JP2006219235A - Recording medium conveying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliabiable recording medium conveying device capable of providing a high-quality image without being influenced by mist. <P>SOLUTION: A recording device provided with a conveying means using a conveying belt for conveying paper by attracting it by electrostatic force by applying a voltage thereto, and a recording/printing means at a position facing to it is characterized by applying the electrostatic force such that a recording paper surface potential is set lower than a mist attracting voltage at a head position of a recording means in recording. The conveying belt is characterized by that an electrostatic force generation means is a pectinate electrode formed on a conveying belt surface. In addition, the recording device is characterized by always applying the electrostatic force in a recording/printing means passing area. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a conveyance device using a conveyance belt and a recording medium conveyance device provided in a recording apparatus that records an image on an object conveyed by the conveyance device, and more particularly to an electrode provided on the conveyance belt. The present invention can be suitably used for a conveying apparatus that applies a voltage and electrostatically adsorbs an object to be conveyed to the conveying belt, and a recording apparatus including the conveying apparatus.

  Conventionally, as a recording apparatus, there is a recording apparatus such as an ink jet printer.

  In general, an inkjet recording apparatus is an apparatus that performs recording on a recording medium by ejecting ink from a recording head. The recording head can be easily downsized, high-definition images can be recorded at high speed, the running cost is low, the non-impact method reduces noise, and color images using multicolored inks. Has the advantage of being easy to record.

  In particular, a full line type apparatus using a line type recording head in which a large number of nozzles are arranged in the paper width direction can further increase the recording speed.

  However, in the full-line type apparatus, the distance from the most upstream recording head to the most downstream recording head becomes considerably long, so that the recording sheet is lifted in the recording area, and the recorded image Cause disturbances and jams.

  Therefore, as a means for urging downward so that the recording sheet does not float up, a method is generally known in which a voltage is applied to an electrode provided on the conveyance belt to generate an electric force to attract the recording sheet.

  In such an ink jet recording apparatus, the recording sheet fed by the sheet feeding device is conveyed while being adsorbed and held on the upper surface of the conveying belt by the adsorption force generating means provided on the conveying belt, and is imaged by the recording head in the recording area. Is recorded.

FIG. 6 is a schematic configuration diagram of the entire recording apparatus according to the prior art. A recording apparatus having an automatic paper feeder is composed of (I) paper feed unit, (II) transport belt unit, (III) recording head unit, and (IV) paper discharge unit. The description will be given with reference.
(I) Paper Feed Unit In the drawing, the paper feed unit starts the paper feed operation by rotating the pressure plate 21 on which the recording sheets P are stacked and the feeding rotating body 122 that feeds the recording sheets P. The pressure plate 121 can rotate around the rotation axis a and is urged by the pressure plate spring 124 to the feeding rotating body 122.

  A separation pad 125 made of a material having a large coefficient of friction such as an artificial skin that prevents double feeding of the recording sheet P is provided at a portion of the pressure plate 121 that faces the feeding rotating body 122.

  Furthermore, a release cam (not shown) that covers a corner in one direction of the stacked recording sheets P and releases the contact between the separation claw 126 for separating the recording sheets P one by one, the pressure plate 121, and the feeding rotating body 122. Is provided.

  In the above configuration, in the standby state, the release cam pushes down the pressure plate 121 to a predetermined position, and the contact between the pressure plate 121 and the feeding rotating body 122 is released.

  In this state, when a driving force (not shown) is transmitted to the feeding rotary body 122 and the release cam by a gear or the like, the release cam moves away from the pressure plate 121 and the pressure plate 121 rises, and the feeding rotary body 122 and the recording sheet P abuts.

  Then, the recording sheet P is picked up and started to be fed along with the rotation of the feeding rotating body 122, separated one by one by the separation claw 126, and sent to the conveying belt unit.

  The feeding rotating body 122 rotates until the recording sheet P is fed into the conveying belt portion, and again enters a standby state in which the contact between the recording sheet P and the feeding rotating body 122 is released, and the driving force is cut off.

