JP2006082245A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance processing capacity of a printer at the time of recording a plurality of images while preventing waste of recording medium and deterioration of image due to variation in load during transfer of the recording medium, and to cut the recording medium at an proper position. <P>SOLUTION: A sheet unrolled from a sheet feeding section 40 is transferred toward the downstream side in the transfer direction while opposing thermal heads 71a-73a in a print section 70 without printing a color image. Transfer of the sheet is stopped at a moment in time when the sheet long enough to entirely printing a plurality of images included in one order is transferred to the downstream side of the print section 70 in the transfer direction. Subsequently, the plurality of color images are printed continuously by the thermal heads 71a-73a in the print section 70 while transferring the sheet reversely toward the upstream side in the transfer direction by a transfer pair roller 34 arranged on the upstream side of the print section 70 in the transfer direction. Pressure contact pair roller 36 and a loop forming pair roller 37 arranged to hold a cutting section 50 between are coupled through a coupling belt 58. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printer that records an image on a recording medium.

  Various techniques are known for printers capable of recording color images on a recording medium. For example, Patent Document 1 includes three thermal heads capable of individually recording each of yellow, magenta, and cyan colors, and the three recording heads that are drawn from the recording paper roll are conveyed in the paper feeding direction. A one-pass color thermal printer that records a color image with a thermal head is disclosed.

  Patent Document 2 discloses a 3-pass color thermal printer. In such a printer, a color thermal recording paper having a length of one frame drawn from a recording paper roll is sent out so as to face one thermal head, and then a yellow image is recorded while being pulled back, and then the recording paper. Are sent and pulled back alternately, and a magenta image is recorded at the second pull back, and a cyan image is recorded at the third pull back.

Patent Document 3 is provided with three thermal heads of yellow, magenta, and cyan. After the recording paper drawn from the recording paper roll is conveyed in the paper feeding direction and the print preparation is completed, the recording paper is loaded. A one-pass color thermal printer that records a color image of one frame while being conveyed in the pull-back direction is disclosed. In such a printer, when a color image of one frame is recorded, the recording paper is conveyed again in the paper feeding direction and cut at the rear end portion of the color image. Then, the recording paper on which the color image is recorded is discharged, and the next one-frame color image is recorded while the recording paper that has been prepared for printing is conveyed in the pull-back direction.
Japanese Patent Application Laid-Open No. 8-174476 JP-A-9-99572 JP 2001-246769 A

  In the printer described in Patent Document 1, a color image can be recorded only by transporting the recording paper in one direction without transporting the recording paper back and forth. However, in such a printer, when the three thermal heads are pressed against the recording paper in order from the one where the recording paper has reached the printing position, the image is deteriorated due to load fluctuations during conveyance of the recording paper. Sometimes. Therefore, in such a printer, in order to prevent the deterioration of the image, the recording of the color image is started after all the three thermal heads are pressed against the recording paper. For this reason, the portion between the thermal head in the vicinity of the leading edge of the recording paper, that is, the length between the most upstream thermal head and the most downstream thermal head in the paper feeding direction from the leading edge of the recording paper is stretched between the thermal heads. Recording of a color image is started. For this reason, there is a problem in that an image is not formed in the length portion where the recording paper is stretched and a blank portion is formed.

  On the other hand, in the printers described in Patent Document 2 and Patent Document 3, a color image can be recorded even in the vicinity of the leading end of the recording paper, so that it is possible to prevent the recording paper from being wasted. Here, in the printer described in Patent Document 3, when the recording paper is conveyed in the pullback direction, all three thermal heads are pressed against the recording paper, so that the image is caused by load fluctuations during the conveyance of the recording paper. Is rarely worse.

  However, in the printer of Patent Document 2, it is necessary to repeat feeding and pulling of the recording paper three times in order to record a single color image. Further, in the printer of Patent Document 3, it is necessary to feed and pull back the recording paper once for each color image of one frame. Therefore, in order to record a color image of a plurality of frames in these printers, the reciprocating conveyance of the recording paper has to be repeated many times.

  Here, in the printers of Patent Document 2 and Patent Document 3, a pair of transport rollers is disposed between the recording paper roll and the thermal head, and the transport direction of the recording paper is switched by switching the driving direction of the pair of transport rollers. Is changed to either the paper feed direction or the pull back direction. Therefore, in order to record a color image of a plurality of m frames (m is an integer of 2 or more), the printer of Patent Document 2 must reciprocate the recording paper 3 m times, and the driving direction of the conveying roller pair is changed. It is necessary to switch only (6m-1) times. In the printer of Patent Document 3, the recording paper must be reciprocated and conveyed m times, and the driving direction of the conveying roller pair needs to be switched only (2m-1) times.

  As described above, when the driving direction of the conveying roller pair is switched, a time-related conveying loss occurs due to the switching. Therefore, if the number of times of switching the driving direction of the conveying roller pair is increased, the time-related conveying loss is increased accordingly, and the processing capability of the printer is lowered.

  Further, when a plurality of images are recorded on the recording paper, a margin is often formed near the leading edge of the recording paper or between the plurality of images. In this case, the recording paper is formed at the end of each image. Need to be cut off. Here, when the recording paper is transported to the cutting position on the cutting blade by a pair of transport rollers (a pair of transport rollers in the forward direction of the reciprocating transport as viewed from the cutting blade) disposed in front of the cutting blade. In other words, the cutting position of the recording sheet is controlled by detecting the conveying amount of the recording sheet by the pair of conveying rollers from the number of rotations. However, when cutting the margin formed near the leading edge of the recording paper, the recording paper is no longer clamped by the conveying roller pair, so the recording paper The cutting position cannot be controlled. Therefore, the recording paper cannot be cut at an appropriate position.

  Accordingly, a main object of the present invention is to improve the processing capability when recording a plurality of images while preventing image deterioration due to waste of the recording medium and load fluctuation during conveyance of the recording medium. Another object of the present invention is to provide a printer capable of cutting a recording medium at an appropriate position.

Means for Solving the Problems and Effects of the Invention

  The printer according to the present invention includes an image recording unit capable of recording an image on a recording medium, a supply unit storing a long recording medium, a cutting mechanism capable of cutting the recording medium, and recording on a downstream side of the cutting mechanism. By sandwiching the medium, the recording medium is opposed to the image recording unit while facing the first direction from the supply unit to the image recording unit, and in a second direction that is opposite to the first direction. A first conveying roller pair capable of conveying, a second conveying roller pair capable of conveying the recording medium in the second direction by sandwiching the recording medium upstream of the cutting mechanism, and the first A rotation number detection unit capable of detecting the rotation number of the pair of conveyance rollers, a conveyance amount detection unit configured to detect a conveyance amount of the recording medium based on the rotation number detected by the rotation number detection unit, and the first conveyance The roller pair and the second transport roller A coupling mechanism that couples the pair of rollers so that the respective conveying speeds are the same, and the recording medium moves in the first direction until the leading end of the recording medium reaches a position away from the image recording unit in the first direction. Is conveyed in the second direction by the first conveyance roller pair and the conveyance control means for controlling the first conveyance roller pair so that the first conveyance roller pair is conveyed in the second direction. An image recording control unit that controls the image recording unit and a recording medium that is conveyed in the second direction are detected by the conveyance amount detection unit so that a plurality of images are recorded on the recording medium by the image recording unit. Cutting control means for controlling the cutting mechanism so as to be cut at a timing based on the transported amount, and the cutting control means is connected to the first transport roller pair and the cutting from the front end of the recording medium. In the mechanism When the recording medium is cut at a position that is longer than the distance from the cutting position, the timing is based on the conveyance amount of the recording medium by the first conveyance roller pair detected by the conveyance amount detection unit. In the case where the recording medium is cut and the recording medium is cut at a position away from the leading end of the recording medium by a distance shorter than the distance between the first conveying roller pair and the cutting position in the cutting mechanism, the conveyance The recording medium is cut at a timing based on the conveyance amount of the recording medium by the second conveyance roller pair detected by the amount detection means.

  Note that “the leading end of the recording medium reaches a position away from the image recording unit in the first direction” means that “the recording medium is conveyed in the first direction from the supply unit to the image recording unit and recorded. This means that the leading end of the medium reaches a position downstream of the image recording unit. In this specification, “upstream side” and “downstream side” relate to a first direction from the supply unit toward the image recording unit.

  According to this configuration, a plurality of images can be recorded on the recording medium conveyed in the second direction after the recording medium is conveyed in the first direction from the supply unit toward the image recording unit. Therefore, an image can be recorded in the vicinity of the leading end of the recording medium (the region from the leading end of the recording medium portion that is transported in the first direction and then fed back in the second direction), and the recording medium is being transported. It is possible to suppress the deterioration of the image due to the load fluctuation. Further, even when a plurality of images are recorded on the recording medium, it is only necessary to reciprocate the recording medium once, and it is only necessary to switch the recording medium conveyance direction in the first conveyance roller pair once. The time-based transport loss can be reduced. As a result, when a plurality of images are recorded on a recording medium, it is possible to improve the processing capability of the printer while preventing image deterioration due to waste of the recording medium and load fluctuation during conveyance of the recording medium.

