JPH05301346A - Ink jet printer - Google Patents

Abstract

PURPOSE:To hermetically close the line head opposed to the platen of an ink jet printer by a simple structure. CONSTITUTION:A head covet 24 is inserted in the gap between a line head 8 and a platen 11 at least one of which is elastically held under pressure. Or, a head cover whose hermetically closed part is freely displaceable is inserted in the gap between the line head and the platen both of which are fixedly held under pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line type ink jet printer.

[0002]

2. Description of the Related Art At present, as a printer device capable of quiet and high-density printing, an ink jet printer or the like that ejects ink droplets from an orifice to fix the ink onto a printing sheet has been put into practical use.

For example, in a line type ink jet printer, a line head having a large number of orifices connected in the main scanning direction is provided, and the line is formed in an image forming section which is a recording medium which is held in position by a platen or the like and moves in the sub scanning direction. The structure is such that the ink ejection surfaces of the heads are fixedly opposed to each other.In a serial type inkjet printer, a serial head in which multiple orifices are arranged in series in the sub-scanning direction is movably supported in the main scanning direction. , A structure in which the ink ejection surfaces of the movable serial head are arranged to face each other in an image forming unit formed of a recording medium which is held in position by a platen and moved in the sub-scanning direction. In such an ink jet printer, an image is printed on a recording medium by ejecting ink droplets from the orifices of the line head and the serial head with driving power corresponding to the print image.

In such an ink jet printer, there is a concern that the ink remaining in the orifice may be hardened due to drying and may be clogged when the resting state is long. Therefore, in order to prevent such clogging of the orifice, it is necessary to attach a head cover to the line head in a rest state, as disclosed in JP-A-63-160849 and JP-A-63-1608.
No. 50 and Japanese Examined Patent Publication No. 1-30624, it is also possible to attach a head cover to a serial head in a dormant state similarly in Japanese Utility Model Publication No. 55-151548 and Japanese Utility Model Publication No. 54-5435.
It is disclosed in Japanese Patent Laid-Open No. 3-60 and Japanese Patent Laid-Open No. 56-60256.

Therefore, here, the device disclosed in Japanese Patent Laid-Open No. 63-160850 will be described as a conventional example with reference to FIGS. 9 and 10. FIG. First, in the ink jet printer 1, as illustrated in FIG. 9, a line head 2 having a large number of orifices (not shown) continuously arranged in the main scanning direction is arranged to face the platen 3, and recording is performed on the platen 3. It has a structure in which a conveyance path for the printing paper 4 which is a medium is formed. In the inkjet printer 1, as shown in FIG. 10, the platen 3 is formed of a plate 5 divided into two parts which are pivotally supported in an openable and closable manner.
In the lower part, a porous member 6 that moves in the vertical direction in association with the opening and closing is arranged.

In the ink jet printer 1 having such a structure, the porous member 6 is normally stored under the closed plate 5, as shown in FIG.
Image printing is performed by ejecting ink droplets from the orifices of the line head 2 onto the printing paper 4 conveyed on the platen 3 including these plates 5.

In the ink jet printer 1, when the above printing operation is completed, the porous member 6 rises in conjunction with the opening of the plate 5 of the platen 3 as illustrated in FIG. As illustrated in FIG. 3C, the porous member 6 is stopped in a state of being in close contact with the orifice of the line head 2. By doing so, in the inkjet printer 1, since the porous member 6 seals the inside of the orifice of the line head 2 and absorbs the remaining ink, the line head 2 of the line head 2 due to such ink fixation or dust invasion. The clogging of the orifice is prevented.

[0008]

In the line type ink jet printer 1 described above, clogging of the orifice of the line head 2 is prevented by the close contact of the movably supported porous member 6.

However, in this ink jet printer 1, since the platen 3 is formed by the plate 5 having a two-divided structure that can be opened and closed in order to arrange the porous member 6 at a position facing the orifice of the line head 2, this platen is used. Three
As a result, the existing device cannot be used, and its structure is complicated, which hinders the reduction in size and weight of the device and the productivity. Moreover, in this inkjet printer 1, the porous member 6
The platen 3 is formed by the plate 5 divided into two in order to freely retract the platen, but this is a dedicated part and it is difficult to use a general platen roller (not shown), so that the productivity is further improved. It is hindered.

