JP2008044299A - Printer and printer control method - Google Patents

Abstract

A printer having a configuration capable of improving throughput is provided.
A controller 50 that controls the transport motor 14 and the supply motor 31 so that the peripheral speeds of the supply roller 27 and the transport roller 4 that transport the print medium in cooperation with the transport roller 4 are substantially the same. When the transport motor 14 is rotated with the first command rotational speed based on the control command output from the control command section as the target rotational speed, the transport motor 14 cannot be appropriately controlled, or the second command rotational speed based on the control command. When the supply motor 31 is rotated with the target rotation speed as the target rotational speed, when the supply motor 31 cannot be appropriately controlled, the conveyance motor 14 and the supply motor 31 can be appropriately controlled during the next intermittent conveyance. The rotation of the transport motor 14 is controlled with a rotation speed lower than the first command rotation speed as a target rotation speed, and a supply motor with a rotation speed lower than the second command rotation speed as a target rotation speed 1 controls rotation.
[Selection] Figure 2

Description

  The present invention relates to a printer and a printer control method.

  As an inkjet printer that prints on a printing medium such as printing paper, a paper feed roller that supplies the printing paper to the inside of the printer, and a paper that conveys the printing paper when printing on the printing paper supplied to the inside of the printer A printer including a feed roller is known (for example, see Patent Documents 1 and 2).

  In the printer described in Patent Document 1, the paper feed roller is connected to a paper feed motor that rotationally drives the paper feed roller via a clutch. The printing paper set in the paper feed hopper is first transported to the position of the paper feed roller by the paper feed roller connected to the paper feed motor. When the printing paper is conveyed to the position of the paper feeding roller, the paper feeding roller and the paper feeding motor are disconnected, and the subsequent printing paper is conveyed by the paper feeding roller.

  In the printer described in Patent Document 2, the paper feed roller and the paper feed roller are rotationally driven by separate motors. Also in this printer, similarly to the printer described in Patent Document 1, the printing paper is conveyed to the position of the paper feeding roller by the paper feed roller, and the subsequent printing paper is conveyed by the paper feeding roller.

JP 2003-72964 A JP 2006-117385 A

  In recent years, in the printer market, improvement in throughput (the number of printed sheets per unit time) during continuous printing in which printing is continuously performed on a plurality of printing papers is required. However, in the printers described in Patent Documents 1 and 2, the printing paper is taken up to the position of the paper feed roller by the paper feed roller, and the subsequent conveyance of the printing paper is performed by the paper feed roller. That is, the printing operation or paper discharge operation and the paper feeding operation are separate operations. Therefore, the printers described in Patent Documents 1 and 2 have a limit in improving throughput.

  Accordingly, an object of the present invention is to provide a printer having a configuration capable of further improving the throughput. Another object of the present invention is to provide a printer control method capable of further improving the throughput.

  In order to solve the above-described problems, a printer of the present invention includes a conveyance roller that can intermittently convey a print medium supplied from a medium setting unit on which a print medium before printing is set, and a conveyance motor that drives the conveyance roller. A supply roller capable of intermittently conveying the print medium supplied from the medium setting unit in cooperation with the conveyance roller, a supply motor for driving the supply roller, and a conveyance A control unit that controls the rotation speed of the conveyance motor and the supply motor so that the peripheral speed of the roller and the peripheral speed of the supply roller are substantially the same, and the control unit outputs a control command to the control unit When the conveyance motor is rotated with the first command rotation number of the conveyance motor based on the control command output from the unit as the target rotation number, the circumferential speed of the conveyance roller and the circumferential speed of the supply roller are substantially the same. And / or when the supply motor is rotated with the second command rotation speed of the supply motor based on the control command as the target rotation speed, the peripheral speed of the transport roller and the peripheral speed of the supply roller are not substantially the same. The rotation speed of the conveyance motor is controlled to be a rotation speed lower than the first command rotation speed so that the circumferential speed of the conveyance roller and the circumferential speed of the supply roller at the next intermittent conveyance are substantially the same, and The rotation of the supply motor is controlled with a rotation speed lower than the second command rotation speed as a target rotation speed.

  In the printer of the present invention, the control unit rotates the conveyance motor and the supply motor so that the peripheral speed of the supply roller that conveys the print medium in cooperation with the conveyance roller is substantially the same as the peripheral speed of the conveyance roller. Is controlling. Therefore, the supply roller and the conveyance roller can be rotated in synchronization. Therefore, the print medium supply operation can be performed without hindering the print medium discharge operation and the print operation. That is, the printing operation, the discharge operation, and the supply operation can be performed as a series of operations, and the throughput can be further improved during continuous printing. Further, since the supply roller and the conveyance roller can be rotated in synchronization, the print medium can be appropriately conveyed between the supply roller and the conveyance roller. As a result, it is possible to suppress the generation of sound of the print medium that may occur during conveyance (by the print medium sagging or stretching) due to a change in tension applied to the print medium.

  Furthermore, in the present invention, when the conveyance motor is rotated with the first command rotational speed based on the control command output from the control command section as the target rotational speed, the circumferential speed of the transport roller and the circumferential speed of the supply roller are substantially the same. If the supply motor is rotated with the second command rotational speed based on the control command as the target rotational speed, the peripheral speed of the transport roller and the peripheral speed of the supply roller are not substantially the same, The control unit controls the rotation of the transport motor while setting the rotational speed lower than the first command rotational speed as the target rotational speed so that the peripheral speed of the transport roller and the peripheral speed of the supply roller during the intermittent transport are substantially the same. The rotation of the supply motor is controlled with a rotational speed lower than the command rotational speed as a target rotational speed. Therefore, in the present invention, when the command rotational speed based on the control command from the control command unit is set as the target rotational speed, the transport motor and the supply motor are set so that the peripheral speed of the transport roller and the peripheral speed of the supply roller are substantially the same. If it is not possible to control appropriately, the supply roller and the conveyance roller are appropriately set by setting the rotation number lower than the first command rotation number and the second command rotation number as the target rotation number of the conveyance motor and the supply motor. It can be rotated in synchronization with.

