JP2003327343A - Track control method and device for transport belt and printing method and device using them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-accuracy belt track control device and a printing device equipped with the track control device whereby the image formed on a work transported has less distortion owing to a track dislocation or speed change of a transport belt. <P>SOLUTION: The track control device for the transport belt is equipped with a track sensing means to acquire the track information of the transport belt, a pinching means to pinch the belt by its sides across the width using a track controlling contact, a means to adjust the pinching pressure, and a position adjusting means to move the belt in the axial direction of the contact while the belt is held pinched. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trajectory control device for correcting the trajectory of a transport mechanism such as a belt for transporting a work such as a printing device, a printing device having this trajectory control device, and a printing method.

[0002]

2. Description of the Related Art Conventionally, meandering of a belt for conveying a work,
As a belt trajectory control device for controlling the deviation, for example, as disclosed in Japanese Unexamined Patent Publication No. 09-48533, the position of the belt edge is detected, and according to the deviation amount from the reference position, Many trajectory control devices have been proposed in which the position of the belt is controlled by tilting the suspension roller of the belt.

As another method, there is a trajectory control device in which a suspension roller for suspending a belt is provided with a crown to control the position of the belt.

[0004]

However, in the above-mentioned prior art, the former is to control the position of the belt by inclining the belt suspension roller. In this method, when the control amount is large, There is a problem that wrinkles and floating occur, and when an image is formed on a conveyed work on the belt, the image is distorted.

Further, when the belt suspension roller is tilted, a load fluctuation is applied to the belt driving motor, which causes a speed fluctuation in the belt conveying direction, thus distorting an image on a workpiece conveyed on the belt. There is.

On the other hand, in the latter method of controlling the position of the belt by attaching a crown to the belt suspension roller, the belt has a shape following the crown, and the flatness of the belt is not sufficient, which is not suitable for image formation. There is a problem that it cannot be used.

The present invention has been made in view of the above prior art, and an object of the present invention is to provide an image formed on a workpiece to be conveyed with high accuracy and little distortion due to belt track deviation or speed fluctuation. It is an object of the present invention to provide a belt track control device and a printing apparatus equipped with this track control device.

[0008]

According to a first aspect of the present invention, there is provided a track control device for controlling a track of a conveyor belt on which a work is placed and which conveys the work, wherein a widthwise end portion of the conveyor belt is provided. Trajectory detecting means for obtaining trajectory information of the conveyor belt by detecting either the edge or the detection mark attached to the conveyor belt using a sensor, and sandwiching the conveyor belt from the front and back sides. The track control contact body to be attached is 1 or more on the front side and 1 on the back side of the conveyor belt.
Having the above, the sandwiching means for sandwiching both ends in the width direction of the transport belt by the track control contact body, and the pressure for sandwiching the transport belt by the transport belt sandwiching means in the width direction of the transport belt Pressure adjusting means for adjusting the one end side and the other end side so as to be equal or different, and the track control contact body of the sandwiching means, in the axial direction of the track control contact body while sandwiching the transport belt. Based on the information relating to the trajectory of the conveyor belt, which is detected by the trajectory adjusting means, the position adjusting means for moving along, the clamping pressure adjusting means and / or the position adjusting means are controlled. An adjusting mechanism control means for controlling a conveyor belt trajectory control device including the above.

According to a second aspect of the present invention, the pressure adjusting means localizes the distance between the track control contact bodies sandwiching the conveyor belt in a direction to locally approach or separate from each other.
In order to move the axis of the pressure roller, the actuator for acting on the trajectory control contact body or the support portion of the trajectory control contact body and adjusting the pressure for sandwiching the conveyor belt is used. It is the track control device for a conveyor belt according to claim 1.

According to a third aspect of the present invention, the track control contact body of the sandwiching means is a rotatable body that is rotatable while sandwiching the conveyor belt from the front and back sides. The track control device for a conveyor belt according to any one of 1 and 2.

According to a fourth aspect of the present invention, the track control contact body uses a roller arranged so as to extend across the width of the conveyor belt.
Orbital control device for the conveyor belt.

