JP3783602B2 - RECORDING MEDIUM CONVEYING DEVICE AND RECORDING DEVICE HAVING RECORDING MEDIUM CONVEYING DEVICE - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording medium conveying apparatus and a recording apparatus including the recording medium conveying apparatus, and more particularly to a technique for sucking and holding a recording medium in a recording unit of the recording apparatus and smoothly ejecting the recording medium after completion of printing.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, for example, in an ink jet printer or an ink jet plotter, after a recording medium is fed to a recording unit by a paper feed roller, it is ejected while being pressed by a paper discharge roller (drive roller) and a spur roller as its driven roller. There is something. FIGS. 6A, 6B, and 6C are diagrams illustrating only a recording unit and a main part of a recording medium conveyance device in such an inkjet printer.
[0003]
That is, in such an ink jet printer or the like, as shown in FIG. 6A, after the recording medium 1 is fed into the recording unit 3 by the paper feed roller 2 (and its driven roller 2a), the paper discharge roller (drive roller) ) 4 and the spur roller 5 as the driven roller are discharged while being pressed. In this case, the pressing force of the spur roller 5 is set to such an extent that the recording medium 1 is not scratched (spur mark).
[0004]
[Problems to be solved by the invention]
However, in an inkjet printer including a recording medium conveyance device as shown in FIG. 6A, for example, when an image in which a large number of ink particles are ejected is recorded on the recording medium 1, such as a solid image. The recording medium 1 sometimes absorbs a large amount of ink, and as shown in FIG. 6B, a so-called cockling that swells toward the recording head 6 may occur.
[0005]
When this cockling occurs, the interval between the recording medium 1 and the recording head 6 becomes narrow and the flying distance of the ink particles varies, resulting in recording unevenness, or the recording medium 1 comes into contact with the recording head 6 and becomes dirty. There was a bug. Also in the recording medium conveying apparatus shown in FIG. 6A, if the span between the paper feed roller 2 and the paper discharge roller 4 is relatively short, the above-described problem is caused by holding the cockling within an allowable range. It is also possible to prevent as much as possible.
[0006]
However, in the near future, in order to further increase the recording speed, it is necessary to increase the number of nozzles for each color nozzle array, or arrange a plurality of color nozzle arrays in the conveyance direction of the recording medium. In these cases, as shown in FIG. 6C, the dimension of the recording head becomes longer in the conveyance direction of the recording medium. As the recording head 10 becomes longer, the span between the paper feed roller 2 and the paper discharge roller 4 also becomes longer. Therefore, the paper feed roller 2 (and its driven roller 2a) and the paper discharge roller 4 (and a spur roller as its driven roller). In the configuration in which the paper is sandwiched and transported and ejected in step 5), this cockling cannot be prevented at all and exceeds the allowable range. Depending on the type of the ink jet printer having such a large head length, it is sandwiched between the two sets of rollers. There may be a situation in which the structure for transporting and discharging is not realized.
[0007]
Such cockling is relatively small when dedicated paper such as an ink jet printer is used as a recording medium, and large when plain paper is used. For this reason, normally, in designing an inkjet printer or the like, a paper gap [the distance between the recording medium 1 and the recording head 6 in FIG. A] is increased. However, if the paper gap is large in this way, even if special paper that is not necessary is used, the ink particles ejected from the nozzles of the recording head will bend and the deviation of the landing point will be increased accordingly. , Which may hinder the improvement of print quality.
[0008]
Further, when the recording medium 1 is lifted by cockling, the floating recording medium 1 is pressed against the spur roller 5 as shown by an arrow B in FIG. As shown, a spur mark by the spur roller 5 is attached. This spur trace is particularly noticeable on plain paper with a large cockling, and is a cause of lowering the print quality.
[0009]
On the other hand, in recent years, there are various types in which a suction box having a hollow box shape is mainly provided on the conveyance surface of a recording medium, and the recording medium is sucked by a suction pump or the like through a plurality of suction (through) holes provided in the suction part. It has been proposed (see Japanese Patent Laid-Open Nos. 63-303781 and 3-270). Among these, as a means for eliminating the above-described cockling, there is proposed that a recording medium is sucked or sucked onto a platen or the like through the suction holes.
