JP6349848B2 - FEEDING DEVICE AND ELECTRONIC DEVICE HAVING FEEDING DEVICE - Google Patents

Description

  The present invention relates to a feeding device that drives a feeding mechanism capable of feeding a medium such as paper with a motor, and an electronic apparatus including the feeding device.

  A printing apparatus is known as an electronic apparatus provided with this type of feeding apparatus (for example, Patent Document 1). When the load of the motor that is the power source of the feeding device is large, if the power consumption exceeds the allowable limit of the power supplied by the power source and the power becomes insufficient, if the control is continued as it is, the system goes down. For this reason, when the load of the motor becomes large and a voltage drop is detected, the drive of the motor is stopped to prevent the system from going down.

  For example, in Patent Document 1, assuming that a skew (skew) in which a print medium such as paper is fed obliquely occurs, printing that performs a skew removing operation by an operation of a feeding mechanism during feeding is performed. An apparatus is disclosed. In this printing apparatus, the skew removal method is changed according to the type of print medium (for example, paper type).

JP 2004-331255 A

  By the way, even when skew removal operation with relatively large power consumption of the motor is performed on a print medium of a type having a relatively small load during feeding, the power consumption of the motor is sufficiently less than the power supply power. . On the other hand, if a skew removal operation with a relatively large motor power consumption is performed on a print medium with a relatively large load during feeding, the motor power consumption will exceed the power supply power supply. There is a risk of system down. For this reason, a skew removal operation in which the power consumption of the motor is relatively small is set for a type of print medium having a relatively large load during feeding.

  In the printing apparatus described in Patent Literature 1, for example, a setting input error input by the user by mistakenly entering the type of printing medium such as paper, or setting the printing medium in a paper feed tray or paper cassette by mistakenly entering the type of printing medium. If the set mistake is made, the type of the print medium actually set differs from the set type of the print medium. For example, when a relatively heavy load type print medium such as cardboard or photo paper is loaded, the user inputs and sets the type of print medium with a relatively small load (for example, “plain paper”). Can happen.

  In this case, the skew removal operation is performed by a skew removal method that is used for a print medium of a relatively small load and has a relatively large power consumption of the motor. At this time, a skew removing operation for a type of printing medium with a small load is performed on a printing medium with a large load such as thick paper or special paper (photo paper) actually set. For this reason, in order to feed the sheet at the set speed, an excessive current flows through the motor, and its power consumption becomes larger than the power supplied by the power source, resulting in a voltage drop. In order to avoid a system down due to this type of voltage drop, the motor is normally stopped based on the detection of the voltage drop. However, if the user performs a print execution operation on the printing device again by setting the same type of print medium again, a voltage drop is detected in the same way when the same skew removal operation is performed during paper feeding, and the motor Is forcibly stopped. As a result, there has been a problem that the paper feeding failure is repeated no matter how many times printing is performed.

  The above-mentioned problem is similarly applied to a feeding device that feeds a document as an example of a medium onto a reading surface of a document table in a scanner device (image reading device), for example, as well as a feeding device in a printing apparatus. is there.

  The present invention has been made in order to solve the above-described problems. The object of the present invention is the frequency with which a failure is repeated even if the feeding of the medium is repeated after the failure when the feeding of the medium due to a voltage drop fails. It is an object to provide a feeding device that can reduce the power consumption and an electronic device equipped with the feeding device.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A feeding device that solves the above-described problem includes a feeding mechanism that feeds a medium, a motor that is a power source that drives the feeding mechanism, and a control unit that drives and controls the motor. When the voltage drop of the supply voltage of the power supply unit that supplies power to the motor is detected during the driving of the motor that feeds the medium in the first mode, the driving of the motor is stopped, and the motor is driven more than in the first mode. By changing to the second mode that requires less power and driving the motor, the feeding of the medium is retried.

  According to this configuration, when a voltage drop in the supply voltage of the power supply unit is detected during driving of the motor that feeds the medium in the first mode, the driving of the motor is stopped. As a result, the medium feeding in the first mode fails, but the system down can be avoided. After the motor is stopped, the feeding of the medium is retried by driving the motor in the second mode which requires less power than the first mode. Since the medium feeding in the second mode requires less power than the first mode, the voltage supplied from the power source to the motor is unlikely to drop. Therefore, even if the feeding of the medium is performed again, the frequency of repeated feeding failures can be reduced.

  In the feeding device, the first and second modes are modes that define a skew removing operation that removes a skew in which the medium is inclined with respect to a feeding direction performed during feeding of the medium, and the control unit includes: Changing the first mode including the first skew removing operation during the feeding of the medium to the second mode including the second skew removing operation which requires less power than the first skew removing operation. preferable.

A feeding device that solves the above-described problem includes a feeding mechanism that feeds a medium, a motor that is a power source that drives the feeding mechanism, and a control unit that drives and controls the motor. When a voltage drop in the supply voltage of the power supply unit due to an overcurrent of the motor is detected during driving of the motor that feeds the medium in the first mode including the first skew removing operation during feeding, The drive is stopped, the second skew removal operation that requires less power than the first mode is changed to the second mode including the medium feeding, and the motor is driven to retry the feeding of the medium. .
According to this configuration, even when the voltage drop is detected in the first skew removal operation performed during the medium feeding in the first mode and the motor driving is stopped, the drive speed is lower than that in the first skew removal operation. The operation is changed to the second skew removal operation that requires electric power, and the feeding of the medium is retried in the second mode. Therefore, the frequency with which the failure of feeding the medium due to the voltage drop is repeated can be reduced.

  The feeding device includes a plurality of the motors, and the control unit drives the plurality of motors in the first skew removal operation, and in the second skew removal operation, more than in the first skew removal operation. It is preferable to drive a small number of motors.

  According to this configuration, even if a voltage drop is detected in the first skew removal operation in which a plurality of motors are driven and the feeding of the medium fails, a smaller number of motors are driven than in the first skew removal operation. The second mode including the second skew removing operation is changed. Therefore, the frequency with which the failure of feeding the medium due to the voltage drop is repeated can be reduced.

  In the feeding device, the first and second modes are speed modes that define a driving speed of the motor during the feeding, and the control unit is a slower speed mode than the first mode. It is preferable to change to the second mode.

  According to this configuration, when the voltage drop is detected, the first mode, which is the speed mode that defines the driving speed of the motor during feeding, is changed to the second mode, which is a slower speed mode. A voltage drop is less likely to occur during the feeding of the medium in the two modes, and the frequency with which the failure of feeding the medium due to the voltage drop is repeated can be reduced.

  In the feeding device, when the control unit is changed from the first mode to the second mode, it is preferable that the control unit maintains the second mode until the job when changing to the second mode is completed. .

  According to this configuration, the second mode is maintained until the job when the first mode is changed to the second mode is completed, so that it is possible to avoid failure in feeding subsequent media in the same job. Therefore, it is possible to avoid a decrease in throughput due to the retry of the medium feeding for each medium during the same job.

  The feeding device includes a first sensor that detects the medium in the middle of the feeding path, and the control unit stops driving the motor during feeding of the medium in the first mode. If the first sensor does not detect the medium, the feeding is retried without discharging the medium. If the first sensor detects the medium, the next medium is discharged after the medium is discharged. It is preferable to retry sending.

  According to this configuration, when the driving of the motor is stopped during the feeding of the medium in the first mode, if the first sensor does not detect the medium, the feeding is retried without discharging the medium. On the other hand, if the first sensor detects the medium, the feeding of the next medium is retried after the medium is ejected. For this reason, it is possible to detect the medium for which the feeding has been retried by the first sensor, and to feed the medium to the target position with high positional accuracy in feeding in the second mode with reference to the position detected by the first sensor. can do.

  The feeding device includes a placement unit on which the medium is set, and a second sensor that detects the presence or absence of the medium set on the placement unit, and the control unit includes the first sensor that receives the medium. When it is detected and the medium is discharged, it is preferable to start retrying feeding of the medium set on the mounting portion upon detection of the medium by the second sensor.

  According to this configuration, if the feeding of the medium in the first mode fails, the medium is fed in the second mode if the succeeding medium has been set on the placement unit and the second sensor is in the detection state. On the other hand, if the medium is not set on the loading unit when the retry is started, when the user sets the medium on the loading unit and the second sensor detects it, the medium is fed in the second mode. Retry is started. For this reason, when the feeding of the medium in the first mode fails, the feeding of the medium in the second mode is started, so that the user does not need to issue a printing instruction again.

  The feeding device further includes a power supply device capable of switching the power supply between an AC power supply unit that converts an alternating current fed through a plug inserted into a commercial power outlet into a direct current and outputs the direct current, and a battery. Preferably it is.

  According to this configuration, even if the voltage drop is detected because the power source is switched from the AC power source unit to the battery due to the plug being pulled out from the outlet, and the driving of the motor in the first mode is stopped, Feeding is retried in 2 modes. Therefore, it is possible to prevent the system from being down when the plug is pulled out from the outlet, and to reduce the frequency of repeated feeding failures.

  In the feeding device, the control unit detects a voltage drop by monitoring a voltage at a position on a power supply line between a confluence of outputs of the AC power supply unit and the battery and a drive circuit of the motor. Is preferred.

According to this configuration, even if the power source is switched between the AC power supply unit and the battery and power is supplied to the motor, only one voltage monitoring point for detecting a voltage drop is required.
In the feeding device, when the voltage drop is detected during feeding of the medium, the driving of the motor is stopped, and the first mode when the voltage drop is detected requires the first power to be lower. It is preferable that the control by the control unit to change to the two mode and retry the feeding of the medium is performed when the motor is driven by battery power.

  According to this configuration, a voltage drop is likely to occur during feeding of a medium that uses a battery with a relatively small power supply as a power source. When the motor is driven with such battery power, Even if the feeding of the medium fails, since the feeding of the medium is retried in the second mode, the frequency of repeated feeding failures can be reduced.

  An electronic device that solves the above problem includes the feeding device. According to this structure, the same effect as the said feeder can be acquired with an electronic device.

1 is a perspective view illustrating a printer according to an embodiment. FIG. 2 is a schematic perspective view showing the printer in a state where an exterior cover is removed. (A)-(c) is a schematic side view explaining operation | movement of an automatic feeding apparatus. (A) is a schematic side view for explaining a skew-removing operation of the reverse rotation butting method, (b) is also a schematic plan view, and (c) is a schematic side view for explaining a cueing operation for conveying a sheet to a printing start position, (D) is a schematic plan view. (A), (c) is a schematic side view explaining the skew removal operation | movement of a biting discharge system, (b), (d) is each schematic plan view. FIG. 3 is a block diagram illustrating an electrical configuration of the printer. The block diagram which shows the circuit structure of the power supply device which supplies each electric power of an AC adapter and a battery to a motor drive circuit. The block diagram which shows the function structure of a computer. The graph which shows the relationship between a motor speed profile and rotation speed, and an electric current value. A control table is shown, (a) is an acceleration table, (b) is a schematic diagram of a deceleration table, respectively. The graph which shows the relationship between the rotational speed of each motor and the electric current value in the feed operation in the 1st feed mode with the 1st skew removal operation | movement of reverse rotation abutting method. The graph which shows the relationship between the rotational speed of each motor and the electric current value in the feed operation in the 2nd feed mode with the 2nd skew removal operation | movement of a biting discharge system. The graph which shows the detection voltage at the time of detecting a voltage drop. The flowchart which shows feeding control.

Hereinafter, an embodiment of a printer including a feeding device will be described with reference to the drawings.
As shown in FIG. 1, a printer 11 as an example of an electronic device is a mobile inkjet color printer as an example, and includes a device body 12 having a thin, substantially rectangular parallelepiped shape. On the front surface (right surface in FIG. 1) of the apparatus main body 12, an operation panel 13 used for user input operations and the like is provided. The operation panel 13 is provided with a display unit 14 made of, for example, a liquid crystal panel and an operation unit 15 made up of a plurality of operation switches. The operation unit 15 includes a power switch 15 a, a selection switch 15 b and a cancel switch 15 c that are operated when a desired selection item is selected on the menu screen of the display unit 14. Note that at least a part of the operation panel 13 may be provided on the upper surface of the apparatus main body 12 in order to reduce the thickness thereof, or may be a storage type or a folding type that can be stored in the apparatus main body 12 when not in use. Further, the display unit 14 may be an external system that is connected to the apparatus main body 12 via a connector.