  Further, when the length of the recording medium from the leading end of the recording medium to the portion to be cut is shorter than the distance between the first conveying roller pair and the cutting position in the cutting mechanism, the recording medium is moved by the first conveying roller pair. Even when the recording medium is not sandwiched and the cutting position of the recording medium cannot be controlled based on the transport amount of the recording medium by the first transport roller pair, it is based on the transport amount of the recording medium by the second transport roller pair that sandwiches the recording medium. Thus, the cutting position of the recording medium can be controlled. Therefore, the recording medium can be cut at an appropriate position.

  The printer of the present invention includes an image recording unit capable of recording an image on a recording medium, a supply unit storing a long recording medium, a cutting mechanism capable of cutting the recording medium, and the recording medium facing the image recording unit. A first conveying roller pair capable of conveying in a first direction from the supply unit to the image recording unit and a second direction opposite to the first direction, and more than the cutting mechanism. By sandwiching the recording medium on the upstream side, the recording medium is sandwiched between the second conveying roller pair capable of conveying the recording medium in the second direction, and the cutting mechanism and the first conveying roller pair. By doing so, the third conveyance roller pair capable of conveying the recording medium in the second direction, the rotation number detection means capable of detecting the rotation number of the third conveyance roller pair, and the rotation number detection means Recording medium based on detected rotation speed A conveyance amount detecting means for detecting a conveyance amount; a coupling mechanism for coupling the second conveyance roller pair and the third conveyance roller pair so that the conveyance speeds thereof are the same; The first conveyance roller pair is controlled so that the recording medium is conveyed in the first direction after being conveyed in the first direction until reaching a position away from the image recording unit in the first direction. An image for controlling the image recording unit such that a plurality of images are recorded by the image recording unit on a recording medium that is conveyed in the second direction by the first conveyance roller pair and the conveyance control unit. A recording control unit; and a cutting control unit that controls the cutting mechanism so that the recording medium conveyed in the second direction is cut at a timing based on the conveyance amount detected by the conveyance amount detection unit. And said The cutting control means detects the conveyance amount when the recording medium is cut at a position longer than the distance between the third conveyance roller pair and the cutting position in the cutting mechanism from the leading edge of the recording medium. The recording medium is cut at a timing based on the conveyance amount of the recording medium by the third conveyance roller pair detected by the means, and the third conveyance roller pair and the cutting position in the cutting mechanism are separated from the leading end of the recording medium. When the recording medium is cut at a position shorter than the distance, the recording medium is cut at a timing based on the conveyance amount of the recording medium by the second conveyance roller pair detected by the conveyance amount detection unit. It is characterized by doing.

  Note that “the leading end of the recording medium reaches a position away from the image recording unit in the first direction” means that “the recording medium is conveyed in the first direction from the supply unit to the image recording unit and recorded. This means that the leading end of the medium reaches a position downstream of the image recording unit. In this specification, “upstream side” and “downstream side” relate to a first direction from the supply unit toward the image recording unit.

  According to this configuration, a plurality of images can be recorded on the recording medium conveyed in the second direction after the recording medium is conveyed in the first direction from the supply unit toward the image recording unit. Therefore, an image can be recorded in the vicinity of the leading end of the recording medium (the region from the leading end of the recording medium portion that is transported in the first direction and then fed back in the second direction), and the recording medium is being transported. It is possible to suppress the deterioration of the image due to the load fluctuation. Further, even when a plurality of images are recorded on the recording medium, it is only necessary to reciprocate the recording medium once, and it is only necessary to switch the recording medium conveyance direction in the first conveyance roller pair once. The time-based transport loss can be reduced. As a result, when a plurality of images are recorded on a recording medium, it is possible to improve the processing capability of the printer while preventing image deterioration due to waste of the recording medium and load fluctuation during conveyance of the recording medium. Further, a loop of the recording medium can be formed between the first conveyance roller pair and the third conveyance roller pair. Accordingly, by forming a loop between the first conveyance roller pair and the third conveyance roller pair before cutting by the cutting mechanism, image recording is deteriorated due to vibration caused by the cutting. Can be prevented.

  Further, when the length of the recording medium from the leading end of the recording medium to the portion to be cut is shorter than the distance between the third conveying roller pair and the cutting position in the cutting mechanism, the recording medium is moved by the third conveying roller pair. Even when the recording medium is not nipped and the cutting position of the recording medium cannot be controlled based on the conveyance amount of the recording medium by the third conveyance roller pair, it is based on the conveyance amount of the recording medium by the second conveyance roller pair that nips the recording medium. Thus, the cutting position of the recording medium can be controlled. Therefore, the recording medium can be cut at an appropriate position.

  In the printer according to the aspect of the invention, the first conveyance roller pair can convey the recording medium in the second direction by applying a conveyance force to the recording medium between the supply unit and the image recording unit. There may be.

  According to this configuration, when a plurality of images are recorded on the recording medium conveyed in the second direction, it is possible to effectively suppress deterioration of the image due to load fluctuations during conveyance of the recording medium. Can do.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of a printer according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a schematic configuration of a printing unit of the printer of FIG. FIG. 3 is a diagram showing a configuration in the vicinity of the cutting position in the cutting mechanism included in the printing unit of FIG. FIG. 4 is a diagram for explaining the operation of the conveying roller pair and the feeding roller pair of the printer of FIG. FIG. 5 is a block diagram of a main part of the printer of FIG. 1 and a control device to which these are connected.

  A thermal sublimation thermal printer 1 shown in FIG. 1 (hereinafter referred to as “printer 1”) includes an operation unit 10, a control device 20, and a printing unit 30. The operation unit 10 is for an operator to operate the printer 1 and has a display 11 for displaying various information about the printer 1 and notifying the operator. Here, in the present embodiment, a touch panel method is adopted for the operation unit 10, and an operation screen 12 including various buttons is displayed on the display 10. Accordingly, the operator can execute an operation on the printer 1 by touching the operation screen 12.

  The control device 20 receives input from the operation unit 10 and controls various operations in the printer 1. In addition, the control device 20 has a plurality of data input units 20a for acquiring print data from various storage media such as a card slot and a disk drive. The storage medium may be any medium that can store print data, such as a CD-ROM or a memory card.

  The operation unit 10 and the control device 20 are fixedly arranged on the upper surface of a housing 30 a that houses the print unit 30. Here, the display surface of the display 11 of the operation unit 10 and the storage medium insertion surface of the data input unit 20a of the control device 20 substantially coincide with the front of the printer 1 (housing 30a) (the surface on the left front side in FIG. 1). ing. Therefore, it is easy for the operator heading to the front of the printer 1 to operate the display 11 and the data input unit 21.

  The housing 30a has a substantially rectangular parallelepiped shape, and the lateral width (front width) D1 is smaller than the depth D2. Therefore, the printer 1 can be installed even in a relatively narrow space. Furthermore, an opening 95 is formed on the front surface of the housing 30a for drawing out a print box 96 (described later) housed in the housing 30a to the outside of the housing 30a.

  As shown in FIG. 2, the print unit 30 includes a paper supply unit 40 that holds a paper wound in a roll shape and a paper winding unit that winds up the paper that has been unwound from the paper supply unit 40. Between the take-up unit 80 and the paper supply unit 40 and the paper take-up unit 80, there is a transport mechanism 38 that can transport the paper along a transport path curved in one direction. A cutting unit 50, an overcoat unit 60, and a printing unit 70 are disposed between the paper supply unit 40 and the paper winding unit 80 from the upstream side to the downstream side of the transport path. A print box 96 is provided near the conveyance path between the paper supply unit 40 and the cutting unit 50.

  In the present embodiment, “paper transport direction (transport direction)” means a direction from the paper supply unit 40 toward the paper winding unit 80. Further, the “paper front end” and the “image front end” mean the end on the downstream side of the paper or the image transport direction, and the “paper rear end” and “image rear end” The term “edge” means an end portion on the upstream side of the sheet or image in the conveying direction.

  The paper supply unit 40 has a magazine case 41 provided in the uppermost stream of the transport path, and a long paper is wound around the rotation shaft 43 so that the printing surface is on the outside. The wound winding part 45 is loaded. Here, the rotating shaft 43 is driven to rotate counterclockwise in FIG. 2 when the sheet is unwound from the sheet supply unit 40 and conveyed toward the downstream side in the conveying direction by the motor 43a (see FIG. 5). When the unwound paper is taken up by the paper supply unit 40, it is rotated clockwise in FIG. The rotary shaft 43 is connected to a shaft (not shown) that is rotationally driven by a motor 43a via a one-way clutch 43c having the same function as one-way clutches 34c and 35c described later.

