JP3978715B2 - RECORDING MEDIUM CONVEYING DEVICE AND RECORDING DEVICE - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording medium conveying apparatus that conveys a recording medium, and a recording apparatus including the recording medium conveying apparatus.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, for example, an ink jet printer, which is one of recording apparatuses, has a configuration in which, for example, a sheet, which is one of recording media, is recorded while being sent to a recording unit by a paper transport device and is sent to the outside. FIG. 9A is a diagram showing only the main part of the paper transport device in such an ink jet printer. In such an ink jet printer, the paper 1 is recorded by the recording head 3 while being nipped and fed by the paper feed roller 2 and its driven roller 2a, and is nipped by the paper discharge roller 4 and the spur roller 4a as its driven roller. To be discharged.
[0003]
[Problems to be solved by the invention]
In an inkjet printer including the above-described conventional paper transport device, when an image on which a large number of ink droplets are ejected, such as a solid image, is recorded on the paper 1, the paper 1 absorbs a large amount of ink. As shown in FIG. 9B, so-called cockling that swells in a wavy shape toward the recording head 3 after recording may occur. When this cockling occurs and develops, the distance between the paper 1 and the recording head 3 becomes non-uniform, and the flying distance of the ink droplets varies, resulting in uneven recording, or the paper 1 becomes a recording head. There is a problem that it contacts 3 and gets dirty.
[0004]
If the span between the paper feed roller 2 and the paper discharge roller 4 is relatively short, these problems can be prevented as much as possible by suppressing the cockling described above within an allowable range. However, in an inkjet printer or the like, in the near future, it is necessary to increase the number of nozzles for each color nozzle row or to arrange a plurality of color nozzle rows in the conveyance direction of the paper 1 in order to further increase the recording speed. In these cases, the size of the recording head 3 becomes longer in the conveyance direction of the paper 1 as shown in FIG.
[0005]
As the recording head 3 becomes longer, the span between the paper feed roller 2 and the paper discharge roller 4 becomes longer. Therefore, the paper feed roller 2 and its driven roller 2a, the paper discharge roller 4 and a spur roller 4a as its driven roller. The cockling cannot be prevented at all in the structure in which the sheet is conveyed and discharged between the two. Then, the cockling exceeds an allowable range, and there may be a situation in which the structure itself that conveys and discharges between the two sets of rollers does not hold depending on such an ink jet printer having a large head length.
[0006]
In addition, such cockling is relatively small when a special paper of an ink jet printer is used as the paper 1, and becomes large when a plain paper is used. For this reason, normally, in the design of an ink jet printer or the like, the paper gap (paper 1 and recording head 3 in FIG. 9A) is taken into consideration when the paper floats due to cockling when plain paper is used. A) is increased. However, when the paper gap is large as described above, even when special paper that is not necessary is used, the ink particles ejected from the nozzles of the recording head 3 are bent and the deviation of the landing point is caused. It becomes larger by that amount and may hinder the improvement of recording quality.
[0007]
On the other hand, in recent years, various proposals have been made which mainly have a hollow box-like suction part on the paper transport surface and suck the paper with a suction pump or the like through a plurality of through-suction holes provided in the suction part. (Refer to Unexamined-Japanese-Patent No. 63-303781 and Unexamined-Japanese-Patent No. 3-270 etc.). Among these, as a means for eliminating the above-described cockling, there is proposed that a sheet is sucked or sucked on a platen or the like through the suction holes.
[0008]
However, in any case, only a through-hole is opened in the hollow box-like suction portion and suction is performed, and it is difficult to prevent the above-described cockling over the entire surface of the sheet in the recording portion. Further, in the conventional example described in the above publication, since the through hole is opened in the hollow box-like suction portion and suction is performed, if the suction force is too strong, the paper feeding accuracy may be reduced. 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).
