Recording apparatus

There is provided a recording apparatus including a recording head, a support member which is disposed to face the recording head and on which a plurality of ribs for supporting a medium are formed, the plurality of ribs include a plurality of first ribs which are provided in a medium width direction and a plurality of second ribs which are positioned on a downstream side from the first ribs and are provided in the medium width direction, each of the second ribs has a guide surface for scooping up a leading edge of the medium which is fed backward, and the guide surface includes a first guide surface which is formed on each of the second ribs and a second guide surface which is formed on each of the second ribs.

BACKGROUND

1. Technical Field

The present invention relates to a recording apparatus for performing recording on a medium.

2. Related Art

In recording apparatuses represented by a facsimile machine, a printer, or the like, particularly an ink jet printer, a support member (also referred to as a platen) is provided at a position facing a recording head, the support member including a plurality of ribs for supporting a recording paper as a medium which are disposed at an appropriate interval along a direction orthogonal to a paper transport direction, that is, a paper width direction (see, for example, Japanese Patent No. 5962561).

The recording paper swells by absorbing ink and forms a corrugation shape (cockling) in which a mountain is formed at a position of the rib of the support member, and a valley is formed between the ribs.

In a case where recording is performed on both surfaces of the recording paper, the recording paper for which recording has been performed on a first surface is not discharged but is fed backward, and is transported again to the recording position via a reverse path. In a case where the backward feeding is performed, it is preferable to form a guide slope for scooping up a paper leading edge (a trailing edge when recording is performed on the first surface) on a transport direction-downstream side of the rib (a downstream side on the basis of a forward feeding direction of the recording paper) so that the paper leading edge is prevented from getting caught in the rib.

FIG. 12is a schematic diagram for describing a technical problem of the invention. Reference numeral105indicates a recording head, and at positions facing the recording head105, there are provided a first rib101, a second rib102, a third rib103, and a fourth rib104from an upstream side toward a downstream side in the forward feeding direction (from right to left in the drawing) of the recording paper.

The trailing edge of the recording paper P for which recording is to be performed on both surfaces is transported in a backward feeding direction (from left to right in the drawing) after recording has been performed on the first surface. Thus, the guide slope for scooping up the paper leading edge Pt is formed so that the paper leading edge Pt is prevented from getting caught in each rib at the time of being fed backward. As an example, reference numeral Sa indicates a guide slope formed on a downstream side of the second rib102in the forward feeding direction.

It is preferable that the guide slope Sa be made longer and a start position thereof be at a lower side, from the viewpoint of scooping up the paper leading edge Pt. However, in a case where the guide slope Sa is formed to be long, for example, as indicated by a broken line and reference numeral Sb, a length of the second rib102also has to be increased.

In a borderless recording in which recording without any margin is performed on edges of the recording paper P, a space between the ribs is used as an ink disposal area. Thus, in a case where a length of the rib itself is long, the ink disposal area narrows, thereby inevitably restricting the number of ink ejection nozzles to be used. Referring toFIG. 12, a range L1indicates a usable range for the ink ejection nozzles in a case of the guide slope Sa, and a range L2indicates a usable range for the ink ejection nozzles in a case of the guide slope Sb. As shown in the drawing, in the case of the guide slope Sb which is made longer and of which the start position is at a lower side, the usable range for the ink ejection nozzles narrows, and as a result, a printing throughput is lowered.

SUMMARY

An advantage of some aspects of the invention is to provide a recording apparatus which takes into consideration both a paper leading edge getting caught in a rib when a recording paper is fed backward and prevention of a printing throughput from being lowered.

According to an aspect of the invention, there is provided a recording apparatus including: a recording head which performs recording on a medium; a support member which is disposed to face the recording head and on which a plurality of ribs for supporting the medium are formed, the plurality of ribs include a plurality of first ribs which are spaced apart from one another at an appropriate interval in a medium width direction that is a direction intersecting with the medium transport direction, and a plurality of second ribs which are positioned on a downstream side from the first ribs in the medium transport direction, and are spaced apart from one another at an appropriate interval in the medium width direction, in which each of the second ribs has a guide surface for scooping up a leading edge of the medium which is fed backward from a downstream side to an upstream side in the medium transport direction, in which the guide surface includes a first guide surface which is formed on each of the second ribs positioned within a first region in the medium width direction, and a second guide surface which is formed on each of the second ribs positioned outside the first region in the medium width direction, and in which a medium transport direction-downstream side end portion of the second guide surface is positioned on a downstream side from a medium transport direction-downstream side end portion of the first guide surface and has a lower height position than a height position for the medium transport direction-downstream side end portion of the first guide surface.

A borderless recording, for example, tends to be performed more frequently for a medium having a relatively small size such as an L-type photograph size than a medium having a relatively large size such as an A4 size. Therefore, prioritizing a throughput of the borderless recording for a medium having a small size over a throughput of the borderless recording for a medium having a large size is in line with users' needs.

Further, regarding the medium having a small size such as an L-type photograph size, for which the borderless recording is performed at a high frequency as described above, a dedicated paper is often used. In this case, because of a high paper stiffness (rigidity), hanging-down at a leading edge hardly occurs, that is, getting-caught of a medium leading edge in a rib at the time of being fed backward hardly occurs. In addition, there are few cases where recording is performed by backward feeding.

On the contrary, regarding the medium having a relatively large size such as an A4 size, a plain paper is often used. In this case, because of a low paper stiffness (rigidity), hanging-down at the leading edge easily occurs, that is, getting-caught of the medium leading edge in the rib at the time of being fed backward easily occurs. In addition, even in a case of having a somewhat strong paper stiffness (rigidity), influence of curls also becomes large as a size of the medium increases, and getting-caught of the medium leading edge in the rib at the time of being fed backward easily occurs. Therefore, it is reasonable to prioritize prevention of the medium having a large size from getting caught in the rib over prevention of the medium having a small size from getting caught in the rib, from the viewpoint of obtaining a good recording result as a whole.