Reference numeral 190 denotes a feeding rotating body for manual sheet feeding. The recording sheet P placed on the manual feed tray 191 is fed by the feeding rotating body 190 in accordance with a recording command signal of the computer and is conveyed to the conveying belt unit.
(II) Conveying Belt Unit The conveying belt unit has a conveying belt 131 that sucks and conveys the recording sheet P. The conveyor belt 131 is driven by a driving roller 134 and is wound around a conveyor roller 132 and a pressure roller 135 which are driven rollers.

  The conveying roller 132 and the driving roller 134 are rotatably attached to the platen 130, and the pressure roller 135 is rotatably attached to the other end of the arm 150 that is swingably attached to the platen 130. The belt 150 is pressed by the spring 151 to apply tension to the conveyor belt 131.

  The platen 130 is located below the conveyor belt 131 and serves to regulate the downward displacement of the conveyor belt 131.

  A pair of suction rollers 133 that are driven by the conveying belt 131 and opposed to be sandwiched are provided in contact with each other at a position downstream of the conveying roller 132. The suction roller 133 guides the recording sheet P to the recording head unit 107 by pressing the upper roller against the conveying belt 131 by a spring (not shown) with respect to the lower roller.

  The PE sensor 123 includes a PE sensor lever and a photo sensor, and detects the leading edge and trailing edge of the recording sheet P.

  Further, a recording head unit 107 that forms an image based on image information is provided on the downstream side of the conveyance roller 132 in the recording sheet conveyance direction.

  In the above configuration, the recording sheet P transported to the transport belt unit is sent to a pair of rollers with the suction roller 133. At this time, the leading edge of the conveyed recording sheet P is detected by the PE sensor lever 123 to obtain the printing position of the recording sheet P.

Further, the recording sheet P is conveyed by rotating a conveying belt 131 via a driving roller 134 by a paper feed motor described later.
(III) Recording Head Unit The recording head unit 107 includes four line-type ink jet recording heads in which a plurality of nozzles are arranged in a direction orthogonal to the conveyance direction of the recording sheet P, and these are upstream in the conveyance direction of the recording sheet P. To 107K (black), 107C (cyan), 107M (magenta), and 107Y (yellow) in this order at predetermined intervals.

  The recording heads 107K, 107C, 107M, and 107Y can apply heat to the ink with a heater or the like. The heat causes the ink to boil, and ink is ejected from the nozzles of the recording heads 107K, 107C, 107M, and 107Y due to pressure changes caused by bubble growth or contraction due to the film boiling, and an image is formed on the recording sheet P. Is done.

The head holder 170 is disposed so as to be movable up and down by shafts 172 with ball screws provided at four places on the left and right and front and rear sides, and can be stopped with high accuracy at a certain height. The cap 171 is disposed so that the position immediately below the head and the retracted position can be translated by a driving unit (not shown), and when not printing, the head holder 170 is raised, and the cap 171 is moved to a position directly below the head to cover the head surface. Enables long-term storage.
(IV) Paper Discharge Unit The paper discharge unit includes a paper discharge roller 141 and a spur 142, and the recording sheet P on which an image is formed by the recording head unit 107 is sandwiched between the paper discharge roller 141 and the spur 142, and is conveyed. Then, it is discharged to the paper discharge tray 143.

  The paper discharge roller 141 is driven by the rotational force of the drive roller 134 transmitted by transmission means (not shown).

  Note that the outer periphery of the spur 142 has a pointed concavo-convex surface and prevents the spur 142 from being transferred to the spur 142 when the printed surface after recording rolls.

  Next, the configuration and operation of the suction conveyance of the conventional conveyance device will be described with reference to FIGS.

  FIG. 7 is a schematic configuration diagram of a transport apparatus according to the prior art.

