An ink-jet recording apparatus is provided. The ink-jet recording apparatus includes: a plurality of rollers that convey a sheet in a conveyance direction; a platen; a recording unit; a plurality of first ribs provided in the platen; and a plurality of second ribs provided between the first ribs and the rollers in the conveyance direction. The plurality of rollers, the plurality of first ribs, and the plurality of second ribs are each disposed in a position where at least parts of them overlap in the width direction, and a length in the width direction of each of the supporting surfaces of the plurality of second ribs is longer than that in the width direction of each of the supporting surfaces of the plurality of first ribs, and is shorter than that in the width direction of an abutting surface on the sheet in each of the plurality of rollers.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese Patent Application No. 2016-016670 filed on Jan. 29, 2016, the disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to an ink-jet recording apparatus that records an image on a sheet by discharging ink droplets from nozzles.

DESCRIPTION OF THE RELATED ART

In an ink-jet recording apparatus, a sheet being conveyed along a conveyance path formed inside the apparatus sometimes ends up floating up from a platen supporting said sheet. When floating-up of the sheet occurs at a position facing a nozzle, a spacing between the sheet and the nozzle ends up changing, and there is a risk that an effect ends up being exerted on image quality of an image recorded on the sheet.

In order to solve such a problem, conventionally, an ink-jet recording apparatus in which high ribs and low ribs that extend along a conveyance direction of the sheet are disposed alternately along a width direction, is known. In a publicly known ink-jet recording apparatus, when an ink droplet discharged from a nozzle adheres to a sheet supported by high ribs and low ribs, said sheet attains a waved state along the width direction. As a result, warping upward of the sheet is reduced, hence a change in spacing between the sheet and the nozzle can be reduced.

SUMMARY

However, according to findings of the inventors, in the above-mentioned ink-jet recording apparatus, the following problem occurs. Said ink-jet recording apparatus includes a roller for conveying the sheet, downstream in the conveyance direction of the platen. A plurality of said rollers are provided along the width direction, at the same positions as the ribs, in the width direction. As a result, a waveform shape of the sheet formed by the ribs is reliably maintained in an entire region of the platen.

A length in the width direction of each of the rollers is longer than a length in the width direction of each of the ribs. Therefore, when the sheet that has the waveform shape formed therein by being supported by the ribs on the platen enters the roller, a wavelength of the waveform shape of the sheet in a portion that has entered the roller in the sheet, suddenly changes. As a result, there is a risk that the waveform shape of not only the portion that has entered the roller in the sheet, but also a portion supported by the ribs in the sheet, is lost. If the waveform shape of the portion supported by the ribs in the sheet is lost, there is a risk of an effect being exerted on the image recorded on the sheet.

The present teaching was made in view of the above-described problem, and has an object of providing an ink-jet recording apparatus capable of favorably maintaining a waveform shape of a sheet on a platen.

According to an aspect of the present teaching, there is provided an ink-jet recording apparatus configured to discharge ink droplets onto a sheet, including:

a plurality of rollers configured to convey the sheet in a conveyance direction, the plurality of rollers being disposed so that each of two adjacent rollers of the plurality of the rollers have a spacing therebetween in a width direction orthogonal to the conveyance direction;

a platen disposed more upstream in the conveyance direction than the plurality of rollers;

a recording unit disposed above the platen and configured to discharge the ink droplets from a plurality of nozzles toward the platen;

a plurality of first ribs provided in the platen, disposed so that each of two adjacent first ribs of the plurality of the first ribs have a spacing therebetween in the width direction, and each having a supporting surface for supporting the sheet; and a plurality of second ribs provided between the plurality of first ribs and the plurality of rollers in the conveyance direction, respectively, disposed so that each of two adjacent second ribs of the plurality of the second ribs have a spacing therebetween in the width direction, and each having a supporting surface for supporting the sheet,

wherein at least parts of the plurality of rollers, the plurality of first ribs, and the plurality of second ribs overlap in the width direction, and

wherein a length in the width direction of each of the supporting surfaces of the plurality of second ribs is longer than a length in the width direction of each of the supporting surfaces of the plurality of first ribs, and is shorter than a length in the width direction of a contacting surface on the sheet in each of the plurality of rollers.

