JP2002103638A - Line head cleaning device of ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a line head cleaning device capable of cleaning a line head in the middle of printing easily by a simple mechanism in an ink jet printer which uses the line head having ink nozzles arranged in a line. SOLUTION: A cleaning means 30 for the line head 11 where ink nozzles for discharging different color inks are arranged includes a shifting means 20 for rotating the line head 11 by a rotary shaft 24 on a plane parallel to a recording medium at a recording region A, thereby advancing and retracting the line head 11 between the recording region A including a recording position and a non image region B sideways in a transfer direction of the recording medium, and the cleaning means 30 set to the non image region B for cleaning a nozzle face of the line head 11 by moving up and down in a direction 35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer capable of performing high-speed printing by using a line head in which ink nozzles are arranged in a line, and to a cleaning device for a nozzle surface of the line head.

[0002]

2. Description of the Related Art An ink jet printer has a simpler structure for forming an image than an electrophotographic printer or the like. In particular, if a head is configured to eject ink of each color, color printing is possible, and digital printing is possible. With the spread of cameras and the like, it is rapidly spreading mainly for home use. However, many of these inkjet printers scan the head in a direction perpendicular to the direction in which the recording paper is conveyed, and there is a major problem in that the printing speed is slow.

For this reason, the recording paper is transported continuously by using a line head having ink nozzles arranged in a line and transporting the recording paper at a transport speed corresponding to the ink droplet ejection speed and the ink droplet volume. Some ink jet printers that can perform high-speed printing have also been put to practical use.

This type of ink jet printer is liable to cause deterioration of print quality due to clogging of the ink nozzles due to the deteriorated ink and intrusion of dust into the ink nozzles, and it is necessary to clean the line head. A cleaning device disclosed in Japanese Patent Application Laid-Open No. 7-246711 as a conventional technique raises a line head from a platen holding a recording sheet, moves the line head in parallel with the platen, and introduces the line head into a cleaning unit to clean the surface of the line head. Cleaning is performed by scanning the cleaning member. Further, since the cleaning means is on the paper conveyed in the print conveyance path, when ink leakage or the like occurs, the print quality is reduced. Also,
In another prior art, the line head is moved around its axis by 9 mm.
It is configured to be rotated 0 degrees or 180 degrees and introduced into the cleaning unit. That is, at 90 degrees, the cleaning means is provided on the side of the line head, and at 180 degrees, the cleaning means is provided above the line head.

[0005]

According to the above-mentioned method, even if the necessity of cleaning occurs during the printing of one sheet, if the cleaning is performed, the recording paper will be damaged, and the cleaning cannot be performed during the printing. Further, even when cleaning is performed between recording sheets, the number of components to be operated for cleaning is large, which not only complicates the driving but also makes it difficult to make the distance between the head and the recording sheet necessary for print quality constant. Becomes In the above-described inkjet printer that scans the head, it is necessary to clean the head in the same manner.However, the head to be scanned is moved to a home position outside the recording area, and cleaning is appropriately performed by a cleaning unit provided at the home position. Therefore, there is little problem in cleaning such as damage to the recording paper as described above.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a line head cleaning in an ink jet printer using a line head in which ink nozzles are arranged in a line so that the line head can be easily cleaned during printing with a simple mechanism. It is to provide a device.

[0007]

According to the present invention, there is provided a line head cleaning apparatus for an ink jet printer having a line head in which ink nozzles for ejecting inks of different colors are arranged. It is rotated on a plane parallel to the recording medium in the recording area to advance and
There is provided a configuration including a displacement unit for retreating and a cleaning unit disposed in the non-image area and cleaning the nozzle surface of the line head. The cleaning device of the ink jet printer using the line head capable of high-speed printing of the present invention, for cleaning the line head against a change in the composition of ink or suction of dust, arranges a cleaning unit in a non-image area, The line head is rotated by a displacement unit on a plane parallel to the recording paper in the recording area, that is, on a plane parallel to the platen, and is introduced into the cleaning unit. Therefore,
Even if cleaning is completed and the line head is returned to the recording area, there is no deviation in the distance between the line head and the recording paper, and cleaning can be performed at any timing as needed even during printing on one recording paper. And good print quality can be obtained. In addition, it can be realized with a simple configuration of simply rotating in parallel.

