Abstract:
A recording device includes a guide protruding from and retracting toward a platen and a discharge support protruding from and retracting toward the guide. With this arrangement, the process for fabricating the parts of the device is not complicated, a large space for the discharge support is not needed, and a required flatness of the upper surface of the platen is easily obtained even when the device includes the discharge support.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a recording device having a transport mechanism for transporting a recording medium such as a sheet of paper on which a recording head performs recording. 
     2. Description of the Related Art 
     In general, ink-jet recording devices perform recording on a recording medium by allowing a recording head to discharge flying ink drops. Such recording devices have various advantages such as an easy reduction in the size of the recording head, performing accurate and high-speed recording, a low running cost, low noise due to non-impact features, and easy forming of a color image by using a variety of color inks. 
     In such an ink-jet recording device, a recording sheet on which the recording head has performed recording is held by a platen in a recording area and is discharged by a discharge section disposed downstream in the transport direction of the recording sheet. 
     With reference to FIGS. 14 to  17 , a known ink-jet recording device will be described. FIG. 14 is a perspective view illustrating the overall structure of a known ink-jet recording device  1 . FIG. 15 is a sectional view illustrating the overall structure of the known ink-jet recording device  1 . FIG. 16 is a perspective view schematically illustrating the positional relationship among a transport roller, a pinch roller, spurs, discharge rollers and so forth in the known ink-jet recording device  1 . FIG. 17 is a sectional view schematically illustrating the positional relationship among the spurs, discharge rollers and so forth in the known ink-jet recording device  1 . 
     As shown in FIG. 15, recording sheets P, as recording media, are stacked on a feeding section  2  and are fed sheet by sheet from the top of the stack by a feeding roller  22 . The recording sheet P fed by the feeding roller  22  is supported by a transport roller  36  and a pinch roller  37  while being sandwiched therebetween and is transported to the start point of recording on a platen  34  by the transport roller  36  which is driven by a drive source (not shown). 
     A recording head  7  is detachably mounted on a carriage  50 . The carriage  50  is movably mounted on a shaft  81  in a direction orthogonal to the transport direction of the recording sheet P. In other words, the recording head  7  performs recording while moving in a direction orthogonal to the transport direction of the recording sheet P. 
     A discharge roller shaft  41  is driven by a drive force of the transport roller  36  via a transmission roller  40 . As shown in FIG. 16, the discharge roller shaft  41  has a plurality of discharge rollers  41   a  made from elastomer or gum mounted thereon for transporting the recording sheet P. Spurs  42  press-contacting the corresponding discharge rollers  41   a  have a sharp-edged periphery in order to minimize an amount of ink of a recorded image transferred to the spurs  42 , since the spurs  42  come in contact with the recorded surface of the recording sheet P. 
     The recording sheet P is transported by the transport roller  36  and pinch roller  37  until the front end thereof is supported by the discharge rollers  41   a  and the spurs  42  while being sandwiched therebetween. After the rear end of the recording sheet P passes over the pinch roller  37 , the recording sheet P is transported by the discharge rollers  41   a  and the spurs  42 , and then is discharged and stored in a discharge tray  100 . 
     The platen  34  has a plurality of projected ribs  34   a  formed on the upper surface thereof along the transport direction of the recording sheet P and supports the plurality of spurs  42 , each disposed downstream of a corresponding projected rib  34   a . Since the projected ribs  34   a  on the platen  34  and the corresponding spurs  42  are arranged on the same lines parallel to the transport direction of the recording sheet P in order to suppress the raised height of any cockled recording sheet P, wherein the cockling of the recording sheet P can occur when ink is applied on the recording sheet P, cockling having a concave shape is formed at every portion of the recording sheet between the adjacent projected ribs  34   a , thereby minimizing the raised height of the cockled sheet lying in the recording area. 
     Such cockling is likely to occur especially when a permeable dye-type color ink is applied on the wide area of the recording sheet P. In the ink-jet recording device, the affect of the cockling must be eliminated and the gap between the recording sheet P and the recording head  7  must be maintained with the above arrangement in order to perform effective recording. 