In this case, the above natures are utilized to make a configuration as follows. That is, in a configuration including the first ribs and the second ribs, each of the second ribs has a guide surface for scooping up the leading edge of the medium which is fed backward from the downstream side to the upstream side in the medium transport direction. The guide surface includes a first guide surface which is formed on each of the second ribs positioned within a first region in the medium width direction, and a second guide surface which is formed on each of the second ribs positioned outside the first region in the medium width direction, in which a medium transport direction-downstream side end portion of the second guide surface is positioned on a downstream side from a medium transport direction-downstream side end portion of the first guide surface and has a lower height position than a height position for the medium transport direction-downstream side end portion of the first guide surface.

That is, outside the first region, the guide surface (second guide surface) for scooping up the medium leading edge is formed to be longer and from a lower side. Thus, the leading edge of the medium having a large size can be prevented from getting caught in the rib.

On the other hand, in the first region, the guide surface (first guide surface) for scooping up the medium leading edge is shorter than the second guide surface. Thus, a region between the ribs (a region between the second rib and the third rib) can be secured wide, and a larger number of nozzles can be used, that is, restrictions on the ink ejection nozzles at the time of performing the borderless recording can be loosened, thereby preventing a recording throughput from being lowered.

In this way, it is possible to configure a recording apparatus which takes into consideration both the medium leading edge getting caught in the rib when the medium is fed backward and prevention of the recording throughput from being lowered.

In this specification, “medium transport direction” means a medium transport direction when recording is performed on the medium, that is, a forward feeding direction of the medium.

In the recording apparatus, the plurality of ribs may further include a plurality of third ribs which are positioned on a downstream side from the second ribs in the medium transport direction and are spaced apart from one another at an appropriate interval in the medium width direction, in which the recording head has a plurality of ink ejection nozzles along the medium transport direction, and in which the recording apparatus is capable of executing a first recording mode, in which the ink ejection nozzles to be used are restricted to the ink ejection nozzles which are positioned within a range between the medium transport direction-downstream side end portion of the second guide surface and an upstream side end portion of each of the third ribs in the medium transport direction, in a case where recording is performed on a wide medium of which edge portions in the medium width direction are positioned outside the first region, and a second recording mode, in which the ink ejection nozzles are positioned within a range between the medium transport direction-downstream side end portion of the first guide surface and the upstream side end portion of each of the third ribs in the medium transport direction and are used in a larger number than the ink ejection nozzles used in the first recording mode, in a case where recording is performed on a narrow medium of which edge portions in the medium width direction are positioned within the first region.

In this configuration, by applying the second recording mode to a medium of which width direction-edge portions are positioned within the first region, that is, a medium having a relatively small size, it is possible to use a larger number of ink ejection nozzles, thereby preventing a recording throughput from being lowered.

In the recording apparatus, the plurality of ribs may further include a plurality of fourth ribs which are positioned on a downstream side from the third ribs in the medium transport direction and are spaced apart from one another at an appropriate interval in the medium width direction, in which the plurality of ink ejection nozzles are configured to include a first nozzle group including the ink ejection nozzles which face a region between the first ribs and the second ribs in the medium transport direction, a second nozzle group including the ink ejection nozzles which face a region between the second ribs and the third ribs in the medium transport direction, and a third nozzle group including the ink ejection nozzles which face a region between the third ribs and the fourth ribs in the medium transport direction, and in which in the first recording mode, use of the ink ejection nozzles constituting the second nozzle group is restricted, and the number of the ink ejection nozzles constituting the first nozzle group or the third nozzle group matches the number of the ink ejection nozzles used in the second nozzle group.

In this configuration, in the first recording mode, use of the ink ejection nozzles constituting the second nozzle group is restricted, and the number of the ink ejection nozzles constituting the first nozzle group or the third nozzle group matches the number of the ink ejection nozzles used in the second nozzle group. Thus, in a case where inks of different colors are ejected from the first nozzle group, the second nozzle group, and the third nozzle group, and this is repeatedly done on the medium, an appropriate recording result can be obtained.

In the recording apparatus, an upstream side transport unit which is provided on an upstream side of the support member in a medium transport direction, a control unit which controls the upstream side transport unit may be further included, in which in a recording job in which recording is performed on both a first surface of the medium and a second surface opposite to the first surface, the control unit starts backward feeding of the medium at a position where the trailing edge of the medium for which recording on the first surface has been completed does not proceed to a downstream side from the third ribs.

In this configuration, in the recording job in which recording is performed on both the first surface of the medium and the second surface opposite to the first surface, the control unit which controls the upstream side transport unit starts backward feeding of the medium at the position where the trailing edge of the medium for which recording on the first surface has been completed does not proceed to a downstream side from the third ribs. Thus, the medium leading edge does not need to climb over the third ribs when the medium is fed backward, that is, it is possible to reduce the number of ribs over which the medium leading edge passes when the medium is fed backward, thereby suppressing a probability of jamming.

In the recording apparatus, the plurality of fourth ribs provided along the medium width direction may be formed to have uneven heights.

In this configuration, the plurality of fourth ribs provided along the medium width direction are formed to have uneven heights. Thus, by adjusting heights of the fourth ribs in response to heights of corrugation shaped valleys formed on the medium, it is possible to prevent the medium leading edge from colliding with the ribs and to realize a more appropriate transport of the medium.

In the recording apparatus, a position of the medium transport direction-upstream side end portion of each of the second ribs positioned within the first region and a position of the medium transport direction-upstream side end portion of each of the second ribs positioned outside the first region may match with each other.

In this configuration, the position of the medium transport direction-upstream side end portion of each of the second ribs positioned within the first region and the position of the medium transport direction-upstream side end portion of each of the second ribs positioned outside the first region match with each other. Thus, it is possible to allow the intervals between the first ribs and the second ribs in the medium transport direction to match with one another in the medium transport direction. As a result, regardless of a medium size, a region between the first ribs and the second ribs can be maximally used.

In the recording apparatus, each of the ribs may have an upstream guide surface for scooping up the leading edge of the medium which is fed forward from an upstream side to a downstream side in the medium transport direction.

