Image recording device

Abstract

To provide an image recording device that can be miniaturized.SOLUTION: An image recording device 100 includes: pulleys 181D and 181U spaced apart from each other in a conveyance direction; an endless belt 182 wound around the pulleys 181D and 181U, extending in the conveyance direction and conveying a medium S to be recorded in contact therewith; a recording head 190 facing the endless belt 182 in a facing direction crossing the conveyance direction; a side roller 183 coaxial with the pulley 181D; and a pinch roller 185 for pinching the medium S to be recorded together with a side roller 183. The pulley 181D is located upstream in the conveyance direction from the pulley 181U, and the pulley 181U is located downstream from the recording head 190 in the conveyance direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an image recording device. [Background technology]

[0002] Patent Document 1 describes an inkjet printer as an image recording device. In the printer, a pair of conveying rollers rotates while sandwiching a sheet of paper, sending the sheet to a printing unit located downstream in the conveying direction. In the printing unit, a head and a conveying belt face each other in a direction intersecting the conveying direction. The conveying belt receives the sheet of paper sent from the pair of conveying rollers and conveys the sheet to a position opposite the head. When the conveying belt receives the sheet from the pair of conveying rollers, the leading edge of the sheet sent from the pair of conveying rollers contacts the circumferential surface of the conveying belt, and as the sheet is further conveyed by the pair of conveying rollers, the sheet rides up on the circumferential surface of the conveying belt. When the sheet rides up on the circumferential surface of the conveying belt to a certain extent, the conveying force of the conveying belt is transmitted to the sheet, and the sheet is conveyed by the pair of conveying rollers and the conveying belt. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-104600 Summary of the Invention [Problem to be solved by the invention]

[0004] When the paper is handed over to the conveyor belt, the conveyor belt does not hold the paper therebetween, so the paper tends to change position obliquely relative to the conveying direction, making it difficult to convey the paper along the conveying direction.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image recording device in which the posture of a recording medium such as paper is less likely to change. [Means for solving the problem]

[0006] The image recording device according to the present invention includes a first pulley and a second pulley spaced apart in a transport direction, an endless belt wound around the first pulley and the second pulley, extending along the transport direction, and contacting and transporting a recording medium, a recording head facing the endless belt in an opposing direction intersecting the transport direction, a first roller coaxial with the first pulley, and a second roller for sandwiching the recording medium together with the first roller. The first pulley is located upstream of the second pulley in the transport direction. The second pulley is located downstream of the recording head in the transport direction. [Effects of the Invention]

[0007] According to the present invention, the first roller and the second roller overlap with the first pulley in terms of their positions in the transport direction, so that when the recording medium is transported by the endless belt, the recording medium is sandwiched between the first roller and the second roller, which stabilizes the posture of the recording medium when transported, allowing the recording medium to be transported in the transport direction. [Brief explanation of the drawings]

[0008] [Figure 1] 1A and 1B are schematic diagrams showing an image recording device 100, in which (A) is a perspective view showing the appearance of the image recording device 100, and (B) is a cross-sectional view of the longitudinal section along the dashed double-dashed line Ib-Ib in FIG. 1A as viewed from the right. [Figure 2] FIG. 2 is a perspective view of the belt conveyance mechanism 180 shown in FIG. [Figure 3] FIG. 1 is a block diagram of an image recording device 100. [Figure 4] 1A is a schematic diagram of the belt conveyance mechanism 180 as seen from the rear, and FIG. 1B is a schematic diagram of the belt conveyance mechanism 180 as seen from the front. [Figure 5] FIG. 10 is a schematic diagram showing the configuration of a belt conveyance mechanism 400 according to a first modified example. [Figure 6] FIG. 10 is a schematic diagram showing a main part of an image recording device 100 according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] An image recording device 100 according to an embodiment of the present invention will be described below. Note that the embodiment described below is merely an example of the present invention, and it goes without saying that the embodiment can be modified as appropriate without departing from the spirit and scope of the present invention.

[0010] [Term definition] In the following description, the direction of an arrow is expressed as the progression from the starting point to the end point, and the movement on the line connecting the starting point and end point of the arrow is expressed as the direction.

[0011] The up-down direction 7 is defined based on the state in which the image recording device 100 is installed and ready for use (the state shown in Figure 1), the front-to-back direction 8 is defined with the side where the discharge outlet 120 is located as the front side (front surface 11F), and the left-to-right direction 9 is defined when the image recording device 100 is viewed from the front side (front surface 11F).