[0008] The cleaning device of the present invention includes the following line head displacement means. That is, a rotating shaft erected on one side in the recording medium conveyance direction, a first bracket supporting one end of the line head on the rotating shaft, and a circular arc formed equidistantly about the rotating shaft. A guide member,
A second bracket that supports the other end of the line head and is slidably disposed on the guide member, and abuts on the other end of the line head when the line head advances to the recording position; A contact piece for positioning the head at the recording position;
And a driving means for driving the rotating shaft to rotate. With this configuration, the cleaning device of the present invention is configured to rotate the line head on a plane parallel to the recording paper in the recording area to introduce the line head into the cleaning unit, and to return the line head after cleaning to the recording area. In this case, there is no deviation in the distance of the line head with respect to the recording paper, and the line head can be realized with a simple configuration of only rotation.

The line head according to the present invention has a length of 2 mm.
The cleaning device has a configuration in which the displacement means of the line head includes a rotating shaft erected on both sides in the recording medium transport direction, and a second shaft that supports one end of the divided line head on the rotating shaft. A bracket, an arc-shaped guide member formed equidistantly around each of the rotation axes, and a second supporting each of the other ends of the two divided line heads so as to be slidable on the guide member. And a contact piece that contacts the other end of the line head when the line head advances to the recording position and positions the line head at the recording position, and a driving unit that rotationally drives the rotation shaft. It is composed.

The nozzles of the line head according to the present invention are arranged at right angles to the recording medium transport direction for each color and at intervals in the transport direction for each color. The arrangement in which the directions are arranged is such that the upstream side in the transport direction has a lighter hue than the downstream side. The line head having this configuration can reduce the influence on ink ejected after ink ejected earlier.

In the line head according to the present invention, the home position is located above the cleaning means, and the displacement means positions the line head at the home position during a non-recording operation and advances to the recording area when a recording is requested. The cleaning means includes a cleaning blade for wiping the surface of the line head, a suction cap for sucking degraded ink and dust from the ink nozzle in close contact with the surface of the line head, and a pump for applying a negative pressure to the suction cap. And a drive means for applying one of a cleaning blade and a suction cap to the surface of the line head retracted to the home position. In this configuration, the cleaning of the line head is performed by wiping ink and dust attached to the surface of the line head with a cleaning blade and sucking out the degraded ink and dust in the ink nozzles with a suction cap and a pump. During the non-printing operation, even after the printing is completed, the line head is located on the cleaning means at the home position, and the ink nozzle is covered with the suction cap, so that the evaporation of the ink can be prevented.

[0012]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is an external view of an ink jet printer provided with a cleaning device according to the present invention, and FIG. 2 is a schematic diagram for explaining a printing process. The inkjet printer (device) 2 has a recording unit therein.
A printing (recording) operation in the device 2 will be described. The recording paper P is placed on a paper feed tray 3 connected to the apparatus or a paper feed cassette 4 provided at a lower part of the apparatus. Then, when a printing request based on image information from a computer or the like (not shown) is made to the apparatus, the pickup rollers 5 and 6 convey the recording paper one by one to a paper feeding process. The recording paper transported by the pickup rollers 5 and 6 is guided to paper transport paths 7 and 8 and is further recorded via PS rollers 9 and 10 that adjust the leading edge of the image information and the leading edge of the paper based on the image information. Reach the area. In the recording area,
As shown in FIGS. 3 and 4, an ink head 12 for perforating the ink discharge nozzles, a line head 11 for mounting the ink tank 13, and a platen 14 opposed thereto are arranged.

Next, the line head 11 will be described. ... See FIGS. 3 and 4 FIG. 3 is a side view of the line head 11, and FIG. 4 is a bottom view thereof. The ink head 12 is a direction orthogonal to the transport direction 15 of the recording paper (recording medium) for each color,
In addition, they are arranged side by side in the transport direction 15 for each color with an interval therebetween. The nozzle of each color is yellow 11Y, magenta 1
1M, cyan 11C, and black 11B. The ink nozzles of each color are arranged such that the upstream side in the transport direction 15 of the recording medium P has a lighter hue than the downstream side. That is, from the upstream side to the downstream side, yellow 11Y,
Magenta 11M, cyan 11C, and black 11B are arranged in this order. As a result, the influence on ink ejected after ink ejected earlier is reduced.

