JP2015105163A - Paper transportation device and image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress degradation in flatness of paper by suppressing deflection of a platen part at the time of paper sucking.SOLUTION: A paper transport device 200 includes a platen part 201 which supports paper to be transported, with a sucking hole 201a formed, being a through hole penetrating in thickness direction, a chamber 202 which is a closed space positioned below the platen part 201, acting as an air chamber for forming a negative pressure, and a suction fan which communicates with the chamber 202 and acts as a negative pressure formation part for forming a negative pressure in the chamber. The platen part 201 is divided in a plurality of portions along paper transportation direction for transporting recording paper P.

Description

  The present invention relates to a sheet conveying device used in an image forming apparatus such as an inkjet recording apparatus and a copying machine, and an image forming apparatus including the sheet conveying apparatus.

  In an inkjet recording apparatus that forms an image on a recording medium sheet by ejecting ink from the nozzles of the recording head, the sheet is conveyed directly below the recording head while maintaining the flatness of the sheet in order to ensure image quality. is important. As a paper transport device that transports paper, a plurality of suction holes are drilled in the platen plate material that supports the paper, and air is sucked from these suction holes to support the paper in a state where it is spread on a flat surface. However, what is configured to be conveyed is known.

  In the image forming apparatus equipped with the paper transport device of Patent Document 1, a plurality of platen portions in which a plurality of suction holes are formed are arranged in the paper width direction, which is a direction orthogonal to the paper transport direction, and the back surface of each platen portion. An air chamber communicating with the suction hole is provided on the side. Each of these air chambers is provided with a suction fan as a negative pressure forming unit, and by selectively driving the suction fan, the corresponding air chamber is made to have a negative pressure and the suction on the paper on the platen unit is performed individually. . Then, ink is ejected from the recording head that reciprocates in the paper width direction onto the paper supported on the platen portion, thereby forming an image.

  However, in the paper transport device of Patent Document 1, since the printing width tends to increase and the length of the platen portion in the paper transport direction tends to increase as the printing speed increases in recent years, the platen portion bends due to the suction force. easy. As a result, the flatness of the paper supported on the bent platen may be deteriorated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a sheet conveying device and an image forming apparatus capable of suppressing the bending of the platen portion during sheet suction and suppressing the deterioration of the sheet flatness. That is.

  In order to achieve the above object, the invention of claim 1 supports a sheet to be conveyed and has a platen portion formed with a suction hole which is a through-hole penetrating in the thickness direction, and a back side of the platen portion. In a paper conveying apparatus including an air chamber that forms a negative pressure in a closed space and a negative pressure forming unit that communicates with the air chamber and forms a negative pressure in the air chamber, the platen unit The sheet is divided into a plurality of sheets in the sheet conveyance direction.

  According to the present invention, it is possible to obtain a unique effect of suppressing the bending of the platen portion at the time of sheet suction and suppressing the deterioration of the flatness of the sheet.

1 is a perspective view illustrating a configuration of an ink jet recording apparatus according to an embodiment. It is a side view of the mechanism part of the inkjet recording device of this embodiment. It is a schematic sectional drawing explaining the structure of the paper conveying apparatus which concerns on this embodiment. FIG. 2 is a schematic plan view illustrating the configuration of a paper transport device according to the present embodiment. FIG. 3 is a perspective view illustrating a configuration of a platen unit in the paper conveyance device according to the first embodiment. FIG. 6 is a perspective view illustrating a configuration of a platen unit in a paper conveying apparatus according to a second embodiment. FIG. 10 is a partial plan view illustrating a partial configuration of a platen unit in a paper conveying apparatus according to a second embodiment. FIG. 10 is a schematic cross-sectional view illustrating a configuration of a platen unit in a paper conveyance device according to a third embodiment. (A) is a schematic plan view explaining the structure of the platen part in the paper conveying apparatus based on Example 4, (b) is the sectional view on the A-A 'line of (a). FIG. 10 is a schematic plan view illustrating a configuration of a platen unit in a paper conveying apparatus according to a fifth embodiment.

  Hereinafter, the configuration of an ink jet recording apparatus equipped with a paper conveying apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a configuration of an ink jet recording apparatus according to the present embodiment, and FIG. 2 is a side view of a mechanism portion of the ink jet recording apparatus according to the present embodiment. The ink jet recording apparatus shown in FIGS. 1 and 2 is an example of a serial type in which a carriage on which a recording head is mounted reciprocates in a paper width direction (hereinafter referred to as a main scanning direction) perpendicular to the paper transport direction. However, a line type in which a plurality of recording heads are arranged in the entire printing width may be used.