Due to the present configuration, the waveform shape along the width direction of the sheet formed by the first rib changes gradually as the sheet is conveyed downstream in the conveyance direction to reach the second rib and then reach the roller. As a result, loss of waveform shape when the sheet enters the roller can be reduced. In other words, the waveform shape of the sheet can be favorably maintained on the platen.

DESCRIPTION OF THE EMBODIMENTS

An embodiment of the present teaching will be described below. Note that the embodiment described below is merely an example of the present teaching, and it goes without saying that the embodiment of the present teaching may be appropriately changed in a range that does not alter the gist of the present teaching. Moreover, in the description below, an up-down direction7is defined with reference to a state in which a multifunction peripheral10is usably disposed (state ofFIG. 1), a front-rear direction8is defined assuming a surface provided with an opening13to be a front surface14, and a left-right direction9is defined viewing the multifunction peripheral10from the front. The up-down direction7, the front-rear direction8, and the left-right direction9are orthogonal to each other.

[Overall Structure of Multifunction Peripheral10]

As depicted inFIG. 1, the multifunction peripheral10(an example of an ink-jet recording apparatus) is roughly formed into a thin type rectangular parallelepiped. A printer unit11is provided in a lower part of the multifunction peripheral10. The multifunction peripheral10has various functions such as a facsimile function and a print function. As the print function, the multifunction peripheral10has a function of recording an image on one surface of a sheet12(refer toFIG. 2, an example of a sheet) by an ink-jet system. Note that the multifunction peripheral10may record an image on one surface and both surfaces of the sheet12.

As depicted inFIG. 1, the opening13is formed in a front surface of the printer unit11. The feed tray20is movable in the front-rear direction8. In other words, the feed tray20is insertable into and removable from the printer unit11via the opening13. The feed tray20is a box-shaped member which is open at its upper side. As depicted inFIG. 2, sheets12are supported in a stacked state on a bottom plate22of the feed tray20. A discharge tray21is supported above a front part of the feed tray20. The discharge tray21moves in the front-rear direction8integrally with the feed tray20. The sheet12on which an image is recorded by a recording unit24, is discharged onto an upper surface of the discharge tray21. Note that the discharge tray21may be supported by the printer unit11.

As depicted inFIG. 2, a feed unit16is disposed below the recording unit24. The feed unit16includes a feed roller25, a feed arm26, a drive transmitting mechanism27, and a shaft28. The feed roller25is rotatably supported by a distal end of the feed arm26. The feed arm26pivots in directions of an arrow29, with the shaft28disposed at a basal end of the feed arm26as a center. As a result, the feed roller25is capable of abutting on and separating from the feed tray20or the sheet12supported by the feed tray20.

The feed roller25rotates by a driving force of a feed motor (not illustrated) being transmitted to the feed roller25by the drive transmitting mechanism27which is configured by a plurality of gears being meshed with each other. As a result, an uppermost sheet12abutting on the feed roller25, of the sheets12supported by the bottom plate22of the feed tray20is fed to a conveyance path65. Note that the drive transmitting mechanism27is not limited to a gear mechanism in which a plurality of gears are meshed with each other. For example, the drive transmitting mechanism27may be a belt stretched between the shaft28and a shaft of the feed roller25.

As depicted inFIG. 2, the conveyance path65is extended out from a rear end of the feed tray20. The conveyance path65includes a curved part33and a linear part34. The curved part33extends upwardly making a U-turn from a rearward direction to a frontward direction. The linear part34roughly extends along the front-rear direction8.

The curved part33is formed by an outer guide member18and an inner guide member19facing each other separated by a certain spacing. Each of the guide members18,19extends in the left-right direction9(an example of a width direction) which is a direction orthogonal to a plane of paper inFIG. 2. The linear part34is formed by a conveyance roller pair59, the recording unit24and a platen42that face each other separated by a certain spacing, and a discharge roller pair44.

