JP2008155417A - Printer - Google Patents

Abstract

Provided is a printer capable of eliminating slack of roll paper and transporting the roll paper at a predetermined speed so as to eliminate print pitch disturbances such as print shrinkage and print elongation.
SOLUTION: Support rollers 10 and 11 which are rotatably provided in a hopper 9 and rotatably support a roll paper 3, and support rollers 10 in the same direction as the rotation direction of the roll paper 3 pulled out from the hopper 9. 11 is rotated so that the roll paper 3 stored and held in the hopper 9 is back-fed to the printer P, and the back-feed mechanism 34 is driven prior to the start of the image forming operation by the print transport mechanism. The source (cutter motor M2) is driven and controlled so that the roll paper 3 is back-fed at a length equal to or longer than the expected length of slack that occurs on the roll paper 3 upon completion of the image forming operation.
[Selection] Figure 5

Description

  The present invention relates to a printer that pulls out and prints roll paper stored in a hopper.

  2. Description of the Related Art Conventionally, in a printer that pulls out and prints roll paper stored in a hopper, a rotatable roller is disposed on the bottom surface of the hopper that stores the roll paper, and the roll paper stored by this roller is supported by the roller. There is. The roller rotates in the direction opposite to the rotation direction of the roll paper when the roll paper rotates by pulling out the paper, thereby reducing the frictional resistance between the roll paper and the paper drawing operation.

JP-A-7-76443

  In the printer having the above configuration, the roll paper may continue to rotate for a while due to the inertia weight even after the roll paper is pulled out and printing is completed. As a result, the roll paper is pulled out more than necessary, and slack occurs.

  When the platen roller is rotated for receipt issuance and the paper is pulled into the printing mechanism and transported, the paper is slackened immediately after the start of transport, so no tension is generated on the platen roller. When the pressure gradually decreases and the slack disappears, a large tension is generated on the platen roller in the direction opposite to the sheet conveyance direction. Thereafter, the roll paper starts to rotate and is conveyed while being pulled out, so that the tension decreases.

  This tension affects the sheet conveyance speed. While the paper is slack, the paper is transported at the specified transport speed, but at the moment when the slack disappears, the transport speed rapidly decreases due to a large tension, and then the tension decreases and the transport speed increases. I will do it. Therefore, at the moment when the slack disappears, a print shrinkage in which the line interval of the print becomes smaller due to a rapid decrease in the conveyance speed occurs, and thereafter, a print elongation in which the line interval becomes larger due to the increase in the conveyance speed occurs.

  In Patent Document 1, in order to remove the slack of the roll paper that is generated when the roll paper is introduced into the hopper with the leading end of the roll paper loosened and loosened, the roller is rotated in the direction opposite to the roll paper drawing rotation direction. It has been proposed that the roll paper is pulled out and rotated in the rotation direction. However, in the invention described in Patent Document 1, it is not possible to remove the slack caused by the rotation of the roll paper due to the inertial weight described above, and therefore it is possible to eliminate printing pitch disturbances such as printing shrinkage and printing elongation. I can't.

  SUMMARY OF THE INVENTION An object of the present invention is to eliminate printing pitch disturbances such as printing shrinkage and printing elongation caused by roll paper slack that occurs after a printing operation.

  The printer according to the present invention includes a hopper that stores and holds roll paper wound in a roll shape, a guide path that guides the roll paper drawn from the hopper to a predetermined path, and a roll paper that is drawn to the guide path. A print transport mechanism that forms an image on the roll paper by transporting and printing with the print head, and an axis oriented in the same direction as the axial direction of the roll paper stored and held in the hopper in the hopper A support roller that is rotatably provided and supports the roll paper, and the support roller is rotated in the same direction as the rotation direction of the roll paper drawn from the hopper, and the roll paper stored and held in the hopper is back-fed. Prior to the start of the image forming operation by the back feed mechanism and the print transport mechanism, the drive source of the back feed mechanism is driven and controlled, And means for forecasting a length longer than the slack is back-fed the roll paper that occurs in the roll paper due to the completion of the forming operation, a.

