JP4609022B2 - Conveying device and printing equipment - Google Patents

Description

  The present invention relates to a conveyance device and a printing device, and more particularly to a configuration of a conveyance device and a printing device that are suitable when a conveyance body including a conveyance belt is included.

  2. Description of the Related Art Conventionally, a printing apparatus including a conveyance belt is known for conveying a printing material such as paper. As shown in FIGS. 8 and 9, this type of printing apparatus 300 includes a conveyance belt 340 that is movably stretched around conveyance rollers 344, 345, and 346, and a conveyance roller 344 that rotates to convey the conveyance belt 340. A driving motor 342 to be operated, a driving circuit 343 for driving the driving motor 342, a gate driving roller 320 and a gate driven roller 321 for sending the paper P to the transport belt 340, a driving motor 322 for rotationally driving the gate driving roller 320, and this A drive circuit 323 that drives the drive motor 322 and a print head 360 that prints on the paper P disposed on the transport belt 340 are included. Here, the print head 360 is, for example, an ink jet head configured to be able to eject ink droplets. A printing apparatus including such a transport mechanism is described in, for example, Patent Document 1 below.

  In addition, a linear encoder detected band 340a in which a large number of detected elements such as slits are arranged at equal intervals in the conveying direction F along one side end of the conveying belt 340 is provided. The linear encoder 348 is detected by the linear encoder 348, and the detection signal is supplied to the control unit 362. Further, an origin (tab) 340b is provided at a side end of the conveyor belt 340, and the origin detector 349 is configured to detect the origin 340b.

  Furthermore, as shown in FIG. 10, the control unit 362 is provided with a main control unit 440, a timing signal generation circuit 460, and a head drive circuit 480. Here, the timing signal generation circuit 460 generates a timing signal ST based on the detection signal S1 of the linear encoder 348, and the head driving circuit 480 generates the timing signal ST based on the timing signal ST and print data supplied from the main control unit 440. Is generated and supplied to the print head 360. In the print head 360, in response to the drive signal SD, for example, an ink ejection element such as a piezo element provided inside operates to eject ink droplets. Note that a printing apparatus having the same configuration is described in Patent Document 2 below.

In the printing apparatus 300, first, the motor 342 is operated by the drive circuit 343, the conveyance roller 344 is rotationally driven, and the conveyance surface of the conveyance belt 340 moves in the conveyance direction F. Next, the paper P is supplied by a paper feeding mechanism (not shown), the leading edge of the paper P abuts between the stationary gate driving roller 320 and the gate driven roller 321, and skew correction is performed on the paper P. In addition, the leading edge of the paper P is positioned. The origin (tab) 340b is detected by the origin detector 349 and the movement amount of the conveyor belt 340 is detected by the linear encoder 348, whereby the absolute position of the conveyor belt 340 is measured. Then, at a predetermined timing when the measured absolute position of the conveyor belt 340 becomes a predetermined value, the motor 322 starts to rotate the gate driving roller 320, and the paper P passes between the gate driving roller 320 and the gate driven roller 321. It is sent out onto the conveyance surface of the conveyance belt 340. Here, the paper P is adsorbed on the conveyance surface of the conveyance belt 340 by negative pressure generated by forming an air flow with a suction fan or the like inside the conveyance belt 340 or static electricity generated by applying a high voltage to the conveyance belt. Is done. Then, when the portion of the paper P that is present on the conveying belt 340 and adsorbed by the gate driving roller 320 and the gate driven roller 321 becomes longer to some extent, the gate driving roller 320 is separated from the paper P, and the paper P It is transported only by the transport belt 340. When this happens, the print head 360 is controlled by the control unit 362 according to the amount of movement detected by the linear encoder 348, and printing is performed on the paper P.
JP-A-2-187355 JP 2004-17458 A

  However, in the printing apparatus 300 described above, it is necessary to feed the paper P onto the transport surface by the gate driving roller 320 and the gate driven roller 321 until the paper P is sufficiently sucked and held by the transport surface of the transport belt 340. Therefore, it is necessary to secure a certain distance between the gate driving roller 320 and the gate driven roller 321 and the print head 360. That is, the travel distance of the paper P from the start of the feeding of the paper P by the gate driving roller 320 and the gate driven roller 321 to the separation of the gate driving roller 320 from the paper P is required in addition to the printing area.

  In particular, if the adsorption force of the conveyance belt 340 with respect to the paper P is weak, the movement amount of the conveyance belt 340 and the movement amount of the paper P indicated by the detection signal S1 of the linear encoder 348 due to the paper P slipping with respect to the conveyance belt 340 or the like. Are not matched and the above-mentioned attractive force may be lowered with a lapse of time. Therefore, in order to ensure print quality, it is necessary to set the above distance with a certain margin.