  The transport mechanism 38 is arranged in order from the upstream side in the transport direction, and includes a pair of paper feed rollers 31 that can transport the paper unrolled from the winding unit 45 of the paper supply unit 40 upward, and the cutting unit 50. Are also arranged on the upstream side in the transport direction and turn roller pair 32 that changes the transport direction of the paper that is transported upward, and a pair of pressure rollers that are disposed in the vicinity of the upstream side of cutting section 50 and can press the paper. 36, a loop forming roller pair 37 that is disposed in the vicinity of the downstream side of the cutting unit 50 and can press the paper, and a transport roller pair 34 that is disposed on the upstream side in the transport direction of the printing unit 70 and can transport the paper. And a feed roller pair 35 that is disposed downstream of the printing unit 70 in the transport direction and feeds the paper transported downstream of the print unit 70 in the transport direction into the paper winding unit 80. is doing

  In the present embodiment, the paper feed roller pair 31, the turn roller pair 32, the pressure roller pair 36, the loop forming roller pair 37, and the feeding roller pair 35 are made of resin rollers, and the transport roller pair 34 is It is composed of a metal roller.

  Here, a pair of feed rollers 31, a pair of turn rollers 32, a pair of pressure rollers 36, a pair of loop forming rollers 37, a pair of transport rollers 34 and a pair of feed rollers 35 have a circumference (indicated by a two-dot chain line in FIG. 2). (It is drawn). As can be seen from FIG. 2, the head portions 61 and 71 to 73 of the overcoat portion 60 and the printing portion 70 are also arranged along the circumference, and the paper supply portion 40 and the paper take-up portion 80 are It arrange | positions inside the said periphery.

  The paper feed roller pair 31, the loop forming roller pair 37, the transport roller pair 34, and the feed roller pair 35 are connected to motors 31a, 37a, 34a, and 35a (see FIG. 5) controlled by the transport control unit 27a (see FIG. 5). They are connected to each other and can be driven to rotate.

  The printing unit 30 includes an encoder 33 a that can detect the rotation speed of the conveyance roller pair 34 and an encoder 33 b that can detect the rotation speed of the loop forming roller pair 37. Here, the conveyance roller pair 34 and the loop forming roller pair 37 are driven and rotated by the motors 34a and 37a to convey the sheet, and are rotated in accordance with the sheet conveyed by the feed roller pair 35 and the like. The state can be taken. The encoders 33a and 33b can detect the rotation speeds of the transport roller pair 34 and the loop forming roller pair 37 regardless of the state of the transport roller 34 and the loop forming roller pair 37.

  The cutting part 50 is disposed between the pressure roller pair 36 and the loop forming roller pair 37. The cutting unit 50 includes a rolling cutter 51 disposed above the conveyance path, a fixed blade 52 disposed below the conveyance path, and a chip box 53.

  The rolling cutter 51 has a disk shape, and a blade is formed on the entire circumference of the rolling cutter 51. The center of the rolling cutter 51 is held by a shaft 51a. The rolling cutter 51 is connected to a drive mechanism 55 (see FIG. 5) controlled by the cutting control unit 27c via a shaft 51a. The drive mechanism 55 rotates and drives the rolling cutter 51 via the shaft 51a, and moves forward or backward along the sheet conveyance path along a direction orthogonal to the sheet (in the direction orthogonal to the paper surface in FIG. 2). . On the other hand, the fixed blade 52 is a rectangular blade that is disposed so as to be orthogonal to the paper transport path and is longer than the entire width of the paper transport path. Here, chamfering is applied to a portion of the tip of the fixed blade 52 opposite to the rolling cutter 51.

  Accordingly, when the sheet is placed at the cutting position in the cutting unit 50, the cutting control unit 27c controls the driving mechanism 55 to rotate the rolling cutter 51 and move it along the width direction of the sheet. The sheet is cut by the interaction between 51 and the fixed blade 52. In the printer 1 according to the present embodiment, as will be described later, the cutting unit 50 cuts the paper at the leading edge and the trailing edge of each image.

  The chip box 53 is disposed below the rolling cutter 51 and the fixed blade 52. Therefore, when the paper is cut at the leading edge or the trailing edge of each image and the margin is cut, the margin is stored in the chip box 53.

  Here, the configuration in the vicinity of the cutting position in the cutting unit 50 will be described with reference to FIG.

  The pressure roller pair 36 includes a roller 36d disposed below the paper conveyance path and a roller 36e disposed above the paper conveyance path so that the paper can be crimped between the roller 36d. Here, the roller 36e is movable in a direction away from or close to the roller 36d (in the vertical direction in FIG. 3), and is a crimping position (position indicated by a solid line in FIG. 3) for crimping the paper with the roller 36d. ) And a retracted position (a position indicated by a broken line in FIG. 3) that is not crimped.

  On the other hand, the loop forming roller pair 37 includes a driving roller 37d disposed below the paper conveyance path and a driven roller 37e disposed so that the paper can be crimped between the driving roller 37d above the paper conveyance path. have. Here, the drive roller 37d is rotationally driven by the motor 37a (see FIG. 5) as described above.

  A connecting belt 58 is stretched between the rotation shaft 37 f of the drive roller 37 d of the loop forming roller pair 37 and the rotation shaft 36 f of the roller 36 d of the pressure roller pair 36. Therefore, the rotation shaft 36f and the rotation shaft 37f rotate at the same rotation speed. Accordingly, when the driving roller 37a of the loop forming roller pair 37 is rotationally driven, the rotation is transmitted to the roller 36d of the pressure-bonding roller pair 36 via the connecting belt 58, so that the driving roller 37a and the roller 36d Rotate to have the same transport speed. It should be noted that the distance between the pressure roller pair 36 and the loop forming roller pair 37 is shorter than the minimum print size length so that the entire print size can be conveyed.

  A pressing member 39 is disposed between the conveying roller pair 34 and the loop forming roller pair 37 as shown in FIG. The pressing member 39 can be moved in a direction (vertical direction in FIG. 3) perpendicular to the sheet conveyance path by an elevating mechanism 39a (see FIG. 5) controlled by the position control unit 27d. Therefore, the pressing member 39 has a protruding position (a position indicated by a two-dot chain line in FIG. 3) where the leading end pushes the sheet upward, and a retracting position where the leading sheet is not pushed upward while the leading end is maintained in a horizontal state. (Position indicated by a solid line in FIG. 3). Further, a position sensor 92 that detects that a loop having a predetermined size is formed by placing the pressing member 39 at the protruding position is provided above the sheet conveyance path.

  The overcoat unit 60 is disposed on the downstream side of the conveyance roller pair 34 in the conveyance direction. The overcoat part 60 has one head part 61. The head unit 61 is for performing a colorless and transparent overcoat (OC) on the surface of the paper on which an image is printed. Thus, by overcoating the surface of the paper, the light resistance of the image printed on the paper can be improved and the surface of the paper can be protected. Further, by selecting the material of the overcoat, the gloss of the print can be improved and a high-quality print can be provided.

  The printing unit 70 is disposed between the overcoat unit 60 and the feed roller pair 35. The printing unit 70 has three head units 71 to 73. The head portions 71 to 73 are for performing printing corresponding to cyan (C), magenta (M), and yellow (Y), respectively. Here, in the printer 1, a head unit 71 corresponding to cyan, a head unit 72 corresponding to magenta, and a head unit 73 corresponding to yellow are provided in this order from the upstream side in the transport direction to the downstream side in the transport direction. In the printer 1, the transport roller pair 34 is disposed on the upstream side in the transport direction of the overcoat unit 60 and the printing unit 70, and the feed roller pair 35 is disposed on the downstream side in the transport direction.

  In the printer 1 of the present embodiment, when the paper unrolled from the paper supply unit 40 is conveyed toward the downstream side in the conveyance direction, the overcoat in the overcoat unit 60 and the image in the printing unit 70 are displayed. When printing is not performed, and the paper once wound by the paper winding unit 80 disposed downstream of the printing unit 70 in the transport direction is fed back toward the upstream side of the transport direction, the printing unit 70 The image is printed and overcoating in the overcoat unit 60 is performed. Therefore, the printer 1 can print an image on the paper surface in the order of yellow, magenta, and cyan, and can further overcoat the paper surface on which the image is printed.

  Next, a schematic configuration of the head units 61 and 71 to 73 will be described. In addition, since the structure of the head parts 61 and 71 to 73 is the same, only the head part 73 will be described in detail here.

  The head unit 73 includes a thermal head 73a having a large number of heating elements (not shown) arranged over the entire width of the paper conveyance path, and a tip portion of the thermal head 73a (in the vicinity of the paper conveyance path and the heating elements are arranged). A platen roller 73b facing the other end, a tape-like ribbon 73c having an ink area to which ink corresponding to yellow is attached, a ribbon supply roller 73d around which a ribbon 73c before printing is wound, and a post-printing ribbon A ribbon take-up roller 73e for taking up the ribbon 73c.