  According to the present invention, the slack of the roll paper can be removed by backfeeding the roll paper prior to the start of the image forming operation. Accordingly, the roll paper can be conveyed at a constant speed, and printing such as print shrinkage and print elongation can be performed. Pitch disturbance can be eliminated.

  An embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present embodiment is an application example to a receipt printer built in, for example, an ECR (electronic cash register) or a POS terminal (sales point information management device). The embodiments described below are preferred examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise described, the present invention is not limited to these embodiments.

  FIG. 1 is a basic configuration diagram of the printer P of the present embodiment. First, the basic configuration and basic operation of the printer P will be described with reference to FIG. The printer P includes a printer main body 1 to which various parts are attached, and an upper unit 2 is attached to the printer main body 1 so as to be freely opened and closed.

  As shown in FIG. 1, the printer P is formed with a guide path 5 for pulling out the roll paper 3 and guiding it to the paper discharge port 4 provided on the front surface of the printer P. A roll paper storage holder 6 for storing and holding the roll paper 3 is provided in the printer main body 1 along the guide path 5, and the roll paper 3 is drawn out from the roll paper storage holder 6 to be printed. A print transport unit 7 and a paper cutting unit 8 for cutting the roll paper 3 are provided.

  The roll paper storage holder 6 is provided with a hopper 9 for storing the roll paper 3 and support rollers 10 and 11 for rotatably supporting the stored roll paper 3. The support rollers 10 and 11 are formed on the bottom surface 9a of the hopper 9 with a predetermined interval and are formed in the recesses of the grooves 12 and 13 having a semicircular arc cross-sectional shape. The roll paper 3 is rotatably supported around an axis oriented in the same direction as the axial direction.

  The print transport unit 7 includes a thermal head 14 and a platen roller 15 for printing on the roll paper 3 drawn from the hopper 9. As shown in FIG. 1, the thermal head 14 is disposed so as to be brought into contact with the platen roller 15 through the guide path 5 with a predetermined pressure. The thermal head 14 includes a plurality of heat generating elements (not shown), and the plurality of heat generating elements are selectively energized to generate heat and come into contact with the roll paper 3 which is thermal paper. The platen roller 15 also has a function for pulling out and transporting the roll paper 3.

  The paper cutting unit 8 is provided with a fixed blade 16 and a movable blade 17 for cutting the roll paper 3. As shown in FIG. 1, the fixed blade 16 and the movable blade 17 are provided at positions where the roll paper 3 is sandwiched therebetween and can be cut, and a rotary cutter that cuts the roll paper 3 by the rotation of the movable blade 17. Constitute.

  Next, the basic operation of the printer P will be described. As shown in FIG. 1, when the platen roller 15 is rotationally driven and the roll paper 3 in contact with the platen roller 15 is fed in the transport direction along with the rotation of the platen roller 15, the roll paper 3 is pulled out from the hopper 9 and the platen roller 15. It is conveyed to the side.

  When the roll paper 3 is conveyed to the platen roller 15, printing is performed on the roll paper 3 by the thermal head 14. The platen roller 15 is intermittently driven to feed the roll paper 3 in the transport direction every time printing is performed on the roll paper 3.

  The roll paper 3 on which printing has been performed by the thermal head 14 is subsequently conveyed toward the paper discharge direction by the rotational drive of the platen roller 15. When the roll paper 3 passes the position of the paper cutting unit 8, the rotation of the platen roller 15 is stopped. Then, the movable blade 17 provided in the paper cutting unit 8 is driven to rotate, and the roll paper 3 sandwiched between the fixed blade 16 is cut. The roll paper 3 including the cut print portion is discharged as, for example, a receipt from a paper discharge port 4 provided at the downstream end of the guide path 5.