  In the figure, 131 is a conveyor belt that moves while adsorbing and holding the recording sheet P, and is made of synthetic resin such as polyethylene or polycarbonate having a thickness of about 0.1 mm to 0.2 mm, and forms an endless belt shape. is doing.

  A power supply brush 152 is connected to a high-voltage power source (not shown) that generates a predetermined high voltage, and is provided to be joined to the transport belt 131.

  The conveying belt 131 is provided with an attracting force generating means 136 which will be described later. When the power supply brush 152 applies a voltage of about 0.5 kV to 10 kV to the attracting force generating means 136, an attracting force is generated in the conveying belt 131. To do.

  The conveyance roller 132, the driving roller 134, and the pressure roller 135 are rollers that support the conveyance belt 131 and apply appropriate tension, and the driving roller 134 is coupled to the paper feed motor 160.

  In addition, an upper roller of the suction roller 133 as a pressing unit that presses the recording sheet P toward the conveyance belt is rotatably attached to the paper pressing roller support member 139, and the suction roller 133 is conveyed by the conveyance belt by a biasing unit (not shown). It is biased to the 131 side.

  A cleaning blade 137 is provided for roughly scraping off ink that has accidentally landed on the conveying belt 131 due to a jam or the like, and is disposed at a position facing the driving roller 134.

  A pair of cleaning rollers 138 is provided to be sandwiched between the conveying belts 131. The cleaning rollers 138 can absorb ink to cleanly remove dirt such as ink adhering to the conveying belts 131, and prevent deterioration in durability. Therefore, it is formed of a sponge with a small pore size (preferably 10 μm to 30 μm).

  A neutralizing brush 153 is a neutralizing unit for the conveyor belt 131.

  In the above configuration, the recording sheet P conveyed from the paper feeding unit is nipped on the conveyance belt 131 by the conveyance roller 132 and the suction roller 133 and pressed to the conveyance belt 131 side.

  Then, the recording sheet P is attracted to the flat portion of the transport belt 131 by the electric force generated by the attracting force generating unit 136 to which a voltage is applied from the power supply brush 152.

  The recording sheet P adsorbed on the conveyance belt 131 is guided to the recording head unit 107 and conveyed in the direction of arrow A by the paper feed motor 160 and the driving roller 134 while being printed by the recording heads 107K, 107C, 107M, and 107Y.

  The conveying belt 131 is cleaned by the cleaning roller 138 and then discharged by the discharging brush 153.

  Next, the attracting force generating means 136 will be described with reference to FIGS.

  FIG. 8 is a schematic configuration diagram of the conveyor belt as viewed from the direction of the arrow f in FIG. 7, and shows an electrode pattern and the like of the suction force generating means provided on the conveyor belt. FIG. 9 is a cross-sectional view of the transport belt as viewed from the direction of arrow a in FIG. 8, and FIG. 10 is a cross-sectional view of the transport belt as viewed from the direction of arrow b in FIG.

  In the drawing, an adsorption force generating means 136 is provided inside the conveyor belt 131. The attracting force generating means 136 is composed of a positive electrode plate 136a and a negative electrode plate 136b made of a conductive metal. As shown in the figure, each tooth independently has a comb-like shape and is perpendicular to the belt conveying direction. A plurality of conveyor belts 131 are provided so as to face each other.

  At both ends in the moving direction of the conveyor belt 131, power-supplied portions 136a ′ and 136b ′, each having an exposed pattern, are provided with a distance equal to or longer than the width of each electrode 136a and 136b in the belt moving direction. A conductive power supply brush 152 and a charge eliminating brush 153 are provided in contact with each other at a predetermined pressure.

  The power supply brush 152 applies a positive voltage from a high-voltage power supply (not shown) to the power-supplied portion 136a 'of the positive electrode plate 136a and a negative voltage to the power-supplied portion 136b' of the negative electrode plate 136b.