For example, in an ink jet printer (not shown) disclosed in Japanese Examined Patent Publication No. 1-30624, the line head is movably supported and held at a position separated from the platen, and ink of the line head at this position is held. The discharge surface is sealed by a movable head cover. In this case, the platen can have a general structure, but a mechanism for movably supporting the line head to position and hold it between the printing position and the rest position, and a head cover for movably supporting the closed position. Since it is necessary to provide a mechanism for positioning and holding it in the separated position, such a movable mechanism becomes complicated, and the reduction in size and weight of the device and the productivity are impeded.

The present invention provides an ink jet printer having a simple structure in which the ink ejection surface of a line head can be sealed with a head cover.

[0012]

The invention according to claim 1 is
The ink ejection surface of a line head, in which a large number of orifices are continuously arranged in the main scanning direction, is arranged to face a platen via a recording medium conveyance path, and the ink ejection surface of the line head is hermetically sealed by a hermetically sealing portion. In an inkjet printer provided with a head cover, an elastic support mechanism for elastically supporting and positioning at least one of the line head and the platen relative to the other is provided, and the head cover is provided for the recording medium. A cover press-fitting mechanism for press-fitting is provided between the line head and the platen while movably supporting the same in the transport direction.

According to a second aspect of the present invention, the ink ejection surface of the line head, in which a large number of orifices are continuously arranged in the main scanning direction, is arranged to face the platen via a recording medium conveyance path, and the ink ejection of the line head is performed. In an ink jet printer provided with a head cover that hermetically seals a surface with a sealing part, at least the sealing part is formed with a structure that is elastically displaceable in a direction orthogonal to the surface,
A cover press-fitting mechanism for press-fitting the head cover is provided between the line head and the platen while supporting the head cover movably in the same direction as the recording medium transport direction.

[0014]

The driving mechanism for moving the platen to the predetermined position is required only for the head cover, and the driving mechanism for moving the line head or the platen board to the predetermined position is not necessary. It is possible to use a general component as the platen, which is simple. It is possible to obtain an inkjet printer having a structure in which the ink ejection surface of the line head can be sealed with a head cover.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention described in claim 1 will be described with reference to FIGS. First, in this inkjet printer 7, as shown in FIG.
(Not shown) are continuously provided on the ink ejection surface 9 of the line head 8 in the main scanning direction, and the platen board 1 is provided on the ink ejection surface 9 via a conveyance path of a printing paper 10 which is a recording medium.
One support surface 12 is arranged to face each other. Here, each of the platen board 11 and the line head 8 is slidably supported by slide shafts 13 and 14 in a direction of approaching and separating from each other, and is pressed toward the other by coil springs 15 and 16. The supporting protrusions 17 and 18 formed on the front and rear surfaces of the terminal end abut on the guide members 19 and 20, respectively, so that the printing paper 10 is positioned and held on the conveying path. By doing so, in the inkjet printer 7, the slide shaft 1
3, 14, the coil springs 15 and 16, the support protrusions 17 and 18, and the guide members 19 and 20,
Resilient support mechanisms 21 and 22 for slidably supporting each of the line head 8 and the platen board 11 and elastically positioning and holding them are formed.

In the ink jet printer 7, the ink ejection surface 9 of the line head 8 is sealed by the sealing portion 23.
The head cover 24 that can be freely attached and detached by means of a guide rail
It is supported slidably in the same direction as the printing paper 10 (not shown) or the like, and a rotatable pinion 26 engages with a rack 25 projecting from the rear surface of the slidable head cover 24. Therefore, the head cover 2
A cover press-fitting mechanism 27 for press-fitting 4 between the line head 8 and the platen board 11 is formed.

Here, as shown in FIG. 2, the head cover 24 of the ink jet printer 7 has triangular guide portions 29 projecting from both sides of the front surface of the cover body 28, and the front edge portion of the upper surface of the head cover 24 is protruded. A cleaning wiper 30 is mounted in the vicinity, and a recess 31 is formed in the vicinity of the trailing edge. Then, the concave portion 3 of the head cover 24
The sealing portion 23 is formed by mounting the packing 32 in the opening of the flexible tube 3 in the hole of the sealing portion 23 in which the porous body 33 is arranged.
At 4, a suction pump (not shown) is connected.

