JP2007152785A - Ink-jet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer device having highly-precise transfer precision while preventing a sheet material from floating in a printing area even when the sheet material is stretched by executing printing immediately under recording heads in a full multi-printer in which a plurality of the recording heads are fixedly arranged. <P>SOLUTION: A roll-paper printer executes recording-printing onto roll paper by a full multihead. Paper floating between the heads is prevented by providing a plurality of spurs spring-energized to the platen side between a plurality of the heads in the printing area in order to execute highly-precise paper transfer while preventing the paper floating in a wide printing area. An attraction generation means (electrostatic attraction) for attracting paper to a platen is arranged at a position opposite to a head face surface. Consequently, it is possible to prevent the paper floating at the position opposite to the head face surface so as to execute the highly-precise paper transfer by a transfer means on the paper transfer upstream side in a state of preventing the paper floating. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a recording apparatus having functions such as a printer, a copying machine, a facsimile, or the like, or a recording apparatus used as a composite electronic apparatus including a computer, a word processor, or the like, or an output apparatus of a workstation, and in particular, a colored liquid (ink). The present invention relates to a recording unit that performs recording by being applied to a recording material that is a sheet material, and a conveying unit that performs high-precision conveyance in a recording area of the recording unit.

  Recording devices having functions such as printers, copiers, facsimiles, etc., or composite electronic devices including computers and word processors, and recording devices used as output devices for workstations, are based on image information such as paper and plastic thin plates. An image is recorded on a recording material (recording sheet). Such a recording apparatus can be classified into an ink jet type, a wire dot type, a thermal type, a laser beam type, and the like according to the recording method.

  In a serial type recording apparatus that employs a serial scanning method in which main scanning is performed in a direction that intersects the conveyance direction (sub-scanning direction) of a recording material, an image is recorded by recording means mounted on a carriage that moves along the recording material. Is recorded (main scanning), and after the recording for one line is completed, a predetermined amount of paper is fed (pitch transport), and then the next line image is recorded on the recording material that has been stopped again (main scanning). The entire recording material is recorded by repeating the operation of scanning.

  On the other hand, in a line-type recording apparatus that records only by sub-scanning in the conveyance direction of the recording material, the recording material is set at a predetermined recording position, and after recording for one line at a time, a predetermined amount The entire recording material is recorded by repeating the operation of feeding the paper (pitch transport) and recording the next line all at once.

  Among the recording apparatuses described above, an ink jet recording apparatus (ink jet recording apparatus) performs recording by discharging ink from a recording means (recording head) onto a recording material, and the recording means can be easily made compact. Yes, high-definition images can be recorded at high speed. In addition, it is possible to record on plain paper without requiring special processing, low running costs, low noise due to the non-impact method, and recording color images using multi-colored inks. Has advantages such as being easy. In particular, a line type apparatus using a line type recording means in which a large number of ejection openings are arranged in the paper width direction can further increase the recording speed.

  7 to 8 are schematic cross-sectional views showing the structure around the recording area in the conventional ink jet recording apparatus. As shown in FIG. 7, the recording sheet P fed by a paper feeding device (not shown) is sandwiched between a conveyance roller 101 and a pinch roller 102, and a recording head is supported while a non-recording surface side is supported by a platen 106. 103 is conveyed to the recording area. The recording head 103 ejects ink toward the recording sheet P and records an image on the recording sheet P. After recording by the recording head 103, the recording sheet P is sandwiched between a discharge roller 104 and a spur 105 provided on the downstream side in the transport direction, and discharged by rotation of the discharge roller 104 and the spur 105.

  Let L be the distance between the recording head 103 and the recording sheet P. In such an ink jet recording apparatus, the ink landing position slightly changes depending on the distance between the recording head 103 and the recording sheet P. Therefore, if the distance is kept at a predetermined distance (for example, L) over the entire recording area, that is, if the recording sheet P can be completely aligned with the platen 106, a high-quality image can be obtained. Therefore, in the conventional ink jet recording apparatus, the recording sheet P is placed along the platen 106 disposed on the lower side of the recording head 103, so that the rotation shaft of the pinch roller 102 and the rotation shaft of the spur 105 are the rotation of the transport roller 101. The shaft and the rotating shaft of the paper discharge roller 104 are often offset from the platen 106 side.