According to a fifth aspect of the present invention, in the trajectory detecting means, the sensor is arranged in the vicinity of the sandwiching means. It is a belt trajectory control device.

According to a sixth aspect of the present invention, in the trajectory detecting means, the sensor is arranged on the downstream side of the sandwiching means in the direction in which the conveyor belt is conveyed. 6. The trajectory control device for a conveyor belt according to any one of items 1 to 5.

According to a seventh aspect of the present invention, there is provided a drive roller for driving the conveyor belt, and an adjusting roller for adjusting the tension of the conveyor belt in a conveyor section for carrying and conveying the work. 7. The belt is an endless belt, and the pinching means is arranged in a section after passing through the conveying area and before being fed back to the adjusting roller. It is the orbital control device for the conveyor belt described in (1).

The invention according to claim 8 is a trajectory control method for controlling a trajectory of a conveyor belt on which a work is placed and which conveys the workpiece, which is an edge of a widthwise end portion of the conveyor belt or the conveyor. A trajectory information detection step of obtaining trajectory information of the conveyor belt by detecting any of the detection marks attached to the belt by using a sensor, and based on the trajectory information, the orientation of the trajectory of the conveyor belt is determined. When there is a tendency to change, the orbit control amount related to the widthwise both ends of the conveyor belt is made equal or different between one end side and the other end side, so that the conveyor belt conveys. Orbital control amount adjusting step for adjusting the inclination when the conveyor belt is moved toward the one side on the basis of the orbit information. To move to Adjustment step, a trajectory control method of the conveyor belt, characterized in that the above processes.

According to a ninth aspect of the present invention, there is provided a driving roller for driving the conveyor belt, and an adjusting roller for adjusting the tension of the conveyor belt in a conveyor section for carrying the workpiece on the conveyor belt. The belt is an endless belt, and the pinching means is arranged in a section after the transport belt has passed through the transport area and before being fed back to the adjusting roller. The method for controlling the orbit of the conveyor belt according to 1.

According to a tenth aspect of the present invention, the conveyor belt trajectory control device according to any one of the first to seventh aspects, a conveyance means using the trajectory control device, and a conveyance belt mounted and conveyed. A printing device comprising: a printing unit that prints on a recording medium that is a work based on the timing of the conveyance and image data.

An eleventh aspect of the present invention is the printing apparatus according to the tenth aspect, wherein the printing means uses an inkjet technique.

According to a twelfth aspect of the present invention, the conveyor belt can be electrically charged, and when the recording medium to be conveyed is a printing paper, the printing paper is charged by the electrification. The printing apparatus according to claim 10, wherein the printing apparatus can be temporarily fixed thereon.

According to a thirteenth aspect of the present invention, there is provided a step of conveying a recording medium by conveyance using the method for controlling the orbit of a conveyor belt according to any one of the eighth and ninth aspects. A printing method of performing printing on a recording medium to be performed based on the timing of the conveyance and image data, and the printing method.

According to a fourteenth aspect of the present invention, there is provided the printing method according to the thirteenth aspect, wherein an ink jet technique is used in the printing step.

According to a fifteenth aspect of the present invention, when the recording medium conveyed by the conveying belt is a printing sheet,
15. The printing method according to claim 13, wherein the printing paper is temporarily fixed so as to be attached to the transportation belt and then transported.

According to a sixteenth aspect of the present invention, the conveyor belt can be charged, and the printing paper is temporarily fixed on the conveyor belt by an electrostatic attraction force due to the charging. The printing method according to claim 15.

According to a seventeenth aspect of the present invention, the conveyor belt has a charging unit, a discharging unit, and a cleaning unit.
17. The printing method according to claim 16, wherein after the charging unit, the printing paper is conveyed and separated, and then the charge is removed, and then the cleaning unit removes dust on the belt.

According to the eighteenth aspect of the present invention, the conveying belt can be provided with suction holes for sucking air, and the printing paper is temporarily fixed to the conveying belt by an air suction force. The printing method according to claim 15, wherein the printing method is a printing method.