  The ink jet recording apparatus 100 of this embodiment shown in FIGS. 1 and 2 includes a carriage 101 that can move in the main scanning direction inside the apparatus main body. Then, a print head 103 mounted on the carriage 101 and a print mechanism 103 including an ink cartridge 102 for supplying ink to the print head 1 are stored. A paper feed cassette (or a paper feed tray) 104 on which a large number of recording sheets P can be stacked from the front side is detachably attached to the lower part of the apparatus main body. Further, it has a manual feed tray 105 that is opened to manually feed the recording paper P. The recording paper P fed from the paper feed cassette 104 or the manual feed tray 105 is taken in, and after a required image is recorded by the printing mechanism unit 103, the paper is discharged onto a paper discharge tray 106 mounted on the rear side.

  The printing mechanism 103 holds the carriage 101 slidably in the main scanning direction with a main guide rod 107 and a sub guide rod 108 which are guide members horizontally mounted on left and right side plates (not shown). In the carriage 101, a recording head 1 for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk) is arranged with a plurality of ink ejection ports (nozzles) in the main scanning direction. To do. The ink droplet is ejected in the downward direction. In addition, each ink cartridge 102 for supplying ink of each color to the recording head 1 is replaceably mounted on the carriage 101.

  The ink cartridge 102 is provided with an atmosphere port communicating with the atmosphere above, and a supply port for supplying ink to the recording head 1 below. A porous body filled with ink is included inside, and the ink supplied to the recording head 1 is maintained at a slight negative pressure by the capillary force of the porous body. Further, although the recording head 1 is used for each color, a single droplet discharge head having nozzles for discharging ink droplets of each color may be used.

  Here, the carriage 101 is slidably fitted to the main guide rod 107 on the rear side (downstream side in the paper conveyance direction) and slidable on the front guide rod 108 on the front side (upstream side in the paper conveyance direction). It is placed. In order to move and scan the carriage 101 in the main scanning direction, a timing belt 112 is stretched between a driving pulley 110 and a driven pulley 111 that are rotationally driven by a main scanning motor 109a. The timing belt 112 is fixed to the carriage 101, and the carriage 101 is reciprocally scanned by forward and reverse rotation of the main scanning motor 109a.

  On the other hand, in order to convey the recording sheet P set in the sheet feeding cassette 104 to the lower side of the recording head 1, a sheet feeding roller 113, a friction pad 114, a guide member 115, a registration roller 116, a conveyance roller 117, and a registration pressure roller. 118. The paper feed roller 113 and the friction pad 114 separate and feed the recording paper P from the paper feed cassette 104. The guide member 115 is a guide member that guides the recording paper P. The registration roller 116 is a conveyance roller that reverses and conveys the fed recording paper P. The registration pressure roller 118 presses the recording paper P against the peripheral surface of the registration roller 116, and defines the feeding angle of the recording paper P from the registration roller 116. The registration roller 116 is rotated by a sub-scanning motor 109b through a gear train.

  Then, the sheet transport device 119 according to the present embodiment, which is a sheet guide member, is used to guide the recording sheet P fed from the registration roller 116 corresponding to the movement range of the carriage 101 in the main scanning direction on the lower side of the recording head 1. Provided. A transport roller 120 and a spur 121 that are rotationally driven to send the recording paper P in the paper discharge direction are provided on the downstream side of the paper transport device 119 in the paper transport direction. Further, a paper discharge roller 123 for sending the recording paper P to the paper discharge tray 106, a spur 124, and guide members 125 and 126 for forming a paper discharge path are provided.

  During recording by the inkjet recording apparatus 100, the recording head 1 is driven in accordance with the image signal while moving the carriage 101, thereby ejecting ink onto the recording paper P that has stopped, and then recording one line. Then, after the recording paper P is conveyed by a predetermined amount, the next line is recorded. Upon receiving a recording end signal or a signal that the trailing edge of the recording paper P reaches the recording area, the recording operation is terminated and the recording paper P is discharged.