  Here, the thermal head 73a can be moved back and forth with respect to the paper transport path by an elevating mechanism 73f (see FIG. 5). Therefore, the thermal head 73a can selectively take the print position where the ribbon 73c and the paper are pressed against each other and the retracted position where the paper 73 is not pressed between the vicinity of the tip and the platen roller 73b.

  In the head unit 73, when the paper is conveyed between the thermal head 73a and the platen roller 73b in a state where the thermal head 73a is disposed at the printing position, the ink of the ribbon 73c heated by the thermal head 73a. Thus, an image corresponding to yellow can be printed on the paper. At this time, when the sheet is conveyed between the thermal head 73a and the platen roller 73b, the ribbon 73c is also moved from the ribbon supply roller 73d toward the ribbon take-up roller 73e as the sheet is conveyed. Sent.

  The head unit 61 and the head units 71 and 72 are similar to the head unit 73 in that the thermal heads 61a, 71a and 72a, the platen rollers 61b, 71b and 72b, the ribbons 61c, 71c and 72c, and the ribbon supply roller 61d. 71d, 72d, ribbon take-up rollers 61e, 71e, 72e, and elevating mechanisms 61f, 71f, 72f, respectively.

  Here, in the head unit 61 and the head units 71 and 72, ink corresponding to colorless and transparent, cyan and magenta, respectively, instead of the tape-like ribbon 73c having an ink region to which ink corresponding to yellow of the head unit 73 is attached. Tape-shaped ribbons 61c, 71c, and 72c having an ink region to which are attached are used.

  A pair of guides 75 a to 75 c are disposed between the head portion 61 of the overcoat portion 60 and the head portions 71 to 73 of the printing portion 70, respectively. Each of the pair of guides 75a to 75c includes two plate-like members, and guides the sheet (mainly the leading end portion of the sheet) conveyed between the head units 61 and 71 to 73, respectively. is there. Accordingly, the pair of guides 75a to 75c are arranged so as to face each other with a predetermined interval across the sheet conveyance path.

  The paper take-up unit 80 has a storage case 81 provided on the most downstream side of the transport path. The storage case 81 has a substantially cylindrical shape, and a part of the storage case 81 opens as a paper insertion opening 82. In the present embodiment, as shown in FIG. 2, the central angle of the portion that becomes the insertion port 82 is about 90 degrees, and one edge 82a is in the vicinity of the left end of the storage case 81, and the other The edge portion 82 b is in the vicinity of the upper end portion of the storage case 81.

  Here, the feeding roller pair 35 is disposed in the vicinity of the upper portion of the edge portion 82 a of the storage case 81, and the sheet conveyed downward by the feeding roller pair 35 is located in the storage case 81 from the vicinity of the end portion 82 a of the insertion port 82. Inserted into. The paper inserted into the paper winding unit 80 is guided by contacting the inner peripheral surface of the storage case 81. As a result, in the storage case 81, the paper is wound in order from the leading edge of the paper so that the printing surface becomes the outer surface according to the curl of the paper. The storage case 81 is rotatably provided with four winding rollers 83a to 83d. A part of each of the winding rollers 83 a to 83 d protrudes inward from the inner peripheral surface of the storage case 81. Accordingly, since the frictional force when the paper comes into contact with the inner peripheral surface of the storage case 81 is reduced, the paper is prevented from being damaged.

  The print box 96 is for discharging paper (print) on which each image cut by the cutting unit 50 is printed after the printing of the image in the printing unit 70 and the overcoat in the overcoat unit 60 is performed. It is. The print box 96 is a box-shaped member having an upper end opened, and is supported by a support shaft 97 at the lower end to be rotatable. Accordingly, the print box 96 has a state in which the print box 96 is housed in the housing 30a (shown by a solid line in FIG. 2) and an upper end portion of the print box 96 through the opening 95 provided on the front surface (right surface in FIG. 2). A state in which the vicinity is pulled out of the housing 30a (a state indicated by a broken line in FIG. 2) can be taken. Therefore, the operator can easily take out the paper on which each image is printed by pulling out the upper end portion of the print box 96 from the front of the printer 1 (housing 30a).

  A sorting mechanism (not shown) is provided above the print box 96 so as to be close to the transport path upstream of the turn roller pair 32 in the transport direction. In this sorting mechanism, the paper is fed back toward the upstream side in the transport direction when the paper is wound around the paper supply unit 40 and when the paper on which each image is printed is discharged to the print box 96. It is possible to switch the paper transport path. Therefore, by controlling the sorting mechanism, only the paper on which each image is printed can be stored in the print box 96.

  Further, an image detection sensor 90 that can detect an end portion (mainly a rear end portion of the image) of an image printed on a sheet conveyed along the conveyance path, on the upstream side of the cutting unit 50 in the conveyance direction. Is provided. On the other hand, a paper detection sensor 91 that can detect the edge of the paper is provided upstream of the overcoat unit 60 in the transport direction. In the present embodiment, the end of the overcoat unit 60 on the upstream side in the conveyance direction and the detection position by the paper detection sensor 91 substantially coincide with each other.

  Next, operations of the conveying roller pair 34 and the feeding roller pair 35 will be described with reference to FIG. 4A illustrates the operation of the transport roller pair 34 and the feed roller pair 35 when the paper is transported downstream in the transport direction, and FIG. 4B illustrates that the paper is reversed upstream in the transport direction. The operations of the conveying roller pair 34 and the feeding roller pair 35 during feeding are shown. As shown in FIG. 4, the conveyance roller pair 34 includes a driving roller 34d and a driven roller 34e. The drive roller 34d is connected to a shaft 34b that is rotationally driven by a motor 34a via a one-way clutch 34c. Similarly, the feed roller pair 35 includes a drive roller 35d and a driven roller 35e, and the drive roller 35d is connected to a shaft 35b that is rotationally driven by a motor 35a via a one-way clutch 35c.

  Since the one-way clutches 34c and 35c have the same function, the function of the one-way clutch 34c will be described here. The one-way clutch 34c is fixed to the driving roller 34d and rotates together with the driving roller 34d. When the drive roller 34d rotates faster than the rotational speed of the shaft 34b, the rotational force of the shaft 34b is not transmitted to the drive roller 34d, and the drive roller 35d rotates idly with respect to the shaft 34b. In other cases, the rotational force of the shaft 34b is transmitted to the drive roller 34d via the one-way clutch 34c, and the shaft 34b and the drive roller 34d rotate together.

  Therefore, when the conveyance roller pair 34 holds the sheet, the conveyance speed of the sheet is slower than the conveyance speed of the sheet based on the rotational force of the conveyance roller pair 34 driven by the motor 34a. Is transmitted to the conveying roller pair 34. Then, the sheet is transported with a transport force applied by the transport roller pair 34. On the other hand, when the paper conveyance speed is faster than the paper conveyance speed based on the rotational force of the conveyance roller pair 34 driven by the motor 34a, the driving force of the motor 34a is not transmitted to the conveyance roller pair 34 and is conveyed. The roller pair 34 is idle. That is, the transport roller pair 34 is driven to rotate at a rotational speed corresponding to the paper transport speed.

  Here, the sheet conveying speed based on the rotational force of the conveying roller pair 34 driven by the motor 34a is V1, and the sheet conveying speed based on the rotational force of the feeding roller pair 34 driven by the motor 35a is V2. Consider the case of transporting a sheet downstream in the transport direction with reference to (a). At this time, as will be described later, after the leading edge of the paper reaches the feed roller pair 35 and is nipped, the drive of the transport roller pair 34 is stopped, and the transport speed V1 becomes zero. On the other hand, the feed roller pair 35 is rotationally driven by the driving force of the motor 35a being transmitted through the shaft 35b and the one-way clutch 35c. Since the sheet sandwiched between the transport roller pair 34 is transported at the transport speed V2, the transport roller pair 34 is idled by the function of the one-way clutch 34c.

  Next, with reference to FIG. 4B, consider a case where the paper is fed back upstream in the transport direction. At this time, as will be described later, since the driving of the feed roller pair 35 is stopped, the conveyance speed V2 becomes zero. On the other hand, the conveying roller pair 34 is rotationally driven by the driving force of the motor 34a being transmitted through the shaft 34b and the one-way clutch 34c. Since the sheet sandwiched between the feed roller pair 35 is reversely fed at the conveyance speed V1, the feed roller pair 35 rotates idly by the function of the one-way clutch 35c.

  The pair of paper feed rollers 31 is also connected to a shaft (not shown) that is rotationally driven by a motor 31a via a one-way clutch 31c having the same function as the one-way clutches 34c and 35c described above. Accordingly, the paper feed roller pair 31, the transport roller pair 34, and the feed roller pair 35 are configured to remove the paper unrolled from the paper supply unit 40 by individually controlling the motors 31a, 34a, and 35a by the transport control unit 27a. The sheet can be conveyed downstream in the conveying direction and taken up by the paper take-up unit 80, and the paper once taken up in the paper take-up unit 80 can be unwound and unwound from the paper take-up unit 80. The printed paper can be fed back toward the upstream side in the transport direction.