  As shown in FIG. 1, the printer 11 is an example of a medium that is set in a state of being positioned in the width direction by a pair of edge guides 16 a on a feeding tray 16 that extends to the back side of the apparatus main body 12. An automatic feeding device 17 is provided as an example of a feeding device capable of feeding sheets P one by one into the apparatus main body 12. The automatic feeding device 17 is not limited to the feeding method provided with this type of feeding tray 16, and the paper is set one by one from the paper group set in the feeding cassette that is detachably attached to the main body 12. May be a cassette feeding method.

  As shown in FIG. 1, a carriage 21 is provided in the apparatus main body 12 so as to be reciprocally movable in the scanning direction X while being guided by a guide shaft 22. A recording head 23 capable of ejecting ink droplets onto the paper P fed from the automatic feeding device 17 is attached to the lower portion of the carriage 21. The paper P being printed is intermittently conveyed in the conveyance direction Y intersecting the scanning direction X, and ink is ejected from the recording head 23 in the process of moving the carriage 21 in the scanning direction X between each conveyance. Thus, a document or an image is printed on the paper P. The printed paper P discharged from the discharge port 12a on the front surface of the apparatus main body 12 is stacked on a slide-type discharge stacker 24 (discharge tray) that has been extended.

  In addition, a USB port 25, a card slot 26, and a wireless LAN interface (not shown) (for example, “Wi-Fi” (registered trademark)) are provided at the front side end of the apparatus main body 12 (right end as an example in FIG. 1). Is provided. Image data or the like is read from an external storage device (for example, a USB memory) connected to the USB port 25 or a memory card connected to the card slot 26, or a portable host device (for example, a smartphone or a cellular phone) via a wireless LAN interface. ) Can be received wirelessly, and the printer 11 can print the image or the like.

  Further, the apparatus main body 12 has a power jack (not shown) that can be connected to a power supply plug on the output side of the AC adapter 27 having a power plug 27a that can be plugged into an outlet of the commercial power supply 30 (see FIG. 3). Z). The AC adapter 27 supplies power to the printer 11 with a predetermined voltage obtained by converting alternating current from the commercial power supply 30 into direct current. Further, a battery 28 is accommodated in the apparatus main body 12 as a power source that can be used when the printer 11 is carried. The battery 28 of the present embodiment is a small battery with a relatively small capacity in order to reduce the size of the printer. For this reason, the power Wb (battery supply power) that can be supplied by the battery 28 is smaller than the power Wac (AC power supply power) that can be supplied via the AC adapter 27 (Wb <Wac). Of course, although the battery 28 is a little larger, the battery supply power Wb having the same value as the AC power supply power Wac by the AC adapter 27 may be output.

  Next, the internal configuration of the printer 11 will be described with reference to FIG. As shown in FIG. 2, in the printer 11, the carriage 21 is placed in the scanning direction X on the guide shaft 22 installed between the left and right side walls in FIG. Are provided so as to be capable of reciprocating. An endless timing belt 34 is wound around a pair of pulleys 33 attached to the inner surface of the back plate of the main body frame 31, and the carriage 21 is fixed to a part of the timing belt 34. The pulley 33 on the right side in FIG. 2 is connected to the drive shaft (output shaft) of the carriage motor 35, and the carriage 21 scans via a timing belt 34 that rotates forward or backward as the carriage motor 35 is driven forward or backward. Reciprocate in direction X.

  A plurality of (for example, four) ink cartridges 37 each containing four color inks of black (K), cyan (C), magenta (M), and yellow (Y), for example, are loaded on the carriage 21. Has been. The ink supplied from each ink cartridge 37 is ejected from a nozzle group for each ink color that opens on the lower surface of the recording head 23. Further, below the movement path of the carriage 21, a support base 38 that defines an interval (gap) between the recording head 23 and the paper P is provided so as to extend along the scanning direction X. The ink colors that can be ejected by the recording head 23 are not limited to four colors, and may be three colors, five to eight colors, or one black color.

  The main body frame 31 is provided with a linear encoder 39 that outputs a number of pulses proportional to the amount of movement of the carriage 21 so as to extend along the movement path of the carriage 21. In the printer 11, position control and speed control of the carriage 21 and control of ink ejection timing of the recording head 23 are performed based on the pulse signal output from the linear encoder 39.

  A feeding motor 41 provided at the lower right end of the main body frame 31 in FIG. 2 feeds a plurality of sheets P set on the feeding tray 16 (see FIG. 1) one by one. (See FIG. 3). The transport motor 42 drives a transport roller pair 43 and a discharge roller pair 44 provided on the upstream side and the downstream side of the support base 38 in the transport direction Y, respectively. Each of the roller pairs 43 and 44 includes drive rollers 43a and 44a that are rotated by the power of the transport motor 42, and driven rollers 43b and 44b that are brought into contact with the drive rollers 43a and 44a and rotated. The paper P is transported in the transport direction Y while being sandwiched (niped) at two locations by the roller pairs 43 and 44 that are rotated by the power of the transport motor 42. In the present embodiment, an example of a feeding mechanism is configured by the feeding roller 20 and the feeding roller pair 43 that feed the paper P set on the feeding tray 16 to the printing start position. An example of the motor is configured by the feed motor 41 and the transport motor 42 that are power sources of the feed roller 20 and the transport roller pair 43 that constitute an example of the feed mechanism. That is, this embodiment is an example in which a plurality of (two in this example) motors that are power sources of the feeding mechanism are provided.

  In the serial printer 11, a printing operation in which ink is ejected from the nozzles of the recording head 23 onto the paper P while the carriage 21 is reciprocated in the scanning direction X, and the transport amount of the paper P in the transport direction Y to the next recording position. A document, an image, or the like is printed on the paper P by alternately repeating the feeding operation for conveying only the paper. In the present embodiment, the feed motor 41 and the feed motor 42 constitute an example of the first motor. Thus, this embodiment is an example in which two first motors are provided. The carriage motor 35 constitutes an example of a second motor.

  In FIG. 2, one end position (right end position in FIG. 2) on the movement path of the carriage 21 is a home position (home position) where the carriage 21 stands by when not printing. A maintenance device 45 that performs maintenance of the recording head 23 is disposed immediately below the carriage 21 disposed at the home position. Note that the transport motor 42 of this embodiment is also a power source of the maintenance device 45.

  As shown in FIG. 3, a hopper 18 is supported on the upper surface side of the feeding tray 16 disposed obliquely on the back surface of the main body so as to be tiltable within a predetermined angle range about an upper end shaft 18a. Yes. The hopper 18 is urged in a direction away from the feed tray 16 (upper left direction in FIG. 3) by a compression spring 19 interposed between the hopper 18 and the feed tray 16. Near the lower end of the hopper 18, a feeding roller 20 is supported so as to be rotatable about a rotation shaft 20 a. The hopper 18 has a retracted position shown in FIG. 3A where the set paper P is separated from the feeding roller 20, and FIGS. 3B and 3C where the set paper P can contact the feeding roller 20. It reciprocates between the feeding positions shown in (1).

  A guide portion 16b for guiding the paper when the feeding roller 20 feeds is provided at a position facing the feeding roller 20 on the upper surface of the end of the feeding tray 16 on the downstream side in the paper feeding direction (left side in FIG. 3). It has been. Further, a retard roller 46 is disposed at a position facing the feed roller 20 in the vicinity of the guide portion 16b. The retard roller 46 is provided so as to be driven and rotated with respect to the feeding roller 20 in a state where a constant rotational load is applied by a torque limiting mechanism such as a torque limiter. The hopper 18 and the retard roller 46 operate in conjunction with each other. When the hopper 18 is disposed at the feeding position shown in FIG. 3B, the fed paper P is fed between the feeding roller 20 and the retard roller 46. Sandwiched between. The automatic feeding device 17 is provided with a paper presence sensor 47 which is an example of a second sensor for detecting the presence or absence of the paper P on the hopper 18.

  When the feeding roller 20 in a state where the hopper 18 is moved up to the feeding position and the paper P is in contact with the paper P rotates in the clockwise direction in FIG. 3, only the topmost paper P is retarded with the feeding roller 20. The paper is fed while being sandwiched between the rollers 46. In this feeding process, the uppermost sheet P is separated from other sheets by the retard roller 46.

  As shown in FIG. 3, a paper detection sensor that is an example of a first sensor that can detect the paper P that is fed along the paper conveyance path at a position between the feeding roller 20 and the conveyance roller pair 43. 48 is provided. The paper detection sensor 48 includes a lever 48a whose lower end extends to reach the paper conveyance path, and an optical sensor unit 48b whose detection target is the upper end of the lever 48a. In the state where there is no paper P to be detected in the detection area, the paper detection sensor 48 returns to the original position shown in FIGS. 3A and 3B by the biasing force of a spring (not shown) and is turned off. When the leading edge of the fed paper P pushes the lower end of the lever 48a and tilts it as shown in FIG. In the printer 11, the position of the paper P in the transport direction Y is managed based on the paper position when the paper detection sensor 48 detects the leading edge of the paper P and is turned on (for example, the origin). The paper P whose position is controlled is fed until the leading end reaches a printing start position where printing by the recording head 23 is started, and the paper P is inclined with respect to the transport path in the course of the feeding process. A skew removing operation, which will be described later, is performed to remove the skew (skew) that tilts.

  A paper width sensor 49 is provided in the carriage 21 at a position upstream of the recording head 23 in the transport direction Y. The paper width sensor 49 is an optical sensor that can move together with the carriage 21, and can detect the side edge of the fed paper P in the scanning direction X (width direction) when the carriage 21 moves in the scanning direction X. In addition, the leading edge of the paper P can be detected by waiting for the paper P to be fed in a state where the carriage 21 is positioned within the conveyance path width of the paper P. Note that the retard roller 46 and the hopper 18 are shown in FIGS. 3B and 3C as long as there is a next page to be fed after the cueing of feeding the sheet P to the printing start position is completed. ) And is returned to the retracted position when there is no next page to be fed.

  Next, a skew removing operation performed in the middle of the feeding process in order to remove skew (skew) in which the sheet P is inclined with respect to the conveyance path will be described. There are mainly two types of skew removal operations: a “reverse rotation butting operation” and a “biting and discharging operation”. The sheet feeding mode includes a first feeding mode in which a “reverse rotation abutment operation” is performed as an example of a first skew removal operation during feeding, and an example of a second skew removal operation during feeding. There are a second feeding mode in which the “biting and discharging operation” is performed and a third feeding mode in which the skew removal operation is not included during feeding.

  In addition to the first to third feeding modes, a speed mode that defines the driving speed of the motors 41 and 42 in the feeding process is prepared. For example, three types of speed modes are prepared: a high speed mode, a medium speed mode, and a low speed mode. For example, the speed mode is determined by the power supply mode and the type of medium. The high-speed mode is set in the case of the first medium type having a relatively small load, including the AC power mode and the medium type including a plain paper and a paper type similar to the plain paper. Here, the first medium type refers to a medium type whose load on the feeding mechanism is as small as that of plain paper. In the battery mode and the medium type is the first medium type, the medium speed mode is set. Further, in the case of the AC medium mode or the battery mode and the medium type is the second medium type having a relatively large load including the special paper and the paper type corresponding to the special paper, the low speed mode is set. Here, the second medium type refers to a medium type whose load on the feeding mechanism is as large as that of the dedicated paper.