[0026]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings.

FIG. 1A is a perspective view showing an example of an embodiment according to the present invention, in which the orbit controller of the conveyor belt of the apparatus having a mechanism for conveying the recording medium (7) by the conveyor belt. It is about. The conveyor belt (6) is suspended around the drive roller (1a) and the back tension roller (4a). The transport belt (6) is nipped by the drive nip roller (1b) and the back tension nip roller (4b), respectively. In addition, between the drive roller (1a) and the back tension roller (4a), the trajectory control roller (1
4) and an orbit control idler roller (13) are provided and the conveyor belt (6) moves between these rollers.

The drive roller (1a) and the drive nip roller (1b) have sufficient rollers to prevent slippage due to the back tension force of the back tension roller (4a) generated by the back tension motor (5). The conveyor belt (6) is held under pressure. Also, these roller widths are narrower than the belt width,
The edges of the conveyor belt are not suspended on the ends of the rollers. This avoids damage to both the belt edge and the rollers.

The back tension roller (4a)
Like the drive roller (1a), the back tension nip roller (4b) holds the conveyor belt (6) with a sufficient roller pressure so that slip does not occur due to the back tension force. Further, the roller width is narrower than the belt width, and the edge of the conveyor belt is prevented from hanging on the roller end to avoid damage to both the belt edge and the roller. Further, the back tension force is variable according to the type of the conveyor belt.

The upper side of the conveyor belt (6) is the image forming section (10) side, and the recording medium (7) is conveyed using the upper surface of the conveyor belt. Therefore, in order to secure the flatness and suppress the vertical movement during the conveyance, a tension according to the type of the conveyance belt is applied. Further, as shown in FIG. 1B, no tension is applied to the lower side of the belt, and both sides of the track control roller (14) are slightly slackened. As a result, the belt trajectory control can be easily performed without restraint by the tension, and the deformation of the belt caused by the trajectory control stays in the slack portion (11) and does not affect the image forming portion (10). In addition, since tension is not applied, speed fluctuation due to load fluctuation caused by trajectory control also causes slack (11).
Can be absorbed into. Here, the recording medium (7) is
In the case of printing paper, fixing to the transport belt may be carried by either a method of electrostatically attracting by charging the transport belt or a method of providing suction holes in the belt and sucking with air.

FIG. 2 shows the trajectory control roller (14) of FIG.
The part is shown, and the conveyor belt track controller of the conveyor belt track controller is shown. As is clear from the figure,
Position sensor for detecting belt position (15)
(16) and a trajectory control roller (14) for controlling the trajectory of the conveyor belt (6), and the conveyor belt (6) is moved along the axial direction of the trajectory control roller (14) while sandwiching the conveyor belt (6). It is composed of a position adjusting mechanism.

The sensor for detecting the position of the conveyor belt is
Two transmissive optical sensors are provided downstream of the orbit control roller (14) and have a light projecting section and a light receiving section. With this, vertical belt movement and belt color influence are small and accurate. The position of the belt can be detected.

Further, as shown in FIGS. 1A and 1B, the paper leading edge position detection sensor (9) is provided in the vicinity of the entrance of the conveyor belt and detects the leading edge position of the recording medium (7). , Print timing is controlled by the inkjet head (12), and image data is printed.

The trajectory control roller (14) and the trajectory control idler roller (13) are rotating bodies having no rotational force. Further, one of the pair of rollers has a shape in which the diameter on both ends of the belt is large and the diameter on the side near the center of the belt is small so that it does not contact the belt. As a result, the pressure applied to the roller concentrates on both ends, so that control can be performed efficiently. Here, the orbit control roller, if it can be rotated while sandwiching the conveyor belt, not only the rollers straddling the conveyor belt but also the rotating wheel and the roller that sandwiches only the belt both ends, or only the belt both ends. It does not matter even if the rotating wheels are sandwiched. Also,
The roller width is narrower than the belt width, and the edge of the belt does not hang on the end of the roller to avoid damage to both the belt edge and the roller.