[0012] [External Configuration of Image Recording Device 100] In FIG. 1, the image recording device 100 is used while placed on a table, floor, or rack, and records an image on a recording medium S using an inkjet recording method. In FIG. 1(B), the recording medium S is roll paper forming a roll body 300. Roll paper is a long continuous paper wound into a roll, and includes label roll paper. Label roll paper has label paper, on which images are recorded, attached at intervals to a long backing sheet. Note that the roll paper may also be continuous paper wound into a roll. The recording medium S may also be fanfold paper.

[0013] In FIG. 1(A), the image recording device 100 includes a housing 110 having a generally rectangular parallelepiped shape. The housing 110 separates an internal space 11A (see FIG. 1(B)) of the housing 110 from the outside. An ejection opening 120 is located in the upper right portion of the front surface 11F of the housing 110. The ejection opening 120 is a rectangular hole that is elongated in the left-right direction 9. A recording medium S on which an image has been recorded is ejected from the ejection opening 120.

[0014] The front surface 11F is also provided with an operation panel 130 and a front cover 141. The operation panel 130 is used by the user to input information to operate the image recording device 100 and to confirm various settings. By opening and closing the front cover 141, a tank 150 (see FIG. 1(B)) and the like located in the internal space 11A are exposed or hidden.

[0015] [Internal configuration of image recording device 100] 1(B), the image recording device 100 includes, in an internal space 11A, a holder 160, a tensioner 170, a skew prevention guide 172, a belt conveyance mechanism 180, and a recording head 190. In FIG.

[0016] [Holder 160] 1(B), the holder 160 is located near the lower rear corner of the internal space 11A and can accommodate the roll body 300. The holder 160 rotates in the circumferential direction of a rotation axis along the left-right direction 9 under the control of the controller 200 by power generated by a motor (not shown).

[0017] When the roll 300 is attached to the holder 160, the axis of the roll 300 coincides with the rotation axis of the holder 160. The left-right center of each label paper on the recording medium S is located along the reference plane C (see FIG. 4). The reference plane C is sometimes called the paper feed center and is an imaginary plane parallel to the up-down direction 7 and the left-right direction 9. The roll 300 rotates in conjunction with the rotation of the holder 160. As the holder 160 and other components rotate, the recording medium S is pulled upward from the rear end of the roll 300 and sent to the tensioner 170. When the recording medium S is pulled out from the roll 300, the holder 160 rotates counterclockwise when viewed from the right.

[0018] An openable right cover 142 is provided on the right surface 11R (see FIG. 1A) of the housing 110. By opening and closing the right cover 142, the holder 160 and the like in the internal space 11A are exposed to the outside or shielded from the outside.

[0019] [Tensioner 170] 1(B), the tensioner 170 is located in the internal space 11A near the rear surface 11B and toward the upper surface 11U. The tensioner 170 is located almost directly above the holder 160. A partition wall (not shown) is provided between the tensioner 170 and the holder 160. The partition wall prevents ink droplets falling from the recording head 190 from adhering to the roll body 300.

[0020] The tensioner 170 has a curved portion 171. The curved portion 171 forms a curved surface that bulges out toward the upper rear corner of the housing 110. The left-right length of the curved portion 171 is longer than the left-right length of the roll body 300. The curved portion 171 has a shape that is line-symmetrical with respect to a reference plane C (see FIG. 4). The upper end of the curved portion 171 is at approximately the same vertical position as the upper end surface 1821 of the endless belt 182 in the vertical direction 7.

[0021] The recording medium S, pulled upward from the roll body 300, is wound around the curved portion 171. The recording medium S abuts against the rear end of the curved portion 171 or slightly below it, and extends along the curved portion 171 in the conveying direction 8A. In this embodiment, the conveying direction 8A is forward. The front-to-rear direction 8 is an example of the conveying direction. The curved portion 171 is biased rearward by a spring or the like. The tensioner 170 applies tension to the recording medium S so that the recording medium S does not become loose.

[0022] [Skewing prevention guide 172] 1(B), the skew prevention guide 172 is located between the tensioner 170 and the belt conveyance mechanism 180 in the front-rear direction 8. The skew prevention guide 172 abuts against both left and right ends of the recording medium S with the left-right center of the recording medium S aligned with the reference plane C. The skew prevention guide 172 guides the recording medium S toward the belt conveyance mechanism 180 in front so that both ends are parallel to the conveyance direction 8A.