  The first speed U1 set to the high speed mode is a value within a range of 5 to 20 ipc (inch per second) as an example. The second speed U2 set in the medium speed mode is a value within a range of 3 to 30 ipc as an example. Further, the third speed U3 in which the low speed mode is set is a value within the range of 1 to 5 ipc as an example. However, the first to third speeds U1 to U3 have a relationship of U1> U2> U3. The number of speed types in the speed mode can be changed as appropriate, and may be two, four, five, or more in addition to the three. Also, the method of determining the speed is not limited to being defined according to the power supply mode and the medium type. For example, the speed may be defined according to the power supply mode, or the speed may be defined according to the medium type. In this case, a lower speed is set in the battery mode than in the AC power mode. In addition, a lower speed is set for the second medium type than for the first medium type.

  Hereinafter, with reference to FIG. 4 and FIG. 5, these skew removal operations will be described in order. First, the feeding operation in the first feeding mode including the reverse rotation abutting operation will be described with reference to FIG. The feeding operation accompanied by the reverse rotation abutting operation includes a skew removing operation shown in FIGS. 4A and 4B and a cueing operation shown in FIGS. 4C and 4D.

  As shown in FIGS. 4A and 4B, the paper P is fed by rotating the feed motor 41 in the normal rotation direction, which is the paper feed direction, and rotating the feed roller 20 in the normal rotation direction. Feed along the route. Before the leading edge of the paper P reaches the transport roller pair 43, the transport motor 42 is driven in reverse so that the transport roller pair 43 is rotated in a direction opposite to the direction during transport of the paper P. As a result, as shown in FIGS. 4A and 4B, the leading end of the sheet P in the transport direction is abutted against the reversely rotating transport roller pair 43, and the leading end side is in the axial direction of the transport roller pair 43. By being parallel, the skew in which the paper P is inclined with respect to the transport direction Y is eliminated. That is, as shown in FIG. 4B, the skewed paper P is abutted against a pair of conveying rollers 43 whose front corners rotate in reverse, and the paper P is a solid line arrow with the corners abutted as fulcrums. Is rotated to a position indicated by a two-dot chain line in the drawing, and the skew of the paper P is removed.

  In this reverse abutting operation, the sheet P rotates around the corner from the corner of the leading edge of the sheet P skewed with the assumed maximum skew amount against the conveying roller pair 43. This is performed only for a predetermined rotation amount obtained by adding a slight margin to the rotation amount of the feeding roller 20 necessary for eliminating the skew of the maximum skew amount. Note that the reverse butting operation is employed when the paper P is relatively thick and hard, such as special paper (photo paper, etc.), or when the printing mode requires high-speed feeding operation of the paper P. Is preferred.

  When the reverse rotation abutting operation is completed, the rotation direction of the conveyance motor 42 is switched from reverse rotation to normal rotation, and as shown in FIGS. Is rotated in the forward direction. By switching the rotation direction, the skew removing operation is switched to the cueing operation, and the paper P from which the skew is removed by this cueing operation is fed to the printing start position.

  Next, the biting discharge operation of the second skew removal operation will be described with reference to FIG. The feeding operation of the biting and discharging method includes three operations including a biting operation, a discharging operation, and a cueing operation.

  As shown in FIGS. 5A and 5B, the feeding motor 41 and the conveying motor 42 are rotated in the normal rotation direction, which is the sheet feeding direction, so that the feeding roller 20 and the conveying roller pair 43 are rotated in the normal rotation direction. By rotating, the paper P is fed along the feeding path. After the leading edge of the paper P reaches the transport roller pair 43 and is sandwiched between them, the paper P is further transported, and the leading edge of the paper P is a predetermined amount on the downstream side in the transport direction Y with respect to the transport roller pair 43. When reaching the position protruding by (amount), the driving of the feeding motor 41 and the conveying motor 42 is stopped.

  Next, as shown in FIGS. 5C and 5D, the feeding motor 41 is driven in the reverse direction while the feeding motor 41 is stopped. As a result, the transport roller pair 43 rotates in the direction opposite to the direction during transport of the paper P while the feeding roller 20 is stopped, and the leading end of the paper P is upstream of the transport roller pair 43 in the transport direction. Vomited to the side. Since this discharging operation is performed under the stopped state of the feeding roller 20, the sheet P is downstream in the transport direction from the portion pressed by the feeding roller 20, as shown in FIGS. It will bend in the side part. Then, the sheet P is rotated by the force of the bent sheet P to return to the original, and the skew with respect to the transport direction Y of the sheet P is eliminated.

  When the discharge operation is completed, the transport motor 42 is switched to drive in the forward direction, and the drive in the forward direction of the feeding motor 41 is resumed, as in FIGS. 4C and 4D. The cueing operation is started by the forward rotation of the feeding roller 20 and the forward rotation of the transport roller pair 43, and the paper P from which the skew has been removed is transported to the printing start position.

  Next, the electrical configuration of the printer 11 will be described with reference to FIG. As shown in FIG. 6, the controller 50 provided in the printer 11 includes a power supply device 51, a computer 52 (microcomputer), a display drive circuit 53, a head drive circuit 54, and motor drive circuits 55 to 57. The computer 52 is connected with an operation unit 15, a paper presence / absence sensor 47, a paper detection sensor 48, a paper width sensor 49, a linear encoder 39 and encoders 58 and 59 as input systems. The computer 52 is connected with a display drive circuit 53, a head drive circuit 54, and motor drive circuits 55 to 57 as an output system. A display unit 14, a recording head 23, a carriage motor 35, a feed motor 41, and a transport motor 42 are connected to the drive circuits 53 to 57, respectively.

  The power supply device 51 shown in FIG. 6 inputs a direct current of a predetermined voltage (primary voltage) obtained by transforming or rectifying the alternating current voltage from the commercial power supply 30 through the AC adapter 27, and the input direct current is supplied to the motors 35, 41, The voltage is boosted to a predetermined voltage required for driving 42. Then, the power supply device 51 supplies the boosted predetermined voltage to the motors 35, 41, and 42 through the motor drive circuits 55 to 57 in one system, and steps down to a plurality of types of predetermined voltages in the other system. A predetermined voltage required for the recording head 23, the display unit 14, the computer 52, and the input system is supplied.

  Further, the battery 28 accommodated in the apparatus main body 12 is electrically connected to the power supply device 51. The computer 52 has a function of detecting the voltage at a predetermined location in the power supply device 51 and detecting the connection of the AC adapter 27 and the connection of the battery 28 based on the detected voltage. For this reason, the computer 52 can recognize whether the power source of the power supply at that time is the AC adapter 27 (that is, the commercial power source 30) or the battery 28. The computer 52 sets the power mode to “AC power mode” when the connection of the AC adapter 27 is detected, and sets the power mode when the connection of the AC adapter 27 is not detected and the connection of the battery 28 is detected. “Battery mode”.

  The power supplied from the battery 28 is smaller than the power supplied via the AC adapter 27. For this reason, the supply power of the power supply (battery 28) in the battery mode is smaller than the supply power of the power supply (AC adapter 27) in the AC power supply mode. In the battery mode, for example, if the power consumption of each of the motors 41 and 42 increases and the power consumption of the printer 11 exceeds the power supply of the battery 28, the power supply voltage may drop, leading to a system down or the like. is there. Therefore, when the computer 52 of the present embodiment detects a drop in the supply voltage of the power source (hereinafter also referred to as “voltage drop”) when the power consumption of the printer 11 exceeds the supply power of the battery 28, the motor 35, Control to reduce the total power consumption of 41 and 42 is performed. In the present embodiment, the AC adapter 27 that converts alternating current input from the commercial power supply 30 into direct current corresponds to an example of an AC power supply unit. The AC power supply unit and the battery 28 constitute an example of the power supply unit.

  In addition, when the power consumption of the printer 11 exceeds the supply power of the power supply unit during the feeding operation for feeding the paper P to the printing start position, the computer 52 detects a voltage drop of the power supply. By stopping the drive of any one of 41 and 42 that is currently being driven, system down is prevented.

  When the computer 52 outputs the command values to the motor drive circuits 55 to 57, drive voltages corresponding to the command values are applied to the motors 35, 41, and 42. In this example, for example, a PWM (pulse width modulation) signal is output as a command value, and a current according to the duty ratio of the PWM signal (ratio of the pulse width to the period of the PWM signal) flows through each of the motors 35, 41, 42. . The computer 52 drives and controls the motors 35, 41, and 42 by individually outputting command values to the motor drive circuits 55 to 57, respectively. The computer 52 controls the speed of the motors 35, 41, and 42 according to the command value, and cuts off the current to the corresponding motor among the motors 35, 41, and 42, for example, by setting the command value to “0” (zero). It is possible. Further, the carriage motor 35 rotates forward or backward according to a direction instruction signal output from the computer 52 to the motor drive circuit 55.

  A paper presence sensor 47 shown in FIG. 6 is an optical or contact sensor that can detect the presence or absence of the paper P on the feeding tray 16 (see FIG. 3). In addition, the paper detection sensor 48 detects the leading edge of the paper P at a predetermined position on the feeding path, and the position when the leading edge is detected measures the position (transport position) in the transport direction Y of the paper P. Used for the reference position. Further, the paper width sensor 49 is a reflective optical sensor that can detect the side edge of the paper P by moving in the scanning direction X together with the carriage 21 while irradiating the detection light toward the paper P on the support base 38. Based on the detection signal of the paper width sensor 49, the width of the paper P or the print start position (ink ejection start position) in the scanning direction X of the recording head 23 is obtained.

  The linear encoder 39 outputs a pulse signal having a number of pulses proportional to the amount of rotation of the carriage motor 35. The encoder 58 outputs a pulse signal having a number of pulses proportional to the rotation amount of the feeding motor 41. Further, the encoder 59 outputs a pulse signal having a number of pulses proportional to the rotation amount of the transport motor 42. Each of the encoders 58 and 59 is constituted by a rotary encoder connected in a state allowing rotational input to a drive shaft of a corresponding motor 41 or 42 or an end of a rotation shaft of a power transmission system that transmits the rotation of the drive shaft. The

  As shown in FIG. 6, the computer 52 includes a CPU 61, an ASIC 62 (Application Specific IC), a RAM 63, and a nonvolatile memory 64. The CPU 61 performs various controls such as a printing system, an operating system, and a display system by executing a control program (for example, a firmware program) stored in the nonvolatile memory 64. In particular, in the present embodiment, the CPU 61 executes the feeding control program shown in the flowchart of FIG. 14 stored in the nonvolatile memory 64, so that the AC power supply according to the difference in the power supply unit of the power supply source to the power supply device 51 is obtained. Motor control according to the mode or battery mode. Further, the RAM 63 temporarily stores print data, the calculation result of the CPU 61, and the like.

  Further, as shown in FIG. 6, the nonvolatile memory 64 should be changed when a command value for controlling the speed of the motors 35, 41, and 42 is obtained, and when the voltage drop is detected. A reference table TD2 that the CPU 61 refers to when determining the feeding operation mode and the feeding speed mode is stored. The control table TD1 is prepared for each of the motors 35, 41, and 42, and one control table TD1 corresponding to the motor is used.

  The computer 52 is connected to the display unit 14 via the display drive circuit 53. The computer 52 monitors the state of the printer 11 and the presence / absence of operation of the operation unit 15, and displays the menu and printing condition selection items according to the generated display event, various messages including warning messages, etc. through the display driving circuit 53. Display on the display unit 14.

  The computer 52 is connected to the recording head 23 via a head drive circuit 54. The computer 52 outputs print data received from a host device (not shown) or print data (dot data) generated based on image data read from a USB memory or a memory card to the head drive circuit 54 for recording. Ink droplets are ejected from nozzles corresponding to dots in the print data in the head 23. Examples of the host device include a mobile terminal such as a smartphone, a mobile phone, a tablet PC, and a personal digital assistant (PDA (Personal Digital Assistants)), or a personal computer.

  The computer 52 acquires the distance and speed from the position in the scanning direction X of the carriage 21 and the movement start position based on the pulse signal from the linear encoder 39, and controls the carriage based on the distance from the movement start position of the carriage 21. The command value is sequentially acquired with reference to the table TD1. Further, the computer 52 obtains the distance from the feeding start position of the paper P based on the pulse signal from the encoder 58, and sequentially obtains the command value with reference to the feeding control table TD1 based on this distance. To do. Further, the computer 52 acquires the distance from the feed start position or the feed start position of the paper P based on the pulse signal from the encoder 59, and refers to the control table TD1 for feeding or feeding based on this distance. To obtain the command value. The computer 52 outputs the command values to the motor drive circuits 55 to 57 to control the speed of the motors 35, 41, and 42.

