therein, and a communication hole 9f penetrating from the recess to the side surface.
Is a cap case for accommodating the cap 9b, and the cap member 9 is formed by these. Also,
The station body 4a has two cap members 9c,
9d, which are held on the cap carriage 10.

The cap carriage 10 has a support bottom plate 10a for supporting the two cap members 9c and 9d.
And a pair of arm portions 10b disposed at both ends of one side thereof
And a guide portion 10 disposed below the support bottom plate 10a.
c and the guide portion 10 below the support bottom plate 10a and
c, the arm 10b and the guide 10c are engaged with the unit housing 8 and the fulcrum 10d is L-shaped as shown in FIG. The arm 11 is connected, and the L-shaped arm 11 can be moved up and down while maintaining a constant posture by swinging the L-shaped arm 11 by the cam 12a. Hereinafter, the member on which the cam 12a is formed is referred to as a cam drive transmission member 12.

As shown in FIG. 7, the cap carriage 10 is provided so as to be movable in the same direction as the recording head carriage 3 (hereinafter, also referred to as the left-right direction). Force is applied in the direction.

Further, the recording head carriage 3 has two projections 14a and 14b formed at positions adjacent to the two nozzles 3b and 3c, while the cap carriage 10 has the two projections 14a. , 14b is disposed at a position corresponding to the movement path of the moving member 14b, and a fixed pin 15 is disposed on the station body 8 near the engaging pin 14c and movably in the vertical direction. .
As shown in FIG. 8, the fixing pin 15 is urged upward by a spring 16 inserted between the fixing pin 15 and the unit housing 8 and engages with the gear groove of the cam drive transmission member 12. Then the height is set.

Then, as shown in FIG. 7, the station main body first raises the cap carriage 10 to a height at which the engaging pin 14c and the projection 14a can be engaged (see FIG. 7B). Next, the recording head carriage 3 is moved to the left to engage the engaging pin 14c with the right protrusion 14a, and the cap carriage 10 is further moved slightly to the left (see FIG. 3C). Further, the cap carriage 10 is raised to move the cap members 9c and 9d.
Is pressed against the nozzle portions 3b and 3c (see FIG. 4D), so that the capping can be surely performed. Further, in the station body 4a, when the cap members 9c, 9d are pressed against the nozzle portions 3b, 3c, the fixing pins 15 are raised to engage the left convex portions 14b, whereby the two convex portions are engaged. The recording head carriage 3 can be fixed by inserting the engaging pin 14c and the fixing pin 15 between the portions 14a and 14b.

In FIGS. 5 and 9, reference numeral 17a
Is the ink suction pump, 17b is the ink suction pump 1
7a and two hoses connecting the cap members 9c and 9d. These hoses form an ink suction pump member 17, and the one ink suction pump 17a sucks the ink in the cap members 9c and 9d. It has become. Also, the outlet 23 of the ink suction pump 17a
Is connected to a drain ink conductor 18, and the drain ink conductor 1
8, the ink is discharged to the discharged ink absorber 4b.

As shown in FIG. 10, the discharged ink conductor is connected to the ink suction pump 17a and the discharged ink absorber 4b.
Is disposed at a substantially horizontal position, and the sponge 18b is provided at the discharge port of the discharge ink conductor so that the discharge ink does not drip when the discharge ink absorber 4b is replaced.
Are arranged.

As shown in FIG. 11, the ink suction pump has two ink suction ports 21 and
22 is formed, and an ink discharge port 23 is formed at the lower center of the center so as to easily discharge the ink. Hereinafter, the ink suction port 21 connected to the right cap member 9c is referred to as a right ink suction port, and the ink suction port 22 connected to the left cap member 9d is referred to as a left ink suction port. As shown in FIG. 12, a piston head 37 formed in the cylinder 20 to have a size in contact with the inner peripheral surface of the cylinder 20 and having a through hole 26 formed in a central portion thereof, A piston including a piston rod 24 formed to have a smaller diameter d ₂ (<d ₁ ≒ d ₁ ′) than the through hole 26 is provided.

