Patent Publication Number: US-2016229201-A1

Title: Recording Apparatus

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to a recording apparatus including a medium supporting unit that supports a medium. 
     2. Related Art 
     To date, there is a known ink jet printer that includes a pair of rollers for feeding vinyl chloride film, a liquid ejection unit that performs recording by ejecting solvent ink onto the film, and a downstream-side supporting unit that is arranged on the film feed downstream side of the pair of rollers and that supports the film. This downstream-side supporting unit curves (bends) in such a manner that the height thereof decreases toward the film feed downstream side (JP-A-2013-154612). 
     The inventors have found the following problems. 
     In a recording apparatus such as a conventional ink jet printer, in the case where a medium supporting unit is curved, it is easy for the medium to come into close contact with the medium supporting unit. Consequently, there is a risk of the medium sticking to the medium supporting unit by static electricity. Further, in the case where the medium supporting unit is bent, wrinkles may form in the medium being fed to the medium supporting unit due to the accumulation and swelling of ink, and there is a risk of creases being formed in the medium along the feed direction of the medium by these wrinkles being drawn and growing at the angular portion of bent portions. 
     SUMMARY 
     An advantage of some aspects of the invention is that a recording apparatus is provided which can suppress sticking of a medium to a medium supporting unit and suppress the formation of creases in the medium on the medium supporting unit. 
     A recording apparatus according to an aspect of the invention includes a feeding unit that feeds a medium, a recording section that performs recording by applying ink to the medium, and a medium supporting unit that is arranged on a medium feed downstream side of the feeding unit and that supports the medium, in which the medium supporting unit includes a bent portion that is bent so that a side that comes into contact with the medium is convex and that extends in a direction that crosses the feed direction of the medium, and a bend angle of the bent portion is equal to or more than 3° and equal to or less than 16° 
     According to this configuration, because the medium supporting unit includes the bent portion, it becomes difficult for the medium to be in close contact with the medium supporting unit. Consequently, sticking of the medium to the medium supporting unit by static electricity is suppressed. Further, because the bend angle of the bent portion is small, that is, equal to or more than 3° and equal to or less than 16°, drawing of wrinkles that have formed in the medium at the angular portion of the bent portion is suppressed. Consequently, it is difficult for creases to form in the medium along the feed direction of the medium. That is, the recording apparatus is capable of suppressing sticking of the medium to the medium supporting unit and suppressing the formation of creases in the medium on the medium supporting unit. 
     In this case, it is preferable that the medium supporting unit include a plurality of bent portions. 
     According to this configuration, it becomes difficult for the medium to be in close contact with the medium supporting unit. Consequently, the sticking of the medium to the medium supporting unit by static electricity is suppressed more effectively. 
     In this case, it is preferable that the plurality of bent portions be arranged side by side in the feed direction of the medium and the space between adjacent ones of the bent portions become increasingly wide towards the medium feed downstream side. 
     In this case, it is preferable that a heating unit that heats the medium through the medium supporting unit be further provided. 
     According to this configuration, when the medium passes over the medium supporting unit, drying of the medium is promoted. 
     In this case, it is preferable that the recording section apply, as the ink, sublimation ink to the medium. 
     In this case, it is preferable that a take-up section that is arranged on the medium feed downstream side of the medium supporting unit and that takes up the medium be further provided. 
     If creases form in the medium along the feed direction of the medium, it becomes easy for winding deviation to occur in a roll into which the medium has been wound up by the take-up section. 
     In contrast, according to this configuration, as described above, because it is difficult for creases to form in the medium, it is possible to suppress the occurrence of winding deviation in a roll into which the medium has been wound up by the take-up section. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a structural diagram of the recording apparatus according to an embodiment of the invention. 
         FIG. 2  is a block diagram depicting control of the recording apparatus illustrated in  FIG. 1 . 
         FIG. 3A  is a diagram illustrating a perspective view of a medium supporting unit included in the recording apparatus illustrated in  FIG. 1 . 