[0010]
However, in any case, only a through hole is opened in the hollow box-like suction part and suction is performed, and it is difficult to prevent the above-described cockling over the entire surface of the recording medium in the recording part. In addition, as a result of the portion of the recording medium coming out from the recording portion being lifted and being pressed against the spur roller 5 as shown by the arrow B in FIG. 6B, the recording medium 1 has a spur mark. It cannot be prevented.
[0011]
Further, in the conventional example described in the above publication, since the through-hole is opened in the hollow box-like suction part and suction is performed, if the suction force is too strong, the conveyance (paper feeding) accuracy is lowered. It might be. For this reason, at present, the actual situation is that it has not been put into practical use except for some large format printers that feed paper in the direction of gravity (uses the weight of the paper for paper feed).
[0012]
Accordingly, an object of the present invention is to more effectively prevent cockling of the recording medium in the recording apparatus, and to smoothly carry out the recording medium after the printing so that the spur roller is not marked. is there.
[0013]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, a recording medium conveying surface provided with a plurality of suction holes on the recording medium discharge side in the recording apparatus, a decompression chamber communicating with the plurality of suction holes, and the decompression chamber In a configuration in which a suction unit having a suction means for sucking air is placed and the recording medium is sucked and sucked through the suction holes provided in the suction unit, the recording is performed by blowing air from the suction holes after printing is completed. The medium was separated from the recording medium conveyance surface, and further moved in the carry-out direction as an auxiliary.
[0014]
In other words, the recording medium transport apparatus according to claim 1 includes a suction unit that sucks and holds the recording medium, and a recording medium transport unit that transports the recording medium from the upstream side to the downstream side of the suction unit. A recording medium conveyance surface provided with a plurality of suction holes, a decompression chamber communicating with the plurality of suction holes, and a suction means for sucking air in the decompression chamber, and the suction by the recording medium conveyance means A recording medium that transports the recording medium from the upstream side to the downstream side while adsorbing the recording medium supplied on the recording medium conveyance surface of the unit to the recording medium conveyance surface through a suction hole by a suction means during recording In the transport device, the suction unit is formed from the recording unit to the discharge unit, and the plurality of suction holes are provided over the entire recording medium transport surface, and at least the recording medium transport surface is provided. The discharge portion side is configured to assist discharge, and the recording medium transporting means uses blowing means for blowing air into the decompression chamber of the suction unit, and air blown into the decompression chamber by the blowing means. Auxiliary recording means for moving the recording medium away from the recording medium conveying surface and assisting movement in the discharging direction, and sucking the recording medium in a series of recording discharging operations, The suction means and the blowing means are switched and controlled so as to be separated and assist discharge.
[0015]
According to this configuration, the recording medium is supplied onto the recording medium conveyance surface of the suction unit by the recording medium conveyance unit, and is attracted onto the recording medium conveyance surface via the suction hole by the suction unit. The recording medium is printed by the recording head while being attracted onto the recording medium conveyance surface, and is gradually conveyed from the upstream side to the downstream side by the recording medium conveyance unit.
[0016]
Thereafter, when printing is completed, the recording medium is slightly lifted away from the surface of the recording medium conveyance surface by blowing air from the suction holes by the blowing means, and is directed toward the discharge direction, that is, the downstream side by the auxiliary conveyance means. Will be moved.
[0017]
Thus, after the printing is completed, the recording medium is smoothly discharged by moving away from the recording medium conveying surface of the recording medium conveying means and moving in the discharging direction. Sometimes the recording medium does not have a spur mark by the spur roller.
[0018]
According to a second aspect of the present invention, in the recording medium conveying device according to the first aspect, the auxiliary conveying means is configured such that each suction hole of the suction unit opens obliquely toward the recording medium discharge direction. It is characterized by being comprised. According to this configuration, when printing is finished, the recording medium is slightly lifted away from the surface of the recording medium conveyance surface by blowing air from the suction holes by the blowing means, and the suction holes are directed in the discharge direction. Therefore, it is moved in the discharge direction along the flow of air blown out from the suction hole.