[0023] [Belt conveying mechanism 180] 1(B), the belt conveying mechanism 180 is located between the skew prevention guide 172 and the discharge port 120 in the front-rear direction 8. In FIG. 2, the belt conveying mechanism 180 includes pulleys 181U and 181D, an endless belt 182, a plurality of side rollers 183, a plurality of side rollers 184, a pinch roller 185, a plurality of contact members 186, and an adsorption platen 187. As shown in FIG. 3, the belt conveying mechanism 180 further includes a power applying mechanism 188 and a pump 189.

[0024] [Pulley 181U, 181D] 1(B), pulley 181U is an example of a first pulley and is located forward of skew prevention guide 172. A shaft 1811 extends straight to the left and right from a shaft hole of pulley 181U, as shown in FIG. 4(A). The right and left ends of shaft 1811 are supported by bearings 1812 and 1813, and shaft 1811 is rotatable in the circumferential direction of rotation axis A1 that is parallel to the left-right direction 9.

[0025] In Fig. 1(B), pulley 181D is an example of a second pulley, and is located in front of pulley 181U and behind discharge port 120. That is, pulleys 181U and 181D are spaced apart from each other in the front-rear direction 8 (i.e., the conveying direction). As shown in Fig. 4(B), a shaft 1814 extends straight to the left and right from a shaft hole of pulley 181D. The right and left ends of shaft 1814 are supported by bearings 1815 and 1816.

[0026] As shown in Fig. 3, power generated by a power applying mechanism 188 is transmitted to the pulley 181D via a shaft 1814. The pulley 181D is rotatable in the circumferential direction of a rotation axis A2 that is parallel to the rotation axis A1. In Fig. 1(B), when the recording medium S is transported in the transport direction 8A, the pulley 181D rotates counterclockwise as viewed from the right. Hereinafter, the counterclockwise rotation of the pulley 181D, the holder 160, and the roll body 300 will also be referred to as "normal rotation."

[0027] In Figure 4, the pulleys 181U and 181D have engagement portions 1817 and 1818 with which the endless belt 182 engages. The outer diameter of the engagement portion 1818 is larger than the outer diameter of the engagement portion 1817. The left and right widths of the engagement portions 1817 and 1818 are the same and are narrower than the left and right width of the roll body 300. The left and right centers of the engagement portions 1817 and 1818 are aligned along the reference plane C. The upper end positions of the engagement portions 1817 and 1818 are the same in the up-down direction 7.

[0028] [Endless Belt 182] In FIG. 2, endless belt 182 is wound around pulleys 181U and 181D and engages with engagement portions 1817 and 1818 as shown in FIG. 4. Endless belt 182 has an upper end surface 1821. Upper end surface 1821 extends in the front-rear direction 8 and the left-right direction 9 and has a rectangular shape that is elongated in the front-rear direction 8 in a plan view. As pulley 181D rotates forward, upper end surface 1821 moves along conveyance direction 8A between the upper ends of engagement portions 1817 and 1818. Hereinafter, as shown in FIG. 4, the distances in the up-down direction 7 between upper end surface 1821 and rotation axes A1 and A2 will be referred to as distance r1 and distance r2, respectively.

[0029] [Side Rollers 183, 184] 4, each of the side rollers 183, 184 is a rubber roller or the like, in which a roller core is covered with an elastic material such as rubber. In this embodiment, the multiple side rollers 183 are an example of first rollers, and are two side rollers 183L, 183R. The multiple side rollers 184 are an example of third rollers, and are two side rollers 184L, 184R.

[0030] In FIG. 4A, side rollers 183L and 183R are located to the left and right of pulley 181U, respectively, and are attached to shaft 1811. The rotation axis of each side roller 183 coincides with rotation axis A1. The outer diameter φ3 of each side roller 183 is the same as each other. The outer diameter φ3 is slightly smaller than or equal to 2 × distance r1.

[0031] In FIG. 4(B), side rollers 184L and 184R are located to the left and right of pulley 181D, respectively, and are attached to shaft 1814. The rotation axis of each side roller 184 coincides with rotation axis A2. The outer diameter φ4 of each side roller 184 is the same as each other. The outer diameter φ4 is slightly larger than 2 × distance r2 or is equal to 2 × distance r2.

[0032] Side rollers 183L and 183R have a shape that is symmetrical about reference plane C. Side rollers 184L and 184R have a shape that is symmetrical about reference plane C. The distance in the left-right direction 9 between the left end of side roller 183L and the right end of side roller 183R is the same as the distance in the left-right direction 9 between the left end of side roller 183L and the right end of side roller 183R, and is slightly longer than the length in the left-right direction 9 of roll body 300 (see FIG. 1(B)).