  Further, a recovery device 127 for recovering the ejection failure of the recording head 1 is arranged at a position outside the recording area on the right end side in the moving direction of the carriage 101. Each of the recovery devices 127 includes a cap unit, a suction unit, and a cleaning unit (not shown). During printing standby, the carriage 101 is moved to the recovery device 127 side, and the recording head 1 is capped by the capping unit to keep the ejection port portion wet, thereby preventing ejection failure due to ink drying. Further, by ejecting ink that is not related to recording during recording or the like, the ink viscosity of all the ejection ports is made constant and stable ejection performance is maintained.

  Further, when a discharge failure occurs, the discharge port (nozzle) of the recording head 1 is sealed by the capping unit, and bubbles and the like are sucked out from the discharge port by the suction unit through the tube. Ink, dust, etc. adhering to the ejection port surface are removed by the cleaning means, and the ejection failure is recovered. Further, the sucked ink is discharged to a waste ink reservoir (not shown) installed at the lower part of the main body and absorbed and held by an ink absorber inside the waste ink reservoir.

  FIG. 3 is a schematic cross-sectional view for explaining the configuration of the sheet conveying apparatus according to the present embodiment. A sheet conveying apparatus 200 shown in FIG. 3 includes a platen unit 201 having a plane for smoothly supporting a sheet as a recording medium immediately below the recording head 1, and a chamber 202 as an air chamber below the platen unit 201. And. The platen unit 201 includes a plurality of (two in FIG. 3) flat plate members, a first platen member 201a and a second platen member 201b in the paper conveyance direction. The first platen member 201a and the second platen member 201b are perforated so that a large number of suction holes 201c are distributed on the flat plate material on average, and air is sucked from these suction holes 201c to spread the sheet in a plane. It is configured to be able to slide while adsorbing and supporting the state. The chamber 202 includes a first chamber 202a and a second chamber 202b which are housing members that cover the lower portions of the first platen member 201a and the second platen member 201b. A first decompression chamber 202a-1 and a second decompression chamber 202b-1 are formed inside the first chamber 202a and the second chamber 202b. These decompression chambers are provided over the entire width of the sheet. The first suction fan 202a-3 and the second suction fan 202b-3 as negative pressure forming parts are provided at the bottom of each decompression chamber via the first communication chamber 202a-2 and the second communication chamber 202b-2. Are installed.

  Next, a paper transport operation in the paper transport apparatus having such a configuration will be described. When the first suction fan 202a-3 is driven, the air in the first decompression chamber 202a-1 of the first chamber 202a is forcibly exhausted to the outside through the first communication chamber 202a-2. Thereby, the inside of the 1st decompression chamber 202a-1 of the 1st chamber 202a becomes a negative pressure. As a result, air flows in from the plurality of suction holes 201c of the first platen portion 201a, passes through the first decompression chamber 202a-1, and drives the first suction fan 202a-3, thereby causing the first opening 202a on the bottom side. -4 flows to be exhausted. The sheet that is nipped and conveyed between the registration roller 301 and the registration pressure roller 302 is conveyed onto the first platen portion 201 a of the chamber 202. By driving the first suction fan 202a-3, a negative pressure is formed in the first decompression chamber 202a-1, and a suction force is applied to the sheet through the suction hole 201c of the first platen portion 201a. As a result, the sheet is attracted onto the first platen portion 201a and the flatness is maintained. In addition, since the same sheet conveying operation is performed in the second platen unit 201b and the second chamber 202b, the description thereof is omitted.

  The first suction fan 202a-3 and the second suction fan 202b-3 are controlled by PWM (Pulse Width Modulation) in order to cope with various paper sizes and types. By changing the duty value of the PWM signal supplied to the drive motor (not shown) of each suction fan, the suction force for bringing the sheet into close contact with the platen portion is changed.

  A carriage 101 on which the recording head 1 for ejecting ink is mounted is disposed above the platen unit 201. The carriage 101 is equipped with an optical sensor (not shown) for detecting the leading edge of the sheet and the width of the sheet. The carriage 101 reciprocates in the paper width direction along a main guide rod 107 attached to the main scanning stay 130. An image is formed on the paper by ejecting ink toward the paper on the platen unit 201 by the black ink recording head 1a and the color ink recording head 1b.