  Therefore, in the prior art, it is necessary to ensure the size of the apparatus along the transport direction F more than the printing range, so there is a problem that it is difficult to reduce the size of the apparatus, and it is also attempted to reduce the size of the apparatus. In this case, there is a possibility that the print quality is lowered, and further, if the suction means is increased in order to increase the suction force of the transport belt 340, there is a problem that the manufacturing cost is increased.

  Therefore, the present invention solves the above-described problems, and the problem is to realize a configuration capable of reducing useless space in the transport direction while ensuring appropriate position detection within a predetermined range. It is an object of the present invention to provide a transport device that can be reduced in size and a printing apparatus including the transport device.

  The transport apparatus according to the present invention includes a transport body configured such that a transport surface for transporting a transported material is movable, a delivery mechanism for sending the transported material onto the transport surface, and an amount of movement of the transport surface A first detector that detects the amount of the material to be conveyed by the delivery mechanism, and a detection signal from the first detector when the material to be conveyed is moved by the conveyance body. And a signal switching means for outputting a detection signal of the second detector when the transported material is moved by the delivery mechanism.

  According to this invention, it is possible to know the amount of movement of the material to be conveyed arranged on the conveyance surface by detecting the amount of movement of the conveyance surface of the conveyance body with the first detector, and the conveyance by the delivery mechanism. By detecting the material feed amount with the second detector, it is possible to know the amount of movement of the transported material even in the process of feeding the transported material onto the transport surface by the feed mechanism. Since the detection signal of the first detector and the detection signal of the second detector can be switched by the signal switching means, the output of the second detector is supplied when the transported material is sent out by the delivery mechanism. By supplying the output of the first detector when the transport material is moving by the transport body, it is always possible to check the transport material regardless of whether the transport material is transported by the delivery mechanism or the transport body. The amount of movement can be known appropriately. Therefore, in the case where some processing is performed on the material to be conveyed, not only the period during which the material to be conveyed is conveyed by the conveyance body but also the period during which the material to be conveyed is sent out on the conveyance surface by the delivery mechanism. Since the processing can be performed while grasping the position of the transport material, the length of the transport body in the transport direction can be reduced, and the apparatus can be downsized.

  In the present invention, it further comprises a separating / contacting means for separating and contacting the delivery mechanism with respect to the material to be conveyed, and the signal switching means is synchronized with a separation timing of the delivery mechanism with respect to the material to be conveyed by the separation / contacting means. Preferably, the detection signal of the second detector is switched to the detection signal of the first detector. According to this, after the transported material is sent out on the transport surface of the transport body by the feed-out mechanism, the transport mechanism is separated from the transported material at a predetermined timing, thereby transporting the transported material from the transporting process of the transport mechanism. It is possible to make an instant and reliable transition to the transport process of the transported material by the body, but by operating the signal switching means in synchronization with this transition timing, the amount of transport of the transported material can be accurately determined. I can know. In this case, by operating the signal switching means using the separation timing signal for operating the contact / separation means, it is possible to avoid complication of the control system and to improve the time accuracy of the signal switching timing.

  In the present invention, it is preferable to further comprise output matching means for matching the detection signal of the first detector and the detection signal of the second detector. According to this, since the detection signal of the first detector and the detection signal of the second detector do not have to be matched by providing the output matching means, the structure of the first detector and the second detector If the phase of both detection signals needs to be matched as well as the degree of freedom of the detection location increases, the phase of both detection signals should be matched by the output matching means. As a result, the adjustment work during the installation of the first detector and the second detector becomes unnecessary. The output matching means may be any means that can match both detection signals in a manner according to how the detection signals are used. For example, the output matching means may be a means for matching only the period between the two detection signals. It may be a means for matching only the phase between the two detection signals.

  In the present invention, the output matching means is preferably composed of an output conversion circuit that converts one of the detection signal of the first detector and the detection signal of the second detector so as to match the other. . According to this, since either one of the two detection signals is matched to the other by the output conversion circuit, when adding the other detector to the existing configuration including one detector, the existing one This makes it possible to cope with the present invention without changing any of the detectors and the control unit, which is advantageous in terms of cost.

  In the present invention, the output matching means is preferably means for matching the phase and period of the detection signal of the first detector and the detection signal of the second detector. Since both the phase and period of both detection signals are matched by the output matching means, an output can be obtained continuously even when the signal is switched by the signal switching means. It can be avoided that the position detection value of the material to be conveyed becomes discontinuous when the material to be conveyed is shifted to the conveyance process.

  Next, the printing apparatus according to the present invention includes a transport body configured to be able to move a transport surface for transporting the transported material, a delivery mechanism for sending the transported material onto the transport surface, and the transported material. Printing means for printing on the material, a detector for detecting the amount of the transported material delivered by the delivery mechanism, and a print control means for controlling the printing means based on a detection signal of the detector. It is characterized by that.