  As shown in FIGS. 9 and 10, the conveying belt 131 includes a base layer 136c that has an attracting force generating means 136 composed of a plus electrode plate 136a and a minus electrode plate 136b made of a conductive metal in the attracting force generation region. And a surface layer 136d are provided so as to be protected in a sandwiched manner. 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 136a, an electric force is generated in the direction of the arrow, and electric lines of force as shown in the figure are formed. Then, an adsorption force is generated at an upper position of the conveyance belt 131 due to a potential difference between the electrode plate 136a and the ground plate 136b, and the recording sheet P is adsorbed. On the recording surface of the adsorbed recording sheet P, a charge (surface potential) having the same polarity as the voltage applied to the electrode plate 136a is generated.

  Note that the adsorption force received by the recording sheet P is the weakest at the portion where there is no conductive metal between the electrode plate 136a and the ground plate 136b.

  When a large amount of ink is ejected onto the recording sheet P, the recording sheet P swells and waviness (cockling) occurs. Also in this case, since the recording sheet P is attracted to the conveying belt 131 side by the attracting force of the attracting force generating means 136, the recording sheet P does not float to the recording head portion 107 side, and the recording heads 107K, 107C, 107M, There is no contact between 107Y and the recording sheet P, and stable recording can be performed.

  In addition, the cockling is generated in a distributed manner in a region where the suction force on the conveyor belt 131 is the weakest (a portion where there is no conductive metal between the electrode plate 136a and the ground plate 136b). The floating to the part 107 side can be suppressed to the minimum.

  Further, even when the end of the recording sheet P is wavy or curled due to changes in the environment such as temperature and humidity, the recording sheet P is pressed against the conveying belt 131 by the paper pressing roller 140, Since the sheet can be conveyed to the suction force generation region with the curl removed, stable suction can be performed in the recording head unit 107.

  FIG. 11 is a graph showing changes in the surface potential immediately below the head when the recording paper is conveyed in the apparatus having the above configuration.

  Just below the head, the positive electrode and the negative electrode alternately pass in synchronization with the transport speed (recording speed). At that time, since power is always supplied in the printing region, a surface potential substantially equal to the applied voltage is held from the belt surface.

  Also, when the adsorbed recording paper passes, the direction potential decreases because of high volume resistance, but the applied voltage is high, and the surface potential decreases because the recording paper itself is thin. A potential suitable for the electrode appears.

  Such a recording apparatus is described in Patent Document 1, for example.

JP 2003-160253 A

  However, in the case of the prior art as described above, the following problems have occurred.

  That is, in an ink jet recording apparatus, fine ink unnecessary for image formation called mist is generated at the time of printing simultaneously with main droplets that actually form a print image. This is mainly caused by the impact that has landed when the main droplet is separated from the head nozzle. The generated mist is floated around the head because the amount and mass are very small compared to each other.

  In addition, it has been found that ink has a charge when the head is ejected. Therefore, the mist is similarly charged and present on the air.

  As a result, in the prior art as described above, when a potential difference occurs on the surface of the recording paper, the main droplet has a high ejection speed and occurs in a direction perpendicular to the force flight direction by electrolysis during flight. However, since the energy is large, the landing position does not affect the image.

  However, since it is floating in the mist, it hardly waits for kinetic energy and holds only the electric charge. Therefore, if there is a potential difference in the recording paper, it is directly affected.

  As a result, it is attracted to the portion holding the charge opposite to the charge held by the mist and landed on the recording paper. As an image, it gathers on the electrode holding the opposite charge, and that portion becomes dark, and it is visually recognized as density unevenness, causing deterioration in image quality.

  The present invention has been made in order to solve the above-described problems of the prior art, and the object of the present invention is a highly reliable recording medium conveying apparatus capable of obtaining a high-quality image without being affected by mist. Is to provide.

  In order to achieve the above object, the present invention provides a recording apparatus provided with a conveying means using a conveying belt that applies a voltage and attracts and conveys paper by electrostatic force, and a recording printing means at a position opposite to the conveying means. The electrostatic force is applied so that the recording paper surface potential is lower than the mist adsorption voltage at the recording means head position.

