JP2010208732A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase productivity in printing, by properly correcting a skew of printing paper. <P>SOLUTION: This printer has a primary paper feeding part 12 for taking out and carrying one by one of the printing paper W placed on a paper feeding tray, a secondary paper feeding part 14 for carrying the printing paper W carried by the primary paper feeding part 12 to a printing part 30 in the predetermined timing, a sound sensor 17 arranged in the vicinity of a carrying passage of the printing paper W between the primary paper feeding part 12 and the secondary paper feeding part 14 and detecting a butting sound generated when the printing paper W carried by the primary paper feeding part 12 butts against the secondary paper feeding part 14, and a control part 80 for controlling the primary paper feeding part 12 based on the butting sound detected by the sound sensor 17. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printing apparatus that reduces a noise level and prints quickly.

  In a general printing apparatus, print sheets stacked on a paper feed tray are taken out one by one by a primary paper feed roller, and the taken print paper is placed on the downstream side of the primary paper feed roller. The paper is fed to the printing unit by the secondary paper feed roller at a predetermined timing and printed by the printing unit. Here, in a general printing apparatus, when the printing paper reaches the secondary paper feeding roller, the printing paper is abutted against the secondary paper feeding roller, and the printing paper is loosened to feed the printing paper to the printing unit. Skew correction and paper feed timing synchronization.

  In such a printing apparatus, the feed amount of the primary paper feed roller does not necessarily match the transport amount of the print paper due to the secular change of the primary paper feed roller and the occurrence of slippage between the primary paper feed roller and the paper.

  For this reason, the printing paper is secondarily fed from the time when it is detected that the printing paper has passed by the optical detector disposed on the conveyance path of the printing paper from the primary paper feeding roller to the secondary paper feeding roller. It was difficult to accurately calculate the time until reaching the mechanism.

  As a result, the amount of slack of the printing paper when it reaches the secondary paper feed roller needs to be larger than necessary in design, and the larger this amount of slack, the more the secondary paper feed roller is driven, There is a problem that the slack release sound when the slack is released increases, and the larger the amount of slack, the longer the time loss for forming the slack amount, and the lower the productivity of printing.

  Patent Document 1 discloses a control device for an image forming apparatus that determines whether or not an image defect (image defect) exists using sound information detected by a sensor installed in the vicinity of a path along which a sheet is conveyed. Has been proposed.

JP 2005-205679 A

However, in the control device described in Patent Document 1, since it is determined whether or not there is an image defect using sound information, the amount of slack must be increased in order to appropriately correct skew feeding. As a result, there is a problem that the noise is loud and the printing speed is slow.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a printing apparatus that appropriately performs skew correction of printing paper and enables low-noise and high-speed printing.

  In order to achieve the above object, the first feature of the printing apparatus according to the present invention is that a first paper feeding means for taking out and transporting one sheet of printing paper placed on a paper feeding table, and the first paper supply. A second paper feeding unit that transports the printing paper conveyed by the paper unit to the printing unit at a predetermined time; and the conveyance of the printing paper between the first paper feeding unit and the second paper feeding unit. A detecting unit that is provided near the path and detects a wave generated when the printing paper conveyed by the first sheet feeding unit hits the second sheet feeding unit; and the wave detected by the detecting unit And a control means for controlling the first paper feed means.

  In order to achieve the above object, a second feature of the printing apparatus according to the present invention is that the first paper feed means includes a primary paper feed roller in the vicinity of the paper feed table, and the primary paper feed roller By rotating, the printing paper placed on the paper feed table is picked up and conveyed one by one, and the control means transfers the printing paper conveyed by the first paper feeding means to the second paper feeding means. A slack amount setting means for setting a slack amount setting value formed by hitting the slack as a slack amount setting value, a wave detected by the detecting means, and a slack amount setting value set by the slack amount setting means. And a rotation amount adjusting means for adjusting the rotation amount of the primary paper feed roller.

  In order to achieve the above object, a third feature of the printing apparatus according to the present invention is that a primary paper feed roller is provided in the vicinity of the paper feed table, and the primary paper feed roller is rotated to rotate the primary paper feed roller. A first paper feeding means for taking out and transporting the placed printing paper one by one; and a secondary paper feeding roller on the transport path of the printing paper, and by rotating the secondary paper feeding roller, A second paper feeding means for conveying the printing paper conveyed by the first paper feeding means to the printing means one by one at a predetermined time; the first paper feeding means; and the second paper feeding means; And a detecting means for detecting a wave generated when the slack of the printing paper is released, and generated when the slack detected by the detecting means is released. On the basis of the wave to be rotated and the rotation amount of the secondary paper feed roller. A slack amount calculating means for calculating a slack amount formed by striking the second paper feeding means, and a slack amount calculated by the slack amount calculating means so as to approach a preset slack amount setting value. And a rotation amount adjusting means for adjusting the rotation amount of the primary paper feed roller.

  In order to achieve the above object, a fourth feature of the printing apparatus according to the present invention is that the detecting unit is configured such that the detection unit vibrates when the printing sheet hits the second sheet feeding unit, and the printing sheet is slack. Vibration detecting means for detecting at least one of vibrations generated when the printing is released, sound generated when the printing paper hits the second paper feeding means, and looseness of the printing paper are released At least one of sound detection means for detecting at least one of the sounds generated when the sound is generated.