The sheet12supported by the feed tray20is conveyed along the curved part33by the feed roller25to reach the conveyance roller pair59. The sheet12sandwiched by the conveyance roller pair59is conveyed frontwards toward the recording unit24, along the linear part34. The sheet12that has reached directly below the recording unit24has an image recorded thereon by the recording unit24. The sheet12on which the image has been recorded is conveyed frontwards along the linear part34to be discharged on the discharge tray21. As described above, the sheet12is conveyed along a conveyance direction15indicated by arrows of a dot-chain line inFIG. 2.

As depicted inFIG. 2, the recording unit24is disposed above the linear part34. The platen42supporting the sheet12conveyed in the conveyance direction15along the linear part34of the conveyance path65is disposed in a position below the linear part34and facing the recording unit24.

The recording unit24includes a carriage40and a recording head38. The carriage40is supported by two guide rails56,57which are disposed with a spacing therebetween in the front-rear direction8, and is movable over the guide rails56,57along the left-right direction9. The guide rail56is disposed more upstream in the conveyance direction15than the recording head38. The guide rail57is disposed more downstream in the conveyance direction15than the recording head38. The guide rails56,57are supported by a pair of side frames (not illustrated) disposed outwardly of the linear part34of the conveyance path65in the left-right direction9. The carriage40moves by being applied with a drive force from a carriage drive motor (not illustrated).

The recording head38is mounted in the carriage40. The recording head38is supplied with ink from an ink cartridge (not illustrated). A plurality of nozzles39are formed in a lower surface of the recording head38. When the carriage40is moving in the left-right direction9, the recording head38discharges an ink droplet from the nozzle39, toward the platen42. As a result, the sheet12conveyed in the conveying orientation15along the linear part34to be supported by the platen42, is recorded with an image.

As depicted inFIG. 2, the conveyance roller pair59is disposed more upstream in the conveyance direction15than the recording head38in the linear part34. The discharge roller pair44is disposed more downstream in the conveyance direction15than the recording head38in the linear part34.

The conveyance roller pair59includes: a conveyance roller60; and a pinch roller61which is disposed below the conveyance roller60so as to face the conveyance roller60. As depicted inFIG. 3, the conveyance roller60is a cylindrical member extending in the left-right direction9. The conveyance roller60is rotatably supported by a pair of side frames of the multifunction peripheral10(not illustrated). A plurality of the pinch rollers61are provided, respectively disposed with a spacing between them in the left-right direction9. Each of the pinch rollers61is pressed toward the conveyance roller60by an elastic member (not illustrated) such as a coil spring.

A surface60A (refer toFIG. 4) of the conveyance roller60abuts on a first surface (surface facing the recording unit24) of the sheet12and surfaces61A (refer toFIG. 4) of each of the pinch rollers61abut on a second surface (surface opposite the first surface) of the sheet12. As a result, the conveyance roller pair59can sandwich the sheet12.

As depicted inFIG. 2, the discharge roller pair44includes: a discharge roller62; and a spur roller63which is disposed above the discharge roller62so as to face the discharge roller62. As depicted inFIG. 3, the discharge roller62includes: a shaft64extending in the left-right direction9orthogonal to the conveyance direction15; and a plurality of roller parts58(an example of a plurality of rollers) each attached to the shaft64so as to surround it, respectively having a spacing between them in the left-right direction9. The discharge roller62is rotatably supported by a pair of side frames (not illustrated). A plurality of the spur rollers63depicted inFIG. 2are provided, respectively disposed with a spacing between them in the left-right direction9. Each of the spur rollers63is disposed facing each of the roller parts58in the left-right direction9. Each of the spur rollers63is pressed toward each of the roller parts58by an elastic member (not illustrated) such as a coil spring. Note that inFIGS. 3 and 4, illustration of the spur roller63is omitted.

Surfaces58A (an example of abutting surfaces, refer toFIG. 4) of each of the roller parts58of the discharge roller62abut on the second surface of the sheet12, and tips of teeth of gear wheels configuring each of the spur rollers63abut on the first surface of the sheet12. As a result, the discharge roller pair44can sandwich the sheet12.