[0033] [Pinch Roller 185] 4(A), pinch roller 185 is an example of a second roller, such as a rubber roller. Shaft 1851 protrudes to the right and left from the right and left ends of pinch roller 185. The right and left ends of shaft 1851 are supported by bearings 1852 and 1853. Pinch roller 185 is rotatable in the circumferential direction of rotation axis A3, which is parallel to rotation axis A1.

[0034] Pinch roller 185 extends in the left-right direction 9 above pulley 181U and each side roller 183. Pinch roller 185 is located such that rotation axis A3 is spaced upward from rotation axis A1 and the front-rear and left-right positions of rotation axis A3 are the same as those of rotation axis A1. The distance between the left and right ends of pinch roller 185 is the same as distance d1.

[0035] The pinch roller 185 has a different outer diameter in the left-right direction 9. The outer diameter of both end portions (portions facing the side rollers 183L, 183R) of the pinch roller 185 is larger than the central portion (portion facing the endless belt 182). When both end portions of the pinch roller 185 are in contact with the side rollers 183L, 183R, the outer diameter of the central portion of the pinch roller 185 is determined so as to be out of contact with the endless belt 182. Therefore, the pinch roller 185 is spaced apart from the endless belt 182. Hereinafter, the contact portion between each side roller 183 and the pinch roller 185 will also be referred to as an upstream nip.

[0036] [Abutment member 186] The contact members 186 are spur-shaped. The multiple contact members 186 are supported by holders 1861 so as to be rotatable in the circumferential direction of a rotation axis parallel to the left-right direction 9. The rotation axis of each contact member 186 is located above the rotation axis A2. In the front-rear direction 8, the rotation axis of each contact member 186 is at the same position as the rotation axis A2.

[0037] The multiple contact members 186 are aligned in a row at intervals in the left-right direction 9. In this embodiment, five contact members 186 are provided. The two left contact members 186 are positioned above the side roller 184L and are in contact with the side roller 184L. The two right contact members 186 are positioned above the side roller 184R and are in contact with the side roller 184R. The central contact member 186 is positioned above the endless belt 182 and is in contact with the endless belt 182. Each contact member 186 rotates in response to the rotation of the endless belt 182 and the side rollers 183L and 183R. Hereinafter, the contact portion between each side roller 184 and the endless belt 182 and the contact member 186 is also referred to as a downstream nip.

[0038] [Adsorption Platen 187] 2, the attraction platen 187 is located between each side roller 183 and each side roller 184 in the front-rear direction 8. The attraction platen 187 has a left side portion 187L and a right side portion 187R. The left side portion 187L and the right side portion 187R are located to the left and right of the endless belt 182, respectively.

[0039] 2 and 3, the left side portion 187L has a bottom wall 1871, a plurality of rear walls 1872, and a plurality of partition walls 1873. In this embodiment, the number of rear walls 1872 is six and the number of partition walls 1873 is seven, but in FIG. 2, only three partition walls are given the reference symbol "1873" and only two rear walls are given the reference symbol "1872." In FIG. 3, some of the rear walls 1872 and partition walls 1873 are not shown.

[0040] As shown in FIG. 3, the bottom wall 1871 has a rectangular shape in a plan view from above, and extends in the front-rear direction 8 and the left-right direction 9. The bottom wall 1871 is located below the upper end surface 1821 in the up-down direction 7, and to the left of the upper end surface 1821 in the left-right direction 9. The front end of the bottom wall 1871 is located slightly rearward from the side roller 184L (see FIG. 2). The rear end of the bottom wall 1871 is located slightly forward from the side roller 183L.

[0041] 2 and 3, each rear wall 1872 extends upward from the rear end of the bottom wall 1871 and expands in the vertical direction 7 and the left-right direction 9. The vertical position of the upper end of the rear wall 1872 is lower than the vertical position of the upper end surface 1821 over the entire area in the left-right direction 9. Note that the position of the upper end of the rear wall 1872 in the vertical direction 7 may be the same as the vertical position of the upper end surface 1821.