  FIG. 4 is a schematic plan view for explaining the configuration of the sheet conveying apparatus according to the present embodiment. As shown in FIG. 4, the platen unit in the paper transport apparatus according to the present embodiment is divided into a plurality (two in FIG. 4) in the paper transport direction. A first platen unit 201a and a second platen unit 201b disposed downstream of the first platen unit 201a in the paper conveyance direction are provided adjacent to each other. The black ink recording head 1a has a print width approximately twice that of the color ink recording head 1b, and the upstream end of the black ink recording head 1a and the color ink recording head 1b in the paper transport direction is Are consistent with each other. The recording head 1b for color ink has three colors of Y (yellow), C (cyan), and M (magenta), but the same effect can be obtained regardless of the number of colors. These recording heads are configured to form an image by adhering to a smooth recording surface of a sheet while reciprocating in the main scanning direction and flying fine droplets of ink.

Next, the operation of the sheet conveying device mounted on the image forming apparatus of the above embodiment will be described.
When an image is formed on a sheet by the image forming apparatus, a user operates an operation unit (not shown) of the main body of the image forming apparatus so that an image formation instruction signal is sent to the maintenance fish part (not shown). . The control unit sends a control signal to the printing mechanism unit 103 shown in FIG. 2 to perform image formation, and sends a control signal to the paper carrying device 200 shown in FIG. 3 to carry the paper onto the platen unit. At this time, the sheet passes through a sheet position detection sensor (not shown) disposed on the upstream side of the sheet conveying apparatus 200 from the platen unit 201. A signal when the paper is detected is sent to the control unit, and the control unit supplies PWM signals to the drive motors of the first suction fan 202a-3 and the second suction fan 202b-3 in FIG. 3 to rotate each suction fan. Drive. Then, in the 1st chamber 202a and the 2nd chamber 202b, many suction of the 1st platen part 201a and the 2nd platen part 201b is carried out by the suction action of the air of the 1st suction fan 202a-3 and the 2nd suction fan 202b-3. Air flows into the first decompression chamber 202a-1 and the second decompression chamber 202b-1 through the hole 201c. Then, when the sheet starts to move in order on the first platen unit 201a and the second platen unit 201b, the leading edge of the sheet is conveyed so as to sequentially pass through portions corresponding to a plurality of chambers on the plane of the platen unit. At this time, when the sheet closes the numerous suction holes 201 c of the platen unit 201, the decompression chamber of the chamber 202 is sealed, and the air pressure in the decompression chamber is reduced to approach the negative air pressure in the chamber 202. For this reason, the paper adsorbed on the upper surface of the platen portion 201 corresponding to the inside of the chamber 202 approaching the negative pressure air pressure is supported with high flatness. In the paper transport apparatus 200, the rear end side of the paper is sandwiched between transport rollers disposed upstream in the paper transport direction, and the rear end side is sandwiched between paper discharge rollers disposed downstream in the paper transport direction. While transporting the paper.

Example 1
Next, an example of the platen unit (hereinafter, this example is referred to as “Example 1”) in the paper conveyance device mounted on the image forming apparatus of the above embodiment will be described.
FIG. 5 is a perspective view illustrating the configuration of the platen unit in the paper conveying apparatus according to the first embodiment. The sheet conveying apparatus 200 shown in FIG. 5 includes a plurality of (two sheets in FIG. 5) first platen portions 201a and second platen portions 201b in the main scanning direction. The first platen portion 201a and the second platen portion 201b include four support portions 201d for each platen portion. These support portions 201d are members that sandwich a cylindrical flatness adjusting member 203 protruding outward from a housing (not shown) constituting the chamber. The platen part 201 is supported by sandwiching the flatness adjusting member 203 between these support parts 201d. In addition, the flatness adjusting member 203 has a configuration that can be adjusted to a three-dimensional (tilt) position. When the flatness adjusting member 203 is moved to a three-dimensional position during assembly, the flatness can be adjusted. The adjustment member 203 is fixed to a casing constituting the chamber using a jig. In addition, the installation location of the support part 201d of each platen part 201 should just be three or more places. As shown in FIG. 5, at least one portion of the support portion by the flatness adjusting member 203 is disposed on the abutting side of the first platen portion 201a and the second platen portion 201b, and the remaining two portions are adjacent to each other. It arranges at the both end position when arranging.