  According to this invention, while the transported material is being sent out on the transport surface of the transport body by the sending mechanism, the printing control means is based on the detection signal of the detector that indicates the feed amount of the transported material by the sending mechanism. By controlling the printing unit, the printing unit can perform printing on the transported material in a mode corresponding to the position of the transported material. Since printing is performed even in the process in which the material to be transported is transported to the transport surface by the transport mechanism in this way, it is not necessary to secure the distance between the transport mechanism and the print position, and as a result, extra dimensions in the transport direction. By reducing this, it is possible to reduce the size of the printing device.

  Another printing apparatus of the present invention includes a transport body configured such that a transport surface for transporting a transported material is movable, a delivery mechanism that sends the transported material onto the transport surface, and the transported material. The printing means for printing on the transport material, the first detector for detecting the amount of movement of the transport surface, the second detector for detecting the transport amount of the transported material by the feed mechanism, and the transport body A signal switching means for outputting a detection signal of the first detector when the conveyed material moves, and a signal switching means for outputting a detection signal of the second detector when the conveyed material is moved by the sending mechanism; and the signal switching Printing control means for controlling the printing means based on the output of the means.

  According to the present invention, in the process in which the transported material is being sent out on the transport surface of the transport body by the sending mechanism, printing is performed based on the detection signal of the second detector that indicates the feed amount of the transported material by the sending mechanism. When the control unit controls the printing unit, the printing unit can perform printing on the transported material in a manner corresponding to the position of the transported material. Further, in the process in which the transported material is moved by the transport body after being sent out by the feed mechanism, the print control means controls the printing means based on the detection signal of the first detector indicating the amount of movement of the transport surface, so that the printing means However, printing can be performed on the material to be conveyed in a manner corresponding to the position of the material to be conveyed. Therefore, printing can be performed according to the position of the transported material both in the process of feeding the transported material by the transporting mechanism and in the process of moving the transported material by the transporting body, ensuring the distance between the transporting mechanism and the printing position. As a result, it is possible to reduce the size of the printing apparatus by reducing extra dimensions in the transport direction.

  In the present invention, it further comprises a separating / contacting means for separating and contacting the delivery mechanism with respect to the material to be conveyed, and the signal switching means is synchronized with a separation timing of the delivery mechanism with respect to the material to be conveyed by the separation / contacting means. Preferably, the detection signal of the second detector is switched to the detection signal of the first detector.

  In the present invention, it is preferable to further comprise output matching means for matching the detection signal of the first detector and the detection signal of the second detector.

  In the present invention, the output matching means is preferably composed of an output conversion circuit that converts one of the detection signal of the first detector and the detection signal of the second detector so as to match the other. .

  In the present invention, the output matching means is preferably means for matching the phase and period of the detection signal of the first detector and the detection signal of the second detector.

  When the phases of both detection signals are matched in the output matching means, a phase delay circuit that delays the phase of one of the detection signals can be used. Further, when the period of one detection signal is a natural number multiple of the period of the other detection signal, a multiplier circuit or a frequency divider circuit can be used to match the periods of both detection signals. Even when the cycle of one detection signal is not a natural number multiple of the cycle of the other detection signal, it is possible to obtain mutually matching cycles by combining a multiplier circuit and a frequency divider circuit.

  The delivery mechanism may be any mechanism as long as it feeds the transported material toward the transport surface of the transport body. For example, a roller that feeds the transported material and rotationally drives the roller. It is possible to provide a means for performing. Examples of the roller include a gate roller having a function of positioning a material to be conveyed. Further, as the gate roller, there is a feeding mechanism including a gate driving roller and a gate driven roller that feeds out the conveyed material, and in this case, the separation / contact means is one of the gate driving roller and the gate driven roller. May be configured to be separated from the material to be conveyed. Here, it is preferable that one of the gate driving roller and the gate driven roller is made of a hard material that does not deform, and the other roller is made of a material that elastically deforms. At this time, it is desirable that the detector for detecting the amount of the material to be conveyed by the delivery mechanism detects the amount of rotation of the one roller. In the present invention, any detector can be used as long as it can detect the delivery amount of the material to be conveyed by the delivery mechanism as a detector for detecting the delivery amount by the delivery mechanism.

  Next, embodiments of a transport device and a printing apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic diagram in which a block diagram showing a configuration of a control system is added to a schematic plan view schematically showing a printing apparatus including a transport apparatus according to an embodiment of the present invention. The printing apparatus 100 includes a gate driving roller 120 and a gate driven roller 121 that constitute a feeding mechanism for feeding the paper P that is a material to be conveyed, and a conveying belt disposed on the feeding side of the gate driving roller 120 and the gate driven roller 121. And a transport device having a transport body having 140.

  The gate driving roller 120 and the gate driven roller 121 are pivotally supported so as to be rotatable around mutually parallel axes at a position adjacent to one end side of the conveyance body. The gate driving roller 120 and the gate driven roller 121 are for correcting the skew feeding of the paper P supplied by a paper feeding mechanism (not shown) of the printing apparatus 100 and feeding the paper P onto the conveying belt at a predetermined timing. It is.