[0009]
The present invention has been made in view of the various problems as described above, and an object of the present invention is to provide a recording medium transport apparatus capable of effectively preventing the development of cockling when transporting a recording medium, and the recording thereof. An object of the present invention is to provide a recording apparatus provided with a medium conveying apparatus.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, in the recording apparatus of the present invention, a recording unit that records recording data on a recording medium, and the recording medium supplied onto a recording medium conveyance surface including the recording unit are conveyed while being sucked. And a recording medium transport surface, wherein the recording medium transport surface is higher from a position beyond the recording section toward an upstream side in a transport direction of the recording medium. It is characterized by being inclined to become.
[0011]
As a result, even if cockling extending in the transport direction occurs on the recording medium after recording, the cockling is squeezed when the recording medium is transported while being lifted in the transport direction on the recording medium transport surface. As a result, the development of cockling can be prevented.
[0012]
In addition, the inclined surface is formed to be concavely curved. As a result, the leading edge of the recording medium travels along the recording medium conveyance surface curved in a concave shape, so that the recording medium can be smoothly conveyed without being held.
[0013]
Further, the inclined surface is formed to be convexly curved. As a result, the leading end of the recording medium travels along the recording medium conveyance surface curved in a convex shape, so that the recording medium can be smoothly conveyed without being held.
[0014]
Further, the inclined surface is formed flat.
[0015]
As a result, the recording medium is bent at a predetermined angle when entering the inclined surface, so that the force at the time of squeezing the cock ring can be applied intensively with a high force.
[0016]
The recording area for recording relative to the recording medium in the recording medium transportation surface is characterized in that it is flat.
[0017]
Thereby, since the gap between the recording medium and the recording head can be made uniform, the recording accuracy can be maintained in a highly accurate state.
[0018]
A plurality of suction holes provided in the recording medium conveying surface; a decompression chamber communicating with the plurality of suction holes; and suction means for sucking air in the decompression chamber, wherein the suction holes are provided in the decompression chamber. A suction unit including a suction hole communicating with the recording medium and a suction chamber in which an area of a suction surface facing the recording medium is larger than a cross-sectional area of the suction hole.
[0019]
Accordingly, an appropriate suction force can be generated, so that the recording medium can be sucked and transported while maintaining a high accuracy in feeding the recording medium.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0021]
FIG. 1 is a side view showing a recording medium conveying apparatus according to the first embodiment of the present invention. The recording medium transport apparatus 100 includes a suction unit 110 that sucks and holds a recording medium during recording, and a recording medium transport unit 150 that transports the recording medium from the upstream side to the downstream side of the suction unit 110. The suction unit 110 is disposed on the lower side of the recording head 231 for recording on a recording medium with the recording medium conveyance path L interposed therebetween. The upper suction part 120 and the lower suction force generation part 130 are formed in a hollow box shape having two upper and lower stages.
[0022]
The suction unit 120 includes a decompression chamber 121 formed therein, a plurality of suction chambers 123 formed as substantially rectangular recesses in the recording medium conveyance surface 122 as shown in FIG. In order to communicate with the chamber 121, a plurality of suction holes 124 having a smaller sectional area than the suction chamber 123 extending in the vertical direction are provided.
[0023]
The recording medium conveyance surface 122 is formed flat in the recording area 122A facing the recording head 231. In the area 122B downstream from the recording area 122A, the recording medium conveyance surface 122 moves from the upstream side toward the downstream side. It is formed on a surface that is inclined so as to be higher, that is, a surface that is warped upward in the discharge direction of the recording medium (hereinafter referred to as a reverse warped surface).
[0024]
The suction force generation unit 130 is communicated with the decompression chamber 121 of the suction unit 120 via the communication hole 131 and includes a pump 132 having a centrifugal fan therein. The pump 132 is attached to a predetermined position below the decompression chamber 121 so as to communicate with the decompression chamber 121 via the communication hole 131, and the centrifugal fan rotates during recording.