[0042] Each partition wall 1873 extends in the up-down direction 7 and the front-rear direction 8, and has a flat plate shape that is thin in the left-right direction 9 and long in the front-rear direction 8. Each partition wall 1873 extends upward from a different position on the bottom wall 1871 in the left-right direction 9. The position of the upper end surface of each partition wall 1873 in the up-down direction 7 is generally the same as the position of the upper end surface 1821 in the up-down direction 7 over the entire area in the front-rear direction 8. The upper end surface of each partition wall 1873, together with the upper end surface 1821, on both the left and right sides of the upper end surface 1821 of the endless belt 182, forms a conveying surface. In other words, in this embodiment, the conveying surface includes the upper end surface of each partition wall 1873 and the upper end surface 1821. Each partition wall 1873 extends rearward from the front end of the bottom wall 1871 to reach the rear wall 1872. The coefficient of friction of the upper end surface of each partition 1873 is smaller than the coefficient of friction of the upper end surface 1821 .

[0043] Two partition walls 1873 adjacent to each other in the left-right direction 9 form air flow paths 1874 together with the bottom wall 1871 and the rear wall 1872. When the recording medium S is not supported by the suction platen 187, each of the flow paths 1874 is open to the front and upward.

[0044] In the bottom wall 1871, near the rear end of each flow path 1874, an intake port 1875 that opens upward is formed.

[0045] The right side portion 187R and the left side portion 187L have symmetrical shapes with respect to the reference plane C. In each drawing, the same reference symbols are used for the configuration of the right side portion 187R that corresponds to the configuration of the left side portion 187L. Since the configurations with the same reference symbols are similar except for being symmetrical with respect to the reference plane C, a detailed description of the configuration of the right side portion 187R will be omitted.

[0046] [Powering mechanism 188, Pump 189] As shown in FIG. 3, the power applying mechanism 188 has a motor, gears, and the like, and is controlled by the controller 200 to generate power for rotating the pulley 181D and transmit it to the shaft 1814.

[0047] The pump 189 communicates with each suction port 1875 via a pipe 1891 , and is controlled by the controller 200 to suck air from each flow path 1874 through each suction port 1875 .

[0048] [Recording head 190] As shown in FIG. 1B, the recording head 190 is a line head and faces the endless belt 182 in a facing direction that intersects with the transport direction. In this embodiment, the facing direction is the up-down direction 7. The recording head 190 is located above the upper end surface 1821 in the up-down direction 7 and is positioned so as to cross the suction platen 187 from side to side. The recording head 190 is located between the pulley 181U and the pulley 181D in the front-rear direction 8. The pulley 181U is located upstream of the recording head 190 in the transport direction, and the pulley 181D is located downstream of the recording head 190 in the transport direction.

[0049] On the underside of the recording head 190, a plurality of nozzles 192 are positioned in a row in the left-right direction 9. The recording head 190 ejects ink droplets from the plurality of nozzles 192 under the control of a controller 200. Note that only one nozzle 192 is shown in FIG. 1. Alternatively, on the underside of the recording head 190, the plurality of nozzles 192 may be aligned in two or more rows spaced apart in the front-rear direction 8.

[0050] The tank 150 stores ink. The ink is a liquid containing pigments and the like. The ink has a viscosity suitable for uniformly dispersing the pigments. The pigments determine the color of the ink. The ink is supplied from the tank 150 to the recording head 190 through a tube (not shown).

[0051] [Controller 200] The controller 200 includes a CPU, a ROM, a RAM, an EEPROM, and an ASIC, which are interconnected by an internal bus or the like, and controls each part of the image recording device 100 .

[0052] [Operation of image recording device 100] 1(B), the worker sets the roll 300 in the image recording device 100. After attaching the roll 300 to the holder 160, the worker pulls out the leading edge of the recording medium S from the roll 300 and winds the recording medium S around the curved portion 171 of the tensioner 170. The worker then passes the leading edge of the recording medium S through the skew prevention guide 172 and brings the skew prevention guide 172 into contact with both left and right ends of the recording medium S. The worker then abuts or clamps the leading edge of the recording medium S against the upstream nip of the belt conveyance mechanism 180.

[0053] After the setting of the roll body 300 is completed, in response to an input from the operator, the controller 200 outputs a control signal to the pump 189 to drive the pump 189. As a result, ambient air is sucked in through each suction port 1875 of the suction platen 187.

[0054] Next, the controller 200 executes a cueing process. In the cueing process, the controller 200 outputs a control signal to each motor to rotate the holder 160 and the pulley 181D forward and backward at a predetermined timing. As a result, the leading edge of the recording medium S is moved to a position directly below the nozzle 192 on the upper end surface 1821.