  The outer peripheral surface of the gate driving roller 120 is a cylindrical surface, and is configured not to be substantially deformed when the paper P is fed out. That is, the gate driving roller 120 is made of a hard material that does not deform in operation, and is made of metal, for example. A driving shaft of a motor 122 is connected to one end (left side in FIG. 1) of the gate driving roller 120, and the gate driving roller 120 is driven to rotate by the motor 122. The motor 122 is driven by a drive circuit 123.

  The gate follower roller 121 has a cylindrical outer peripheral surface like the gate drive roller 120, but is configured to be elastically deformable at least in the radial direction. For example, the main body of the gate driven roller 121 is made of rubber or soft synthetic resin. As shown in FIG. 2A, even when the paper P is not interposed between the gate driving roller 120 and the gate driven roller 121, the outer peripheral surface of the gate driving roller 120 and the outer peripheral surface of the gate driven roller 121 are in contact with each other. In contact with each other, there is no gap between the two outer peripheral surfaces to allow the paper P to pass therethrough. In this case, it is preferable that the contact portion of the gate driven roller 121 is somewhat elastically deformed in order to reliably eliminate the gap. As described above, since there is no gap between the outer peripheral surfaces even when the paper P is not interposed, the gate driving roller 120 and the gate which are stationary at the leading edge of the paper P supplied by a paper feeding mechanism (not shown) or the like. It is possible to abut against the contact portion of the driven roller 121, thereby correcting the skew of the paper P and positioning the leading edge of the paper P.

  Further, as shown in FIG. 2B, when the paper P is fed out by the gate drive roller 120 that is driven to rotate, the outer peripheral surface of the gate drive roller 120 is not deformed, and the outer peripheral surface of the gate driven roller 121 is not deformed. The paper P is pushed between the two outer peripheral surfaces while being elastically deformed. Here, the contact area between the paper P and the gate driving roller 120 and the gate driven roller 121 is increased, the paper P is less likely to slip, and the outer peripheral surface of the gate driving roller 120 is not deformed as described above. Therefore, the rotation amount of the gate driving roller 120 and the delivery amount of the paper P are proportional to each other with high accuracy. When the leading edge of the paper P is positioned between the stationary gate driving roller 120 and the gate driven roller 121, the gate driving roller 120 starts to rotate and the paper P is sent out. As the gate driven roller 121 is further deformed by the thickness of the paper P, the feeding is started smoothly.

  In the present embodiment, a rotary encoder 125 that is the second detector described above is provided to detect the amount of rotation of the gate drive roller 120. The rotary encoder 125 includes, for example, a detected portion 125a configured by a disk or the like in which detected elements configured by a large number of slits or the like are formed at equal intervals around the rotation axis, and the detected portion 125a. It is comprised by the detection part (sensor) 125b which can detect a to-be-detected element. In the illustrated example, the detected portion 125a is connected and fixed so as to rotate together with the gate drive roller 120, and the detecting portion 125b is fixed to a frame or the like (not shown). A transmissive optical sensor or the like can be used as the detection unit 125b. However, the rotary encoder 125 is not limited to this, and a rotary optical sensor or a magnetic sensor may be used.

  Next, the conveyance belt 140 is an annular belt having a predetermined width, and is stretched around the driving roller 144, the driven roller 145, and the tension roller 146 so as to be able to run. The drive roller 144 is connected to a motor 142 controlled by a drive circuit 143, and moves the transport surface of the transport belt 140 toward the transport direction F. The driven roller 145 is rotatably supported, and is driven to rotate when the rotation of the driving roller 144 is transmitted through the conveyor belt 140. The tension roller 146 is rotatably supported so as to apply a constant tension to the transport belt 140.

  In the present embodiment, it is preferable to provide an adsorption force generating means for adsorbing the paper P on the conveyance surface of the conveyance belt 140. It is possible to move the paper P together with the conveyance surface of the conveyance belt 140 by a frictional force generated between the paper P and the conveyance belt 140 without separately providing the adsorption force generation means. By providing, the positional deviation of the paper P can be prevented more reliably, and the conveyance accuracy and printing accuracy of the paper P can be improved. Such an adsorption force generating means is known, for example, a configuration in which a voltage application circuit for generating an electrostatic force is generated by charging the conveyor belt 140, and a large number of minute holes are formed in the conveyor belt. Examples include a configuration in which a negative pressure is generated by generating an air flow with a suction fan or the like inside the erection portion of the conveyor belt.

  At one side end of the conveyor belt 140, a detected part 148a in which detected elements such as a number of slits are arranged at equal intervals in the conveying direction F, and the detected element of the detected part 148a are placed at predetermined positions. A linear encoder 148 having a detecting unit 148b for detecting at 155 is provided. As the detected portion 148a, a detection band in which light transmission portions and light shielding portions are alternately arranged as detection elements can be used fixed to the side end portion of the conveyor belt 140, and the detection portion 148b can transmit light. Type optical sensors can be used. However, the linear encoder 148 is not limited to this, and may use a reflective optical sensor or a magnetic sensor.

