JP7251427B2 - MEDIUM CONVEYING DEVICE AND IMAGE FORMING APPARATUS - Google Patents

Description

The present invention relates to a medium conveying device and an image forming device.

2. Description of the Related Art Conventionally, image forming apparatuses such as printers, copiers, facsimiles, and multi-function machines, such as electrophotographic printers, are provided with an image forming unit, in which the image forming unit is uniformly charged by a charging roller. The surface of the photoreceptor drum exposed to light is exposed by an LED head to form an electrostatic latent image, and the electrostatic latent image is developed with toner supplied from a toner cartridge to form a toner image. . Then, the toner image is transferred onto paper as a medium by a transfer roller and fixed on the paper by a fixing device, thereby forming an image and printing.

As a medium, label paper in which a plurality of labels are temporarily attached to a long backing paper is used. Roll paper, which is roll-shaped label paper, is accommodated in the unit, the delivery motor is driven, the delivery roller pair is rotated, and the label paper is delivered from the roll paper accommodation unit, and the transport motor is driven to rotate the transport roller pair. As it is rotated, the fixing motor is driven to rotate the heating roller and the pressure roller, and the label paper is conveyed on the paper conveying path.

An optical sensor is arranged in the paper transport path, and the position of the front end of the label in the transport direction of the label paper is detected by the optical sensor as a reference position. That is, the cutting position, the position where the image is written on each label, that is, the image writing position, etc. are set.

By the way, in the label paper printing apparatus, when a stepping motor is used for the feed motor and the transport motor, and a DC motor is used for the fixing motor, the feed of the label paper to the paper transport path and the transport of the label paper on the paper transport path are started. Sometimes, when the fixing motor overshoots, the label paper is suddenly pulled downstream, and along with this, the transport roller pair and delivery roller pair are strongly rotated in the direction to send the label paper downstream, A backlash is formed between the gears that transmit rotation to the transport roller pair and delivery roller pair.

When the backlash is formed, the actual transport amount when transporting the label paper from the reference position to the cutting position differs from the target transport amount, and the label paper cannot be cut accurately at the cutting position. .

Therefore, a motor control method is provided in which, when a plurality of different types of motors are driven to convey the label paper, slack is formed in the label paper by adjusting the rotation speed of each motor (for example, , see Patent Document 1).

JP 2014-46466 A

However, even if the conventional motor control method is applied to the conventional label paper printing apparatus, if the fixing motor becomes old and the rotation speed cannot be adjusted accurately, or if the type of label paper is different, There may be variations in the slack that is formed. In this case, not only is it impossible to cut the label paper with high accuracy at the cutting position, but also the slack formed in the label paper increases, causing creases or the like to be formed on the label paper. can no longer be transported to

SUMMARY OF THE INVENTION The present invention provides a medium conveying apparatus and an image forming apparatus that solve the problems of the conventional label paper printing apparatus described above and can accurately cut the medium at the cutting position and smoothly convey the medium. intended to

For this reason, in the medium conveying apparatus of the present invention, the first and second driving sources are arranged in the medium conveying path, and the first driving source is driven to rotate to convey the medium. and a second medium conveying member arranged downstream of the first medium conveying member in a medium conveying path, rotated by driving the second drive source, and conveying a medium. a member, a rotation transmission system for transmitting the rotation of the first drive source to the first medium transporting member, and a cutter arranged upstream of the second medium transporting member in the medium transport path for cutting the medium. When a predetermined time has passed after the overshoot caused by the driving of the unit and the second driving source is eliminated and the driving state transitions from the acceleration state to the constant speed state, the second driving state in the medium transport path is reached. 1. a slack forming unit that forms slack between a second medium conveying member; and a cut that cuts the medium by driving the cutter unit after the slack is formed between the first and second medium conveying members. and a processing unit.

According to the present invention, in the medium conveying device, the first and second driving sources are arranged in the medium conveying path, and the first driving source is rotated by driving the first driving source to convey the medium. and a second medium conveying member arranged downstream of the first medium conveying member in a medium conveying path, rotated by driving the second drive source, and conveying a medium. a member, a rotation transmission system for transmitting the rotation of the first drive source to the first medium transporting member, and a cutter arranged upstream of the second medium transporting member in the medium transport path for cutting the medium. When a predetermined time has passed after the overshoot caused by the driving of the unit and the second driving source is eliminated and the driving state transitions from the acceleration state to the constant speed state, the second driving state in the medium transport path is reached. 1. a slack forming unit that forms slack between a second medium conveying member; and a cut that cuts the medium by driving the cutter unit after the slack is formed between the first and second medium conveying members. and a processing unit.

In this case, when the overshoot generated in the second drive source is eliminated and the drive state transitions from the acceleration state to the constant speed state after a predetermined time has passed, the first and second drive sources in the medium transport path A slack is formed between the medium conveying members, and after the slack is formed, the cutter unit is driven to cut the medium, so the medium can be cut at the cutting position with high accuracy.