More specifically, the piston head 37 is provided with a pair of silicone rubber piston rings 25 at both ends of the peripheral surface thereof, and has ink flow passages communicating with the through holes 26 on the side surfaces therebetween. An outlet 27 is formed.

More specifically, the piston rod 24
It is formed in a size to close the through hole 26 of the piston head.
And a pair of sealing members 28, and the two sealing portions
The material 28 has a length l of the through hole 26 of the piston head.₁Yo
A little longer interval l_Two(> L ₁)
You. Further, each sealing member 28 is made of silicone rubber.
Become. Then, the piston rod 24 is driven by the drive transmission arm.
Through the cam 19 to the cam of the cam drive transmission member 12.
Is tied.

The ink suction pump 17a is
As shown in FIG. 13, when the piston rod 24 is pulled, ink is sucked from the ink suction port 21 on the right side, and the discharged ink stored in the left side 29 of the piston is discharged to the through hole 26 and the ink outlet. The ink is discharged from the ink discharge port 23 through the ink discharge port 27. Further, as shown in FIG. 14, the ink suction pump sucks ink from the left ink suction port 22 by pushing back the piston rod 24, and discharges ink discharged from the right side 30 of the piston. The ink is discharged from the ink outlet 23 through the through hole 26 and the ink outlet 27. Note that the initial capacity at the start of suction of the suction chamber communicating with the right ink suction port 21 means the capacity of the suction chamber in the state shown in FIG. 13B. The initial capacity of the suction chamber communicating with the left ink suction port 22 at the start of suction means the capacity of the suction chamber in the state shown in FIG.

In the present embodiment, the ink suction port 21 on the right side is formed near the center of the cylinder 20 and the piston head 37 moves to some extent to reduce the pressure in the suction chamber to a predetermined pressure. It is configured to communicate with the suction chamber and apply suction pressure to the nozzle portion.
As shown in the line (a), a high pressure can be instantaneously applied during ink suction. On the other hand, since the left ink suction port 22 is disposed near the end of the cylinder 20, the ink suction port 22 sucks ink as the piston head 37 moves as shown by the line (b) in FIG. . Furthermore,
The initial capacity at the start of suction of the suction chamber communicating with the ink suction port 21 on the right side is set smaller than that on the left side. Therefore, the ink suction port 21 on the right side removes the thickened ink clogged in the nozzle portion, removes bubbles in the nozzle portion, and refills (recovers) the ink with a small amount of discharged ink. Particularly, the ink suction port 22 on the left side is suitable for sucking ink accumulated in the cap member 9.

Next, in FIG. 5, reference numeral 31 denotes a cap communication hole sealing member for sealing the communication hole 9f of the right cap member 9c, and is provided on the cap carriage 10. Then, the cap communication hole sealing member 31
As shown in FIG. 16, the cap carriage 10 is pushed by the recording head carriage 3 and moves to the left to seal the communication hole 9f.

Then, as shown in FIG. 17, the station main body 4a and the right protrusion 14a are
4c to cover the black nozzle portion 3b with the right-side cap member 9c (see FIGS. 7A to 7D), and move the recording head carriage 3 to the left side to move the recording head carriage 3 to the right side. The through-hole 9f of the cap member 9c is sealed with the cap communication hole sealing member 31 (see FIG. 9E), and the ink suction pump 17a is operated in this state, thereby the black nozzle portion 3b. Foreign matter such as thickened ink can be sucked.

Further, the station main body 4a is arranged as shown in FIG.
As shown in FIG. 8, the left protrusion 14b and the engagement pin 14
c and engage the color nozzle portion 3c with the right-side cap member 9c (see FIGS. 7A to 7D).
At the same time, the recording head carriage 3 is moved to the left, and the through hole 9f of the right cap member 9c is sealed with the cap communication hole sealing member 31 (see FIG. 9E). By operating the pump 17a,
Foreign matter such as thickened ink in the color nozzle portion 3c can be sucked.