[0019]
Further, in the recording medium transport apparatus according to claim 3, in the recording medium transport apparatus according to claim 1 or 2, the suction hole and the decompression chamber are communicated with each other by a suction hole, A taper is formed from the decompression chamber toward the recording medium support surface. As a result, the air passing through the suction hole is accelerated based on the shape thereof, and is blown out from the upper end of the suction hole, so that the recording medium is surely lifted by receiving a stronger flying force.
[0020]
According to a fourth aspect of the present invention, in the recording medium conveying apparatus according to any one of the first to third aspects, the auxiliary conveying means is configured so that the recording medium conveying surface of the suction unit is in the ejection direction. It is characterized by being formed so as to be inclined so as to become lower.
[0021]
According to this configuration, when printing is completed, the recording medium is slightly lifted away from the surface of the recording medium conveyance surface by blowing air from the suction holes by the blowing means, and the recording medium conveyance surface is in the discharge direction. By being formed so as to become lower, the recording medium is moved in the discharge direction by its own weight.
[0022]
According to a fifth aspect of the present invention, in the recording medium conveyance device according to any one of the second to fourth aspects, the spraying means is also used as a suction means, and the suction means is reversed. Thus, air is blown into the decompression chamber.
[0023]
According to this configuration, since the suction unit of the existing suction unit is reversed and the suction unit is reversed, air can be blown out from the suction hole as the spraying unit. The rise can be suppressed.
[0024]
Thus, a recording apparatus according to claim 5 is provided with the recording medium conveying apparatus.
[0025]
According to the recording apparatus having such a configuration, after the printing is finished, the recording medium is slightly lifted away from the surface of the recording medium transport surface by blowing air from the suction holes by the spraying means, and is slightly lifted by the auxiliary transport means. Since it is moved toward the discharge direction, that is, toward the downstream side, a conventional spur roller becomes unnecessary, and a spur mark by the spur roller is not attached to the recording medium at the time of discharge.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
A recording medium conveying apparatus according to an embodiment of the present invention will be described with reference to the drawings. The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. As long as there is no description of the effect, it is not restricted to these aspects.
[0027]
First, a first embodiment of the present invention will be described. FIG. 1 shows an ink jet printer as a recording apparatus incorporating a recording medium conveying apparatus according to the first embodiment of the present invention, and FIG. 2 shows a recording medium conveying apparatus as a main part thereof.
[0028]
As shown in FIG. 1, the ink jet printer 10 basically records a recording medium 1 accommodated in a paper tray 12a of an automatic paper feed (ASF) unit 12 attached obliquely to a printer body 11. The recording medium transport device 20 transports the recording medium 13 in the transport direction D to the recording unit 14 composed of the recording head 13 and the suction unit 100 located below the recording head 13. It has a configuration to discharge to.
[0029]
Further, a manual paper feed port 15 (see FIG. 2) not shown in FIG. 1 is formed on the back side of the printer main body 11, and the recording medium 1 that is inserted from the manual paper feed port 15 and fed is also provided. Similarly, during recording, the recording medium conveying device 20 sends the recording medium 14 to the recording unit 14 and discharges the recorded recording medium 1 out of the printer main body 11.
[0030]
In FIG. 1, the printer main body 11 includes a support frame 11a, an exterior cover 11b, and a discharge port 11c for the recording medium 1. As the recording medium 1, various types of paper such as OHP film, tracing paper, postcard, etc. can be used in addition to the dedicated paper for the inkjet printer and plain paper.
[0031]
Here, the recording head 13 is a guide shaft (see FIG. 5) arranged in parallel along directions E and F (main scanning direction) orthogonal to the conveyance direction D (paper feeding direction or sub-scanning direction) of the recording medium 1. The carriage 13a is slidably supported by a carriage 13a, and the carriage 13a slides on a guide shaft (not shown) by a timing belt driven by a DC motor 13b. The recording head 13 has a nozzle row composed of a plurality of nozzles such as 96 for each color, and prints ink supplied for each color from an ink cartridge 13c detachably mounted on the carriage 13a. According to the data, all or a part of the plurality of nozzles are ejected onto the recording medium 1 as fine ink particles.
[0032]
FIG. 2 is a cross-sectional view showing a configuration of a main part of the recording medium conveying apparatus 20, and FIG. 3 is a plan view of the suction unit.