     In recent years, a pigmentary black ink is used to increase black image density in the ink-jet recording device. The pigmentary ink requires a substantial time period for drying and fixing after the ink is applied on the recording sheet P. With this requirement, such pigmentary ink may cause a smear phenomenon in that a wet image formed on the previously discharged sheet is smeared by the currently discharging sheet because the front portion of the discharging sheet rubs the upper surface of the previously discharged sheet. 
     As shown in FIG. 15, a discharge section  4  of the recording device  1  has a discharge support  47  for preventing such smearing. The discharge support  47  supports the recording sheet that has been recorded, and extends the time period, from the applying time of ink on the recording sheet P to the arrival time of the recording sheet P at the discharge tray  100 , for drying the ink applied on the previously discharged sheet. 
     In the known recording device  1 , the platen  34  has the discharge support  47  that can be retracted therein. As shown in FIG. 15, the discharge support  47  usually retracts into the platen  34 , and is pulled out and protrudes from the platen  34  at the time of recording. A plurality of the discharge supports  47  is disposed between the adjacent spurs  42 . 
     While protruding from the platen  34 , all the discharge supports  47  guide the recording sheet P upward higher than the surface of the recording sheet P lying in the recording area and support the discharging sheet P so that it bends downwardly at its central portion under its own weight. The known recording device  1  provided with the discharge supports  47  extends the time period from the recording time to the arrival time of the recording sheet P at the discharge tray  100 . 
     However, in the known recording device  1  provided with the foregoing discharge supports  47 , some of the discharge supports  47  raise the cockling in the recording area, thereby causing the recording sheet P to form a convex shape instead of a concave shape of the cockling between the adjacent spurs  42 , and resulting in the substantially raised portions of the recording sheet P in the recording area. This causes the surface of the recording sheet P to come in contact with the recording head  7  or the carriage  50 , giving rise to problems such that the surface of the recording sheet gets dirty or the recording head  7  is damaged. 
     SUMMARY OF THE INVENTION 
     The present invention can provide a recording device, provided with a discharge support, in which the parts of the device are easily fabricated, a large space for the discharge support is not needed, and a required flatness of the upper surface of the platen is easily obtained. 
     The present invention can also provide a recording device that comprises (a) a recording head for performing recording on a recording medium, (b) a support for supporting the recording medium downstream from the recording head in the transport direction of the recording medium, (c) a guide for supporting the support and (d) a holder for holding the guide. The guide protrudes from and retracts toward the holder substantially in the transport direction of the recording medium, and the support protrudes from and retracts toward the guide in a direction different from the protruding direction of the guide. 
     Further objects, features and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view illustrating the overall structure of a recording device according to a first embodiment of the present invention. 
     FIG. 2 is a sectional view illustrating the overall structure of the recording device according to the first embodiment of the present invention. 
     FIG. 3 is another perspective view illustrating the overall structure of the recording device according to the first embodiment of the present invention. 
     FIG. 4 is a perspective view schematically illustrating the positional relationship among a transport roller, a pinch roller, spurs, discharge rollers and so forth of the recording device according to the first embodiment of the present invention. 
     FIG. 5 is a sectional view schematically illustrating the positional relationship among the spurs, the discharge rollers and so forth of the recording device according to the first embodiment of the present invention. 
     FIG. 6 is a perspective view illustrating a discharge section of the recording device viewed from the bottom thereof according to the first embodiment of the present invention. 
     FIG. 7 is a partially enlarged view of FIG.  6 . 
     FIG. 8 is a partially enlarged view illustrating a driving section for driving discharge supports of the recording device according to the first embodiment of the present invention. 
     FIG. 9 is an illustration of a state in which one of the discharge supports protrudes from a platen and supports a recording sheet. 
     FIG. 10 is an illustration of another state in which a recording sheet support portion as a downstream part of the discharge support lies at the lowest position and a guide protrudes from or retracts toward the platen. 
     FIG. 11 is an illustration of yet another state in which the guide has retracted toward the platen. 