  In the printer P of the present embodiment, in addition to the above-described configuration, a platen roller driving mechanism 18 (see FIG. 2) for rotating the platen roller 15 and a movable blade driving mechanism 23 (for moving the movable blade 17). 4 and FIG. 5) and a back feed mechanism 34 (FIG. 5) for back feeding the roll paper 3 stored and held in the hopper 9 by rotating the support rollers 10 and 11 in the same direction as the rotation direction of the roll paper 3. 6). First, the configuration of each of the drive mechanisms 18, 23, and 34 will be described first.

  First, the configuration of the platen roller drive mechanism 18 will be described.

  FIG. 2 is a perspective view showing the printer P with the upper unit 2 opened. As shown in FIG. 2, the platen roller driving mechanism 18 is disposed outside the left side surface of the printer main body 1, and is a mechanism that rotationally drives the platen roller 15 to transport the roll paper 3.

  FIG. 3 is a configuration diagram showing the configuration of the platen roller driving mechanism 18. The platen roller drive mechanism 18 includes a feed motor M1, a feed motor gear 19 mounted on the rotation shaft 19a of the feed motor M1, an idle gear 20 mounted on the rotation shaft 20a, and an idle mounted on the rotation shaft 21a. A gear 21 and a platen gear 22 mounted on the rotation shaft of the platen roller 15 are provided. The gears are meshed in the order of the feed motor gear 19, idle gears 20 and 21, and platen gear 22.

  When the feed motor M1 is rotationally driven, the rotation of the feed motor M1 is transmitted in the order of the feed motor gear 19, the idle gears 20 and 21, and the platen gear 22, and the platen roller 15 is rotationally driven.

  Next, the configuration, function, and operation of the movable blade drive mechanism 23 will be described.

  FIG. 4 is a right side view of the printer P of the present embodiment. The movable blade drive mechanism 23 is mainly disposed outside the right side surface of the printer main body 1 and is a mechanism for moving the movable blade 17 in order to cut the roll paper 3. As shown in FIG. 4, the movable blade drive mechanism 23 uses a cutter motor M2 (not shown) in which a cutter motor gear 25 (shown by a one-dot chain line) is fixedly mounted on a rotary shaft 24 (shown by a one-dot chain line) as a drive source. A cutter gear 27 (shown by a one-dot chain line) which is engaged with the cutter motor gear 25 and fixedly mounted on the rotating shaft 26 by receiving a driving force from the cutter motor M2, and a plate fixedly mounted on the rotating shaft 26 When the cutter arm 29 slidably connected to the plate cam 28 is driven via the cam 28 as a power transmission medium, the movable blade 17 is driven to rotate.

  The cutter arm 29 is connected to the plate cam 28 as a follower so as to constitute a cam mechanism having the plate cam 28 as a driving node, and is slidably driven around a support shaft 30. A connecting hole 31 is formed in the moving tip portion, and a connecting pin 32 provided on the side surface of the movable blade 17 is fitted. The movable blade 17 is pivotally supported by a support shaft 33 as shown in FIG. Therefore, when the cutter arm 29 is slidably driven around the support shaft 30, the connection pin 32 fitted in the connection hole 31 of the cutter arm 29 is driven, and the movable blade 17 is centered on the support shaft 33. Rotate.

  FIG. 5A is a configuration diagram showing the movable blade driving mechanism 23 in a state where the fixed blade 16 and the movable blade 17 are not engaged with each other. FIG. 5B is a configuration diagram showing the movable blade driving mechanism 23 in a state where the fixed blade 16 and the movable blade 17 are engaged with each other.

  As shown in FIG. 5A, in a state where the fixed blade 16 and the movable blade 17 are not engaged with each other, when the cutter motor is rotated in the clockwise direction (R direction) in FIG. The rotation is transmitted from the cutter motor gear 25 to the cutter gear 27, and the plate cam 28 rotates counterclockwise (L direction).