The ink jet printer 7 is
As illustrated in FIG. 3, an insertion port 36 and a discharge port 37 for the printing paper 10 are juxtaposed on the upper surface of the main body housing 35, and various operation keys 38, a display 39, and the like are provided on the front surface.

With such a configuration, in the ink jet printer 7, the line head 8 is used during a long rest period.
The ink discharge surface 9 is sealed by the sealing portion 23 of the head cover 24, and the head cover 24 is separated from the line head 8 when image printing is performed.

That is, in the ink jet printer 7, when an image is printed on the printing paper 10, as shown in FIG. 1A, the head cover 24 is retracted by the rotational drive of the pinion 26 as an initial operation, and the line head 8 is moved. And the platen board 11 are separated from each other, the line head 8 and the platen board 11 are separated from each other by the springs 15 and 1.
6 is pressed by the supporting projections 17 and 18 and the guide member 19,
The contact with the sheet 20 positions and holds the print sheet 10 on the transport path. Therefore, in this state, the printing paper 10 inserted in the insertion opening 36 of the main body housing 35 is
Since the line head 8 discharges ink droplets onto the printing paper 10 that moves in the sub-scanning direction on the support surface 12, the dot matrix image printing is performed.

In the ink jet printer 7, the ink ejection surface 9 of the line head 8 is covered by the head cover 2.
In the case of sealing with the sealing unit 23 of No. 4, it is confirmed as an initial operation that the printing paper 10 does not exist between the line head 8 and the platen board 11, and after this confirmation, the pinion 26
The head cover 24 is moved forward by the rotational driving of, and is press-fitted between the line head 8 and the platen board 11 from the sharp guide portion 29. By doing this,
As illustrated in (b), the line head 8 and the platen board 11 elastically held by the pressing force of the springs 15 and 16 are used.
Means that the head cover 24 slides in the vertical direction as the head cover 24 is press-fitted, and in this process, the cleaning wiper 30 of the head cover 24 scrapes and cleans the ink ejection surface 9 of the line head 8. Then, at the position where the sealing portion 23 of the head cover 24 which moves in this manner comes into close contact with the ink ejection surface 9 of the line head 8, the pinion 2
When the drive of 6 is stopped, the cleaning wiper 3
The ink ejection surface 9 of the line head 8 that has been cleaned at 0 is sealed from the outside air by the sealing portion 23 of the head cover 24.

By doing so, the ink jet printer 7 can be prevented from being dried and clogging due to the ink in the orifice of the line head 8 being closed for a long period of time by sealing the head cover 24. It can contribute to the improvement of image quality and reliability. Moreover, in this inkjet printer 7, the elastic support mechanisms 21, 2
Line head 8 and platen board 1 held by 2
Since the head cover 24 that slides between the head cover 24 and 1 is press-fitted, a drive mechanism for moving the line cover 8 and the platen board 11 to a predetermined position is required only for the head cover 24. Since it is unnecessary, the structure is simple, and it can contribute to reduction in size and weight and improvement in productivity. Further, in the inkjet printer 7, general parts can be used as the platen board 11, and a platen roller having a function of conveying the printing paper 10 can also be used as such a part, which further improves productivity. Can contribute.

In the ink jet printer 7, the ink inside the line head 8 is driven by driving the line head 8 and the suction pump while the ink discharge surface 9 is sealed by the sealing portion 23 of the head cover 24 as described above. At the same time, dust in the orifice can be removed. Further, in this inkjet printer 7, the ink discharged into the head cover 24 as described above is adapted to be sucked from the flexible tube 34 by the suction pump, but a part of the ink is stored in the sealed portion 23 of the head cover 24. The ink is absorbed by the porous body 33 to prevent the ink in the line head 8 from drying. Further, in the inkjet printer 7, the cleaning by the cleaning wiper 30 is compulsorily performed even when the head cover 24 that seals the line head 8 separates to start the image printing, so that the line head can be used even after a long break. The printing operation of No. 8 is performed well.

In the ink jet printer 7 of this embodiment, both the line head 8 and the platen board 11 are elastically held by the elastic support mechanisms 21 and 22, but the present invention is limited to the above structure. However, an inkjet printer (not shown) that elastically holds only one of the line head 8 and the platen board 11 can be implemented.