         FIG. 3B  is a diagram illustrating a cross-sectional view of a medium supporting unit included in the recording apparatus illustrated in  FIG. 1 . 
         FIG. 4A  is a diagram illustrating a perspective view of the medium supporting unit included in the recording apparatus of Comparative Example 1. 
         FIG. 4B  is a diagram illustrating a cross-sectional view of the medium supporting unit included in the recording apparatus of Comparative Example 1. 
         FIG. 5A  is a diagram illustrating a perspective view of the medium supporting unit included in the recording apparatus of Comparative Example 2. 
         FIG. 5B  is a diagram illustrating a cross-sectional view of the medium supporting unit included in the recording apparatus of Comparative Example 2. 
         FIG. 6A  is a photograph depicting a state in which creases are not formed in transfer paper on the medium supporting unit included in the recording apparatus illustrated in  FIG. 1 . 
         FIG. 6B  is a photograph depicting a state in which creases have been formed in the transfer paper on the medium supporting unit included in the recording apparatus of Comparative Example 2. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Below, a recording apparatus  1  according to an embodiment of the invention will be described with reference to the attached drawings. The recording apparatus  1  forms an image on transfer paper  100  by applying sublimation ink thereon by using an ink jet method. The transfer paper  100  on which the image has been formed is then supplied to a heat transfer printing device and is heated while being stacked on a dye target object such as a cloth so that the image formed on the transfer paper  100  is transferred to the dye target object. 
     The basic configuration of the recording apparatus  1  will be described with reference to  FIG. 1 . The recording apparatus  1  includes a medium feeding system  2 , a platen  3 , a recording section  5 , a drying section  6 , and a supporting frame  7  that supports the aforementioned. Further, although not illustrated in  FIG. 1 , the recording apparatus  1  includes a control unit  9  (refer to  FIG. 2 ). 
     The medium feeding system  2  feeds out the transfer paper  100 , which is a continuous paper sheet, using a roll-to-roll method. The medium feeding system  2  includes a delivery section  11 , a feeding unit  12 , and a take-up section  13 . 
     A delivery-side roll  101 , which is the transfer paper  100  wound up into a roll, is set in the delivery section  11 . The delivery section  11  includes a delivery-side supporting unit  14  and a delivery motor  15  (refer to  FIG. 2 ). The delivery-side supporting unit  14  rotatably supports the delivery-side roll  101 . The delivery motor  15  is a drive source that rotates the delivery-side roll  101 . When the delivery motor  15  operates, the delivery-side roll  101  rotates in a delivery direction and the transfer paper  100  is reeled out from the delivery-side roll  101 . 
     The feeding unit  12  feeds the transfer paper  100  reeled out from the delivery-side roll  101  toward the take-up section  13 . The feeding unit  12  includes a roller pair  16  and a feed motor  17  (refer to  FIG. 2 ). Moreover, the number of roller pairs  16  is not particularly limited, and a plurality of roller pairs  16  may be laid out along the feed path of the transfer paper  100 . The roller pair  16  includes a driving roller  18  and a driven roller  19 . The driving roller  18  rotates by power being transmitted from the feed motor  17 . The driven roller  19  is rotated along with the rotation of the driving roller  18 . The transfer paper  100  is pinched between the driving roller  18  and the driven roller  19 . The feed motor  17  is a drive source that rotates the driving roller  18 . When the feed motor  17  operates, the driving roller  18  rotates and the driven roller  19 , which is pressed against the driving roller  18 , is rotated along with the rotation of the driving roller  18 . Consequently, the transfer paper  100  that is pinched between the driving roller  18  and the driven roller  19  is fed toward the take-up section  13 . 
     Further, the driving roller  18  is provided with a feed-side detection unit  21  (refer to  FIG. 2 ) that includes a rotary encoder. On the basis of a pulse output from the feed-side detection unit  21 , the rotation angle α 1  of the driving roller  18  is detected. 