  As shown in FIG. 5, the control device 20 includes a motor 43 a that drives the rotation shaft 43 of the paper supply unit 40, a paper feed roller pair 31, a loop forming roller pair 37, a transport roller pair 34, and a feed roller pair 35. Motors 31 a, 37 a, 34 a, 35 a that are respectively driven, an encoder 33 a that detects the rotational speed of the conveying roller pair 34, an encoder 33 b that detects the rotational speed of the loop forming roller pair 37, and a roller 36 e of the pressure roller pair 36. Elevating mechanism 33f, elevating mechanism 39a of pressing member 39, driving mechanism 55 of rolling cutter 51 of cutting unit 50, elevating mechanisms 61f, 71f of thermal heads 61a, 71a to 73a of overcoat unit 60 and printing unit 70 73f and drivers 61g, 71g to 73g, image detection sensor 90, paper detection sensor 91, position detection A sensor 92, an operation unit 10 are connected.

  The control device 20 includes hardware such as a CPU, a ROM, and a RAM controlled by appropriate software, and includes a maximum winding amount storage unit 21, a print information storage unit 22, and a necessary winding amount calculation unit. 23, a comparison unit 24, a winding amount determination unit 25, a conveyance amount detection unit 26, a conveyance control unit 27a, a print control unit 27b, a cutting control unit 27c, and a position control unit 27d. Yes.

  The maximum winding amount storage unit 21 maximizes the maximum length of paper that can be transported downstream in the transport direction from the printing unit 70 when the paper is transported from the paper supply unit 40 toward the paper winding unit 80. It is memorized as a winding amount. The maximum winding amount is determined by the length of the conveyance path between the printing position by the head unit 73 arranged on the most downstream side in the conveyance direction of the printing unit 70 and the insertion port 82 of the sheet winding unit 80, and the sheet winding. This value is calculated by adding together the length of paper that can be taken up in the storage case 81 of the unit 80. The maximum winding amount is input to the maximum winding amount storage unit 21 by the operator.

  Here, the maximum winding amount largely varies depending on the size of the storage case 81. The length of paper that can be wound in the storage case 81 may be the maximum length of paper that can actually be stored in the storage case 81, or the maximum length of paper that can be stored in the storage case 81. It may be shorter than the length and can be set arbitrarily. Therefore, in the present embodiment, the length of the paper that can be wound in the storage case 81 used when the maximum winding amount is calculated is that the paper is not damaged or scratched in the storage case 81. The length of the range is set to be shorter than the maximum length of paper that can be stored in the storage case 81.

  The print information storage unit 22 stores various set values when an image is printed. Here, the set values include the print length of one frame for each print type (the length in the transport direction), the number of prints (the number of frames), the length of the margin formed between adjacent images, and the head heat dissipation. Includes additional length. As the print length of one frame for each print type, a plurality of values are stored for each of a plurality of print types such as a standard size and a panorama size, for example. As the number of prints, a value input for each order by the operator before printing is stored. Further, the length of the margin between the images and the additional length for heat radiation of the head are stored as values input by the operator before starting printing. The additional length is such that the temperatures of the thermal heads 71a, 72a, 73a that have generated heat for printing an image and the thermal head 61a that has generated heat for overcoating are substantially the same as the ambient temperature after energization. The sheet is set to such a length that the sheet faces each of the thermal heads 61a and 71a to 73a. In the present embodiment, the time required for each of the thermal heads 61a, 71a to 73a that have generated heat to be substantially the same as the ambient temperature, and the sheet to be fed back toward the upstream side in the transport direction. The additional length is calculated by the product with the conveyance speed.

  The necessary winding amount calculation unit 23 calculates the length of paper necessary for printing all of the plurality of images included in one order as the necessary winding amount. In other words, in order to print all of a plurality of images included in one order, before starting the printing of the image by the printing unit 70, a sheet having a length capable of printing these images is set to be longer than the printing unit 70. It is necessary to carry it downstream in the carrying direction. Accordingly, when the sheet is conveyed from the sheet supply unit 40 toward the sheet take-up unit 80, the printing position by the head unit 73 of the printing unit 70 is set in order to print all of the plurality of images included in one order. The length of the sheet to be conveyed beyond the above is calculated as the necessary winding amount.

  Here, the necessary winding amount will be described with reference to FIG. FIG. 6 is a diagram illustrating a state in which a plurality of images included in one order are printed in the vicinity of the leading edge of the paper. FIG. 6 shows a case where six images of the same print type are included in one order. As shown in FIG. 8, a region corresponding to the additional length z for heat radiation is provided in the vicinity of the leading end portion (left end portion in FIG. 6) of the sheet, and from there toward the upstream side (right side in FIG. 6). The area corresponding to the print length x and the area corresponding to the margin length y are alternately provided by the number n of prints.

Therefore, when the operator inputs the print type and the number of prints of an image included in one order before starting printing, the necessary winding amount calculation unit 23 is based on each value stored in the print information storage unit 22. Thus, the required winding amount L corresponding to one order is calculated by the following equation.
L = z + x * n + y * (n-1)

  The comparison unit 24 compares the required winding amount calculated by the required winding amount calculation unit 23 with the maximum winding amount stored in the maximum winding amount storage unit 21. Then, the comparison unit 24 obtains a comparison result regarding the magnitude relationship between the required winding amount and the maximum winding amount.

  The winding amount determination unit 25 is actually conveyed downstream of the printing unit 70 in the conveyance direction before the conveyance direction of the sheet is changed from the direction toward the downstream side in the conveyance direction to the direction toward the upstream side in the conveyance direction. The length of the sheet (actual winding amount), that is, the length of the sheet that is actually conveyed beyond the position facing the head unit 73 of the printing unit 70 is determined. Here, the winding amount determination unit 25 determines the winding amount based on the comparison result by the comparison unit 24. That is, when the comparison unit 24 obtains a comparison result that the required winding amount is equal to or less than the maximum winding amount, the winding amount determination unit 25 determines the actual winding amount as the necessary winding amount, On the other hand, when the comparison unit 24 obtains a comparison result that the required winding amount is longer than the maximum winding amount, the actual winding amount is determined as the maximum winding amount.

  The carry amount detection unit 26 detects the carry amount of the paper based on the number of rotations of the carry roller pair 34 detected by the encoder 33 a after the leading edge of the paper is detected by the paper detection sensor 91. That is, the transport amount detection unit 26 detects the length of the paper transported downstream in the transport direction from the position detected by the paper detection sensor 91. As a result, the conveyance amount detection unit 26 is conveyed downstream of the printing unit 70 in the conveyance direction before the sheet conveyance direction is changed from the direction toward the downstream side in the conveyance direction to the direction toward the upstream side in the conveyance direction. The length of the paper can be detected. As will be described later, after the leading edge of the sheet reaches the feed roller pair 35, the sheet is transported by the transport force applied from the feed roller pair 35 instead of the transport force applied from the transport roller pair 34. However, even in this case, the carry amount detection unit 26 always detects the carry amount of the paper based on the number of rotations of the carry roller pair 34.

  The conveyance amount detection unit 26 can detect the conveyance amount of the paper not only when the paper is conveyed toward the downstream side in the conveyance direction but also when the paper is conveyed toward the upstream side in the conveyance direction. . Therefore, when the paper transport direction is changed from the direction downstream in the transport direction to the direction upstream in the transport direction, the transport direction is changed from the transport amount downstream in the transport direction before the transport direction is changed. The leading end position of the sheet can be detected by subtracting the transport amount upstream in the transport direction after being performed.

  Further, when a loop is formed between the transport roller pair 34 and the loop forming roller pair 37, the transport amount detecting unit 26 is based on the number of rotations of the loop forming roller pair 37 detected by the encoder 33b. The sheet conveyance amount (for example, the sheet conveyance amount on the upstream side in the conveyance direction from the cutting position in the cutting unit 50) is detected. If no loop is formed between the transport roller pair 34 and the loop forming roller pair 37, the transport amount detected by the loop forming roller pair 37 and the transport amount detected by the transport roller pair 34 are as follows. Although the same, the position of the sheet at a certain timing is different by the distance between the conveying roller pair 34 and the loop forming roller pair 37.

  Further, when the leading end portion of the image (final image) printed closest to the leading end portion of the sheet is cut, the carry amount detection unit 26 presses after the trailing end portion of the final image is cut. The conveyance amount by the roller pair 36 is detected by detecting the number of rotations of the loop forming roller pair 37 connected to the pressure roller pair 36 via the connecting belt 58 by the encoder 33b.