     FIG. 12 is a sectional view illustrating the overall structure of a recording device according to a second embodiment of the present invention. 
     FIG. 13 is a sectional view illustrating the overall structure of a recording device according to a third embodiment of the present invention. 
     FIG. 14 is a perspective view illustrating the overall structure of a known ink-jet recording device. 
     FIG. 15 is a sectional view illustrating the overall structure of the known ink-jet recording device. 
     FIG. 16 is a perspective view schematically illustrating the positional relationship among a transport roller, a pinch roller, spurs, discharge rollers and so forth in the known ink-jet recording device. 
     FIG. 17 is a sectional view schematically illustrating the positional relationship among the spurs, discharge rollers and so forth in the known ink-jet recording device. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the accompanying drawings, preferred embodiments of the present invention will be described. 
     First Embodiment 
     Referring to FIGS. 1 and 2, a recording device  101  according to a first embodiment of the present invention will be described. All the same parts are identified by the same reference numerals throughout the drawings. 
     As shown in FIGS. 1 and 2, the recording device  101  has a feeding section  2 , a transport section  3 , a discharge section  4 , a carriage section  5 , and a cleaning section  6 . Referring to FIGS. 1 and 2, first the feeding section  2 , the transport section  3 , the carriage section  5 , and the cleaning section  6  will be described in that order, and then the discharge section  4 , which characterizes the recording device  101  of the first embodiment, will be described in detail. 
     (1) Feeding Section 
     The feeding section  2  has a base  20 , a pressure plate  21  for stacking recording sheets P, and a feeding roller  22  for feeding each recording sheet P, the latter two being attached to the base  20 . The pressure plate  21  has a movable side guide  23  mounted thereon for adjusting the stacking position of the recording sheets P. The pressure plate  21  is connected to the base  20  rotatably about a shaft  38  and is urged to the feeding roller  22  via a pressure spring  24 . The pressure plate  21  has a separation pad  25  mounted on a portion thereof that opposes the feeding roller  22 , wherein the pad  25  is made from a material such as artificial leather having a large frictional coefficient for preventing double feeding of the recording sheets P. 
     In addition, the base  20  has a separation claw  26  for individually separating the recording sheets P, a mound  27  integrally formed therewith for separating media such as a pasteboard and the like, which are not readily separated by the separation claw  26 , a switching lever  28  for allowing the separation claw  26  to work at a normal paper position and for preventing it from working at a pasteboard position, and a release cam  29  for releasing the abutment between the pressure plate  21  and the feeding roller  22 . 
     When the recording device  101  is in a stand-by mode, the release cam  29  pushes the pressure plate  21  down to a predetermined position so that the abutment between the pressure plate  21  and the feeding roller  22  is released. When a drive force of a transport roller  36  is transmitted to the feeding roller  22  and the release cam  29  by a gear and the like in this mode, the release cam  29  detaches from the pressure plate  21 , allowing the pressure plate  21  to be elevated, thereby allowing the feeding roller  22  to abut against the recording sheet P. Then, rotation of the feeding roller  22  causes the recording sheet P to be picked up, and the feeding operation of the recording sheet P starts. 
     The fed recording sheets P are separated individually by the separation claw  26  and are transported to the transport section  3 . The feeding roller  22  and the release cam  29  rotate so as to complete transportation of the recording sheet P to the transport section  3 , and the recording device  101  returns to the stand-by mode in which the abutment between the recording sheet P and the feeding roller  22  is released and the drive force of the transport roller  36  is removed. 
     (2) Transport Section 
     The transport section  3  has the transport roller  36  for transporting the recording sheet P and a paper end sensor (hereinafter, abbreviated as a PE sensor)  32 . The transport roller  36  has an idle pinch roller  37  which abuts thereagainst and which is rotatably held by a pinch roller guide  30 . The pinch roller guide  30  is urged by a pinch roller spring  31  so as to press-contact the pinch roller  37  to the transport roller  36 , thus producing a transport force for transporting the recording sheet P. 