  Further, in the transport belt, the electrostatic force generating means is a comb-shaped electrode provided on the transport belt surface.

  Further, it is characterized in that it is always applied in the recording / printing means passage region.

  Further, the recording paper is provided with humidifying means between the recording means leading position and the voltage application start position so that the recording sheet surface potential is uniform at the recording means leading position.

  Further, the recording / printing means is an ink jet system.

  Further, the humidifying means is an ink jet recording means.

  According to the present invention, the electrostatic force is applied so that the recording paper surface potential is lower than the mist adsorption voltage at the recording means head position during recording. It is possible to provide a highly reliable recording medium conveying apparatus capable of obtaining an image.

  Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.

  A conveying apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic configuration diagram of a transport apparatus according to a conventional technique according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a transport belt according to an embodiment of the present invention, and a graph showing surface potential, and FIG. It is sectional drawing of the conveyance belt which concerns on embodiment of invention, and is the graph which showed the surface potential just under the head which concerns on embodiment of this invention.

  A conveyor belt 31 provided with an adsorbing force generating means 36 (the same configuration as that of the prior art) by a comb electrode is driven by a driving roller 34 and is wound around a conveyor roller 32 and a pressure roller 35 which are driven rollers.

  The conveying roller 32 and the driving roller 34 are rotatably attached to the conveying device frame 30, and the pressure roller 35 is rotatably attached to the other end of an arm 50 that is swingably attached to the conveying device frame 30. The arm 50 is pressed by the spring 51 to apply tension (19.6 N) to the conveyor belt 31.

  A pair of suction rollers 33 is arranged at a position downstream of the transport roller 32 so as to sandwich the transport belt 3. The upper roller of the suction roller 33 is brought into pressure contact with the transport belt 31 by the spring 38 to introduce the recording sheet P. Further, the upper roller of the suction roller 33 is electrically connected to a main body frame (not shown), thereby removing charges accumulated in the surface layer 36d of the conveyor belt 31.

  An upper guide 27 and a lower guide 28 for guiding the recording sheet P are disposed at the entrance of the conveyance belt 31 to which the recording sheet P is conveyed. Further, the upper guide 27 is provided with a PE sensor lever for transmitting the leading edge and trailing edge detection of the recording sheet P to a PE sensor (not shown).

  Further, a recording head 7 that forms an image based on image information is provided on the downstream side of the conveyance roller 32 in the recording sheet conveyance direction.

  In the above configuration, the recording sheet P conveyed to the conveyance belt 31 is guided by the upper guide 27 and the lower guide 28 and is sent to the suction roller 33. At this time, the leading edge of the conveyed recording sheet P is detected by the PE sensor lever to obtain the printing position of the recording sheet P.

  Then, the recording sheet P is conveyed by the conveyance belt 31 rotating via a driving roller 34 by a paper feed motor described later.

  In the figure, 31 is a conveyor belt that moves while adsorbing and holding the recording sheet P, and is made of synthetic resin such as polyethylene or polycarbonate having a thickness of about 0.1 mm to 0.2 mm, and forms an endless belt shape. ing.

  A power supply brush 52 is connected to a high-voltage power source (not shown) that generates a predetermined high voltage, and is provided to be joined to the transport belt 31.

  The conveying belt 31 is provided with an attracting force generating means 36 to be described later. When the power supply brush 52 applies a voltage of about 0.5 kV to 10 kV to the attracting force generating means 36, the attracting force is generated on the conveying belt 31. To do.

  The conveying roller 32, the driving roller 34, and the pressure roller 35 are rollers that support the conveying belt 31 and apply appropriate tension, and the driving roller 34 is coupled to the paper feed motor 60.

  In addition, an upper roller of the suction roller 33 as a pressing unit that presses the recording sheet P toward the conveyance belt is rotatably attached to the paper pressing roller support member 39, and the suction roller 33 is conveyed by the conveyance belt by an unillustrated urging unit. It is biased to the 31 side.