  In order to solve the above problems, a printer of the present invention drives a conveyance roller that can intermittently convey a print medium supplied from a medium setting unit on which a print medium before printing is set, and a conveyance roller. A feeding motor, a supply roller capable of supplying the printing medium from the medium setting unit, and capable of intermittently conveying the printing medium supplied from the medium setting unit in cooperation with the feeding roller, and a feeding motor for driving the feeding roller; A control unit that controls the rotation speed of the transport motor and the supply motor so that the peripheral speed of the transport roller and the peripheral speed of the supply roller are substantially the same, and the control unit outputs a control command to the control unit. Convey so that the peripheral speed of the transport roller and the peripheral speed of the supply roller at the next intermittent transport are substantially the same based on the command transport amount of the print medium based on the control command output from the command unit And selecting the target rotation speed of the target speed and feed motor over data.

  In the printer of the present invention, the control unit rotates the conveyance motor and the supply motor so that the peripheral speed of the supply roller that conveys the print medium in cooperation with the conveyance roller is substantially the same as the peripheral speed of the conveyance roller. Is controlling. Therefore, the throughput can be further improved during continuous printing. In addition, it is possible to suppress generation of sound of the print medium that may occur during conveyance due to a change in tension applied to the print medium. Further, in the present invention, the control unit determines whether the peripheral speed of the transport roller and the peripheral speed of the supply roller at the next intermittent transport are based on the command transport amount of the print medium based on the control command output from the control command unit. The target rotational speed of the transport motor and the target rotational speed of the supply motor are selected so as to be substantially the same. Therefore, in this invention, a supply roller and a conveyance roller can be rotated synchronizing it appropriately.

  In the present invention, the printer includes a first encoder connected to the control unit and capable of detecting the rotational speed of the transport motor, and a second encoder connected to the control unit and capable of detecting the rotational speed of the supply motor. The unit preferably stops the transport motor and the supply motor when an output signal from at least one of the first encoder and the second encoder cannot be detected. When an output signal from at least one of the first encoder and the second encoder cannot be detected, an abnormal situation has occurred. With this configuration, it is possible to prevent clogging of the print medium and damage inside the printer.

  Furthermore, in order to solve the above-described problems, a printer control method of the present invention includes a conveyance roller that is driven by a conveyance motor and conveys a print medium supplied from a medium setting unit on which a print medium before printing is set; A supply roller that is driven by a supply motor and rotates a supply roller that supplies a printing medium from the medium setting unit at substantially the same peripheral speed, and a printing medium supplied from the medium setting unit by cooperating the transport roller and the supply roller. When the conveyance motor is rotated using the conveyance step of intermittent conveyance and the first command rotation number of the conveyance motor based on the control command output from the control command unit as the target rotation number, the peripheral speed of the conveyance roller and the circumference of the supply roller When the speed is not substantially the same and / or when the supply motor is rotated with the second command rotational speed of the supply motor based on the control command as the target rotational speed, When the peripheral speed of the roller and the peripheral speed of the supply roller are not substantially the same, the peripheral speed of the transport roller and the peripheral speed of the supply roller at the transport step are lower than the first command rotational speed so that they are substantially the same. A rotation speed setting step for setting the rotation speed as a target rotation speed of the conveyance motor and setting a rotation speed lower than the second command rotation speed as the target rotation speed of the supply motor.

  In the printer control method of the present invention, in the transport step, the transport roller and the supply roller are rotated at substantially the same peripheral speed, and the print medium is transported by the cooperation of the transport roller and the supply roller. Therefore, the supply roller and the conveyance roller can be rotated in synchronization, and the throughput can be further improved during continuous printing. In addition, the print medium can be appropriately conveyed between the supply roller and the conveyance roller, and the generation of sound on the print medium can be suppressed.

  Further, in the present invention, in the rotation speed setting step, when the transport motor is rotated with the first command rotation speed based on the control command output from the control command section as the target rotation speed, the peripheral speed of the transport roller and the peripheral speed of the supply roller are increased. When the speed is not substantially the same and / or when the supply motor is rotated with the second command rotational speed based on the control command as the target rotational speed, the peripheral speed of the transport roller and the peripheral speed of the supply roller are substantially the same. If not, the rotation speed lower than the first command rotation speed is set as the target rotation speed of the transfer motor so that the peripheral speed of the transfer roller and the peripheral speed of the supply roller in the transfer step are substantially the same. A rotational speed lower than the command rotational speed is set as the target rotational speed of the supply motor. Therefore, it is possible to rotate the supply roller and the conveyance roller in synchronization with each other.

  Furthermore, in order to solve the above-described problems, a printer control method of the present invention includes a conveyance roller that is driven by a conveyance motor and conveys a print medium supplied from a medium setting unit on which a print medium before printing is set. The print medium driven by the supply motor and rotated at substantially the same peripheral speed as the supply roller for supplying the print medium from the medium setting unit, and supplied from the medium setting unit by cooperating the transport roller and the supply roller The peripheral speed of the transport roller and the peripheral speed of the supply roller at the transport step are substantially the same based on the transport step for intermittent transport of the print medium and the command transport amount of the print medium based on the control command output from the control command unit. And a rotation speed selection step of selecting a target rotation speed of the transport motor and a target rotation speed of the supply motor.

  In the present invention, in the transport step, the transport roller and the supply roller are rotated at substantially the same peripheral speed, and the print roller is transported in cooperation with the transport roller and the supply roller. Therefore, the throughput can be further improved during continuous printing. Moreover, it is possible to suppress the generation of sound on the print medium. Further, in the present invention, in the rotation speed selection step, the peripheral speed of the transport roller and the peripheral speed of the supply roller in the transport step are determined based on the command transport amount of the print medium based on the control command output from the control command unit. The target rotational speed of the transport motor and the target rotational speed of the supply motor are selected so as to be substantially the same. Therefore, in this invention, a supply roller and a conveyance roller can be rotated synchronizing it appropriately.