2 is a control block diagram of the label paper printer according to the first embodiment of the present invention; FIG. 1 is a perspective view of a label paper printer according to a first embodiment of the present invention; FIG. 1 is a perspective view showing a main part of a label paper printer according to a first embodiment of the invention; FIG. 1 is a schematic diagram of a label paper printer according to a first embodiment of the present invention; FIG. 1 is a conceptual diagram of a label paper printer according to a first embodiment of the present invention; FIG. 1 is a perspective view of a cutter unit according to a first embodiment of the invention; FIG. It is a figure which shows the principal part of the cutter unit in the 1st Embodiment of this invention. FIG. 4 is a conceptual diagram for explaining the operation of the slackness sensor according to the first embodiment of the present invention; FIG. 4 is a conceptual diagram for explaining the state of the label paper when feeding and conveying are started in the first embodiment of the present invention; FIG. 4 is a diagram for explaining the cutting position of the label paper according to the first embodiment of the present invention; FIG. 4 is a time chart for explaining the operation of the cutter unit according to the first embodiment of the present invention; FIG. 4 is a flow chart showing the operation of the control unit according to the first embodiment of the present invention; It is a figure for demonstrating operation|movement of the slack formation part in the 1st Embodiment of this invention. 4 is a time chart showing changes in rotation speed of a feeding motor, a conveying motor, and a fixing motor according to the first embodiment of the present invention; 9 is a flow chart showing the operation of a control unit according to the second embodiment of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, a label paper printing apparatus as an image forming apparatus and as a printer will be described.

FIG. 2 is a perspective view of the label paper printer according to the first embodiment of the present invention, FIG. 3 is a perspective view showing the essential parts of the label paper printer according to the first embodiment of the present invention, and FIG. FIG. 5 is a schematic diagram of the label paper printer according to the first embodiment of the invention, FIG. 5 is a conceptual diagram of the label paper printer according to the first embodiment of the invention, and FIG. 6 is the first embodiment of the invention. 7 is a view showing the essential parts of the cutter unit according to the first embodiment of the present invention, and FIG. 8 is for explaining the operation of the slackness sensor according to the first embodiment of the present invention. It is a conceptual diagram of. 2 to 4, the negative direction of the X-axis is the front of the label paper printer 10, the positive direction of the X-axis is the rear of the label paper printer 10, and the positive direction of the Y-axis is the upward direction of the label paper printer 10. , the negative direction of the Y-axis indicates the downward direction in the label paper printer 10, the positive direction of the Z-axis indicates the leftward direction in the label paper printer 10, and the negative direction of the Z-axis indicates the rightward direction in the label paper printer 10. FIG.

In the figure, reference numeral 10 denotes a label paper printer. The label paper printer 10 includes a device main body 11, which is the main body of the label paper printer 10. In addition, a cover unit 12 is arranged above the apparatus main body 11 so as to be openable and closable, and a toner cartridge unit Ct as a developer accommodating device is arranged on the side of the cover unit 12 on the apparatus main body 11. Prepare.

In the label paper printing apparatus 10, as a medium, a plurality of labels Lbi (i=1, 2, . A die-cut label paper) P is used, and an image is formed on each label Lbi of the label paper P.

Further, Cs1 is a housing of the apparatus main body 11, Cs2 is a housing of the lid unit 12, the housing Cs1 has a front panel Wf1, a side panel Ws1 and a rear panel Wr1, and the housing Cs2 has a front wall. Wf2, side wall Ws2, back wall Wr2 and top wall Wt2. The top wall Wt2 includes a main body cover Wta and a roll cover Wtb arranged to be swingable about an axis Cn2 with respect to the main body cover Wta. , a paper exit 13 is formed.

The lid unit 12 is disposed immediately below the roll cover Wtb, and is a roll paper storage section 17 as a medium storage section for storing roll-shaped label paper P, that is, roll paper 16, and as a paper supply section. , a paper transport unit 18 as a first medium transport unit disposed immediately below the main body cover Wta for transporting the label paper P drawn out from the roll paper storage unit 17, and downward from the paper transport unit 18 A plurality of arms (three in this embodiment, not shown) are provided projecting toward each other, and an LED head 22 as an exposure device is provided at the lower end of each arm.

Below the sheet conveying section 18 in the apparatus main body 11, a developer image forming section Q1 for forming toner images as developer images of a plurality of colors, yellow, magenta and cyan in this embodiment, is arranged. A transfer unit u1 is disposed below the developer image forming portion Q1 in the apparatus main body 11 to sequentially transfer the toner images onto the label paper P to form a color toner image. A sheet conveying section 23 serving as a second medium conveying section for conveying the label paper P sent from the sheet conveying section 18 is disposed behind the agent image forming section Q1 (on the side of the rear panel Wr1). In front of the transfer unit u1 (on the side of the front panel Wf1), a paper conveying section 24 serving as a third medium conveying section for sending the label paper P sent from the paper conveying section 23 to the paper exit 13 is arranged.

A delivery roller pair 19 serving as a first transport member and delivery member is rotatably disposed at a location adjacent to the front wall Wf2 of the roll paper storage section 17 . By rotating the delivery roller pair 19, the label paper P is delivered from the roll paper container 17 to the paper transport path Rt1 as the medium transport path.