  Reference numeral 53 denotes a static elimination brush which is a static elimination means for the conveyor belt 31.

  In the above configuration, the recording sheet P conveyed from the sheet feeding unit is sandwiched between the conveyance roller 31 and the suction roller 33 on the conveyance belt 31 and pressed to the conveyance belt 31 side.

  Then, the recording sheet P is attracted to the flat portion of the transport belt 31 by the electric force generated by the attracting force generating unit 136 to which a voltage is applied from the power supply brush 52.

  The recording sheet P adsorbed on the conveying belt 131 is guided to the recording head unit 7 and is humidified and printed by the humidifying means 40 and the recording heads 7K, 7C, 7M, 7Y, which are the most characteristic features of the present invention, and the paper feed motor 60 is printed. And conveyed by the drive roller 34.

  In the present embodiment, a recording head is used as the humidifying means. It is generally known that a processing liquid is used to improve the fixing speed as the speed increases and to improve the color developability by fixing the ink on the surface of the recording paper. This can be achieved not only by fixing the ink on the surface of the recording paper but also by actively performing fixing by reacting scientifically with the treatment liquid.

  This apparatus is also necessary for performing high-speed printing, and is originally realized by printing the same image as the ink to be reacted.

  In the present embodiment, a colorless processing liquid composed of 80% water component is used, and a recording head for printing the processing liquid is disposed upstream of the recording head that originally forms an image, and not a recording image but a recording image. The recording paper is humidified by printing a predetermined image up to an image area in a wider range that is not affected by mist.

  By using the recording head, detailed setting of the image area and management of the humidification amount can be easily performed.

  The recording paper that has passed through the humidifying means is subjected to a printing operation by a process similar to the prior art, and an image is formed and discharged.

  Next, the change in surface potential by using the means in this embodiment will be described.

  FIG. 2 is a cross-sectional view showing the surface potential on the conveyor belt 31 when ± 1.0 kV is applied to the attracting force generating means 36 by the power supply brush 52 positioned in front and behind, respectively, across the head. FIG. 3 is a diagram showing the distribution of charges at that time.

When a high voltage is applied to the power supply plates 36a and 36b by the power supply brush, the surface layer 36d having a volume resistance of 1 × 10 ¹² Ω · cm ³ is polarized with respect to each voltage, and the belt surface is subjected to the applied voltage according to the applied voltage. Produces surface potential. At this time, a minute current flows, but the amount of current flowing can be controlled by the low seat resistance of the surface layer.

  During recording, a constant high voltage is always applied in the printing area where the recording head 7 is arranged. Therefore, immediately below the head, each electrode plate passes according to the conveyance speed, so surface charges close to a sine wave are repeatedly generated. Will do.

  As shown in FIG. 11, in the prior art, when the recording paper is adsorbed, the recording paper is slightly affected by the environment and the recording paper, but is slightly reduced due to the volume resistance of the recording paper because the applied voltage is large. Value. However, it is impossible to stably reduce the voltage below the mist generation voltage.

  However, in the present embodiment, since the recording paper is uniformly humidified by the humidifying means, a child that lowers the recording paper surface voltage below the mist generation voltage is possible as shown in FIG. For example, it is possible to print about 10 to 20% of the processing liquid with 4 pl and 1200 dpi printing on the plain paper and perform humidification.

  In recent years, miniaturization of ink main droplets has progressed to enable higher recording speed and higher definition. As a result, the distance between the recording sheet and the recording head has been reduced, and the discharge speed has been increased. Yes. For this reason, in order to obtain high-definition image quality, it is required to carry the sheet with high accuracy while keeping the distance between the recording sheet and the recording head close and constant. In particular, in a 1PASS high-speed recording apparatus using a line head, this is a factor that directly affects image quality.

  According to the present embodiment, it is possible to carry a sheet while maintaining a constant interval without causing mist adhesion due to the influence of the surface potential of the recording paper in a state where a high voltage capable of obtaining a sufficient recording paper holding force is applied.

