JP4410589B2 - Printer - Google Patents

Description

  The present invention relates to a printer, and more particularly to a printer in which the distance between a print head and a platen can be adjusted in accordance with the thickness of a recording sheet.

2. Description of the Related Art Conventionally, there is a type in which a print head is moved forward and pressed against a recording sheet, and the print head is moved backward with reference to the position to adjust an interval between the print head and the platen. For example, there is one configured to detect a pressing position of a print head against a recording sheet by stepping out of a pulse motor (Patent Document 1). Also, the driving force of the motor is transmitted to the adjusting mechanism via two disks that are connected together by a spring force so that the encoder can be operated when one of the disks stops when the print head is pressed against the recording paper. There is one that detects the stop of one of the discs and detects the pressing position of the print head against the recording paper (Patent Document 2). On the other hand, the applicant stores the position when the print head presses the recording paper on the platen as means for adjusting the distance between the print head and the platen by moving the print head back and forth with respect to the platen. In addition, a printer in which the print head is retracted so as to have an appropriate interval from the position is disclosed (Patent Document 3).
JP-A-1-176578, Japanese Patent Laid-Open No. 3-118176 Japanese Patent No. 2852336

  In the first example of the prior art (Patent Document 1), there is a problem that vibration and noise are generated with the step-out of the pulse motor. Further, in the second example of the above prior art (Patent Document 2), a highly accurate encoder is required, and it is necessary to detect a stop of the disk by setting a predetermined determination criterion, so that the control becomes complicated and the cost is high. There were problems such as becoming. In the third example (Patent Document 3), the distance between the platen and the print head can be kept constant corresponding to the change in the paper thickness, but the paper is different in paper quality such as copy paper or card. However, since printing is performed at the same interval without considering the paper quality, there is a problem that printing cannot be performed in the best state for printing on recording paper of different paper quality. In each of the above conventional techniques, since the detection of the paper surface position is performed only at one place, there is a problem that the reliability is low and the change in the paper quality cannot be sufficiently dealt with.

According to the present invention, the print head is pressed against the recording paper inserted between the two by bringing the print head close to the platen, and the print head is separated from the platen by a predetermined amount with respect to the position, and the print head and the platen are separated. This is applied to a printer in which the interval is adjusted. The basic configuration of the present invention includes a contact / separation mechanism that contacts and separates the print head with respect to the platen, a motor that drives the contact / separation mechanism, and a power transmission mechanism that transmits the driving force of the motor to the contact / separation mechanism. And a control means for adjusting the distance between the print head and the platen by controlling the drive of the motor. The power transmission mechanism includes a first lever that linearly moves in response to a driving force of a motor, a second lever that is coupled to the first lever so as to be linearly movable, and the second lever is a first lever. The first lever and the second lever are stretched so as to move linearly following the movement of the motor, and the driving force of the motor is transmitted to the contact / separation mechanism and the print head is pressed against the recording paper. When further movement of the two levers is prevented, the tension is changed to move both levers relative to each other, the first switch provided on the first lever or the second lever, and the first lever or the second lever. First switch that is provided on the first switch or the first lever or the second lever on the non-installation side of the first switch and that turns the first switch on and off when the levers move relative to each other by a predetermined amount. One piece and the second When the levers are provided on the first lever or the second lever on the non-installation side of the switch and both levers move relatively larger than the relative movement amount of both levers when the first switch is turned on / off, this movement causes the second switch to move. And a second actuating piece for turning on and off.