The label paper P is transported along the paper transport path Rt1 in order between the paper transport units 18 and 23, the developer image forming unit Q1 and the transfer unit u1, and the paper transport unit 24 in this order.

A paper end sensor Srx as a first medium detection unit for detecting the end (rear end) of the label paper P is disposed adjacent to the roll paper storage unit 17 in the paper transport path Rt1. A conveying roller pair 20 as a second conveying member is rotatably disposed downstream of the paper end sensor Srx in the conveying path Rt1, and a conveying roller pair as a third conveying member is disposed downstream of the conveying roller pair 20. 21 is rotatably arranged, and an optical sensor Sp as a second medium detection section and as a position detection section is arranged downstream from the conveying roller pair 21, and downstream from the optical sensor Sp. A cutter unit 26 as a cutting section is disposed at the end of the cutter unit 26, and a conveying roller pair 27 as a fourth conveying member is rotatably disposed downstream from the cutter unit 26. A slackness sensor 28 is provided as a detection unit.

The optical sensor Sp detects the presence or absence of the label paper P on the paper transport path Rt1, a predetermined portion of the label paper P, the position of the leading edge eg1 of the label Lbi in this embodiment, and the like. For this purpose, a transmissive sensor is used as the optical sensor Sp.

In the present embodiment, the position of the leading edge eg1 of the label Lbi is detected as a reference position, and the controller 61 (FIG. 1), which will be described later, sets the length of the label paper P based on the reference position. For each label Lbi, the cutting position, that is, the position where the image is written, that is, the image writing position, etc. are set. In this embodiment, the position of the leading edge eg1 of the label Lbi is detected as the reference position, but the position of the trailing edge of the label Lbi can also be detected as the reference position.

The cutter unit 26 is a rotary cutter, and as shown in FIGS. 6 and 7, includes a cutter box 51, a cutter boss 52 rotatably supported in the cutter box 51 by a shaft sh1 in the direction of arrow b, A cutter arm 53 is supported by a shaft sh2 in the cutter box 51 so as to be capable of swinging in the direction of an arrow c. A rotary blade 55 having a shape is provided, and a swing blade 56 is provided at the tip of the cutter arm 53 .

As the cutter boss 52 rotates, the rotary blade 55 is rotated, and as the cutter arm 53 swings, the oscillating tooth 56 is pressed against the rotary blade 55, and the contact portion between the rotary blade 55 and the oscillating tooth 56 is The label paper P that is moved in the width direction of the label paper P (the axial direction of the cutter boss 52) and conveyed in the direction of arrow d is cut.

The slack sensor 28 detects slack formed in the label paper P by the slack forming unit Pr2, which will be described later. For this purpose, as shown in FIG. 8, the slackness sensor 28 has a sensor lever 58 that is brought into contact with the label paper P and is swung according to the amount of slackness, and a sensor It has a sensor unit sa that generates an output, turns on when slackness is detected, and turns off when slackness is not detected.

The label paper P is conveyed along with the rotation of the conveying roller pair 20 and 21. The optical sensor Sp detects the presence or absence of the label paper P, the position of the leading edge, etc. After being cut by the cutter unit 26, the conveying roller pair 27 rotates. Then, the slackness sensor 28 detects slackness.

On the downstream side of the slack sensor 28, a writing sensor Sr1 is arranged as a third medium detecting section for detecting the position where image formation on the label paper P is started, that is, the writing position. The writing sensor Sr1 detects the presence or absence of the label paper P. FIG.

A transfer section for transferring the toner image onto the label paper P is formed between the developer image forming section Q1 and the transfer unit u1 on the downstream side of the writing sensor Sr1 in the paper transport path Rt1. A fixing device 45 as a fixing device is arranged downstream from the section, and an ejection sensor Sr2 as a fourth medium detection section for detecting the front end of the label paper P is arranged downstream from the fixing device 45, A discharge roller pair 46 as a medium discharge member for sending the label paper P to the paper exit 13 is rotatably arranged downstream from the discharge sensor Sr2. An image forming section for forming an image on the label paper P is configured by the developer image forming section Q1, the transfer unit u1, and the fixing device 45. As shown in FIG.

In the figure, reference numerals 31Y, 31M, and 13C denote image forming units for yellow, magenta, and cyan, respectively. a body drum 32, a charging roller 33 as a charging device rotatably disposed in contact with the photosensitive drum 32, and a developer carrier rotatably disposed in contact with the photosensitive drum 32. a developing roller 35, a toner supplying roller 36 as a developer supplying member rotatably disposed in pressure contact with the developing roller 35, and toners as developers of respective colors disposed above the toner supplying roller 36; A toner storage chamber 39 or the like is provided as a developer storage chamber for storing the toner. The toner storage chamber 39 is formed inside the toner cartridge unit Ct.

In each of the image forming units 31Y, 31M, and 31C, the charging roller 33 is rotated as the photosensitive drum 32 is rotated, and the surface of the photosensitive drum 32 is uniformly charged. The surface of the body drum 32 is exposed by the LED head 22 and an electrostatic latent image is formed on the photosensitive drum 32 as a latent image.