[0033]
As shown in FIG. 2, the recording medium transport apparatus 20 includes a suction unit 100 that sucks and holds the recording medium 1 during recording, and a recording medium transport unit 120 that transports the recording medium 1 from the upstream side to the downstream side of the suction unit 100. It is equipped with.
[0034]
The suction unit 100 is disposed on the lower side of the recording head 13 for printing on a recording medium with the recording medium conveyance path L in between, and an upper suction unit 101 and a lower suction force generation unit 104. It is formed in the shape of a hollow box consisting of two upper and lower stages.
[0035]
As shown in FIG. 2, the suction unit 101 includes a decompression chamber 102 formed therein, a plurality of suction chambers 106 each formed as a substantially rectangular recess on the conveyance surface of the recording medium 1, and the suction chambers 106. Each has a plurality of suction holes 108 (see FIG. 3) having a smaller cross-sectional area than the suction chamber 106 extending in the vertical direction so as to communicate with the decompression chamber 102.
[0036]
The suction force generation unit 104 communicates with the decompression chamber 102 of the suction unit 101 through the communication hole 110 and includes a pump 112 having a centrifugal fan therein.
[0037]
The pump 112 is attached to a predetermined position below the decompression chamber 102 in a state where it communicates with the decompression chamber 102 via the communication hole 110, and the centrifugal fan rotates in the forward direction during recording. When the recording medium 1 is discharged after completion, the recording medium 1 rotates in the reverse direction as a spraying means that is an auxiliary conveying means of the recording medium conveying means 120.
[0038]
Here, the portion corresponding to the suction hole in the conventional suction structure is formed by the suction chamber 106 and the suction hole 108, and by forming the suction hole 108 by a small-diameter through hole, the characteristics of the pump are reduced. The utilization rate of the negative pressure that can be used is increased, and the suction chamber 106 that forms the surface facing the recording medium is formed as a substantially rectangular recess having a larger area so that a large suction force can be generated on the recording medium. It has become.
[0039]
The suction hole 108 may be tapered toward the upper surface as shown in FIG.
[0040]
The recording medium conveying means 120 is located below the recording medium conveying path L on the upstream side of the suction unit 100 and the recording head 13 so as to pick up and send out the recording medium 1 accommodated in the paper tray 12a one by one. , A paper feed roller 122 that feeds the recording medium 1 between the recording head 13 and the suction unit 100, and a driven roller 123 that is pressed against the paper feed roller 122 from above. The paper discharge roller and the spur roller are omitted.
[0041]
Here, the recording medium conveying unit 120 further includes an auxiliary conveying unit 126 and an air blowing unit 128.
[0042]
As shown in FIG. 2, the auxiliary conveying means 126 is formed so that the upper surface of the suction unit 101 of the suction unit 100 is flat in the print region facing the recording head 13, but in the region downstream from this print region. In this case, it is formed so as to be inclined so as to become lower from the upstream side toward the downstream side, that is, toward the discharge direction of the recording medium.
[0043]
In contrast, in the illustrated case, the blowing means 128 uses the pump 112 of the suction force generation unit 104 of the suction unit 100 to reversely rotate the pump 112, thereby causing the pump 112 to remove the suction unit 101. It is configured to blow out from the surface of the suction unit 101 through the suction hole 108 and the suction chamber 106.
[0044]
The pump 112 is switched to reverse rotation after the printing of the recording medium is completed, so that air is blown out from the surface of the suction unit 101.
[0045]
The recording medium transport apparatus 10 according to the embodiment of the present invention is configured as described above and operates as follows.
[0046]
First, when a recording command for the recording medium 1 stored in the paper tray 12a is input by a host computer or the like (not shown), the paper feeding roller of the ASF unit is driven to rotate, and the recording medium stored in the paper tray 12a. 1 is picked up and sent out one by one, and the paper feed roller 122 of the recording medium conveying means 120 is driven to rotate so that the recording medium 1 is conveyed between the recording head 13 and the suction unit 100.
[0047]
On the other hand, in the suction unit 100, the centrifugal fan starts to rotate in the forward direction, whereby the suction force by the pump 112 acts on the suction hole 108 and the suction chamber 106 via the communication hole 110 and the decompression chamber 102, and the suction suction state is established. It becomes.