In this configuration, each rib has the upstream guide surface for scooping up the leading edge of the medium which is fed forward from the upstream side to the downstream side in the medium transport direction. Thus, when the medium is transported in the forward feeding direction, it is possible to prevent the medium leading edge from getting caught in the rib.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, embodiments of the invention will be described with reference to the drawings. In the respective examples, the same configuration is designated by the same reference numeral and will be described in only a first example, and the description for the configuration will be omitted in the subsequent examples.

FIG. 1is an external perspective view of a printer according to the invention.FIG. 2is a perspective view of an apparatus main body according to the invention.FIG. 3is a side sectional view showing a medium transport path of the printer according to the invention.FIG. 4is a side sectional view showing a recording head and a support member in the printer according to the invention.

FIG. 5is a plan view of the support member as viewed from above.FIG. 6Ais a sectional view taken along sectional line VIA-VIA inFIG. 5, andFIG. 6Bis a sectional view taken along sectional line VIB-VIB inFIG. 5.FIG. 7is a perspective view of the support member.FIG. 8is a sectional view taken along a sectional line VIII-VIII inFIG. 7.

FIG. 9is a side sectional view showing a relationship between ink ejection regions of the recording head and ribs of the support member.FIG. 10is a schematic diagram for describing a first recording mode in the recording head.FIG. 11is a side view showing a relationship between a trailing edge of a medium and third ribs at the time of performing a both-surface recording.FIG. 12is a schematic diagram for describing the technical problem of the invention.

Further, in an XYZ coordinate system shown in each drawing, an X direction indicates a width direction of the medium, that is, an apparatus width direction, a Y direction indicates a transport direction of the medium in a transport path in the recording apparatus, that is, an apparatus depth direction, and a Z direction indicates an apparatus height direction.

Examples

Outline of Printer

Referring toFIG. 1, an overall configuration of a printer10is described. The printer10, which is an example of the recording apparatus, is configured as an ink jet printer. The printer10is configured as a multifunction machine including an apparatus main body12and a scanner unit14. The scanner unit14includes a scanner main body14aand an auto document feeder (ADF)14b.

On a front side of the apparatus main body12, an operating section16and a discharge port18are provided, and below the discharge port18, a medium receiving tray20is provided. Below the medium receiving tray20, a medium storage cassette22, which can be inserted into the apparatus main body12from the front side thereof and removed therefrom, is provided.

Referring toFIG. 2, in the front side of the apparatus main body12, on a −X axis direction side of the medium storage cassette22, an ink storage section24is provided. In the ink storage section24, a plurality of ink tanks are disposed. In the respective ink tanks, as an example, black ink, magenta ink, yellow ink, and cyan ink are respectively stored.

On a −Y direction side (a back side of the apparatus) of the ink storage section24in the Y axis direction (apparatus depth direction) of the apparatus main body12, a carriage26movable in the X axis direction is provided. Under the carriage26, a recording head28(FIG. 3) to be described later is provided. An ink tube30extends from each of the ink tanks in the ink storage section24. The ink tube30extends in the +X axis direction, then changes its direction by making an upward curve, extends in the −X axis direction, and is guided into the carriage26. In the lower surface of the recording head28, a plurality of ink ejection nozzles are provided and are configured to be capable of ejecting ink supplied via the ink tube30from each of the ink tanks in the ink storage section24.

Regarding Medium Transport Path

Referring toFIGS. 3 and 4, the medium transport path of the printer10will be described. In the −Y direction side of the apparatus main body12, above the medium storage cassette22, a pick-up roller32is disposed. The pick-up roller32is configured to be rotatable about a rotating shaft34as a support point. The pick-up roller32contacts the medium stored in the medium storage cassette22, thereby transporting the uppermost medium of the media stored in the medium storage cassette22to a transport direction-downstream side along the medium transport path. Referring toFIG. 3, a dash-single dotted line designated by reference numeral P1indicates a path of the medium which is sent out from the medium storage cassette22to the transport direction-downstream side in the apparatus main body12.

On a downstream side of the pick-up roller32in the medium transport direction, a feed roller36is provided. Around the feed roller36, driven rollers38a,38b,38c, and38dare provided so that each of the driven rollers38a,38b,38c, and38dcan be driven to rotate with respect to the feed roller36. The medium sent by the pick-up roller32is sent, via the feed roller36and the driven rollers38a,38b, and38c, to a transport roller40as “upstream side transport unit” disposed on the transport direction-upstream side.

On a downstream side of the transport roller40in the medium transport direction, the carriage26and the recording head28are provided. Below the recording head28, a support member42(FIG. 4) which faces the recording head28and supports the medium is provided. By supporting the medium from below, the support member42defines the distance (gap) between a recording surface of the medium and a head surface of the recording head28.

As shown inFIG. 4, in the Y-axis direction, a dash-double dotted line designated by a reference numeral Y1indicates a nozzle position which is the transport direction-most upstream in the recording head28, and a dash-double dotted line designated by a reference numeral Y2indicates a nozzle position which is the transport direction-most downstream in the recording head28. When the medium supported by the support member42faces a region from Y1to Y2of the recording head28in the medium transport direction, ink is ejected toward the medium from a plurality of nozzle holes in the recording head28and the ink lands on a recording surface (a surface facing the recording head28) of the medium, thereby executing recording. A configuration of a nozzle surface in the recording head28will be described later.

The medium on which recording has been executed by the recording head28is discharged to the medium receiving tray20through the discharge port18by a discharge roller44as “downstream side transport unit” disposed on the medium transport direction-downstream side with respect to the recording head28.

Referring back toFIG. 3, in the apparatus main body12, a control section46as “control unit” is provided. In this example, the control section46is, as an example, configured as an electric circuit having a plurality of electronic components. The control section46is, as an example, configured not only to control rotational drive of the pick-up roller32, the feed roller36, the transport roller40, and the discharge roller44, but also to control movement of the carriage26in the X axis direction, ink ejection operation of the recording head28, and the like.