The conveyance roller60and the discharge roller62rotate by a drive force from a conveyance motor (not illustrated). When the conveyance roller60rotates in a state that the sheet12is sandwiched by the conveyance roller pair59, said sheet12is conveyed in the conveyance direction15by the conveyance roller pair59and conveyed onto the platen42. When the discharge roller62rotates in a state that the sheet12is sandwiched by the discharge roller pair44, the sheet12is conveyed in the conveyance direction15by the discharge roller pair44and discharged onto the discharge tray21.

As depicted inFIG. 2, a contacting member81is disposed more upstream in the conveyance direction15than the nozzle39formed in the recording head38. The contacting member81is molded by a synthetic resin (for example, polyacetal (POM)). Note that the contacting member81may be configured by a plurality of members being combined. For example, a plurality of members can be combined by the engagement.

As depicted inFIG. 3, a plurality of the contacting members81are provided, respectively disposed with a spacing between them in the left-right direction9. In the present embodiment, the number of contacting members81is nine, but the number of the contacting member81may be other than nine.

Each of the contacting members81has its upstream end81B in the conveyance direction15attached to the guide rail56by a publicly known means such as engagement.

Each of the contacting members81curves downwards and frontwards from the upstream end81B. As a result, each of the contacting members81is provided extending to an upstream vicinity in the conveyance direction15of the nozzle39disposed most upstream, of the plurality of nozzles39. Moreover, each of the contacting members81is provided extending toward the platen42in the up-down direction7. A downstream end81A (an example of a contacting section, refer toFIG. 2) in the conveyance direction15of each of the contacting members81can abut or contact on an upper surface of the sheet12supported by the platen42.

As depicted inFIG. 2, the platen42is disposed between the conveyance roller pair59and the discharge roller pair44in the linear part34of the conveyance path65.

As depicted inFIG. 4, the platen42includes a main body77, a housing79, a first rib91, a second rib92, and a third rib93. The main body77is configured in a plate shape. The housing79is a portion for housing an ink absorbing material82that absorbs ink, and is extended out downstream in the conveyance direction15from the main body77. The first rib91, the second rib92, and the third rib93support the sheet12. The first rib91and the third rib93are projected upwardly from the main body77and are extended out along the conveyance direction15. The second rib92is projected upwardly and downstream in the conveying orientation15from a downstream edge of the main body77.

As depicted inFIGS. 3 and 4, the main body77is a plate-shaped member whose lengths in the left-right direction9and the front-rear direction8are longer than its length in the up-down direction7. The length in the left-right direction9of the main body77is longer than its length in the front-rear direction8. The main body77is disposed facing the nozzle39formed in the recording head38.

As depicted inFIG. 3, an upper surface80of the main body77is a surface extending in the front-rear direction8and the left-right direction9. The upper surface80includes a first area80A, a second area80B, and a third area80C. The first area80A is an area positioned directly below a periphery of an end in the conveyance direction15of the sheet12when a so-called borderless printing where the recording unit24discharges an ink droplet to an edge of the sheet12is executed. The second area80B is an area positioned directly below a periphery of a right end and a left end of the sheet12of various kinds of sizes that are printable in the multifunction peripheral10, when the borderless printing is executed. The third area80C is an area positioned other than directly below the end in the conveyance direction15and the right end and left end of the sheet12, when the borderless printing is executed. When the borderless printing is executed, the ink droplet is impacted on and adheres to part of the first area80A and the second area80B (a portion where the sheet12is not supported).

The first area80A is an area more downstream in the conveyance direction15than the third area80C. An upstream end in the conveyance direction15of the first area80A is positioned between the nozzle39positioned most upstream and the nozzle39positioned most downstream in the conveyance direction15, of the plurality of nozzles39of the recording head38. A downstream end in the conveyance direction15of the first area80A is in substantially the same position as the nozzle39positioned most downstream in the conveyance direction15, of the plurality of nozzles39of the recording head38.

An upstream end in the conveyance direction15of the second area80B is positioned more upstream in the conveyance direction15than the nozzle39of the recording head38. A downstream end in the conveyance direction15of the second area80B is in substantially the same position as a position71of the nozzle39positioned most downstream in the conveyance direction15, of the plurality of nozzles39of the recording head38.