  Note that the control table TD1 includes low-speed and high-speed acceleration / deceleration tables that are selectively used according to the mode at each time for each of the feeding motor 41 and the transport motor 42. The modes mentioned here include a plurality of printing modes that define printing speed and printing quality, a plurality of power modes prepared for each power source to be used, and a feed that specifies the skew removal operation performed during paper feeding. A feeding operation mode and a feeding speed mode that defines the driving speed of the motors 41 and 42 during paper feeding are included. Specifically, there are “draft mode” (high-speed low-quality mode) and “clean mode” (low-speed high-quality mode) as print modes. For each of these print modes, there is a high-speed acceleration / deceleration table for AC power supply mode. A low-speed acceleration / deceleration table for battery mode is available. Further, the computer 52 selects one of the plurality of acceleration / deceleration tables having different constant speeds (maximum speeds) according to the movement amount (feed amount or feed amount) of the paper P required at that time. For this reason, in the same mode, the longer the transport distance of the paper P, the faster the acceleration / deceleration table at a constant speed is selected as the acceleration / deceleration table referred to when the speed of the transport motor 42 is controlled. In addition, as the moving distance of the carriage 21 is longer, a faster acceleration / deceleration table having a constant speed is selected as the acceleration / deceleration table referred to when the speed of the carriage motor 35 is controlled.

  Further, the feeding operation mode is a mode that defines a skew removal operation performed during paper feeding. In the present embodiment, there are three types of feeding operation modes: a first feeding mode, a second feeding mode, and a third feeding mode, as an example. The first feeding mode is a mode that defines a feeding operation including a first skew removal operation. The first skew removal operation is, for example, a reverse butting operation. The second feeding mode is a mode that defines a feeding operation including a second skew removal operation. The second skew removing operation is a biting discharge operation as an example. Furthermore, the third feeding mode is a mode that defines a feeding operation that does not include a skew removal operation.

  Here, the first skew removal operation is a skew removal operation that requires driving of the plurality of motors 41 and 42. For this reason, the total power consumption of the motors 41 and 42 driven in the first feeding mode is relatively high. The second skew removing operation is a skew removing operation that requires only one of the motors 41 and 42 to be driven. For this reason, the total power consumption of the motors 41 and 42 driven in the second feeding mode is relatively low. Furthermore, since the third feeding mode does not include a skew removal operation, the total power consumption of the motors 41 and 42 driven in the third feeding mode is the lowest of the three feeding operation modes.

  In the present embodiment, there are three types of feeding speed modes: a high speed mode, a medium speed mode, and a low speed mode, as an example. In the high speed mode, the feeding motor 41 and the transport motor 42 are driven at a driving speed at which the paper P can be fed at the maximum speed U1. In the medium speed mode, the feeding motor 41 and the transport motor 42 are driven at a driving speed at which the paper P can be fed at the maximum speed U2. Further, in the low speed mode, the feeding motor 41 and the transport motor 42 are driven at a driving speed at which the paper P can be fed at the maximum speed U3. Here, the speeds U1 to U3 are indicated by functions whose values are determined by the feeding operation mode, and have the magnitude relationship of U1> U2> U3 if the feeding operation mode is the same.

  Thus, the sheet feeding operation is determined by the feeding operation mode and the feeding speed mode. In the reference table TD2 shown in FIG. 6, the feeding operation mode to be changed when the voltage drop is detected is set together with the priority when changing the setting. In addition, in the reference table TD2 shown in FIG. 6, the feeding speed mode to be changed when the voltage drop is detected is set together with the priority order when the setting is changed. In this embodiment, every time a voltage drop is detected, a feeding operation mode in which the power consumption of the motors 41 and 42 is smaller by one step than the previous feeding operation mode (first to third feeding modes) is selected. In this embodiment, every time a voltage drop is detected, a feeding operation mode that is one step lower than the previous feeding speed mode (any one of the high speed, medium speed, and low speed modes) is selected.

  As shown in FIG. 7, the power supply device 51 includes an input terminal 51 a that is electrically connected to the power plug 27 a of the AC adapter 27 connected to the power jack of the device body 12. In the power supply device 51, the AC adapter 27 transforms or rectifies an AC voltage (for example, a value in the range of 100V to 240V) from the commercial power supply 30 to a predetermined voltage Vac (a primary voltage (for example, a value in the range of 15 to 30V). )) Is input from the AC adapter 27 via the input terminal 51a.

  In addition, the power supply device 51 includes an input terminal 51 b that can be electrically connected to an output terminal (plus terminal) of the battery 28 housed in the device body 12. A predetermined voltage Vb (for example, a value in the range of 3 to 6 V) from the battery 28 is input to the power supply device 51 via the input terminal 51b.

  The power supply device 51 includes a first booster circuit 71 that is electrically connected to the output terminal of the battery 28 via the input terminal 51b. The first booster circuit 71 boosts the direct current of the predetermined voltage Vb from the battery 28 to a predetermined voltage V1 (for example, a value in the range of 8 to 15V) and outputs the boosted voltage. The power supply device 51 includes a second booster circuit 72 that boosts the input direct current of the predetermined voltage Vac or V1 to a predetermined voltage V2 (secondary voltage (for example, a value within a range of 30 to 60 V)). The predetermined voltage V2 is a drive voltage necessary for driving the motors 35, 41, and 42. The direct current of the predetermined voltage V2 boosted by the second booster circuit 72 is supplied to the head drive circuit 54 and the motor drive circuits 55 to 57. The predetermined voltage V2 is stepped down to a plurality of types of predetermined voltages by a step-down circuit (not shown) and then applied to the display drive circuit 53, the computer 52, the sensors 47 to 49, the encoders 39, 58, 59, etc. (see FIG. 6). , And supplied as each DC voltage necessary for each drive. The head drive circuit 54 may be configured to be supplied with a predetermined voltage obtained by stepping down the predetermined voltage V2.

  As shown in FIG. 7, the power supply device 51 includes a battery monitoring microcomputer (hereinafter referred to as “battery microcomputer 73”) that detects a predetermined voltage Vb input from the battery 28. The battery microcomputer 73 monitors the connection / disconnection of the battery 28 and manages the remaining amount of the battery 28 in the connected state. The battery microcomputer 73 is capable of bidirectional communication with the CPU 61, and transmits information relating to connection / disconnection of the battery 28, remaining amount information, and the like to the CPU 61 periodically or in response to a request from the CPU 61.

  The CPU 61 is configured to be able to detect the voltage of the input terminal 51 a that can be electrically connected to the AC adapter 27. The CPU 61 detects the connection of the AC adapter 27 and the connection of the battery 28 based on the voltage of the input terminal 51 a and the voltage of the input terminal 51 b acquired through the battery microcomputer 73. For this reason, the CPU 61 recognizes whether the power source of the current power supply source is the AC adapter 27 or the battery 28. Furthermore, the CPU 61 detects the disconnection of the connection with the commercial power supply 30 via the AC adapter 27 based on the voltage of the input terminal 51a. For example, the connection between the printer 11 and the commercial power supply 30 is cut off by pulling out the power plug 27a from the outlet and pulling out the power plug from the power jack. In the following description, extraction of the power plug 27a from the outlet and extraction of the power supply plug from the power jack may be collectively referred to as plug extraction.

  Further, the CPU 61 detects a voltage by a sensor 74 provided at a predetermined location on the power supply line between the second booster circuit 72 and the motor drive circuits 55 to 57. The CPU 61 monitors the voltage Vd detected by the sensor 74 to detect a voltage drop that occurs when the total power consumption of the printer 11 exceeds the power supply power. The location where the sensor 74 detects a voltage drop includes a junction 51c where the direct current from the AC adapter 27 and the direct current from the battery 28 merge, and a direct current input point to each motor drive circuit 55-57. Any position on the power supply line between the junction 51c and the input point may be used. The reason why the sensor 74 detects the voltage Vd at a position within the above range is that the sensor 74 detects the voltage at one location regardless of whether the power mode is the AC power mode or the battery mode. This is because a common voltage drop can be detected.

  FIG. 8 shows functional blocks constructed in the computer 52 that executes the feeding control program shown in FIG. As shown in FIG. 8, the computer 52 includes a main control unit 80, a motor control unit 81, a setting unit 82, a display control unit 83, and a head control unit 84. In this embodiment, the main control unit 80, the motor control unit 81, the setting unit 82, and the like constitute an example of the control unit.

  A main control unit 80 shown in FIG. 8 is responsible for overall control of the printing system, operation system, display system, and the like of the printer 11. The main control unit 80 detects the voltages of the input terminals 51a and 51b (see FIG. 7) in the power supply device 51, and based on the detected voltage, whether the power supply source is the AC power supply unit or the battery 28. Is determined. If the voltage of the input terminal 51a is a value when connected to the commercial power supply 30 via the AC adapter 27, the main control unit 80 recognizes that the power supply is an AC power supply unit. If the voltage at the input terminal 51a is not connected to the commercial power supply 30 via the AC adapter 27 and the voltage at the input terminal 51b is the value when connected to the battery 28, the main control is performed. The unit 80 recognizes that the power source is the battery 28.

  The main control unit 80 shown in FIG. 8 includes a mode management unit 91 that manages the print mode and the power mode. The mode management unit 91 manages the power mode as an AC power mode when the power source is an AC power unit, and manages the power mode as a battery mode when the power source is the battery 28. In the present embodiment, a battery 28 that is small in size and relatively small in capacity due to a request for downsizing the printer 11 and that has a smaller supply power than the supply power of the AC power supply unit is used. For this reason, the drive speeds of the motors 35, 41, 42 are changed according to the power supply mode. Specifically, the AC power supply mode is a high-speed drive mode that drives the motors 35, 41, and 42 at a relatively high speed, and the battery mode is a low-speed drive mode that drives the motors 35, 41, and 42 at a relatively low speed. For example, when the power source is switched from the AC power source unit to the battery 28 and the power source mode is switched from the AC power source mode to the battery mode, the motor being driven at that time is driven at a high speed. When there are a plurality of printers, the total power consumption of the printer 11 tends to be relatively larger than the power supplied by the power source. For example, as an example in which the power supply mode is switched from the AC power supply mode to the battery mode while the printer 11 is being driven, a user pulls out a plug.

  Further, the mode management unit 91 manages the print mode specified by the main control unit 80 based on the print condition information in the print data or the print condition information input and set by the operation of the operation unit 15, and the print mode is, for example, high speed low It manages whether it is a quality mode (for example, “draft mode”) or a low-speed high-quality mode (for example, “clean mode”). The main control unit 80 instructs the motor control unit 81 to control the speed of the motors 35, 41, and 42 according to the power mode and printing mode at that time managed by the mode management unit 91. Furthermore, the mode management unit 91 manages the feeding operation mode and the feeding speed mode. The feeding operation mode and the feeding speed mode are determined from the power supply mode and the printing mode. In the case of the AC power supply mode, the feeding operation mode is determined to be, for example, the first feeding mode with the reverse rotation abutting operation, and the feeding speed mode is determined to be the high speed mode. For example, in the battery mode, the feeding operation mode is determined as the second feeding mode with the biting and discharging operation, and the feeding speed mode is determined as the medium speed mode.

  8 acquires a voltage Vd (hereinafter also referred to as “detected voltage Vd”) detected by a sensor 74 (see FIG. 7) in the power supply device 51, and the detected voltage Vd is a threshold value. A detection unit 92 that detects a voltage drop below Vsh is provided. When the detection unit 92 detects a voltage drop, the main control unit 80 instructs the motor control unit 81 to stop the driving motor. Furthermore, if the main control unit 80 instructs the motor control unit 81 to stop the motor, and the paper is being fed, then the main control unit 80 again controls the motors 41 and 42 to avoid the occurrence of the same voltage drop (feeding). The operation mode and the feeding speed mode) are changed to the side where the total power consumption of the motors 41 and 42 is decreased by one step, and the set value of the control condition after the change is set in the setting unit 82.