[0055] The controller 200 executes image recording control when it receives print data indicating an image to be recorded on the recording medium S from an information processing device (e.g., a PC) that can communicate with the image recording device 100. In the image recording control, the controller 200 outputs control signals to each motor to rotate the holder 160 and the pulley 181D forward to transport the recording medium S in the transport direction 8A, while causing ink to be ejected from each nozzle 192 of the recording head 190 based on the print data. The ink ejected from each nozzle 192 adheres to the recording medium S, thereby recording an image according to the print data. The recording medium S on which the image has been recorded is discharged from the discharge port 120 of the housing 110.

[0056] [Operation and effect of image recording device 100] According to the image recording device 100, the side rollers 183 and pinch rollers 185 overlap with the pulleys 181U and the endless belt 182 in terms of their positions in the front-to-rear direction 8. Therefore, when the recording medium S is frictionally transported by the endless belt 182, it is sandwiched between the side rollers 183 and the pinch rollers 185. This stabilizes the posture of the recording medium S when it is transported by the endless belt 182, and allows it to be transported along the transport direction 8A of the recording medium S.

[0057] According to the image recording device 100, each side roller 183 is coaxial with the pulley 181U and nip-conveys the recording medium S together with the pinch roller 185 arranged above each side roller 183. Therefore, in the conveyance direction 8A, it is not necessary to provide a pair of conveyance rollers for the recording medium S between the tensioner 170 and the belt conveyance mechanism 180. Furthermore, each side roller 183 and the pinch roller 185 overlaps with the pulley 181U in terms of their positions in the front-rear direction 8. Therefore, the front-rear dimension of the image recording device 100 can be reduced.

[0058] Furthermore, pulley 181U is located upstream of recording head 190 in the transport direction 8A, and pulley 181D is located downstream of recording head 190 in the transport direction 8A. This allows endless belt 182 to be positioned from upstream to downstream of recording head 190 in the transport direction 8A, allowing the recording medium S to pass reliably below recording head 190.

[0059] According to image recording device 100, each side roller 184 is coaxial with pulley 181D and nip-transports recording medium S together with contact members 186 arranged above each side roller 184 and pulley 181D. Each side roller 184 and contact member 186 overlaps with pulley 181D in terms of position in the front-rear direction 8. This allows the front-rear dimension of image recording device 100 to be reduced.

[0060] According to the image recording device 100, the power generated by the power applying mechanism 188 is transmitted to the shaft 1814 of the pulley 181D, and is then transmitted to the pulley 181U through the pulley 181D and the endless belt 182. This power is also transmitted to the side roller 183 that is coaxial with the pulley 181U. This allows the pulleys 181U and 181D and the side rollers 183 and 184 to rotate with power from a common power source, and as a result, the image recording device 100 can be made smaller.

[0061] In the cueing process and image recording control, the power for driving pulley 181D is generated by power applying mechanism 188. Furthermore, endless belt 182 rotates when pulley 181D is driven, and the power generated by power applying mechanism 188 is transmitted to pulley 181U through endless belt 182. This power is also transmitted to side roller 183 which is coaxial with pulley 181U.

[0062] When the recording medium S passes through the upstream nip, it is conveyed in the conveying direction 8A by nip conveyance using the side rollers 183 and pinch roller 185 and frictional conveyance using the endless belt 182 (see FIG. 4A). At this time, greater pressure is applied to the outer portions on both sides of the recording medium S than to the inner portion near the reference plane C. Here, the inner portions are the portions of the recording medium S that contact the endless belt 182, and the outer portions are the portions of the recording medium S that contact the side rollers 183 and pinch roller 185. In other words, the conveying force of the endless belt 182 that conveys the recording medium S in the conveying direction 8A is smaller than the conveying force of the side rollers 183 and pinch roller 185. Therefore, even if a moment in the circumferential direction in the up-down direction 7 is applied to the recording medium S, the recording medium S is unlikely to rotate. In other words, the recording medium S is unlikely to skew on the upper end surface 1821.

[0063] Furthermore, the endless belt 182 does not affect the accuracy of nip conveyance because it is not in contact with the pinch roller 185. That is, the conveyance force of each side roller 183 and the pinch roller 185 is transmitted to the recording medium S efficiently.