  Further, since ink is used for recording in the ink jet recording apparatus, when the ink soaks into the recording sheet P, the recording sheet P expands, and the recording surface of the recording sheet P causes undulation (cockling) in the recording area. When the recording sheet P is greatly lifted from the platen 106 due to this undulation, not only the landing position of the ink is shifted, but also the recording surface becomes dirty due to the recording head 103 rubbing against the recording sheet P, or the recording head 103 May collide with the end of the recording sheet P and the recording head 103 may be deteriorated or damaged.

  Therefore, as shown in FIG. 8, in the conventional ink jet recording apparatus, relief portions 106 ′ and 104 ′ in which the recording sheet P can be displaced downward are provided on the platen 106 and the discharge roller 104, and the recording sheet P is placed on the platen 106 and A pushing spur 107 for forcibly pushing into the escape portions 106 ′ and 104 ′ of the paper discharge roller 104 is provided. By doing so, the recording sheet P regularly undulates within a predetermined height range, and the recording sheet P is prevented from being lifted.

For example, Patent Document 1 and Patent Document 2 can be cited as conventional examples.
Japanese Patent Laid-Open No. 11-216919 Japanese Unexamined Patent Publication No. 2005-89125

  However, as shown in FIG. 9, a plurality of recording heads arranged on the upper part of the platen 111 between the LF roller pair 113 and the paper discharge roller pair 116, the nozzle lengths of the recording heads are fixed to be equal to the sheet material width. In the full multi-printer form in which printing is performed at high speed while being conveyed by the conveying means immediately below the recording head, since there are a plurality of recording heads, the printing area immediately below the recording head is wide. In the conveyance device configuration with the pair 113 and the discharge roller pair 116, since the two pairs of conveyance rollers are long, the sheet material is prevented from being lifted by printing in the printing area (upper part of the platen 111). Difficult to do.

  Therefore, the present invention is a full multi-printer in which a plurality of recording heads are fixedly arranged, while printing is performed immediately below the recording head and the sheet material is elongated, while preventing the sheet material from floating in the printing area. An object of the present invention is to provide a transport apparatus having a highly accurate transport system.

  In order to achieve the above object, the recording apparatus of the present invention is a recording apparatus conveying apparatus for recording on a sheet material by a recording means, wherein the conveying apparatus is a recording unit arranged on the upstream side in the conveying direction of the recording means. A first conveying unit that conveys the sheet material to the area; a second conveying unit that is arranged downstream of the recording unit in the conveying direction; and that conveys the sheet material to a discharge port. This is an apparatus that conveys a sheet material while urging the sheet material in the region immediately below the recording means between the two conveying means toward the platen side by at least one spur and suction means arranged on the platen.

  The recording apparatus of the present invention has a recording apparatus configuration that performs printing while transporting a sheet material directly below a plurality of long recording heads each having a nozzle row length corresponding to the width of the sheet material.

  In the recording apparatus of the present invention, the spur of the second conveying means is disposed between the plurality of recording heads.

  In the recording apparatus of the present invention, the suction unit is disposed at a position facing the recording head as the recording unit.

  Further, in the recording apparatus of the present invention, the adsorption means is particularly an electrostatic adsorption system.

  Further, in the recording apparatus of the present invention, the suction unit arrangement position is particularly a position opposed to the head position and other than the opposed position around the nozzle arrangement position in the head.

  In the recording apparatus of the present invention, the sheet material is roll paper continuously connected in the conveyance direction.

  As described above, the recording apparatus of the present embodiment has the following effects.

  (1) A paper spur between the heads is prevented by a spur arranged between a plurality of long recording heads and urged in the platen direction, and further, electrostatic adsorption or the like arranged on the platen facing the head face surface. It is possible to provide highly accurate paper conveyance while preventing the paper floating just below the head by the suction means.

  (2) The position of the suction means such as electrostatic suction is set to an area where the head face surface is opposed and the nozzle row is avoided, so that high-precision paper conveyance that prevents paper floating is applied, and at the time of printing. It is possible to reduce adverse effects in the ink droplet flight direction due to the electric field in the space around the nozzle due to electrostatic adsorption of the ink droplets.

  Embodiments relating to the recording apparatus of the present invention will be described below in detail with reference to the drawings.