[0025]
The recording medium conveying means 150 includes a feeding roller 151 that feeds the recording medium between the recording head 231 and the suction unit 110, a driven roller 152 that is pressed against the feeding roller 151 from above, and the recording medium to the outside. A discharge roller 153 for discharging, and a spur roller 154 that comes into contact with the discharge roller 153 from above are provided. It should be noted that the discharge roller 153 and the spur roller 154 can be omitted by making the suction unit 110 movable in the discharge direction.
[0026]
As described above, the suction hole is constituted by the suction hole 124 and the suction chamber 123, and the suction hole 124 is formed by a small-diameter through hole, thereby increasing the utilization rate of the negative pressure that can be used for the characteristics of the pump 132. At the same time, by forming the suction chamber 123 as a substantially rectangular recess having a larger area than the suction hole 124, a large suction force can be generated with respect to the recording medium.
[0027]
Further, by forming the region 122B of the recording medium conveyance surface 122 as a reverse warp surface, the recording medium is conveyed while being raised in the conveyance direction on the region 122B of the recording medium conveyance surface 122, and is curved in a concave shape. The cockling that occurs after recording can be squeezed, and the development of cockling can be prevented. Furthermore, since the leading end of the recording medium proceeds along the region 122B of the recording medium conveying surface 122 that is curved in a concave shape, the recording medium can be smoothly conveyed without being held.
[0028]
In the embodiment shown in FIG. 1, the region 122B of the recording medium conveyance surface 122 is formed as an inclined surface curved in a concave shape, but may be formed as a flat inclined surface. In this case, since the recording medium is bent at a predetermined angle when entering the inclined surface, the force for squeezing the cock ring can be applied intensively with a high force. The elevation angle of the above inclined surface is desirably 2 ° to 15 °, preferably 5 ° to 11 °, for example.
[0029]
The recording medium transport apparatus 100 having such a configuration operates as follows. The feed roller 151 and the like are rotationally driven to feed the recording medium between the recording head 231 and the suction unit 110. On the other hand, the pump 132 is driven to apply a suction force to the suction hole 124 and the suction chamber 123 through the communication hole 131 and the decompression chamber 121. As a result, the recording medium is conveyed while being sucked and adsorbed on the recording medium conveying surface 122.
[0030]
At the same time, the recording head 231 performs recording by ejecting ink particles onto the recording medium while moving in the main scanning direction above the recording medium. As a result, cockling may occur in the recording medium after recording, but the recording medium is curved along a concave shape by being conveyed along the recording medium conveying surface 122 formed as a reverse warp surface, and the cockling is The development is blocked by squeezing. Then, the discharge roller 153 and the like are driven to rotate, and the recording medium on which recording is completed is discharged to the outside.
[0031]
FIG. 3 is a side view showing a recording medium conveying apparatus according to the second embodiment of the present invention corresponding to FIG. 1, and the same components as those of the recording medium conveying apparatus 100 shown in FIG. Therefore, the description is omitted. In the recording medium conveying device 160, the recording medium conveying surface 125 in the suction unit 120 is formed flat in the recording area 125A facing the recording head 231. However, the area 125B on the downstream side from the recording area 125A. Then, it is inclined so as to become lower from the upstream side toward the downstream side, that is, it is formed on a surface that warps downward in the recording medium discharge direction (hereinafter, referred to as a regular warped surface). 1 is different from the recording medium conveying apparatus 100 shown in FIG.
[0032]
As described above, even when the region 125B of the recording medium conveyance surface 125 is formed as a regular warp surface, the recording medium is conveyed on the region 125B of the recording medium conveyance surface 125 while hanging down with its own weight in the conveyance direction so as to be convex. Since it will be curved, the cockling generated after recording can be squeezed to prevent development. Furthermore, since the leading end of the recording medium proceeds along the region 125B of the recording medium conveying surface 125 that is curved in a convex shape, the recording medium can be smoothly conveyed without being held.