     The transport section  3  has an upper guide  33  for guiding the recording sheet P and a platen  34  disposed at the entrance thereof to which the recording sheet P is transported. The upper guide  33  has a PE sensor lever  35  thereon for informing the PE sensor  32  of a detection of a front end and a rear end of the recording sheet P. 
     With the foregoing configuration, the recording sheet P transported to the transport section  3  is conveyed to a pair of rollers consisting of the transport roller  36  and the pinch roller  37 , while being supported by the platen  34  and being guided by the pinch roller guide  30 , and the upper guide  33 . In this stage, the PE sensor  32  detects the front end of the transported-recording sheet P on the basis of information from the PE sensor lever  35 . The recording device  101  determines the location of a recording area of the detected-recording sheet P with respect to the detected front end. 
     The recording sheet P is transported onto the platen  34  by rotation of the pair of rollers  36  and  37  driven by a line feed motor (hereinafter, abbreviated as an LF motor) (not shown). A recording head  7  has an ink tank detachably mounted thereon and can apply heat to ink supplied from the ink tank using a heater and the like as an electricity-energy converter. The heat causes film-boiling of the ink in the recording head  7 , and the film-boiling causes a bubble to grow or shrink. As a result of a pressure change generated by the growth or shrinkage of the bubble, an ink drop is discharged from a nozzle of the recording head  7 , thereby forming an image on the recording sheet P. 
     (3) Carriage Section 
     The carriage section  5  has a carriage  50  on which the recording head  7  is mounted. The carriage  50  is supported by a guide shaft  81  for allowing the recording head  7  to scan back and forth in a direction orthogonal to the transport direction of the recording sheet P, and a guide rail  82  for maintaining the clearance between the recording head  7  and the recording sheet P by holding the rear end of the carriage  50 . The guide shaft  81  and the guide rail  82  are mounted on a chassis  8 . 
     The carriage  50  is driven by a carriage motor  80  mounted on the chassis  8  via a timing belt  83 . The timing belt  83  is stretched and supported by an idle pulley  84 . The carriage  50  has a flexible circuit board (not shown) mounted thereon for transmitting a recording signal from an electrical circuit board (not shown) in the recording device  101  to the recording head  7 . Attachment and detachment of the recording head  7  to and from the carriage  50  and of the ink tank to and from the recording head  7  are performed at a given position to which the carriage  50  moves when an operation key (not shown) is pressed. 
     With this configuration, when an image is to be formed on the recording sheet P, the pair of rollers  36  and  37  transports the recording sheet P to a line position where the image is to be formed (a position on a line in the transport direction of the recording sheet P), and the carriage motor  80  drives the carriage  50  to move to a row position where the image is to be formed (a position on another line orthogonal to the transport direction of the recording sheet P) such that the recording head  7  faces a position where the image is to be formed. Then, the recording head  7  discharges ink drops toward the recording sheet P in response to a recording signal received from the electrical circuit board and thereby forms the image. 
     (4) Cleaning Section 
     The cleaning section  6  has a pump  60  for cleaning the recording head  7 , a cap  61  for preventing the recording head  7  from drying, and a drive switching arm  62  for switching a drive force of the transport roller  36  to either one of the feeding section  2  and the pump  60 . 
     Since the drive switching arm  62  has a planetary gear (not shown) which rotates about the axial center of the transport roller  36  that is fixed at a predetermined position thereof, the drive force of the transport roller  36  is not transmitted to the feeding section  2  and the pump  60  when operations other than feeding and cleaning are performed in the recording device  101 . 
     When the drive switching arm  62  is moved in the direction of arrow A indicated in FIG. 1 by movement of the carriage  50 , the planetary gear becomes free and moves in response to the normal rotation or reverse rotation of the transport roller  36 . That is to say, the drive force is transmitted to the feeding section  2  or the pump  60  when the transport roller  36  rotates normally or reversely, respectively. 