[0064] After being sent out from the upstream nip in the conveying direction 8A, the recording medium S is conveyed in the conveying direction 8A while contacting the upper end surface 1821 and the upper end surfaces of the partition walls 1873 (see FIG. 2). In other words, the recording medium S is conveyed in the conveying direction 8A while blocking the upper ends of the flow paths 1874. At this time, air in each flow path 1874 is sucked through each suction port 1875 by driving the pump 189. Therefore, an airflow in the opposite direction to the conveying direction 8A is generated in each flow path 1874. As a result, the air pressure in each flow path 1874 is lower than the air pressure above the recording medium S, so that the recording medium S is adsorbed to the upper end surfaces of the partition walls 1873. In other words, the upper end surfaces of the partition walls 1873 are an example of an adsorption surface. The left side portion 187L, the right side portion 187R, and the pump 189 are an example of an adsorption mechanism that generates an adsorption force for adsorbing the recording medium S to the upper end surface 1821. Since the upper end surface of each partition wall 1873 has a smaller coefficient of friction than the upper end surface 1821, the recording medium S slides along the upper end surface of each partition wall 1873 in the conveyance direction 8A.

[0065] The recording medium S is conveyed in the conveying direction 8A while contacting the upper end surface 1821 and the upper end surfaces of the partition walls 1873, and then sent into the downstream nip. When passing through the downstream nip, the recording medium S is conveyed in the conveying direction 8A by nip conveyance using the side rollers 184, the endless belt 182, and a plurality of contact members 186 (see FIG. 4(B)).

[0066] As is clear from the above, outer diameter φ3≦distance r1×2, outer diameter φ4≧distance r2×2, and distance r2>distance r1. Furthermore, each side roller 183 and pulley 181U and each side roller 184 and pulley 181D rotate by power from the same power applying mechanism 188. Therefore, the peripheral speed of each side roller 183 (speed in the rotation direction of the roller surface) is slower than the peripheral speed of each side roller 184 (speed in the rotation direction of the roller surface). As a result, tension is applied to the recording medium S in the portion between the upstream nip and the downstream nip.

[0067] As described above, the recording medium S is in close contact with the upper end surface 1821 and the upper end surfaces of the partition walls 1873, and tension is applied to the recording medium S in the transport direction 8A between the upstream nip and the downstream nip, so that variation in the vertical distance between the recording medium S and each nozzle 192 lined up on the left and right of the recording head 190 can be suppressed.

[0068] [First Modification of Image Recording Device 100] The image recording device 100 of the embodiment is equipped with a belt conveying mechanism 180 in which the left-right center of the label paper is positioned at the same position as the center in the left-right direction 9 of the label paper conveying area in the belt conveying mechanism 180. In the belt conveying mechanism 180, the pulleys 181U, 181D and the endless belt 182 are laid out in the center part of the suction platen 187 in the left-right direction 9, and the left-right center of each label paper on the recording medium S is aligned with a reference plane C (see FIG. 4).

[0069] However, instead of the belt transport mechanism 180, the image recording device 100 may be provided with a belt transport mechanism 400, as shown in FIG. 5, with which the left end of the recording medium S comes into contact on the left side in the left-right direction 9.

[0070] 2 etc., the belt conveyance mechanism 400 differs in that the pulleys 181U, 181D and the endless belt 182 are positioned to the left of the center of the attraction platen 187 in the left-right direction 9. Therefore, the left-right length of the side roller 183L is shorter than the left-right length of the side roller 183R. The left-right length of the side roller 184L is shorter than the left-right length of the side roller 184R. In the attraction platen 187, the left-right width of the left side portion 187L is narrower than the left-right width of the right side portion 187R.

[0071] The belt conveying mechanism 400 differs from the belt conveying mechanism 180 in that it further includes a guide member 501 on the left side 187L of the vacuum platen 187. The guide member 501 is made of a resin material or the like, and is either integral with or separate from the vacuum platen 187. The guide member 501 protrudes upward from a position on the left side 187L to the left of the partition wall 1873 at the left end. The right side surface of the guide member 501 forms a guide surface 502.

[0072] The guide surface 502 is a rectangular surface that is parallel to the up-down direction 7 and the front-rear direction 8 and is elongated in the front-rear direction 8. The lower end of the guide surface 502 is located at the same level as the upper end surface 1821 or slightly below the upper end surface 1821 in the up-down direction 7. The upper end of the guide surface 502 is located above the upper end surface 1821 in the up-down direction 7. In other words, the guide surface 502 extends along the conveying direction (in this embodiment, the front-rear direction 8) and is perpendicular to the axial direction (in this embodiment, the left-right direction 9) along which the rotation axes A1 and A2 (see FIG. 4) extend.

[0073] According to the above configuration, the recording medium S is sent out from the upstream nip in the conveying direction 8A, and then is frictionally conveyed by the upper end surfaces 1821 while being attracted to the partition walls 1873. At this time, the left end of the recording medium S is abutted against the guide surface 502 by the nip conveyance between the side roller 183L and the pinch roller 185 and the nip conveyance between the side roller 183R and the pinch roller 185.