  The cutter arm 29 slides in accordance with the rotation of the plate cam 28 and rotates counterclockwise (L direction) from the predetermined position about the support shaft 30 by a predetermined amount. As a result, when the connecting pin 32 fitted in the connecting hole 31 of the cutter arm 29 is driven, the movable blade 17 rotates counterclockwise (L direction) about the support shaft 33 as shown in FIG. As shown in b), the fixed blade 16 and the movable blade 17 are engaged with each other, and the roll paper 3 sandwiched therebetween is cut.

  Next, the configuration, function, and operation of the back feed mechanism 34 will be described.

  FIG. 6 is a perspective view showing a back feed mechanism. As shown in FIG. 6, the back feed mechanism 34 uses the cutter motor M2 as a drive source, and transmits the driving force of the cutter motor M2 through the idle gears 35 and 36 and pulleys 37, 38, and 39, 11, and the support rollers 10 and 11 are rotated in the same direction as the rotation direction of the roll paper 3 drawn out from the hopper 9 to back feed the roll paper 3 stored and held in the hopper 9 (FIG. 4). reference).

  The idle gear 35 is rotatably mounted on the rotating shaft 40 and engaged with the cutter gear 27, and the idle gear 36 is fixedly mounted on the rotating shaft 41 and engaged with the idle gear 35. The pulley 37 is configured by winding a pulley belt 45 between a pulley gear 42 fixedly mounted on the rotating shaft 41 and a pulley gear 44 fixedly mounted on the rotating shaft 43.

  The pulley 38 is configured by winding a pulley belt 48 between a pulley gear 46 fixedly mounted on the rotating shaft 43 and a pulley gear 47 with a one-way clutch mounted on one end of the rotating shaft 52 of the roller 10. . The pulley 39 is configured by winding a pulley belt 51 between a pulley gear 49 fixedly mounted on the rotating shaft 43 and a pulley gear 50 with a one-way clutch mounted on one end of the rotating shaft 54 of the roller 11. Yes.

  Further, as shown in FIG. 6, the support roller 10 includes a rotation shaft 52 and a substantially cylindrical body portion 53. Similarly, the support roller 11 includes a rotation shaft 54 and a substantially cylindrical body portion. 55.

  As described above, the back feed mechanism 34 is provided with pulley gears 47 and 50 with one-way clutches at one end portions of the support rollers 10 and 11, respectively. The one-way clutch has a function of transmitting power only in one direction of rotation. It is what you have.

  Therefore, as shown in FIG. 6, for example, the cutter motor M2 rotates in the R direction, and the rotation of the cutter motor M2 is transmitted in the order of the cutter gear 27, the idle gears 35 and 36, and the pulley 37, and the pulleys 38 and 39 Is driven and the pulley gears 47 and 50 with one-way clutch are driven to rotate in the L direction, respectively, the rotation shafts 52 and 54 of the support rollers 10 and 11 are fixed to the bearing portions of the pulley gears 47 and 50 with one-way clutch, respectively. As a result, the support rollers 10 and 11 are rotationally driven in the L direction.

  Therefore, in this case, the back feed mechanism 34 drives the pulleys 38 and 39 to rotate the support rollers 10 and 11 in the L direction, thereby rotating the roll paper 3 in the R direction and backing the roll paper 3. Operates to feed.

  Further, when the support rollers 10 and 11 rotate in the R direction, the rotation shafts 52 and 54 of the support rollers 10 and 11 and the bearing portions of the pulley gears 47 and 50 with one-way clutch are not fixed, respectively. 11 freely rotates in the R direction without receiving resistance from the pulley gears 47 and 50 with one-way clutches.

  Therefore, when the roll paper 3 in the hopper 9 is pulled out and the roll paper 3 rotates in the L direction, the support rollers 10 and 11 receive a load from the pulley gears 47 and 50 (pulleys 38 and 39) with one-way clutches. Without being rotated freely in the R direction, the frictional resistance of the portion in contact with the roll paper 3 can be reduced, and the roll paper 3 can be pulled out smoothly.