The ink nozzles 11Y, 11M, 11C, 1
1B are arranged at a pitch corresponding to a desired resolution. In the embodiment shown in FIG. 4, the ink nozzles 11Y, 11M, 11C, 11C of the respective colors are arranged in the orthogonal direction in order to narrow the pitch in the direction orthogonal to the recording medium transport direction 15.
B is arranged in a staggered manner. This ink nozzle 11
Y, 11M, 11C, and 11B are provided at least over the maximum width of paper that can be transported by the apparatus, and ink is ejected from necessary nozzles in accordance with image information.
Recorded above. The transport speed of the recording paper P is determined by the printing resolution of the apparatus, that is, the capacity of the ink droplets and the cycle of the ink ejection timing. The transport of the recording paper is always performed without stopping, and high-speed printing is possible. It has become. The recording paper P on which the image information is written in this manner is
The paper is discharged onto the paper discharge tray 18 via the paper discharge rollers 16 and 17 and is provided to the user as printed matter.

In the present invention, the cleaning device is provided on the side of transport of the recording paper P in an area that is a non-image area even when a recording paper of the maximum size that can be printed is used. Hereinafter, an embodiment of the cleaning device of the present invention will be described.

Embodiment 1 A cleaning device for a line head of an ink jet printer according to the present invention will be described with reference to FIGS. The cleaning device 1 includes a displacement device 20 and a cleaning unit 30.

The displacement device 20 moves the recording paper P in the transport direction 1
5, a first bracket 25 supporting one end 11α of the line head 11 on the rotating shaft 24, and an equal distance (the length of the line head 11) about the rotating shaft 24. ), A second bracket 27 supporting the other end 11β of the line head 11 slidably disposed on the guide member 26, and a line head. At the time of advance to the recording position of 11,
A contact piece 28 that contacts the other end 11β of the head and positions the line head 11 at the recording position, and a drive unit (not shown) that includes a motor, a drive belt, and the like, and that drives the rotating shaft 24 to rotate reversibly. You.

With the displacement device 20 configured as described above, the line head 11 is rotated on a plane parallel to the recording paper 29P in the recording area around the rotation shaft 24, that is, in parallel with the platen 14, to perform recording. It is possible to retreat from the area A to the non-image area B on the side in the transport direction 15 and to advance from the non-image area B to the recording area A.

In the non-image area B, a cleaning unit 30 for cleaning the line head 11 is arranged. The line head 11 is set with its home position immediately above the cleaning unit 30 and the displacement device 20.
5, during the non-printing operation, it is retracted to the position shown by the broken line in FIG. 5, that is, the home position on the non-image area B, and when printing is requested, it is advanced to the recording area A as shown by the solid line.

Next, the structure and operation of the cleaning unit 30 will be described. FIG. 7 is an explanatory sectional view of the cleaning unit. The cleaning unit 30 includes a cleaning blade 31 for wiping the surface of the line head 11.
And the ink nozzle 1 in close contact with the surface of the line head 11.
1Y, 11M, 11C, and 11B, a suction cap 32 for sucking degraded ink and dust, a pump PU (not shown) for applying a negative pressure to the suction cap 32, and a cleaning blade on the surface of the line head retracted to the home position. A scanning unit (not shown) for operating the suction unit 31 and a lifting / lowering unit (member) 37 for operating the suction cap 32 are provided.

The cleaning blade 31 is mounted on a holding plate 33 and has a height H of about 7 to 10 mm. The holding plate 33 is slidably displaceable on a guide member extending in, for example, the recording paper transport direction 15, that is, extending parallel to the line head 11 at the home position. Then, by being driven by a drive belt or the like, as shown by the arrow 34 in FIG. 7, the arrow 3 from the start end (the cleaning blade 31 shown by the solid line) to the end (the cleaning blade 31 shown by the broken line)
It reciprocates as shown by 4. Thus, the cleaning blade 31 wipes off ink and dust adhering to the surface of the line head 11.

The suction cap 32 is guided by an elevating member 37 extending vertically, for example, and is displaced up and down as indicated by an arrow 35 by a drive belt or the like. At the raised position, the suction cap 32 is in close contact with the line head 11. When the pump PU is driven, the deteriorated ink and dust in the ink nozzles are sucked out. The solidified ink is also sucked out at the start of use after a long stop. Further, during the non-printing operation, the suction cap 32 is in close contact with the line head 11 and the ink nozzle 11
Y, 11M, 11C and 11B are covered to prevent evaporation of ink.