<Embodiment 2>
In the above embodiment, the recording head 7 is used as the humidifying means 40 and the recording paper is neglected by the processing liquid. However, the present invention is not limited to the above configuration as long as it can humidify the recording paper.

  For example, as shown in FIG. 5, the water holding container 41 is provided using the suction roller 33 as the humidifying means 40, and the upper roller of the suction roller is arranged in the lower part, and a certain amount of water is transferred from the water holding container 41 to the recording paper. You may make it do.

It is a schematic block diagram of the conveying apparatus which concerns on the prior art which concerns on Embodiment 1 of this invention. It is the graph which showed sectional drawing and surface potential of the conveyance belt which concerns on Embodiment 1 of this invention. It is sectional drawing of the conveyance belt which concerns on Embodiment 1 of this invention. 3 is a graph showing a surface potential directly under the head according to Embodiment 1 of the present invention. It is a schematic block diagram of the conveying apparatus which concerns on the prior art which concerns on Embodiment 2 of this invention. It is a schematic block diagram of the whole recording device based on a prior art. It is a schematic block diagram of the conveying apparatus which concerns on a prior art. It is a schematic block diagram of the conveyance belt seen from the arrow f direction of FIG. It is sectional drawing of the conveyance belt seen from the arrow a direction of FIG. It is sectional drawing of the conveyance belt seen from the arrow b direction of FIG. It is the graph which showed the change of the surface potential just under the head when the recording paper concerning a prior art was conveyed.

Explanation of symbols

7 Recording Head 27 Upper Guide 28 Lower Guide 30 Conveying Device Frame 31 Conveying Belt 32 Conveying Roller 33 Adsorbing Roller 34 Drive Roller 35 Pressure Roller 36 Adsorbing Force Generating Unit 36a Electrode Plate 36b Grounding Plate 36c Base Layer 36d Surface Layer 38 Spring 40 Humidifying Unit 41 Water holding container 50 Arm 51 Spring 101 Recording device 107 Recording head unit 107K Black recording head 107C Cyan recording head 107M Magenta recording head 107Y Yellow recording head 121 Pressure plate 122 Feeding rotary member 123 PE sensor 124 Pressure plate spring 125 Separation pad 126 Separation Claw 130 Platen 131 Conveying Belt 132 Conveying Roller 133 Adsorbing Roller 134 Driving Roller 135 Pressure Roller 136 Adsorbing Force Generating Means 136a Plus Electrode Plate 136b My Eggplant electrode plate 136a 'Power-supplied part 136b' Power-supplied part 136c Base layer 136d Surface layer 137 Cleaning blade 138 Cleaning roller 139 Paper pressing roller support member 141 Paper discharge roller 142 Spur 143 Paper discharge tray 150 Arm 151 Spring 152 Power supply brush 153 Static elimination brush 170 Head holder 171 Cap 172 Shaft 190 Feed rotating body 191 Manual feed tray P Recording sheet

Claims (6)

In a recording apparatus provided with a recording printing means at a position opposite to a conveying means using a conveying belt that applies a voltage and attracts and conveys paper by electrostatic force,
A recording medium transporting apparatus, wherein an electrostatic force is applied so that a recording sheet surface potential is lower than a mist adsorption voltage at a recording means head position during recording.   2. The recording medium conveying apparatus according to claim 1, wherein the electrostatic force generating means is a comb electrode provided on the surface of the conveying belt.   3. A recording medium conveying apparatus according to claim 2, wherein the recording medium conveying device is constantly applied in the recording printing means passage region.   The humidifying means is provided on the recording paper between the recording means leading position and the voltage application start position so that the recording paper surface potential becomes uniform at the recording means leading position. 2. A recording medium conveying apparatus according to 1.   The recording medium conveying apparatus according to claim 1, wherein the recording printing unit is an ink jet system.   6. A recording medium conveying apparatus according to claim 5, wherein the humidifying means is an ink jet recording means.

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