  In order to achieve the above object, a fifth feature of the printing apparatus according to the present invention is that a primary paper feed roller is provided near the paper feed table, and the primary paper feed roller is rotated to rotate the primary paper feed roller. A first paper feeding means for taking out and transporting the placed printing paper one by one; and a secondary paper feeding roller on the transport path of the printing paper, and by rotating the secondary paper feeding roller, A second paper feeding means for conveying the printing paper conveyed by the first paper feeding means to the printing means one by one at a predetermined time; the first paper feeding means; and the second paper feeding means; Between the printing paper transport path and the abutting sound generated when the printing paper transported by the first paper feeding means hits the second paper feeding means, and the looseness of the printing paper Sound detecting means for detecting a loosening release sound when the sound is released; Vibration detecting means provided in the vicinity of the transport path of the printing paper between the paper means and the second paper feeding means, and detecting vibration generated when the slack of the printing paper is released; and the first A slack amount setting means for setting, as a slack amount setting value, a slack amount setting value formed when the printing paper conveyed by the paper feeding means hits the second paper feeding means, and detected by the sound detection means The slack formed by the printing paper hitting the second paper feeding means based on the loosening release sound, the vibration detected by the vibration detecting means, and the rotation speed of the secondary paper feeding roller. The amount of slack calculation means for calculating the amount, and the amount of slack calculated by the amount of slack calculation means calculated in the past by the amount of slack calculation means so that the slack amount setting value set by the amount of slack setting means approaches. Slack Based on the sound strikes detected by the sound detection means and the slack set value, and a rotation amount adjusting means for adjusting the amount of rotation of the primary paper feeding roller.

  According to the printing apparatus according to the present invention, it is possible to appropriately perform skew correction of printing paper and increase printing productivity.

1 is an overall configuration diagram illustrating an overall configuration of a printing apparatus according to an embodiment of the present invention. FIG. 2 is a configuration diagram illustrating a configuration in the vicinity of a side paper feeding unit of a printing apparatus according to an embodiment of the present invention. FIG. 2 is a functional configuration diagram illustrating a functional configuration of a printing apparatus according to an embodiment of the present invention. 5 is a flowchart illustrating a processing flow of the printing apparatus according to the embodiment of the present invention. 6 is a time chart showing a rotation speed of a primary paper feed roller, a rotation speed of a secondary paper feed roller, and a detection value by a sound sensor in a printing apparatus according to an embodiment of the present invention. It is a figure explaining rotation speed adjustment of the primary paper feed roller by the rotation speed adjustment part of the control part with which the printing apparatus which is one embodiment of the present invention is provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Overall configuration of printing apparatus>
FIG. 1 is an overall configuration diagram showing an overall configuration of a printing apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the printing apparatus 1 includes a side paper feed unit 10, an internal paper feed unit 20, a printing unit 30, a paper discharge unit 40, and a reversing unit 50.

  The side paper feeding unit 10 includes a paper feeding table 11 on which the printing paper W is stacked, and a primary paper feeding unit 12 that conveys only the uppermost printing paper W from the paper feeding table 11 onto the paper feeding system conveyance path FR. And a secondary paper feeding unit 14 that carries the printing paper W conveyed by the primary paper feeding unit 12 to the printing unit 30. The printing paper W transported on the paper feed system transport path FR by the primary paper feed unit 12 comes into contact with the secondary paper feed unit 14 and is slackened. Then, due to this slackness, the leading edge of the printing paper W is aligned and skew correction is performed, and is conveyed on the circulation system conveyance path CR toward the printing unit 30 at a predetermined timing.

  The internal paper feeding unit 20 includes a paper feeding table 21a on which the printing paper W is stacked, and a primary paper feeding unit 22a that conveys only the uppermost printing paper W from the paper feeding table 21a onto the paper feeding system conveyance path FR. A sheet feeding table 21b on which the printing sheets W are stacked, a primary sheet feeding unit 22b that conveys only the uppermost printing sheet W from the sheet feeding table 21b onto the sheet feeding system conveyance path FR, and the printing sheet W. Are stacked, a primary paper feed unit 22c that transports only the uppermost print paper W from the paper feed base 21c onto the paper feed transport path FR, and a paper feed on which the print paper W is stacked. A paper base 21d and a primary paper feed unit 22d that transports only the uppermost printing paper W from the paper feed base 21d onto the paper feed system transport path FR are provided.

  The printing paper W transported onto the paper feed system transport path FR by the primary paper feed units 22a, 22b, 22c, and 22d respectively includes a plurality of transport rollers such as transport rollers 23 installed on the paper feed system transport path FR. As a result, the sheet is conveyed on the sheet feeding system conveyance path FR and hits the secondary sheet feeding unit 14. As a result, the printing paper W is slackened, and by this slackness, the leading edge of the printing paper W is aligned and skew correction is performed, and the printing paper W is conveyed toward the printing unit 30 on the circulation system conveyance path CR at a predetermined timing.

  The printing unit 30 includes a head unit 31 in which a plurality of print heads are incorporated, and an annular conveyance belt 32 provided on the opposing surface of the head unit 31, and is fed by the secondary paper feeding unit 14. The printing paper W is adsorbed on the conveyance belt 32 by a suction unit (not shown) installed in the annular conveyance belt 32, and is conveyed in units of lines by ink ejected from the head unit 31 while being conveyed at a speed determined by printing conditions. Is printed on the printing paper W.