     (5) Discharge Section 
     The discharge section  4  has first and second discharge rollers  41   a  and  41 - 1   a , a first transmission roller  40  abutting against the first discharge rollers  41   a , and a second transmission roller  40 - 1  abutting against the second discharge rollers  41 - 1   a . The drive force of the transport roller  36  is transmitted to the first discharge rollers  41   a  via the first transmission roller  40  and is then transmitted to the second discharge rollers  41 - 1   a  via the second transmission roller  40 - 1 . The first discharge rollers  41   a  have first spurs  42  abutting thereagainst and the second discharge rollers  41 - 1   a  have second spurs  42 - 1  abutting thereagainst, each arranged for rotation driven by the first discharge rollers  41   a  and the second discharge rollers  41 - 1   a , respectively. The first and second spurs  42  and  42 - 1  have a cleaning roller  44  rotatably abutted thereagainst. 
     With the foregoing configuration, the recording sheet P, having the image formed thereon at the carriage section  5 , is transported while being interposed between a pair of the discharge rollers  41   a  and  41 - 1   a  and another pair of the spurs  42  and  42 - 1 , and then is discharged to a discharge tray  100 . 
     In addition, the second discharge rollers  41 - 1   a  have discharge supports  104 , for supporting the discharged recording sheet P, disposed downstream therefrom. The discharge supports  104  are rotatably attached to a guide  102 . The guide  102  protrudes from and retracts toward the platen  34 . The discharge supports  104  rotate in accordance with the linear motion of the guide  102 . The recording device  101  according to the first embodiment has five discharge supports  104  arranged in the width direction of the recording sheet P. 
     Referring now to FIGS. 3 to  11 , the structure and operations of the discharge section  4  of the recording device  101  according to the first embodiment will be described. FIG. 3 is a perspective view illustrating the overall structure of the recording device  101 . FIG. 4 is a perspective view schematically illustrating the positional relationship among the transport roller  36 , the pinch roller  37 , the spurs  42 , the discharge rollers  41   a  and so forth of the recording device  101 . FIG. 5 is a sectional view schematically illustrating the positional relationship among the spurs  42 , the discharge rollers  41   a  and so forth of the recording device  101 . FIG. 6 is a perspective view illustrating the discharge section  4  of the recording device  101  viewed from the bottom thereof. FIG. 7 is a partially enlarged view of FIG.  6 . FIG. 8 is a partially enlarged view illustrating a driving section for driving the discharge supports  104  of the recording device  101 . FIGS. 9 to  11  are sectional views of the discharge section  4  illustrating operations of the discharge section  4  of the recording device  101 . 
     As shown in FIG. 3, the platen  34  has a plurality of projected ribs  34   a  formed on the upper surface thereof extending along the transport direction of the recording sheet P and having a predetermined pitch in the width direction of the recording sheet P. The platen  34  has the first and second discharge rollers  41   a  and  41 - 1   a  downstream thereof arranged along the transport direction of the recording sheet P and in the width direction of the recording sheet P, each roller  41   a  and each roller  41 - 1   a  being aligned on the same line of the corresponding projected rib  34   a . The second discharge rollers  41 - 1   a  have the corresponding discharge supports  104  downstream therefrom. 
     With the foregoing configuration, in a recording area, the recording sheet P is properly positioned away from the recording head  7  by the transport roller  36  and the pinch roller  37  and also by the first discharge rollers  41   a  and the first spurs  42 . Thus, a combination of the first discharge rollers  41   a  and the first spurs  42  and another combination of the second discharge rollers  41 - 1   a  and the second spurs  42 - 1  support the recording sheet P by sandwiching it therebetween and then discharge it. 
     In the recording device  101 , aligning each of the projected ribs  34   a  on the platen  34 , the corresponding first spur  42 , second spur  42 - 1 , and discharge support  104  substantially on the same line along the transport direction of the recording sheet P and aligning like components in the width direction of the recording sheet P allows the recording sheet P to form concave cockling at the time of recording between the adjacent projected ribs  34   a . FIG. 5 illustrates a state in which the concave cockling occurs at the time of recording between the adjacent projected ribs  34   a  on the platen  34 . 