  FIG. 7 is a block diagram showing the electrical connection between the printer P and the host device. The host device of the printer P of this embodiment is a cash register or the like, and causes the printer P to execute receipt printing or the like. The host device includes a CPU (Central Processing Unit) 101, a storage unit 102, a keyboard 103, and a keyboard controller 104. The CPU 101 executes various arithmetic processes and centrally controls each part of the host device. The storage unit 102 includes a ROM, a RAM, and the like.

  When a receipt issuance instruction is received via the keyboard controller 104 by an input from the keyboard 103, the CPU 101 executes a program stored in the ROM, and prints data on the receipt as print data including character codes. Control is performed so that the print data temporarily stored in the RAM and temporarily stored in the RAM via the system bus and the printer controller 105 is transmitted to the printer P.

  FIG. 8 is a block diagram showing the electrical connection of each unit included in the printer P. The printer P includes a control unit 60. The control unit 60 includes a CPU 61 that executes various arithmetic processes, a ROM (Read Only Memory) 62 that stores fixed data such as a computer program in advance, and a RAM (Random Access) that functions as a work area that stores various data in a rewritable manner. (Memory) 63, an I / O port 64 comprising an input port for fetching information to the CPU 61 side, an output port for sending information from the CPU 61 side to the outside (each part of the printer), and reception of print data from the host device. A communication interface 65 for exchanging data is connected and configured via a bus line 68. The RAM 63 is backed up by a battery and includes a print buffer and a character generator.

  As shown in FIG. 8, the CPU 61 includes a motor 66 (feed motor M1 and cutter motor M2), a thermal head 14, various sensors (a paper sensor for detecting the out of paper, a cover for detecting the opening and closing of the cover) of each part of the printer. An open / close sensor 67) and the like are connected via a bus line 68, and the CPU 61 centrally controls these units.

  Next, the operation of the back feed mechanism 34 shown in FIG. 6 will be described in detail below.

  FIG. 9 is a flowchart for explaining the operation of the back feed mechanism 34. As shown in FIG. 9, first, in step S101, when the CPU 61 of the printer P obtains print data from the CPU 101 of the host apparatus shown in FIG. 8 via the printer controller 105, the feed motor M1 is rotated to control the platen. Control for driving the roller driving mechanism 18 to rotate the platen roller 15 is executed. As a result, the roll paper 3 stored in the hopper 9 starts to be conveyed to the print conveyance unit 7 side.

  Subsequently, in step S102, the CPU 61 searches for the corresponding character pattern from the character patterns stored in the character generator in accordance with the print data received from the host device, and expands the searched character pattern as print data in the print buffer.

  Then, the CPU 61 controls the thermal head 14 to execute printing on the roll paper 3 line by line according to the print data while controlling the rotation of the platen roller 15 and intermittently transporting the roll paper 3 at a constant speed. To do. At this time, since the roll paper 3 is not slack and no tension is generated based on this, the roll paper 3 is intermittently conveyed at a constant speed and printed by the thermal head 14. Therefore, stable printing is performed on the roll paper 3 at a predetermined line interval.

  Subsequently, in step S103, when the CPU 61 recognizes that the printing on the roll paper 3 has been completed, the drive of the feed motor M1 is stopped after the lapse of a predetermined time, the rotation of the platen roller 15 is ended, and the paper is conveyed. Control to end. However, the roll paper 3 may continue to rotate due to the inertia weight of the roll paper 3 even after the rotation of the platen roller 15 is stopped and the conveyance of the paper is finished. appear.

  As described above, this slack causes the platen roller 15 to generate a large tension in the direction opposite to the direction in which the roll paper 3 is conveyed. This prevents stable conveyance of the roll paper 3 and reduces the line interval when the next receipt is issued. This is not preferable because it causes printing pitch disturbances such as printing shrinkage and printing elongation that increases line spacing.