  Hereinafter, a printer and a printer control method according to an embodiment of the present invention will be described with reference to the drawings.

(Schematic configuration of the printer)
FIG. 1 is a side view showing a schematic configuration of a main part of a printer 1 according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing a schematic configuration of a drive unit such as the PF drive roller 4 shown in FIG. 3 is a diagram for explaining the operation of the paper feed hopper 26 and the retard roller 28 shown in FIG. 1. FIG. 3A shows the inside of the printer 1 when the lower end of the paper feed hopper 26 and the retard roller 28 are raised. (B) shows that the lower end of the paper feed hopper 26 and the retard roller 28 are lowered so that the printing paper P cannot be supplied to the inside of the printer 1. It shows the state.

  The printer 1 of the present embodiment is an ink jet printer that performs printing by ejecting ink droplets onto a printing paper P that is a printing medium. Both the front side (left side in FIG. 1) and the rear side (right side in FIG. 1) The printing paper P can be supplied from the side. As shown in FIG. 1, the printer 1 transports a print sheet P supplied from a carriage 3 on which a print head 2 for ejecting ink droplets is mounted, a paper feed hopper 26 and the like, which will be described later, in the sub-scanning direction SS. A PF drive roller 4 as a transport roller, a PF driven roller 5 that transports the print paper P together with the PF drive roller 4, a paper discharge drive roller 6 that discharges the print paper P to the outside of the printer 1, and a paper discharge driven roller 7. A platen 8 facing the ink ejection surface (the lower surface in FIG. 1) of the print head 2, a paper detection device 9 for detecting the passage of the print paper P supplied from the paper feed hopper 26, etc., and the print head 2, a front paper feeding mechanism 10 for supplying the printing paper P from the front side toward the printing area where printing is performed, and a rear paper feeding mechanism 11 for supplying the printing paper P from the rear side toward the printing area. It is equipped with a. In addition to the printing paper P such as plain paper used for normal document printing, photographic paper used for photo printing, thick paper thicker than plain paper or photographic paper, etc. And transparent films such as OHP sheets.

  As shown in FIG. 2, the PF drive roller 4 is connected to a PF motor 14 serving as a transport motor directly or via a gear or the like not shown. The PF motor 14 of this embodiment is a DC (direct current) motor. In this embodiment, PWM control is adopted as a method for controlling the PF motor 14, and the current rotational speed (current rotational speed) of the PF motor 14 is set to the target rotational speed by combining proportional control, integral control, and differential control. PID control, which is control for convergence to (target rotational speed), is employed. The PF driven roller 5 is urged toward the PF driving roller 4 by a spring (not shown) and rotates together with the PF driving roller 4.

  As shown in FIG. 2, the paper discharge driving roller 6 is connected to the PF driving roller 4 via a transmission mechanism such as a pulley 18 and a belt 19. The rotation of the paper discharge driving roller 6 is synchronized with the rotation of the PF driving roller 4. That is, the paper discharge driving roller 6 rotates at a circumferential speed substantially the same as the circumferential speed of the PF driving roller 4. The paper discharge driven roller 7 is urged toward the paper discharge drive roller 6 by a spring (not shown) and rotates together with the paper discharge drive roller 6. The paper detection device 9 is an optical detection device in which a light emitting element and a light receiving element (not shown) are arranged to face each other in the vertical direction, and one end in the width direction of the printing paper P passing between the light emitting element and the light receiving element. Detect the part.

  The front paper feed mechanism 10 includes a paper feed cassette 20 in which the print paper P supplied from the front side is set, a front paper feed roller 21 that supplies the print paper P in the paper feed cassette 20 to the inside of the printer 1, And a conveyance path 23 through which the printing paper P taken in from the front side passes. The front paper feed roller 21 is attached to the tip of an arm 22 configured to be swingable about a rotation shaft 22 a and is in pressure contact with the upper surface of the printing paper P. The front paper feed roller 21 conveys the printing paper P into the printer 1 until the leading edge of the printing paper P reaches the PF driving roller 4.

  The rear paper feeding mechanism 11 prints the paper hopper 26 as a medium setting unit on which the printing paper P before printing supplied from the rear side is set, and the printing paper P on the paper feeding hopper 26 by the print head 2. Are provided with a rear feed roller 27 as a supply roller for feeding toward the printing area where the printing is performed, and a retard roller 28 for preventing double feeding of the printing paper P.

  As shown in FIG. 2, the rear paper feed roller 27 is connected to an ASF motor 31 as a supply motor via a gear train 29 and a planetary gear train 30. The front paper feed roller 21 is also connected to the ASF motor 31 via the planetary gear train 30 and the like (illustration of the front paper feed roller 21 is omitted in FIG. 2). In the present embodiment, when the ASF motor 31 rotates in one direction by the action of the planetary gear train 30, the rear paper feeding roller 27 rotates, and when the ASF motor 31 rotates in the other direction, the front paper feeding roller 21 rotates. The ASF motor 31 of this embodiment is a DC motor, and is PWM-controlled and PID-controlled as with the PF motor 14.