     Next, the structure of the discharge supports  104  of the recording device  101  according to the first is embodiment will be described. The discharge supports  104  are supported by the guide  102  and a guide  103  and protrude from and retract toward the platen  34 . Once the discharge supports  104  have protruded from the platen  34 , the discharge supports  104  guide and support the recording sheet P upward from the horizontal surface on which a part of the recording sheet P lying in the recording area is supported. 
     The recording sheet P of A-4 size is supported by the discharge supports  104 - 1  to  104 - 3  and the recording sheet P of A-3 size is supported by all the discharge supports  104 - 1  to  104 - 5 . The discharge supports  104  support the recording sheet P so that the central portion of the recording sheet P warps downward under its own weight. In the recording device  101 , the discharge supports  104 - 1  and  104 - 5  have the same shape, and the discharge supports  104 - 2  and  104 - 4  have the other same shape, taking the A-3 size width as a basic structure. 
     In a state in which the discharge supports  104  protrude from the platen  34 , the downstream highest portions, i.e., the recording sheet support portions, of the discharge supports  104 - 1  and  104 - 5  are higher than those of the discharge supports  104 - 2  and  104 - 4 . Also, the recording sheet P of A-4 size is supported by the discharge supports  104 - 1  to  104 - 3  as described above, and the downstream highest portion of the discharge support  104 - 3  is slightly higher than that of the discharge support  104 - 2 . 
     In the recording device  101 , when moderate density recording is performed on the recording sheet P of A-3 size, the recording sheet P is supported by the discharge supports  104 - 1 ,  104 - 3 , and  104 - 5 . When high print density recording is performed on the above recording sheet P, the recording sheet P is also supported by the discharge supports  104 - 2  and  104 - 4  so as to prevent it from becoming buckled and thereby jackknifed between the discharge supports  104 - 1  and  104 - 5 . In this embodiment, the downstream highest portion of the discharge support  104 - 3  is set to be higher than those of the discharge supports  104 - 2  and  104 - 4 ; however, it may be as high as or lower than those of the discharge supports  104 - 2  and  104 - 4 . 
     As shown in FIG. 9, the discharge supports  104 - 1  and  104 - 2  are supported by the guide  102  in a rotatable manner about a shaft  102   c  of the guide  102 . Likewise, the discharge supports  104 - 3  to  104 - 5  are supported by the guide  103  in a rotatable manner about a shaft (not shown) of the guide  103 . 
     The recording sheet support portions  104   b  of the discharge supports  104  have a gradual upward-canted shape toward their downstream ends. After the front end of the recording sheet P that has been recorded abuts against the recording sheet support portions  104   b , the recording sheet P is supported by the recording sheet support portions  104   b  and thus is transported smoothly. Also, each of the discharge supports  104  has a cam crest  104   a  at its upstream end for determining a vertical position of the recording sheet support portion  104   b  at its downstream end by abutting against cam rails  341  to  344  of the platen  34  that will be described later. Furthermore, each of the discharge supports  104  has a boss  104   c  at the underside of its upstream end. As shown in FIGS. 10 and 11, each of the discharge supports  104  and the guide  102  have a spring  114  inserted therebetween so that the cam crest  104   a  abuts against the cam rails  341  to  344  all the time. 
     As shown in FIG. 8, the guide  103  has guide rails  103   c  on both sides thereof abutting against guide grooves  34   c  disposed on the platen  34 . The guide  103  protrudes from and retracts toward the platen  34  by its guide rails  103   c  slideably and linearly moving along the guide grooves  34   c  of the platen  34 . Likewise, the guide  102  protrudes from and retracts toward the platen  34  by slideably and linearly moving along guide rail  102   b  and the guide grove  34   c  of the platen  34  (FIG.  6 ). As shown in FIGS. 6 and 7, the guide  103  has two projected guide rails  103   c  thereon, engaging with the respective guide grooves  34   c  of the platen  34 . 