  A schematic diagram of a recording apparatus embodying the present invention is shown in FIG.

  The recording apparatus 100 according to the present embodiment is of a type called a roll paper printer that performs recording on a long recording medium.

  The recording medium (paper) 112 includes a label paper in which a label piece is temporarily attached to a mount, a tag paper with a perforation in a thick paper, and the like. Supplied to the paper transport unit.

  The transport unit is mainly composed of a transport motor 110 and a transport belt 111, and transports the paper in the direction of the arrow in the figure during the recording operation.

  Here, the roll unit 101 side on the conveyance path is a conveyance inlet, and the opposite side is a conveyance outlet.

  The recording unit of the recording apparatus 100 includes, for example, black (K), cyan (C), magenta (M), and yellow (Y) recording heads 102 to 105.

  Each recording head is an ink-jet line head having nozzle rows corresponding to the paper width.

  Black (K), cyan (C), magenta (M), and yellow (Y) inks are selectively ejected from these four recording heads 102 to 105, respectively, to perform color recording.

  The ejected ink is supplied from the ink cartridges (K) 106, (C) 108, (M) 109, and the ink cartridge (Y) 109 to the corresponding recording heads by a pump and tubes (not shown).

  The roll unit 101 includes a roll drive shaft 113 on which the roll paper 112 is mounted, a roll sensor lever 114 whose position changes due to the slack of the roll paper feeding portion, a roll motor (not shown) that drives the roll drive shaft 113, and the roll sensor lever 114. The roll motor (not shown) is driven and controlled according to the position to adjust the feeding speed of the roll paper 112.

  2 and 3 show a detailed cross-sectional view and a top view, respectively, of the conveying device for the printing area of this embodiment.

  A pair of LF rollers is disposed upstream of the recording heads 102, 103, 104, and 105 in the paper conveying direction, and is a first conveying unit that conveys the roll paper in the printing area directly below the recording head with high accuracy. A pair of paper discharge rollers is arranged downstream in the transport direction of the recording head, and the relationship between the transport speed (V2) of the paper discharge roller and the transport speed (V1) of the pair of LF rollers is V2> V1, Furthermore, by setting the relationship between the conveyance force (F2) of the paper discharge roller and the conveyance force (F1) of the LF roller to F2 <F1, the roll paper 112 is slipped between the pair of paper discharge rollers and the two rollers are separated from each other. Thus, the paper is transported directly under the recording head in a state where tension is applied to the roll paper.

  In addition, at least one spur is arranged between each of the recording heads 102, 103, 104, and 105 while urging the roll paper in the direction of pressing the roll paper toward the platen side, and prevents the roll paper 112 just below the recording head from floating. ing.

  FIG. 4 is a view showing the spur and a spur spring for biasing the spur in the platen direction. The spur 115 must transport the recording paper immediately after printing by the recording head in the printing area while pressing the paper float. However, depending on the spur shape, it may be necessary to press the printing surface of unfixed recording paper immediately after printing. The fixing ink on the recording paper is transferred to the surface, and the recording paper is soiled by the ink on the spur. Therefore, it is necessary to use a roller shape and material that are difficult to transfer to the spur surface even if it contacts the unfixed recording paper. As a configuration satisfying the spur conditions, for example, as shown in FIG. 4, the spur roller tip is made of a star-shaped roller with the tip of the roller sharpened with stainless steel to reduce the surface area in contact with the recording paper surface. Thus, it is possible to prevent transfer of unfixed ink to the spur. However, it is not limited to this shape. For example, in other spur configurations, even if the spur is made of Teflon (registered trademark) resin (PFA), ink transfer is prevented by using the water repellency that is the material characteristic of PFA. It may be a spur configured as follows.

  For example, as shown in FIGS. 2 and 3, one or more spurs as described above are provided between the line heads 102, 103, 104, and 105 (three are arranged in FIG. 3), and further, the spur spring is attached to the conveyor belt side by a spring. The pinching force generated by the bias can prevent a certain level of paper floating in a wide print area of the full multi-printer of this configuration. However, as shown in FIG. Since it can only be placed, it is possible to prevent overall paper lifting in a wide printing area, but it prevents paper lifting at a position facing the head face surface other than where the paper lifting is suppressed by spurs. It is difficult.