The control means stores the tension of the spring when the first switch is turned on / off and the tension of the spring when the second switch is turned on / off. When adjusting the distance from the platen, the motor is driven in the direction in which the print head approaches the platen, and then the motor is stopped when both the second switch and the first switch are switched. The tension of the spring when the first switch is turned on / off, the tension of the spring when the second switch is turned on / off, and the driving amount of the motor when the first switch is switched , a drive amount of the motor when the second switch is switched, the relative movement start position of the two levers on the basis of the calculated, apart print head the relative movement start position as a reference from the platen That the direction of the motor by a predetermined amount driven are to adjust the distance between the printing head and the platen. This control means stores the switch switching data of the first switch and the second switch, so that the position of the surface of the recording sheet, that is, the relative movement start position of both levers can be calculated and detected. If the above contact / separation mechanism is set so that the amount of movement of the print head and the rotation angle of the motor, that is, the number of input pulses, are in a linear relationship, the position of the paper surface, that is, the relative movement start position of both levers is detected. The calculation for doing so becomes easy.
Further, the second feature of the present invention is that when the above-mentioned control means adjusts the distance between the print head and the platen, the driving amount of the motor when the first switch is switched and when the second switch is switched. The paper quality of the recording paper is detected based on the amount of change from the driving amount of the motor, and the interval between the print head and the platen can be adjusted to an interval according to the paper quality of the recording paper. This is because the harder the paper quality, the smaller the amount of deformation due to the press after the print head comes into contact with the paper surface, so the rate at which the motor drive amount changes with respect to the relative movement amount between the first lever and the second lever is smaller. It is a thing that makes use of. When the two points are set to have a linear relationship, it means that the inclination angle of the straight line connecting the two points becomes large. Accordingly, the paper quality can be determined based on the rate of change in the relative amount of movement between the first lever and the second lever. Therefore, the distance between the platen and the print head can be adjusted according to the paper quality, and high-quality printing can be performed. Become.

  The printer of the present invention calculates the paper surface position of the recording paper from the measurement at a plurality of points in order to set the interval between the print head and the platen corresponding to the change in the paper thickness of the recording paper during printing. Therefore, it is possible to detect a good paper thickness under any environment. In particular, since the quality of the recording paper can be detected by measuring at a plurality of locations, high-quality printing is possible when recording paper with different paper quality is printed.

  The overall configuration of a printer embodying the present invention will be described. 1 to 4 show various modes of use of the printer. First, in the outer case 1 of the printer, a right side plate 11 (FIG. 5) and a left side plate 12 are erected and supported on the bottom face in proximity to both side surfaces of the outer case. The exterior case 1 has an openable / closable front cover 13 on the front surface (left side in FIG. 1), an openable / closable partition cover 14 inside the case, and an openable / closable upper cover 15 on the upper surface. A switching cover 16 that can be swung rearward is provided, and a rear cover 17 that is detachable is provided on the rear surface (right side of FIGS. 3 and 4). The guide pins 18 and 19 are provided so as to face each other.

  In this printer, the rear cover 17 is removed from the state shown in FIGS. 3 and 4, and the guide pins 18 and 19 are connected to the cut sheet feeder (CSF) 21 as shown in FIG. 1 or the rear tractor 22 as shown in FIG. Can be used. The CSF 21 or the rear tractor 22 is provided with guide grooves 21 a and 21 b or 22 a and 22 b (FIG. 2) that can be engaged with the guide pins 18 and 19. A front tractor 23 is provided in the outer case 1 so as to be swingable about a shaft 23a behind a lower end portion that is a swing center of the front cover 13.

  Next, the printing apparatus 3 will be described. 1 and 6, the print head 31 is mounted on a carriage 34 that moves in the left-right direction of the printer by upper and lower guide shafts 32, 33 whose both ends are supported by the side plates 11, 12. The lower guide shaft 33 penetrates the carriage 34, and the upper guide shaft 32 guides the carriage 34 while allowing the carriage 34 to move up and down. A platen 35 is provided at a position facing the print head 31, and both end portions thereof are supported by the side plates 11 and 12. As shown in FIG. 1, the ribbon cassette 36 is fixedly provided by a ribbon cassette support frame 37 at a position where the movement of the print head 31 is not hindered, and the ribbon is fed by a normal rotation drive of a ribbon feed motor 38 positioned behind. It is designed to send in one direction. An ink ribbon (not shown) is mounted on the ribbon cassette 36, and this ribbon is wound outside the moving range of the print head 31. The carriage 34 is driven to move in a direction perpendicular to the paper surface by a carriage motor (not shown). The ribbon cassette support frame 37 is fixedly installed between the side plates 11 and 12.