Next, an embodiment of the invention described in claim 2 will be described with reference to FIGS. First, in this ink jet printer 40, as illustrated in FIG. 4, a large number of orifices (not shown) are connected to the ink ejection surface 9 of the line head 8 in the main scanning direction. An outer peripheral surface 42 of a platen roller 41, which is rotatable via a conveyance path of the printing paper 10, is arranged oppositely.

Then, the ink jet printer 40
Then, as illustrated in FIG. 5 and FIG. 5, the line head 8
A head cover 44 that seals the ink ejection surface 9 of the above with a sealing portion 43 so as to be freely separable is supported slidably in substantially the same direction as the printing paper 10 by wires 45 connected to the front and rear surfaces. A cover press-fitting mechanism 48 for press-fitting the head cover 44 between the line head 8 and the platen roller 41 by being wound around rotatable pulleys 46 and 47 positioned in front of and behind the head cover 44.
Are formed.

Here, the ink jet printer 40
As shown in FIG. 6, the head cover 44 of FIG. 6 has a cleaning wiper 50 integrally projecting near the front edge of the upper surface of the cover main body 49, and the sealing portion 43 with the recess 51 near the rear edge. And the entire cover body 49 is made of butyl rubber or EPDM (Ethylene Pro).
The sealing portion 43 is elastically displaceable in the direction orthogonal to the surface by being formed of an elastic material such as pylene Diene Methylene Rubber.

With this structure, in the ink jet printer 40, the ink ejection surface 9 of the line head 8 is sealed by the sealing portion 43 of the head cover 44 during a long period of non-operation, and image printing is performed. In this case, the head cover 44 is separated from the line head 8.

That is, the ink jet printer 40
Then, when an image is printed on the printing paper 10, as shown in FIG.
As illustrated in FIG. 6, the head cover 44 is retracted by the rotational drive of the pulleys 46 and 47 as the initial operation, and the line head 8 is moved.
And the platen roller 41 are separated from each other, the dot matrix image printing is performed by the line head 8 ejecting ink droplets onto the printing paper 10 conveyed on the outer peripheral surface 42 of the platen roller 41 in this state.

Then, the ink jet printer 40
Then, when the ink ejection surface 9 of the line head 8 is sealed by the sealing portion 43 of the head cover 44, the printing paper 10 is provided between the line head 8 and the platen roller 41 as an initial operation.
Is confirmed to be absent, and after this confirmation, Pinion 2
The head cover 44 moves forward by the rotational drive of 6, and is press-fitted between the line head 8 and the platen roller 41. By doing so, the head cover 44 made of an elastic material is provided in the gap between the line head 8 fixedly provided and the platen roller 41, as illustrated in FIG.
Is slightly deformed and press-fitted, and in this process, the cleaning wiper 30 of the head cover 44 scrapes and cleans the ink ejection surface 9 of the line head 8. The head cover 44 that moves in this way
The drive of the pulleys 46 and 47 is stopped at a position where the closed portion 43 of the line head 8 is in close contact with the ink ejection surface 9 of the line head 8, so that the ink ejection surface 9 of the line head 8 that is cleaned by the cleaning wiper 30 becomes the head cover 44. Sealing part 43
Then it will be sealed from the outside air. In the inkjet printer 40, the head cover 4 as described above is used.
The platen roller 41 is also rotationally driven when the press-fitting of No. 4 is performed.

By doing so, in the ink jet printer 40, by sealing the head cover 24, it is possible to prevent the ink in the orifice of the line head 8 from drying and clogging during a long period of rest, It can contribute to the improvement of image quality and reliability. Moreover, in this inkjet printer 40, since the head cover 44 that slides between the line head 8 and the platen roller 41 that are fixedly held is press-fitted, the drive mechanism that moves the head cover 44 to a predetermined position is the head cover 44. Only necessary for line head 8 and platen roller 41
Since a drive mechanism for moving the tongue to a predetermined position is unnecessary, the structure is simple, and it is possible to contribute to reduction in size and weight and improvement in productivity. Further, in the inkjet printer 40, a general component can be used as the platen roller 41, and a platen roller having a function of transporting the printing paper 10 can also be used as such a component.