Regarding Configuration of Support Member

Referring toFIGS. 4 to 8, a configuration of the support member42will be described. Referring toFIGS. 4 and 5, the support member42is disposed between the transport roller40and the discharge roller44in the transport direction. As shown inFIG. 5, the support member42extends in the X axis direction. On the upper surface of the support member42, a plurality of rib rows are provided while being spaced apart from one another at an appropriate interval from the transport direction-upstream side toward the transport direction-downstream side and protruding from the upper surface toward the recording head28side (upward). Specifically, on the transport direction-most upstream of the upper surface of the support member42, the first ribs48and50are formed while being spaced apart from one another at an appropriate interval in the X axis direction (medium width direction) that is a direction intersecting with the transport direction (Y axis direction).

On the transport direction-downstream side of the first ribs48and50, a plurality of second ribs52and54are provided while being spaced apart from one another at an appropriate interval in the X axis direction. On the transport direction-downstream side of the second ribs52and54, a plurality of third ribs56are provided while being spaced apart from one another at an appropriate interval in the X axis direction. On the transport direction-downstream side of the third ribs56, a plurality of fourth ribs58,60and62are provided while being spaced apart from one another at an appropriate interval in the X axis direction.

Furthermore, on the upper surface of the support member42, as an example, an ink absorbing member64formed of a sponge or the like is disposed. In this example, the ink absorbing member64is provided with an opening in response to a formation position of each rib. In a case where the ink absorbing member64is disposed on the support member42, each rib is configured to protrude upward from the opening.

In this example, the first rib48and the first rib50are configured so that the amount of protrusion from the support member42is different from each other. Specifically, as shown inFIG. 4, a configuration in which an upper surface48aof the first rib48is positioned above an upper surface50aof the first rib50can be employed. In this example, the first rib48and the first rib50are, as an example, disposed substantially alternately in the medium width direction (FIG. 5). In this example, the transport roller40transports the medium so that the medium is pressed against the first ribs48and50provided on the support member42. Accordingly, a mountain and a valley are formed on the medium in the medium width direction by the first rib48having a tall height and the first rib50having a low height. Thus, when the medium passes over the first ribs48and50, a corrugation shape (cockling) is easily formed on the medium.

Referring toFIGS. 4 and 9, on the transport direction-upstream side end portions of the first ribs48and50, upstream guide surfaces48band50bare respectively formed. In this example, the upstream guide surfaces48band50b(FIG. 4) are configured as uphill slopes extending from the transport direction-upstream side toward the transport direction-downstream side, and are connected to the upper surfaces48aand50a, respectively.

Referring toFIG. 5, a region designated by a reference numeral W1indicates a first region W1in the medium width direction, and a region designated by a reference numeral W2indicates a second region W2which is disposed outside the first region W1in the medium width direction. Here, a dash-double dotted line designated by a reference numeral P2indicates a medium of which a width is smaller than a width of the first region W1and of which a transport region in the medium width direction is positioned within the first region W1. In this example, the medium designated by the reference numeral P2indicates, as an example, a paper size of 4×6. In addition to this, as a paper size for a medium that uses the first region W1as a medium transport region, an A6 size, a postcard size, and the like can be mentioned.

On the other hand, a dash-double dotted line designated by a reference numeral P3indicates a medium of which a width is larger than the width of the first region W1and of which a transport region in the medium width direction is positioned within a second region W2beyond the first region W1. In this example, the medium designated by the reference numeral P3indicates, as an example, a paper size of A4. In addition to this, as a paper size for a medium that uses the first region W1and the second region W2as the medium transport region, a letter size and the like can be mentioned.

Referring toFIG. 5, in the first region W1, the second ribs52are disposed, and in the second region W2, the second ribs54are disposed. Referring toFIGS. 6A and 6B, configurations of the second ribs52and54, and the third rib56will be described.

As shown inFIGS. 6A and 6B, a position of a transport direction-upstream side end portion52aof the second rib52provided in the first region W1and a position of a transport direction-upstream side end portion54aof the second rib54provided in the second region W2are positioned at a position that is Y3in the medium transport direction, and the respective positions in the transport direction match with each other. “Positions match with each other” means that the positions are not only completely identical but also have errors occurring upon forming the second ribs52and54in the support member42, and the like.

In this example, a length of the second rib52in the transport direction is set to L3. On the other hand, a length of the second rib54in the transport direction is set to L4. In this example, the length L4is set to be longer than the length L3. Furthermore, a height position for an upper surface52bof the second rib52and an upper surface54bof the second rib54with respect to the support member42is set to a height h1.

As shown in the sectional view (VIB-VIB), in the second rib52, with respect to the medium transport direction, an upstream guide surface52cis formed on the transport direction-upstream side, and a first guide surface52dis formed on the transport direction-downstream side. In this example, the upstream guide surface52cis configured as an uphill slope while extending from the upstream side end portion52atoward the transport direction-downstream side. A length of the guide surface52cin the transport direction is set to L5. In this example, the upstream guide surface52cis configured as a guide surface for scooping up the leading edge of the medium which is transported from the upstream side toward the downstream side in the medium transport direction.

The first guide surface52dis configured as a downhill slope while extending from the upper surface52btoward the transport direction-downstream side. A length of the first guide surface52din the transport direction is set to L6. In this example, the length L5of the upstream guide surface52cin the transport direction is set to be longer than the length L6of the first guide surface52din the transport direction. Furthermore, in this example, a height position for a downstream side end portion52eof the first guide surface52dis set to a height h2with respect to the support member42.

Next, as shown in the sectional view (VIA-VIA), in the second rib54, with respect to the medium transport direction, an upstream guide surface54cis formed on the transport direction-upstream side, and a second guide surface54dis formed on the transport direction-downstream side. In this example, the upstream guide surface54cis configured as an uphill slope while extending from the upstream side end portion54atoward the transport direction-downstream side. A length of the upstream guide surface54cin the transport direction is set to L7. In this example, the upstream guide surface54cis also configured as a guide surface for scooping up the leading edge of the medium which is transported from the upstream side toward the downstream side in the medium transport direction. In this example, the length L7is set to be longer than the length L5or the length L6.

The second guide surface54dis configured as a downhill slope while extending from the upper surface54btoward the transport direction-downstream side. A length of the second guide surface54din the transport direction is set to L7. Furthermore, in this example, a height position for a downstream side end portion54eof the second guide surface54dis set to a height h3that is lower than the height h2.