[0048]
As a result, the recording medium 1 sent to the recording unit 14 is sucked and adsorbed to the printing area on the recording medium conveyance surface of the suction unit 100 and is conveyed while maintaining a close contact state. At the same time, the recording head 13 ejects ink particles onto the recording medium 1 while moving in the main scanning directions E and F above the recording medium 1 to perform image recording.
[0049]
When the printing of the recording medium 1 is completed, as shown in FIG. 2, the trailing edge of the recording medium 1 is released from between the paper feed roller 122 and the driven roller 124 of the recording medium conveying means.
[0050]
At this time, the pump 112 of the suction force generation unit 104 of the suction unit 100 is rotationally driven in the reverse direction, so that air is blown upward from the suction chamber 106 of the suction unit 100. As a result, the recording medium 1 is lifted away from the upper surface of the suction unit 101 of the suction unit 100.
[0051]
Here, when the suction hole 108 is tapered toward the upper surface as shown in FIG. 4, the air passing through the suction hole 108 is accelerated based on the shape of the suction hole 108 from the upper end of the suction hole 108. By blowing out vigorously, the recording medium 1 receives a stronger levitation force and surely rises.
[0052]
Since the upper surface of the suction part 101 of the suction unit 100 is inclined so as to become lower in the discharge direction, the recording medium 1 tends to fall to the lower side due to its own weight. After moving in the discharge direction along the inclined upper surface and being sent out from the recording unit 14, it is discharged out of the printer main body 11.
[0053]
At this time, as described above, since the recording medium 1 is sucked and held on the recording medium transport surface by the suction unit 100 during printing by the recording head 13, it does not float by cockling.
[0054]
At the time of ejection, the recording medium 1 is lifted by the air blowing from the recording medium conveyance surface of the suction unit 100, and drops by its own weight along the inclination of the recording medium conveyance surface, thereby using a conventional spur roller. Since it is carried out of the printer main body 11 without doing so, there is no such thing as a spur mark.
[0055]
FIG. 5 shows a second embodiment of the recording medium carrying device according to the present invention.
[0056]
In FIG. 5, the recording medium transport device 30 has substantially the same configuration as the recording medium transport device 20 shown in FIG. 2, and thus the same components are denoted by the same reference numerals and description thereof is omitted.
[0057]
The recording medium conveyance device 30 has a different configuration from the recording medium conveyance device 20 shown in FIG. 2 in the following points.
[0058]
That is, in the recording medium transport apparatus 30, the auxiliary transport means 31 is replaced by the suction unit 100 instead of the auxiliary transport means 31 by the inclined upper surface of the suction unit 101 of the suction unit 100 in the recording medium transport apparatus 20 shown in FIG. As shown in FIG. 5, the suction hole 108 provided on the upper surface of the suction portion 101 is inclined upward in the discharge direction so as to be inclined.
[0059]
According to the recording medium transport apparatus 30 having such a configuration, the recording medium transport apparatus 20 operates in the same manner as that shown in FIG. 2, and printing of the recording medium 1 is completed. As shown in FIG. When the trailing edge of 1 is released from between the paper feed roller 122 and the driven roller 124 of the recording medium conveying means, the pump 112 of the suction force generation unit 104 of the suction unit 100 is rotationally driven in the reverse direction. Air is blown upward from the suction chamber 106 of the suction unit 100. As a result, the recording medium 1 is lifted away from the upper surface of the suction unit 101 of the suction unit 100.
[0060]
Since each suction hole 108 of the suction unit 101 of the suction unit 100 is inclined obliquely toward the discharge direction, the recording medium 1 rides on an air flow ejected obliquely from each suction hole 108. After moving in the discharge direction along the flat upper surface of the suction unit 100 and being sent out from the recording unit 14, it is discharged out of the printer main body 11.
[0061]
Accordingly, the recording medium 1 is sucked and held on the recording medium conveyance surface by the suction unit 100 during printing by the recording head 13 as in the recording medium conveyance device 20 of FIG. Absent.