The operation of each of these devices is controlled by control means (not shown). FIG. 8 is a flowchart for controlling the operation of the inkjet printer 2 configured as described above. When the power is turned on, the process proceeds to step S1, where it is determined whether the line head 11 is at the home position on the cleaning unit 30 or not. If the line head 11 is not at the home position when the ink tank 12 is replaced or the ink jet printer 2 is conveyed, the displacement device 20 is driven to return the line head 11 to the home position at step S2. It returns to step S1. When the line head 11 is at the home position, the process returns to step S3.

In step S3, the cleaning unit 30 is driven to clean the line head 11 as described above, and in step S4, a standby state for a print request is made. When a print request is issued in step S5, the displacement device 20 is driven in step S6 to
1 is advanced to the recording area A. In step S7, printing of one line is performed, and in step S8, it is determined whether there is a next line to be printed. If there is a next line for printing, the process proceeds to step S9. In step S9, it is determined whether or not it is necessary to perform cleaning due to clogging of the ink nozzles 11Y, 11M, 11C, and 11B. If not, the flow returns to step S7 to continue printing on the next line. Done.

In this way, if the necessity of cleaning occurs during printing, the necessity of cleaning is determined in step S9, and the process proceeds to step S10. In step S10, the displacement device 20 is driven to return the line head 11 to the home position. After cleaning is performed in step S11, the displacement device 20 is driven in step S12 to advance the line head 11 to the recording area A again. After that, the process returns to the printing process in step S7. The step S
In step 8, when it is determined that there is no next line to be printed, that is, when the printing process on one sheet is completed, the process proceeds to step S13, in which the displacement device 20 is driven to return the line head 11 to the home position B. At step 14, cleaning is performed. In this way, cleaning is performed at least for each sheet, and good print quality can be obtained.

When cleaning is completed in step S14, it is determined in step S15 whether or not there is a next page to be printed. If not, the pump PU is stopped in step S16, and the surface of the line head 11 is removed from the suction cap. The process is terminated while being covered with 32. If there is the next printing, the displacement device 20 is driven in step S17, and the line head 11 advances to the recording area A again. Then, the process returns to the printing process in step S7. The integrated value of the number of ink ejections may be used to determine whether or not cleaning is necessary in step S9.

To perform the cleaning as described above, the cleaning unit 30 is disposed in the non-image area B, and the line head 11 is moved by the displacement device 20 on a plane parallel to the recording paper 29P in the recording area A, that is, in parallel with the platen 14. To the cleaning unit 30, and even if the cleaning is completed and the line head 11 is returned to the recording area A, the recording paper 29 </ b> P
There is no deviation in the distance of the head 11 from the recording paper 29P, and cleaning can be performed at any timing as needed even during printing on one sheet of recording paper 29P, and good printing quality can be obtained. Further, it can be realized with a simple configuration in which the line head 11 is simply rotated in parallel, and good print quality can be guaranteed for a long time without deterioration in accuracy.

Embodiment 2 Another embodiment of the present invention will be described with reference to FIGS. FIG. 9 is an explanatory plan view of the operation of the cleaning device 41, and FIG. 10 is a side view thereof. The cleaning device 41 shown in this embodiment is configured by dividing a line head into two in the longitudinal direction.

The two divided line heads are divided into a first line head 11a and a second line head 11b.
And A first one disposed downstream of the recording medium P in the transport direction.
And the second line head 11b disposed on the upstream side. Parts corresponding to the structure of the cleaning device shown in the first embodiment are denoted by the same reference numerals with suffixes a and b, and the description thereof will be omitted. The second line head 11b on the upstream side in the recording medium conveyance direction 15 has one end rotatably supported by the rotation shaft 24b, and the other end 110β abuts on the contact piece 28 and is positioned. First line head 11 on the downstream side in transport direction 15
a is rotatably supported at one end by a rotation shaft 24a;
10α is positioned in contact with the other end 110β of the second line head 11b.

Then, the first line head 11a
Of the recording area A and the home position (non-recording area B) on the cleaning device. Similarly, the second line head 11b is guided by the second guide member 26b and retracts and advances between the recording area A and the home position (non-recording area B) on the cleaning device.

With this configuration, the first line head 1
1a and the second line head 11b can shorten the moving distance from the recording area A to the cleaning units 30a and 30b, that is, the home position (non-recording area B), and can move quickly. That is, when the necessity of cleaning occurs, the time required for cleaning can be shortened.