(Example 2)
Next, another example of the platen unit in the sheet conveying device mounted on the image forming apparatus of the above embodiment (hereinafter, this example is referred to as “Example 2”) will be described.
FIG. 6 is a perspective view illustrating the configuration of the platen unit in the paper conveying apparatus according to the second embodiment. FIG. 7 is a partial plan view illustrating a partial configuration of the platen unit in the paper conveying apparatus according to the second embodiment. In the paper conveying apparatus 200 shown in FIG. 6 and FIG. 7, each plate material is extended to the abutting side of the adjacent first platen part 201 a and the second platen part 201 b, so that a gap on the abutting side of each platen part 201 is formed. Covering. In the second embodiment, for example, three or four flatness adjusting members 204 are used when there are two platen portions 201. The flatness adjusting member 204 is sandwiched between two support portions. In the case where there are three flatness adjusting members 204, as shown in FIG. 6, the first flatness adjusting member 204 is arranged on the abutting side of the first platen portion 201a and the second platen portion 201b, thereby The platen part 201a and the second platen part 201b are supported simultaneously.

(Example 3)
Next, still another example of the platen unit in the sheet conveying device mounted in the image forming apparatus of the above embodiment (hereinafter, this example is referred to as “Example 3”) will be described.
FIG. 8 is a schematic cross-sectional view illustrating the configuration of the platen unit in the paper conveyance device according to the third embodiment. As shown in FIG. 8, in Example 3, four flatness adjusting members 204 are used. When there are four flatness adjusting members 204, one flatness adjusting member 204 is arranged on the abutting side of the first platen portion 201a and the second platen portion 201b, and the platen portions 201 are held independently of each other. .

Example 4
Next, still another example of the platen unit in the sheet conveying device mounted on the image forming apparatus of the above embodiment (hereinafter, this example is referred to as “Example 4”) will be described.
FIG. 9 is a diagram illustrating the configuration of the platen unit in the paper conveying apparatus according to the fourth embodiment. FIG. 9A is a schematic plan view, and FIG. 9B is a cross-sectional view taken along the line AA ′ of FIG. 9A. As shown in FIGS. 9 (a) and 9 (b), at least one recess 401 (for example, at the place where the first platen 201a and the second platen 201b abut when the two platen parts 201 are arranged) A notch is provided across each platen. In the recess 401, at least one suction hole 201c exists. The recess 401 is formed so as to be surrounded by a partition wall 402. By providing such a configuration, the spaces of the concave portions 401 of the platen portions that are in contact with each other communicate with each other, so that the suction of the sheet can be maintained even at the place where the platen portions are connected to each other. High flatness of the paper can be ensured. The area of the paper covering the opening of the recess 401 can be increased, and the suction from the suction hole 201c can be easily applied to the paper. In addition, the opening cross-sectional shape of the recessed part 401 does not need to be a shape which becomes long in a conveyance direction as shown in FIG. Further, the recesses 401 are alternately arranged in the main scanning direction orthogonal to the paper conveyance direction as shown in FIG. 9, but may not be such an arrangement and may be aligned with each other in the main scanning direction. Good.