As the photosensitive drum 32 is rotated, the developing roller 35 and the toner supply roller 36 are rotated, and the toner supplied from the toner storage chamber 39 is supplied to the developing roller 35 by the toner supply roller 36, thereby developing. A toner layer consisting of a thin layer of toner is formed on the roller 35 .

Subsequently, the toner on the developing roller 35 adheres to the electrostatic latent image, forming a toner image of each color on the photosensitive drum 32 .

The transfer unit u1 includes a driving roller R1 as a first roller, a driven roller R2 as a second roller, and a traveling member that is stretched by the driving roller R1 and the driven roller R2 so as to be free to travel in the direction of arrow a. A transfer belt 41, and a transfer device arranged to face each photoreceptor drum 32 via the transfer belt 41, transfers each color toner image onto the label paper P to form a color toner image on the label paper P. A transfer roller 43 is provided as a member.

The fixing device 45 includes a heating roller 48 as a first fixing member and a pressure roller 49 as a second fixing member. A color image is formed by heating and pressing the color toner image on P.

The feed roller pair 19 and the transport roller pairs 20 and 27 constitute a first medium transport member, and the heating roller 48 and pressure roller 49 constitute a second medium transport member.

After the writing position of the label paper P is detected by the writing sensor Sr1, the label paper P is sent to the transfer section. The toner images are sequentially transferred onto the label paper P to form a color toner image on the label paper P. As shown in FIG.

Subsequently, the label paper P is sent to the fixing device 45, where the color toner image is heated and pressed to fix it onto the label paper P, forming a color image on the label paper P. be done. After that, the label paper P is discharged from the paper exit 13 to the outside of the apparatus main body 11 by the discharge roller pair 46 .

The label paper printer 10 includes a delivery motor M1 as a delivery drive unit for rotating the delivery roller pair 19, and a transport motor M1 for rotating the transport roller pairs 20, 21, and 27, which will be described later. A transport motor M2, which will be described later, as a drive unit, a discharge motor (not shown) as a discharge drive unit for rotating the discharge roller pair 46, and a cutting drive for rotating the rotary blade 55 in the cutter unit 26 a cutter motor (not shown) as a unit, and a drum (not shown) as an image forming drive unit for rotating the photosensitive drum 32, the charging roller 33, the developing roller 35 and the toner supply roller 36 in the developer image forming unit Q1. a motor, a transfer motor (not shown) as a transfer drive unit for rotating the driving roller R1 and the transfer roller 43 in the transfer unit u1, and a fixing device for rotating the heating roller 48 and the pressure roller 49 in the fixing device 45 A fixing motor M3 and the like, which will be described later, are provided as a driving unit for the fixing.

In this embodiment, the feeding motor M1 and the conveying motor M2 constitute a first driving source, and the fixing motor M3 constitutes a second driving source.

Further, in the present embodiment, the label paper P is used as the medium, the position of the front edge eg1 of the label Lbi is detected by the optical sensor Sp, and a transmissive sensor is used as the optical sensor Sp. However, if a long sheet of paper with marks such as black marks attached at a certain pitch in the longitudinal direction is used as the medium, the presence or absence of the sheet, the position of the mark on the sheet, etc. For detection, a reflective sensor is used as optical sensor Sp.

Next, the control device of the label paper printer 10 will be described.

FIG. 1 is a control block diagram of the label paper printer according to the first embodiment of the present invention.

In the figure, reference numeral 10 denotes a label paper printer; 61, a controller for controlling the entire label paper printer 10; 2, a RAM as a storage device; 64, an operation panel; 65, an interface unit for receiving print data and control commands from a host computer (not shown) as a host device; Sp, an optical sensor;

Further, M1 is a feeding motor, Dr1 is a motor driver for driving the feeding motor M1 and rotating the feeding roller pair 19, M2 is a conveying motor, Dr2 drives the conveying motor M2, and the pair of conveying rollers 20 and 21 , 27, M3 is a fixing motor, and Dr3 drives the fixing motor M3 to rotate the pressure roller 49 (FIG. 4) of the fixing device 45 and the heating roller 48. , and 26 is a cutter unit.

The heating roller 48 and the pressure roller 49 not only have large diameters, but also the pressure roller 49 is pressed against the heating roller 48 with a large force. The load applied is large. Therefore, in this embodiment, a DC motor is used as the fixing motor M3.

On the other hand, since the delivery roller pair 19 and the transport roller pairs 20, 21, and 27 have small diameters, the load applied to the delivery motor M1 and the transport motor M2 when rotating the delivery roller pair 19 and the transport roller pairs 20, 21, and 27 is reduced. small. Therefore, in this embodiment, stepping motors are used as the delivery motor M1 and the transport motor M2.

The control unit 61 includes a CPU as an arithmetic unit (not shown), an input/output port, a timer as a timing member, and the like, and performs various processes based on programs recorded in the ROM 62 . Various set values are recorded in the ROM 62 in addition to the programs described above. In the RAM 63, image data for forming an image on the label paper P, which is generated based on the print data, and various control data are temporarily recorded. The RAM 63 is used as a working memory when the CPU performs calculations.