  In particular, in the case of thick paper (such as glossy special paper with thick recording paper), the paper in the area that is not pressed by the spur, even if the paper stiffens (paper waist) to prevent paper floating due to the paper waist Since the floating occurs partially, it is difficult to completely prevent the paper floating only by a spur in this configuration.

  FIG. 10 is a top view showing the electrostatic attraction means of the present embodiment.

  As means for preventing paper floating at the position facing the head face surface in the present embodiment, the electrostatic adsorption means 118 is partially disposed on the platen surface at the position facing the head face surface.

  Inside the platen 111, adsorption force generating means 118 is installed. The attracting force generating means 118 is composed of an electrode plate 118a made of a conductive metal and a ground plate 118b, and each tooth has a comb-like shape independently as shown in the figure so as to face each other in a direction perpendicular to the conveying direction. Multiple plates are installed on the surface of the platen 111.

  A plurality of electrode plates 118a and ground plates 118b are joined together, and terminals 118a 'and 118b', which are power-supplied portions with exposed patterns, are provided at the platen end, and are not shown by a high voltage line. A positive or negative voltage is applied to the terminal 118a 'of the electrode plate 118a by the high voltage power source, and the terminal 118b' of the ground plate 118b is grounded.

  As shown in FIG. 11, the conveying belt 131 has an adsorption force generating means 136 composed of an electrode plate 136a made of a conductive metal and an earth plate 136b in the adsorption force generation region, and includes a base layer 136c and a surface layer 136d. Protected in a sandwiched form. The base layer 136c and the surface layer 136d are made of a synthetic resin such as polyethylene or polycarbonate.

  When a voltage is applied to the electrode plate 118a in FIG. 10, an electric force is generated in the direction of the arrow in FIG. 11, and electric lines of force as shown in FIG. 11 are formed. An adsorption force is generated at a position above the platen 111 due to a potential difference between the electrode plate 118a and the ground plate 118b, and the same polarity as the voltage applied to the electrode plate 118a is formed on the recording surface of the recording paper P. Charge (surface potential) is generated.

  Incidentally, the adsorption force of the recording paper P is the lowest region where there is no conductive metal between the electrode plate 118a and the ground plate 118b.

  When a large amount of ink is ejected onto the recording paper P, the recording paper P swells and waviness (cockling) occurs. In this case, the cockling of the recording paper P is generated in a portion where there is no conductive metal between the electrode plate 118a and the ground plate 118b, which is the region having the lowest adsorption force, so that the recording paper P side of the recording paper P can be obtained. The float to the can be minimized.

  In the present embodiment, as shown in FIG. 10, the electrode plate 118a or 118b that generates the suction force is disposed at a position facing the face surface of the full multi-head. With such an electrode plate arrangement, a spur 115 dedicated to pressing the paper disposed between the full multi-heads and a paper float at a position opposite to the head face surface that cannot be suppressed by the spur are adsorbed to the platen by the electrostatic suction plate. As a result, it is possible to prevent paper floating in the printing area which is a wide area of the full multi-printer as a whole.

  Further, by preventing the paper floating by the spur and the electrostatic adsorption plate by this method, not only the paper floating countermeasure but also the load resistance for the paper conveyance can be reduced. In other words, if the entire printing area of this printer is prevented from being lifted by the electrostatic suction plate, the effect against paper lifting can be obtained, but the entire recording area is stuck on the platen. Although it becomes difficult to transport the paper due to load resistance with respect to the direction, by using both the spur of this embodiment and the electrostatic adsorption means, it is possible to reduce the load on the paper transport while preventing high-precision paper transport. Can be provided.

  In this embodiment, the electrostatic suction method is described as the suction means. However, other suction methods may be used. For example, an air suction system that arranges a sirocco fan on the back side of the platen and sucks and sucks recording paper from the back side of the platen with holes. Any other method may be used.

  As described above, according to the conveyance conditions of the present embodiment, a wide printing area of the full multi-printer is used in combination with a spur and suction means, and the paper is pressed between the heads by the spur, and further, the paper at a position facing the head face surface. By performing the pressing by an adsorption method such as an electrostatic method, it is possible to provide a high-precision paper conveying means for preventing paper floating that suppresses the conveying load as much as possible.

  A schematic view of a recording apparatus embodying the present invention is shown in FIG.