  In addition, an origin (tab) 140b is provided at the other side end of the conveyor belt 140, and an origin detector 149 configured to be able to detect the origin 140b is provided. From the origin detection signal output from the origin detector 149 and the detection signal output from the linear encoder 148, the absolute position of the transport surface of the transport belt 140 can be known.

  The print head 160 of the present embodiment may be anything as long as it can print on the paper P, which is a transported material. For example, an ink storage unit provided with an ejection port at the bottom of the head, and the ink storage One having an ink discharge portion provided with a piezo element for changing the volume of the portion. In the case of the illustrated example, the print head 160 has a plurality of the ink ejection units arranged in a direction orthogonal to the transport direction F. Then, the piezoelectric element is deformed based on a drive signal SD, which will be described later, and the volume of the ink containing portion is reduced, whereby ink droplets are ejected from the ejection ports and land on the paper P.

  In the present embodiment, the drive circuits 123 and 143, the linear encoder 148, the origin detector 149, the rotary encoder 125, and the print head 160 are connected to the control unit 162. The control unit 162 controls the entire apparatus while receiving signals such as detection signals from the above-described units. FIG. 3 is a schematic configuration diagram schematically showing the internal configuration of the control unit 162.

  As shown in FIG. 3, the control unit 162 includes a main control unit 180 configured by an MPU (Micro Processing Unit) and the like, an output conversion circuit 220 that converts the detection signal S <b> 2 of the rotary encoder 125, and a linear encoder 148. A signal changeover switch 240 that switches and outputs either the detection signal S1 or the correction signal SC output from the output conversion circuit 220, and a timing signal generation circuit 260 that receives the output of the signal changeover switch 240 and generates a timing signal ST. And a head drive circuit 280 that forms a drive signal SD based on the timing signal ST and a control signal or print data supplied from the main control unit 180 and supplies the drive signal SD to the print head 160.

  The main controller 180 receives the origin detection signal S0 output from the origin detector 149 and supplies a control signal to the drive circuits 123 and 143. Further, in this embodiment, a roller separation drive unit for setting the position of the gate drive roller 120 to either a position in contact with the passage trajectory of the paper P or a position separated from the passage trajectory. 151 is provided, and the main control unit 180 sends a separation timing signal SQ to the roller separation / contact driving unit 151.

  The output conversion circuit 220 matches the detection signal S2 of the rotary encoder 125 with the detection signal S1 of the linear encoder 148. In the case of the illustrated example, the output conversion circuit 220 includes a phase delay circuit 222 and a period matching circuit 224, and is configured to convert the detection signal S2 into a correction signal SC whose phase and period match with the detection signal S1. ing. Here, the phase delay circuit 222 measures the phase difference between the detection signals S1 and S2 at a certain point in time, and corrects the phase of the detection signal S2 by this phase difference and outputs the phase delay signal SB whose phase matches the detection signal S1. Then, the phase delay signal SB is multiplied or divided by the period matching circuit 224 to be converted into the correction signal SC having the same period as that of the detection signal S1.

  More specifically, the correction signal SC whose phase and period are matched with the detection signal S1 is when the rotational speed of the gate driving roller 120 is always completely coincident with the moving speed of the conveying surface of the conveying belt 140. , A signal whose phase and period completely coincide with the detection signal S1. That is, in the output matching circuit 220, when the rotational speed of the gate driving roller 120 and the moving speed of the transport surface of the transport belt 140 are always completely the same, the phases and periods of the detection signals S1 and S2 match. Thus, the matching process is performed.

  Here, in this embodiment, the feeding speed of the paper P by the gate drive roller 120 and the moving speed of the transport surface of the transport belt 140 are set to be the same, but each speed is actually small. Since both fluctuate independently, both signals may be instantaneously shifted, and the phases and periods of both signals do not always coincide completely.

  In this embodiment, when the rotational speed of the gate drive roller 120 and the moving speed of the transport surface of the transport belt 140 are completely the same, the cycle of the detection signal S2 of the rotary encoder 125 is The detection signal S1 is configured to be a natural number times the period of the detection signal S1 or a natural number. That is, when the movement amount of the conveyance belt 140 and the rotation amount of the gate driving roller 120 corresponding to the predetermined movement amount of the paper P as the material to be conveyed are counted as respective units, the arrangement cycle of the detected elements of the linear encoder 148 is calculated. The count value indicated and the count value indicating the arrangement period of the detected elements of the rotary encoder 125 have a natural number multiple or a relation of a natural number. The relationship between the arrangement periods is known in advance from the relationship between the structure of the gate roller 120 and the rotary encoder 125 and the structure of the conveyor belt 140 and the linear encoder 148. A correction signal SC having a period that matches the detection signal S1 is generated.