  The main control unit 80 instructs the display control unit 83 to display a menu screen, various messages, and the like on the display unit 14 when a display event occurs, such as when the operation unit 15 is operated. Further, the main control unit 80 outputs print image data necessary for ejection control for ejecting ink from the nozzles of the recording head 23 to the head control unit 84, for example, one pass (raster) corresponding to one scan of the carriage 21. Send line by line). The head controller 84 develops the print image data and outputs the print image data to the head drive circuit 54, thereby causing the recording head 23 to eject ink droplets from the nozzles corresponding to the dots in the print image data, thereby printing on the paper P. Done.

  A motor control unit 81 shown in FIG. 8 includes a CR counter 94 that manages the position and moving distance of the carriage 21, an ASF counter 95 that manages the feeding position (feeding distance) of the paper P by the feeding motor 41, and a transport motor. A PF counter 96 that manages the transport position (transport distance) of the paper P by 42 is provided.

  The CR counter 94 is reset when the carriage 21 is at the origin position, adds the number of pulse edges when the carriage 21 moves forward based on the pulse signal from the linear encoder 39, and subtracts the number of pulse edges when the carriage 21 returns. Thus, the count value indicating the position of the carriage 21 in the scanning direction X is counted. The CR counter 94 also counts the count value corresponding to the moving distance of the carriage 21 by counting the number of pulse edges after the carriage motor 35 starts to be driven from the reset state.

  Further, the ASF counter 95 counts the count value corresponding to the feeding distance of the paper P by counting the number of pulse edges of the encoder 58 from the reset state when the feeding motor 41 starts driving. The PF counter 96 counts the count value corresponding to the transport distance of the paper P by counting the number of pulse edges of the encoder 59 from the reset state when the transport motor 42 starts driving. The PF counter 96 is reset when the paper detection sensor 48 detects the leading edge of the paper P during feeding, and corresponds to the transport position of the paper P by counting the number of pulse edges of the encoder 59 thereafter. The count value to be counted is also counted. Based on this count value, the motor control unit 81 recognizes the transport position of the paper P during printing.

  The motor control unit 81 obtains a target speed by referring to the control table TD1 based on the distances indicated by the count values of the counters 94 to 96, performs a feedback control calculation to bring the detected speed close to the target speed, and performs a command value ( For example, PWM command value) is acquired. Then, the motor control unit 81 outputs each command value to the motor drive circuits 55 to 57, and performs speed control of the motors 35, 41, and 42 with a speed profile corresponding to the printing mode and power supply mode at that time. Instead of feedback control, feedforward control may be performed.

  FIG. 9 shows the rotational speed U (rpm) (speed profile) when the motor is driven once and the current value I at that time. In the graph shown in FIG. 9, the horizontal axis represents the distance D from which the movement target (carriage 21 or paper P) has moved from the start of driving the motor, and the vertical axis represents the motor rotation speed U (rpm). The speed profile includes an acceleration region (acceleration profile) until the motor rotational speed U reaches 0 to zero, a constant speed region where the motor rotational speed U is held at the constant speed Uc, and a motor rotational speed U. Is composed of a deceleration region (deceleration profile) that decelerates from a constant speed Uc to a speed of 0 (zero) at which the moving object stops at the target position of the distance De.

  A plurality of speed profiles having different constant speeds Uc are set for each power mode. For example, in the speed profile for the AC power mode, the constant speed Uc is set to be higher than the speed profile for the battery mode. This is because the supply power of the battery 28 is smaller than the supply power of the AC power supply unit. In particular, in the present embodiment, the printer 11 is a mobile printer, and the power supplied to the battery 28 is relatively small because of the small battery 28 having a relatively small capacity in order to reduce its size. . In the battery mode, if the motor is driven at the same constant speed Uc as in the AC power supply mode, the power consumption of the printer 11 may exceed the supply power of the battery 28 and the system may be down. In order to avoid this, the constant speed Uc in the battery mode is kept lower than the constant speed Uc in the AC power supply mode, thereby reducing the power consumption of the motor in the battery mode. Such a speed profile in each power supply mode is set for each of the motors 35, 41, and 42. For example, a plurality of types of feed speed profiles having different constant speeds are set for the feed motor 41, and a plurality of types of transport speed profiles having different constant speeds are set for the transport motor 42.

  FIG. 10 shows a control table TD1 that is referred to by the computer 52 when the speeds of the motors 35, 41, 42 are controlled. The control table TD1 includes an acceleration table AT shown in FIG. 10A for determining an acceleration profile and a deceleration table DT shown in FIG. 10B for determining a deceleration profile. The acceleration table AT is a table showing a correspondence relationship between the distance D from the acceleration start position (position of distance 0) (distance D = 0, 1,..., Da) and the cycle CT. The deceleration table DT is a table showing a correspondence relationship between the distance D from the deceleration start position (position of the distance Dd) (distance D = 0, 1,..., Ds (= De−Dd)) and the cycle CT. .

  Here, as the distance D, the count values of the CR counter 94, the ASF counter 95, and the PF counter 96 are used. The cycle CT indicates the motor rotation cycle. In this example, the pulse edge cycle of the encoders 39, 58, and 59 is substituted, and the number of pulse edges of the clock signal input between the pulse edges of the encoders 39, 58, and 59 is used. Is obtained as a cycle CT. In this example, the motor speed control is performed by setting the cycle CT, which is the reciprocal of the motor rotation speed U, as the control target. However, the motor speed control may be performed using the motor rotation speed U as the control target. A plurality of such control tables TD1 are prepared for each of the motors 35, 41, and 42 in accordance with each mode, and in particular for the transport motor 42, a plurality of control tables having different constant speeds according to the transport distance. Are also available.

  The computer 52 reads, from the nonvolatile memory 64, the control table TD1 in which the constant speed Uc (target speed) corresponding to the mode at that time is set for each motor. Then, the computer 52 refers to the control table TD1 based on the distance D indicated by the count value of the counter and acquires the target cycle CTt. Then, the computer 52 feeds back the detection cycle (actual cycle) obtained by measuring the time between the pulse edges input from the encoders 39, 58, 59 to the target cycle CTt corresponding to the distance D at that time. A calculation is performed to obtain a command value for each of the motors 35, 41, and 42. Each command value is output from the computer 52 to the motor drive circuits 55 to 57, so that the motors 35, 41 and 42 are controlled in speed according to the speed profile shown in FIG. Each of the motor drive circuits 55 to 57 includes, for example, a switching circuit. By turning on / off switching elements in the switching circuit based on a PWM signal corresponding to the command value, each motor 35, 41, 42 has The motor current according to the command value flows.

  As shown in FIG. 9, in the acceleration region, the motor current is suddenly raised to accelerate the motor rotation speed U at the set acceleration, and the current peak Ip appears just before reaching the constant speed Uc (acceleration region). Thereafter, the current value I is decreased to the holding current Ic to reach the constant speed Uc, and is substantially held at the holding current Ic in the constant speed region. Then, the current value I starting to decrease from the deceleration start position Dd gradually decreases, and when the value becomes zero, the motor stops. As can be seen from the graph of FIG. 9, the power consumption of the motor is maximized at the current peak Ip that appears in the acceleration region. In the deceleration profile, braking is performed by switching the current direction to the reverse direction once in the deceleration process, and then the current direction is returned to the original value and then reduced to zero, thereby improving the motor stop position accuracy. May be.

  FIG. 11 shows the speed profile and current value I of the feeding operation in the first feeding mode with the reverse rotation abutting operation, and FIG. 12 shows the feeding operation in the second feeding mode with the biting discharge operation. A speed profile and a current value I are shown. In these figures, the upper graph shows the rotational speeds Ua and Ub of the feeding motor 41 and the transport motor 42 driven in the feeding process, and the lower graph shows the feeding motor 41 and the transport. Respective current values Ia and Ib with the motor 42 are shown. 11 and 12 show an example in the battery mode. In the AC power mode, the speed is basically set higher than in the battery mode, and the feeding motor 41 and the transport motor 42 are simultaneously set. Driving starts. In the graph of the speed profile shown in the upper part of each figure, the drive speeds of the motors 41 and 42 are different due to the difference in the gear ratio of the power transmission system, and the pair of the feed roller 20 and the transport roller. Each of the motors 41 and 42 of the feeding / conveying system is driven at a driving speed capable of rotating the sheet P at a rotational speed capable of conveying the paper P at the same speed.

  First, with reference to FIG. 11, the feeding operation in the first feeding mode with the reverse rotation abutting operation will be described. First, the driving of the feeding motor 41 is started, and the abutting operation is started in the feeding operation. The transport motor 42 starts reverse rotation driving with a slight delay from the start of driving of the feeding motor 41. In this way, by shifting the drive start timing of the feeding motor 41 and the transport motor 42, the generation timing of the current peak Ip of each of the motors 41 and 42 is shifted. As a result, the total power consumption of the motors 41 and 42 is not excessive and a voltage drop is unlikely to occur. The sheet P is fed downstream in the transport direction Y by the rotation of the feeding roller 20 in the section of time T1 to T2. Further, the conveyance roller pair 43 is reversely rotated by the reverse rotation driving of the conveyance motor 42. At time T2, the leading edge of the paper P reaches the transport roller pair 43 and is abutted against the reverse transport roller pair 43 (FIGS. 4A and 4B).

  For example, in the section from time T2 to time T3 in FIG. 11, the reverse contact state is maintained for a predetermined time, and the first skew removal operation (reverse rotation contact operation) for removing the skew of the paper P is performed. In the skew removal section from time T2 to time T3, the solid line in the figure indicates the current value when the feeding motor 41 is not loaded. In this skew removing section, a current I11 indicated by a two-dot chain line in the figure is the one when the paper P is plain paper, and the value of this current I11 falls within an allowable range. On the other hand, when the user mistakenly sets a plain paper and sets a photographic paper or a thick paper, an excessive current I12 indicated by a two-dot chain line in FIG. In this case, a voltage drop of the battery 28 occurs and the possibility of detecting the voltage drop increases.

  Then, when the reverse contact state is maintained for a predetermined time, the driving of both motors 41 and 42 is stopped at time T3. Specifically, the count value of the PF counter 96 that starts counting from the position where the leading edge of the paper P is detected by the paper detection sensor 48 is assumed to correspond to the condition at which the leading edge of the paper P hits the transport roller pair 43. When the transport roller pair 43 is rotated by a predetermined reverse abutting amount that can remove the maximum skew amount, the driving of the motors 41 and 42 is stopped.

  Next, both the feed motor 41 and the transport motor 42 are driven to rotate forward, and a cueing operation for transporting the paper P to the print start position in the transport direction Y is performed by the rotation of the feed roller 20 and the transport roller pair 43. (FIGS. 4C and 4D). In the middle of this cueing operation, the carriage motor 35 starts to be driven, the carriage 21 starts the first pass scanning operation from the home position to the paper P, and at the same time the cueing operation stops, the carriage 21 starts printing. The position is reached and printing (ink ejection) by the recording head 23 is started.

  Next, the feeding operation in the second feeding mode with the biting discharge operation will be described with reference to FIG. First, driving of the feeding motor 41 and the conveyance motor 42 is started in order to start the initial biting operation in the feeding operation. At this time, the motors 41 and 42 are driven to rotate forward so that the paper P is fed to a position where the leading end of the paper P protrudes from the transport roller pair 43 to the downstream side in the transport direction Y by a predetermined biting amount. An initial biting operation is performed. During the initial biting operation, the PF counter 96 starts counting from the position where the leading edge of the paper P is detected by the paper detection sensor 48. When the count value reaches a value corresponding to the desired biting amount, both motors The driving of 41 and 42 is stopped. In the section from time T11 to time T12 in FIG. 12, the leading end of the paper P that has reached the pair of transport rollers 43 is nipped by the pair of transport rollers 43 and is transported until a predetermined biting amount protrudes downstream in the transport direction Y. The biting operation is performed (see FIGS. 5A and 5B).