Further, the control section 61 includes a conveying processing section Pr1, a slack forming section Pr2, a cutting condition fulfillment waiting section Pr3, a cutting position setting section Pr4, a cutting processing section Pr5, and the like.

The transport processing unit Pr1 drives the feed motor M1, the transport motor M2 and the fixing motor M3 to feed the label paper P (FIG. 5) from the roll paper container 17 and transport it along the paper transport path Rt1.

The slack forming unit Pr2 accelerates the delivery motor M1 and the transport motor M2 to increase their rotational speeds so that the transport speed of the label paper P on the upstream side of the slack sensor 28 is reduced to the transport speed of the label paper P on the downstream side of the slack sensor 28. By increasing the speed higher than the speed, slack is formed in the label paper P between the heating roller 48 and the pressure roller 49 and the conveying roller pair 27, in this embodiment, between the conveying roller pair 27 and the transfer section. .

For this reason, the slack forming unit Pr2 reads the sensor output of the slack sensor 28, and when the slack is not formed and the sensor output is off, the feeding motor M1 and the conveying motor M2 are accelerated to increase the rotation speed, thereby increasing the slack. is formed and the sensor output is ON, the feeding motor M1 and the conveying motor M2 are decelerated to reduce the rotation speed.

In the present embodiment, slack is formed in the label paper P by accelerating the feeding motor M1 and the conveying motor M2 and increasing their rotational speeds. Slack can also be created by lowering

After the fixing motor M3 starts to be driven, the cut condition establishment standby unit Pr3 waits for the fixing motor M3 to transition to a constant speed state and the first cutting condition to be satisfied, and outputs a lock signal for the fixing motor M3. is turned on to wait for the second cutting condition to be satisfied, slack is formed in the label paper P, the slack sensor 28 is turned on to wait for the third cutting condition to be satisfied.

The cut position setting unit Pr4 sets the middle position of each label Lbi as the cut position when the reference position is detected by the optical sensor Sp.

The cut processing unit Pr5 sets the cut timing based on the distance between the cut position and the front edge eg1 of the label Lbi and the rotational speed of the conveying motor M2, and when the current time reaches the cut timing based on the time measurement by the timer. , drive the cutter unit 26 to cut the label paper P.

The operation panel 64 comprises a display unit (not shown) comprising an LED screen for displaying the status of the label paper printer 10, and switches, keys, etc. for the operator to input instructions to the label paper printer 10. An operation unit (not shown) is provided. Note that when the operation panel 64 is formed by a touch panel, the operation panel 64 functions as a display section and also as an operation section.

Control unit 61, optical sensor Sp, slackness sensor 28, motor drivers Dr1 to Dr3, feeding motor M1, conveying motor M2, fixing motor M3, feeding roller pair 19, conveying roller pairs 20, 21, 27, fixing device 45, cutter A medium conveying device is configured by the unit 26 and the like.

In the label paper printer 10, the fixing motor M3 overshoots when the label paper P is fed to the paper transport path Rt1 and transported along the paper transport path Rt1. In this case, if the label paper P is cut by the cutter unit 26 while the rotation speed of the fixing motor M3 is unstable, a cut failure occurs.

Next, the state of the label paper P when feeding and transport of the label paper P are started will be described.

FIG. 9 is a conceptual diagram for explaining the state of the label paper when feeding and transporting are started in the first embodiment of the present invention, and FIG. FIG. 11 is a diagram for explaining the cutting position, and FIG. 11 is a time chart for explaining the operation of the cutter unit according to the first embodiment of the present invention. In FIG. 11, the horizontal axis represents time.

In the figure, P is label paper conveyed in the direction of arrow d, Lbi (i=1, 2, . A cutter unit, 27 a conveying roller pair, 28 a slackness sensor, 45 a fixing device, 48 a heating roller, and 49 a pressure roller.

The delivery roller pair 19 includes a delivery roller 19a and a pinch roller 19b arranged in pressure contact with the delivery roller 19a. A gear gr3 is attached to one end of the delivery roller 19a. is engaged with the gear gr4 for transmitting the rotation of the feeding motor M1 (FIG. 1), and as the gear gr4 is rotated in the direction of the arrow f, the gear gr3 and the feeding roller 19a move in the direction of the arrow g. be rotated.

The conveying roller pair 27 includes a conveying roller 27a and a pinch roller 27b arranged in pressure contact with the conveying roller 27a. A gear gr5 is attached to one end of the conveying roller 27a. A gear gr6 for transmitting the rotation of the conveying motor M2 is meshed with the roller 27a, and as the gear gr6 is rotated in the direction of arrow h, the gear gr5 and the conveying roller 27a are rotated in the direction of arrow i. be done.

A rotation transmission system is configured by the gears gr3 to gr6.

Then, when the transport processing unit Pr1 of the control unit 61 drives the delivery motor M1 by the motor driver Dr1, drives the transport motor M2 by the motor driver Dr2, and drives the fixing motor M3 by the motor driver Dr3, the delivery roller pair 19 is rotated to start feeding the label paper P to the paper transport path Rt1, and the pair of transport rollers 27, the heating roller 48 and the pressure roller 49 are rotated to transport the label paper P along the paper transport path Rt1. is started.