     Also, the guide  102  has a rack  102   a  at the bottom thereof and the guide  103  has two racks  103   a  and  103   b  at the bottom thereof. The platen  34  has a drive shaft  109  rotatably supported by a bearing  34   b  disposed on the platen  34 . Engaging pinion gears  109   a ,  109   b , and  109   c  provided on the drive shaft  109  with the racks  102   a ,  103   a , and  103   b , respectively, of the guides  102  and  103  allows the guides  102  and  103  to move. 
     With the foregoing configuration, the guides  102  and  103  move linearly so as to protrude from and retract toward the platen  34  by a rotation of the drive shaft  109 . The guides  102  and  103  are positioned in desired positions (not shown) when protruding from the platen  34 . 
     The drive shaft  109  has a gear  109   d  disposed at one end thereof. Transmission gears  110  and  111  are rotatably supported by a bearing  34   d  (FIG. 7) disposed on the platen  34 . The transmission gear  111  is coaxially arranged with the transmission gear  110  and engages with a motor gear  113  of a motor  112 . The transmission gears  110  and  111  have a torque limiter (not shown) therebetween urged by a spring (not shown). This arrangement avoids cog slip between the pinion gears  109   a ,  109   b , and  109   c  and the respectively corresponding racks  102   a ,  103   a , and  103   b , when the guides  102  and  103  are driven by the motor  112  and then stop upon bumping into predetermined points of the platen  34 . 
     Operations of the discharge supports  104  will now be described. In the recording device  101 , the discharge supports  104  are controlled so as to extrude prior to the start of recording by the recording head and retract upon a discharging operation of the recording sheet P after completion of recording. 
     In the recording device  101  according to the first embodiment, the motor  112  drives the motor gear  113  for rotation, allowing the drive force thereof to be transmitted to the transmission gear  111  and then to the drive shaft  109  via the transmission gear  110  and the gear  109   d  for rotation of the drive shaft  109 . The guides  102  and  103  move linearly by engagement of the pinion gears  109   a  to  109   c  provided on the drive shaft  109  with the corresponding racks  102   a ,  103   a , and  103   b , respectively. The discharge supports  104  protrude from and retract toward the guides  102  and  103  in response to the movements of the guides  102  and  103 . 
     FIG. 9 illustrates a state in which the discharge support  104  protrudes from the platen  34  and supports the recording sheet P. FIG. 10 illustrates a state in which the recording sheet support portion  104   b  at the downstream end of the discharge support  104  lies at its lowest point and the guide  102  is protruding from or retracting toward or into the platen  34 . FIG. 11 illustrates a state in which the guide  102  has retracted into the platen  34 . 
     As shown in FIG. 11, when the guide  102  retracts toward the platen  34 , the discharge support  104  has retracted to the guide  102 . In this stage, the cam crest  104   a  has abutted against the cam rail  344  of the platen  34  urged by the spring  114 . 
     As shown in FIG. 10, rotation of the pinion gear  109   a  of the drive shaft  109  allows the rack  102   a  engaging with the pinion gear  109   a  to move and thereby the guide  102  to start protruding. The cam crest  104   a  of the discharge support  104  slides along the cam rails  344  and  343  of the platen  34  against the force of the spring  114 . 
     When the recording sheet support portion  104   b  of the discharge support  104  passes the second discharge roller  41 - 1   a  and the cam crest  104   a  abuts against a sloped cam rail  342 , the cam crest  104   a  is lowered and the recording sheet support portion  104   b  of the discharge support  104  is gradually raised. Then, as shown in FIG. 9, the recording sheet support portion  104   b  reaches its highest position while the cam crest  104   a  abuts against the lowest surface of the cam rail  341 . The guide  102  bumps into a predetermined point of the platen  34  and stops, allowing the recording sheet support portion  104   b  of the discharge supports  104  to be held at a predetermined point. After the front end of the recording sheet P passes the second spur  42 - 1 , the recording sheet P abuts against the slope of the discharge support  104 , is transported along the slope, and is supported by the downstream lowest point of the discharge support  104 . 
     Timing for protrusion and retraction of the discharge supports  104  and the guides  102  and  103  is controlled by control means (not shown) on the basis of sizes of the recording sheets P, timing for recording in the recording area, and so forth. 