  Next, FIGS. 5 to 7 illustrate a mechanism for adjusting the parallelism between the guide shaft 33 and the platen 35 and the distance between the print head 31 and the platen 35 by moving the print head 31 forward and backward toward the platen 35. The description will be given with reference. FIG. 5 is an outer surface (right surface) of the right side plate 11, FIG. 7 is an outer surface (left surface) of the left side plate 12, and FIG. Show. Of these adjusting mechanisms, the parallelism adjusting device 4 will be described first. As described above, both end portions of the guide shaft 33 are supported by penetrating the left and right side plates 11 and 12 as shown in FIG. 6, but the through holes are elongated holes 11a, 12a, which serves as a guide means for guiding the guide shaft 33 in the direction in which the print head 31 contacts and separates from the platen 35. Therefore, the position of the guide shaft 33 can be finely adjusted in the vertical direction along these long holes. Eccentric bushes 40 and 41 having eccentric cam surfaces 40a and 41a are connected and fixed to the projecting ends of the guide shaft 33 from both side plates 11 and 12, respectively. The eccentric bushes 40 and 41 are provided with tooth profile portions 40b and 41b.

  These eccentric bushes 40 and 41 are provided as positioning members at positions in contact with the eccentric cam surfaces 40a and 41a. A pin 42 projects from the right side plate 11 and has an eccentric outer peripheral surface. A boss 43a is fitted, and a metal pipe 44 is rotatably fitted to the boss. The pipe 44 comes into contact with the eccentric cam surface 40a. The boss portion 43a is integrally provided with a parallelism adjusting lever 43, and this lever can swing around the pin. The click protrusion 43b provided at the tip of the parallelism adjusting lever 43 is selectively applied to the plurality of click holes 11b (FIG. 5) provided on the right side plate 11 so as to be aligned on the circumference around the pin 42. To be engaged. A pin 45 as a positioning member for the eccentric cam surface 41a protrudes from the left side plate 12, and the eccentric cam surface 41a is in contact with this pin. Eccentric cam surfaces 40a and 41a are always elastically contacted with pipe 44 or pin 45 by L-shaped guide shaft support levers 46 and 47 supported by center pins 46a and 47a (FIG. 7). Long holes 46b (FIG. 5) and 47b (FIG. 7) which are long in the left-right direction are provided at the lower ends of both levers 46 and 47, and both end portions of the guide shaft 33 pass through these long holes. Tension springs 48 and 48 are latched at the upper ends of both levers 46 and 47, and this spring provides a biasing force for elastically contacting the eccentric cam surfaces 40 a and 41 a to the pipe 44 or the pin 45 via the guide shaft 33. is doing.

  Since the parallelism adjusting device 4 between the guide shaft 33 and the platen 35 has such a configuration, when there is a problem with the parallelism between the print head 31 and the platen 35 during the assembly of the printer, the click protrusion 43b and the click hole. The engagement position with 11b is changed. As a result, the parallelism adjusting lever 43 swings, so that the boss portion 43a rotates about the pin 42, so that the position where the pipe 44 and the eccentric cam surface 40a are in contact slightly moves up and down. That is, when the small diameter portion of the boss portion 43a is in a position in contact with the eccentric cam surface 40a, the position in contact with the boss portion 43a slightly rises, and thus the right end portion of the guide shaft 33 rises. Conversely, when the large diameter portion of the boss portion 43a is in a position in contact with the eccentric cam surface 40a, the position in contact with the boss portion 43a is slightly lowered, so that the right end portion of the guide shaft 33 is lowered. In this way, the right end portion of the guide shaft 33 is raised and lowered with the left end portion of the guide shaft 33 as a reference, and the parallelism between the guide shaft 33 and the platen 35 can be adjusted by this raising and lowering. Since the movement of the guide shaft 33 is restricted by the long hole 11 a of the right side plate 11, the position facing the platen 35 is not changed.