  The printing paper W printed by the printing unit 30 is conveyed on the circulation system conveyance path CR in the housing by a conveyance roller or the like disposed on the circulation system conveyance path CR. A switching mechanism 43 that switches whether the printing paper W conveyed on the circulation system conveyance path CR is guided to the paper discharge unit 40 or recirculated on the circulation system conveyance path CR is provided on the circulation system conveyance path CR. Is provided.

  The switching mechanism 43 guides the printing paper W to the paper discharge unit 40 when a single-sided printing mode, which is a printing mode for printing only one side of the printing paper W, is selected based on a user operation.

  The paper discharge unit 40 includes a tray-shaped paper discharge table 41 protruding from the casing of the printing apparatus 1 and a pair of paper discharge rollers 42 that guide the print paper W to the paper discharge table 41. Then, the printing paper W printed by the printing unit 30 is transported to the paper discharge tray 41 by the paper discharge roller 42 and stacked on the paper discharge tray 41 with the printing surface facing down.

  In addition, when the duplex printing mode, which is a printing mode for printing both sides of the printing paper W, is selected, the front side of the printing paper W (the first printed side is “front side”, and the next printed side is “back side” At the end of printing, the switching mechanism 43 guides the printing paper W to the reversing unit 50 without guiding it to the paper discharge unit 40.

  The reversing unit 50 conveys the printing paper W from the reversing table 51 to the reversing table 51, or conveys the printing paper W from the reversing table 51 onto the circulation conveying route CR. The reversing roller 52 is provided.

  The printing paper W guided to the reversing unit 50 by the switching mechanism 43 is conveyed by the reversing roller 52 from the circulation system conveyance path CR to the reversing table 51, and after a predetermined time has elapsed, is conveyed from the reversing table 51 to the circulation system conveyance path CR. By doing so, the front and back are reversed with respect to the circulation system conveyance path CR. Then, the printing paper W whose front and back sides are reversed is conveyed on the circulation system conveyance path CR by a plurality of rollers such as a conveyance roller 53 provided on the circulation system conveyance path CR, and abuts against the secondary paper feeding unit 14. As a result, the printing paper W is slackened, and by this slackness, the leading edge of the printing paper W is aligned and skew correction is performed, and the printing paper W is conveyed toward the printing unit 30 on the circulation system conveyance path CR at a predetermined timing.

<Configuration of Side Paper Feed Unit 10>
FIG. 2 is a configuration diagram showing a configuration in the vicinity of the side paper feeding unit 10 of the printing apparatus 1 according to the embodiment of the present invention.

  As shown in FIG. 2, the printing paper W is conveyed to the secondary paper feeding unit 14 from three paths of the side paper feeding unit 10, the internal paper feeding unit 20, and the reversing unit 50.

  Specifically, the printing paper W transported from the side paper feed unit 10 by the primary paper feed unit 12 on the paper feed path FR, the primary paper feed units 22a, 22b, 22c, The printing paper W or the reversing unit 50 conveyed by the conveyance rollers 23a, 23b on the sheet feeding system conveyance path FR from the sheet feeding tables 21a, 21b, 21c, 21d by the sheet 22d. The reversing roller 52 conveys the printing paper W conveyed on the circulation system conveyance path CR, and conveyed on the circulation system conveyance path CR by the conveyance rollers 53a and 53b, on the circulation system conveyance path CR. It is conveyed to the paper unit 14.

  Therefore, a junction point where the transport path of the fed printing paper W and the path through which the back-side printing paper is circulated is joined is present in front of the secondary paper feed unit 14 in the transport direction. . On the basis of this merging point, the path on the paper feed mechanism side is referred to as a paper feed system transport path FR, and the other path is referred to as a circulation system transport path CR.

  The primary paper feed unit 12 includes primary paper feed rollers 12a and 12b, a separating plate 12d, and a primary paper feed drive mechanism 12c. The primary paper feed drive mechanism 12c is a control unit 80 described later. The uppermost printing paper W stacked on the paper feed tray 11 is transported onto the paper feed system transport path FR by rotating the primary paper feed rollers 12a and 12b based on the control signal from. Specifically, the primary paper feed roller 12a made of an elastic material such as rubber is pressed against the uppermost print paper W stacked on the paper feed tray 11 with a predetermined pressure, and the print paper W The surface of the water is caused to flow downstream by the friction force. Similarly, the primary paper feed roller 12b made of an elastic material such as rubber sandwiches the printing paper W between the surface of the printing paper W and the separating plate 12d, and feeds only one sheet to the paper feeding system transport path FR. Carry up. At this time, due to the secular change of the primary roller and the slippage between the primary roller and the printing paper, the feed amount of the primary roller and the transport amount of the printing paper do not necessarily match. Further, the slip rate varies depending on the type of printing paper W, the setting state of the separating plate 12d, the degree of deterioration of the primary paper feeding rollers 12a and 12b, and the like.

  The secondary paper feed unit 14 includes secondary paper feed rollers 14a and 14b and a secondary paper feed drive mechanism 14c. The secondary paper feed drive mechanism 14c receives a control signal from a control unit 80 described later. Based on this, the secondary paper feed rollers 14a and 14b are rotated. Specifically, unlike the primary paper feed rollers 12a and 12b, the amount of movement of the print paper W can be reduced by sandwiching the print paper W conveyed by the secondary paper feed rollers 14a and 14b and rotating it intermittently. Control accurately. That is, the feed amount of the secondary paper feed rollers 14a and 14b is substantially equal to the transport amount of the printing paper W.