  The conveyance control unit 27a controls the motors 43a, 31a, 37a, 34a, and 35a that drive the rotation shaft 43, the paper feed roller pair 31, the loop forming roller pair 37, the conveyance roller pair 34, and the feeding roller pair 35, The paper is conveyed from the paper supply unit 40 toward the paper take-up unit 80, and the paper is reversely fed from the paper take-up unit 80 toward the paper supply unit 40.

  The printing control unit 27b controls the raising / lowering timing and printing timing of the thermal head 61a of the overcoat unit 60 and the thermal heads 71a to 73a of the printing unit 70. Specifically, when the paper is transported downstream in the transport direction, the print control unit 27b sets the thermal heads 61a and 71a to 73a to the retracted position, and before the paper is fed back upstream in the transport direction, The raising / lowering timing is controlled so that the thermal heads 61a, 71a to 73a are set to the printing positions. Further, the print control unit 27b prints a plurality of images included in one order separated by the length of the blank portion on the paper being fed back upstream in the transport direction, and finally prints. The printing timing is controlled so that the image is not printed in the area corresponding to the additional length on the leading end side of the paper from the printed image. Further, the print control unit 27b controls the overcoat unit 60 so as to overcoat only the area where the image of the paper is printed.

  The cutting control unit 27 c controls the cutting timing at the cutting unit 50. In detail, the cutting control unit 27c detects the conveyance amount detection unit 26 to the upstream side in the conveyance direction after the sheet conveyance direction is changed from the direction toward the downstream in the conveyance direction to the direction toward the upstream in the conveyance direction. Based on the transport amount of the paper, it is detected that the rear end portion of the image printed most upstream in the transport direction has reached the cutting position in the cutting portion 50, and the rear end portion of the image is cut. The cutting unit 50 is controlled. In addition, the cutting control unit 27c detects the image based on the conveyance amount of the sheet upstream in the conveyance direction after the trailing edge of the image is detected by the image detection sensor 90, which is detected by the conveyance amount detection unit 26. It is detected that the leading end has reached the cutting position in the cutting unit 50, and the cutting unit 50 is controlled so that the leading end of the image is cut. Further, the cutting control unit 27c is downstream of the conveyance direction based on the conveyance amount of the sheet to the upstream side in the conveyance direction after the sheet is cut at the leading end portion of the image detected by the conveyance amount detection unit 26. It is detected that the rear end portion of the adjacent image on the side has reached the cutting position in the cutting portion 50, and the cutting portion 50 is controlled so that the rear end portion of the image is cut. Further, the cutting control unit 27c detects the leading edge of the final image based on the conveyance amount of the sheet upstream in the conveyance direction after the trailing edge of the final image is cut, which is detected by the conveyance amount detection unit 26. It is detected that the cutting position in the cutting unit 50 has been reached, and the cutting unit 50 is controlled so that the tip of the final image is cut.

  The position control unit 27d controls the lifting mechanism 39a of the pressing member 39. In other words, when the paper is cut at the leading edge and the trailing edge of the image (excluding the final image), the conveyance roller before cutting in order to prevent image printing from deteriorating due to vibration due to cutting. The position of the pressing member 39 is moved from the retracted position to the protruding position so that a loop is formed between the pair 34 and the loop forming roller pair 37. Further, when a loop having a predetermined size is formed by moving the pressing member 39 to the protruding position, the position of the pressing member 39 is moved from the protruding position to the retracted position.

  Next, an operation when the printer 1 prints an image will be described with reference to FIG. FIG. 7 is a flowchart showing an operation procedure for printing an image in the printer 1.

  First, the leading end of the sheet unwound by rotating the rotary shaft 43 from the paper winding unit 45 loaded in the paper supply unit 40 is transported only by the transport force applied from the paper feed roller pair 31. (Step S101). Then, the conveyance by the paper feed roller pair 31 is continued until the leading edge of the paper passes through the conveyance roller pair 34 and reaches the paper detection sensor 91 (step S102). Here, when the leading edge of the sheet is detected by the sheet detection sensor 91, a detection signal indicating that the leading edge of the sheet has been detected is transmitted from the sheet detection sensor 91 to the control device 20.

  In this way, when the leading edge of the paper reaches the paper detection sensor 91, the conveyance of the paper is stopped and a standby state is entered (step S103). At this time, if the thermal heads 61a and 71a to 73a are arranged at the print positions, the thermal heads 61a and 71a to 73a are moved to the retracted positions (step S104).

  Thereafter, when an order is received from the operator and the print type and the number of prints of an image included in one order are input (step S105), the print information storage unit prepares to start transporting the paper. Based on the information stored in 22, the necessary winding amount corresponding to the one order is calculated by the necessary winding amount calculation unit 23 (step S106). Then, the required winding amount is compared with the maximum winding amount stored in the maximum winding amount storage unit 21 by the comparison unit 24 (step S107). Based on the comparison result, the winding amount determination unit 25 determines the actual winding amount (step S108). In this way, after completion of the sheet conveyance preparation, the sheet is conveyed only by the conveyance force applied from the conveyance roller pair 34 (step S109). At this time, both the rotation shaft 43 and the paper feed roller pair 31 of the paper supply unit 40 are rotatable.

  Thereafter, in a state in which the thermal heads 61a and 71a to 73a are disposed at the retracted positions, the leading end of the sheet passes through the overcoat unit 60 and the print unit 70 without performing overcoat and image printing, and the feed roller The conveyance is continued only by the conveyance force applied from the conveyance roller pair 34 until the pair 35 is reached (step S110). When the leading edge of the sheet reaches the nipping roller pair 35 and is nipped, the sheet is thereafter conveyed only by the conveying force applied from the feeding roller pair 35 and is wound from the leading edge of the sheet. Are sequentially fed into the storage case 81 of the unit 80 (step S111). At this time, as the paper is fed into the storage case 81, the leading edge of the paper is guided to the inner peripheral surface of the storage case 81 and the take-up rollers 83 a to 83 d, and the paper is wound around the curl in the storage case 81. Therefore, it is wound up. When the leading edge of the paper reaches the feed roller pair 35, the transport roller pair 34 is accompanied by the paper transported by the feed roller pair 35 from the state in which the transport force is applied to the paper by the function of the one-way clutch 34c. It is switched to the state of driven rotation.

  Thereafter, when the sheet having the length of the winding amount determined by the winding amount determination unit 25 is conveyed downstream in the conveyance direction from the printing position by the head unit 73, the winding of the sheet is finished, The conveyance of the sheet from the sheet supply unit 40 toward the sheet winding unit 80 is stopped (step S112). That is, the conveyance amount detection unit 26 detects the conveyance amount of the paper detected based on the number of rotations of the conveyance roller pair 34 detected by the encoder 37 after the paper detection sensor 91 detects the leading edge of the paper. When the winding amount determined by the amount determination unit 25 and the length of the conveyance path in the overcoat unit 60 and the printing unit 70 are added, the conveyance control unit 27a finishes winding the sheet. Then, the conveyance of the sheet to the downstream side in the conveyance direction is stopped. At this time, the rear end portion of the first image, which is an image printed on the most upstream side in the conveyance direction, of the sheet having the winding amount is disposed at the printing position by the head unit 73.

  Then, the thermal head 61a of the overcoat unit 60 and the thermal heads 71a to 73a of the printing unit 70 are simultaneously moved from the retracted position to the printing position (step S113). Thereafter, the sheet is fed backward toward the upstream side in the transport direction by the transport force applied from the pair of paper feed rollers 31 and the pair of transport rollers 34 (step S114). Accordingly, at this time, the pair of paper feed rollers 31 and the pair of transport rollers 34 that have been driven to rotate are rotationally driven in the direction of transporting paper toward the upstream side in the transport direction, and the pair of feed rollers 35 The function of the clutch 35c causes the driven rotation. Further, the rotation shaft 43 of the paper supply unit 40 is rotationally driven in a direction to rewind the paper into the magazine case 41.

  Then, while the paper is being fed back toward the upstream side in the transport direction, for each image included in one order, printing corresponding to yellow is performed by the head unit 73, printing corresponding to magenta is performed by the head unit 72, and cyan printing is performed by the head unit 71. Printing corresponding to is sequentially performed. In this way, each image is printed in the order of yellow, magenta, and cyan, thereby completing the image (step S115). Thereafter, the head unit 61 continues to overcoat the surface of the paper on which the image is printed (step S116).

  In the present embodiment, when the required winding amount is shorter than the maximum winding amount, reverse printing to the upstream side in the sheet conveyance direction is started and image printing is started at the same time as one order. All of the images included in the image are printed intermittently so that a margin of a predetermined width is formed between the images. On the other hand, when the required winding amount is longer than the maximum winding amount, the reverse feeding to the upstream side in the sheet conveyance direction is started and at the same time, the printing of the image is started and one of the images included in one order The part is printed intermittently so that a margin part of a predetermined width is formed between the images. That is, as described above, the image is printed on the paper so that the image areas and the margins are alternately arranged. However, no image is printed in an area corresponding to the additional length for heat radiation near the leading edge of the paper. And in the printing part 70, when there exists an image area | region at the same timing in the position facing at least 2 of the three head parts 71-73, printing is simultaneously performed by those head parts. Further, the overcoat in the overcoat unit 60 is performed in parallel with the image printing in the printing unit 70. In this way, in the printing unit 70 and the overcoat unit 60, a plurality of printable sheets can be printed on the paper having the winding amount determined by the winding amount determination unit 25 or the paper having the maximum winding amount. Printing and overcoating are performed on the image.