In this embodiment, the ink jet printer 40 in which the head cover 44 is used to seal the line head 8 is illustrated, but the present invention is not limited to the above structure, and as shown in FIG. It is also possible to implement an inkjet printer 53 that sucks and removes dust in the orifice of the line head 8 by connecting the suction pump 52 to the sealing portion 43 with the flexible tube 34. Further, in the ink jet printer 40 of the present embodiment, the head cover 44 is entirely made of an elastic material, but as shown in FIG. 8, the rigid plate 5 is used.
It is also possible to implement a head cover 57, etc., in which the sealing portion 56 is displaceable in the direction orthogonal to the surface with the structure in which the elastic plate 55 is attached on the 4 and by doing so, unnecessary deformation of the head cover 57 is reduced and it is durable. It is possible to improve the property.

[0033]

According to the first aspect of the present invention, the ink ejection surface of the line head in which a large number of orifices are continuously arranged in the main scanning direction is arranged to face the platen via the recording medium conveyance path.
In an inkjet printer provided with a head cover that seals the ink discharge surface of a line head with a sealing portion so as to be freely separable, at least one of the line head and the platen is movably supported with respect to the other and elastically positioned and held. Drive to move to a predetermined position by providing a resilient support mechanism and a cover press-fitting mechanism that press-fits between the line head and the platen by supporting the head cover movably in the same direction as the recording medium conveyance direction. The mechanism is required only for the head cover and does not require a drive mechanism for moving the line head or platen board to a predetermined position, and it is possible to use general parts as a platen, so the ink ejection surface of the line head can be used with a simple structure. It has effects such as being able to obtain an inkjet printer that can be sealed with a head cover. .

According to a second aspect of the present invention, the ink ejection surface of the line head, in which a large number of orifices are continuously arranged in the main scanning direction, is arranged to face the platen via the recording medium conveyance path, and the ink ejection surface of the line head is arranged. In an ink-jet printer provided with a head cover that can be attached and detached by a hermetically-sealing portion, at least the hermetically-sealing portion is elastically displaceable in a direction orthogonal to the surface, and the head cover is formed, and the head cover is formed in a recording medium conveying direction. By providing a cover press-fitting mechanism for press-fitting between the line head and the platen supported movably in substantially the same direction, the drive mechanism for moving to a predetermined position is necessary only for the head cover and the line head and the platen board are predetermined. It does not require a drive mechanism to move it to a position, and it is possible to use common parts as a platen, so a simple structure is possible. In an ink ejection surface of the line head in which an effect of such can be obtained an ink jet printer capable of sealing in the head cover.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the invention described in claim 1.

FIG. 2 is a perspective view showing an enlarged head cover.

FIG. 3 is a front view showing the overall appearance.

FIG. 4 is a side view showing an embodiment of the invention described in claim 2.

FIG. 5 is a plan view.

FIG. 6 is a perspective view showing an enlarged head cover.

FIG. 7 is a side view showing a modified example.

FIG. 8 is a vertical cross-sectional side view showing a modified example of the head cover.

FIG. 9 is a perspective view showing a conventional example.

FIG. 10 is a side view showing an enlarged main part.

[Explanation of symbols]

 7, 40, 53 Inkjet printer 8 Line head 9 Ink ejection surface 10 Recording medium 11, 41 Platen 21, 22 Elastic support mechanism 23, 43, 56 Sealing part 24, 44, 57 Head cover 27, 48 Cover press-fitting mechanism

Claims (2)

[Claims] 1. An ink ejection surface of a line head, in which a large number of orifices are continuously arranged in the main scanning direction, is arranged to face a platen via a conveyance path of a recording medium, and the ink ejection surface of the line head is in contact with a sealed portion. In an inkjet printer provided with a head cover that is detachably sealed, an elastic support mechanism that elastically positions and holds at least one of the line head and the platen with respect to the other is provided, and the head cover is provided. And a cover press-fitting mechanism that press-fits between the line head and the platen to movably support the recording medium in a direction substantially the same as the conveying direction of the recording medium. 2. An ink ejection surface of a line head, in which a large number of orifices are continuously arranged in the main scanning direction, is arranged opposite to a platen via a recording medium conveyance path, and the ink ejection surface of the line head is in contact with a sealed portion. In an inkjet printer provided with a head cover that is detachably sealed, at least the sealed portion is elastically displaceable in a direction perpendicular to the surface, and the head cover is formed so that the head cover is substantially parallel to the recording medium transport direction. An ink jet printer characterized in that a cover press-fitting mechanism for press-fitting is provided between the line head and the platen so as to be movably supported in the same direction.