  The paper feed hopper 26 is a plate-like member on which the printing paper P can be placed, and can swing around a rotation shaft 26a provided on the upper end side. The retard roller 28 is disposed at a position facing the diagonally lower side of the rear paper feed roller 27 and is rotatably held by an arm (not shown) configured to be swingable about a rotation shaft (not shown). . By rotation of a cam (not shown), the paper feed hopper 26 swings around the rotation shaft 26a, and the arm holding the retard roller 28 also swings. By this swinging, the lower end portion of the paper feed hopper 26 is urged toward the rear paper feed roller 27 and is separated from the rear paper feed roller 27. Further, by this swinging, the retard roller 28 is pressed against the rear paper feed roller 27 and is separated from the rear paper feed roller 27. That is, as the cam rotates, the lower end portion of the paper feed hopper 26 and the retard roller 28 rise as shown in FIG. 3 (A), and the lower end portion of the paper feed hopper 26 as shown in FIG. 3 (B). And the retard roller 28 descends. The state shown in FIG. 3A is a state in which the printing paper P can be supplied to the inside of the printer 1. The state shown in FIG. 3B is a state in which the printing paper P cannot be supplied from the rear side to the inside of the printer 1.

  Further, as shown in FIG. 2, the printer 1 includes a PF encoder 40 as a first encoder for detecting the rotational speed of the PF motor 14, and a second encoder for detecting the rotational speed of the ASF motor 31. The ASF encoder 41 is provided. The PF encoder 40 includes a rotary scale 43 fixed to the rotating shaft of the PF drive roller 4 and a photosensor 44 having a light emitting element and a light receiving element (not shown). The ASF encoder 41 includes a rotary scale 45 fixed to the output shaft of the ASF motor 31 and a photosensor 46 having a light emitting element and a light receiving element (not shown). Output signals from the PF encoder 40 and the ASF encoder 41 are input to a control unit 50 that performs various controls of the printer 1.

  In this embodiment, a rectangular pulse signal is output from the PF encoder 40 and the ASF encoder 41, or a rectangular shape is output by the control unit 50 based on an output signal from the PF encoder 40 or the ASF encoder 41. A pulse signal is generated. Based on this rectangular pulse signal, the rotational speed of the PF motor 14 and the ASF motor 31 is detected. Hereinafter, based on the output signal from the PF encoder 40 or based on the output signal from the PF encoder 40, the pulse signal generated by the control unit 50 is set as the PF pulse signal and output from the ASF encoder 41, or the ASF encoder Based on the output signal from 41, the pulse signal generated by the control unit 50 is defined as an ASF pulse signal.

(Schematic configuration of control unit)
FIG. 4 is a block diagram showing a schematic configuration of the control unit 50 and its peripheral devices shown in FIG. FIG. 5 is a block diagram schematically showing a part of the internal configuration of the DC unit 60 shown in FIG. 4 and 5 show only the configuration of the control unit 50 related to the control of the PF motor 14 and the ASF motor 31.

  As shown in FIG. 4, the control unit 50 includes a bus 51, a CPU 52, a ROM 53, a RAM 54, a nonvolatile memory 55, an ASIC 56, a PF motor driving circuit 57, an ASF motor driving circuit 58, and the like. The bus 51 is a signal line that connects each component of the control unit 50, and each component of the control unit 50 exchanges data via the bus 51. The CPU 52 performs arithmetic processing for executing a control program stored in the ROM 53 or the like. The ROM 53 stores a control program for the printer 1 and the like. The RAM 54 temporarily stores data being calculated by the CPU 52, and the nonvolatile memory 55 stores various data that need to be saved even after the printer 1 is turned off. The ASIC 56 is configured to receive various control commands output from the control command unit 59.

  The speed control of the PF motor 14 and the ASF motor 31 is performed by the cooperation of the CPU 52 and the ASIC 56. That is, the CPU 52 and the ASIC 56 constitute a DC unit 60 that is a control circuit for performing speed control of the PF motor 14 and the ASF motor 31. Specifically, in the DC unit 60, the CPU 52 performs calculations for speed control of the PF motor 14 and the ASF motor 31 based on a signal input from the PF encoder 40 or the ASF encoder 41 via the ASIC 56. The ASIC 56 receives a signal from the PF encoder 40 or the ASF encoder 41 or the like and outputs a signal for controlling the PF motor 14 or the ASF motor 31 based on the calculation result in the CPU 52 and the PF motor drive circuit 57 and Output to the ASF motor drive circuit 58. Since the PF motor 14 and the ASF motor 31 of this embodiment are PID-controlled, the DC unit 60, as schematically shown, as shown in FIG. 5, a speed calculation unit 61 and a position calculation unit for performing PID control. 62 and a PID control unit 63.

  The speed calculation unit 61 calculates the current rotation speed (current rotation speed) of the PF motor 14 based on the signal input from the PF encoder 40, and the current speed of the ASF motor 31 based on the signal input from the ASF encoder 41. The rotational speed (current rotational speed) is calculated, and a signal corresponding to each rotational speed is output to the PID control unit 63. The position calculation unit 62 calculates the current rotation distance of the PF motor 14 based on the signal input from the PF encoder 40 and calculates the current rotation distance of the ASF motor 31 based on the signal input from the ASF encoder 41. Then, a signal corresponding to each rotation distance is output to the PID control unit 63.

  The PID control unit 63 first determines the difference between the target stop position and the current rotation distance from the target stop position corresponding to the next stop position of the printing paper P and the current rotation distance input from the position calculation unit 62. Calculate the position deviation. Further, based on the position deviation signal, the target rotational speed (target rotational speed) corresponding to the current rotational distance of the PF motor 14 or the ASF motor 31 is read from the target speed table stored in the ROM 53 and input from the speed calculation unit 61. A speed deviation which is a difference between the target rotational speed and the current rotational speed is calculated from the current rotational speed and the target rotational speed. Thereafter, based on the speed deviation, a proportional control value, an integral control value, and a differential control value are calculated, and these are added to output a PID control signal.

  The PF motor drive circuit 57 outputs a PWM drive signal for PWM control of the PF motor 14 by a signal from the DC unit 60. Similarly, the ASF motor drive circuit 58 outputs a PWM drive signal for PWM control of the ASF motor 31 by a signal from the DC unit 60.