  Next, the gap adjusting device 5 that adjusts the distance between the print head 31 and the platen 35 will be described in detail with reference to FIG. The gap adjusting device 5 includes a contact / separation mechanism 6 that contacts and separates the print head 31 by moving the print head 31 back and forth (up and down) with respect to the platen 35, a power transmission mechanism 8 that transmits the driving force of the motor 50 to the contact / separation mechanism 6, Control means for controlling the rotation of the motor 50. The drive source of the gap adjusting device 5 is a gap adjusting motor 50 fixed to the right side plate 11 as shown in FIGS. An intermediate gear 51 constituting the power transmission mechanism 8 meshes with the pinion 50a fixed to the drive shaft of the motor 50, and a gear 52 having a first notch meshes with the pinion 51a of this gear. A first lever 53 is connected to the gear 52 via a pin 53a. On the first lever 53, a first switch 54 and a second switch 59, which are micro switches, are fixed.

  On the other hand, the toothed portion 40b of the eccentric bush 40 fitted to the right end portion of the guide shaft 33 is engaged with a gear 55 having a second notch, and the second lever 56 is engaged with the gear via a pin 56a. It is connected. The first lever 53 and the second lever 56 are overlapped with each other at the ends opposite to the connecting portions of the pins 53a and 56a to the gears 52 and 55, and a tension spring 57 is interposed between the two levers. It is latched and is biased in a direction in which the ends approach each other. The spring 57 continues the rotation of the motor 50 in spite of the fact that the print head 31 presses against the surface of the recording paper, so that the relative movement amount between the first lever 53 and the second lever 56 is reduced. Works to absorb. The displacement of the print head 31 is performed by a cam formed on the bushing surface 40a of the eccentric bush 40. The cam surface of this cam is formed so that the displacement of the print head 31 becomes a straight line with respect to the change of the rotation angle. Therefore, the change in the number of pulses of the motor 50 and the change in the tension of the spring have a linear relationship.

  The second lever 56 is provided with a first operating piece 56b and a second operating piece 56c for releasing the operating protrusions of the first switch 54 and the second switch 59 by pressing and turning the switch on and off. Further, the corner portion of the notch portion of the gear 55 having the second notch portion is an operation piece 55a for pressing and releasing the operation protrusion of the initial switch 58 to turn this switch on and off. Normally, the operating protrusion of the first switch 54 is pressed by the first operating piece 56b by the tension spring 57, so that it is turned on. Under this state, the second switch 59 is in an off state. At this time, the operating projection of the initial switch 58 is not pressed by the operating piece 55a, so that it is in an off state. The switches 54, 58 and 59 constitute control means for controlling the driving of the motor 50 by on / off output (FIG. 10). It should be noted that the switches 54 and 59 may be provided on the second lever, each operating piece may be provided on the first lever 53, and one switch and each operating piece may be provided on each lever.

  Next, the system of the control means of the gap adjusting device 5 will be described with reference to FIG. A central part of this system is a control circuit (CPU) 81, and information is output to the initial switch 58, the first switch 54 and the second switch 59. The on / off operation of the initial switch 58 is directly output to the control circuit 81, but the on / off operation of the first switch 54 and the second switch 59 is output to the memory circuit 82. . The memory circuit 82 incorporates both RAM and ROM, and the ROM stores in advance the tension of the spring 57 when these switches 54 and 59 are turned on and off. These pieces of information are calculated by the calculation circuit 83 and the calculation result is output to the control circuit 81. The control circuit 81 incorporates a program for adjusting the gap and a comparator circuit for judging the paper quality from the movement amount of the print head 31 and the like. Information processed according to the program in the control circuit 81 is output to the motor 50 via the motor drive circuit 84, and the gap adjusting device 5 can be driven via the power transmission mechanism.