  Further, in the printing apparatus 1 according to the embodiment of the present invention, between the primary paper feeding unit 12 and the secondary paper feeding unit 14, in the vicinity of the circulation system conveyance path CR that is the conveyance path of the printing paper W. A resist sensor 15, a sound sensor 17, and a vibration sensor 18 are provided.

  The registration sensor 15 is a light transmission type or reflection type sensor, and detects the leading edge and the trailing edge of the printing paper W conveyed on the circulation conveyance path CR.

  The sound sensor 17 is generated when the printing paper W transported on the circulation transport path CR hits the secondary paper feed unit 14 and the printing paper W hits the secondary paper feed unit 14. The slack release sound when the slack is released is detected.

  The vibration sensor 18 detects vibration that occurs when the slack caused by the printing paper W hitting the secondary paper supply unit 14 is released.

<Functional configuration of printing device>
FIG. 3 is a functional configuration diagram illustrating a functional configuration of the printing apparatus 1 according to the embodiment of the present invention.

  As shown in FIG. 3, the printing apparatus 1 includes a side paper feed unit 10, an internal paper feed unit 20, a printing unit 30, a paper discharge unit 40, a reversing unit 50, a transport unit 60, a RAM 71, and a ROM 72. And an operation unit 73 and a control unit 80.

  Among these configurations, the side paper feed unit 10, the internal paper feed unit 20, the printing unit 30, the paper discharge unit 40, and the reversing unit 50 have been described above, and thus description thereof will be omitted.

  The transport unit 60 has a plurality of transport rollers and the like arranged on the paper feed transport path FR and the circulation transport path CR, and rotates a plurality of transport rollers at a predetermined timing, thereby printing paper. W is transported on the paper feed system transport path FR or on the circulation system transport path CR. Further, the transport unit 60 has a switching mechanism 43 disposed on the circulation system transport path CR, and the switching mechanism 43 transfers the printing paper W transported on the circulation system transport path CR to the paper discharge unit 40. Switching between guiding or recirculating on the circulation system conveyance path CR is switched.

  The RAM 71 is composed of a volatile semiconductor or the like, and stores data and the like necessary for the control unit 80 to execute various processes. The RAM 71 stores a measured value of the slack amount at the end of printing of each page. At this time, it is preferable that the stored slack amount is stored in pairs with each paper type.

  The ROM 72 is composed of a nonvolatile semiconductor or the like, and stores various control programs executed by the control unit 80, a slack amount initial value, and the like. The slack amount initial value is more preferably stored as an appropriate value for each paper type.

  The operation unit 73 includes an operation key, a display / input panel, and the like, and an operation signal for setting double-sided / single-sided printing when the user presses the operation key or touches the display / input panel. Then, an operation signal for setting the print size or an operation signal for requesting the start of printing is generated, and the generated operation signal is supplied to the control unit 80.

  The control unit 80 performs central control of the printing apparatus 1. Moreover, the control part 80 is provided with the slack amount setting part 80a, the slack amount calculation part 80b, and the rotation amount adjustment part 80c on the function.

  The slack amount setting unit 80a reads the setting value of the slack amount formed when the printing paper W hits the secondary paper feeding unit 14 from the ROM 72 as a slack amount setting value and sets it.

  The slack amount calculation unit 80b starts from the time when the operation of the secondary paper feed rollers 12a and 12b is started until the time when the slack release sound detected by the sound sensor 17 and the vibration detected by the vibration sensor 18 are detected. The actual amount of slack formed on the printing paper W by the rotation of the secondary paper feed rollers 14a and 14b is calculated.

  When the user's operation selects a paper type or size of the printing paper W stacked on the primary paper feeding unit 12 such as the paper type or size, the rotation amount adjustment unit 80c is a slack amount setting unit. Based on the initial value of the sag amount set by 80a, the sag amount calculated by the sag amount calculation unit 80b, or the latest sag amount read from the RAM 71 is set by the sag amount setting unit 80a. The feed amounts (rotational speed, rotational acceleration, operating time) of the primary paper feed rollers 12a and 12b of the primary paper feed unit 12 are adjusted so as to approach the slack amount initial value.

  Similarly, when a user operation is selected to affect the conveyance such as the paper type of the printing paper W stacked in one of the primary paper feeding units 22a, 22b, 22c, and 22d, the rotation is performed. The amount adjusting unit 80c is configured so that the slack amount calculated by the slack amount calculating unit 80b or the latest slack amount read from the RAM 71 approaches the slack amount initial value set by the slack amount setting unit 80a. The feed amount (rotational speed, rotational acceleration, operation time) of the selected primary paper feed roller of the primary paper feed units 22a, 22b, 22c, and 22d is adjusted.

  Even when double-sided printing is selected by the user's operation, the rotation amount adjusting unit 80c, after finishing the front surface printing of the printing paper W, uses the reversing roller 52 of the reversing unit 50 in the same manner as described above. Adjust the feed amount (rotational speed, rotational acceleration, operation time).