  The control command unit 59 outputs a control command for intermittently transporting the printing paper P to the control unit 50. Specifically, the control command unit 59 of the present embodiment sets the transport amount (intermittent transport amount) at the time of intermittent transport of the printing paper P as a predetermined transport amount at the time of predetermined print control, and the PF motor 14 at the time of intermittent transport and A control command for setting the rotation speed of the ASF motor 31 at a constant speed to a predetermined rotation speed is output to the control unit 50. Further, the control command unit 59 of the present embodiment may output only a control command for setting the intermittent transport amount of the printing paper P to a predetermined transport amount to the control unit 50. Hereinafter, a method for controlling the conveyance of the printing paper P based on the control command from the control command unit 59 will be described.

(Method of printing paper conveyance control)
FIG. 6 is a diagram illustrating a state in which the printing paper P is being conveyed during continuous printing in the draft printing mode. FIG. 7 is a table showing the relationship between the transport speed and the minimum transport amount of the printing paper P in the constant speed region of the PF drive roller 4 and the rear paper feed roller 27 shown in FIG.

  In this embodiment, during continuous printing in which printing is continuously performed on a plurality of printing papers P, printing paper P supplied from the rear side in a draft printing mode in which ink consumption is saved and high-speed printing is performed instead of reducing the resolution. When the printing paper P is intermittently transported after being transported from the paper feeding hopper 26 to the PF driving roller 4 by the rear paper feeding roller 27, the PF driving roller 4 and the paper ejection driving roller 6 are used. In addition, a rear paper feed roller 27 is used. That is, in the draft printing mode, the PF driving roller 4 and the paper discharge driving roller 6 driven by the PF motor 14 and the rear paper feeding roller 27 driven by the ASF motor 31 cooperate to perform printing by the carriage 3. During the operation, the printing paper P is intermittently conveyed. Therefore, during continuous printing in the draft printing mode, synchronized control is performed in which the PF drive roller 4, the paper discharge drive roller 6, and the rear paper feed roller 27 are rotated synchronously (that is, at the same peripheral speed). Printing paper P is continuously conveyed.

  Specifically, a speed profile indicating the relationship between the rotational distance of the PF drive roller 4 and the target peripheral speed (target transport speed of the printing paper P by the PF drive roller 4), the rotational distance of the rear paper feed roller 27, and the target peripheral speed. The target speed tables of the PF motor 14 and the ASF motor 31 are set so that the speed profiles indicating the relationship with the speed (target conveyance speed of the printing paper P by the rear paper feed roller 27) are substantially the same, and the ROM 53 Is remembered. The PF motor 14 and the ASF motor 31 are PID-controlled according to these target speed tables. During continuous printing in the draft printing mode, when one printing paper P is conveyed by both the PF driving roller 4 and the rear paper feeding roller 27, the activation timing of the PF motor 14 is activated by the activation of the ASF motor 31. It is later than the timing. Therefore, the printing paper P being transported is slack between the PF drive roller 4 and the rear paper feeding roller 27 as shown by a two-dot chain line in FIG. 6, and the printing paper P at the time of stopping is shown by a solid line in FIG. As shown, the slack is taken.

  Here, in this embodiment, the target rotational speed at the constant speed when the PF motor 14 and the ASF motor 31 are actually driven (that is, the printing paper in the constant speed region of the PF drive roller 4 and the rear paper feed roller 27). P target conveyance speed) is set stepwise and individually for each of the PF motor 14 and the ASF motor 31. For example, for simplification of description, the resolution of the PF pulse signal (the rotational distance of the PF driving roller 4 per pulse of the PF pulse signal (that is, the transport amount of the printing paper P)) and the resolution of the ASF pulse signal (ASF) Assuming that the rotation distance of the rear paper feed roller 27 per pulse of the pulse signal (that is, the conveyance amount of the printing paper P) is the same, as shown in FIG. 7, the PF motor 14 and the ASF motor 31 are actually The target rotational speed at a constant speed when the motor is driven is set individually.

  Further, due to the characteristics of the PF motor 14 and the ASF motor 31, when the target rotational speed of the PF motor 14 and the ASF motor 31 at a constant speed is a predetermined rotational speed (that is, the PF driving roller 4 and the rear paper feeding roller 27). The minimum rotation distance of the PF motor 14 and the ASF motor 31 necessary for appropriately controlling the rotation of the PF motor 14 and the ASF motor 31 (when the target transport speed of the printing paper P in the constant speed region is a predetermined speed). (That is, the minimum transport amount of the print paper P by the PF drive roller 4 and the rear paper feed roller 27) is determined. For example, as shown in FIG. 7, if the minimum transport amount with respect to the target transport speed of the printing paper P in the constant speed region is determined and the target transport speed is 20 ips (inch per second), the intermittent transport of the printing paper P is performed. If the amount is not 100 pulses or more, the PF motor 14 and the ASF motor 31 cannot be appropriately controlled for rotation. In FIG. 7, for convenience of explanation, the relationship between the target rotational speed at the constant speed of the PF motor 14 and the minimum transport amount and the relationship between the target rotational speed at the constant speed of the ASF motor 31 and the minimum transport amount are shown. It is the same.

  As described above, the control command unit 59 of the present embodiment sets the intermittent transport amount of the printing paper P as the predetermined transport amount during the predetermined print control, and at the constant speed of the PF motor 14 and the ASF motor 31 during the intermittent transport. A control command for setting the rotational speed to a predetermined rotational speed is output to the control unit 50. Here, in this embodiment, the control command unit is more than the minimum conveyance amount at the constant speed (hereinafter referred to as the first command rotation number) of the PF motor 14 based on the control command output from the control command unit 59. 59, a control command for shortening the intermittent transport amount (hereinafter referred to as a command transport amount) of the printing paper P based on the control command output from 59, or a constant of the ASF motor 31 based on the control command output from the control command unit 59. There may be a case where a control command is output in which the command transport amount becomes shorter than the minimum transport amount at the rotation speed at the time of speed (hereinafter referred to as the second command rotation speed). For example, a control command in which the first command rotation speed and the second command rotation speed are 20 ips may be output from the control command section 59 even though the command transport amount is 50 pulses. In this case, based on the control command from the control command unit 59, the rotation of the PF motor 14 is controlled using the first command rotational speed as the target rotational speed, and the ASF motor 31 is rotated using the second command rotational speed as the target rotational speed. If the control is performed, the PF motor 14 and the ASF motor 31 cannot be properly controlled, and appropriate sync control cannot be performed.