  Next, the operation of adjusting the distance between the platen 35 and the print head 31 by the gap adjusting device 5 will be described with reference to FIGS. When a print command is issued from an external device such as a computer, the paper is fed onto the platen 35 by the paper feed rollers 61 and 62 by a predetermined distance from the front end of the recording paper P1 by a paper feeding device, which will be described later in FIG. Next, the gap adjusting device 5 starts an interval adjusting operation between the platen 35 and the print head 31. First, when the motor pinion 50a of the motor 50 is rotated in the clockwise direction, this rotation is transmitted to the gear 52 through the intermediate gear 51, and this gear also rotates in the clockwise direction, thereby moving the first lever 53 in the left direction. Move (FIG. 8). This movement is transmitted to the second lever 56 via the first switch 54 and the first operating piece 56b, and the gear 55 having the second notch is rotated clockwise in FIG. 8 via the pin 56a. The bush 40 is rotated counterclockwise. By this rotation, the small diameter portion of the eccentric cam surface 40a comes into contact with the pipe 44, so that the guide shaft 33 moves away from the platen 35, that is, ascends (FIG. 6). Due to the clockwise rotation of the second gear 55, the operating piece 55a (FIGS. 5 and 6) of the second gear 55 approaches the initial switch 58 and finally presses its operating projection to switch the initial switch 58 on. The By switching the switch, the motor 50 is stopped and the raised position (home position) of the print head 31 is detected. The detected home position is stored in the storage circuit 82 (FIG. 10).

  Next, when the motor pinion 50a is rotated counterclockwise by re-driving the motor 50, this rotation is transmitted to the gear 52 via the intermediate gear 51, and the first lever 53 is moved rightward. Following this first lever 53, the second lever 56 also moves to the right, so that the gear 55 rotates counterclockwise, and the bush 40 meshing with the second gear 55 is thereby rotated clockwise. Rotate to. By this rotation, the large diameter portion of the eccentric cam surface 40a comes into contact with the pipe 44, so that the guide shaft 33 descends in a direction approaching the platen 35 (FIG. 6). As a result, the pressing state of the initial switch 58 by the operating piece 55a is released, and the switch is returned to the OFF state. Further, since the motor 50 continues to rotate, the print head 31 finally contacts the recording paper and moves forward to a position where it cannot be further lowered, and further advances while deforming the recording paper. It becomes a state. However, since the motor 50 continues to rotate, the second lever 56 can no longer follow the movement of the first lever 53 in the right direction, so that the first lever 53 extends the spring 57 while the second lever 56 extends. The relative movement with the lever 56 is started. Since the first switch 54 attached to the first lever 53 also moves in the right direction, the first operating piece 56b is separated from the operating protrusion of the first switch 54, and the first switch 54 is turned from on to off. Switch. The movement distance from the home position of the print head 31 at this time is stored in the storage circuit 83 as the number of rotation pulses (X1) of the motor 50. The tension (Y1) of the spring 57 at this time is stored in the storage circuit 82.

  When the rotation of the motor 50 is further continued, the first lever 53 is further pushed, the second switch 59 comes into contact with the second operating piece 56c, and the second switch 59 is switched from OFF to ON (FIG. 9). As a result, the motor 50 stops. The movement distance from the home position of the print head 31 at this time is stored in the storage circuit 83 as the number of rotation pulses (X2) of the motor 50. Similarly, the tension (Y2) of the spring 57 at this time is also stored in the memory circuit 83. Since the change between the number of rotation pulses (X) of the motor and the tension (Y) of the spring has a linear relationship as described above, the stored values (X1, Y1) and (X2, Y2) obtained by the above operation are used. ) Is obtained by the arithmetic circuit 83, the relative movement start position of the first lever 53, that is, the position of the paper surface, can be obtained by the number of pulses (X) from the home position. The above relationship is shown by a diagram in FIG. FIG. 2A shows a solid line obtained by taking data of ordinary recording paper such as copy paper. FIG. 2B shows a solid line obtained by taking data on a copy sheet formed by superposing a plurality of sheets.