[0062]
Further, at the time of discharge, the recording medium 1 is lifted by air blowing from the recording medium conveying surface of the suction unit 100, and the air blowing direction causes the recording medium 1 to be carried out of the printer main body 11 without using a conventional spur roller. Therefore, there are no signs of spurs.
[0063]
【The invention's effect】
As described above, according to the present invention, when printing is finished, the recording medium is slightly lifted away from the surface of the recording medium conveying surface by blowing air from the suction holes by the blowing means, and the auxiliary conveying means. Is moved toward the discharge direction, that is, on the downstream side, based on the inclination of the recording medium conveying surface or the suction hole.
[0064]
Thus, after the printing is completed, the recording medium is smoothly discharged by moving away from the recording medium conveying surface of the recording medium conveying means and moving in the discharging direction. Sometimes the recording medium does not have a spur mark by the spur roller.
[Brief description of the drawings]
FIG. 1 is a diagram showing an ink jet printer as a recording apparatus incorporating a recording medium conveying apparatus according to the present invention. FIG. 2 is a schematic cross-sectional view of a recording medium conveying apparatus according to a first embodiment of the present invention. FIG. 4 is a partially enlarged cross-sectional view showing a modification of the suction hole of the suction unit in the recording medium transport apparatus of FIG. 2; FIG. 5 is a second embodiment of the present invention; 6 is a schematic cross-sectional view of a recording medium transport apparatus according to the present invention. FIG. 6 (a), (b), and (c) show only a recording section and a main section of a recording medium transport apparatus in a conventional ink jet printer. FIG. 7 is a diagram showing the spurs of an image recorded by a conventional ink jet printer.
1 Recording medium 10 Inkjet printer (recording device)
20, 30 Recording medium transport device 100 Suction unit 101 Suction unit 102 Decompression chamber 104 Suction force generation unit 106 Suction chamber 108 Suction hole 110 Communication hole 112 Pump 120 Recording medium transport means 121 Paper feed roller 122 Paper feed roller 123 Follower roller 126, 31 Auxiliary conveying means 128 Spraying means

Claims (6)

A suction unit for sucking and holding the recording medium;
A recording medium conveying means for conveying the recording medium from the upstream side to the downstream side of the suction unit;
The suction unit includes a recording medium conveyance surface provided with a plurality of suction holes;
A decompression chamber communicating with the plurality of suction holes,
A suction means for sucking air in the decompression chamber;
While the recording medium supplied onto the recording medium conveyance surface of the suction unit by the recording medium conveyance means is adsorbed on the recording medium conveyance surface via the suction holes by the suction means during recording, the recording medium is In the recording medium transport device for transporting from the downstream to the
The suction unit is formed from the recording unit to the discharge unit, and the plurality of suction holes are provided over the entire area of the recording medium conveyance surface,
At least the discharge unit side of the recording medium conveyance surface is configured to assist discharge,
The recording medium conveying means includes blowing means for blowing air into the decompression chamber of the suction unit;
Using the air blown into the decompression chamber by the blowing means, the auxiliary conveying means for moving the recording medium auxiliary from the recording medium conveying surface in the discharge direction,
In a series of recording and discharging operations, the recording medium is controlled by switching the suction means and the blowing means so as to suck the recording medium and to separate the recording medium to assist the discharging. .   2. The recording medium conveying apparatus according to claim 1, wherein the auxiliary conveying means is configured by each suction hole of the suction unit being opened obliquely toward the discharge direction of the recording medium. Recording medium transport device.   3. The recording medium conveying apparatus according to claim 1, wherein the suction hole and the decompression chamber communicate with each other through a suction hole, and the suction hole tapers from the decompression chamber toward the recording medium support surface. A recording medium transporting apparatus, wherein the recording medium transporting apparatus is formed.   4. The recording medium conveyance device according to claim 1, wherein the auxiliary conveyance unit is formed so as to be inclined so that a recording medium conveyance surface of the suction unit becomes lower in a discharge direction. 5. And a recording medium transporting device.   5. The recording medium conveying apparatus according to claim 1, wherein the blowing unit is also used as a suction unit, and air is blown into the decompression chamber by reversing the suction unit. Recording medium transporting apparatus.   A recording apparatus comprising the recording medium conveying apparatus according to claim 1.

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