<Operation of Printing Apparatus 1>
Next, the operation of the printing apparatus 1 according to an embodiment of the present invention will be described.

  FIG. 4 is a flowchart showing a processing flow of the printing apparatus 1 according to the embodiment of the present invention. FIG. 5 is a flowchart of the primary paper feed rollers 12a and 12b in the printing apparatus 1 according to the embodiment of the present invention. 6 is a time chart showing the rotation speed, the rotation speed of the secondary paper feed rollers 14a and 14b, and the value detected by the sound sensor 17. Here, as an example, a case where single-sided printing is performed using the printing paper W stacked on the paper feed tray 11 will be described.

  As shown in FIG. 4, when an operation for requesting the start of printing is performed after the user has performed operations for paper setting, number of copies setting, and single-sided / double-sided printing setting, the operation unit 73 includes setting contents. An operation signal for requesting the start of printing is supplied to the control unit 80 (step S101).

  In step S101, when an operation signal for requesting the start of printing is supplied (in the case of YES), the control unit 80 indicates that the uppermost portion of the printing paper W loaded on the paper feed tray 11 of the side paper feed unit 10 is the side. After the sheet feeding unit 10 is raised to a position where it presses against the primary sheet feeding unit 12, the initial slack amount value is read from the ROM 71, and the initial slack amount value is set in the slack amount setting unit 80a (step S103).

Next, the control unit 80 performs various printing preparation settings such as the conveyance speed setting of the conveyance belt 32 of the printing unit 30 and substitutes the value of the number of prints into the print set number C based on the supplied operation signal. Then, the value of counter i is initialized (step S105).
In the flowchart shown in FIG. 4, the following steps S <b> 107 to S <b> 139 are executed as one cycle for each printing sheet W. Thereby, as shown in the timing chart of FIG. 5, the process from the time T1 to the time T10 is repeatedly executed as one cycle.
Next, the control unit 80 starts rotation of the primary paper feed rollers 12a and 12b of the primary paper feed unit 12 at time T1 (step S107). Specifically, the primary paper feed drive mechanism 12 c of the primary paper feed unit 12 starts rotating the primary paper feed rollers 12 a and 12 b based on the control signal supplied from the control unit 80.

  When the rotation speed of the primary paper feed rollers 12a and 12b reaches a predetermined rotation setting speed V1 at time T2 (step S109), the control unit 80 sets the primary paper feed rollers 12a and 12b. The primary sheet feeder 12 is controlled so as to maintain the rotation speed V at the rotation setting speed V1 (step S111). Specifically, the primary paper feed drive mechanism 12c of the primary paper feed unit 12 rotates the primary paper feed rollers 12a and 12b at the rotation set speed V1 based on the control signal supplied from the control unit 80. .

  In step S107, the rotation of the primary paper feed rollers 12a and 12b is started, whereby the printing paper W is transported from the paper feed tray 11 on the paper feed system transport path FR and further transported on the circulation system transport path CR. Is done. At time T3, when the leading edge of the conveyed printing paper W is detected by the registration sensor 15 (step S113), the control unit 80 decelerates the rotational speed V of the primary paper feed rollers 12a and 12b.

  Then, when the rotational speed V of the primary paper feed rollers 12a and 12b reaches the rotation set speed V2 at time T4, the control unit 80 controls the primary paper feed unit 12 so as to hold at the rotation set speed V2. (Step S115). Specifically, the primary paper feed drive mechanism 12c of the primary paper feed unit 12 rotates the primary paper feed rollers 12a and 12b at the rotation set speed V2 based on the control signal supplied from the control unit 80. .

  Next, in the rotation amount adjustment unit 80c of the control unit 80, the sound sensor 17 detects the abutment sound that is generated when the printing paper W conveyed on the circulation conveyance path CR hits the secondary paper feeding unit 14. It is determined whether or not (step S117). Specifically, the rotation amount adjustment unit 80c detects that the sound sensor 17 has hit when the sound sensor 17 detects a sound of a predetermined volume or more within a predetermined time after the registration sensor 15 detects the leading edge of the printing paper W. It is determined that sound has been detected. In order to detect this contact, the vibration sensor 18 may be used instead of the sound sensor 17.

  At time T5, when the rotation amount adjustment unit 80c determines that the sound sensor 17 has detected a struck sound, the control unit 80 determines whether the value of the counter i exceeds “1” or the RAM 71 It is determined whether or not the latest amount of slack is stored (step S119).

  If it is determined in step S119 whether or not the value of the counter i exceeds “1” or the most recent slack amount is stored in the RAM 71 (in the case of YES), the control unit 80 The slack amount is read, and it is determined whether or not the difference between the read slack amount and the initial slack amount value stored in the ROM 72 exceeds a preset threshold value R (step S121).

  When it is determined in step S119 that the value of the counter i is “1” or less and the most recent slack amount is not stored in the RAM 71 (in the case of NO), or in step S121, the slack amount and the slack amount When it is determined that the difference from the initial value is equal to or less than a preset threshold value R (in the case of NO), the rotation amount adjustment unit 80c of the control unit 80 causes the slack amount initial value set by the slack amount setting unit 80a. Based on the above, the rotation amount of the primary paper feed rollers 12a and 12b is adjusted (step S129). More specifically, at least one of the rotational speed, rotational acceleration, and operation time of the primary paper feed rollers 12a and 12b is adjusted.