The inclination angle (α) of these straight lines can be obtained by the ratio of the change in Y value (Y2−Y1) and the change in X value (X2−X1). The harder paper has a larger inclination angle (α). The softer the paper, the smaller. Therefore, standard values of these tilt angles are stored in advance in the storage circuit 82 and compared with the actual detection values, so that intervals according to the paper quality can be set, so that printing can be performed in an optimum state. Become. For example, an intermediate angle (α ₀ ) between both straight lines from the straight line angles (α _1, α ₂ ) of FIGS. (A) and (b) is stored in advance in the storage circuit 83 and calculated from the detected value. If the angle value (α ₁ ) is α ₁ > α _{0, the} paper is determined to be hard paper, and if α ₁ <α ₀ , the paper is determined to be soft paper, and the corresponding interval between the print head 31 and the platen 35 is selected. Is possible. Further, by determining the paper quality at a fine interval with a plurality of reference values to be compared, it is also possible to adjust the interval between the print head 31 and the platen 35 for a plurality of types of paper quality.

  As described above, when the accurate paper surface position is detected and the paper quality is determined, the print head 31 is moved backward from the paper surface by the number of pulses stored in the storage circuit 82, that is, to the home position side. If the distance between the print head 31 and the platen 35 is adjusted in this way, it is possible to always print the recording paper and the print head 31 at an appropriate distance.

  Next, the paper feeding device will be described. In this apparatus, as shown in FIGS. 1 to 4, paper feed rollers 61 and 62 are disposed before and after the platen 35. The paper feed rollers 61 and 62 are transmitted from a motor pinion of the paper feed motor 60 via a gear train (not shown), and the paper feed rollers 61 and 62 are driven to rotate in conjunction with each other. As shown in FIG. 1, driven rollers 61a and 62a provided on the print head 31 side are in elastic contact with the paper feed rollers 61 and 62, so that the paper feed rollers 61 and 62 and the driven rollers 61a and 61a, Paper feed is performed in pairs with 62a. Further, if the driven roller 61a on the side close to the front cover 13 is provided at a position close to the print head 31 for the purpose of miniaturization, for example, the presence of the driven roller 61a at the time of replacement of the print head, etc. May disturb you. Therefore, a switching mechanism (not shown) that moves the driven roller 61a to a position that does not interfere with the replacement operation of the print head 31 is employed, and a paper feeding position where the driven roller 61a elastically contacts the paper feeding roller 61 and a non-paper feeding position. And can be switched to.

  The printer has the following four modes of use depending on the type of the paper feeder. First, as shown in FIG. 1, the front cover 13 is opened, and two sheet receivers 13a that are foldable inwardly with a sufficient interval to support the recording sheet are provided. The cut sheet P1 sent out from the CSF 21 on the rear side is printed by the printing device 3 in a state in which the front tractor 23 swings downward to the right. In this printer, there are two paper discharge positions, one of which is a paper discharge position where the paper is discharged forward, that is, leftward as it is printed, and stacked on the table 115 swinging with the front tractor 23 and the paper receiver 13a. . In the other case, the upper cover 15 is opened to expose the sheet receiver 15a and the upper discharge port 1a in the upper cover, and the switching lever of the switching lever device 9 after printing on the cut sheet P1. 90 is in the state of a chain line. The sensor (not shown) senses that the cut sheet P1 has passed through the printing device 3, and the paper feed motor 60 is reversed by the output of the sensor and the switching lever device 9 is displaced to the chain line state. Since P1 is conveyed rearward again and is now guided upward, it exits from the first upper paper discharge outlet 1a and is stacked on the upper cover 15 and the paper receiver 15a. This is another paper discharge position.