  Thus, the paper on which printing and overcoat have been performed for a plurality of images is cut for each image by the cutting unit 50 in the procedure described in detail later. Then, after the leading edge of the final image printed closest to the leading edge of the sheet is cut, it is determined whether or not all the printing of images included in one order has been completed (step S117). If it is determined that printing of all the images included in one order has not been completed, the process returns to step S106 and the same processing as described above is repeated. On the other hand, when it is determined that printing of all the images included in one order has been completed, the process ends.

  Note that when it is determined in step S117 that printing of all images included in one order has not been completed, for example, the comparison unit 24 determines that the necessary winding amount is longer than the maximum winding amount, This is a case where the winding amount determination unit 25 determines the maximum winding amount as the final winding amount. That is, in this case, the remaining images that could not be printed on the sheet having the maximum winding amount among the images included in one order are continuously printed. In this way, the same processing as described above is repeated until printing of all the images included in one order is completed.

  Next, an operation when paper is cut in the printer 1 will be described with reference to FIGS. FIG. 8 is a flowchart showing an operation procedure for cutting a sheet on which an image has been printed. FIG. 9 is a diagram illustrating an operation until the trailing edge of the final image closest to the leading edge of the sheet is cut. FIG. 10 is a diagram illustrating an operation when the leading edge of the final image closest to the leading edge of the sheet is cut.

  8 to 10, it is assumed that 1 to n images (n is a positive integer) are printed from the leading edge of the sheet, and the position of the leading edge of the nth image is illustrated as An. The position of the end is illustrated as Bn. The position of the leading edge of the paper is shown as A0.

  In the above-described image printing operation procedure, after overcoating is performed on the surface of the paper on which the image has been printed, the conveying force applied from the paper feed roller pair 31 and the conveying roller pair 34 is continuously used as shown in FIG. As shown in (a), the paper is fed back toward the upstream side in the transport direction. Then, the rear end portion Bn of the image on the most upstream side in the transport direction of the paper (which coincides with the rear end portion of the paper having the length of the winding amount determined by the winding amount determination unit 25) is shown in FIG. As shown in b), the cutting position in the cutting unit 50 is reached (step S201). Note that the timing at which the rear end portion Bn of the image reaches the cutting position in the cutting unit 50 is detected based on the conveyance amount by the conveyance roller pair 34 detected by the conveyance amount detection unit 26.

  When the driving of the paper feed roller pair 31 is stopped, the reverse feeding of the paper upstream of the loop forming roller pair 37 is stopped, and the paper downstream of the transport roller 34 is fed from the transport roller pair 34. When the sheet is fed back by the transport force that is generated, a loop is formed between the transport roller pair 34 and the loop forming roller pair 37 as shown in FIG. 9C (step S202). At this time, the pressing member 39 arranged at the retracted position starts to move to the protruding position.

  After that, when the position detection sensor 92 detects that the pressing member 39 has reached the popping-out position and a loop having a predetermined length is formed, the pressing member 39 arranged at the popping-out position is returned to the retracted position, The paper is cut at the rear end Bn of the image (step S203). In addition, after the sheet is cut at the rear end Bn of the image in this way, the sheet on which the image upstream on the upstream side in the conveyance direction is not formed (determined by the winding amount determination unit 25). The sheet on the upstream side in the transport direction with respect to the trailing end of the sheet having the winding amount is rewound to the sheet supply unit 40.

  In this way, each time the sheet is cut at the trailing edge of the image, it is determined whether or not the image printed on the cut sheet is the second image from the leading edge of the sheet ( Step S204). If it is determined that the image is not the second image, the driving of the loop forming roller pair 37 is started as shown in FIG. 9D (step S211). Accordingly, the sheet upstream of the conveying roller pair 34 is reversely fed by the conveying force applied from the loop forming roller pair 37, and the sheet downstream of the conveying roller pair 34 is reversed by the conveying force applied from the conveying roller pair 34. Sent. At this time, the conveyance control unit 27a controls the conveyance speed of the sheet upstream of the conveyance roller pair 34 in the conveyance direction to be higher than the conveyance speed of the downstream sheet. The size of the loop between 34 and the loop forming roller pair 37 is reduced.

  When the rear end portion of the image upstream in the conveyance direction reaches the detection position by the image detection sensor 90, a detection signal indicating that the rear end portion of the image has been detected is transmitted from the image detection sensor 90 to the control device 20. Is done. Then, after the trailing edge of the image is detected by the image detection sensor 90, the conveyance amount detection unit 26 is upstream of the conveyance roller pair 34 based on the number of rotations of the loop forming roller pair 37 detected by the encoder 33b. The amount of paper transported to the side is detected. Then, as shown in FIG. 9E, when the leading end An of the image reaches the cutting position in the cutting unit 50 (step S212), the reverse feeding of the paper upstream of the loop forming roller pair 37 is stopped, The paper is cut at the front end An of the image (step S213). It should be noted that the cutting control unit 27 d detects that the leading end portion An of the image has reached the cutting position in the cutting unit 50 based on the amount of paper transported by the loop forming roller pair 37. In this manner, the paper cut at the front end portion An and the rear end portion Bn of the image is stored in the print box 96.

  Thereafter, as shown in FIG. 9F, the driving of the loop forming roller pair 37 is started again. Then, as shown in FIG. 9G, when the rear end portion Bn-1 of the (n-1) th image reaches the cutting position in the cutting unit 50 (step S214), the process returns to step S201 and is the same as described above. The process is repeated. Note that the above-described processing is repeated until it is determined in step S204 that the image is the second image.

  If it is determined in step S204 that the image is the second image, the rear end B1 of the final image reaches the cutting position in the cutting unit 50 as shown in FIG. 10A, and FIG. As shown in FIG. 5, the paper is in a state where cutting at the rear end B1 of the final image is completed. Thereafter, as shown in FIG. 10C, the driving of the loop forming roller pair 37 is started (step S205). When the leading end A0 of the sheet is sandwiched between the loop forming roller pair 37 (step S206), as shown in FIG. 10D, the roller 36e of the pressure roller pair 36 is moved to the pressure bonding position (step S206). S207).

  Thereafter, when the sheet is fed back to the upstream side in the transport direction by the pressure roller pair 36 (step S208), the leading end A1 of the final image reaches the cutting position in the cutting unit 50 as shown in FIG. (Step S209). As described above, the roller 36d of the pressure-bonding roller pair 36 is connected to the driving roller 37d of the loop forming roller pair 37 via the connecting belt 58, so that a conveying force can be applied to the paper.

  Then, as shown in FIG. 10 (f), the sheet is cut at the leading end A1 of the final image (step S210), and the process is terminated. The timing at which the leading edge A1 of the image reaches the cutting position in the cutting unit 50 is detected based on the conveyance amount by the pressure roller pair 36 detected by the conveyance amount detection unit 26.

  As described above, in the printer 1 according to the present embodiment, after the paper is transported in the direction from the paper supply unit 40 to the paper winding unit 80, the upstream side in the transport direction from the overcoat unit 60 and the printing unit 70. A plurality of images can be printed on a sheet that is fed back toward the upstream side in the transport direction by the transport force of the disposed transport roller pair 34. Therefore, it is possible to print an image in an area from the front end of the paper portion that is reversely fed after conveyance, and it is possible to suppress deterioration of the image due to load fluctuation during conveyance of the paper. Further, even when a plurality of images are printed on the paper, it is only necessary to reciprocate the paper, and it is only necessary to switch the paper transport direction in the transport mechanism 38 once. Can be reduced. As a result, when printing a plurality of images on paper, the processing capability of the printer 1 can be improved while preventing image deterioration due to paper waste and load fluctuations during paper transport.

  Further, the pressure roller pair 36 is provided at a distance shorter than the print length upstream of the loop forming roller pair 37 in the conveying direction, and the roller 36d of the pressure roller pair 36 is a driving roller of the loop forming roller pair 37. 37d and the connection belt 58 are connected. Therefore, when the sheet is cut at the leading edge of the final image, the sheet is not pinched by the loop forming roller pair 37, and the cutting position of the sheet cannot be controlled based on the sheet conveyance amount by the loop forming roller pair 37. However, the cutting position of the paper can be controlled based on the amount of paper transported by the pair of pressure rollers 36 that sandwich the paper. Therefore, it is possible to cut the paper at an appropriate position.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various design changes can be made as long as they are described in the claims. . For example, in the above-described embodiment, an image is formed on the sheet that is reversely fed toward the upstream side in the transport direction by the transport force of the transport roller pair 34 disposed on the upstream side in the transport direction with respect to the overcoat unit 60 and the print unit 70. Although it is printed, it is not limited to this. Therefore, an image may be printed on a sheet that is reversely fed toward the upstream side in the transport direction by the transport force of the transport roller pair disposed downstream of the overcoat unit 60 and the print unit 70 in the transport direction.