  4 to 6 are timing charts showing the waveforms of the signals as specific examples. Here, the timing charts of FIGS. 4 to 6 are drawn on the premise that the rotational speed of the gate driving roller 120 and the moving speed of the transport surface of the transport belt 140 are completely the same, and the following explanation will be given. The same premise is performed.

  For example, as shown in the timing chart of FIG. 4, the phase difference between the detection signal S1 of the linear encoder 148 and the detection signal S2 of the rotary encoder 125 is Ta, and the cycle T1 of S1 and the cycle T2 of S2 are the same. To do. In this case, when the detection signal S2 is input to the phase delay circuit 222, the phase of the detection signal S2 is delayed by the phase difference Ta, and the correction signal SC whose phase and period match with the detection signal S1 is obtained. In this case, the output matching circuit 220 can be configured by only the phase delay circuit 222.

  In the example shown in FIG. 5, the cycle T2 of the detection signal S2 is set to be twice the cycle T1 of the detection signal S1. In this case, first, the detection signal S2 is delayed by the phase difference Ta by the phase delay circuit 222 to generate the phase delay signal SB. This phase delay signal SB has the same phase as the detection signal S1. Next, the phase delay signal SB is doubled by the period matching circuit 224 to generate the correction signal SC. Therefore, the phase and period of the correction signal SC coincide with those of the detection signal S1. In this case, the period matching circuit 224 is a double circuit.

  In the example shown in FIG. 6, the period T2 of the detection signal S2 is set to ½ times the period T1 of the detection signal S1. In this case, first, the detection signal S2 is delayed by the phase difference T1-Ta by the phase delay circuit 222 to generate the phase delay signal SB. In this case, as a matter of course, the phase difference Ta may be delayed as described above. Next, the phase delay signal SB is divided by two by the period matching circuit 224 to generate the correction signal SC. Therefore, the correction signal SC has the same pulse train phase and cycle as that of the detection signal S1. In this case, the period matching circuit 224 is a divide-by-2 circuit.

  The description will be continued based on FIG. 3 again. Both the detection signal S1 of the linear encoder 148 and the correction signal SC output from the output conversion circuit 220 are input to the signal changeover switch 240, and the above-described separation timing signal SQ output from the main control unit 180 is added. In response, either one is switched and output. The initial state of the signal changeover switch 240 is set to output the correction signal SC, but when the separation timing signal SQ changes to a state in which the gate driving roller 120 is separated from the paper P, the output is changed to the correction signal SC. Is switched to the detection signal S1. As the signal selector switch 240, for example, a mechanical switch, a relay, an analog switch (semiconductor switch), or the like can be used.

  The timing signal generation circuit 260 is supplied with either the detection signal S1 of the linear encoder 148 or the correction signal SC of the output conversion circuit 220 by the signal switch 240, and generates a timing signal based on these signals. The circuit 260 generates a timing signal ST. This timing signal ST is a periodic signal having a period corresponding to the moving speed of the conveying surface of the conveying belt 140 indicated by the detection signal S1 or the sending speed by the gate driving roller 120 indicated by the correction signal SC.

  The head drive circuit 280 is supplied with the timing signal ST output from the timing signal generation circuit 260, and the head drive circuit 280 forms a drive signal SD for driving the print head 160 based on the timing signal ST. For example, the drive signal SD causes the print head 160 to generate an operation (ink droplet ejection operation) corresponding to a control signal or print data supplied from the main control unit 180 at a timing synchronized with the timing signal ST. It is a periodic signal having a predetermined waveform.

  Next, the operation of the present embodiment configured as described above will be described. FIG. 7 is a schematic flowchart showing an outline of the operation procedure of the present embodiment. The operation described below is executed by the operation of each unit under the control of the main control unit 180 described above. First, the paper P is fed by a paper feeding mechanism (not shown) (S1), and the motor 142 is operated based on the drive signal from the drive circuit 143, and the driving of the transport belt 140 is started (S2). Thereafter, the leading edge of the paper P is abutted against the contact portion between the gate driving roller 120 and the gate driven roller 121 by the above-described paper feeding operation, and skew correction is performed on the paper P and the leading edge of the paper P is positioned. (S3).