An upstream end in the conveyance direction15of the third area80C is positioned more upstream in the conveyance direction15than the nozzle39of the recording head38. A downstream end in the conveyance direction15of the third area80C is positioned between the nozzle39positioned most upstream in the conveyance direction15and the nozzle39in the most downstream position71, of the plurality of nozzles39of the recording head38.

The first rib91, the second rib92, and the third rib93support the sheet12by their upper surfaces91A,92A, and93A (refer toFIG. 4) contacting from below on the second surface of the sheet12. As a result, there is a reduction in ink that has adhered to the first area80A and the second area80B adhering to a lower surface of the sheet12. The first rib91, the second rib92, and the third rib93will be described later.

As depicted inFIG. 4, the housing79is extended out from a downstream edge in the conveyance direction15of the main body77. The housing79includes a recess partitioned by a side surface79A, a bottom surface79B, and a side surface79C. The side surface79A extends downwardly from a downstream edge in the conveyance direction15of the main body77. The bottom surface79B extends in the conveyance direction15from a lower edge of the side surface79A. The side surface79C extends upwardly from a downstream edge in the conveyance direction15of the bottom surface79B. The side surfaces79A,79C are surfaces extending in the up-down direction7and the left-right direction9. The bottom surface79B is a surface extending in the front-rear direction8and the left-right direction9. The ink absorbing material82is housed in the housing79. The ink absorbing material82is a porous material such as foamed polyurethane.

The upper surface80of the main body77inclines slightly downwardly in the conveyance direction15. As a result, ink that has adhered to the upper surface80(first area80A and second area80B) flows in the conveyance direction15. Ink that has reached a downstream edge in the conveyance direction15of the upper surface80flows along the side surface79A, is led to the ink absorbing material82, and is absorbed by the ink absorbing material82.

As depicted inFIGS. 3 and 4, a downstream supporting portion78is provided more downstream in the conveyance direction15than the platen42, with a spacing between itself and the platen42. The downstream supporting portion78is a plate-shaped member whose lengths in the front-rear direction8and the left-right direction9are longer than its length in the up-down direction7. The length in the left-right direction9of the downstream supporting portion78is longer than its length in the front-rear direction8. The downstream supporting portion78is supported by a pair of side frames at its right end and its left end. The downstream supporting portion78is a member that supports the sheet12conveyed from the platen42to guide the sheet12toward the discharge roller pair44.

As depicted inFIG. 4, an upstream end78A in the conveyance direction15of the downstream supporting portion78is positioned above the housing79of the platen42. In addition, an upstream edge in the conveyance direction15of the downstream supporting portion78faces a downstream edge in the conveyance direction15of the main body77of the platen42, with a spacing in the conveyance direction15between the edges. Ink that has adhered to the first area80A and the second area80B of the upper surface80of the platen42is led to the housing79from a gap between the platen42and the downstream supporting portion78.

As depicted inFIG. 3, a recess70receding in the conveyance direction15is formed in the upstream edge in the conveyance direction15of the downstream supporting portion78. The gap in the conveyance direction15between the platen42and the downstream supporting portion78is large at a place where the recess70is formed. As will be described later, the second rib92is positioned within the recess70.

As depicted inFIG. 3, the first rib91is formed on the upper surface80of the main body77. The first rib91extends along the conveyance direction15, from an upstream edge to a downstream edge in the conveyance direction15of the third area80C.

A plurality of the first ribs91are provided, respectively disposed with a spacing between them in the left-right direction9. Each of the first ribs91is positioned between a right edge and a left edge of each of the roller parts58of the discharge roller62. Note that part of each of the first ribs91may be positioned more rightward than the right edge of each of the roller parts58or more leftward than the left edge of each of the roller parts58. In other words, each of the first ribs91need only be provided at a position where at least part of it overlaps each of the roller parts58in the left-right direction9. In other words, each of the first ribs91need only be provided such that at least part of it overlaps each of the roller parts58, when viewed from the front-rear direction8.