  As shown in FIG. 12, when the driving of both the motors 41 and 42 is stopped at the time T12 and the initial biting operation is finished, the feeding motor 41 is then stopped and the transport motor is operated in the section from the time T12 to T13. 42 is reversely driven by a predetermined amount of rotation. As a result, the transport roller pair 43 is reversed by the discharge amount, whereby a discharge operation for discharging the leading end portion of the paper P to the upstream side in the transport direction Y of the transport roller pair 43 is performed. By this discharge operation (skew removal operation), the sheet P is bent in a curved portion at the portion between the transport roller pair 43 and the feeding roller 20, and at the moment when the leading edge is discharged, the sheet P is restored with the restoring force of the bending. When returning, the skew of the paper P is removed (see FIGS. 5C and 5D).

  In this discharge operation section, a relatively large load is applied to the transport motor 42 due to the reaction force received from the paper P in the process of curving the paper P, and compared with the transport motor 42 to bring the actual speed closer to the target speed against the load. Large current flows. In the discharge section in the lower graph of FIG. 12, the solid line indicates the current value when there is no load, and the current I21 indicated by the two-dot chain line indicates the type of paper P ( For example, the current value when the discharge operation is performed on plain paper is shown. At this time, the power consumption of the printer 11 falls within the range of power supplied to the battery 28. On the other hand, when the user mistakenly sets the plain paper and sets the photographic paper or the thick paper, an excessive current I22 indicated by a two-dot chain line flows in the process of bending the paper P. In this case, the possibility that a voltage drop of the battery 28 is detected increases.

  At time T13, when the reverse drive of the transport motor 42 is stopped and the discharge operation is finished, the feed motor 41 and the transport motor 42 are next driven to rotate forward, and the feed roller 20 and the transport roller pair 43 are driven. By the rotation, a cueing operation for transporting the paper P to the print start position in the transport direction Y is performed. In the middle of this cueing operation, driving of the carriage motor 35 is started, the carriage 21 starts scanning the first pass of the paper P from the home position HP, for example, and the recording head 23 is moved in the scanning direction X at the same time as the cueing operation is stopped. When the printing start position is reached and the ejection of ink droplets from the nozzle is started, printing for one scan is started.

  FIG. 13 shows a graph when the detection unit 92 detects a voltage drop based on the detection voltage Vd acquired from the sensor 74. In this graph, the horizontal axis represents time T, and the vertical axis represents the detection voltage Vd. For example, the power plug 27a is pulled out from the outlet during printing driving of the printer 11 in the AC power mode, and the power supply unit is switched from the AC power supply unit to the battery 28, so that the power consumption of the printer 11 exceeds the power supply of the battery 28. Then, the voltage drop shown in the graph of FIG. 7 occurs. That is, when the detection voltage Vd drops from the voltage Vs (for example, the predetermined voltage V2) from the time Td and falls below the threshold Vsh at the time Tsh, the detection unit 92 determines that a voltage drop has occurred. Thus, when the detection unit 92 detects a voltage drop, if there are a plurality of motors being driven at that time, in the present embodiment, at least one of the plurality of motors being driven is stopped. When at least one motor is stopped, the power consumption of the printer 11 is reduced to be lower than the power supplied to the battery 28. For this reason, as shown in the graph of FIG. 7, the voltage dropped to the voltage Vr at the time Tr rises and returns to the original normal voltage Vs. For example, if the voltage continues to drop without recovering when a voltage drop occurs (the two-dot chain line in the graph in the figure), the voltage falls below the drive voltage Vc of the CPU 61, and all control of the computer 52 becomes impossible. The system goes down. In the present embodiment, the threshold value Vsh is set to a value larger than the drive voltage Vc of the CPU 61 (Vsh> Vc). When the detection voltage Vd falls below the threshold value Vsh, the motor being driven is stopped, and the system down of the printer 11 is avoided.

  Here, since the voltage drops relatively instantaneously (for example, 3 to 20 ms) when the voltage drops, there is no room for stopping the motor with deceleration when stopping the motor, and it is necessary to immediately cut off the motor current. In this case, if the motor that stops immediately is the carriage motor 35, the structure (parts) of the carriage drive system is damaged or the noise is relatively large due to the large stop impact when the carriage 21 is stopped due to the relatively large inertia. Becomes a problem. On the other hand, since the inertia of the feeding roller 20 and the roller pair 43 and 44 to be driven is relatively small, the stopping impact at the time of stopping is relatively small. For this reason, in the present embodiment, when two or more motors among the plurality of motors 35, 41, 42 are being driven when a voltage drop is detected, the feeding / conveying system motors 41, 42 are being driven. Is used, and the drive of the carriage motor 35 is not stopped.

  Next, the operation of the printer 11 will be described. Hereinafter, the feed control performed by the computer 52 executing the feed control program will be described with reference to FIG. When the computer 52 receives a print execution command by receiving print data or operating the operation unit 15, the computer 52 acquires the print mode from the specified print condition and determines whether the mode is the AC power mode or the battery mode by the mode management unit 91. . The main control unit 80 sets printing conditions corresponding to the combination of the printing mode and the power mode in the setting unit 82 and instructs the motor control unit 81 to perform printing control according to the setting contents. The printing conditions include a feeding operation mode that defines the type of skew removal operation during the feeding operation, and a feeding speed mode that defines the motor drive speed during the feeding operation. Then, information on the current feeding operation mode and feeding speed mode is set in the setting unit 82 by, for example, a 2-bit flag value. The computer 52 executes the feeding control program shown in FIG. 14 and drives and controls the recording head 23 and the motors 35, 41 and 42.

  When printing is started, first, the feed motor 41 and the transport motor 42 are driven in the feed process, and the paper P on the feed tray 16 is transported in the transport direction Y by the rotation of the feed roller 20 and the transport roller pair 43. To the printing start position. A skew removal operation is performed in the middle of paper feeding. In the skew removing operation, the feeding rollers 20 and the conveying roller pair 43 are rotated differently from normal rotation in order to apply an external force for removing skew to the paper P. Therefore, a relatively large load is applied to the motors 41 and 42. Therefore, the total power consumption of the motors 41 and 42 is relatively high. For example, in the AC power supply mode, since the power supplied by the power supply is relatively large, an appropriate type of skew removal operation corresponding to the information on the paper type or the like is selected. On the other hand, in the battery mode, since the power supplied by the power supply is relatively small, the first skew removing operation that requires driving of the plurality of motors 41 and 42 in order to prevent feeding failure due to the voltage drop of the power supply ( The reverse abutting operation) is not selected, and the second skew removing operation (the biting discharge operation) that is enough to drive one motor 42 is selected. The computer 52 controls the feeding of the printer 11 by executing the feeding control program shown in FIG. 14 every predetermined cycle time.

  First, in step S11, it is determined whether or not a voltage drop is detected. The main control unit 80 determines the voltage based on the detection voltage Vd from the sensor 74 that detects the voltage of the power supply line at a position between the junction 51c of the outputs of the AC adapter 27 and the battery 28 and the motor drive circuits 55 to 57. It is determined whether or not a descent is detected. This determination is performed by the detection unit 92. The detection unit 92 determines that a voltage drop has been detected when the detection voltage Vd falls below the threshold value Vsh. If a voltage drop is detected, the process proceeds to step S12. If a voltage drop is not detected, the routine ends.

  For example, even though the user sets “plain paper” as the paper type which is one of the printing conditions, the user mistakenly sets the thick paper in the feeding tray 16, or conversely, the thick paper is fed into the feeding tray 16. In spite of being set to “No”, there is a case where “plain paper” is input and set by mistake in the paper type. In these cases, a skew removal operation to be applied to “plain paper” having a relatively small load on the feeding mechanism is selected. However, in practice, a skew removing operation applied to a paper type having a relatively small load is performed on a thick paper having a large load on the feeding mechanism.

  For example, in the case where the reverse rotation abutting operation shown in FIG. 11 is applied, when the leading edge of the fed paper P hits the reverse conveying roller pair 43 at time T2, the paper P that is skewed at that time is the conveying roller. The skew is removed by turning around the corner portion of the tip that has come into contact with the pair 43 (FIGS. 4A and 4B). During the skew removal period in which the paper P rotates, the load applied to the feeding mechanism becomes relatively large. When the skew removal is completed and the paper P cannot even rotate, the load on the motors 41 and 42 increases rapidly. To do. For this reason, as shown in FIG. 11, the current I11 increases as shown by the two-dot chain line in FIG. 11 during the skew removal period from time T2 to time T3. Nevertheless, the plain paper current I11 is within the allowable range. However, in the case of thick paper, since an excessive current I12 indicated by a two-dot chain line in FIG. 11 flows in the motor 41 during this period, the power consumption of the motor 41 becomes excessive. As a result, the power consumption of the printer 11 exceeds the supply power of the power source, a power supply voltage drop occurs, and the detection unit 92 detects the voltage drop.

  On the other hand, for example, when the biting discharge operation shown in FIG. 12 is applied, the leading edge of the fed paper P reaches the transport roller pair 43 and is nipped by the transport roller pair 43 at time T11. Further, when the protruding length of the leading end of the paper P sent by the transport roller pair 43 from the transport roller pair 43 reaches a predetermined length, the driving of the motors 41 and 42 is stopped at time T12 at that time (FIG. 5 ( a), see (b)). After that, as illustrated in FIG. 12, the transport roller pair 43 is driven in the reverse direction in a section from time T <b> 12 to time T <b> 13, and the paper P is bent at a portion between the transport roller pair 43 and the feeding roller 20. During this bending process, the load received by the transport roller pair 43 from the paper P increases, and a relatively large current I22 flows through the transport motor 42. Still, in the case of plain paper, the current I21 of the transport motor 42 is within the allowable range. However, in the case of thick paper, since an excessive current I22 flows through the transport motor 42, the power consumption of the motor 41 becomes excessive, the power consumption of the printer 11 exceeds the power supply power, and the voltage drop of the power supply decreases. The voltage drop is detected by the detection unit 92.

  Returning to FIG. 14, in step S12, the motor being driven is stopped. The main control unit 80 instructs the motor control unit 81 to stop the motor. The motor control unit 81 that has received the instruction stops the motors 41 and 42 that are being driven, which are grasped from the sequence that is currently being executed. For example, if paper is being fed, the paper P stops in the middle of the feeding path. At this time, since the power consumption of the printer 11 is reduced by the drive stop of the motors 41 and 42, as shown in FIG. 13, the detection voltage Vd once dropped below the threshold value Vsh is the drive stop of the motors 41 and 42. At the same time (time Tr), it reverses upward and returns to a normal value as shown in FIG. As a result, system down of the printer 11 is avoided.

  In the next step S13, it is determined whether or not paper feeding is in progress. The main control unit 80 determines that paper feeding is in progress before receiving a notification of the end of the paper feeding sequence from the motor control unit 81. If the paper is being fed, the process proceeds to step S14. If not, the routine is terminated.

  In step S14, it is determined whether or not the paper detection sensor is ON. That is, it is determined whether or not the leading edge of the paper P has passed the detection target position of the paper detection sensor 48. If the paper detection sensor is in the ON state, the process proceeds to step S15. If the paper detection sensor is not in the ON state, that is, if it is in the OFF state, the process proceeds to step S16.

  In step S15, blank paper is discharged. That is, the sheet P is discharged (discharged) as a blank sheet. This process is performed when the motor control unit 81 drives the transport motor 42 and rotates the transport roller pair 43 and the discharge roller pair 44 to transport the paper P downstream in the transport direction Y. If there is no paper P on the feed tray 16, the user sets the paper P discharged from the blank or another paper P on the feed tray 16.

  In step S16, the previous feeding operation mode is confirmed. The main control unit 80 reads information (for example, flag value) related to the previous feeding operation mode set in the setting unit 82, and confirms the previous feeding operation mode from the read flag value. In this example, the feeding operation mode includes the first feeding mode (with reverse rotation abutting operation), the second feeding mode (with biting discharge operation), and the third feeding mode (without skew removal operation). Since there are three types, one of these modes is confirmed as the previous feeding operation mode.