  Next, the absolute position of the conveyor belt 140 is measured based on the origin detection signal S0 of the origin detector 149 and the detection signal S1 of the linear encoder 148, and the timing for sending out the paper P (sending timing) is awaited (S4). This delivery timing is the timing when the gate drive roller 120 starts to feed the paper P. For example, when the paper P is supplied onto the transport surface of the transport belt 140 by a subsequent transport operation of the paper P, the paper P Is set in advance as a value indicating a predetermined absolute position of the conveyor belt 140 determined so as not to be placed on the joint of the conveyor belt 140 or the joint of the detected portion 148a of the linear encoder 148. Yes. Then, when the above delivery timing arrives, that is, when the measured absolute position reaches the above value, the motor 122 is operated by the drive signal of the drive circuit 123, and the rotational drive of the gate drive roller 120 is started (S5). As a result, the paper P is sent out toward the transport belt 140. Then, the phase difference between the detection signal S1 of the linear encoder 148 and the detection signal S2 of the rotary encoder 125 is measured (S6), and the detection signal S2 of the rotary encoder 125 is delayed by the phase difference or a phase corresponding thereto, If necessary, the correction signal SC is further multiplied or divided to generate a correction signal SC matched with the detection signal S1 (S7).

  Next, when the paper P reaches a predetermined printing start position (S8), printing on the paper P is started by the print head 160 under the control of the main control unit 180 (S9). At this time, as described above, the paper P is being sent out by the gate drive roller 120, and the signal changeover switch 240 supplies the correction signal SC to the timing signal generation circuit 260, so that based on the correction signal SC. A timing signal ST is generated, and the print head 160 is driven by a drive signal SD formed by the head drive circuit 280 in synchronization with the timing signal ST.

  Thereafter, when the predetermined range on the leading end side of the paper P is placed on the transport surface of the transport belt 140, the separation timing signal SQ is changed (S10), and the gate driving roller 120 is separated from the paper P. As a result, the paper P is moved by the conveyor belt 140. At the same time, the signal changeover switch 240 performs a signal changeover operation by the same separation timing signal SQ and supplies the detection signal S1 of the linear encoder 148 to the timing signal generation circuit 260, whereby the timing is based on the detection signal S1. A signal ST is generated, and a drive signal SD is formed to drive the print head 160 (S11).

  As described above, the printing is continued while the paper P is moved by the transport belt 140, and when the printing range is finally finished (S12), the drive of the print head 160 is stopped under the control of the main control unit 180, and the paper P A series of printing end processes such as a discharging operation and driving stop of the conveying belt 140 are executed (S13).

  In this embodiment, before printing is performed based on the detection signal S1 of the linear encoder 148 as in the prior art, the correction formed from the detection signal S2 of the rotary encoder 125 in the process of feeding the paper P by the gate drive roller 120. Printing can be performed based on the signal SC. That is, printing is started without sacrificing the print quality in the process of feeding the paper P, and thereafter, in the process of transporting the paper P by the transport belt 140, the correction signal SC is switched to the detection signal S1 by the signal changeover switch 240 and printing is performed. Can continue. Accordingly, the distance between the gate driving roller 120 and the print head 160 can be reduced without sacrificing the printing range for the paper P and the adsorption performance of the paper P. For example, the conveyance distance of the conveyance belt 140 can be reduced. Thus, it is possible to reduce the size of the transport device and the printing device.

  Further, since the phase and period of the correction signal SC formed from the detection signal S2 of the rotary encoder 125 is consistent with the detection signal S1 of the linear encoder 148, the paper P by the transport belt 140 is fed from the process of feeding the paper P by the gate drive roller 120. Since the discontinuity of printing hardly occurs at the time of shifting to the P transport process, the generation of white lines and dark lines can be suppressed, so that the print quality can be ensured also in this respect.

  In the present embodiment, the rotation amount (feed amount) of the gate drive roller 120 configured so as not to be deformed in the radial direction is detected by the rotary encoder 125, so that the roller of the gate drive roller 120 when the paper P is fed. Since the diameter does not change, the correspondence between the rotation amount of the gate driving roller 120 and the feeding amount of the paper P does not change, and the gate driven roller 121 and the gate driven roller are elastically deformed at the time of feeding. Since the contact area of the roller 121 with respect to the paper P is increased, it is possible to prevent a deviation when the paper P is delivered. Therefore, the amount of paper P delivered when the paper P is fed by the gate drive roller 120 can be detected with high accuracy by the detection signal S2 or the correction signal SC.

  The conveying device and the printing apparatus of the present invention are not limited to the illustrated examples described above, and various changes can be made without departing from the scope of the present invention. For example, the print head 160 of the present embodiment is fixed in a state where the conveyance belt 140 is stretched over the conveyance direction F, but the print head 160 is substantially orthogonal to the conveyance direction F of the conveyance belt 140. It may be configured to reciprocate in the direction.

  In the delivery mechanism of the present embodiment, the gate drive roller 120 is configured not to be deformed in the radial direction and the gate driven roller 121 is configured to be elastically deformable in the radial direction. The gate drive roller 120 may be configured to be elastically deformable in the radial direction, and the gate driven roller 121 may be configured not to be deformed in the radial direction. In this case, in order to detect the accurate delivery amount of the paper P, it is desirable to detect not the rotation amount of the gate drive roller 120 but the rotation amount of the gate driven roller 121.