     The take-up section  13  winds up into a roll the transfer paper  100  that has been fed thereto. According to this embodiment, the take-up section  13  winds up the transfer paper  100  in such a manner that a recording surface  100   a  on which sublimation ink has been applied by the recording section  5  is on the outside and a non-recording surface  100   b  on which sublimation ink has not been applied is on the inside. Further, the transfer paper  100  may be wound in such a manner that the recording surface  100   a  on which sublimation ink has been applied by the recording section  5  is on the inside and the non-recording surface  100   b  on which sublimation ink has not been applied is on the outside. The take-up section  13  includes a take-up-side supporting unit  22  and a take-up motor  23  (refer to  FIG. 2 ). The take-up-side supporting unit  22  rotatably supports a paper tube  24  that can perform winding. The leading end of the transfer paper  100  is attached to the paper tube  24 . The paper tube  24  rotates by power being transmitted from the take-up motor  23  via a gear train. The take-up motor  23  is a drive source that rotates the paper tube  24 . When the take-up motor  23  rotates in one direction, the paper tube  24  rotates in the take-up direction and the transfer paper  100  is wound around the paper tube  24 . The roll formed by winding the transfer paper  100  around the paper tube  24  is called a take-up-side roll  102 . When the take-up motor  23  rotates in the other direction, the paper tube  24  rotates in a rotation direction opposite to the take-up direction, and the transfer paper  100  wound around the paper tube  24  is unwound. 
     Further, the take-up motor  23  is provided with a take-up-side detection unit  25  including a rotary encoder (refer to  FIG. 2 ). On the basis of a pulse output from the take-up-side detection unit  25 , the rotation angle α 0  of the take-up motor  23  is detected. 
     The platen  3  is provided on the transfer paper  100  feed downstream side of the roller pair  16 . The platen  3  supports the transfer paper  100  that passes over the top surface of the platen  3 . A plurality of suction holes  26  are provided in the platen  3 . The suction holes  26  continue to a suction fan (not illustrated). When the suction fan operates, a negative pressure acts on the suction holes  26 , and the transfer paper  100  is sucked onto the top surface of the platen  3 . Consequently, detachment of the transfer paper  100  from the top surface of the platen  3  is suppressed, and the transfer paper  100  is prevented from interfering with a recording head  27  of the recording section  5  (described below). 
     The recording section  5  is provided opposite the top surface of the platen  3 . The recording section  5  includes a carriage  28  and the recording head  27  mounted on the carriage  28 . The recording head  27  ejects sublimation ink onto the transfer paper  100  that is sucked onto the top surface of the platen  3 . The carriage  28  having the recording head  27  mounted thereon is formed so as to be capable of reciprocating in a direction crossing the feed direction of the transfer paper  100 . 
     The drying section  6  is provided on the transfer paper  100  feed downstream side of the recording section  5 . The drying section  6  includes a medium supporting unit  31  and a heater wire  32  provided on the rear surface of the medium supporting unit  31 . Since the heater wire  32  generates heat, when the transfer paper  100  that has had sublimation ink applied thereon passes over the front surface of the medium supporting unit  31 , drying of the transfer paper  100  is promoted. The medium supporting unit  31  will be described below. 
     The supporting frame  7  includes a bar member  33 . The bar member  33  forms the feed path of the transfer paper  100  between the drying section  6  and the take-up section  13 . 
     The recording apparatus  1  formed in the above manner, repeatedly alternately performs an operation of ejecting sublimation ink from the recording head  27  while moving the carriage  28  during stoppage of intermittent feeding of the transfer paper  100  by the medium feeding system  2  and an operation of intermittently feeding the transfer paper  100  by the medium feeding system  2 . Consequently, an image to be transferred to a transfer target object is formed on the transfer paper  100 . 
     The control system of the recording apparatus  1  will be described with reference to  FIG. 2 . The control unit  9  includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like, which are not illustrated. The CPU of the control unit  9  loads a program from the ROM and runs the program using the RAM, and controls each unit of the recording apparatus  1 . Further, a host device (for example, a personal computer), which is not illustrated, is communicatively connected to the control unit  9 . The control unit  9  is provided with image data expressing the print image from the host device or the like. The control unit  9  controls the ejection operation of the recording head  27  on the basis of the image data. 