  Second, as shown in FIG. 2, the continuous paper P <b> 2 fed from the rear tractor 22 is printed by the printing device 3 in a state where the front cover 13 is opened and the front tractor 23 is horizontal. There is a paper discharge position where the paper is discharged as it is after printing and is stacked in a folded state on a table (not shown) in front of the front cover 13. As shown in FIG. 3, in the state where the front cover 13 is opened and the front tractor 23 is horizontal, the cut sheets P3 are manually fed from the front cover 13 one by one. 3 is a usage pattern printed by No. 3. In this form of use, there are two paper discharge positions, one of which is detected by a sensor (not shown) that the cut sheet P3 has passed through the printing apparatus 3, and the paper feed motor 60 is reversed by the output of this sensor. The cut sheet is conveyed in the direction of returning to the front, and is a discharge position where the cut sheet returns to the front cover 13 again. In the other case, the upper cover 15 is opened in advance to expose the sheet receiver 15a and the first upper discharge port 1a, and the switching lever device 9 is set in a chain line state. Cut sheets P3 are manually fed from the front cover 13 one by one, printed by the printing device 3, conveyed rearward as it is, guided further upward, and from the first upper discharge port 1a to the upper cover 15 The paper discharge position is stacked on the paper receiver 15a.

  As shown in FIG. 4, continuous paper P4 inserted from the insertion port 1b provided below the front cover 13 is fed out by the front tractor 23 in a state where the front tractor 23 swings to the right as shown in FIG. This is a usage pattern printed by the printing device 3. In this case, there are two paper discharge positions, one of which is a paper discharge position where the paper is discharged rearward as it is after printing and is discharged from the rear paper discharge port 1c provided below the rear cover 17. In the other case, the switching lever device 9 is set in a chain line state in advance, and the switching cover 16 is swung like a chain line to close the first upper discharge port 1a and the second upper discharge port 1d. Keep open. The printed continuous paper P4 is a paper discharge position that is guided upward after printing and is guided to the rear of the printer through the second upper paper discharge port 1d.

  Therefore, the sheet conveyance path in the four usage modes will be described in detail. As shown in FIGS. 1 to 4, the paper transport path in the printing section by the print head 31, the platen 35, and the paper feed rollers 61 and 62 before and after the platen is horizontally arranged, and printing is performed here. There are four paths through which the paper is discharged. That is, the first path is a path for discharging paper forward, which is printed using the CSE 21 described with reference to FIG. 1 and printed using the tractor 22 described with reference to FIG. There are three ways of printing on the cut sheet P3 by manual feeding described in FIG. 3 and returning to the front after the feeding direction is reversed by the printing unit. The second path is a path to be discharged to the first upper discharge port 1a, and is printed using the CSF 21 described with reference to FIG. There are two ways of printing on the sheet by manual feed described in FIG. The third path is a path for discharging paper to the second upper paper discharge port 1d, and is printed when using the front tractor 23 described in FIG. The fourth path is a path where paper is discharged to the rear paper discharge port 1c and is printed using the front tractor 23 described with reference to FIG. Since the first upper paper discharge port 1a, the second upper paper discharge port 1d, and the rear paper discharge port 1c are all located behind the printing unit, the sheet conveyed rearward from the printing unit is Depending on the switching posture of the switching lever device 9, switching is performed between the upper side and the rear side, and then the switching is performed manually by switching the switching cover 16 to the first upper discharge port 1a or the second upper discharge port 1d.

  Although the invention has been described with respect to four types of printers, it is also applicable to other types of printers. Further, the above description has been made on the assumption of a wire dot printer, but it can also be applied to various ink jet printers.

  The present invention relates to a printer as an output device such as a computer, and is industrially usable for both manufacturing and use.