  FIG. 6 is a diagram for explaining the rotation amount adjustment of the primary paper feed rollers 12 a and 12 b by the rotation amount adjustment unit 80 c of the control unit 80.

  As shown in FIG. 6, at time T5, the sound sensor 17 detects an abutting sound that is generated when the printing paper W strikes the secondary paper feeding unit 14, so that the rotation amount adjusting unit 80 c of the control unit 80 is detected. Is necessary for skew correction by adjusting at least one or more of the rotational speed, rotational acceleration, and operation time of the primary paper feed rollers 12a and 12b from the point of contact to operate the primary paper feed rollers 12a and 12b. After securing the minimum amount of slack, the primary paper feed rollers 12a and 12b are controlled to be stopped.

  Specifically, the area S1 indicated by the diagonal lines in FIG. 6 indicates the amount of rotation of the primary paper feed rollers 12a and 12b that generate slack when the print paper W hits the secondary paper feed unit 14, and thus the control is performed. The rotation amount adjustment unit 80c of the unit 80 stops the rotation of the primary paper feed rollers 12a and 12b so that the area S1 becomes the slack amount setting value S that is the minimum slack amount necessary for skew correction. The time T6 at which the deceleration is started is determined, and the deceleration is started to stop the rotation of the primary paper feed rollers 12a and 12b at the determined time T6.

  Here, the printing paper feed amount of the roller varies depending on the type of the printing paper W, the setting state of the separating plate 12d, the degree of deterioration of the primary paper feeding rollers 12a and 12b, and the like. Therefore, the setting state of the separating plate 12d and the usage period of the primary paper feeding rollers 12a and 12b may be stored in the RAM 71.

  On the other hand, in step S121, when it is determined in step S121 that the difference between the slack amount and the slack amount initial value exceeds a preset threshold value R (in the case of YES), the rotation amount adjustment unit of the control unit 80 80c is a slack calculated by the slack amount calculating unit 80b in the previous cycle so that a slack amount calculated by a slack amount calculating unit 80b described later approaches a slack amount setting value set by the slack amount setting unit 80a. The rotation amount of the primary paper feed rollers 12a and 12b is adjusted based on the amount, that is, the latest slack amount stored in the RAM 71 and the slack setting value (step S127).

  As described above, the rotation amount of the primary paper feed rollers 12a and 12b does not necessarily match the conveyance amount of the print paper W, and the rotation amount of the secondary paper feed rollers 14a and 14b is equal to the conveyance amount of the print paper W. Almost matches.

  Therefore, for example, the rotation amount adjustment unit 80c of the control unit 80 performs PID control or the like so that the slack amount calculated by the slack amount calculation unit 80b approaches the slack amount setting value set by the slack amount setting unit 80a. The amount of rotation of the primary paper feed rollers 12a and 12b is adjusted by feedback control. That is, the area S1 is adjusted so that the area S2 shown in FIG. 6 approaches the slack amount setting value. Specifically, the rotation amount adjustment unit 80c of the control unit 80 stops the rotation of the area S1, that is, the primary paper feed rollers 12a and 12b so that the area S2 illustrated in FIG. 6 approaches the slack amount setting value. Therefore, a time point T6 at which the deceleration is started is determined, and at the determined time point T6, the deceleration for stopping the rotation of the primary paper feed rollers 12a and 12b is started.

  As a result, the actual slack amount calculated in the previous cycle can be reflected in the slack amount setting value, so that the rotation amounts of the primary paper feed rollers 12a and 12b can be adjusted more appropriately.

  The control unit 80 starts rotating the secondary paper feed rollers 14a and 14b of the secondary paper feed unit 14 at time T7 after a predetermined time has elapsed since the primary paper feed rollers 12a and 12b stopped. (Step S131). Specifically, the secondary paper feed drive mechanism 14 c of the secondary paper feed unit 14 starts rotating the secondary paper feed rollers 14 a and 14 b based on the control signal supplied from the control unit 80.

  Next, the slack amount calculation unit 80b of the control unit 80 determines whether a slack release sound is detected by the sound sensor 17 and vibration is detected by the vibration sensor 18 (step S133). Specifically, the slack amount calculation unit 80b detects a slack release sound when the sound sensor 17 detects a sound of a predetermined volume or higher within a predetermined time after the rotation of the secondary paper feed rollers 14a and 14b is started. Is determined. Further, if the vibration sensor 18 detects a vibration greater than or equal to a predetermined vibration within a predetermined time after the rotation of the secondary paper feed rollers 14a and 14b is started, it is determined that the slack has been released.

  Next, when it is determined in step S133 that the release sound and vibration are detected, the slack amount calculation unit 80b starts the rotation of the secondary paper feed rollers 14a and 14b, the sound sensor 17 and the vibration sensor. The amount of slack formed on the printing paper W up to the point when it is determined that the slack has been released by detecting 18 is calculated, and the control unit 80 stores the calculated amount of slack in the RAM 71 (step S135). Specifically, as shown in FIG. 6, the slack amount calculation unit 80b detects a slack release sound from the time T7 when the rotation of the secondary paper feed rollers 14a and 14b starts, and detects vibration. The slanted area S2 up to the time T8 when the vibration is detected by the sensor 18 is calculated as a slack amount. When storing the amount of slack, it is more preferable to store the amount of slack according to each type of printing paper.