     The control unit  9  controls the take-up motor  23  on the basis of a set torque T. Consequently, the transfer paper  100  is taken up by the take-up section  13  while the transfer paper  100  is under constant tension. The control unit  9  calculates the set torque T by performing initialization control at the start of operation of the recording apparatus  1 . 
     Here, the method of calculating the set torque T will be described. The control unit  9 , when starting initialization control, first causes the feed motor  17  to rotate while the take-up motor  23  is stopped. Consequently, the transfer paper  100  becomes slack between the roller pair  16  and the take-up section  13 . The control unit  9  causes the take-up motor  23  to rotate while the transfer paper  100  is in a slack state. Consequently, the control unit  9  obtains an offset torque T 0  of the take-up motor  23 . The offset torque T 0  is obtained on the basis of the value of an electric current that is necessary for rotating the take-up motor  23  at a static load time. 
     Subsequently, the control unit  9  causes the feed motor  17  and the take-up motor  23  to rotate while the transfer paper  100  is under tension between the roller pair  16  and the take-up section  13 . The control unit  9  calculates from the following equation a set time feed rate L which is the feed rate of the transfer paper  100  that has been fed at this time on the basis of the relationship between the rotation angle α 1  of the driving roller  18  detected by the feed-side detection unit  21  and a roller radius r of the driving roller  18 , which is already known. 
     
       
      
       L=r·α 
       1  
      
     
     Then, the control unit  9  calculates from the following equation a roll radius R of the take-up-side roll  102  on the basis of the set time feed rate L, the rotation angle α 2  of the take-up motor  23  detected by the take-up-side detection unit  25 , and a speed reduction ratio N of a gear train between the take-up motor  23  and the paper tube  24 , which is already known. 
         R =( L/α   2 )· N  
 
     Further, the speed reduction ratio N is a value given by N=α 2 /α 0  when the rotational angle of the paper tube  24  is α 0 . 
     Subsequently, the control unit  9  sets a set tension F. The control unit  9 , for example, stores a table of the relationship between the type of the transfer paper  100  and the value of the tension, and by referring to that table, sets the set tension F. 
     The control unit  9  calculates from the following equation the set torque T of the take-up motor  23  on the basis of the offset torque T 0 , the roll radius R, and the set tension F obtained in this way. 
         T =( F·R−T   0 )/ N    
     The control unit  9 , in this way, controls the take-up motor  23  on the basis of the set torque T according to the roll radius R of the take-up-side roll  102 . Consequently, for example, when recording is performed by the recording section  5 , even in the case where the control unit  9  causes the take-up motor  23  and the feed motor  17  to operate at the same time, excessive winding up of the transfer paper  100  by the take-up section  13  as well as insufficient winding up of the transfer paper  100  by the take-up section  13  can be suppressed. 
     The medium supporting unit  31  will be explained with reference to  FIGS. 3A and 3B . The medium supporting unit  31  is made by bending an aluminum plate and includes seven bent portions  35 . Further, the number of bent portions  35  is not particularly limited. The bent portions  35  are bent in such a manner that the side that is in contact with the transfer paper  100  is convex. The surface that is in contact with the transfer paper  100  is a bent surface. Further, the bent portions  35  extend in a direction that crosses the feed direction of the transfer paper  100 . That is, the medium supporting unit  31  is formed of the bent portions  35  that are bent along a direction that crosses the feed direction of the transfer paper  100 . The seven bent portions  35  are arranged side by side in the feed direction of the transfer paper  100  and the space between adjacent ones of the bent portions  35  becomes increasingly wide towards the feed downstream side. 
     The bend angles of the bent portions  35  are in order starting from the bent portion  35  on the upstream side, θ 1 =15.63°, θ 2 =6.74°, θ 3 =3.81°, θ 4 =4.82°, θ 5 =12.97°, θ 6=4.58° , and θ 7 =13.45° (below, in the case where it is not necessary to distinguish between the bend angles θ 1  to θ 7 , these are generally referred to as “bend angle θ”). As described above, the bend angle θ of the bent portions  35  is equal to or more than 3° and equal to or less than 16°. 