Moreover, each of the first ribs91is formed between the downstream ends81A of the plurality of contacting members81adjacent in the left-right direction9.

Each of the first ribs91supports the sheet12at its upper surface91A. As depicted inFIG. 4, the upper surface91A of each of the first ribs91is positioned more downwardly than an upper edge of the surface58A of each of the roller parts58of the discharge roller62.

Moreover, the upper surface91A of each of the first ribs91is positioned more upwardly than a place where the downstream end81A of the contacting member81abuts or contacts on the upper surface of the sheet12. As depicted inFIG. 5, due to each of the first ribs91being configured as above, the sheet12supported by the upper surfaces91A of each of the first ribs91and abutted on by the downstream ends81A of each of the contacting members81is made into a waveform shape continuous in the left-right direction9. In other words, each of the first ribs91cooperates with the downstream end81A of each of the contacting members81by supporting the sheet12, thereby giving the sheet12a waveform shape along the left-right direction9.

As depicted inFIG. 3, the second rib92is extended out downstream in the conveyance direction15from the downstream edge of the main body77. In other words, the second rib92is disposed more downstream in the conveyance direction15than the first rib91, with a spacing in the conveyance direction15between itself and the first rib91. Describing this yet another way, the second rib92is disposed more downstream in the conveyance direction15than the nozzle39.

Moreover, the second rib92is disposed more upstream in the conveyance direction15than the roller part58of the discharge roller62. From the above, the second rib92is provided between the plurality of first ribs91and the plurality of roller parts58in the conveyance direction15.

A plurality of the second ribs92are provided, respectively disposed with a spacing between them in the left-right direction9. Each of the second ribs92is positioned within the recess70of the downstream supporting portion78.

Each of the second ribs92is positioned between the right edge and the left edge of each of the roller parts58of the discharge roller62. Note that part of each of the second ribs92may be positioned more rightward than the right edge of each of the roller parts58or more leftward than the left edge of each of the roller parts58. In other words, each of the second ribs92need only be provided at a position where at least part of it overlaps each of the roller parts58in the left-right direction9. In other words, each of the second ribs92need only be provided such that at least part of it overlaps each of the roller parts58, when viewed from the front-rear direction8.

Each of the first ribs91is positioned between a right edge and a left edge of each of the second ribs92. Note that part of each of the first ribs91may be positioned more rightward than the right edge of each of the second ribs92or more leftward than the left edge of each of the second ribs92. In other words, each of the second ribs92need only be provided at a position where at least part of it overlaps each of the first ribs91in the left-right direction9. In other words, each of the second ribs92need only be provided such that at least part of it overlaps each of the first ribs91, when viewed from the front-rear direction8.

Each of the second ribs92supports the sheet12at its upper surface92A. As depicted inFIG. 4, the upper surface92A of each of the second ribs92has substantially the same height as the upper surface91A of each of the first ribs91, but may be positioned more downwardly than the upper surface91A of each of the first ribs91. Moreover, the upper surface92A of each of the second ribs92is positioned more downwardly than the upper edge of the surface58A of each of the roller parts58of the discharge roller62.

As depicted inFIG. 3, the third rib93is formed on the upper surface80of the main body77. The third rib93is provided in the first area80A and the second area80B. The third rib93extends along the conveyance direction15, from an upstream edge to a downstream edge of the first area80A, in the conveyance direction15. In other words, the third rib93is provided between the first rib91and the second rib92in the conveyance direction15.

A plurality of the third ribs93are formed with a spacing between them in the left-right direction9. Each of the third ribs93is provided between adjacent first ribs91and between adjacent second ribs92, in the left-right direction9. Moreover, each of the third ribs93is positioned between a right edge and a left edge of the downstream end81A of each of the contacting members81. Note that part of each of the third ribs93may be positioned more rightward than the right edge of each of the downstream ends81A or more leftward than the left edge of each of the downstream ends81A.

Each of the third ribs93supports the sheet12at its upper surface93A. As depicted inFIG. 4, the upper surface93A of each of the third ribs93is positioned more downwardly than the upper surface91A of each of the first ribs91and the upper surface92A of each of the second ribs92.