In step S17, it is determined whether or not the previous time is the first feeding mode. If it is the first feeding mode, the process proceeds to step S18, and if it is not the first feeding mode, the process proceeds to step S19.
In step S18, the second feeding mode is set. That is, the setting unit 82 sets the second feeding mode with the second skew removing operation (the biting discharge operation) as the next feeding operation mode.

In step S19, it is determined whether or not the previous time is the second feeding mode. If it is the second feeding mode, the process proceeds to step S20, and if it is not the second feeding mode, the process proceeds to step S21.
In step S20, the third feeding mode is set. That is, the setting unit 82 sets the third feeding mode without the skew removal operation as the next feeding operation mode. When the previous time is the third feeding mode, the setting of the third feeding mode is maintained as it is.

  Thus, the total power consumption of the motors 41 and 42 is smaller in the next feeding operation mode than in the previous feeding operation mode, unless the previous feeding operation mode is already the third feeding mode with the smallest load. For example, it is changed to another feeding operation mode with a small one-stage load.

  In step S21, the previous feeding speed mode is confirmed. The main control unit 80 reads information (for example, a flag value) related to the previous feeding speed mode set in the setting unit 82, and confirms the previous feeding speed mode from the read flag value. In this example, since there are three types of feeding speed modes, a high speed mode, a medium speed mode, and a low speed mode, one of these modes is confirmed as the previous feeding speed mode.

In step S22, it is determined whether or not the previous time was the high speed mode. If it is the high speed mode, the process proceeds to step S23, and if it is not the high speed mode, the process proceeds to step S24.
In step S23, the medium speed mode is set. That is, when the previous time is the high speed mode, the setting unit 82 sets, for example, a medium speed mode having a smaller one-stage load than the previous time in the speed mode as the next feeding speed mode.

In step S24, it is determined whether or not the previous time is the medium speed mode. If it is the medium speed mode, the process proceeds to step S25, and if it is not the medium speed mode, the process proceeds to step S26.
In step S25, the low speed mode is set. That is, when the previous time is the medium speed mode, the setting unit 82 sets, for example, a low speed mode having a smaller one-stage load than the previous time in the speed mode as the next feeding speed mode. When the previous time is the low speed mode, the low speed mode setting is maintained as it is.

  In this way, unless the previous feed speed mode is already the low speed mode with the least load on the motors 41 and 42, the next feed speed mode is the total of the motors 41 and 42 than the previous feed speed mode. It is changed to a feeding speed mode that consumes less power.

  Thus, after the next feeding operation mode and feeding speed mode are changed to a setting that requires less total power consumption of the motors 41 and 42, paper feeding is resumed in step S26. That is, the feeding operation of the paper P is retried. If the paper P is already set on the feeding tray 16 and the paper presence sensor 47 is in the detection state, the main control unit 80 instructs the motor control unit 81 to perform a feeding operation. If the paper P is not set in the feeding tray 16 and the paper presence sensor 47 is in a non-detection state, the user sets the paper P in the feeding tray 16 and the paper presence sensor 47 is in a detection state. Accordingly, the motor control unit 81 is instructed to perform a feeding operation. Receiving the instruction, the motor control unit 81 drives and controls the motors 41 and 42 according to the current feeding operation mode and the feeding speed mode set in the setting unit 82.

  As a result, the feeding operation of the paper P is retried in the feeding operation mode and the feeding speed mode in which the total power consumption of the motors 41 and 42 is smaller than the previous time. For example, when the skew removal operation during the previous feeding operation is a reverse abutting operation that requires driving of the plurality of motors 41 and 42, the single feeding of the motor 42 is sufficient for the feeding operation to be retried this time. The biting discharge operation is performed. For example, when the skew removal operation during the previous feeding operation is a biting discharge operation that drives one motor 42, the skew removal operation is not performed in the feeding operation that is retried this time. For example, when the previous feeding operation mode is the third feeding mode, in the feeding operation to be retried this time, the motors 41 and 42 are driven without the skew removal operation in the same third feeding mode. Also in this case, if the feeding speed mode is changed to the one-stage low speed side, the total power consumption of the motors 41 and 42 can be reduced compared to the previous time, and a voltage drop is detected during feeding at the time of retry. There is no.

  Further, for example, when the feeding speed mode that defines the driving speed of the motors 41 and 42 driven in the previous feeding operation is the high speed mode, in the feeding operation to be retried this time, the motors 41 and 42 are in the medium speed mode. Driven. For example, when the previous feeding speed mode is the medium speed mode, in the feeding operation to be retried this time, the motors 41 and 42 are driven in the low speed mode. For example, when the previous feeding speed mode is the low speed mode, in the feeding operation to be retried this time, the motors 41 and 42 are driven in the same low speed mode. Also in this case, if the feeding operation mode is changed to the one-stage low-load side, the total power consumption of the motors 41 and 42 is smaller than the previous time, and a voltage drop is detected by feeding at the time of retry. There is nothing.

  Thus, the possibility that a voltage drop is detected during the feeding operation at the time of retry is greatly reduced, and the paper P set on the feeding tray 16 is fed to the printing start position by the feeding operation to be retried this time.

  Further, if the paper P stopped in the previous feeding operation is detected by the paper detection sensor 48, the blank paper is discharged, and the feeding operation of the paper P is performed again from the position set on the feeding tray 16. Is done. On the other hand, if the paper P stopped in the middle of the previous feeding operation is not detected by the paper detection sensor 48, the feeding operation of the paper P is performed from a position on the feeding path without being discharged. Will be redone. For this reason, when the feeding operation is retried, the paper P is detected by the paper detection sensor 48 in the middle of feeding, and the feeding position of the paper P can be correctly grasped based on the detected position. Can feed accurately to the position. For example, if the retry of the feeding operation of the paper P is started from the position detected by the paper detection sensor 48, the feeding at the time of retry is based on the previous position detected by the paper detection sensor 48 during the previous feeding. You will know the position. However, if the position of the paper P is shifted due to an abnormal stop at the time of detecting a voltage drop, the reliability of the accuracy of the feeding position is low, so the paper P that has been fed at the retry of the feeding operation and stopped at the printing start position The reliability of the stop position accuracy is reduced. On the other hand, in this embodiment, the paper P is detected by the paper detection sensor 48 in the middle of the feeding operation at the time of retry, and control is performed to stop the paper P at the print start position based on the detected position. Therefore, the paper P can be stopped at the print start position with high positional accuracy.

  Also, when a voltage drop is detected during the retry feeding operation and the feeding operation fails again, a feeding operation mode is set in which the power consumption of the motors 41 and 42 is smaller than the previous feeding operation mode. In addition, a feeding speed mode is set in which the power consumption of the motors 41 and 42 is smaller than that of the previous feeding speed mode. For this reason, even if the retry feeding operation fails, a mode with a smaller load on the motors 41 and 42 is reset each time, so that the frequency of repeated feeding operation failures can be reduced. In this embodiment, if the feeding operation retry fails, and the feeding operation fails twice in succession, the main control unit 80 instructs the display control unit 83 to display the paper on the display unit 14, for example, An error message is displayed to inform the user that there is a possibility of some kind of mistake.

  Further, when the feeding operation fails and the settings of the feeding operation mode and the feeding speed mode are changed, the changed settings are maintained for the same print job. For example, if the feeding operation mode and the feeding speed mode are restored to the original settings during the feeding operation of the subsequent paper P in the same print job, an error occurs every time the remaining pages of the same print job are fed. Occurs, the setting is changed each time, and the extra retry feeding operation increases. However, in the present embodiment, since the changed settings of the feeding operation mode and the feeding speed mode are maintained in the same print job, an error hardly occurs during the feeding operation of the remaining pages of the same print job.

  In the present embodiment, the mode at the time of voltage drop detection is the first mode, and the first mode is the mode at the time of the next feeding retry that requires less total power consumption of the motors 41 and 42 of the feeding system. Two modes are set. As described above, the first mode and the second mode are relatively determined. For example, in the case of the feeding operation mode, the mode at the time of voltage drop detection is the first feeding mode accompanied by the reverse rotation abutting operation, and the mode at the time of feeding retry is the second feeding mode accompanied by the biting discharge operation. Suppose. In this case, the first feeding mode corresponds to the first mode, and the second feeding mode corresponds to the second mode. Further, the reverse rotation butting operation corresponds to the first skew removal operation, and the biting and discharging operation corresponds to the second skew removal operation. Further, it is assumed that the mode at the time of voltage drop detection is the second feeding mode accompanied by the biting discharge operation, and the mode at the time of feeding retry is the third feeding mode without the skew removing operation. In this case, the second feeding mode corresponds to the first mode, and the third feeding mode corresponds to the second mode.

  Further, for example, in the case of the feeding speed mode, it is assumed that the mode at the time of voltage drop detection is the high speed mode and the mode at the time of feeding retry is the medium speed mode. In this case, the high speed mode corresponds to the first mode, and the medium speed mode corresponds to the second mode. Further, it is assumed that the mode at the time of voltage drop detection is the medium speed mode and the mode at the time of feeding retry is the low speed mode. In this case, the medium speed mode corresponds to the first mode, and the low speed mode corresponds to the second mode. Further, when both the feeding operation mode and the feeding speed mode are employed as in the present embodiment, the first mode and the second mode include both elements of the feeding operation mode and the feeding speed mode, respectively. .

According to the embodiment described in detail above, the following effects can be obtained.
(1) When a drop in voltage supplied from the power supply unit to the motors 41 and 42 is detected during driving of the motors 41 and 42 that feed the paper P in the first mode, the driving of the motors 41 and 42 is stopped. As a result, although the paper feeding fails, the system down of the printer 11 can be avoided. Thereafter, the feeding of the paper P is retried by changing to the second mode, which has lower power than the first mode, and driving the motors 41 and 42. The feeding of the paper P in the second mode has a lower total power consumption of the motors 41 and 42 than in the first mode, so that a voltage drop hardly occurs at the time of retry, and the paper P is fed to the printing start position to start printing. can do. Therefore, even if the paper P is fed again, the frequency of repeated feeding failures can be reduced.

  (2) The first and second modes are modes that specify a skew removal operation for removing the skew of the paper P performed during the feeding of the paper P. When the voltage drop is detected, the first mode including the first skew removal operation during the feeding of the paper P is the second skew removal operation in which the total power consumption of the motors 41 and 42 is lower than that in the first skew removal operation. Is changed to the second mode including the sheet P, and the feeding of the paper P is retried. Therefore, it is possible to avoid the repeated failure of feeding the paper P due to the voltage drop and to feed the paper P.

  (3) The first and second modes are modes that define the driving speed of the motors 41 and 42 that are being fed. Since the driving speed of the motors 41 and 42 during feeding is lower in the second mode than in the first mode, a voltage drop is less likely to occur during feeding of the paper P in the second mode, The paper P can be fed while avoiding repeated failure of feeding the paper P due to a voltage drop.

  (4) When the mode is changed from the first mode to the second mode, the second mode is maintained until the job when the mode is changed to the second mode is completed. Therefore, it is possible to suppress the failure of feeding the subsequent paper P in the same job. Therefore, it is possible to suppress a decrease in printing throughput due to the retry of the feeding of the paper P every time during the same job.

  (5) In the first skew removal operation, the plurality of motors 41 and 42 are driven, and in the second skew removal operation, a smaller number of motors 42 are driven than in the first skew removal operation. Therefore, even if the voltage drop is detected in the first skew removing operation in which the plurality of motors 41 and 42 are driven and the feeding of the paper P fails, the number of motors 42 is smaller than that in the first skew removing operation. The feeding retry is performed in the second mode in which the driven second deskew operation is performed. For this reason, it is possible to reduce the frequency with which the failure of feeding the paper P due to the voltage drop is repeated, and to feed the paper P to the print start position with the smallest number of retries.