  Further, in the present embodiment, the rotary encoder 125 is attached to the gate drive roller 120 to detect the rotation amount. However, from the drive signal of the drive circuit 123 that controls the motor 122 that drives the gate drive roller 120 to rotate. The rotation amount of the gate drive roller 120 may be detected. This is particularly effective when the motor 122 is a stepping motor. Further, when an encoder is incorporated in the motor 122, this encoder signal may be extracted as a detection signal.

  In this embodiment, the detection signal S2 of the rotary encoder 125 is matched with the detection signal S1 of the linear encoder 148 by the output conversion circuit 220. Conversely, the detection signal S1 of the linear encoder 148 is output to the output conversion circuit. May be configured to match the detection signal S2 of the rotary encoder 125.

1 is a schematic plan view schematically showing a printing apparatus according to an embodiment of the present invention. Schematic longitudinal sectional view (a) schematically showing a state in which the leading edge of the paper is abutted between the gate driving roller and the gate driven roller in the embodiment, and a state in which the paper is fed out by the gate driving roller and the gate driven roller FIG. 2 is a schematic longitudinal sectional view (b). FIG. 2 is a schematic block diagram showing a configuration of a head drive circuit in the embodiment. 5 is a timing chart showing a detection signal S1, a detection signal S2, and a correction signal SC in the embodiment. The timing chart which shows another detection signal S1, detection signal S2, phase delay signal SB, and correction signal SC. 9 is a timing chart showing still another detection signal S1, detection signal S2, phase delay signal SB, and correction signal SC. 3 is a schematic flowchart illustrating a driving procedure of the printing apparatus according to the present embodiment. The schematic plan view which showed the conventional printing apparatus typically. The schematic longitudinal cross-sectional view which shows typically the cross section cut | disconnected along the AA line of FIG. FIG. 6 is a schematic configuration diagram schematically illustrating a configuration of a print control system in a conventional printing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Printing apparatus, 120 ... Gate drive roller, 121 ... Gate driven roller, 122, 142 ... Motor, 123, 143 ... Motor drive circuit, 125 ... Rotary encoder, 140 ... Conveyor belt, 148 ... Linear encoder, 140b ... Origin, 144: driving roller, 145: driven roller, 146: tension roller, 149 ... origin detector, 160 ... print head, 162 ... control unit, 180 ... main control unit, 220 ... output conversion circuit, 222 ... phase delay circuit, 224 ... period matching circuit, 240 ... signal changeover switch, 260 ... timing signal generation circuit, 280 ... drive signal generation circuit, P ... paper, S1, S2 ... detection signal, SB ... phase delay signal, SC ... correction signal, Ta ... position Phase difference

Claims (4)

A transport unit configured so that a transport surface of a transport belt used for transporting a transported material is movable;
A delivery section for delivering the material to be conveyed onto the conveying surface of the conveying belt;
A first detector for detecting a movement amount of a conveyance surface of the conveyance belt;
A second detector for detecting a delivery amount of the transported material by the delivery unit;
A signal switching unit that outputs a detection signal of the first detector when the transported material moves by the transport unit, and outputs a detection signal of the second detector when the transported material moves by the sending unit. When,
A separation / contact part for separating the delivery part from / to the transported material ;
An output matching unit for matching the detection signal of the first detector and the detection signal of the second detector ;
The signal switching unit switches the detection signal of the second detector to the detection signal of the first detector in synchronization with the separation timing of the delivery unit with respect to the conveyed material by the separation / contact portion. Conveying device. The output matching unit includes an output conversion circuit that converts one of the detection signal of the first detector and the detection signal of the second detector so as to match the other, and the detection of the first detector The conveyance device according to claim 1 , wherein the phase of the signal and the detection signal of the second detector are matched. A transport unit configured so that a transport surface of a transport belt used for transporting a transported material is movable;
A delivery section for delivering the material to be conveyed onto the conveying surface of the conveying belt;
A printing section for printing on the material to be conveyed;
A first detector for detecting a movement amount of a conveyance surface of the conveyance belt;
A second detector for detecting a delivery amount of the transported material by the delivery unit;
A signal switching unit that outputs a detection signal of the first detector when the transported material moves by the transport unit, and outputs a detection signal of the second detector when the transported material moves by the sending unit. When,
A print control unit that controls the printing unit based on an output of the signal switching unit;
A separation / contact part for separating the delivery part from / to the transported material ;
An output matching unit for matching the detection signal of the first detector and the detection signal of the second detector ;
The signal switching unit switches the detection signal of the second detector to the detection signal of the first detector in synchronization with the separation timing of the delivery unit with respect to the conveyed material by the separation / contact portion. Printing equipment. The output matching unit includes an output conversion circuit that converts one of the detection signal of the first detector and the detection signal of the second detector so as to match the other, and the detection of the first detector The printing apparatus according to claim 3 , wherein the phase of the signal and the detection signal of the second detector are matched.

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