In this example, a position of the transport direction-downstream side end portion54eof the second guide surface54dof the second rib54in the transport direction is positioned at a position Y4of the transport direction-downstream side which is positioned downstream from the position Y3by the length L4. That is, the transport direction-downstream side end portion54eof the second guide surface54din the medium transport direction is positioned on a downstream side from the transport direction-downstream side end portion52eof the first guide surface52d. Furthermore, the height position h3for the transport direction-downstream side end portion54eof the second guide surface54dwith respect to the support member42is set to be lower than the height position h2for the transport direction-downstream side end portion52eof the first guide surface52d.

As shown in the sectional views (VIA-VIA) and (VIB-VIB), the third rib56is disposed so that an upstream side end portion56athereof is positioned at a position Y5which is on a downstream side of each of the second ribs52and54in the medium transport direction. In this example, a length of the third rib56in the transport direction is set to L8. An upper surface56bof the third rib56is also set to a height h1similarly to the height position for the upper surface52bof the second rib52and the upper surface54bof the second rib54.

In the third rib56, on the transport direction-upstream side in the medium transport direction, an upstream guide surface56cis formed. In this example, the upstream guide surface56cis configured as an uphill slope while extending from the upstream side end portion56atoward the transport direction-downstream side. A length of the upstream guide surface56cin the transport direction is set to L9. In this example, as an example, the length L9is set to the same length as the length L3of the second rib52. However, the length L9may be changed as appropriate.

Here, referring back toFIG. 5, the medium P2which is transported using only the first region W1is a medium having a relatively small size such as an L-type photograph size, for which a dedicated paper having a high paper stiffness (rigidity) is often used. On the other hand, the medium P3which is transported using the first region W1and the second region W2is, for example, a medium having a relatively large size such as an A4 size, for which a plain paper having a low paper stiffness (rigidity) is used. As an example, in a case of the plain paper having a low paper stiffness (rigidity), the amount of hanging-down at the medium leading edge is greater than the amount of hanging-down at the leading edge of the dedicated paper having a high paper stiffness (rigidity).

In this example, the upstream guide surface54cand the second guide surface54dof the second rib54disposed in the second region W2outside the first region W1are set so that each guide surface has a long length in the transport direction and also has a large guiding amount (amount of variation in a height direction of the guide surface), compared to the upstream guide surface52cand the first guide surface52dof the second rib52disposed in the first region W1. Accordingly, in the medium P3having a low paper stiffness (rigidity), the leading edge (edge portion that becomes a head side in the transport direction) of the medium can be prevented from getting caught in the rib at the time of being fed forward (transported from the upstream side to the downstream side in the transport direction) and of being fed backward (transported from the downstream side to the upstream side in the transport direction).

Furthermore, in this example, the first guide surface52dis provided even in the second rib52corresponding to the medium P2that is a dedicated paper having as a high paper stiffness (rigidity). Thus, the leading edge of the medium P2can be prevented from getting caught in the second rib52at the time of being fed backward (transported from the downstream side to the upstream side in the transport direction).

Referring toFIGS. 7 and 8, fourth ribs58,60, and62will be described. The fourth ribs58,60, and62are disposed on a downstream side of the third rib56in the transport direction. As an example, the fourth ribs58,60, and62are configured so that each of the upper surfaces58a,60a, and62ahas a different height position with respect to the support member42. Referring toFIG. 8, the height position for the upper surface58aof the fourth rib58is set to a height h4with respect to the support member42, the height position for the upper surface60aof the fourth rib60is set to a height h5with respect to the support member42, and the height position for the upper surface62aof the fourth rib62is set to a height h6with respect to the support member42. Here, the respective heights in this example are set to have a relationship of h4>h5>h6.

In this example, the height h6for the fourth rib62is set to be the lowest. In a case where the height of the fourth rib62at a position where the fourth rib62is provided in the medium width direction is set to be lower than the heights h4and h5of other ribs58and60, for example, when a thin medium having a large width in the medium width direction is transported from the upstream side toward the downstream side in the transport direction, it is possible to prevent the leading edge of the medium from colliding with the fourth rib62. As a result, it is possible to stabilize a medium transport and to reduce printing defects in the recording head28.

In this example, as an example, as shown inFIG. 5, the fourth ribs58,60, and62are provided, respectively, in the medium width direction at positions corresponding to the positions where the first ribs48and50are provided. In particular, the fourth rib58having the highest height in the height direction is provided at a position corresponding to the first rib48having a tall height in the medium width direction.

Furthermore, on the transport direction-upstream side end portions of the respective ribs58,60, and62, upstream guide surfaces58b,60b, and62b(FIG. 4) are formed, respectively. In this example, the upstream guide surfaces58b,60b, and62bare configured as uphill slopes extending from the transport direction-upstream side toward the transport direction-downstream side, and are connected to the upper surfaces58a,60a, and62a(FIG. 9), respectively.

Regarding Configuration of Recording Head

Referring toFIG. 9, in the lower surface of the recording head28, a plurality of ink nozzles capable of ejecting ink are formed. More specifically, in a region from the position Y1to the position Y2in the medium transport direction, three nozzle groups66,68, and70are formed. In this example, a region designated by the reference numeral66in the medium transport direction is a first nozzle group66. The first nozzle group66faces a region between the first ribs48and50and the second ribs52and54in the medium transport direction, and includes a plurality of ink ejection nozzles capable of ejecting ink toward the region between the first ribs48and50and the second ribs52and54. As an example, the ink ejection nozzles of the first nozzle group66are configured to eject cyan ink.

In this example, a region designated by the reference numeral68in the medium transport direction is a second nozzle group68. The second nozzle group68faces a region between the second ribs52and the third ribs56in the medium transport direction, and includes a plurality of ink ejection nozzles capable of ejecting ink toward the region between the second ribs52and the third ribs56. As an example, the ink ejection nozzles of the second nozzle group68are configured to eject magenta ink.

Some ink ejection nozzles positioned on the transport direction-upstream side in the second nozzle group68are provided at a position facing the second guide surface54dof the second rib54in the medium transport direction. Some ink ejection nozzles positioned on the transport direction-downstream side in the second nozzle group68are provided at a position facing the upstream guide surface56cof the third rib56in the medium transport direction.