The orbit control roller (14) has actuators (17) and (18) for pressurizing and depressurizing, respectively.
It is arranged at both ends of the roller. The actuators (17) (18) include position sensors (15) (1
The belt inclination can be controlled by making the roller pressures at both ends equal or different based on the trajectory information from 6). At this time, the conveyor belt (6) is deformed by the trajectory control, but this deformation is retained in the slack portion (11) upstream and downstream of the trajectory control roller (14) and does not affect the image forming unit (10). . Further, not only the shaft ends on both sides of the track control roller (14) but also the shaft ends on both sides of the track control idler roller (13) or the track control roller (1
4) and the orbit control idler roller (13) may be shaft ends on both sides. The means for sandwiching the belt is
If it is not a roller that straddles the belt but a rotating wheel that sandwiches only both ends of the belt, the shaft ends on the front side of the conveyor belt, the shaft ends on the back side of the conveyor belt, and the shafts on both the front and back sides of the conveyor belt. It doesn't matter if it's on the edge.

Further, the position adjusting mechanism can move the orbit control rollers (13) and (14) along the axial direction while sandwiching the belt. At this time, the transport belt (6) is deformed by the trajectory control, and this deformation is caused by the slack (11) upstream and downstream of the trajectory control roller (14).
It does not affect the image forming unit (10).

FIG. 3 is an explanatory view showing the roller pressure and the movement of the belt. The roller pressure on the left side (PAL) and the roller pressure on the right side (PAR) are equal, as shown in FIG.
In the case of L = PAR), the belt advances in a direction perpendicular to the roller, and the roller pressure on the left side is higher than that on the right side.
In the case of (PAL> PAR), the belt leans to the left while tilting counterclockwise. In the case of FIG. 3C (PAL <PAR>) where the roller pressure on the right side is higher than that on the left side, the belt leans toward the right side while inclining clockwise.

FIG. 4 is an explanatory diagram showing a control sequence of the conveyor belt trajectory control device of the present invention. First, the position adjusting mechanism moves the edge of the conveyor belt (6) to the center (PS1 = 0) of the position sensors 1 (PS1) (15). Next, position sensor 2 (PS2)
From the trajectory information of (16), the belt edge position is on the right side (P2) with respect to the center of the position sensor 2 (PS2 = 0).
If S2> 0), the left roller pressure (PAL)
Is reduced, and the roller pressure (PAR) on the right side is increased. The position of the belt edge is the position sensor 2
When it is in the center (PS2 = 0), the left and right roller pressures are kept as they are, and the left side of the position sensor 2 (PS
When 2 <0), the roller pressure (PAR) on the left side is increased and the roller pressure (PAR) on the right side is reduced. Since the above control is performed while the conveyor belt (6) is being conveyed, the edge of the position sensor 1 (P
It may deviate from the center of S1) (PS = 0). Therefore, the amount of deviation between the edge and the center (PS1 = 0) is recognized from the trajectory information of the position sensor 1 (PS1), and the amount is shifted to the right (PS2> 0) by ΔΔstep by the position adjustment mechanism motor (23). If they are deviated, the edge is made the center (PS1 = 0) of the position sensor 1 (PS1) by moving ΔΔstep to the left. Similarly, when the edge is deviated from the center (PS = 0) of the position sensor 1 (PS1) to the left (PS1 <0) by ΔΔstep, the edge is moved to the right ΔΔstep to move the edge to the position sensor 1 (PS1). The center of (PS1) (PS1 = 0) is set. By repeating these controls, the position and inclination of the conveyor belt can be controlled. A stepping motor (SMO) can be used as the position adjusting mechanism motor (23), but the present invention is not limited to this as long as the effect of the present invention is exhibited.

[0039]

【The invention's effect】

As described above, according to the present invention, since wrinkles and floating due to the trajectory control of the conveyor belt do not occur, and there is no speed fluctuation due to the trajectory control, the fluctuation caused by the trajectory control is the cause. The effect is that image distortion is eliminated.