[0074] [Second Modification of Image Recording Device 100] In the first modified example, the recording head 190 faces the upper end surface 1821 of the endless belt 182 in the vertical direction 7. However, this is not limiting, and the recording head 190 does not have to face the upper end surface 1821 of the endless belt 182 in the vertical direction 7. In detail, the left edge position of the upper end surface 1821 may be to the right of the right edge position of the recording head 190, as shown in FIG. 6. In FIG. 6, the outline of the recording head 190 is shown by a dashed line in a plan view.

[0075] [Other variations] In the embodiment, the outer diameter of the pinch roller 185 differs depending on the left and right position, but this is not limiting, and the outer diameter of the pinch roller 185 may be constant at the left and right positions.

[0076] In the embodiment, each of the contact members 186 is a spur. However, the present invention is not limited to this, and each of the contact members 186 may be a guide instead of a rotating body such as a spur.

[0077] In the embodiment, the vacuum platen 187 generates an airflow in the flow path 1874 to lower the air pressure in the flow path 1874, thereby vacuuming the recording medium S to the upper end surface of the partition wall 1873. However, this is not limited to this, and the vacuum platen 187 may suck the recording medium S through suction holes provided in the flat vacuum platen, bringing it into close contact with the vacuum platen. Alternatively, the vacuum platen 187 may electrostatically vacuum the recording medium S by charging the vacuum platen body.

[0078] The endless belt 182 may also be a so-called suction belt.

[0079] In the embodiment, the recording head 190 uses an inkjet method to record an image on the recording medium S. However, the present invention is not limited to this, and the recording head 190 may use an electrophotographic method or a thermal transfer method. [Explanation of symbols]

[0080] 100...Image recording device 110…Housing 160...Holder 170...Tensioner 180,400...Belt conveyor mechanism 181D, 181U...pulley 182...endless belt 1821…Top end surface 183, 183L, 183R, 184, 184L, 184R...Side rollers 185...Pinch roller 186...Abutment member 187...Adsorption platen 188...Powering mechanism 189...Pump 190...recording head 192...Nozzle 200...Controller 300...Roll body 501...Guide member 502...Guide surface

Claims

1. a first pulley and a second pulley spaced apart in a conveying direction; an endless belt wound around the first pulley and the second pulley, extending along the conveyance direction, and contacting the recording medium to convey the recording medium; a recording head facing a conveyance surface including the endless belt in an opposing direction intersecting the conveyance direction; a first roller coaxial with the first pulley; a second roller for sandwiching the recording medium together with the first roller; a third roller coaxial with the second pulley; a contact member that rotates together with the third roller while sandwiching the recording medium, the first pulley is located upstream of the second pulley in the conveying direction, the second pulley is located downstream of the recording head in the transport direction, an outer diameter of the third roller is equal to or greater than an outer diameter of the endless belt when wound around the second pulley; The peripheral speed of the first roller is slower than the peripheral speed of the third roller.

2. the first rollers are located on both sides of the endless belt in the axial direction of the first pulley, 2. The image recording device according to claim 1, wherein the outer diameter of each of the first rollers positioned on both sides of the endless belt is equal to or smaller than the outer diameter of the endless belt when wound around the first pulley.

3. 3. The image recording apparatus according to claim 2, wherein the second roller is not in contact with the endless belt.

4. a power applying mechanism that applies power to either the second pulley or the third roller, 4. The image recording apparatus according to claim 1, wherein the endless belt transmits the power given by the power giving mechanism to the first roller.

5. 5. The image recording device according to claim 1, wherein the conveying force of the endless belt that conveys the recording medium in the conveying direction is smaller than the conveying force of the first roller and the second roller that convey the recording medium in the conveying direction.

6. 6. The image recording apparatus according to claim 1, wherein the first pulley is located upstream of the recording head in the transport direction.

7. the opposing direction intersects with the axial direction of the first pulley, 7. The image recording device according to claim 2, further comprising an adsorption platen having an adsorption surface that forms the conveying surface alongside the endless belt in the axial direction of the first pulley and faces the recording head in the opposing direction of the endless belt, and an adsorption mechanism that generates an adsorption force for adsorbing the recording medium to the adsorption surface.

8. 8. The image recording apparatus according to claim 1, wherein the recording head faces the endless belt in the facing direction.

Images