In this example, a region designated by the reference numeral70in the medium transport direction is a third nozzle group70. The third nozzle group70faces a region between the third ribs56and the fourth ribs58,60, and62in the medium transport direction, and includes a plurality of ink ejection nozzles capable of ejecting ink toward the region between the third ribs56and the fourth ribs58,60, and62. As an example, the ink ejection nozzles of the third nozzle group70are configured to eject yellow ink. Some ink ejection nozzles positioned on the transport direction-upstream side in the third nozzle group70are provided at a position facing the upper surface56bof the third rib56in the medium transport direction.

Furthermore, although not shown, in the lower surface of the recording head28, a plurality of ink ejection nozzles are arranged from the position Y1toward the position Y2in the medium transport direction, and the ink ejection nozzles are configured to eject black ink.

Regarding First Recording Mode and Second Recording Mode

In this example, the first recording mode and the second recording mode are recording modes used at the time of executing so-called a borderless printing in which recording is performed without leaving any margin in a medium for which recording is performed. In a case where the borderless printing is selected in recording operation on the medium, the control section46determines whether the edge portions of the medium in the medium width direction on which recording is performed are positioned within the first region W1or exceeds the first region W1, on the basis of input information from the operating section16, driver information, information from an external device, such as a PC, connected to the printer10, and the like. The control section46selects the first recording mode in a case where the edge portions of the medium in the medium width direction are positioned outside the first region W1, for example in a case of the medium P3(FIG. 5), and selects the second recording mode in a case where the edge portions of the medium in the medium width direction are positioned inside the first region W1, for example in a case of the medium P2(FIG. 5).

First, the first recording mode will be described. In the first recording mode, restrictions are imposed so that among the plurality of ink ejection nozzles provided in the second nozzle group68, only the ink ejection nozzles provided in a region designated by a reference numeral68-1eject inks, thereby executing recording operation. Specifically, the ink ejection region68-1faces a region between the transport direction-downstream side end portion54eof the second rib54and the upstream side end portion56aof the third rib56in the medium transport direction. The plurality of ink ejection nozzles provided on the ink ejection region68-1eject inks on the region between the transport direction-downstream side end portion54eof the second rib54and the upstream side end portion56aof the third rib56.

Here, in a case where ejection restrictions are not imposed on the second nozzle group68at the time of executing the borderless printing, when the trailing edge of the medium passes over the second rib54, some of the ink ejected toward the trailing edge of the medium may be adhered to the second guide surface54dand the like of the second rib54. In a case where a subsequent medium passes over the second rib54which is in a state where ejected ink is adhered, a back surface (a surface which is opposite a surface facing the recording head) of the subsequent medium may be stained with the ink adhered to the second rib54, thereby deteriorating a quality of the medium.

In this example, at the time of executing the borderless printing, by restricting an ink ejection region of the second nozzle group68to a region between the second rib54and the third rib56in the medium transport direction, it is possible to reduce adherence of ink to the second rib54. Accordingly, even at the time of executing the borderless printing on the medium of which positions of the edge portions in the medium width direction are positioned outside the first region, for example the medium P3(FIG. 5), it is possible to reduce a possibility that a back surface of the medium P3is stained with ink.

Furthermore, in this example, at the time of executing the first recording mode, even in the first nozzle group66and the third nozzle group70, an ink ejection region in the medium transport direction is restricted by control of the control section46. Specifically, in the first nozzle group66, the ink ejection region in the medium transport direction is restricted to a region designated by the reference numeral66-1. Similarly, in the third nozzle group70, the ink ejection region in the medium transport direction is restricted to a region designated by the reference numeral70-1.

In this example, a length of the ink ejection region66-1or70-1in the medium transport direction corresponds to a length of the ink ejection region68-1. More specifically, the number of ink ejection nozzles in the ink ejection region66-1or70-1matches the number of ink ejection nozzles in the ink ejection region68-1.

Referring toFIG. 10, recording operation on the medium P3in the first recording mode will be described. In an upper diagram ofFIG. 10, when the medium P3is transported from the transport direction-upstream side to a position facing the first nozzle group66of the recording head28, cyan ink is ejected from the ink ejection region66-1. In a middle diagram ofFIG. 10, after receiving the ink ejected from the ink ejection region66-1, the medium P3is sent to the transport direction-downstream side. When a portion P3C of the medium P3where the cyan ink is adhered is transported to a position facing the second nozzle group68, magenta ink is ejected from the ink ejection region68-1. Accordingly, the magenta ink is adhered on the cyan ink-adhered portion P3C of the medium P3.

Furthermore, in a lower diagram ofFIG. 10, after receiving the ink ejected from the ink ejection region68-1, the medium P3is sent to the transport direction-downstream side. When a portion P3M of the medium P3where the magenta ink is adhered on the cyan ink-adhered portion P3C is transported to a position facing the third nozzle group70, yellow ink is ejected from the ink ejection region70-1. Accordingly, a yellow ink-adhered portion P3Y of the medium P3is formed by adherence of the yellow ink on the magenta ink-adhered portion P3M which is adhered on the cyan ink-adhered portion P3C.

In this example, the number of ink ejection nozzles in the ink ejection regions66-1,68-1, and70-1in the medium transport direction matches with one another. Thus, lengths of ink-adhered portions formed by adherence of inks on the medium P3in the medium transport direction are substantially the same. As a result, at least cyan ink, magenta ink, and yellow ink are appropriately stacked on a region of the medium P3where inks are adhered. Thus, an appropriate recording result is formed on the medium P3.

Referring back toFIG. 9, the second recording mode will be described. In the second recording mode, restrictions are imposed so that among the plurality of ink ejection nozzles provided in the second nozzle group68, only the ink ejection nozzles provided in a region designated by a reference numeral68-2eject inks, thereby executing recording operation. Specifically, the ink ejection region68-2faces a region between the transport direction-downstream side end portion52eof the second rib52and the upstream side end portion56aof the third rib56in the medium transport direction. The plurality of ink ejection nozzles provided on the ink ejection region68-2eject inks on the region between the transport direction-downstream side end portion52eof the second rib52and the upstream side end portion56aof the third rib56.

In the medium transport direction, a length of the ink ejection region68-2of the second nozzle group68in the second recording mode is longer than the ink ejection region68-1of the second nozzle group68in the first recording mode. Specifically, the ink ejection region68-2is longer than the ink ejection region68-1by only a length of L4minus L3. Thus, the ink ejection region68-2has an increased number of the ink ejectable nozzles. As a result, in a case where a borderless printing is executed on the medium P2of which the edge portions in the medium width direction are positioned within the first region W1, recording can be executed by inks ejected from a larger number of ink ejection nozzles, thereby preventing a recording throughput from being lowered.

Even in the second recording mode, similar to the first recording mode, ejection restrictions are imposed so that the length of the ink ejection region of the first nozzle group66or the third nozzle group70corresponds to the length of the ink ejection region68-2of the second nozzle group68.

Control of Medium at Time of Performing Both-Surface Recording Operation

Next, referring toFIGS. 3, 4, and 11, control of the medium at the time of executing a both-surface recording operation will be described. Referring toFIGS. 3 and 4, when recording is executed on the first surface of the medium (surface that firstly faces the recording head at the time of being transported), the medium is sent out toward the driven roller38d, which is positioned at a lower side of the feed roller36, by reversely rotating the transport roller40. The medium sent to the driven roller38dis nipped by the feed roller36and the driven roller38d, and is returned back to the transport roller40by the feed roller36. At that time, the first surface of the medium (surface on which recording has been executed) and the second surface are reversed. Accordingly, recording is executed on the second surface in the recording head28.

Here, as shown inFIG. 11, after recording has been executed on the first surface of the medium, the control section46stops the transport to the transport direction-downstream side (forward feeding), as an example, at a position where the trailing edge P3F of the medium P3does not proceed to a downstream side from the third rib56, specifically, in a state where the trailing edge P3F is supported on the upper surface56bof the third rib56. Thereafter, the control section46sends the medium P3from the downstream side toward the upstream side in the medium transport direction (backward feeding) by reversely rotating the transport roller40, in which the trailing edge P3F of the medium P3becomes a head side.

In this example, the transport to the medium transport direction-downstream side (forward feeding) is stopped in a state where the trailing edge P3F of the medium P3is supported on the third rib56. Thus, compared to a case where the transport to the medium transport direction-downstream side (forward feeding) is stopped at a position where the trailing edge P3F of the medium P3has climbed over the third rib56, it is possible to reduce the ribs to be climbed over at the time of being fed backward and to reduce a risk of the trailing edge P3F getting caught in the rib. As a result, at the time of executing the both-surface recording operation on the medium in the printer10, it is possible to prevent jamming from occurring.

To summarize the above description, the printer10includes a recording head28which performs recording on the medium; the support member42which is disposed to face the recording head28and on which a plurality of ribs48,50,52,54,56,58,60, and62(FIG. 5) for supporting the medium are formed; the transport roller40provided on the upstream side of the support member42in the medium transport direction (Y axis direction); and the discharge roller44provided on the downstream side of the support member42in the medium transport direction. The plurality of ribs48,50,52,54,56,58,60, and62include the plurality of first ribs48and50(FIGS. 4 and 5) which are spaced apart from one another at an appropriate interval in the medium width direction (X axis direction) that is a direction intersecting with the medium transport direction, and the plurality of second ribs52and54(FIG. 5andFIG. 6) which are positioned on a downstream side from the first ribs48and50in the medium transport direction and are spaced apart from one another at an appropriate interval in the medium width direction. The second ribs52and54have the guide surfaces52dand54d(FIGS. 6A and 6B) for scooping up the leading edge of the medium which is fed backward from the downstream side to the upstream side in the medium transport direction, in which the guide surfaces52dand54dinclude the first guide surface52dwhich is formed on each of the second ribs52positioned within the first region W1(FIG. 5) in the medium width direction, and the second guide surface54dwhich is formed on the second rib54positioned in the second region W2positioned outside the first region W1in the medium width direction. The medium transport direction-downstream side end portion54eof the second guide surface54dis positioned on a downstream side from the medium transport direction-downstream side end portion52eof the first guide surface52dand has a lower height position h3than the height position h2for the medium transport direction-downstream side end portion52eof the first guide surface52d.

The borderless recording, for example, tends to be performed more frequently for a medium having a relatively small size such as an L-type photograph size than a medium having a relatively large size such as an A4 size. Therefore, prioritizing a throughput of the borderless recording for a medium having a small size over a throughput of the borderless recording for a medium having a large size is in line with users' needs.

Further, regarding the medium having a small size such as an L-type photograph size, for which the borderless recording is performed at a high frequency as described above, a dedicated paper is often used. In this case, because of a high paper stiffness (rigidity), hanging-down at the leading edge hardly occurs, that is, getting-caught of the medium leading edge in the rib at the time of being fed backward hardly occurs.

On the contrary, regarding the medium having a relatively large size such as an A4 size, a plain paper is often used. In this case, because of a low paper stiffness (rigidity), hanging-down at the leading edge easily occurs, that is, getting-caught of the medium leading edge in the rib at the time of being fed backward easily occurs. In addition, even in a case of having a somewhat strong paper stiffness (rigidity), influence of curls also becomes large as a size increases, and getting-caught of the medium leading edge in the rib at the time of being fed backward easily occurs. Therefore, it is reasonable to prioritize prevention of the medium having a large size from getting caught in the rib over prevention of the medium having a small size from getting caught in the rib, from the viewpoint of obtaining a good recording result as a whole.

In a configuration including the first ribs48and50(FIGS. 4 and 5) and the second ribs52and54(FIGS. 5, 6A, and 6B), the second ribs52and54(FIGS. 6A and 6B) have the guide surfaces52dand54d, respectively, for scooping up the leading edge of the medium which is fed backward from the downstream side to the upstream side in the medium transport direction. The guide surfaces52dand54dinclude the first guide surface52d(FIG. 6A) which is formed on each of the second ribs52positioned within the first region W1(FIG. 5) in the medium width direction, and the second guide surface54d(FIG. 6B) which is formed on each of the second ribs54positioned in the second region W2positioned outside the first region W1in the medium width direction, in which the medium transport direction-downstream side end portion54eof the second guide surface54dis positioned on a downstream side from the medium transport direction-downstream side end portion52eof the first guide surface52dand has a lower height position h3than the height position h2for the medium transport direction-downstream side end portion52eof the first guide surface52d.

That is, in the second region W2outside the first region W1, the second guide surface54dfor scooping up the medium leading edge is formed to be longer and from a lower side. Thus, the leading edge of the medium having a large size, for example, the medium P3, can be prevented from getting caught in the rib.

On the other hand, in the first region W1, the first guide surface52dfor scooping up the medium leading edge is shorter than the second guide surface54d. Thus, a region between the second rib52and the third rib56can be secured wide, and restrictions on the ink ejection nozzles at the time of performing the borderless recording can be loosened, thereby preventing a recording throughput from being lowered.

The printer10further includes a plurality of third ribs56(FIGS. 5, 6A, and 6B) which are positioned on a downstream side from the second ribs52and54in the medium transport direction and are spaced apart from one another at an appropriate interval in the medium width direction, in which the recording head28has the plurality of ink ejection nozzles along the medium transport direction (Y axis direction), and in which the recording apparatus is capable of executing the first recording mode, in which the ink ejection nozzles to be used are restricted to the ink ejection nozzles which are positioned within the range between the medium transport direction-downstream side end portion54eof the second guide surface54dand the upstream side end portion56aof each of the third ribs56in the medium transport direction, in a case where recording is performed on the medium P3of which the edge portions in the medium width direction (X axis direction) are positioned outside the first region W1(FIG. 5), and the second recording mode, in which the ink ejection nozzles are positioned within the range between the medium transport direction-downstream side end portion52eof the first guide surface52dand the upstream side end portion56aof each of the third ribs56in the medium transport direction and are used in a larger number than the ink ejection nozzles used in the first recording mode, in a case where recording is performed on the medium P2of which the edge portions in the medium width direction are positioned within the first region W1.

In the above configuration, by applying the second recording mode to the medium P2of which the width direction-edge portions are positioned within the first region W1, that is, the medium having a relatively small size, it is possible to use a larger number of ink ejection nozzles, thereby preventing a recording throughput from being lowered.

The printer10further includes a plurality of fourth ribs58,60, and62(FIGS. 7 and 8) which are positioned on a downstream side from the third ribs56in the medium transport direction and are spaced apart from one another at an appropriate interval in the medium width direction, in which the plurality of ink ejection nozzles are configured to include the first nozzle group66(FIG. 9) including the ink ejection nozzles which face a region between the first ribs48and50(FIGS. 4 and 5) and the second ribs52and54(FIGS. 5, 6A, and 6B) in the medium transport direction (Y axis direction), the second nozzle group68(FIG. 9) including the ink ejection nozzles which face a region between the second ribs52and54and the third ribs56(FIGS. 5, 6A, and 6B) in the medium transport direction, and the third nozzle group70including the ink ejection nozzles which face a region between the third ribs56and the fourth ribs58,60, and62(FIGS. 7 and 8) in the medium transport direction. In the first recording mode, use of the ink ejection nozzles constituting the second nozzle group68is restricted (ink ejection region68-1,FIG. 9), and the number of the ink ejection nozzles constituting the first nozzle group66or the third nozzle group70(ink ejection region66-1or70-1,FIG. 9) matches the number of the ink ejection nozzles used in the second nozzle group68.

In the above configuration, in a case where inks of different colors (cyan, magenta, and yellow) are ejected from the first nozzle group66, the second nozzle group68, and the third nozzle group70, and this is repeatedly done on the medium, an appropriate recording result can be obtained.

In the recording job in which recording is performed on both the first surface of the medium P3and the second surface opposite to the first surface, the control section46for controlling the transport roller40starts backward feeding of the medium P3at the position where the trailing edge P3F of the medium P3for which recording on the first surface has been completed does not proceed to a downstream side from the third ribs56. In this configuration, the medium trailing edge P3F does not need to climb over the third ribs56when the medium P3is fed backward, that is, it is possible to reduce the number of ribs over which the medium leading edge (trailing edge P3F) passes when the medium is fed backward, thereby suppressing a probability of jamming.

The plurality of fourth ribs58,60, and62(FIG. 8) provided along the medium width direction (X axis direction) are formed to have uneven heights. In this configuration, by adjusting the heights of the fourth ribs58,60, and62in response to the heights of the corrugation shaped valleys formed on the medium, it is possible to prevent the medium leading edge from colliding with the ribs and to realize a more appropriate transport of the medium.

The position of the medium transport direction-upstream side end portion52a(FIG. 6A) of each of the second ribs52positioned within the first region W1(FIG. 5) and the position of the medium transport direction-upstream side end portion54a(FIG. 6B) of each of the second ribs54positioned in the second region W2(FIG. 5) positioned outside the first region W1match at the position Y3. In this configuration, it is possible to allow the intervals between the first ribs48and50and the second ribs52and54in the medium transport direction (Y axis direction) to match with one another in the medium transport direction. As a result, regardless of a medium size, a region between the first ribs48and50and the second ribs52and54can be maximally used.

The ribs48,50,52,54,56,58,60, and62(FIG. 5) have the upstream guide surfaces48b(FIG. 4),50b(FIG. 4),52c(FIG. 6A),54c(FIG. 6B),58b(FIGS. 4 and 9),60b(FIG. 4), and62b(FIGS. 4 and 9) for scooping up the leading edge of the medium which is fed forward from the upstream side to the downstream side in the medium transport direction. In this configuration, when the medium is transported in the forward feeding direction, it is possible to prevent the medium leading edge from getting caught in the ribs48,50,52,54,56,58,60, and62.

The entire disclosure of Japanese Patent Application No. 2017-089390, filed Apr. 28, 2017 is expressly incorporated by reference herein.