Further, in the conveyor belt trajectory control device of the present invention, since the highly accurate conveyance range is obtained as a flat surface, for example, in addition to printing by one row of inkjet heads,
It is also possible to print with an inkjet head in which a plurality of heads are two-dimensionally arranged.

Further, since it is possible to cope with changes with time of the device parts and the conveyor belt, there is an effect that stable operation can be performed for a long period of time.

Further, the conveyor belt trajectory control device of the present invention may be used with a belt having a slightly different peripheral length at both ends of the belt, and further, the alignment adjustment range of the roller at the time of manufacturing the device can be widened. It is possible, and the economic effect and the reduction of work load can be expected.

[Brief description of drawings]

FIG. 1 is a schematic perspective view illustrating an example of a conveyor belt trajectory control device according to the present invention.

FIG. 2 is a perspective view of a schematic belt track control unit illustrating an example of a conveyor belt track control device according to the present invention.

FIG. 3 is a diagram showing the roller pressure and the movement of the belt of the conveyor belt trajectory control device according to the present invention.

FIG. 4 is a diagram showing a control sequence for explaining an example of a conveyor belt trajectory control device according to the present invention.

[Explanation of symbols]

1a ... Drive roller 1b ... Drive nip roller 2 ... Drive motor 3 ... Encoder 4a ... Back tension roller 4b ... Back tension nip roller 5 ... Back tension motor 6 ... Transport belt 7 ... Recording medium 8: Transport direction 9: Paper edge position detection sensor 10 ... Image forming unit 11 ... slack section 12 ... Inkjet head 13 ... Orbit control idler roller 14 ... Orbital control roller 15: Position sensor 1 (PS1) 16: Position sensor 2 (PS2) 17: Actuator 18 ... Actuator 19: Roller support 20 ... Roller support 21 ... Pressurization 22 ... decompression 23 ... Position adjustment mechanism motor 24: Transport direction 25: Position adjustment mechanism limit switch 26: Position adjustment mechanism limit switch

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B41J 29/17 B65H 5/22 C B65H 5/00 7/20 B41J 3/04 101Z 5/22 29/00 S 7/20 JF Term (reference) 2C056 EA04 EB12 EC12 EC32 HA29 HA31 JB18 2C061 AQ05 CM03 CP03 3F048 AA05 AB01 BA20 BB05 CC05 DC13 EB25 EB39 3F049 AA02 BA04 BB11 DB04 DB05 FB00 LA07 LA03 3F101 AB

Claims (18)