  Subsequently, in step S <b> 104, the CPU 61 controls to rotate the cutter motor M <b> 2 in order to cut the roll paper 3. When the cutter motor M2 is rotationally driven in the R direction by the CPU 61, the movable blade 17 constituting the rotary cutter is driven. That is, the rotational driving force in the R direction of the cutter motor M2 is transmitted in order from the cutter motor gear 25 to the cutter gear 27 and the plate cam 28, and the plate cam 28 is rotationally driven. As a result, the cutter arm 29 swings about the support shaft 30, and the driving force is transmitted to the movable blade 17 via the connecting pin 32 fitted in the connecting hole 31 of the cutter arm 29. Then, the movable blade 17 is rotationally driven in the L direction around the support shaft 33 and meshed with the fixed blade 16. As a result, the roll paper 3 sandwiched between the movable blade 17 and the fixed blade 16 is cut. The cut roll paper 3 is discharged as a receipt from a paper discharge port 4 shown in FIG. 1 (see FIGS. 5A and 5B).

  By the way, when the roll paper 3 is cut, a blank portion where no printing is performed occurs between the printing position by the thermal head 14 and the cutting position of the roll paper 3. In the printer P of the present embodiment, the CPU 61 controls the thermal head 14 so as to print a logo to be printed on the leading end portion of a receipt to be issued next time, in order to prevent the margin portion from being generated. I have to.

  Accordingly, the roll paper 3 is cut between the print portion of the print data and the print portion of the logo. Therefore, the CPU 61 controls the rotation of the platen roller 15 so that the boundary portion between the print portion of the print data of the roll paper 3 and the print portion of the logo is positioned at the cutting position of the roll paper 3 (the engagement between the movable blade 17 and the fixed blade 16). Then, the platen roller 15 is controlled to stop rotating.

  On the other hand, the back feed mechanism 34 shown in FIG. 6 is driven in conjunction with the start of rotation of the cutter motor M2 for cutting the roll paper 3 described above. Specifically, when the cutter motor gear 25 of the cutter motor M2 is rotationally driven in the R direction under the control of the CPU 61, the cutter gear 27 rotates in the L direction in conjunction with this, and the idle gear 35 continues to rotate in the R direction. The idle gear 36 and the pulleys 37, 38, 39 rotate in the L direction.

  As a result, the pulley gears 47 and 50 with one-way clutch are driven to rotate in the L direction, and this rotation is transmitted to the support rollers 10 and 11 so that the support rollers 10 and 11 are driven to rotate in the L direction. When the support rollers 10 and 11 are driven to rotate in the L direction, the roll paper 3 rotates in the R direction and the roll paper 3 is back-fed, so that the slack of the roll paper 3 is removed.

  Therefore, since the slack is eliminated at the next receipt issuance, the tension in the direction opposite to the conveyance direction (tension caused by the slack) does not occur on the platen roller 15, and the roll paper 3 is intermittent at a constant speed. And is printed by the thermal head 14. Therefore, stable printing is performed on the roll paper 3 at a predetermined line interval. For this reason, it is possible to prevent printing pitch disturbances such as printing shrinkage and printing elongation.

  The operation of the back feed mechanism 34 described above is based on the assumption that no slack has occurred in the roll paper 3 when the roll paper 3 starts to be transported. Further, the back feed mechanism 34 is configured to rewind the roll paper 3 with a length equal to or longer than a predicted length of slack that occurs in the roll paper 3.

  By the way, the slack that occurs is not always constant, and varies depending on the usage status of the printer P and the roll paper 3. Therefore, when the slack of the roll paper 3 is small, the support rollers 10 and 11 may continue to rotate the roll paper 3 in the rewinding direction even after the slack is removed. However, in that case, the roll paper 3 and the support rollers 10 and 11 slide against each other, so there is no fear that the roll paper 3 receives a tensile force from the platen roller 15 side and is torn.