     Here, depending on the shape of the medium supporting unit  31 , the transfer paper  100  may come into close contact with the medium supporting unit  31  and there is a risk that the transfer paper  100  might stick to the medium supporting unit  31  by static electricity. In particular, as described above, at the initialization control time of the recording apparatus  1 , because the transfer paper  100  is fed by the feeding unit  12  while the taking up of the transfer paper  100  by the take-up section  13  is stopped in order to make the transfer paper  100  be in a slack state between the roller pair  16  and the take-up section  13 , the transfer paper  100  easily sticks to the medium supporting unit  31  because the transfer paper  100  is not pulled by the take-up section  13 . 
     In contrast, according to the recording apparatus  1  of this embodiment, because the medium supporting unit  31  includes the bent portions  35 , it becomes difficult for the transfer paper  100  to be in close contact with the medium supporting unit  31 . Consequently, while the taking up of the transfer paper  100  by the take-up section  13  is stopped, even when the transfer paper  100  is fed by the feeding unit  12 , it is possible to suppress the sticking of the transfer paper  100  to the medium supporting unit  31  by static electricity. 
     However, if the bend angle θ of the bent portions  35  is large, wrinkles may form due to the accumulation and swelling of sublimation ink in the transfer paper  100  that is being fed to the medium supporting unit  31 , and there is a risk of creases being formed in the transfer paper  100  along the feed direction of the transfer paper  100  by these wrinkles being drawn and growing at the angular portions of the bent portions  35 . In particular, at the time of recording after the end of the initialization control of the recording apparatus  1 , as described above, the take-up section  13  operates at the same time as the feeding unit  12 , and because the transfer paper  100  is fed while under a set tension F, wrinkles formed in the transfer paper  100  are strongly drawn at the angular portions of the bent portions  35  and creases easily form in the transfer paper  100 . 
     If creases form in the transfer paper  100 , it becomes easy for a winding deviation to occur in which the end surface of the transfer paper  100  does not line up with the take-up-side roll  102 . The winding deviation of the take-up-side roll  102  causes, for example, the transfer paper  100  to meander in a heat transfer printing device. Moreover, if creases form in the transfer paper  100  and if the recording surface  100   a,  in which creases have been formed, and the non-recording surface  100   b  of the transfer paper  100  that has been wound up on the outer side of the take-up-side roll  102  come into contact, there is a risk of the sublimation ink applied to the recording surface  100   a  in which creases have been formed being transferred to the non-recording surface  100   b  of the transfer paper  100  wound up on the outer side of the take-up-side roll  102 . If such rear-side transfer occurs in the take-up-side roll  102 , the amount of sublimation ink applied to the recording surface  100   a  will decrease only in the part subjected to rear-side transfer, and because the amount of color material transferred to the transfer target object varies depending on the location of the recording surface  100   a,  a color irregularity occurs in the image transferred to the transfer target object by the heat transfer printing device. Furthermore, there is also a case where creases that occur in the medium supporting unit  31  progress to the feed upstream side of the transfer paper  100 , in such a case, there is a risk that the position at which the creases are formed projects out in the thickness direction of the transfer paper  100  and the transfer paper  100  may interfere with the recording head  27 . 
     In contrast, according to the recording apparatus  1  of this embodiment, because the bend angle  0  of the bent portions  35  is small, that is, equal to or more than 3° and equal to or less than 16°, drawing of wrinkles that have formed in the transfer paper  100  at the angular portions of the bent portions  35  is suppressed. Consequently, it is difficult for creases to form in the transfer paper  100  along the feed direction of the transfer paper  100 . As a result, the occurrence of winding deviation of the take-up-side roll  102 , the occurrence of rear-transfer on the take-up-side roll  102 , and interference between the creases and the recording head  27  can be suppressed. 
     Below, an example and comparative examples are given and the invention is explained more concretely. 