  In the above-described embodiment, the printer 1 in which a loop is formed between the conveyance roller pair 34 and the loop forming roller pair 37 has been described. In the printer in which no loop is formed, it is not necessary to provide the loop forming roller pair 37. Accordingly, in this case, the pressure roller pair 36 (second transport roller pair) is provided at a distance shorter than the print length upstream of the transport roller pair 34 (first transport roller pair) in the transport direction. The roller 36d of the pressure roller pair 36 may be connected to the drive roller 34d of the transport roller pair 34 via a connecting belt.

  In the above-described embodiment, the rotation shaft 37f of the driving roller 37d of the loop forming roller pair 37 and the pressure roller pair 36 are set so that the conveying speeds of the loop forming roller pair 37 and the pressing roller pair 36 are the same. A connecting belt 58 is stretched between the rotating shaft 36f of the roller 36d, and a connecting mechanism for connecting the loop forming roller pair 37 and the pressure roller pair 36 so that the conveying speed is the same. The configuration of can be changed. Therefore, the connecting mechanism may be, for example, a cam mechanism that connects the loop forming roller pair 37 and the pressure roller pair 36.

  In the above-described embodiment, the printing unit 70 has a plurality of head units 71 to 73, and a color image is printed on the paper. However, the printing unit has only one head unit. A single color image may be printed on the paper.

  In the above-described embodiment, in the thermal sublimation printer 1, an image is printed by the three head portions 71 to 73 that come into contact with the recording medium, but any printer that can record an image is used. The configuration of the image recording unit is not limited to this. Therefore, it may be a thermal printer (including a thermal transfer system and a thermal recording system) having a head that comes into contact with a recording medium, and has, for example, an inkjet head, a FOCRT (Fiber Optic Cathode-Ray-Tube), a laser light source, etc. The printer may be capable of recording an image without contacting the recording medium. Further, the image recording unit does not necessarily have a plurality of image recording heads, and may have only one image recording head capable of recording an image. Accordingly, for example, it has three inkjet heads each having nozzles capable of ejecting yellow, magenta, and cyan inks, and these heads record images while reciprocating in the direction intersecting the recording medium conveyance direction. It may be a printer or has one inkjet head having nozzles capable of discharging yellow, magenta, and cyan inks, and the head reciprocates in a direction crossing the recording medium conveyance direction. It may be a printer that records.

1 is an external perspective view of a printer according to an embodiment of the present invention. It is a figure which shows schematic structure of the printer part of the printer of FIG. It is a figure which shows the structure of the cutting position vicinity in the cutting mechanism contained in the printing part of FIG. It is a figure showing operation | movement of the conveyance roller pair and feed roller pair of the printer of FIG. It is a block diagram about the principal part of the printer of FIG. 1, and the control apparatus to which these were connected. It is a figure which shows a mode when the some image contained in 1 order is printed by the front-end | tip part vicinity of a paper. 2 is a flowchart illustrating an operation procedure when an image is printed by the printer of FIG. 1. 3 is a flowchart illustrating an operation procedure when cutting of a sheet is performed in the printer of FIG. 1. FIG. 10 is a diagram illustrating an operation until a rear end portion of a final image closest to a front end portion of a sheet is cut. FIG. 10 is a diagram illustrating an operation when the leading edge of the final image closest to the leading edge of the sheet is cut.

Explanation of symbols

1 Thermal printer (printer)
DESCRIPTION OF SYMBOLS 10 Operation part 20 Control apparatus 21 Maximum winding amount memory | storage part 22 Print information storage part 23 Required winding amount calculation part 24 Comparison part 25 Winding amount determination part 26 Conveyance amount detection part (conveyance amount detection means)
27a Transport control unit (transport control means)
27b Print control unit (image recording control means)
27c Cutting control part (cutting control means)
27d Curl removal control unit 30 Print unit 33a Encoder 33b Encoder (rotational speed detection means)
34 Transport roller pair (first transport roller pair)
36 Pressure roller pair (second transport roller pair)
37 Loop forming roller pair (third transport roller pair)
38 Transport mechanism 40 Paper supply unit (supply unit)
50 Cutting part (cutting mechanism)
58 Connecting belt 60 Overcoat part 61a Thermal head 70 Printing part (image recording part)
71a-73a Thermal head 80 Paper winding part

Claims (3)

An image recording unit capable of recording an image on a recording medium;
A supply unit storing a long recording medium;
A cutting mechanism capable of cutting the recording medium;
By sandwiching the recording medium on the downstream side of the cutting mechanism, the first direction from the supply unit to the image recording unit while the recording medium faces the image recording unit is opposite to the first direction. A first conveying roller pair capable of conveying in a second direction which is a direction;
A second conveying roller pair capable of conveying the recording medium in the second direction by sandwiching the recording medium upstream of the cutting mechanism;
A rotational speed detection means capable of detecting the rotational speed of the first conveying roller pair;
A conveyance amount detection means for detecting a conveyance amount of the recording medium based on the rotation number detected by the rotation number detection means;
A coupling mechanism that couples the first conveyance roller pair and the second conveyance roller pair so that the respective conveyance speeds are the same;
The first medium is transported in the second direction after the recording medium is transported in the first direction until the leading end of the recording medium reaches a position away from the image recording unit in the first direction. A conveyance control means for controlling a pair of conveyance rollers;
Image recording control means for controlling the image recording unit so that a plurality of images are recorded by the image recording unit on a recording medium conveyed in the second direction by the first conveying roller pair;
Cutting control means for controlling the cutting mechanism so that the recording medium conveyed in the second direction is cut at a timing based on the conveyance amount detected by the conveyance amount detection means,
The cutting control means includes
When the recording medium is cut from the leading edge of the recording medium at a position longer than the distance between the first conveying roller pair and the cutting position in the cutting mechanism, the recording medium is detected by the conveyance amount detecting means. Cutting the recording medium at a timing based on the conveyance amount of the recording medium by the first conveyance roller pair;
When the recording medium is cut from the leading edge of the recording medium at a position shorter than the distance between the first conveying roller pair and the cutting position in the cutting mechanism, the recording medium is detected by the conveyance amount detecting means. A printer that cuts a recording medium at a timing based on a conveyance amount of the recording medium by the second conveyance roller pair. An image recording unit capable of recording an image on a recording medium;
A supply unit storing a long recording medium;
A cutting mechanism capable of cutting the recording medium;
A first transport capable of transporting a recording medium in a first direction from the supply unit toward the image recording unit and a second direction opposite to the first direction while facing the image recording unit With Laura pair,
A second conveying roller pair capable of conveying the recording medium in the second direction by sandwiching the recording medium upstream of the cutting mechanism;
A third conveying roller pair capable of conveying the recording medium in the second direction by sandwiching the recording medium between the cutting mechanism and the first conveying roller pair;
A rotational speed detecting means capable of detecting the rotational speed of the third conveying roller pair;
A conveyance amount detection means for detecting a conveyance amount of the recording medium based on the rotation number detected by the rotation number detection means;
A coupling mechanism for coupling the second conveyance roller pair and the third conveyance roller pair so that the respective conveyance speeds are the same;
The first medium is transported in the second direction after the recording medium is transported in the first direction until the leading end of the recording medium reaches a position away from the image recording unit in the first direction. A conveyance control means for controlling a pair of conveyance rollers;
Image recording control means for controlling the image recording unit so that a plurality of images are recorded by the image recording unit on a recording medium conveyed in the second direction by the first conveying roller pair;
Cutting control means for controlling the cutting mechanism so that the recording medium conveyed in the second direction is cut at a timing based on the conveyance amount detected by the conveyance amount detection means,
The cutting control means includes
When the recording medium is cut from the leading edge of the recording medium at a position longer than the distance between the third conveying roller pair and the cutting position of the cutting mechanism, the recording medium is detected by the conveyance amount detecting means. Cutting the recording medium at a timing based on the conveyance amount of the recording medium by the third conveyance roller pair;
When the recording medium is cut from the leading edge of the recording medium at a position shorter than the distance between the third conveying roller pair and the cutting position in the cutting mechanism, the recording medium is detected by the conveyance amount detecting means. A printer that cuts a recording medium at a timing based on a conveyance amount of the recording medium by the second conveyance roller pair.   The first conveying roller pair is capable of conveying a recording medium in the second direction by applying a conveying force to the recording medium between the supply unit and the image recording unit. The printer according to claim 1 or 2.

Images