[0032]

As described above, according to the present invention, the line head is moved between the recording area and the non-image area (non-recording area).
With a simple configuration of rotating the recording head in parallel with the recording surface of the recording medium, highly accurate displacement of the line head can be achieved, and cleaning of the line head can be easily performed even during printing. In addition, the line head is located above the cleaning device in the non-image area, so that reliable cleaning is performed. During non-printing, the line head surface is covered with the cleaning device, and evaporation of ink can be prevented.

[Brief description of the drawings]

FIG. 1 is an external view of an inkjet printer provided with a cleaning device according to the present invention.

FIG. 2 is a diagram illustrating the configuration of an ink jet printer.

FIG. 3 is a side view of the line head of the inkjet printer.

FIG. 4 is a bottom view of the line head of the inkjet printer.

FIG. 5 is a plan view illustrating the operation of the cleaning device according to the present invention.

FIG. 6 is a side view of the cleaning device.

FIG. 7 is a diagram illustrating the operation of the cleaning device.

FIG. 8 is a control flowchart of the cleaning device.

FIG. 9 is a plan view illustrating the operation of the cleaning device according to the second embodiment of the present invention.

FIG. 10 is a side view of the cleaning device according to the second embodiment.

[Explanation of symbols]

 1, 41 Cleaning device 2 Ink jet printer 11 Line head 12 Ink head 13 Ink tank 14 Platen 15 Recording medium conveyance direction 20 Displacement device 24 Rotary shaft 25 First bracket 26 Guide member 27 Second bracket 28 Contact piece 30 Cleaning Unit 31 Cleaning blade 33 Holding plate

Claims (5)

[Claims] In a head cleaning apparatus of an ink jet printer having a recording head in which ink nozzles for discharging ink are arranged, the recording head moves a nozzle for discharging ink of a different color in a transport direction of a recording medium for each color. Forming a line head arranged orthogonal to the, the cleaning device, the line head between the recording area including the recording position and the non-image area on the side of the recording medium transport direction, the recording medium in the recording area A line head cleaning device for an inkjet printer, comprising: a displacement unit that rotates on a parallel plane to advance and retreat, and a cleaning unit that is disposed in the non-image area and cleans a nozzle surface of the line head. 2. The apparatus according to claim 1, wherein the displacement means of the line head includes a rotating shaft erected on one side in the recording medium transport direction, a first bracket supporting one end of the line head on the rotating shaft, and the rotating shaft. An arcuate guide member formed equidistantly around the center, a second bracket supporting the other end of the line head, and slidably disposed on the guide member;
When the line head advances to the recording position, the line head includes an abutting piece that contacts the other end of the line head and positions the line head at the recording position, and a driving unit that rotationally drives the rotation shaft. 2. The line head cleaning device for an ink jet printer according to claim 1, wherein: 3. The line head has a length of 2 mm.
The line head displacement means is divided into a rotating shaft erected on both sides in the recording medium transport direction, and a first bracket for supporting one end of the line head divided into two by the rotating shaft. , Around each of the rotation axes,
Arc-shaped guide members formed at equal distances, second brackets respectively supporting the other ends of the two divided line heads slidably on the guide members, and the recording positions of the line heads And a contact piece that abuts on the other end of the line head when positioning the line head at the recording position, and a driving unit that rotationally drives the rotating shaft. The line head cleaning device for an ink jet printer according to claim 1, wherein 4. The nozzles of the line head are arranged so as to be spaced apart from each other in the transport direction between the respective colors, and the arrangement of the colors in the recording medium transport direction is such that the upstream side in the transport direction is the downstream side. The line head cleaning device for an ink jet printer according to any one of claims 1 to 3, wherein the color head has a lighter hue. 5. The line head has its home position above the cleaning means, and the displacement means causes the line head to retreat to the home position during a non-recording operation, and moves the line head to the recording area when a recording is requested. And a cleaning blade for wiping the surface of the line head, a suction cap for sucking degraded ink and dust from the ink nozzle in close contact with the surface of the line head, and a suction cap for A pump for applying a negative pressure to the nozzle surface of the line head retracted to the home position,
5. The line head cleaning device for an ink jet printer according to claim 1, further comprising: a driving unit that operates any one of the cleaning blade and the suction cap. 6.