     The recording apparatus  1  of this embodiment is used as Example 1. 
     As Comparative Example 1, an apparatus substantially the same as the recording apparatus  1  of this embodiment is used except that a medium supporting unit  31 A which is illustrated in  FIGS. 4A and 4B  is included instead of the above described medium supporting unit  31 . The medium supporting unit  31 A does not include the bent portions  35  and the surface that is in contact with the transfer paper  100  is a curved surface. 
     As Comparative Example 2, an apparatus substantially the same as the recording apparatus  1  of this embodiment is used except that a medium supporting unit  31 B which is illustrated in  FIGS. 5A and 5B  is included instead of the above described medium supporting unit  31 . The position of the upstream end portion of the medium supporting unit  31 B and the position of the downstream end portion of the medium supporting unit  31 B are substantially the same as those of the medium supporting unit  31 , however, the number of bent portions  35  is three, which is smaller. Accordingly, the bend angles of the bent portions  35  are in order from the bent portion  35  on the feed upstream side, θ a =22.36°, θ b =23.33°, and θ c =16.31°, and are larger than the bend angles θ 1  to θ 7 . In other words, all of the bend angles θ a  to θ c  exceed 16°. 
     Further, “TexPrint (registered trademark) XPHR  44  inch width” paper (paper weight: 105 g/m 2 ) of the Beaver Paper and Graphic Media, Inc. was used as the transfer paper  100 . 
     In the example and comparative examples, when feeding the transfer paper  100  during initialization control, it was evaluated whether or not the transfer paper  100  stuck to the medium supporting unit  31 . 
     In Example 1, sticking of the transfer paper  100  was not observed. 
     In Comparative Example 1, sticking of the transfer paper  100  was observed. 
     In Comparative Example 2, sticking of the transfer paper  100  was not observed. 
     Regarding the example and comparative examples, by performing the operation of feeding the transfer paper  100  at the time of recording after the end of initialization control, it was evaluated whether or not creases formed in the transfer paper  100  on the medium supporting unit  31 . 
     In Example 1, the formation of creases in the transfer paper  100  was not observed (refer to  FIG. 6A ). 
     In Comparative Example 1, the formation of creases in the transfer paper  100  was not observed. 
     In Comparative Example 2, the formation of creases in the transfer paper  100  was observed (in  FIG. 6B , creases are observed in the portions surrounded by ellipses). 
     As stated above, according to the recording apparatus  1  of this embodiment, sticking of the transfer paper  100  to the medium supporting unit  31  is suppressed and it is possible to suppress the occurrence of creases in the transfer paper  100  on the medium supporting unit  31 . 
     Further, because the medium supporting unit  31  according to the recording apparatus  1  of this embodiment has a plurality of the bent portions  35 , it is difficult for the transfer paper  100  to be in close contact with the medium supporting unit  31 . Consequently, the sticking of the transfer paper  100  to the medium supporting unit  31  by static electricity is suppressed more effectively. 
     Further, the heater wire  32  is one example of the “heating unit”. The transfer paper  100  is one example of the “medium”. 
     The invention is not limited to the above described embodiment, and it goes without saying that it is possible to adopt various configurations as long as they do not deviate from the scope of the invention. For example, the embodiment can be changed to the following form. 
     The ink ejected by the recording section  5  is not limited to sublimation ink and may be, for example, water-based ink, oil-based ink, solvent ink, or ultraviolet curable type ink. Further, the material of the medium is not particularly limited, and items made of various materials such as paper-type or film-type items may be used. Further, an inexpensive thin item (for example, paper weight of 75 g/m 2  or less) is often used for the transfer paper  100 . In that case, the transfer paper  100  easily sticks to the medium supporting unit  31  by static electricity or the like. Further, wrinkles may easily form due to the accumulation and swelling of ink in the transfer paper  100 . Consequently, this invention is particularly useful for the transfer paper  100 , which is thin. 
     The entire disclosure of Japanese Patent Application No.2015-23891, filed Feb. 10, 2015 is expressly incorporated by reference herein.