[Claims] 1. A trajectory control device for controlling a trajectory of a conveyor belt on which a work is placed and which conveys the workpiece, the detection being performed at an edge of a widthwise end portion of the conveyor belt or on the conveyor belt. Trajectory detection means for obtaining trajectory information of the conveyor belt by detecting any of the marks by using a sensor, and a trajectory control contact body that sandwiches the conveyor belt from the front and back sides, the front side of the conveyor belt. 1 or more on the back side and 1 or more on the back side, and sandwiching means for sandwiching both end sides in the width direction of the transport belt by the track control contact body, pressure for sandwiching the transport belt by the transport belt sandwiching means, Pressure adjusting means for adjusting the one end side and the other end side in the width direction of the conveyor belt so as to be equal or different from each other; and the track control contact body of the nipping means while nipping the conveyor belt. Position adjusting means for moving along the axial direction of the track control contact body, based on the information on the track of the conveyor belt detected by the track detecting means, between the pinching pressure adjusting means and the position adjusting means. An orbital control device for a conveyor belt, comprising: an adjusting mechanism control means for controlling either or both of them. 2. The pressure adjusting means locally reduces the distance between the track control contact bodies sandwiching the conveyor belt,
Alternatively, in order to move the axis of the pressure roller in the direction of separating, use an actuator that acts on the track control contact body or a support portion of the track control contact body and adjusts the pressure for pinching the conveyor belt. The trajectory control device for a conveyor belt according to claim 1, wherein: 3. The track control contact body of the pinching means,
3. The trajectory control device for a conveyor belt according to claim 1, wherein the conveyor belt is a rotatable body that can rotate while sandwiching the conveyor belt from the front and back sides. 4. The conveyor belt according to claim 1, wherein the track control contact body is a roller arranged so as to extend in the width direction of the conveyor belt. Orbit control device. 5. The track control device for a conveyor belt according to claim 1, wherein the track detection means has the sensor arranged near the sandwiching means. 6. The track detecting means according to claim 1, wherein the sensor is arranged on the downstream side of the sandwiching means in the direction in which the conveyor belt is conveyed. Trajectory control device for conveyor belts. 7. A drive roller for driving the conveyor belt,
An adjustment roller is provided for adjusting the tension of the conveyor belt in the conveyor section where the work is placed and conveyed, and the conveyor belt is an endless belt and is sent back to the adjustment roller after passing through the conveyor area. Within the section up to
7. The conveyor belt trajectory control device according to claim 1, wherein the pinching means is provided. 8. A trajectory control method for controlling a trajectory of a conveyor belt on which a workpiece is placed and conveys the workpiece, the edge of a widthwise end portion of the conveyor belt, or a detection mark attached to the conveyor belt. A trajectory information detecting step of obtaining trajectory information of the conveyor belt by detecting one of the following using a sensor; and when the orientation of the trajectory of the conveyor belt tends to change based on the trajectory information, Adjusting the inclination of the conveyor belt when the conveyor belt is conveyed by equalizing or differentiating the orbit control amount on both ends in the width direction of the conveyor belt between one end side and the other end side. An orbital control amount adjusting step of performing a position adjusting step based on the orbital information, when the orbit of the conveyor belt is shifted to one side as a whole, the entire conveyor belt is moved in the opposite direction to the side closer to the one side, The above steps Track control method of the conveyor belt, characterized in that to go through. 9. A drive roller for driving the conveyor belt,
An adjusting roller for adjusting the tension of the conveyor belt in a conveyor section for carrying the work is provided, the conveyor belt is an endless belt, and the adjusting roller after the conveyor belt has passed through the conveyor area. 9. The trajectory control method for a conveyor belt according to claim 8, wherein the pinching means is arranged in a section until it is sent back to the conveyor belt. 10. A conveyor belt trajectory control device according to any one of claims 1 to 7, a conveyor means using the trajectory control device, and a recording work which is a work carried on the conveyor belt. A printing apparatus comprising: a printing unit that prints on a medium based on the conveyance timing and image data. 11. The printing apparatus according to claim 10, wherein the printing means uses an inkjet technique. 12. The transport belt can be electrically charged, and when the recording medium to be transported is a printing paper, the printing paper can be temporarily fixed on the transportation belt by the charging. The printing device according to claim 10, wherein the printing device is a printing device. 13. A step of transporting a recording medium by transport using the method for controlling the trajectory of a transport belt according to claim 8 or 9, wherein the recording medium carried on the transport belt is transported. A printing step of performing printing based on the conveyance timing and image data, and a printing method characterized by the above. 14. The printing method according to claim 13, wherein an inkjet technique is used in the printing step. 15. When the recording medium conveyed by the conveying belt is a printing sheet, the printing sheet is temporarily fixed and conveyed so as to adhere to the conveying belt. Or the printing method according to any one of 14 above. 16. The printing according to claim 15, wherein the conveyor belt is chargeable, and the printing paper is temporarily fixed on the conveyor belt by an electrostatic attraction force due to the charging. Method. 17. The conveying belt has a charging unit, a discharging unit, and a cleaning unit, and after the charging unit, the printing paper is conveyed and separated, and then the charging unit is decharged, and then the cleaning unit puts the belt on the belt. The printing method according to claim 16, wherein dust is removed. 18. The conveyor belt for adsorbing air,
16. The printing method according to claim 15, wherein suction holes can be formed, and the printing paper is temporarily fixed to the conveyor belt by an air suction force.