At this time, the transport processing unit Pr1 drives the delivery motor M1, the transport motor M2, and the fixing motor M3, and controls the rotation speed to reach the target speed. When the rotation speed becomes higher than the target speed and an overshoot occurs, the pressure roller 49 is strongly rotated in the direction of arrow j.

As a result, the label paper P is abruptly pulled downstream, and along with this, the transport roller pair 27 and delivery roller pair 19 on the upstream side of the slackness sensor 28 strongly rotate in the direction to send the label paper P downstream. A backlash μ1 is formed between the gears gr5 and gr6 that transmit the rotation to the conveying roller pair 27, and a backlash μ2 is formed between the gears gr3 and gr4 that transmit the rotation to the delivery roller pair 19.

When the overshoot generated in the fixing motor M3 is eliminated, the driving state of the fixing motor M3 transitions from the acceleration state to the constant speed state. , the behavior of the fixing motor M3 may make the transport of the label paper P unstable. In this case, if the actual transport amount when transporting the label paper P from the reference position to the cutting position differs from the target transport amount, the label paper P cannot be cut accurately at the cutting position.

That is, as shown in FIG. 10, the cut position set between the adjacent labels Lb1 and Lb2 by the cut position setting unit Pr4 is LA, and the transport processing unit Pr1 moves the label paper P to the leading edge of the label Lb1. The label Lb1 is transported from the reference position eg1 to the cutting position LA. If the actual transport amount differs from the target transport amount representing the distance between the front edge eg1 of the label Lb1 and the cutting position LA, an erroneous cut occurs. The label paper P is cut at the position LB.

In the cutter unit 26, the contact portion between the rotary blade 55 (FIG. 7) and the swing blade 56 is moved in the width direction of the label paper P to cut the label paper P. If the conveying state of the label paper P becomes unstable during the lapse of the predetermined time τ1 during which the cutter motor is driven, as shown in FIG. , cutting defects occur.

Therefore, in the present embodiment, the overshoot generated in the fixing motor M3 is eliminated, the backlashes .mu.1 and .mu.2 are absorbed, and the label paper P is cut after the transport of the label paper P is stabilized. there is

Next, the operation of the control section 61 of the label paper printer 10 will be described.

FIG. 12 is a flow chart showing the operation of the control section in the first embodiment of the present invention, FIG. 13 is a diagram for explaining the operation of the slack forming section in the first embodiment of the present invention, and FIG. 4 is a time chart showing changes in rotation speed of a feeding motor, a conveying motor, and a fixing motor according to the first embodiment of the invention;

In FIG. 13, P is label paper, 61 is a control unit, 19 is a feed roller pair consisting of a feed roller 19a and pinch roller 19b, 27 is a feed roller pair consisting of a feed roller 27a and pinch roller 27b, 28 is a slackness sensor, 45 is a fixing device having a heating roller 48 and a pressure roller 49; M1 is a feeding motor; M2 is a conveying motor; M3 is a fixing motor; Dr1 is a motor driver for driving the feeding motor M1; A motor driver Dr3 is a motor driver for driving the fixing motor M3.

In FIG. 14, Nc is the rotation speed of the delivery motor M1 and the conveying motor M2, Nf is the rotation speed of the fixing motor M3, and N* is the target speed.

In the control unit 61, first, the transport processing unit Pr1 (FIG. 1) drives the delivery motor M1, the transport motor M2 and the fixing motor M3 by the motor drivers Dr1 to Dr3.

As a result, the rotational speeds Nc and Nf increase at a predetermined rate of change and reach the target speed N* at timing t1.

At this time, since the feeding motor M1 and the conveying motor M2 are stepping motors, the drive state transitions from the acceleration state to the constant speed state, and the rotation speed Nc is maintained at the target speed N*. Since it is composed of a motor, the rotation speed Nf becomes higher than the target speed N*, an overshoot occurs, and a backlash μ1 occurs between the gears gr5 and gr6 (FIG. 9) that transmit the rotation to the conveying roller pair 27. A backlash μ2 is formed between the gears gr3 and gr4 that transmit the rotation to.

Therefore, the cut condition establishment standby unit Pr3 waits until the overshoot generated in the fixing motor M3 is eliminated, the drive state is changed from the acceleration state to the constant speed state, and the first cut condition is established. In the present embodiment, the rotational speed Nf falls within a predetermined range of the target speed N*, which is within ±5 [%] in the present embodiment,
(1-0.05)・N*≦Nf≦(1+0.05)・N*
Then, the drive state of the fixing motor M3 transitions from the acceleration state to the constant speed state.

Subsequently, when the first cut condition is satisfied at timing t2, the lock signal is turned on in the cut condition satisfaction standby unit Pr3, and the rotation speed Nf of the fixing motor M3 is sufficiently stabilized to satisfy the second cut condition. wait to do In the present embodiment, the predetermined time after the rotational speed Nf falls within ±5% of the target speed N*, in the present embodiment, the time τ2 which is three times the control cycle tc.
τ2=3×tc
, the lock signal is turned on. The time .tau.2 is set to a time necessary for absorbing the backlashes .mu.1 and .mu.2 between the gears gr3 and gr4 as the fixing motor M3 overshoots.