Further, the station main body 4a positions the recording head carriage 3 so that the nozzles 3b and 3c face the cap members 9c and 9d (see FIG. 17A). By operating the ink suction pump 17a, each of the nozzles 3b, 3c
The ink that has been ejected from the ink suction pump 17a is received by the cap members 9c and 9d.
Can be sucked.

Further, in FIG. 5, reference numeral 32 denotes a wiper member having a rubber blade.
a, and the cam 33 is pressed down by the cam drive transmission member 12 to set its height. In FIG. 19B, reference numerals 3j and 3k denote ink absorbers made of sponge.

As shown in FIG. 19, the station body 4a moves the wiper member 32 so that the blade tip thereof is located on the movement path of the nozzle portions 3b and 3c, and the recording head carriage. By moving the nozzle 3 from the home position to the right, the blade can be brought into contact with the tips of the nozzles 3b and 3c. In addition, the blade is cleaned by contacting the ink absorbers 3j and 3k after contacting the tip of each nozzle, so that black ink does not mix with each color ink.

Finally, in FIG. 5, reference numeral 34 denotes a pulse motor, 12 denotes a cam drive transmitting member, 35 denotes a gear train for transmitting rotation of the pulse motor 34 to the cam drive transmitting member 12, and 36 denotes a cam drive transmitting member 12. These sensors constitute the driving means.

As described above, the cam drive transmission member 12 includes a capping cam 12a for vertically moving the cap members 9c and 9d and the like, and the fixed pin 1
A gear groove for vertically moving the pump 5, a pumping cam for driving the ink suction pump 17a,
It comprises a wiping cam for moving the wiper member 32 up and down, and a cam member for the sensor 36.

Each of these cams and grooves is formed so as to move (drive) each member with respect to a predetermined rotation phase of the cam drive transmission member 12, as shown in FIG. More specifically, referring to FIG.
All members 9c, 9d, 14c, 15, 3
2 is assigned to an image forming mode in the retracted position, a cap positioning mode for raising the cap carriage 10 to the half position is assigned to 30 to 50 °, and cap members 9c and the like 9c to 70 to 120 ° are assigned.
A carriage stop mode for raising the 9d, 14c and the fixing pin 15 is assigned, and a vacuum mode for driving the pump 17a with the cap member 9c, 9d, 14c and the fixing pin 15 raised is assigned from 120 to 200 °. A vacuum mode inside the cap for driving the pump 17a with the cap members 9c, 9d, 14c and the fixing pins 15 retracted is assigned to 280 to 350 °, and a wiper member is set to 320 to 330 °. 32 is assigned. In addition, the above-mentioned vacuum mode inside the cap is used for sucking the ink ejected by the dummy jet. Also, each cap member 9c, 9d
In the vacuum mode or the dummy jet, the pulse motor 34 may be rotated a predetermined number of times in the vacuum mode or the dummy jet.

In the present embodiment, the recording head carriage 3 is set to the home position and the carriage is stopped in the non-image forming mode, and the dummy jet and the wiping mode are executed when the image forming is started. To enter image forming mode before
After the image formation, the cap positioning mode was executed, and then the carriage stop mode was set. Further, the vacuum mode was set to be executed based on a command of the user, and an experiment was performed.

As a result, in the above-described ink jet type image forming apparatus, no clogging of the nozzles 3b and 3c or poor image formation does not occur for a long period of time. It was possible to recover immediately after the occurrence.

In the ink jet type image forming apparatus of the present embodiment, the cap members 9c and 9d, the wiper member 32, the carriage position fixing member 15 and the cap communication hole sealing member 31 are formed by one pulse motor. The ink suction pump 17a is operated while the ink suction pump 17a is moved forward and backward with respect to the moving path of the recording head carriage, and ink is sucked from all the cap members 9c and 9d by one ink suction pump. Therefore, it is not necessary to provide a driving means individually for each member, and the apparatus can be extremely reduced in size.

Further, in this embodiment, the hardness of the piston ring 25 and the hardness of the sealing member 28 are each set to 2
The suction test in the vacuum mode was performed while changing the pressure to 0 to 80 Hs. As a result, as shown in FIG. 21, the piston ring 25 can obtain a sufficient suction pressure at a hardness of 30 Hs or more, and as shown in FIG. 22, the sealing member 28 has a sufficient pressure at a hardness of 30 Hs or more. A good sealing property was obtained.