  Therefore, in this embodiment, since the command transport amount is short (for example, the command transport amount is 50 pulses), the PF motor 14 is rotated with the first command rotation speed (for example, 20 ips) as the target rotation speed. Then, when the appropriate sync control cannot be performed and / or when the ASF motor 31 is rotated with the second command rotation speed (for example, 20 ips) as the target rotation speed, the appropriate sync control cannot be performed. Sometimes, even if a control command for outputting the first command rotation speed and the second command rotation speed as the target rotation speed is output from the control command section 59, the control section 50 performs appropriate sync control during the next intermittent conveyance. As is performed, the rotation of the PF motor 14 is controlled with a rotation speed lower than the first command rotation speed (for example, a transport speed of 10 ips) as a target rotation speed at a constant speed. In addition, lower rotational speed than the second command rotational speed (for example, the transport speed of 10Ips) rotating control ASF motor 31 as a target speed. That is, in this embodiment, the command transport amount is shorter than the minimum transport amount at the first command rotation speed and the second command rotation speed, and the PF motor 14 and the first command rotation speed and the second command rotation speed are set as the target rotation speed. When the rotation control of the ASF motor 31 cannot be performed, if the appropriate synchronization control cannot be performed, the target rotation speeds of the PF motor 14 and the ASF motor 31 are decreased together to perform the appropriate synchronization control.

  Further, as described above, the control command unit 59 of this embodiment may output only a control command for setting the intermittent transport amount of the printing paper P to a predetermined transport amount to the control unit 50. In the draft printing mode of this embodiment, in this case, the printing paper P is transported as fast as possible. For example, if the command transport amount is 100 pulses, the target rotational speed at the constant speed is set to the fastest 20 ips. Is done. That is, in the present embodiment, in the draft printing mode, when the control command unit 59 outputs only the control command related to the intermittent conveyance amount of the printing paper P to the control unit 50, the PF drive roller 4 and the rear paper feed roller 27 The PF motor 14 and the ASF motor 31 for conveying the printing paper P as fast as possible while controlling the rotation of the PF motor 14 and the ASF motor 31 appropriately, and the target rotational speed at the constant speed of the ASF motor 31 are set as the command conveyance amount. The control unit 50 selects based on the above. For example, if the command carry amount is 100 pulses, 20 ips is selected as the target rotation speed of the PF motor 14 and the ASF motor 31, and if the command carry amount is 50 pulses, the target rotation speed of the PF motor 14 and the ASF motor 31 is selected. Is selected as 10 ips.

  In this embodiment, when the control signal is not detected by the control unit 50 within at a predetermined time, even though the synchro control is performed, the output signal from at least one of the PF encoder 40 and the ASF encoder 41 is not detected. The control unit 50 stops the PF motor 14 and the ASF motor 31.

(Control flow for transport control of printing paper)
FIG. 8 is a flowchart showing a procedure for controlling the conveyance of the printing paper P shown in FIG. Hereinafter, a procedure for controlling the conveyance of the printing paper P during continuous printing in the draft printing mode will be described.

  When a control command for printing the printing paper P is input from the control command unit 59 to the control unit 50, the control unit 50 first receives an intermittent conveyance of the printing paper P from the control command unit 59. It is determined whether or not only the amount is related (step S1). When the control command relates to both the target rotation speed of the PF motor 14 and the ASF motor 31 and the intermittent conveyance amount of the printing paper P, the control unit 50 sets the first command rotation speed as the target rotation speed. Whether or not the PF motor 14 can be appropriately controlled for rotation, and whether or not the ASF motor 31 can be appropriately controlled for rotation with the second command rotational speed as the target rotational speed (that is, appropriate sync control is performed to determine whether the printing paper P Whether or not appropriate transport is possible) is determined (step S2). Specifically, it is determined whether the command transport amount is longer than the minimum transport amount at the first command rotational speed and the minimum transport amount at the second command rotational speed.

  When appropriate conveyance of the printing paper P is possible (specifically, when the command conveyance amount is longer than the minimum conveyance amount at the first command rotation number and the minimum conveyance amount at the second command rotation number), control is performed. The unit 50 sets the first command rotational speed as the target rotational speed of the PF motor 14 and sets the second command rotational speed as the target rotational speed of the ASF motor 31 (step S3). On the other hand, when the appropriate printing paper P cannot be transported (specifically, when the command transport amount is shorter than at least one of the minimum transport amount at the first command rotational speed and the minimum transport amount at the second command rotational speed). The control unit 50 sets a rotational speed lower than the first command rotational speed as the target rotational speed of the PF motor 14 and sets a rotational speed lower than the second command rotational speed as the target rotational speed of the ASF motor 31. Set (step S4).

  Thereafter, the control unit 50 controls the PF motor 14 and the ASF motor 31 according to the set target rotational speed, and intermittently conveys the printing paper P (step S5). Then, it is determined whether or not the printing on the printing paper P is completed by this intermittent conveyance (step S6). When printing on the printing paper P is finished, a paper discharge operation is performed, and printing control of the printing paper P, that is, conveyance control is finished. On the other hand, if printing on the printing paper P has not been completed, the process returns to step S1.

  In step S1, when the control command relates only to the intermittent conveyance amount of the printing paper P, the control unit 50 synchronizes the PF driving roller 4 and the rear paper feeding roller 27, and the PF motor 14 is synchronized. The target rotational speeds of the PF motor 14 and the ASF motor 31 for transporting the printing paper P as quickly as possible are selected and set based on the command transport amount while appropriately controlling the rotation of the ASF motor 31 (step). S7). When the target rotational speeds of the PF motor 14 and the ASF motor 31 are set, the process proceeds to step S5.