  Then, after incrementing the value of the counter i (step S137), the control unit 80 determines whether or not the value of the counter i has exceeded the print setting number C (step S139).

  If it is determined in step S139 that the value of the counter i has exceeded the set number of prints C (in the case of YES), the process is terminated, and if it is determined that the value of the counter i is equal to or less than the set number of prints C (NO) ), The process proceeds to step S107.

  In step S121, it is determined whether or not the difference between the slack amount and the slack amount initial value exceeds a preset threshold value R. However, this step is not always essential, and is always an ideal value (initial set value). It may be a flow for pursuing.

  As described above, according to the printing apparatus 1 according to the embodiment of the present invention, based on the abutting sound detected by the sound sensor 17 and the slack amount setting value set by the slack amount setting unit 80a, 1 The amount of rotation of the next paper feed rollers 12a and 12b is adjusted. Therefore, it is possible to accurately detect the timing at which the printing paper W hits the secondary paper feeding unit 14, and accordingly, the slack amount setting value can be set to the minimum necessary for skew correction, so that printing can be performed appropriately. The skew correction of the paper W can be performed and the printing productivity can be increased.

  In the example shown in FIG. 6, since the area S1 can be set to the minimum necessary, the skew correction of the printing paper W is appropriately performed, and the rotation start timing of the secondary paper feeding rollers 14a and 14b (T7) 6), that is, the time T shown in FIG. 6 can be shortened as much as possible, thereby increasing the productivity of printing.

  Further, according to the printing apparatus 1 according to the embodiment of the present invention, the loosening release sound detected by the sound sensor 17 and the vibration sensor 18 are detected from the time when the operations of the secondary paper feed rollers 12a and 12b are started. The actual amount of slack formed when the printing paper W hits the secondary paper feed unit 14 until the detected vibration is detected is calculated so that the actual amount of slack approaches the set slack amount initial value. In addition, based on the slack amount of the previous cycle, the slack amount initial value, and the abutting sound detected by the sound sensor 17, the feed amounts (rotational speed, rotational acceleration, operating time) of the primary paper feed rollers 12a and 12b ) Is adjusted, the slack amount can be calculated accurately, and the accurately calculated slack amount can be reflected in the control of the primary paper feed unit 12. Thereby, the printing apparatus 1 can perform skew correction of printing paper more appropriately.

  Furthermore, the printing apparatus 1 according to the embodiment of the present invention can also perform the idle feeding determination based on the abutment sound or the slack release sound detected by the sound sensor 17 or the vibration detected by the vibration sensor 18. . For example, if the sound sensor 17 or the vibration sensor 18 does not detect sound or vibration at a predetermined time after the rotation of the primary paper feed rollers 12a and 12b is detected by the control unit 80 of the printing apparatus 1, it is judged as idle feeding. Can be determined.

  In the above-described embodiment, the T8 is detected more reliably and both the sound sensor 17 and the vibration sensor 18 are used. However, in order to reduce the cost, one of the following may be used. good.

1) Whether the release sound of the sound sensor 17 is within a predetermined volume range stored in the ROM 72. 2) Whether the vibration of the vibration sensor 18 is within the predetermined vibration range of the ROM 72.
In the above two, a sound (second wave P1 in the detected value of the sound sensor shown in FIG. 6) generated when the paper breaks or a part of the apparatus contacts when slack is formed, and is generated in the other apparatus. If it cannot be distinguished from sound and vibration
3) In addition to either 1) or 2) above, T8 may be detected using whether or not the generation of the sound or vibration is after the operation of the secondary paper feed roller is started.

  Further, since the conveyance of the printing paper W can be reliably detected by the sound sensor 17 or the vibration sensor 18, the registration sensor 15 can be omitted.

  Note that in the printing apparatus 1 according to the embodiment of the present invention, the rotation amount adjustment unit 80c of the control unit 80 has a slack amount setting value in which the area S1 illustrated in FIG. 6 is a slack amount necessary for skew correction at least. The time point T6 at which the deceleration for stopping the rotation of the primary paper feed rollers 12a and 12b is started is determined so as to be S. However, the rotation amount adjustment unit 80c is not limited thereto, and the area S1 is the amount of slackness. The rotation speed V3 of the primary sheet feed rollers 12a and 12b after the time point T5 is calculated so as to be the set value S, and the primary sheet feed rollers 12a and 12b are controlled to rotate at the calculated rotation speed V3. You may do it. That is, the rotation amount adjusting unit 80c stops the rotation of the primary paper feed rollers 12a and 12b after time T5 (speed is zero) or changes the speed so that the area S1 becomes the slack amount setting value S. By controlling to do so, the rotation amount of the primary paper feed rollers 12a and 12b is adjusted.

  In the printing apparatus 1 according to the embodiment of the present invention, the case where single-sided printing is performed using the printing paper W stacked on the paper feed tray 11 has been described as an example. Similarly, when the paper size of the printing paper W stacked in any of the sections 22a, 22b, 22c, and 22d is selected, and when double-sided printing is selected and the front surface printing of the printing paper W is finished, In addition, the skew correction of the printing paper can be appropriately performed and the printing productivity can be increased.

  In addition, the printing apparatus 1 according to the embodiment of the present invention has been described by taking an inkjet line color printer that performs printing in line units as an example. However, the present invention is not limited thereto, and a serial inkjet system, a laser system, or a stencil is used. A printing apparatus such as a printing method may be used.