[0033]
In the embodiment shown in FIG. 3, the region 125B of the recording medium conveyance surface 125 is formed as an inclined surface curved in a convex shape, but may be formed as a flat inclined surface. In this case, since the recording medium is bent at a predetermined angle when entering the inclined surface, the force for squeezing the cock ring can be applied intensively with a high force. The depression angle of the above inclined surface is desirably formed to be, for example, 2 degrees to 15 degrees, preferably 5 degrees to 11 degrees.
[0034]
FIG. 4 is a side view showing a recording medium conveying apparatus according to the third embodiment of the present invention corresponding to FIG. 1, and the same components as those of the recording medium conveying apparatus 100 shown in FIG. Therefore, the description is omitted. In this recording medium conveying device 170, the recording medium conveying surface 126 in the suction unit 120 is formed so that both the recording area 126A facing the recording head 231 and the area 126B downstream from the recording area 126A are flat. 1 is different from the recording medium transport apparatus 100 shown in FIG. 1 in that a step 126C is formed between the areas 126A and 126B so that the recording area 126A is higher than the downstream area 126B.
[0035]
As described above, even when the step 126C is formed between the areas 126A and 126B of the recording medium conveying surface 126, the recording medium is conveyed on the area 126B of the recording medium conveying surface 126 while hanging down with its own weight in the conveying direction. Since it bends in a letter shape, the cockling that occurs after recording can be squeezed to prevent development. The step 126C is preferably formed to have a length substantially the same as the width in the width direction of the recording medium, for example, to a height of 1 mm to 5 mm.
[0036]
FIG. 5 is a perspective view showing an ink jet printer as a recording apparatus provided with the recording medium conveying apparatus of the present invention, and FIGS. 6 to 8 are a plan view, a front view, and a side view showing the main part. The ink jet printer 200 includes an automatic paper feed (ASF) unit 220 that is obliquely attached to the rear upper part of the printer main body 210, a recording unit 230 and a recording medium transport device 100 built in the printer main body 210. As the recording medium, various kinds of paper such as OHP film, tracing paper, postcard, etc. can be used in addition to the dedicated paper and plain paper of the ink jet printer 200.
[0037]
In this embodiment, the discharge roller 153 and the spur roller 154 are not required, the suction unit 110 that is movable in the discharge direction is provided, and the recording medium conveyance having the recording medium conveyance surface 125 of the warped surface shown in FIG. The inkjet printer 200 including the device 160 has a recording medium conveyance surface 122 having a reverse warp surface shown in FIG. 1 and a recording medium conveyance surface 126 having a step shown in FIG. The recording medium conveyance devices 100 and 170 having the spur roller 154 can be similarly applied.
[0038]
The ASF unit 220 includes a tray 221 that stores the paper 1, a paper feed roller 222 that pulls out and supplies the paper 1 from the tray 221, and the like. The recording unit 230 includes a carriage 233 on which the recording head 231 and the ink cartridge 232 are mounted, a DC motor 235 that moves the carriage 233 along a guide shaft 234 disposed in the main scanning direction, and the like. The recording head 231 has a nozzle row composed of a plurality of nozzles such as 96 for each color of cyan, magenta, yellow, light cyan, light magenta, light yellow, and black, for example.
[0039]
The ink jet printer 200 having such a configuration operates as follows. When a recording command for the paper 1 stored in the tray 221 is input by a host computer or the like (not shown), the paper feed roller 222 is rotated to pick up the paper 1 stored in the tray 221 one by one. Feed paper. Further, the feed roller 152 and the like are rotationally driven to feed the paper 1 between the recording head 231 and the suction unit 110.
[0040]
On the other hand, the pump 132 is driven to apply a suction force to the suction hole 124 and the suction chamber 123 through the communication hole 131 and the decompression chamber 121. Then, the sheet 1 is conveyed while being sucked and adsorbed to the recording medium conveying surface 125. At the same time, the DC motor 235 is driven to move the carriage 233 along the guide shaft 234 via the timing belt.