(Example 5)
Next, still another example of the platen unit in the sheet conveying device mounted on the image forming apparatus of the above embodiment (hereinafter, this example is referred to as “Example 5”) will be described.
FIG. 10 is a schematic plan view illustrating the configuration of the platen unit in the paper conveyance device according to the sixth embodiment. As shown in FIG. 10, a first chamber 202a and a second chamber 202b are individually provided corresponding to the first platen portion 201a and the second platen portion 201b. In this case, there is a gap communicating with the outside on the abutting side of the first platen portion 201a and the second platen portion 201b. The fifth embodiment has a configuration in which a sealing agent 501 such as sponge or rubber is sandwiched between the gaps. Note that the sealant 501 is sandwiched in the entire range of joints between the platen portions. Thereby, when sucked by the first suction fan 202a-3 and the second suction fan 202b-3, it is possible to prevent the outside air from being sucked through the gap between the platen portions, and the suction force for sucking the recording paper P is reduced. Can be suppressed.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect 1)
A platen unit 201 that supports a sheet to be conveyed and has a suction hole 201c that is a through-hole penetrating in the thickness direction, and a closed space under the platen unit 201 that forms a negative pressure The platen unit 201 includes a chamber 202 and a suction fan as a negative pressure forming unit that communicates with the chamber 202 and forms a negative pressure in the chamber. It is divided into multiple.
According to this, as described in the above embodiment, the platen part can be more rigid than the conventional structure by subdividing the entire platen part and reducing the area of the sheet conveying surface of each platen part. As a result, the platen portion can counter the suction force caused by the negative pressure formed in the chamber by the suction fan, and the platen portion can be prevented from bending. Therefore, deterioration of the flatness of the paper supported on the platen portion can be suppressed.
(Aspect 2)
In (Aspect 1), the platen unit 201 includes flatness adjusting members 203 and 204 as tilt adjusting units that adjust the tilt of the platen unit 201. According to this, as described in Example 1 of the above embodiment, the inclinations of the platen unit 201 are matched with each other using the flatness adjusting members 203 and 204. Thereby, even if the paper is conveyed across the plurality of platen portions 201, the flatness of the paper can be ensured.
(Aspect 3)
In (Aspect 2), the flatness adjusting members 203 and 204 are constituted by shaft members. According to this, as described in Example 1, Example 2 and Example 3 of the above-described embodiment, the platen flatness adjusting members 203 and 204 are axially moved in a three-dimensional manner so that a plurality of platen portions 201 are moved. Can be matched to each other. Thereby, even if the paper is conveyed across the plurality of platen portions 201, the flatness of the paper can be ensured.
(Aspect 4)
In any one of (Aspect 1) to (Aspect 3), a concave portion 401 is formed on one side surface of the platen portion 201, and a suction hole 201c is formed in the concave portion 401. According to this, as described in Example 5 of the above embodiment, since the suction hole 201a exists in the recess 401, the area of the paper covering the opening of the recess 401 can be increased. It becomes easy to apply suction from the 201a to the sheet. By communicating the spaces of the recessed portions 401 of the platen portions that are abutted with each other, the suction of the paper can be maintained even at the place where the platen portions are joined, and the high flatness of the paper can be ensured. Can do.
(Aspect 5)
In any one of (Aspect 1) to (Aspect 4), a sealing agent 501 is provided as a sealing member that closes the gap between the connecting portions of the platen portions. According to this, as described in Example 5 of the above embodiment, air is sucked from the outside when sucked by the first suction fan 202a-3 and the second suction fan 202b-3 from the gap between the platen portions. This can prevent the decrease in suction force.
(Aspect 6)
An image forming apparatus including a sheet conveying device 119 that conveys a sheet fed from a sheet feeding device, and a printing mechanism unit 103 that is an image forming unit that ejects droplets of a recording agent on the sheet to form an image. In the inkjet recording apparatus 100, any one of (Aspect 1) to (Aspect 5) is used as the paper transport device 119. According to this, as described in the above embodiment, since it is possible to suppress the occurrence of bending of the platen portion that occurs during the suction of the paper and to improve the flatness of the paper, it is possible to land the recording agent on the target position of the paper, An image forming apparatus with high image quality and high productivity can be provided.

DESCRIPTION OF SYMBOLS 100 Inkjet recording apparatus 200 Paper conveyance apparatus 201 Platen part 201a 1st platen part 201b 2nd platen part 201c Suction hole 201d Support part 202 Chamber 202a 1st chamber 202b 2nd chamber 202a-1 1st decompression chamber 202a-2 1st communication Chamber 202a-3 First suction fan 202a-4 First opening 202b-1 Second decompression chamber 202b-2 Second communication chamber 202b-3 Second suction fan 202b-4 Second opening 203 Flatness adjusting member 204 Plane Degree adjustment member 301 Registration roller 302 Registration pressure roller 401 Concave portion 402 Partition 501 Sealant

JP 2011-056694 A

Claims (6)

A platen portion that supports a sheet to be conveyed and has a suction hole that is a through-hole penetrating in the thickness direction; a closed space under the platen portion that forms a negative pressure; and In a paper conveying device comprising a negative pressure forming unit communicating with an air chamber and forming a negative pressure in the air chamber,
The sheet transporting apparatus, wherein the platen unit is divided into a plurality of sheets in a sheet transport direction for transporting a sheet. In the paper conveyance device according to claim 1,
The sheet conveying apparatus, wherein the platen unit includes an inclination adjusting unit that adjusts an inclination of the platen unit. In the paper conveyance device according to claim 2,
The inclination adjusting unit is configured by a shaft member. In the paper conveying apparatus in any one of Claims 1-3,
A paper conveying apparatus, wherein a concave portion is formed on one side surface of the platen portion, and a suction hole is formed in the concave portion. In the paper conveying apparatus in any one of Claims 1-4,
A sheet transporting device, comprising: a sealing member that closes a gap between connecting portions of the platen portions. In an image forming apparatus comprising: a sheet conveying unit that conveys a sheet fed from a sheet feeding device; and an image forming unit that forms an image by ejecting droplets of a recording agent on the sheet.
An image forming apparatus using the sheet conveying apparatus according to claim 1 as the sheet conveying unit.

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