  The electrode plate 118 (118a, 118b) exposed on the platen surface described in Example 1 is disposed at a position facing the recording head face surface. In this example, the electrode plate 118 (118a, 118b) is a nozzle. Arranged at a position facing the head face surface other than the row 119. For example, in FIG. 5, a pair of electrode plates 118a and 118b is provided on the upstream side and the downstream side in the paper conveyance direction of the nozzle row (arranged at positions avoiding the nozzle row).

  If an electrode is provided in the vicinity of the nozzle when ink is ejected, an electric field is generated around the electrode, which causes a problem in that the flying direction of ink droplets during printing is out of order and image defects such as color misregistration occur.

  In the present embodiment, the paper floating at the position between the heads is suppressed by a spur, and the paper floating at the position facing the head face surface is suppressed by an adsorption means (electrostatic adsorption method), and the ink droplet flying direction is generated from the electrode plate. It is to provide a configuration that does not adversely affect the electric field.

  Here, the suction means is an electrostatic suction method, but even if another suction method is used, it may have an adverse effect, and for example, the recording paper is sucked by a sirocco fan that is generally considered as another suction method. Even with the air suction method that prevents paper pressing, there is a risk of changing the flying direction of the ink droplets due to the wind speed of the air. Similarly, air suction duct holes are provided at positions facing the face surface other than the nozzle rows. By taking such measures, it is possible to provide a configuration that does not affect the paper floating and the ink droplet flying direction.

1 is a cross-sectional view of an ink jet printer main body according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a conveyance device of the ink jet printer according to the embodiment of the present invention. FIG. 3 is a top view of the conveyance device of the ink jet printer according to the embodiment of the present invention. The perspective view which shows the spur and spur spring in the conveying apparatus concerning the Example of this invention. FIG. 3 is a schematic cross-sectional view illustrating a recording paper state in the transport device according to the embodiment of the invention. Sectional drawing of the electrostatic attraction board concerning 2nd Example of this invention. It is a schematic sectional drawing which shows the structure of the periphery of the recording area | region in the conventional inkjet recording device. FIG. 6 is a schematic cross-sectional view when the periphery of a recording area of a conventional recording apparatus is viewed from a conveyance direction. Full multi-printer configuration diagram The top view which shows the electrostatic adsorption means of a present Example The block diagram which shows the electrostatic attraction means of a present Example

Explanation of symbols

101 Recording device 101 Roll unit (paper feeding)
102 Recording head (K)
103 Recording head (C)
104 Recording head (M)
105 Recording head (Y)
106 Ink cartridge (K)
107 Ink cartridge (C)
108 Ink cartridge (M)
109 Ink cartridge (Y)
DESCRIPTION OF SYMBOLS 110 Conveyance motor 111 Conveyance belt 112 Recording medium 113 Registration roller pair 114 Registration motor 115 Spur 116 Spur spring 117 Conveyance drive roller 118 Adsorption power generation means 119 Nozzle row

Claims (7)

In the conveying device of the recording apparatus that records on the sheet material by the recording means,
The transfer device
First conveying means for conveying the sheet material to a recording area of the recording means arranged upstream in the conveying direction of the recording means;
A second conveying means arranged on the downstream side in the conveying direction of the recording means to convey the sheet material to a discharge port;
Furthermore, while urging the sheet material in the region immediately below the recording means between the first conveying means and the second conveying means to the platen side by at least one spur and the adsorbing means arranged on the platen A conveying apparatus that conveys a sheet material.   2. A recording apparatus configured to perform printing while transporting a sheet material immediately below a plurality of long recording heads having a nozzle row length corresponding to the width of the sheet material according to claim 1. Conveying device to do.   The spur of the said 2nd conveyance means of Claim 1, 2 is arrange | positioned between several recording heads, The conveying apparatus characterized by the above-mentioned.   The conveying device according to claim 1, wherein the suction unit is disposed at a position facing the recording head which is the recording unit.   5. A transport apparatus according to claim 1, wherein the suction means is an electrostatic suction system.   The conveying device according to claim 1, wherein the suction means arrangement position is a position opposite to the head position and other than the opposite position around the nozzle arrangement position in the head.   7. The conveying apparatus according to claim 1, wherein the sheet material of the conveying apparatus is roll paper continuously connected in the conveying direction.

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