  In the present embodiment, step S5 is a transport step for intermittently transporting the printing paper P supplied from the paper feed hopper 26 in cooperation with the PF drive roller 4 and the rear paper feed roller 27. In step S4, if the PF motor 14 is rotationally controlled with the first command rotational speed as the target rotational speed, the appropriate rotational control of the PF motor 14 cannot be performed and / or the second command rotational speed is set as the target rotational speed. When the ASF motor 31 is rotated, when the appropriate rotation control of the ASF motor 31 cannot be performed, the first command rotation speed is set so that the PF motor 14 and the ASF motor 31 are appropriately controlled during the next intermittent conveyance. The lower rotation number is set as the target rotation number of the PF motor 14 at the next intermittent conveyance, and the rotation number lower than the second command rotation number is set as the target rotation number of the ASF motor 31 at the next intermittent conveyance. This is a number setting step. Further, in step S7, the target rotation speed of the PF motor 14 and the target rotation of the ASF motor 31 are controlled so that appropriate control of the PF motor 14 and the ASF motor 31 during the next intermittent transfer is performed based on the command transfer amount. This is a rotation speed selection step for selecting a number.

(Main effects of this form)
As described above, in this embodiment, during continuous printing in the draft printing mode, the peripheral speed of the rear paper feed roller 27 that conveys the printing paper P in cooperation with the PF drive roller 4 and the peripheral speed of the PF drive roller 4. Are controlled so that the rotation speeds of the PF motor 14 and the ASF motor 31 are substantially the same. Therefore, the PF drive roller 4 and the rear paper feed roller 27 can be rotated in synchronization, and the printing paper P supply operation can be performed without hindering the discharge operation and printing operation of the printing paper P. . That is, since the printing operation, the discharge operation, and the supply operation can be performed as a series of operations, the throughput can be further improved during continuous printing. Further, since the PF drive roller 4 and the rear paper feed roller 27 can be rotated in synchronization, the printing paper P can be appropriately conveyed between the PF drive roller 4 and the rear paper feed roller 27. As a result, it is possible to suppress generation of sound of the printing paper P that may occur during conveyance due to a change in tension applied to the printing paper P.

  Further, in this embodiment, when the control command output from the control command unit 59 relates to both the target rotation speed of the PF motor 14 and the ASF motor 31 and the intermittent conveyance amount of the printing paper P, When the rotation of the PF motor 14 is controlled with the one command rotation speed as the target rotation speed, the rotation of the PF motor 14 cannot be appropriately controlled and / or when the ASF motor 31 is rotated with the second command rotation speed as the target rotation speed. When the appropriate rotation control of the ASF motor 31 cannot be performed, the rotation speed lower than the first command rotation speed is set to the target rotation speed so that the PF motor 14 and the ASF motor 31 are appropriately controlled during the next intermittent conveyance. The PF motor 14 is rotationally controlled and the ASF motor 31 is rotationally controlled with a rotational speed lower than the second command rotational speed as a target rotational speed. For this reason, in the present embodiment, when the PF motor 14 is at the first command rotational speed or the ASF motor 31 is at the second command rotational speed and the rotation cannot be controlled appropriately, the first command rotational speed or the second command rotational speed is used. By setting the rotational speed lower than the number as the target rotational speed of the PF motor 14 or the ASF motor 31, the PF drive roller 4 and the rear paper feed roller 27 can be rotated in appropriate synchronization.

  Further, in the present embodiment, when the control command output from the control command unit 59 is only related to the intermittent conveyance amount of the printing paper P, the PF drive roller 4 and the rear paper feed roller are used during the next intermittent conveyance. 27, and commanding the target rotational speed of the PF motor 14 and the target rotational speed of the ASF motor 31 for conveying the printing paper P as fast as possible while appropriately controlling the rotation of the PF motor 14 and the ASF motor 31. Selection is based on the transport amount. Therefore, in this embodiment, the PF drive roller 4 and the rear paper feed roller 27 can be rotated in appropriate synchronization, and the printing paper P can be appropriately conveyed.

  In the present embodiment, when the control signal is not detected by the control unit 50 within a predetermined time, the control unit 50 does not detect an output signal from at least one of the PF encoder 40 and the ASF encoder 41, even though the synchronization control is performed. 50 stops the PF motor 14 and the ASF motor 31. When the control unit 50 cannot detect the output signals from the PF encoder 40 and the ASF encoder 41, an abnormal situation has occurred. With this configuration, it is possible to prevent clogging of the printing paper P and damage to the inside of the printer 1. .

(Other embodiments)
In the embodiment described above, when the PF motor 14 cannot be appropriately controlled with the first command rotational speed as the target rotational speed, or when the ASF motor 31 cannot be properly controlled with the second command rotational speed as the target rotational speed, The PF motor 14 is rotationally controlled with a rotational speed lower than the first command rotational speed as the target rotational speed, and the ASF motor 31 is rotated with the rotational speed lower than the second command rotational speed as the target rotational speed so that accurate sync control is performed. I have control. Alternatively, the PF drive roller 4 and the rear paper feed roller 27 are synchronized, and the target rotational speed of the PF motor 14 and the target rotational speed of the ASF motor 31 for appropriately controlling the rotation of the PF motor 14 and the ASF motor 31 are commanded. Selection is based on the transport amount. In addition, for example, in addition to these configurations, the first command rotation speed is set as the target rotation speed of the PF motor 14, the second command rotation speed is set as the target rotation speed of the ASF motor 31, and the PF motor 14 and the ASF motor 31 When the rotation control is performed, the actual rotation speed of at least one of the PF motor 14 and the ASF motor 31 is set to a predetermined value of the first command rotation speed or the second command rotation speed due to mechanical load fluctuation or disturbance. When the rotational speed of the ratio is not reached, the target rotational speed of the PF motor 14 and the ASF motor 31 may be reduced together to perform appropriate sync control. In addition, when at least one of the PF motor 14 and the ASF motor 31 is subject to heat generation restriction, the target rotation speed of the PF motor 14 and the ASF motor 31 may be decreased together to perform the synchro control.