As depicted inFIG. 3, a length L2in the left-right direction9of a supporting surface92B of the sheet12in each of the second ribs92is longer than a length L1in the left-right direction9of a supporting surface91B of the sheet12in each of the first ribs91. Moreover, a length L3in the left-right direction9of the surface58A of each of the roller parts58of the discharge roller62is longer than the length L2in the left-right direction9of the supporting surface92B of each of the second ribs92.

The supporting surface91B is defined as a portion abutted on by the sheet12, of the upper surface91A of each of the first ribs91. The length L1in the left-right direction9of the supporting surface91B is a distance (length in the left-right direction9) between a right edge and a left edge in a portion where the sheet12and the supporting surface91B abut on each other.

The supporting surface92B is a portion abutted on by the sheet12, of the upper surface92A of each of the second ribs92. The length L2in the left-right direction9of the supporting surface92B is a distance (length in the left-right direction9) between a right edge and a left edge in a portion where the sheet12and the supporting surface92B abut on each other.

For example, as depicted inFIG. 6A, when the upper surface91A of the first rib91is a plane surface and the sheet12abuts on only the right end and the left end of the upper surface91A and does not abut on a middle part of the upper surface91A, the length in the left-right direction9of the supporting surface91B is a length indicated by L1inFIG. 6A. In other words, in this case, the length in the left-right direction9of the upper surface91A and the length L1in the left-right direction9of the supporting surface91B are identical. The same applies also to the upper surface92A of the second rib92.

Moreover, for example, as depicted inFIG. 6B, when the upper surface91A of the first rib91is a curved surface and the sheet12abuts on only the middle part of the upper surface91A and does not abut on the right end and the left end of the upper surface91A, the length in the left-right direction9of the supporting surface91B is the length between the right edge and the left edge of the portion where the supporting surface91A and the sheet12abut on each other. In other words, it is a length indicated by L1inFIG. 6B. In other words, in this case, the length in the left-right direction9of the upper surface91A is longer than the length L1in the left-right direction9of the supporting surface91B. The same applies also to the upper surface92A of the second rib92.

Moreover, for example, as depicted inFIG. 6C, when the length in the left-right direction9of the upper surface91A of the first rib91and the length in the left-right direction9of the upper surface92A of the second rib92are equal, both being a length indicated by L4, and a radius of curvature of the upper surface92A of the second rib92is larger than a radius of curvature of the upper surface91A of the first rib91, the length in the left-right direction9of the supporting surface91B is a length indicated by L1, and the length in the left-right direction9of the supporting surface92B is a length indicated by L2. In this case, the length L2in the left-right direction9of the supporting surface92B of the second rib92is longer than the length L1in the left-right direction9of the supporting surface91B of the first rib91.

Note that the lengths in the left-right direction9of the supporting surfaces91B,92B may be different lengths according to the likes of a curved state of the sheet12, a spacing in the left-right direction9of each of the ribs91, a spacing in the left-right direction9of each of the ribs92, a spacing in the left-right direction9between each of the ribs91,92and the downstream end81A of each of the contacting members81, a length in the up-down direction7between an upper edge of each of the ribs91,92and a lower edge of the downstream end81A of each of the contacting members81, shapes of the upper surfaces91A,92A of each of the ribs91,92, and so on.

The surface58A is a surface abutted on by the sheet12in each of the roller parts58. The length L3in the left-right direction9of the surface58A is a length from a right edge to a left edge of a surface facing outwardly in a radial direction of each of the roller parts58.

Effects of Embodiment

Due to the present embodiment, the length L2in the left-right direction9of the upper surface92A of each of the second ribs92is longer than the length L1in the left-right direction9of the upper surface91A of each of the first ribs91and shorter than the length L3in the left-right direction9of the surface58A of each of the roller parts58of the discharge roller62. Therefore, the waveform shape along the left-right direction9of the sheet12formed by the first rib91gradually changes as the sheet12is conveyed downstream in the conveyance direction15to reach the second rib92and then reach the roller part58. As a result, loss of the waveform shape during entry to the roller part58of the sheet12can be reduced.