DESCRIPTION OF SYMBOLS 1 ... Printing apparatus 10 ... Side paper feed part 11 ... Paper feed stand 12 ... Primary paper feed part (1st paper feed means)
12a, 12b ... primary paper feed roller 12c ... primary paper feed drive mechanism 12d ... separating plate 14 ... secondary paper feed unit (second paper feed means)
14a, 14b ... secondary paper feed roller 14c ... secondary paper feed drive mechanism 15 ... registration sensor 17 ... sound sensor (sound detection means)
18 ... Vibration sensor (vibration detecting means)
20... Internal paper feeders 21 a, 21 b, 21 c, 21 d... Paper feeders 22 a, 22 b, 22 c, 22 d... Primary paper feeder (first paper feeder)
23a, 23b ... conveying roller 30 ... printing unit 40 ... paper discharge unit 50 ... reversing unit (first paper feeding means)
51. Reverse table (paper feed table)
52. Reverse roller (primary paper feed roller)
53a, 53b ... conveying roller 80 ... control unit 80a ... slack amount setting unit 80b ... slack amount calculation unit 80c ... rotation amount adjustment unit

Claims (5)

A first paper feed means for taking out and transporting the printing paper placed on the paper feed tray one by one;
A second paper feeding means for delivering the printing paper conveyed by the first paper feeding means to the printing means at a predetermined time;
The printing paper that is provided in the vicinity of the printing paper conveyance path between the first paper feeding means and the second paper feeding means and that is conveyed by the first paper feeding means is the second paper feeding. Detecting means for detecting a wave generated when hitting the means;
Control means for controlling the first paper feed means based on the wave detected by the detection means;
A printing apparatus comprising: The first paper feeding means
A primary paper feed roller is provided in the vicinity of the paper feed table, and by rotating the primary paper feed roller, the printing paper placed on the paper feed table is taken out and conveyed one by one,
The control means includes
A slack amount setting means for setting, as a slack amount setting value, a set value of a slack amount formed when the printing paper conveyed by the first paper feed means hits the second paper feed means;
Rotation amount adjustment means for adjusting the rotation amount of the primary paper feed roller based on the wave detected by the detection means and the sag amount setting value set by the sag amount setting means. The printing apparatus according to claim 1. A first paper feeding unit provided with a primary paper feeding roller in the vicinity of the paper feeding table, and rotating the primary paper feeding roller to take out and convey the printing paper placed on the paper feeding table one by one; ,
A secondary paper feed roller is provided on the print paper transport path, and the secondary paper feed roller is rotated so that the print paper transported by the first paper feed means is printed one by one at a predetermined time. A second paper feeding means for conveying to the printing means;
A detecting unit provided in the vicinity of a conveyance path of the printing paper between the first paper feeding unit and the second paper feeding unit and detecting a wave generated when the loosening of the printing paper is released; ,
Based on the wave generated when the slack detected by the detection means is released and the amount of rotation of the secondary paper feed roller, the printing paper is formed to abut against the second paper feed means. A slack amount calculating means for calculating a slack amount;
A rotation amount adjusting means for adjusting the rotation amount of the primary paper feed roller so that the slack amount calculated by the slack amount calculating means approaches a preset slack amount setting value;
A printing apparatus comprising: The detection means includes
Vibration detecting means for detecting at least one of vibration generated when the printing paper hits the second paper feeding means and vibration generated when the slack of the printing paper is released; and the printing At least one of sound detection means for detecting at least one of a sound generated when the paper hits the second paper supply means and a sound generated when the slack of the printing paper is released. The printing apparatus according to claim 1, comprising at least two. A first paper feeding unit provided with a primary paper feeding roller in the vicinity of the paper feeding table, and rotating the primary paper feeding roller to take out and convey the printing paper placed on the paper feeding table one by one; ,
A secondary paper feed roller is provided on the print paper transport path, and the secondary paper feed roller is rotated so that the print paper transported by the first paper feed means is printed one by one at a predetermined time. A second paper feeding means for conveying to the printing means;
The printing paper that is provided in the vicinity of the printing paper conveyance path between the first paper feeding means and the second paper feeding means and that is conveyed by the first paper feeding means is the second paper feeding. Sound detection means for detecting a squeezing sound generated when hitting the means and a loosening release sound when the looseness of the printing paper is released;
A vibration detecting means provided in the vicinity of the transport path of the printing paper between the first paper feeding means and the second paper feeding means, and detects a vibration generated when the looseness of the printing paper is released. When,
A slack amount setting means for setting, as a slack amount setting value, a set value of a slack amount formed when the printing paper conveyed by the first paper feed means hits the second paper feed means;
Based on the loosening release sound detected by the sound detection means, the vibration detected by the vibration detection means, and the rotational speed of the secondary paper feed roller, the printing paper is fed to the second paper feed means. A slack amount calculating means for calculating a slack amount formed by striking,
The slack amount calculated in the past by the slack amount calculating means and the slack setting value so that the slack amount calculated by the slack amount calculating means approaches the slack amount setting value set by the slack amount setting means. A rotation amount adjusting unit that adjusts the rotation amount of the primary paper feed roller based on the abutment sound detected by the sound detection unit;
A printing apparatus comprising:

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