  Further, as described above, the control for backfeeding the roll paper 3 may be combined with the rotational drive control of the cutter motor M2 for cutting the roll paper 3, or may be executed separately. . When this back feed control is executed separately from the control of the cutter motor M2 in the cutting operation of the roll paper 3, the next printing is performed immediately after the conveyance of the roll paper 3 is finished and the slack occurs in step 103. It can be executed at a predetermined timing before the start of the image forming operation.

  Further, since the back feed mechanism 34 of the present embodiment uses the cutter motor M2 for cutting the roll paper 3 in the rewinding operation of the roll paper 3, it is necessary to add a motor as a new drive source to the printer P. There is no. The motor used for the back feed mechanism 34 is not limited to the cutter motor M2 of this embodiment, and another motor may be used.

  Further, the back feed mechanism 34 of the present embodiment has a configuration in which the support rollers 10 and 11 are driven to rotate by using the pulleys 38 and 39. However, the support roller 10 or the roller 39 by using either the pulley 38 or the pulley 39. Any one of 11 may be driven to rotate. Further, either one of the pulleys 38 and 39 is omitted, and a new pulley is provided between the support roller 10 and the support roller 11 instead, and the rotational force transmitted to either the support roller 10 or the support roller 11 is provided. It is good also as a structure which transmits to the other support roller through the pulley provided newly.

  Further, in the printer P of the present embodiment, the number of support rollers is two, but the number is not limited to this, and the number, configuration, arrangement position, and arrangement method of the support rollers may be appropriately changed according to the purpose. The back feed mechanism of this embodiment can be modified and applied without departing from the spirit of the invention. For example, in a printer having a plurality of rollers, one of the support rollers may be driven to rotate, or some of the specified support rollers may be driven to rotate.

1 is a basic configuration diagram of a printer of an embodiment. It is a perspective view which shows the printer of the state which opened the upper unit. It is a block diagram which shows the structure of a platen roller drive mechanism. FIG. 2 is a right side view of the printer according to the embodiment. (A) is a block diagram showing a movable blade drive mechanism in a state where the fixed blade and the movable blade are not engaged with each other. (B) is the block diagram which showed the movable blade drive mechanism of the state which the fixed blade and the movable blade meshed | engaged. It is a perspective view which shows a back feed mechanism. It is a block diagram which shows the electrical connection of a printer and a high-order apparatus. FIG. 3 is a block diagram illustrating electrical connection of each unit included in the printer. It is a flowchart for demonstrating operation | movement of a back feed mechanism.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Roll paper, 5 ... Guide path, 7 ... Print conveyance part, 9 ... Hopper, 10, 11 ... Support roller, 14 ... Thermal head (print head), 17 ... Movable blade, 34 ... Back feed mechanism, M2 ... Cutter Motor, L: the same rotation direction as the roll paper drawn from the hopper, P: printer

Claims (3)

A hopper for storing and holding roll paper wound in a roll;
A guide route for guiding the roll paper drawn from the hopper to a predetermined route;
A print transport mechanism that forms an image on the roll paper by transporting the roll paper drawn to the guide path and printing with the print head;
A support roller which is rotatably provided around an axis oriented in the same direction as the axial direction of the roll paper stored and held in the hopper and supports the roll paper;
A back feed mechanism that rotates the support roller in the same direction as the rotation direction of the roll paper drawn from the hopper, and back-feeds the roll paper stored and held in the hopper;
Prior to the start of the image forming operation by the print conveying mechanism, the drive source of the back feed mechanism is driven and controlled, and the roll paper has a length that is equal to or longer than the expected length of slack that occurs on the roll paper when the image forming operation ends. Means for backfeeding,
Printer with.     The printer according to claim 1, wherein the roll paper is supported in the hopper only by the pair of support rollers. A cutter that is driven by a drive source that is also used as a drive source of the backfeed mechanism and cuts roll paper after image formation;
3. The printer according to claim 1, wherein rotation of a motor that is the driving source is used for back feeding of roll paper by the back feeding mechanism and cutting operation of the cutter.

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