Then, when the second cutting condition is satisfied at timing t3, the slack forming unit Pr2 accelerates the feeding motor M1 and the conveying motor M2 to form slack in the label paper P, and the cut condition satisfaction standby unit Pr3 It waits until the slack is formed in P and the slack sensor 28 is turned on and the third cutting condition is satisfied. The slack forming unit Pr2 continues to accelerate the delivery motor M1 and the conveying motor M2 until the slack sensor 28 is turned on, increasing the rotation speed Nc. keep the value.

Subsequently, when the third cutting condition is satisfied, the cutting position setting section Pr4 sets the cutting position LA based on the reference position detected by the optical sensor Sp.

Then, the cutting processing unit Pr5 sets the cutting timing based on the distance between the cutting position LA and the leading edge eg1 of the label Lb1 and the rotation speed Nc of the conveying motor M2, and the current time is cut based on the time measured by the timer. When the timing comes, the cutter unit 26 is driven to cut the label paper P.

Subsequently, the slack forming unit Pr2 decelerates the feeding motor M1 and the conveying motor M2.

Since the cutter unit 26 cuts the label paper P over the time τ1 (FIG. 11), the rotation speed Nc of the label paper P increases to If it becomes unstable, a cutting defect occurs. Therefore, the slack forming part Pr2 continues to form slack in the label paper P until the cutting of the label paper P by the cutter unit 26 is completed.

As described above, in the present embodiment, when the first to third cut conditions are satisfied, that is, the driving state of the fixing motor M3 transitions from the acceleration state to the constant speed state, and then the lock signal is turned on. , and the label paper P is cut when the slack is formed in the label paper P.

Next, the flowchart will be described.
Step S1 The transport processing unit Pr1 drives the feeding motor M1, the transport motor M2 and the fixing motor M3.
Step S2: The cut condition fulfillment standby unit Pr3 waits for the drive state to transition from the acceleration state to the constant speed state. If the drive state has changed from the acceleration state to the constant speed state, the process proceeds to step S3.
Step S3: The cut condition fulfillment standby unit Pr3 waits for the lock signal to turn on. When the lock signal is turned on, the process proceeds to step S4.
Step S4 The slack forming part Pr2 accelerates the feeding motor M1 and the conveying motor M2.
Step S5: The cut condition fulfillment standby unit Pr3 waits for the label paper P to become slack. If slack is formed in the label paper P, the process proceeds to step S6.
Step S6 The cutting position setting unit Pr4 sets the cutting position LA.
Step S7 The cut processor Pr5 cuts the label paper P. As shown in FIG.
Step S8 The slack forming unit Pr2 decelerates the feeding motor M1 and the conveying motor M2, and ends the process.

As described above, in this embodiment, when the overshoot occurs in the fixing motor M3, the overshoot is eliminated, and when the time τ2 elapses after the drive state transitions from the acceleration state to the constant speed state, Slack is formed in the label paper P between the heating roller 48 and the pressure roller 49 and the transport roller pair 27 in the paper transport path Rt1, and after the slack is formed, the cutter unit 26 is driven to cut the label paper P. Therefore, the label paper P can be cut accurately at the cutting position LA.

In addition, while the cutter unit 26 is cutting the label paper P, slack is continuously formed in the label paper P, so it is possible to prevent the occurrence of cut defects.

In the present embodiment, when the time τ2 elapses after the overshoot is eliminated and the drive state of the fixing motor M3 transitions from the acceleration state to the constant speed state, and the lock signal is turned on, the feeding motor M1 is turned on. Then, the conveying motor M2 is accelerated to form slack in the label paper P between the heating roller 48/pressure roller 49 and the conveying roller pair 27. However, the time τ2 has passed and the lock signal is output. If the label paper P is already slack when the switch is turned on, the label paper P is excessively slack as the feeding motor M1 and the transport motor M2 are accelerated.

Therefore, a second embodiment of the present invention that prevents excessive slack in the label paper P will be described. The same reference numerals are assigned to components having the same structure as in the first embodiment, and the effects of the same embodiment are used for the effects of the invention due to having the same structure.

FIG. 15 is a flow chart showing the operation of the control section in the second embodiment of the invention.

In the control unit 61, first, the transport processing unit Pr1 (FIG. 1) operates a feed motor M1 as a drive unit for feeding, a transport motor M2 as a drive unit for transport, and a drive for fixing by motor drivers Dr1 to Dr3. A fixing motor M3 as a unit is driven.

Next, the cut condition establishment standby unit Pr3 waits until the overshoot that has occurred in the fixing motor M3 is eliminated and the drive state transitions from the acceleration state to the constant speed state to satisfy the first cut condition. When the cut condition 1 is established, the lock signal is turned on, and the rotational speed Nf of the fixing motor M3 is sufficiently stabilized to wait until the second cut condition is established. When the second cut condition is established, A slack is formed in the label paper P as the medium, the slack sensor 28 as the slack detecting section is turned on, and it is determined whether or not the third cutting condition is satisfied.