Moreover, due to the present embodiment, each of the second ribs92is disposed more downstream in the conveyance direction15than the nozzle39. As a result, the waveform shape along the left-right direction9in a portion facing the nozzle39of the sheet12can be formed by only the first rib91. As a result, the waveform shape along the left-right direction9in the portion facing the nozzle39of the sheet12can be maintained in a constant shape.

Moreover, due to the present embodiment, each of the second ribs92is disposed with a spacing between it and each of the first ribs91in the conveyance direction15. As a result, an area (first area81A) of the platen42between the first rib91and the second rib92in the conveyance direction15can be utilized as an area impacted on by the ink droplet discharged to an outer edge part of the sheet12during the so-called borderless printing. In other words, the multifunction peripheral10according to the present embodiment can be configured as an apparatus capable of borderless printing.

Moreover, due to the present embodiment, a portion of a trough of the waveform shape in the sheet12is supported by the third rib93, between the first rib91and the second rib92in the conveyance direction15. As a result, adherence to the sheet12of ink that has impacted on the first area81A between the first rib91and the second rib92in the conveyance direction15, can be reduced during borderless printing.

Moreover, due to the present embodiment, each of the first ribs91and the downstream end81of each of the contacting members81cooperate to enable the sheet12to be given the waveform shape along the left-right direction9. As a result, a stable waveform shape can be given to the sheet12.

Modified Embodiments

The length in the left-right direction9of the upper surface92A of each of the second ribs92is preferably within an area94indicated by hatching inFIG. 7A. Now, the area94is an area surrounded by: a straight line R1joining downstream edges in the conveyance direction15of each of the contacting members81; a straight line R2joining a rear right edge BR of each of the roller parts58of the discharge roller62and one of intersection point C1of the straight line R1and each of the first ribs91; a straight line R3joining a rear left edge BL of each of the roller parts58of the discharge roller62and one of intersection point C2of the straight line R1and each of the first ribs91; and a rear edge of each of the roller parts58.

Moreover, as depicted inFIG. 7B, each of the second ribs92may be configured such that the length in the left-right direction9of its upper surface92A becomes longer as progress is made downstream in the conveyance direction15.

Due to the above-described modified embodiment, a gradual change accompanying progress downstream in the conveyance direction15, of the waveform shape along the left-right direction9of the sheet12formed by each of the first ribs91, can be made finer. As a result, loss of the waveform shape during entry to the roller part58of the sheet12can be reduced even more than in the above-described embodiment.

Moreover, as depicted inFIG. 8A, each of the first ribs91, similarly to each of the second ribs92, may also be configured such that the length in the left-right direction9of its upper surface91A becomes longer as progress is made downstream in the conveyance direction15.

Note that inFIGS. 7, 8A, and later-described9, the third rib93is not depicted, but in the case of configurations depicted inFIGS. 7, 8A, and 9, presence/absence of the third rib93is arbitrary.

Moreover, in the above-described embodiment, each of the second ribs92was disposed with a spacing in the conveyance direction15between itself and each of the first ribs91. However, as depicted inFIG. 8B, each of the second ribs92may be joined to each of the first ribs91in the conveyance direction15.

In addition, as depicted inFIG. 9, the first rib91and the second rib92may be configured by a plurality of ribs disposed with a spacing between them in the conveyance direction15. Note that when the platen42includes the third rib93, the third rib93may also be configured by a plurality of ribs disposed with a spacing between them in the conveyance direction15.

Moreover, in the above-described embodiment, the second rib92was provided in the platen42. However, the second rib92may be provided in other than the platen42, for example, in the downstream supporting portion78.

Moreover, in the above-described embodiment, the discharge roller62was disposed more downwardly than the spur roller63in the discharge roller pair44, but the discharge roller62may be disposed more upwardly than the spur roller63. In this case, the surface58A of each of the roller parts58of the discharge roller62abuts on the first surface of the sheet12, and the tips of the teeth of the gear wheels configuring each of the spur rollers63abut on the second surface of the sheet12, thereby enabling the discharge roller pair44to sandwich the sheet12.