     Although the recording device  101  according to the first embodiment initiates protrusion of the discharge supports  104  before the recording head  7  starts recording, the recording device  101  may initiate protrusion of the discharge supports  104  during recording as long as the protrusion does not affect the recorded image. 
     When a thick special sheet such as a pasteboard, on which high quality recording is required and which has little potential for cockling, is used as a recording medium, high stiffness of the sheet itself has a negative effect on the angle of the sheet around the recording area thereof because of the slope of the discharge supports  104 . Therefore, in this case, the recording device  101  may control recording and discharging of the recording sheet P without the discharge supports  104  protruding from the platen  34 . 
     Also, though the recording device  101  according to the first embodiment has the guides  102  and  103  facing the recording head  7  so as to protrude from and retract toward the platen  34  for supporting the recording sheet P, the recording device  101  may be provided with a special holder (not shown) downstream thereof, in addition to the platen  34 , for holding the guides  102  and  103 , and may be configured such that the guides  102  and  103  protrude from and retract toward the holder. 
     According to the first embodiment, since each of the projected ribs  34   a  on the platen  34 , the corresponding first spur  42  and first discharge roller  41   a  are aligned on the same line along the transport direction of the recording sheet P and like components are aligned in the width direction of the recording sheet P, the shape of any generated cockling is not affected by the discharge supports  104 . Also, the guides are provided so as to protrude from and retract toward the platen, and the discharge supports are provided so as to protrude from and retract toward the guides, thereby providing discharge supports without employing a complicated mechanism. 
     Second Embodiment 
     A recording device according to a second embodiment of the present invention will be described. FIG. 12 is a sectional view illustrating the configuration of a recording device  1101  according to the second embodiment. As shown in FIG. 12, the discharge roller and the spur are disposed in a row, making the device of the second embodiment different from that of the first embodiment. 
     In the recording device  1101 , a drive force of the transport roller  36  is transmitted to the discharge roller  41   a  via the transmission roller  40  at the discharge section  4 . The discharge support  104  is disposed on the same line with the spur  42  along the transport direction of the recording sheet P and two or more discharge supports are disposed across the width direction of the recording sheet P. Operations of the recording device  1101  are the same as those of the recording device  101 . 
     According to the second embodiment, the recording device  1101  having a set of the discharge roller  41   a  and the spur  42  which are disposed in a row requires a further smaller space for the discharge support  104  than that of the recording device  101  according to the first embodiment. 
     Third Embodiment 
     A recording device according to a third embodiment of the present invention will be described. FIG. 13 is a sectional view illustrating the configuration of a recording device  2101  according to the third embodiment. As shown in FIG. 13, the recording device  2101  has a roller  120  rotatably mounted at a downstream portion of the discharge support  104 . Supporting the recording sheet P by the roller  120  leads to reduction in the friction caused by transporting the recording sheet P. Operations of the recording device  2101  are the same as those of the recording device  101 . 
     According to the third embodiment, the recording device  2101  having a roller  120  at a downstream portion of the discharge support  104  accurately transports the recording sheet P, thereby providing a high-quality recorded image. 
     The foregoing discharge support mechanism is applicable to a recording device provided with a recording head employing an electrothermal converter or a piezo-electric element. One skilled in the art will appreciate that the discharge mechanism is also applicable to a recording device provided with a recording head other than an ink-jet type. 
     In the recording device according to the third embodiment, the guide protrudes from and retracts toward the platen and the discharge support protrudes from and retracts toward the guide, providing the discharge support without employing a complicated mechanism. This configuration allows the discharge support to move in a smaller working area when the discharge support is aligned substantially on the same line with the discharge roller or the spur along the transport direction of the recording sheet, with two or more discharge supports disposed across the width direction of the recording sheet. 
     The smaller working area of the discharge support increases the strength of the platen, making it easy to achieve a required flatness of each rib formed on the upper surface of the platen, thereby leading to maintaining a certain amount of gap between the recording head and the recording sheet P. 
     While the present invention has been described with reference to what are presently considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.