It is sectional drawing which shows the 1st usage pattern of this invention. It is sectional drawing which shows the 2nd usage pattern of this invention. It is sectional drawing which shows the 3rd usage pattern of this invention. It is sectional drawing which shows the 4th usage pattern of this invention. It is a right view explaining the adjustment apparatus of the parallelism with respect to the platen of a print head, and the adjustment apparatus of the gap between both. It is sectional drawing which expand | deploys and demonstrates both the adjustment apparatuses of FIG. It is a left view explaining the adjustment apparatus of a print head and a platen. It is the front view which expanded and showed the mechanism of the gap adjustment device in which the 1st switch is off and the 2nd switch is on. It is the front view which expanded and showed the mechanism of the gap adjustment device in which the 1st switch is off and the 2nd switch is on. It is a block diagram which shows the system of the control means of a gap adjustment apparatus. The relationship between the pulse number from a home position and the tension | tensile_strength of a spring is shown, (a) is a diagram which shows the example of standard paper quality, (b) is a diagram which shows the example of soft paper quality.

Explanation of symbols

P (P1 to P4) Recording paper 5 Gap adjusting device 6 Contact / separation mechanism 8 Power transmission mechanism 31 Print head 35 Platen 50 Motor 53, 56 Lever 54, 58, 59 Switch 56b, 56c Actuating piece 57 Spring

Claims (2)

The print head is pressed against the recording paper inserted between the two by bringing the print head closer to the platen, and the print head is separated from the platen by a predetermined amount with reference to the position, and the print head and the platen A printer for adjusting the interval of
A contact / separation mechanism for contacting and separating the print head with respect to the platen;
A motor for driving the contact / separation mechanism;
A power transmission mechanism for transmitting the driving force of the motor to the contact / separation mechanism;
Control means for adjusting the distance between the print head and the platen by controlling the drive of the motor;
The power transmission mechanism includes a first lever that linearly moves in response to the driving force of the motor, a second lever that is coupled to the first lever so as to be relatively linearly movable, and the second lever that is the first lever. It is stretched between the first lever and the second lever so as to move linearly following the lever, and the driving force of the motor is transmitted to the contact / separation mechanism and the print head is pressed against the recording paper. A spring that changes the tension to move both levers relative to each other when the second lever is prevented from further movement, a first switch provided on the first lever or the second lever, and the first switch. The second switch provided on one lever or the second lever and the first switch on the non-installation side of the first switch or the second lever provided on the first lever or the second lever are moved relative to each other by a predetermined amount. The first actuating piece for turning on / off the first switch and the first lever or the second lever on the non-installation side of the second switch, and the both levers turn on / off the first switch. A second actuating piece for turning on and off the second switch by the movement when the relative movement is larger than the relative movement amount of the two levers when turned off,
The control means stores the tension of the spring when the first switch is turned on / off and the tension of the spring when the second switch is turned on / off , When adjusting the distance from the platen, the print head drives the motor in a direction approaching the platen, and when both the switches are switched thereafter, the drive of the motor is stopped and the first The tension of the spring when the switch is turned on / off, the tension of the spring when the second switch is turned on / off , the driving amount of the motor when the first switch is switched, and the first a driving amount of the motor 2 when the switch is switched to calculate a relative movement start position of the two levers on the basis of, the print head is the relative movement start position as a reference The direction away from the serial platen by a predetermined amount driving the motor printer, characterized in that for adjusting the distance between the print head and the platen. 2. The control means according to claim 1, wherein the control means includes: a tension of the spring when the first switch is turned on / off; a tension of the spring when the second switch is turned on / off ; the print head; The driving amount of the motor when the first switch is switched at the time of adjusting the distance from the platen and the driving amount of the motor when the second switch is switched are compared with the driving amount calculated from the driving amount of the motor. A printer characterized in that the quality of the recording paper is detected based on the amount of change in tension, and the interval between the print head and the platen is adjusted to an interval corresponding to the paper quality.