[0041]
At this time, the recording head 231 records the ink supplied from the ink cartridge 232 for each color by ejecting the ink on the paper 1 as fine ink droplets from all or a part of the plurality of nozzles according to the recording data. . As a result, cockling may occur in the paper 1 after recording. However, the paper 1 is curved along a convex shape by being conveyed along the recording medium conveyance surface 125 formed as a regular warp surface. The ring is squeezed to prevent its development. Then, the discharge roller 153 and the like are driven to rotate, and the recording-completed sheet 1 is discharged from the discharge port 201 to the outside.
[0042]
【The invention's effect】
As described above, according to the recording medium conveyance device and the recording apparatus of the present invention, even if cockling extending in the conveyance direction occurs in the recording medium after recording, the recording medium is conveyed by the recording medium. Since it is squeezed when it is transported while being curved in the transport direction on the surface, the development of cockling can be prevented. Accordingly, the distance between the recording medium and the recording head can be minimized and uniform, and stable conveyance can be performed, so that the recording accuracy can be improved and contamination due to contact between the recording medium and the recording head can be achieved. Can be prevented.
[Brief description of the drawings]
FIG. 1 is a side view showing a recording medium transport apparatus according to a first embodiment of the present invention.
2 is a plan view showing a recording medium conveyance surface of the recording medium conveyance apparatus in FIG. 1; FIG.
FIG. 3 is a side view showing a recording medium carrying device according to a second embodiment of the present invention.
FIG. 4 is a side view showing a recording medium carrying device according to a third embodiment of the present invention.
FIG. 5 is a perspective view showing an ink jet printer as a recording apparatus including the recording medium conveying apparatus of the present invention.
6 is a plan view showing a main part of the ink jet printer shown in FIG. 5;
7 is a front view showing a main part of the ink jet printer shown in FIG. 5. FIG.
8 is a side view showing a main part of the ink jet printer shown in FIG. 5;
FIG. 9 is a diagram illustrating only a main part of a paper transport device in a conventional ink jet printer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Paper 100 Recording medium conveyance apparatus 110 Suction unit 120 Suction part 121 Decompression chamber 122 Recording medium conveyance surface 123 Suction chamber 124 Suction hole 125 Recording medium conveyance surface 126 Recording medium conveyance surface 130 Suction force generation part 131 Communication hole 132 Pump 150 Recording medium Conveying means 151 Feed roller 152 Followed roller 153 Discharge roller 154 Spur roller 160 Recording medium conveying device 170 Recording medium conveying device 200 Inkjet printer 210 Printer main body 220 ASF unit 221 Tray 222 Paper feeding roller 230 Recording unit 231 Recording head 232 Ink cartridge 233 Carriage 234 Guide shaft 235 DC motor

Claims (6)

A recording apparatus comprising: a recording unit that records recording data on a recording medium; and a recording medium conveyance unit that conveys the recording medium supplied onto a recording medium conveyance surface including the recording unit while adsorbing the recording medium. There,
The recording apparatus, wherein the recording medium conveyance surface is inclined so as to increase from an upstream side to a downstream side in a conveyance direction of the recording medium from a position beyond the recording unit.   The recording apparatus according to claim 1, wherein the inclined surface is formed to be curved in a concave shape.   The recording apparatus according to claim 1, wherein the inclined surface is formed to be curved in a convex shape.   The recording apparatus according to claim 1, wherein the inclined surface is formed flat.   The recording apparatus according to claim 1, wherein a recording area for recording on the recording medium on the recording medium conveyance surface is formed flat.   A plurality of suction holes provided in the recording medium conveying surface; a decompression chamber communicating with the plurality of suction holes; and suction means for sucking air in the decompression chamber, wherein the suction holes communicate with the decompression chamber. 6. A suction unit comprising: a suction hole that includes a suction chamber and a suction chamber having a suction surface facing the recording medium larger than a cross-sectional area of the suction hole. The recording device according to item.

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