[0059]

As described above, in the ink jet type image forming apparatus of the present invention, a cylinder having an internal space and two ink suction ports communicating with the internal space, and a cylinder movably disposed in the internal space. The ink suction pump is formed together with the piston, and a different suction pressure is generated in each ink suction port by moving the piston in the cylinder. Ink can be sucked at a suction characteristic corresponding to the operation.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of an inkjet type image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is an image sectional view of the recording head carriage of FIG.

FIG. 3 is an explanatory diagram of an image forming operation image of the image forming apparatus of FIG. 1;

FIG. 4 is a perspective view of the maintenance station shown in FIG. 1;

5 is an exploded perspective view of parts of the maintenance station shown in FIG.

FIG. 6 is an explanatory view of a capping operation (part 1).

FIG. 7 is an explanatory view of a capping operation (part 2).

FIG. 8 is an explanatory view of a lock operation.

FIG. 9 is a schematic explanatory diagram of an ink discharge path.

FIGS. 10A and 10B are configuration views of the ink discharge conductor (FIG. 10A is a partially cutaway perspective view, and FIG.

FIG. 11 is a front view of an ink suction pump.

FIG. 12 is an exploded view of the ink suction pump.

FIG. 13 is a view for explaining the operation of the ink suction pump (part 1).

FIG. 14 is a view for explaining the operation of the ink suction pump (part 2).

FIG. 15 shows the suction pressure of the ink suction pump.

FIG. 16 is an explanatory diagram of a sealing operation of a communication hole of a cap member.

FIG. 17 is an explanatory diagram of a vacuum operation of a right nozzle portion.

FIG. 18 is an explanatory diagram of a vacuum operation of a left nozzle unit.

FIG. 19 is an explanatory diagram of a wiping operation.

FIG. 20 is an explanatory diagram of assignment of each operation to a rotation phase of a cam drive transmission unit.

FIG. 21 is a graph showing the relationship between the hardness of a piston ring and suction pressure.

FIG. 22 is a graph showing the relationship between the hardness of the sealing member and the sealing property.

[Explanation of symbols]

1: recording medium conveying member, 3: recording head carriage, 3
b, 3c: nozzle part, 9c, 9d: cap member, 9
f: communication hole, 17: ink suction pump member, 31: cap communication hole sealing member, 32: wiper member, 15: carriage position fixing member, 10: cap carriage, 1
4: engagement member, 34: pulse motor (drive motor capable of forward / reverse rotation), 12: cam drive transmission member.

Claims (5)

[Claims] A recording head having a plurality of nozzles for ejecting ink in accordance with image information; a plurality of cap members for covering the nozzle portions; and a suction member connected to the cap member for sucking ink in the cap members. An ink-jet type image forming apparatus having an ink suction pump, wherein the ink suction pump has a cylinder having an internal space and two ink suction ports communicating with the internal space;
An ink jet type image forming apparatus, comprising: a piston movably disposed in the internal space; and generating a different suction pressure at each ink suction port by moving the piston within the cylinder. apparatus. 2. The ink suction pump according to claim 1, wherein when the cylinder is moved to one side, a high suction pressure is applied to one of the ink suction ports, and when the cylinder is moved to the other side, the other ink is sucked. 2. The image forming apparatus according to claim 1, wherein the suction pressure is applied to the mouth for a long time. 3. An ink suction port is formed near the center of the cylinder, and the other ink suction port is formed near the end of the cylinder.
The image forming apparatus of the ink jet system described in the above. 4. The image forming apparatus according to claim 1, wherein the two suction chambers formed by partitioning the inside of the cylinder with a piston have different initial capacities at the start of suction of the suction chambers. . 5. An internal space and two communicating with the internal space.
A cylinder having two ink suction ports, and a piston movably disposed in the internal space, and generating a different suction pressure at each ink suction port by moving the piston within the cylinder. An ink suction pump for an ink-jet type image forming apparatus, comprising: