JP4600059B2 - Platen and inkjet recording apparatus - Google Patents

Description

  The present invention relates to a platen used in an ink jet recording apparatus capable of recording an image without margins on a whole surface of a recording medium (for example, a recording paper) and capable of so-called borderless image recording, and an ink jet recording apparatus equipped with the platen.

  In an ink jet recording apparatus, an ink discharge surface of a recording head mounted on a carriage that can reciprocate in the main scanning direction is provided to face a recording surface of a recording sheet as a recording medium. A platen that defines the distance between the ink ejection surface and the recording surface of the recording paper is provided. An image is recorded by ejecting ink from the ink ejection surface while the recording paper is supported by the platen.

  Conventionally, in this type of ink jet recording apparatus, a device capable of so-called borderless image recording, in which an image is recorded on the entire surface of the recording paper by ejecting ink to an area larger than the recording surface of the recording paper, has been realized. Yes. As such an ink jet recording apparatus, for example, there is an ink jet recording apparatus described in Patent Document 1. In order to realize borderless image recording, the platen mounted in the ink jet recording apparatus is provided with a slot for discarding ink, and an ink absorbing member made of an elastic absorber is accommodated in the slot. Yes. Then, the ink abandoned for recording without margins on the edge of the recording paper is absorbed by the ink absorbing member housed in the slot provided in the platen. Therefore, the discarded ink does not adhere to the recording paper again or adheres to the next recording paper, so that the recording paper can be prevented from being damaged.

On the other hand, as described in Patent Document 2, there is proposed an ink jet recording apparatus that can perform borderless image recording without disposing an ink absorbing member in a portion on the platen facing the recordable area of the recording head. Has been. The ink jet recording apparatus includes a platen having a slope formed at a portion facing the recordable area of the recording head, and a waste ink absorber disposed below the slope. A plurality of ribs are formed on the inclined surface so as to extend in the recording paper conveyance direction, and are arranged at predetermined intervals in a direction intersecting the recording paper conveyance direction. Yes. In this defective portion, ink that is discarded during borderless image recording is ejected, and the discarded ink flows through the slope and is absorbed by the waste ink absorber.
JP 2002-86821 A Japanese Patent Laid-Open No. 2004-9407

  In general, in an ink jet recording apparatus, when a recording paper causes a paper jam (paper jam) in the apparatus or when an ink cartridge is replaced, a user opens the apparatus cover and puts a hand in the apparatus to work. become.

  However, in the platen described in Patent Document 1, since the ink absorbing member is accommodated in the slot provided on the upper surface of the platen, when the user opens the cover of the apparatus, the ink absorbing member is exposed. There is a possibility that the user's hand working directly touches the ink absorbing member that has become soiled over time, and the user's hand is soiled with ink.

  Further, when arranging the ink absorbing member, the upper surface of the ink absorbing member is arranged so as not to protrude above the upper end of the rib formed on the platen surface so that the upper surface of the ink absorbing member does not come into contact with the back surface of the recording paper to be conveyed There is a need to. For this purpose, the size and shape of the ink absorbing member must be strictly controlled and placed on the platen. However, an unstable material such as an elastic absorber used for the ink absorbing member has a size and shape. It takes time and effort to manage, and further, it takes time to install the ink absorbing member into the platen.

  Further, when fuzz occurs on the ink absorbing member, fibers stained with ink protrude from the slot of the platen, and this may come into contact with the back surface (non-recording surface) of the recording paper, which may cause the back surface of the recording paper to become dirty. There is.

  On the other hand, since the ink absorbing member is soiled by ink over time, when the user opens the cover of the apparatus, the dirty ink absorbing member housed in the slot of the platen is directly directed to the user. It will be visible. The fact that the area stained with ink is conspicuous is not pleasant for a user who has to put a hand in the apparatus to work. Therefore, in order not to give such unpleasant feeling to the user, it is necessary to make the ink absorbing member unnoticeable. As a countermeasure, a member such as black or dark gray is used as the ink absorbing member. Must be used. For this reason, there is a problem that the selection of the material of the ink absorbing member is restricted and the degree of freedom in design is reduced.

  On the other hand, in the platen described in Patent Document 2, a waste ink absorber is provided below the platen. Therefore, there is no possibility that the ink collected by the waste ink absorber adheres to the back surface of the recording paper and becomes dirty. Also, even if the user opens the device cover and puts his / her hand in the device, the user's hand is not likely to come into direct contact with the waste ink absorber, and the dirty waste ink absorber Is not directly visible to the user.

  However, in the platen described in Patent Document 2, since the waste ink absorber is disposed outside the platen, it is necessary to separately provide a case for storing the waste ink absorber, which increases the number of parts and reduces the cost. There is a problem that can not be. Further, since the ink absorbing member is disposed below the platen, it is difficult to reduce the height of the mechanism around the platen including the ink absorbing member. Therefore, when the size of the entire image recording apparatus is reduced. There is also a problem of becoming an obstacle.

SUMMARY An advantage of some aspects of the invention is to provide a platen having the following characteristics and an ink jet recording apparatus using the platen.
That is, when the user opens the cover of the apparatus and puts his / her hand in the apparatus to work, the hand does not touch the ink absorbing member and the hand is not stained with ink. The ink absorbing member does not come into contact with the recording paper and the back surface of the recording paper is not stained with ink. There is no need to increase the dimensional accuracy of the ink absorbing member. There is no need to separately provide a case for the ink absorbing member other than the platen. The degree of freedom in designing the material and shape of the ink absorbing member is improved. It is possible to reduce the size of the entire image recording apparatus.

The platen according to claim 1, which has been made to achieve the above object, is a recording head capable of recording an edgeless image with ink droplets on a recording medium transported along a predetermined direction in the ink jet recording apparatus main body. A platen that supports the lower surface of the recording medium below, an ink absorbing member that absorbs excess ink that has not landed on the recording medium among ink droplets ejected from the recording head during borderless image recording; A rib is provided to support the lower surface of the recording medium, and a platen main body on which the ink absorbing member is placed, and a platen cover disposed on the platen main body and covering the ink absorbing member from above. Further, the platen main body is located below the rib and is provided at a position facing the recordable area of the recording head at the time of borderless image recording. The ink receiving part receives excess ink, and the ink receiving part receives the ink receiving part. And an ink guide part that guides excess ink to an ink absorbing member positioned below the ink receiving part .

  In addition, as a raw material of a platen main body and a platen cover, a hard synthetic resin etc. are used, and it is preferable to be comprised by the member integrally molded, respectively. The ink absorbing member is preferably made of a material having good absorbability such as a porous material such as foamed polyurethane or a fibrous material such as paper or cloth. In addition, the ink guiding portion here refers to, for example, a groove that communicates from the ink receiving portion to the ink absorbing member on the platen main body, and guides ink by utilizing the inclination or capillary phenomenon in the groove, Any one that forms a slope and guides ink to an ink absorbing member disposed below the slope may be used.

  According to the platen configured in this manner, since the ink absorbing member for collecting excess ink discarded during borderless image recording is covered by the platen cover, the user opens the cover of the inkjet recording apparatus, The user's hand does not get in contact with the ink absorbing member stained with excess ink when the user puts his hand into the device to replace the ink cartridge or clear the paper jam. . Further, since the ink absorbing member is not directly visible to the user, it is not necessary to use an ink absorbing member made of a material that does not make the trace of absorbed ink conspicuous. Therefore, since a material having a high ink absorption capability can be used regardless of the color of the material, the performance is improved. Further, since the upper surface of the ink absorbing member is covered with the platen cover, the back surface of the recording medium (recording paper) does not come into contact with the ink absorbing member and become dirty.

Furthermore, since the height of the ink absorbing member is defined by the platen cover, the back surface of the recording paper does not contact the ink absorbing member even if the size and shape of the ink absorbing member vary. Therefore, it is not necessary to strictly manage the size and shape of the ink absorbing member, and it is not troublesome to incorporate the ink absorbing member. Further, since the ink absorbing member is arranged on the platen, it is not necessary to provide a separate case for arranging the ink absorbing member, which contributes to the reduction of the number of parts and the miniaturization of the entire image recording apparatus.
By the way, in order to realize high-quality recording in the ink jet recording apparatus, it is important to maintain an appropriate gap (also referred to as a gap between paper surfaces) between the ink ejection surface of the recording head and the recording surface of the recording paper. It is.
In contrast, in the first aspect of the present invention, the platen cover is covered on the upper surface of the platen cover so that the gap between the ink discharge surface of the recording head and the recording surface of the recording medium is maintained at an appropriate size. In addition to supporting the lower surface of the recording medium, a support portion formed continuously at a certain height in a direction orthogonal to the conveyance direction of the recording medium is provided, and the ink absorbing member is used for recording of the recording head on the platen body. It is also characterized by being arranged at a position other than the position facing the possible area.
Here, the support portion formed continuously at a certain height is, for example, a configuration that supports a recording sheet on a flat surface, or a configuration that supports a recording sheet on the top of a protruding streak-like ridge. Either may be used.
According to the platen configured in this way, the recording paper can be supported not only by the platen main body but also by the platen cover, so that the gap between the paper surfaces can be maintained more stably and the image quality can be maintained. It is possible to improve. In addition, even when the recording paper is easily bent due to the humidity or weight of the ink, such as when ink is ejected at a high density in order to perform high-quality recording, the surface and the ridges are constant. Since the recording paper is supported by the support portion continuously formed at a height of 1, the gap between the paper surfaces can be more stably maintained.

  Further, as in the platen according to claim 2, the ink guiding portion communicates with the ink absorbing member placement portion through the lower portion of the platen cover, so that the user can pass the ink guiding portion that passes under the platen cover. The hand and the back side of the recording paper are not touched, and there is no possibility of soiling them.

By the way, in the platen described in Patent Document 1, it is necessary to dispose the ink absorbing member immediately below the recordable area of the recording head in order to absorb the discarded ink. However, according to the configuration of the present invention, the ink receiving portion that receives the surplus ink ejected at the time of borderless image recording, and the ink guiding portion that guides the surplus ink received by the ink receiving portion to the ink absorbing member are provided. Thus, it is not necessary to dispose the ink absorbing member directly below the recordable area of the recording head. That is, as in the platen according to claim 3 , even if the ink absorbing member is disposed at a position other than the position facing the recordable area of the recording head on the platen main body, the excess ink discarded from the recording head is collected. It is possible. Therefore, in the platen of the present invention, the arrangement location of the ink absorbing member is not limited to the position immediately below the recordable area, and therefore the arrangement location of the ink absorbing member can be determined according to the design convenience. Accordingly, the degree of freedom in design with respect to the size and shape of the platen is improved, which can contribute to the downsizing of the entire image recording apparatus.

An ink jet recording apparatus according to a fourth aspect includes the platen according to any one of the first to third aspects. With such an ink jet recording apparatus, it is possible to realize an ink jet recording apparatus having the same effects as those of any one of the first to third aspects described above.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Overall Configuration of Inkjet Recording Apparatus 1]
FIG. 1 is a perspective view of an ink jet recording apparatus 1 according to an embodiment of the present invention.

  The ink jet recording apparatus 1 is a so-called multi function device (MFD) having a printer function, a copy function, a scanner function, a facsimile function, and the like, and has a sheet-like form such as paper or plastic film as a recording medium. Paper P is used.

  The ink jet recording apparatus 1 includes a paper feed cassette 3 that can be inserted into an opening 2a formed on the front side of a housing 2 made of synthetic resin. A paper discharge unit 10 for discharging recorded paper P in the direction of arrow A is provided above the paper feed cassette 3, and a paper discharge port communicating with the paper discharge unit 10 is provided on the front surface of the housing 2. It is provided in common above the opening 2a.

  The paper feed cassette 3 is configured to be capable of storing a plurality of sheets P cut into, for example, A4 size, letter size, legal size, postcard size, and the like. Each paper P is arranged such that its long side is parallel to the paper transport direction (sub-scanning direction or X-axis direction). Further, an auxiliary support member 3a that supports the rear end portion of the long sheet P of legal size or the like is attached to the front end of the paper feed cassette 3 so as to extend in the X-axis direction. When A4 size paper P stored in the paper feed cassette 3 is used, the auxiliary support member 3a can be stored in the front portion of the paper feed cassette 3 so as not to interfere with paper feed.

  On the other hand, on the upper part of the housing 2, an image reading device 12 used for reading a document in a copy function or a facsimile function is arranged. The image reading device 12 is configured to be vertically openable and closable with respect to one side end of the housing 2 via a pivot portion (not shown). Further, on the upper part of the image reading device 12, a document cover body 13 that covers the upper surface of the image reading device 12 is mounted so as to be vertically rotatable around a pivot (not shown) provided at the rear end of the image reading device 12. Yes.

  When reading an image, the document cover 13 is opened upward and the document is placed on the placement glass plate, and reciprocates in the Y-axis direction (main scanning direction) below the placement glass plate. An image on the original paper surface is read by scanning a movable contact image sensor (CIS: Contact Image Sensor) provided on the original paper surface.

  An operation panel unit 14 including various operation buttons, a liquid crystal display unit, and the like is provided in front of the document cover 13 on the upper surface of the image reading device 12. An external memory insertion portion 11 for inserting an external memory is provided below the operation panel portion 14 on the front surface of the housing 2. The external memory here is, for example, CompactFlash (registered trademark), SmartMedia (registered trademark), Memory Stick (registered trademark), SD card (registered trademark), xD (registered trademark), or the like.

FIG. 2 is a perspective view showing an internal configuration of the housing 2 positioned below the image reading device 12.
As shown in FIG. 2, an ink jet recording head 4 (see FIGS. 4 and 5) for realizing a printer function is mounted inside the housing 2, and can be reciprocated in the Y-axis direction (main scanning direction). A recording unit 7 including a carriage 5 and other mechanisms is provided. A detailed description of the recording unit 7 will be described later.

  In addition, an ink storage portion 15 that is open toward the top of the housing 2 is provided at a front portion inside the housing 2. In the ink storage unit 15, ink cartridges 19 each storing inks of four colors (black, cyan, magenta, and yellow) for full color recording are stored in a line along the X-axis direction. Further, the ink cartridge 19 is configured to be detachable from the ink storage unit 15 from above. When the ink is replenished, the ink cartridge 19 is replaced. When the ink cartridge 19 is replaced, the above-described image reading device 12 is opened upward, and a work is performed by putting a hand into the opened housing 2.

  The ink stored in each ink cartridge 19 is configured to be supplied to the recording head 4 via four ink supply pipes 20 that connect each ink cartridge 19 and the recording head 4. In addition, when using a larger number of ink colors (6 colors or 8 colors) than four colors, the number of ink cartridges corresponding to the number of ink colors can be stored in the ink storage unit 15 and What is necessary is just to increase the supply pipe | tube 20 according to the number of ink cartridges. One end of each ink supply tube 20 is connected to a connecting portion 5 a in a connecting piece at the base of the carriage 5.

  The other end portion of the ink supply tube 20 is bundled at a portion of one end portion 15 a of the ink storage portion 15, and extends along the Y-axis direction on the upper surface of the lower cover body 29. The ink supply tube 20 is supported by the upper surface of the lower cover body 29 and the vertical partition plate 32 provided on the lower cover body 29 and the fixed body 33 so as to be able to follow the reciprocating movement of the carriage 5.

  A belt-like flexible flat cable 36 for transmitting a command signal for selectively ejecting ink droplets from the nozzles of the recording head 4 mounted on the carriage 5 from a control unit (not shown) is 5 is arranged so as to be able to follow the reciprocating movement of the carriage 5.

FIG. 3 is a plan view of the recording unit 7.
The recording unit 7 is supported by a pair of left and right side plates 21a constituting a main frame 21 made of a metal plate or the like, and extends in the Y-axis direction (main scanning direction). A carriage 5 mounted across the guide members 22 and 23 and configured to be reciprocally movable in the main scanning direction, an ink jet recording head 4 (see FIGS. 4 and 5) mounted on the carriage 5, and the carriage 5. A timing belt 24 for transmitting power for reciprocating movement, a carriage motor 25 (see FIG. 2) for driving the carriage 5 via the timing belt 24, and the conveyed paper P under the recording head. A substantially flat plate-like platen 26 to be supported and a Y-axis direction (main scanning direction) position of the carriage 5 arranged so as to extend along the Y-axis direction (main scanning direction). Comprising an encoder strip and other mechanisms such as for knowledge.

  The carriage 5 scans the recording head 4 by reciprocating in the Y direction (main scanning direction) under the control of a control unit (not shown) including a CPU or the like. The recording head 4 records an image on the paper P stopped and disposed below the recording head 4 by ejecting ink during this scanning. At this time, the paper P is supported by the platen 26 constituting the transport path. That is, the recording head 4 is positioned immediately above the platen 26, and image recording onto the paper P by the recording head 4 is performed above the platen 26.

  A waste ink receiver 34 that receives ink discharged during the flushing operation performed by the recording head 4 is formed at a position corresponding to the outside of the sheet P conveyance region at the left end portion of the platen 26. A maintenance unit 35 is supported and mounted by guide members 22 and 23 at a position corresponding to the standby position of the carriage 5 on the right side of the platen 26. The recording head 4 periodically performs ink discharge (flushing) for preventing nozzle clogging during a recording operation above the waste ink receiver 34, and the waste ink receiver 34 receives the discharged waste ink. On the other hand, in the maintenance unit 35, the nozzle surface of the recording head 4 is cleaned, ink of each color is selectively sucked, and recovery processing for removing bubbles in a buffer tank (not shown) on the recording head 4 is performed. Etc.

  Note that a nozzle array composed of a plurality of nozzles extends along the X-axis direction on the nozzle surface (lower surface) of the recording head 4, and nozzle arrays provided for each ink color are formed at appropriate intervals in the Y-axis direction. Yes. In the embodiment, there are four nozzle rows respectively corresponding to the four ink colors, and the nozzle arrangement interval in each nozzle row is 75 dpi in the embodiment.

4 is a sectional side view taken along line XX in FIG. 3 (that is, a sectional view of the recording unit 7), and FIG. 5 is an enlarged sectional view of a main part of FIG.
As shown in FIG. 4, on the rear side of the paper feed cassette 3, a bank portion 8 that is an inclined separation plate for paper separation is disposed. Further, an arm 6 a having a sheet feeding roller 6 for feeding sheets at the lower end is provided above the sheet feeding cassette 3. The arm 6a is mounted so as to be rotatable in the vertical direction about the upper end portion thereof.

  In the above configuration, when a control unit (not shown) receives an image recording command, the paper feed roller 6 is driven to rotate by the operation of a drive motor (not shown), and the top of the paper P accumulated in the paper feed cassette 3 is driven. A plurality of sheets P including those at the position are fed to the rear of the sheet feeding cassette 3 (rightward in FIG. 4). The plurality of sheets P fed by the sheet feeding roller 6 are separated into one sheet by the inclined surface of the bank portion 8 for sheet separation. The separated paper P is fed to a recording unit 7 provided above the paper feed cassette 3 through a U-turn path 9 that is a feed path that faces upward.

  On the other hand, as shown in FIG. 5, a registration roller pair 27 is arranged on the recording unit 7 on the upstream side of the platen 26 in the paper conveyance direction, and on the further upstream side, a lever for detecting the leading edge of the paper P 55 is provided. While the paper P separated by the bank 8 is being fed to the position of the registration roller pair 27 via the U-turn path 9, the leading edge of the paper P pushes the lever 55 away, and a sensor (not shown) The tip is detected, and a tip detection signal is transmitted from this sensor to the control unit. The control unit is configured to transmit an ink ejection command for ejecting ink from the nozzles of the recording head 4 after the elapse of a predetermined time after detecting the leading edge of the paper P by receiving this detection signal.

  The sheet P conveyed to the registration roller pair 27 is sent to the lower side of the recording head 4 by the registration roller pair 27 while being supported by the platen 26 from below. Then, recording is performed on the paper P by ejecting ink from the recording head 4 based on the ejection command from the control unit. Spur rollers 28a and 56 that are in contact with the upper surface of the paper P and paper discharge rollers 28b that are in contact with the lower surface are disposed on the downstream side of the platen 26 in the paper conveyance direction (arrow A direction), and the recorded paper P is a spur roller 28a. And the paper discharge rollers 28b and 56 to the paper discharge unit 10.

  The ink jet recording apparatus 1 according to the present embodiment includes a mode in which image recording (marginless image recording) can be performed without a margin from the leading edge to the trailing edge of the paper P conveyed in the direction of arrow A shown in each drawing. Yes. The ink jet recording apparatus 1 of the present embodiment is configured to be able to selectively execute the borderless image recording mode and the bordered image recording mode according to a selection command from a user. This borderless image recording realizes borderless image recording by ejecting ink in a range larger than the recording surface of the paper P, and the ink that has not adhered to the recording surface of the paper P is discarded as excess ink. (Collected).

[Configuration of Platen 26]
Next, the configuration of the platen 26 of the present embodiment will be described in detail.
As shown in the perspective view of the platen 26 in FIG. 7, the platen 26 includes a platen main body 26a that is a box-shaped synthetic resin molded product having a substantially rectangular shape in plan view, and a sheet conveyance direction (arrow A direction) downstream of the upper surface of the platen main body 26a. A platen cover 46, which is a flat-plate synthetic resin molded product having a substantially rectangular shape in plan view, attached so as to cover the side along the Y-axis direction, is placed on the upper surface of the platen main body 26a, and the upper surface of the platen main body 26a is It is composed of an ink absorbing member 53 (see FIG. 9B) housed in an internal space on the platen main body 26a formed by being covered by the platen cover 46.

  8A and 8B are diagrams showing the platen main body 26a in a state where the platen cover 46 and the ink absorbing member 53 are removed from the platen 26, in which FIG. 8A is a perspective view and FIG. FIG.

  The platen main body 26a includes a flat shelf 40 that is disposed upstream of the paper conveyance direction (arrow A direction) and faces the back surface of the paper P. On the upstream side in the sheet conveying direction of the shelf plate portion 40 that is long in the Y-axis direction, a concave plate portion 42 that is open upward and has a U-shaped cross-section is connected.

  In addition, an ink receiving portion 43 is connected to a downstream end portion of the shelf plate portion 40 in the sheet conveyance direction at a position relatively lower than the shelf plate portion 40. This ink receiving portion 43 is for receiving excess ink ejected from the recording head 4 during borderless image recording, and is used for borderless image recording area G2 (shown in FIG. And a width corresponding to the width in the X-axis direction, and is inclined downward toward the downstream side in the paper conveyance direction.

  On the downstream side of the ink receiving portion 43 in the paper conveyance direction, there is a concave plate-like placement portion 45 on which an ink absorbing member 53 for absorbing excess ink ejected during borderless image recording is placed. It is provided at a position relatively lower than the receiving portion 43. The ink receiving portion 43 and the placement portion 45 are connected to each other via a wall surface portion 44 formed downward from the downstream end portion of the ink receiving portion 43 in the sheet conveyance direction.

  In addition, side frames 48 that are integrally formed at both ends in the Y-axis direction (main scanning direction) of the shelf plate portion 40, the concave plate portion 42, the ink receiving portion 43, the wall surface portion 44, and the placement portion 45 are provided. Yes. The waste ink receiver 34 is integrally formed on the side of the left side frame 48.

  On the shelf plate portion 40 and the concave plate portion 42, a plurality of upstream ribs 41 that are long along the X-axis direction and are formed at appropriate intervals in the Y-axis direction are provided. The upstream rib 41 supports the sheet P conveyed on the platen 26 from below. The upstream rib 41 connects the shelf 40 and the ink receiver 43 from the upstream end of the concave plate 42 in the sheet conveying direction. Part (that is, the downstream end of the shelf board 40).

  On the other hand, the ink receiving portion 43 includes a first rib 49 and a second rib 50 that are a plurality of types of ribs for supporting the front end portion and the rear end portion of the paper P, respectively, in the paper transport direction (X-axis direction). It is provided so that it may extend along.

  The first rib 49 is formed so as to project on the extension line in the paper conveyance direction of each upstream rib 41 on the upper surface of the ink receiving portion 43, and is inclined upward toward the downstream side in the paper conveyance direction. Further, the first rib 49 starts from a connecting portion of the shelf board portion 40 and the ink receiving portion 43 (that is, the upstream end portion of the ink receiving portion 43 in the paper transport direction) and downstream of the ink receiving portion 43 in the paper transport direction. The uppermost portion is formed at the end portion, and extends downward along the wall surface portion 44 from there to the lower end of the wall surface portion 44.

  The second rib 50 is provided so as to be positioned between the first ribs 49 provided in parallel in the Y-axis direction, and the upper end surface of the second rib 50 is horizontal on the upper surface of the ink receiving portion 43. It is formed to protrude. Further, the height position of the upper end surface of the second rib 50 is formed lower than that of the first rib 49. Similarly to the first rib, the second rib 50 starts from the connecting portion of the shelf board portion 40 and the ink receiving portion 43 (that is, the upstream end portion of the ink receiving portion 43 in the paper transport direction). The uppermost portion is formed at the downstream end portion in the sheet conveyance direction, and extends downward along the wall surface portion 44 from there to the lower end of the wall surface portion 44.

  On the upper surface and the wall surface 44 of the ink receiving portion 43 and the placement portion 45, an upward open V groove 51 having a V-shaped cross section having a rounded shape on the bottom surface extending along the paper conveyance direction is provided in the Y-axis direction ( Many are formed in parallel over the entire area (main scanning direction). The V-groove 51 corresponds to an ink guiding portion in claims, and causes the ink absorbing member 53 to circulate the surplus ink ejected during borderless image recording and received by the ink receiving member 53 to the mounting portion 45. This is an ink flow path. The V-groove 51 starts from a connecting portion of the ink receiving portion 43 with the shelf plate portion 40 (that is, an upstream end portion in the paper transport direction of the ink receiving portion 43), passes through the wall surface portion 44, and transports the paper of the mounting portion 45. It communicates to the vicinity of the downstream end of the direction.

  A plate-like positioning projection 54 for positioning and supporting the ink absorbing member 53 is formed at an appropriate interval in the Y-axis direction on the upstream side of the placement unit 45 in the paper conveyance direction. The ink absorbing member 53 is placed on almost the entire surface downstream of the positioning projection 54 on the placement portion 45, and is not displaced by the wall surface of the positioning projection 54 and the end portion of the placement portion 45 on the downstream side in the sheet conveyance direction. Supported by The details of the arrangement state of the ink absorbing member 53 will be described later.

  9A and 9B are diagrams showing the platen cover 46, in which FIG. 9A is a perspective view of the platen cover 46, and FIG. 9B is a cross-sectional side view taken along the C plane in FIG. For convenience of explanation, (b) shows a cross section of the platen main body 26a and the ink absorbing member 53 in a state where the platen cover 46 is mounted on the platen main body 26a.

  As described above, the platen cover 46 is a flat synthetic resin molded product having a substantially rectangular shape in plan view and is attached so as to cover the downstream side of the upper surface of the platen main body 26a in the paper conveyance direction (arrow A direction) along the Y-axis direction. Yes, and attached so as to cover the upper part of the ink absorbing member 53 placed on the placement portion 45 of the platen main body 26a. As shown in FIG. 9, the platen cover 46 includes a side wall portion 46 a, a ridge support portion 46 b, a planar support portion 46 c, and a claw portion 47.

The side wall portion 46 a is a wall surface formed substantially perpendicular to the upstream end portion of the platen cover 46 in the sheet conveyance direction shown in the arrow A direction.
The protrusion support portion 46b has a triangular protrusion in the side view formed of an upwardly inclined surface and a downwardly inclined surface subsequent to the downstream side in the sheet conveying direction at the upper end of the side wall portion 46a along the Y-axis direction (main scanning direction). In order to support the sheet P conveyed on the platen 26 from below, the sheet P is formed continuously.

  The planar support portion 46c is composed of a plane that is gently inclined upward from the ridge support portion 46b toward the downstream side in the sheet conveyance direction and a substantially horizontal plane. The planar support portion 46c covers the ink absorbing member 53 from above, and further includes a platen. The paper P conveyed on the top 26 is supported from below.

  The claw portion 47 is a tongue-like small piece formed so as to extend laterally from both ends in the Y-axis direction (main scanning direction) of the planar support portion 46c. The claw portion 47 is on the side of the platen main body 26a. By engaging with the frame 48, the platen cover 46 is supported by the platen body 26a and attached to the platen body 26a. At this time, a space for accommodating the ink absorbing member 53 is formed between the lower surface of the platen cover 46 and the upper surface of the mounting portion 45. Further, the V-groove 51 formed on the upper surface of the mounting portion 45 communicates from the upstream side in the paper transport direction to the ink absorbing member 53 on the downstream side in the paper transport direction through the lower side of the side wall portion 46a. Yes.

  The platen cover 46 configured as described above not only functions as a cover for covering the ink absorbing member 53 but also lowers the sheet P conveyed on the platen 26 by the ridge support portion 46b and the planar support portion 46c. It also has the function to support from.

Here, with reference to FIG. 6 which is an enlarged cross-sectional view of the periphery of the platen 26 in the recording unit 7, the functions of the platen 26 and its peripheral mechanisms during image recording will be described in detail.
The bordered image recording area G1 is a recordable range when all the nozzles (75 in this embodiment) arranged in the X-axis direction of the recording head 4 eject ink. The bordered image recording area G1 is set in a range from the midway portion of the upstream rib 41 in the sheet conveyance direction to the side wall portion 46a of the platen cover 46.

  The borderless image recording area G2 is a recordable range when the nozzles at the downstream end of the recording head 4 in the paper transport direction are the first nozzles and the seventh to 28th nozzles eject ink toward the upstream in the paper transport direction. It is. The borderless image recording area G2 is set in a range from the upstream end of the ink receiving portion 43 in the sheet conveying direction to the uppermost point 49a of the first rib 49 formed on the ink receiving portion 43.

  When the first to sixth nozzles eject ink between the edge of the edge-recording image recording area G1 on the downstream side in the sheet conveyance direction and the edge of the edge-less image recording area G2 on the downstream side in the sheet conveyance direction. A margin area G3 corresponding to the recordable range is set.

  In the bordered image recording mode, ink is ejected from 75 nozzles corresponding to the bordered image recording area G1 to the paper P that is intermittently conveyed in the direction of the arrow A, and predetermined image recording is performed. In the bordered image recording mode, ink is not ejected from the top, bottom, left, and right edges of the paper P to a predetermined dimension (for example, 3 mm to 5 mm), resulting in a blank portion.

  Accordingly, ink ejection in the bordered image recording mode is started at the following timing. That is, while the paper P is being transported on the platen 26 in the direction of arrow A, the leading edge of the paper P protrudes by a distance corresponding to the size of the margin portion downstream of the bordered image recording region G1 in the paper transport direction. When the ink reaches a position where ink is discharged, ink discharge is started. At this time, the vicinity of the front end portion of the paper P is supported by the uppermost point 49 a of the first rib 49.

  Then, the portion of the sheet P on which image recording is completed is sequentially sent downstream in the sheet conveying direction. At this time, the protrusion support portion 46b and the planar support portion 46c formed on the upper surface of the platen cover 46 are moved to the ink. By supporting the paper P, which has become heavier with the load, from below, the gap between the upper surface of the paper P and the nozzle surface can be maintained at an appropriate size. In the embodiment, the gap is about 1.76 mm. If the gap is too large, the ink droplets ejected from the nozzles are scattered in the air, and a good image quality cannot be obtained. On the other hand, if the gap is too small, the upper surface of the paper P comes into sliding contact with the nozzle surface, resulting in recording failure.

  Regarding the end of ink ejection, recording is performed after ink ejection is completed at a position where the trailing edge of the paper P is left by a distance corresponding to the size of the margin on the upstream side in the paper conveyance direction of the image recording area G1 with a border. Ends.

  Then, the sheet P on which recording has been completed is sent between the spur roller 28a and the sheet discharge roller 28b on the downstream side in the sheet conveyance direction while being supported by the ridge support part 46b and the sheet-like support part 46c of the platen cover 46. The paper is discharged to the paper unit 10. If the leading edge of the paper P is lifted when the paper P after image recording is transported downstream in the paper transport direction, the paper P will reach before the downstream discharge roller 28b and spur roller 28a. Since paper jam is likely to occur, the spur roller 56 prevents the leading edge of the paper P from being lifted.

  On the other hand, in the borderless image recording mode, ink is ejected from the 22 (seventh to 28th) nozzles corresponding to the borderless image recording area G2, and an image is recorded without margins on the edge of the paper P. I do.

  Accordingly, ink ejection in the borderless image recording mode is started at the following timing. That is, while the sheet P is fed from the upstream side in the sheet conveyance direction and is conveyed in the direction of the arrow A while being supported by the upstream rib 41 on the platen 26, the leading edge of the sheet P has an edgeless image recording region G2. At the time of entering, the ink discharge is started from the nozzle corresponding to the borderless image recording region G2 of the recording head 4. Here, the borderless image recording is performed in which the margin is recorded on the edge portion of the sheet P by ejecting ink outside the range of the recording surface of the sheet P in the marginless image recording region G2. ing. That is, since ink is ejected from the nozzle located downstream of the leading edge of the paper P in the paper transport direction, excess ink that does not fall on the leading edge of the paper P is formed on the upper surface of the ink receiving portion 43. It adheres to the rib 49, the second rib 50 and the V-groove 51. Here, the heights of the upper end surfaces of the first rib 49 and the second rib 50 are lower than the height of the upper end surface of the upstream rib 41 (see FIG. 8B), and the sheet P is on the upstream side. By being supported by the rib 41, the back surface of the leading end of the paper P does not contact the upper end surface of the in-region rib. Therefore, excess ink attached to the first rib 49 and the second rib 50 does not adhere to the back surface of the paper P.

  Then, image recording on the paper P progresses, and the rear edge of the paper P enters the borderless image recording area G2 while the rear portion of the paper P is supported by the ridge support portion 46b of the platen cover 46. In addition, in a state where the rear end edge is supported by the uppermost point 49a of the first rib 49, edgeless image recording is performed on the rear end edge. Also in this case, since ink is ejected outside the recording surface range of the paper P in the borderless image recording region G2, recording is performed without margin on the edge of the paper P. Ink is also ejected from nozzles located upstream of the edge in the paper transport direction. Excess ink that does not fall on the trailing edge of the paper P adheres to the first rib 49, the second rib 50, and the V groove 51 formed on the upper surface of the ink receiving portion 43.

  The excess ink that has fallen on the ink receiving portion 43 travels along the slope of the V-groove 51 and gathers at the bottom of the V-groove 51, and the V-groove 51 is caused by the action of capillary action due to the inclination of the ink receiving portion 43 and the wall surface of the V-groove. Along the sheet transport direction downstream in the paper transport direction and reach the placement unit 45. Then, the ink is collected by being absorbed by the ink absorbing member 53 placed on the placement portion 45.

  10A and 10B are views showing the arrangement of the ink absorbing member 53 in the placement portion 45 of the platen main body 26a. FIG. 10A is a partially enlarged plan view, and FIG. 10B is a sectional view taken in the direction of arrow D in FIG. (C) is the E direction arrow directional cross-sectional view of (a).

  The ink absorbing member 53 is a flat plate member made of a material having high absorbability such as a porous material such as foamed polyurethane or a fibrous material such as paper or cloth. The ink absorbing member 53 has substantially the same width as the width in the Y-axis direction (main scanning direction) of the placement portion 45 of the platen main body, and is placed on the placement portion 45 as shown in FIG. Is done. At this time, the ink absorbing member 53 has a positioning protrusion 54 provided slightly downstream from the upstream end of the loading portion 45 in the paper conveyance direction (arrow A direction) and the downstream end of the loading portion 45 in the paper conveyance direction. Is supported by the wall surface so as not to be displaced in the X-axis direction. The height of the ink absorbing member 53 is set so as not to contact the lower surface of the platen cover 46. In FIG. 10A, in order to show the state of the V-groove 51 formed on the upper surface of the mounting portion 45, a part of the ink absorbing member 53 (near the right end of the drawing) is shown broken away. However, the ink absorbing member 53 actually exists up to the right end portion of the placement portion 45.

  The V-groove 51 formed on the upper surface of the mounting portion 45 communicates with the downstream end of the ink absorbing member 53 in the sheet conveying direction along the lower surface of the ink absorbing member 53. In other words, the ink absorbing member 53 is placed on the upper part of the parallel V-groove 51 group (see FIGS. 10B and 10C).

  Excess ink that has fallen on the ink receiving portion 43 travels along the slope of the V-groove 51 and gathers at the bottom of the V-groove 51, and along the V-groove 51 due to the inclination of the ink receiving portion 43 and capillary action due to the wall surface of the V-groove. The paper then flows downstream in the paper transport direction and reaches the placement unit 45. Here, since the V-groove 51 communicates with the downstream end of the ink absorbing member 53 along the lower surface of the ink absorbing member 53 in the paper conveyance direction, the excess ink flows through the V groove 51 and the ink absorbing member. 53 is reachable over the entire region below. The surplus ink is collected by being absorbed from the lower surface of the ink absorbing member 53.

[effect]
According to the ink jet recording apparatus 1 of the present embodiment, the following effects can be obtained.
(1) Since the ink absorbing member 53 for collecting excess ink discarded during borderless image recording is covered with the platen cover 46, the user opens the image reading device 12 of the inkjet recording apparatus 1, and the device The user's hand does not touch the ink absorbing member 53 that is soiled with excess ink when the user puts the hand into the container and replaces the ink cartridge 19 or clears a paper jam. Absent. In addition, since the ink absorbing member 53 is not directly visible to the user, it is not necessary to use a material that does not make the trace of the ink absorbed into the material of the ink absorbing member 53 noticeable. Therefore, since a material having a high ink absorption capability can be used regardless of the color of the material, the performance is improved. Further, since the upper surface of the ink absorbing member 53 is covered by the platen cover 46, the back surface of the paper P does not come into contact with the ink absorbing member 53 and become dirty.

  (2) Since the height of the ink absorbing member 53 is defined by the platen cover 46, the back surface of the paper P does not contact the ink absorbing member 53 even if the size and shape of the ink absorbing member 53 vary. . Therefore, it is not necessary to strictly manage the size and shape of the ink absorbing member 53, and it is not troublesome to incorporate the ink absorbing member 53. In addition, since the ink absorbing member 53 can be easily enlarged and more ink can be absorbed, the replacement interval of the ink absorbing member 53 becomes longer and maintenance is easy. Further, since the ink absorbing member 53 is arranged on the platen, it is not necessary to provide a separate case for arranging the ink absorbing member, which contributes to a reduction in the number of components and a reduction in the size of the entire image recording apparatus.

  (3) By supporting the paper P on which the image is recorded by the ridge support portion 46b and the planar support portion 46c formed on the platen cover 46, the gap between the paper surfaces can be maintained more stably, and the image quality is improved. It is possible to improve. In addition, even when the paper P is easily bent due to the humidity or weight of the ink as in the case of ejecting ink at a high density in order to perform high-quality recording, the surface and protrusions are constant. Since the paper P is supported by the support portion that is continuously formed at the height, the gap between the paper surfaces can be more stably maintained.

  (4) The platen main body 26a is integrally formed with the mounting portion 45 for mounting the ink absorbing member 53, and is disposed outside the recordable area of the recording head 4, so that the platen has a thin shape. 26 is realized. As a result, the space in the apparatus can be saved and the inkjet recording apparatus 1 can be made thinner.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-described embodiments, and can be implemented in various modes as long as they belong to the technical scope of the present invention. It is.

  For example, depending on the design convenience such as the space in the image recording apparatus and the positional relationship with other mechanisms, the mounting portion 45 of the platen main body 26a may be positioned upstream of the recordable range of the recording head 4 in the sheet conveying direction. You may form in various positions, such as the downward direction of a recordable range, and a side.

1 is a perspective view of an ink jet recording apparatus according to an embodiment. FIG. 2 is a perspective view illustrating a configuration around a recording unit in the ink jet recording apparatus according to the embodiment. It is a top view of a recording part. It is sectional drawing of a recording part. It is a partially expanded sectional view of a recording part. It is an expanded sectional view around the platen of the recording unit. It is a perspective view of the platen of an embodiment. It is the perspective view and sectional drawing of a platen main body. It is the perspective view and sectional drawing of a platen cover. It is a figure which shows the arrangement | positioning condition of the ink absorption member on a platen, (a) is a partially expanded plan view, (b) is D direction arrow sectional drawing of (a), (c) is E direction of (a). It is arrow sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inkjet recording apparatus, 2 ... Housing, 2a ... Opening part, 3 ... Paper feed cassette, 3a ... Auxiliary support member, 4 ... Recording head, 5 ... Carriage, 5a ... Connection part, 6 ... Paper feed roller, 6a ... Arm , 7 ... recording section, 8 ... bank section, 9 ... U-turn path, 10 ... paper discharge section, 11 ... external memory insertion section, 12 ... image reading device, 13 ... document cover body, 14 ... operation panel section, 15 ... ink Storage part, 15a ... one end, 19 ... ink cartridge, 20 ... ink supply pipe, 21 ... main frame, 21a ... side plate, 22, 23 ... guide member, 24 ... timing belt, 25 ... carriage motor, 26 ... platen, 26a ... Platen main body, 27 ... Registration roller pair, 28a, 56 ... Spur roller, 28b ... Paper discharge roller, 29 ... Cover body, 32 ... Vertical partition plate, 33 ... Fixed body, 34 ... Waste 35 ... maintenance unit, 36 ... flexible flat cable, 40 ... shelf plate portion, 41 ... upstream rib, 42 ... concave plate portion, 43 ... ink receiving portion, 44 ... wall surface portion, 45 ... mounting portion, 46 ... Platen cover, 46a ... Side wall part, 46b ... Projection support part, 46c ... Planar support part, 47 ... Claw part, 48 ... Side frame, 49 ... First rib, 50 ... Second rib, 51 ... V groove, 53 ... Ink absorbing member, 54 ... Positioning protrusion, 55 ... Lever, G1 ... Image recording area with margin, G2 ... Image recording area without margin, G3 ... Margin area, P ... Paper

Claims (4)

A platen that supports the lower surface of the recording medium below a recording head capable of recording an edgeless image with ink droplets on the recording medium conveyed along a predetermined direction in the ink jet recording apparatus main body,
An ink absorbing member that absorbs excess ink that has not landed on the recording medium among ink droplets ejected from the recording head during borderless image recording;
A platen main body provided with a rib for supporting the lower surface of the recording medium, and on which the ink absorbing member is placed;
A platen cover disposed on the platen body and covering the ink absorbing member from above;
The platen body is
An ink receiving portion that is positioned below the rib and that faces the recordable area of the recording head during borderless image recording and receives the excess ink, and the excess ink received by the ink receiving portion An ink guiding portion for guiding the ink absorbing member positioned below the ink receiving portion,
The platen cover is
To the platen cover the upper surface, to support the lower surface of the recording medium to maintain a gap between the ink discharge surface and the recording surface of the recording medium of the recording head to the appropriate size, the object
A platen comprising: a support portion continuously formed at a certain height in a direction orthogonal to a conveyance direction of a recording medium . The platen of claim 1,
The platen characterized in that the ink guide part communicates with an arrangement position of the ink absorbing member through a lower part of the platen cover. The platen according to claim 1 or 2,
The platen according to claim 1, wherein the ink absorbing member is disposed at a position other than a position facing the recordable area of the recording head on the platen main body. An ink jet recording apparatus comprising the platen according to any one of claims 1 to 3.