  Note that the configuration of this embodiment can be applied to various apparatuses including a paper feed mechanism such as a laser printer in addition to an inkjet printer.

1 is a side view showing a schematic configuration of a main part of a printer according to an embodiment of the present invention. The figure which shows typically schematic structure of drive parts, such as PF drive roller of FIG. The figure for demonstrating operation | movement of the paper feed hopper of FIG. 1, and a retard roller. The block diagram which shows schematic structure of the control part of FIG. 2, and its peripheral device. The block diagram which shows typically a part of internal structure of the DC unit of FIG. The figure which shows the state in which the printing paper is conveyed at the time of the continuous printing in draft printing mode. 2 is a table showing a relationship between a conveyance speed and a minimum conveyance amount of a printing sheet in a constant speed region of the PF driving roller and the rear sheet feeding roller of FIG. FIG. 3 is a flowchart showing a procedure for transport control of the printing paper in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Printer, 4 PF drive roller (conveyance roller), 14 PF motor (conveyance motor), 26 Paper feed hopper (medium setting part), 27 Rear paper feed roller (supply roller), 31 ASF motor (supply motor), 40 PF Encoder (first encoder), 41 ASF encoder (second encoder), 50 control unit, 59 control command unit, P printing paper (print medium), S4 rotation speed setting step, S5 transport step, S7 rotation speed selection step.

Claims (5)

A transport roller capable of intermittently transporting the print medium supplied from a medium setting unit on which a print medium before printing is set, a transport motor for driving the transport roller, and supplying the print medium from the medium setting unit And a supply roller capable of intermittently conveying the print medium supplied from the medium setting unit in cooperation with the conveyance roller, a supply motor for driving the supply roller, and a peripheral speed of the conveyance roller. A controller that controls the rotation speed of the feed motor and the supply motor so that the peripheral speed of the supply roller is substantially the same;
When the control unit rotates the transport motor with the first command rotational speed of the transport motor based on the control command output from the control command unit that outputs a control command to the control unit as the target rotational speed, When the peripheral speed of the roller and the peripheral speed of the supply roller are not substantially the same and / or when the supply motor is rotated with the second command rotational speed of the supply motor based on the control command as a target rotational speed, When the peripheral speed of the transport roller and the peripheral speed of the supply roller are not substantially the same, the peripheral speed of the transport roller and the peripheral speed of the supply roller at the next intermittent transport are approximately the same. The conveyance motor is rotationally controlled with a rotational speed lower than the first command rotational speed as a target rotational speed, and the supply motor is rotated with a rotational speed lower than the second command rotational speed as a target rotational speed. Printer and controlling. A transport roller capable of intermittently transporting the print medium supplied from a medium setting unit on which a print medium before printing is set, a transport motor for driving the transport roller, and supplying the print medium from the medium setting unit And a supply roller capable of intermittently conveying the print medium supplied from the medium setting unit in cooperation with the conveyance roller, a supply motor for driving the supply roller, and a peripheral speed of the conveyance roller. A controller that controls the rotation speed of the feed motor and the supply motor so that the peripheral speed of the supply roller is substantially the same;
The control unit outputs the peripheral speed of the transport roller during the next intermittent transport based on the command transport amount of the print medium based on the control command output from the control command unit that outputs a control command to the control unit. A printer, wherein a target rotational speed of the transport motor and a target rotational speed of the supply motor are selected so that a peripheral speed of the supply roller is substantially the same. A first encoder connected to the control unit and capable of detecting the rotational speed of the transport motor; and a second encoder connected to the control unit and capable of detecting the rotational speed of the supply motor;
The said control part stops the said conveyance motor and the said supply motor, when the output signal from at least any one of the said 1st encoder and the said 2nd encoder cannot be detected. Printer. Driven by a transport motor and transported by a transport roller for transporting the print medium supplied from a medium set unit on which a print medium before printing is set, and supplied by a supply motor to supply the print medium from the medium set unit A conveying step of rotating the roller at substantially the same peripheral speed, and intermittently conveying the print medium supplied from the medium setting unit in cooperation with the conveying roller and the supply roller;
When the conveyance motor is rotated with the first command rotation number of the conveyance motor based on the control command output from the control command unit as the target rotation number, the circumferential speed of the conveyance roller and the circumferential speed of the supply roller are substantially the same. And / or when the supply motor is rotated with the second command rotational speed of the supply motor based on the control command as a target rotational speed, the peripheral speed of the transport roller and the peripheral speed of the supply roller are When not substantially the same, the rotational speed lower than the first command rotational speed is set to a target of the transport motor so that the peripheral speed of the transport roller and the peripheral speed of the supply roller in the transport step are substantially the same. And a rotation speed setting step for setting a rotation speed lower than the second command rotation speed as a target rotation speed of the supply motor. Control method of. Driven by a transport motor and transported by a transport roller for transporting the print medium supplied from a medium set unit on which a print medium before printing is set, and supplied by a supply motor to supply the print medium from the medium set unit A conveying step of rotating the roller at substantially the same peripheral speed, and intermittently conveying the print medium supplied from the medium setting unit in cooperation with the conveying roller and the supply roller;
Based on the command conveyance amount of the print medium based on the control command output from the control command unit, the circumferential speed of the conveyance roller and the circumferential speed of the supply roller in the conveyance step are substantially the same. A printer control method comprising: a rotation speed selection step of selecting a target rotation speed of the transport motor and a target rotation speed of the supply motor.

Images