If slack is not formed in the label paper P, the slack sensor 28 is not turned on, and the third cutting condition is not satisfied, the slack forming unit Pr2 accelerates the feeding motor M1 and the transport motor M2 to Wait for slack to form in P.

On the other hand, when slack is formed in the label paper P, the slack sensor 28 is turned on, and the third cutting condition is satisfied, the slack forming unit Pr2 either sets the feeding motor M1 and the conveying motor M2 to a constant speed state, or After decelerating, the cutting position setting unit Pr4 sets the cutting position LA (FIG. 10) based on the reference position detected by the optical sensor Sp as the second medium detection unit.

Subsequently, the cut processing unit Pr5 determines again whether slack is formed in the label paper P and the slack sensor 28 is turned on. , the cutting timing is set based on the distance between the cutting position LA and the front edge eg1 of the label Lb1, and the rotational speed Nc of the conveying motor M2, and the current time is the cutting timing based on the timing by a timer (not shown) as a timing member. Then, the cutter unit 26 as a cutting section is driven to cut the label paper P.

On the other hand, when slack is not formed in the label paper P and the slack sensor 28 is not turned on, the slack forming unit Pr2 accelerates the feed motor M1 and the transport motor M2 until the label paper P is slack. .

Next, the flowchart will be described.
Step S11 The transport processing unit Pr1 drives the feeding motor M1, the transport motor M2 and the fixing motor M3.
Step S12 The cut condition fulfillment standby unit Pr3 waits for the drive state to transition from the acceleration state to the constant speed state. If the drive state changes from the acceleration state to the constant speed state, the process proceeds to step S13.
Step S13 The cut condition fulfillment standby unit Pr3 waits for the lock signal to turn on. If the lock signal is turned on, the process proceeds to step S14.
Step S14 The cut condition fulfillment standby unit Pr3 determines whether or not the label paper P has slack. If slack is formed in the label paper P, the process proceeds to step S15, and if slack is not formed in the label paper P, the process proceeds to step S16.
Step S15 The slack forming unit Pr2 either keeps the feeding motor M1 and the conveying motor M2 in a constant speed state or decelerates them.
Step S16 The slack forming part Pr2 accelerates the feeding motor M1 and the conveying motor M2, and returns to step S14.
Step S17 The cutting position setting unit Pr4 sets the cutting position LA.
Step S18 The cut processor Pr5 determines whether or not the label paper P has slack. If the label paper P is slack, the process proceeds to step S19, and if the label paper P is not slack, the process returns to step S14.
Step S19 The cut processing unit Pr5 cuts the label paper P and ends the processing.

As described above, in the present embodiment, when the label paper P is already slack when the lock signal is turned on, the slack forming unit Pr2 causes the feed motor M1 and the transport motor M2 to operate at a constant speed. The label paper P is not excessively slackened because the label paper P is set to the state or decelerated.

Although the label paper printing apparatus 10 has been described in each of the above-described embodiments, the present invention can be applied to image forming apparatuses such as facsimiles and multi-function machines.

It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made based on the gist of the present invention, and they are not excluded from the scope of the present invention.

19 Delivery roller pair 20, 27 Transport roller pair 26 Cutter unit 48 Heating roller 49 Pressure rollers gr3 to gr6 Gear M1 Delivery motor M2 Transport motor M3 Fixing motor P Label paper Pr2 Looseness forming unit Pr5 Cut processing unit Rt1 Paper transport path

Claims (9)

(a) first and second drive sources;
(b) a first medium conveying member disposed in a medium conveying path, rotated by driving the first drive source, and conveying a medium;
(c) a second medium conveying member arranged downstream of the first medium conveying member in the medium conveying path, rotated by driving the second drive source, and conveying the medium;
(d) a rotation transmission system that transmits rotation of the first drive source to the first medium conveying member;
(e) a cutter unit arranged upstream of the second medium conveying member in the medium conveying path to cut the medium;
(f) when a predetermined time has passed since the overshoot caused by the drive of the second drive source was eliminated and the drive state transitioned from the acceleration state to the constant speed state, the 1, a slack forming unit that forms slack between the second medium transport members;
(g) a medium conveying device, further comprising a cut processing section that drives the cutter unit to cut the medium after slack is formed between the first and second medium conveying members. 2. The medium conveying device according to claim 1, wherein said second drive source is a DC motor. 3. The medium conveying device according to claim 1, wherein said first drive source is a stepping motor. The medium conveying device according to any one of claims 1 to 3, wherein the rotation transmission system is composed of a plurality of gears that are meshed with each other. 5. The predetermined time is set to a time required for absorbing backlash formed between gears of the rotation transmission system when overshoot occurs in the second drive source. A media transport device as described. The medium conveying device according to any one of claims 1 to 5, wherein the slack forming section forms slack in the medium by differentiating rotational speeds of the first and second drive sources. (a) a position detection unit that detects a predetermined portion of the medium in the medium transport path as a reference position;
(b) a cutting position setting unit that sets a cutting position of the medium based on the reference position; The medium conveying device according to any one of claims 1 to 7, wherein the cutter unit is a rotary cutter, and cuts the medium over a predetermined period of time. An image forming apparatus comprising the medium conveying device according to any one of claims 1 to 8.

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