  (6) The printer 11 includes a paper detection sensor 48 (an example of a first sensor) that detects the paper P in the middle of the feeding path. If the paper detection sensor 48 does not detect the paper P when the driving of the motors 41 and 42 is stopped during the feeding of the paper P in the first mode, the paper P is not discharged and stopped during the feeding. If the paper detection sensor 48 detects the paper P, the feeding of the next paper P is retried after the paper P is discharged. For this reason, in any case, the paper P can be detected by the paper detection sensor 48 during feeding at the time of retry, and the paper P can be fed to the target position with high positional accuracy based on the detected position. As a result, high-quality printing can be performed after feeding.

  (7) A paper presence / absence sensor 47 (an example of a second sensor) that detects the presence / absence of the paper P set on the feeding tray 16 (an example of a placement unit) is provided. Retry of feeding the paper P set on the feeding tray 16 is started. That is, if the paper P is set in the feeding tray 16 and the paper presence sensor 47 is in the detection state, the retry of feeding the paper P in the second mode is started, while the paper is loaded in the feeding tray 16. If P is not set, when the user sets the paper P and it is detected by the paper presence sensor 47, the retry of feeding the paper P in the second mode is started. For this reason, when the feeding of the paper P in the first mode fails, the feeding of the paper P in the second mode is started, so that the user does not need to issue a printing instruction again.

  (8) The printer 11 is a power source capable of switching the power source between the AC adapter 27 and the battery 28 that converts the AC power supplied via the power plug 27a inserted into the outlet of the commercial power source 30 into a direct current and outputs it. A device 51 is provided. When the power plug 27a is pulled out from the outlet, the voltage drop is detected because the power source is switched from the AC adapter 27 to the battery 28, and the motors 41 and 42 are stopped. The paper feeding is retried by driving the motors 41 and 42 in the feeding operation mode and the feeding speed mode in which the total power consumption is low. Therefore, it is possible to prevent the system from being down when the power plug 27a is pulled out from the outlet, and to reduce the frequency of repeated feeding failures.

  (9) The computer 52 detects the voltage drop by monitoring the voltage by the sensor 74 at a position on the power line between the junction 51c of the outputs of the AC adapter 27 and the battery 28 and the motor drive circuits 55 to 57. To do. Therefore, even in a configuration in which power is switched between the AC adapter 27 and the battery 28 and power is supplied to the motors 41 and 42, only one voltage monitoring point is required to detect a voltage drop. In particular, since the voltage boosted at the position on the power supply line between the second booster circuit 72 and the motor drive circuits 55 to 57 for boosting the outputs of the AC adapter 27 and the battery 28 is monitored by the sensor 74, the voltage drop is reduced. Detection sensitivity is improved.

  (10) When the motors 41 and 42 are driven by the power of the battery 28 and the paper P is fed in the feeding operation mode and the feeding speed mode at that time, a voltage drop is detected and the motors 41 and 42 are detected. When the drive is stopped, the motors 41 and 42 are driven in the second mode to retry feeding the paper P. Therefore, a voltage drop occurs during feeding using a battery 28 with relatively small power supply as a power source, and a voltage drop is relatively likely to occur. The sheet P in the feeding operation mode and the feeding speed mode at that time Even if the feeding fails, the paper P can be fed in a mode in which the power consumption of the motors 41 and 42 is lower.

  (11) When the printer 11 feeds the paper P by the automatic feeding device 17, even if the voltage drop occurs in the mode (first mode) at that time and the feeding of the paper P fails, the motor 41, Since the feeding of the paper P is retried in the mode (second mode) in which the power consumption of 42 is smaller, the frequency of the failure of feeding the paper P again can be reduced.

In addition, the said embodiment can also be changed into the following forms.
-Only one of the feeding operation mode and the feeding speed mode may be changed when the feeding operation fails when the voltage drop is detected. For example, the feed speed mode may be abolished and only the feed operation mode may be changed, or the feed operation mode may be abolished and only the feed speed mode may be changed. Further, when adopting both the feeding operation mode and the feeding speed mode, the plurality of modes may be changed one by one instead of changing each mode simultaneously. For example, if the skew removal operation is changed when the first feeding fails, the feeding speed mode is changed when feeding fails even at the next first retry, and feeding fails at the second retry In the case where the feeding operation is not performed after the third retry, the speed mode is changed for the second time.

  The mode to be changed when the feeding operation at the time of detecting the voltage drop is failed may be the printing mode or the power mode. For example, when the feeding operation fails in the high speed low quality mode (“draft mode”), the mode may be changed to the low speed high quality mode (“clean mode”). In this case, if the printing operation is retried in the mode after changing only the feeding operation without changing the mode, a printing image having a desired quality can be acquired after the feeding operation is successful. Similarly, if the power supply mode is changed to the battery mode when feeding fails in the AC power mode, and only the feeding operation at the time of retrying is performed in the battery mode, the feeding at the time of retrying succeeds and the high speed is achieved. Printing can be realized.

  -Other methods may be used for the skew removal operation. For example, an abutting method (abutting operation) may be employed in which the leading edge of the paper P fed by the feeding roller 20 abuts against the stopped conveying roller pair 43 to remove the skew. For example, the feeding operation mode with the abutting operation may be the third feeding mode, and no skew removal operation may be the fourth feeding mode. The abutting operation corresponds to a second skew removing operation that requires only one motor 41 of the plurality of motors 41 and 42 to be driven.

  If the feeding in the mode (first mode) with the first skew removal operation (for example, reverse contact operation) fails due to the detection of the voltage drop, the feeding operation mode (the first mode) at the next retry (2 mode) may be changed to a mode without skew removal operation. For example, when the feeding fails both in the reverse rotation butting operation and the biting and discharging operation, the feeding setting at the next retry may be set to no skew removal operation.

-If the feeding operation fails when a voltage drop is detected, the paper may always be discharged. Further, the feeding operation may be resumed from the stop position when the feeding operation fails without always discharging the blank paper.
The first motor may be replaced with a configuration including two feeding motors 41 and a conveying motor 42, and may be a single motor (for example, a conveying motor) common to the feeding system and the conveying system.

  A scanning device that can use only one of the AC power source and the battery 28 as a power source may be used. For example, a printing apparatus that can use only an AC power source as a power source or a printing apparatus that can use only a battery as a power source may be used. In the case of a scanning device that can be driven by an AC power source, an AC conversion unit that converts alternating current from a commercial power source into direct current may be incorporated in the apparatus main body 12 instead of the AC adapter 27.

  The loading unit is not limited to the feeding tray 16 and may be a feeding cassette that can be loaded in a state where a plurality of sheets P are accommodated. Further, instead of the feeding tray 16 of the automatic feeding device 17, a manual feed tray may be used. In this case, it is preferable to provide a paper presence sensor 47 that detects the presence or absence of the paper P set in the feeding cassette or the manual feed tray.

  -Each functional unit constituting the control unit is realized by software by a CPU that executes a program, by hardware by an electronic circuit such as an ASIC, or by cooperation of software and hardware. Also good.

The feeding mechanism is not limited to the roller-type feeding mechanism, and may be a belt-type feeding mechanism that transports a medium on a belt.
The medium is not limited to paper, and may be a resin film, a metal foil, a metal film, a resin-metal composite film (laminate film), a woven fabric, a nonwoven fabric, a ceramic sheet, or the like.

  A printer (printing apparatus) as an example of an electronic device is not limited to an ink jet printer as long as it can print on a medium such as paper, and may be a dot impact printer or a laser printer. Further, the printing apparatus is not limited to a printer having only a printing function, and may be a multifunction machine having a scanner function, a copy function, or the like. Furthermore, the printing apparatus is not limited to a serial printer, but may be a line printer or a page printer. The printing apparatus is not limited to a mobile printer, and may be a small, medium, or large printer. For example, a business printer or a large format printer may be used. Furthermore, the printing apparatus may be a textile printer.

  -An electronic device is not limited to a printer (printing apparatus). For example, a scanner device may be used. For example, a feeding mechanism (for example, a document feeding device (auto document feeder)) that feeds a document as an example of a medium is provided, and the mode is changed when a feeding failure is detected due to a power supply voltage drop detection in the document feeding process. It may be configured to retry feeding. Even with this type of scanner device, it is possible to reduce the frequency with which the failure of feeding a medium (original) is repeated. In addition, the present invention can be applied to a feeding device of an electronic device provided with a feeding device that feeds a medium.

  DESCRIPTION OF SYMBOLS 11 ... Printer as an example of an electronic device, 12 ... Apparatus main body, 14 ... Display part, 15 ... Operation part, 16 ... Feeding tray as an example of a mounting part, 17 ... Automatic feeding as an example of a feeder Device: 20 ... Feed roller constituting transport mechanism, 21 ... Carriage, 23 ... Recording head as an example of printing unit, 27 ... AC adapter as an example of power supply unit, 27a ... Power supply plug, 28 ... Example of power supply unit , 30... Commercial power supply, 35... Carriage motor as an example of a second motor, 39... Linear encoder, 41... 42... Conveying motor that constitutes an example of a feeding device and a conveying unit and that constitutes an example of a motor, 43... Conveying that constitutes an example of a feeding device and a conveying unit A pair of rollers, 44... A pair of discharge rollers constituting a conveyance unit, 47... A paper presence sensor as an example of a second sensor, 48... A paper detection sensor as an example of a first sensor, 51. 52: Computer as an example of a control unit, 55-57: Motor drive circuit as an example of a drive circuit, 80 ... Main control unit, 81 ... Motor control unit, 82 ... Setting unit, 91 ... Mode management unit, 92 ... Detection , 93... Determination unit, P... Paper as an example of a medium.

Claims (10)

A feeding mechanism for feeding the medium;
A motor as a power source for driving the feeding mechanism;
A control unit for driving and controlling the motor,
Wherein, during operation of said motor for feeding a medium in a first mode comprising a first skew correction operation during feeding, detecting a voltage drop of the supply voltage of the power supply unit due to an overcurrent of the motor Then, the driving of the motor is stopped, the second skew removing operation that requires less power than the first mode is changed to the second mode including the medium feeding, and the motor is driven by driving the motor. A feeding device characterized by retrying feeding. A plurality of the motors;
The controller drives the plurality of motors in the first skew removal operation, and drives a smaller number of motors in the second skew removal operation than in the first skew removal operation. The feeding device according to claim 1 . The first and second modes are speed modes that define a driving speed of the motor during the feeding,
Wherein the control unit changes the first mode to the second mode is a slower rate mode, supply according to claim 1 or 2, characterized in feeding apparatus. 2. The control unit according to claim 1, wherein when the first mode is changed to the second mode, the control unit maintains the second mode until the job when the second mode is changed ends. The feeding device according to any one of claims 1 to 3 . A first sensor for detecting the medium in the middle of the feeding path;
If the first sensor has not detected the medium when the driving of the motor is stopped while the medium is being fed in the first mode, the controller feeds the medium without discharging the medium. the retry, the first sensor is feeding retry the following medium after discharging the medium if the detecting the medium, it claimed in any one of claims 1 to 4, characterized in Feeding device. A placement unit on which the medium is set;
A second sensor for detecting the presence or absence of the medium set in the mounting portion,
When the first sensor detects the medium and ejects the medium, the control unit starts retrying the feeding of the medium set in the mounting unit when the medium is detected by the second sensor. The feeding device according to claim 5 . The power supply device further comprises a power supply device capable of switching a power supply between an AC power supply unit that converts an alternating current fed through a plug inserted into a commercial power outlet into a direct current and outputs the direct current, and a battery. Item 7. The feeding device according to any one of Items 1 to 6 . The control unit detects a voltage drop by monitoring a voltage at a position on a power supply line between a confluence of outputs of the AC power supply unit and the battery and a drive circuit of the motor. Item 8. The feeding device according to Item 7 . The drive of the motor is stopped when a voltage drop is detected during feeding of the medium, and the first mode when the voltage drop is detected is changed to the second mode that requires lower power. control by the control unit for feeding retry the medium feeding apparatus according to any one of claims 1 to 8, wherein the motor is performed when it is driven by battery power, it is characterized by . An electronic apparatus comprising the said feeding apparatus according to any one of claims 1 to 9.