Media transport device and media processing device using the same

Abstract

To provide a medium conveyance device capable of distinguishing the presence or absence of a wrinkle of a medium with a simple configuration in association with alignment of a tip position of the medium.SOLUTION: In one embodiment, a medium conveyance device comprises: alignment / conveyance means 1 which conveys a medium S after aligning a tip position of the medium S; upstream-side conveyance means 2 which is provided on the upstream side of the alignment / conveyance means 1 in a medium conveyance direction and conveys the medium S toward the alignment / conveyance means 1; a plurality of detection means 3 which are provided on the downstream side of the alignment / conveyance means 1 in the medium conveyance direction and detect timings when a tip or a rear end of the medium S passing through the alignment / conveyance means 1 passes at a plurality of places on a reference line L crossing the conveyance direction of the medium S; and discrimination means 4 which discriminates the presence or absence of a wrinkle of the medium S using detection results of the plurality of detection means 3. In another embodiment, the medium conveyance device comprises the discrimination means 4 which discriminates a skew state of a tip of the medium S in the conveyance direction and the presence or absence of a wrinkle of the medium S using the detection results of the plurality of detection means 3.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a medium conveyance device and a medium processing device using the same.

Background Art

[0002] Conventionally, as this type of medium conveyance device, for example, the one described in Patent Document 1 is already known. Patent Document 1 discloses a medium control method for a medium separation and feeding device that detects the surface state of a medium such as whether the medium being fed has wrinkles or not, combines the detected information on the surface state of the medium with the detected information on the running state of the medium when controlling the feeding state of the medium, and adjusts the meshing amount of the left and right feeding rollers and the separation roller according to the running state of the medium by different amounts according to the surface state of the medium.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technical problem to be solved by the present invention is to determine the presence or absence of wrinkles in a medium with a simple configuration in association with the alignment of the leading end position of the medium.

Means for Solving the Problems

[0005] A first technical feature of the present invention is an alignment conveyance means for conveying the medium after aligning the leading end position of the medium, an upstream conveyance means provided on the upstream side in the medium conveyance direction from the alignment conveyance means for conveying the medium toward the alignment conveyance means, and a downstream conveyance means provided on the downstream side in the medium conveyance direction from the alignment conveyance means for passing the medium through the alignment conveyance means at a plurality of locations on a reference line intersecting the conveyance direction of the medium Front and rear ends in the direction of transportThe media transport device is characterized by comprising a plurality of detection means for detecting the timing of when the signal is overflowing, and a determination means for determining whether or not the media is wrinkled using the detection results of the plurality of detection means.

[0006] A second technical feature of the present invention is an alignment conveying means for conveying a medium after aligning the leading edge position of the medium; an upstream conveying means provided upstream of the alignment conveying means in the medium conveying direction and conveying the medium toward the alignment conveying means; and a downstream of the alignment conveying means in the medium conveying direction and at multiple points on a reference line intersecting the conveying direction of the medium, the media passing through the alignment conveying means. Front and rear ends in the direction of transport The media transport device is characterized by comprising: a plurality of detection means for detecting the timing of when the medium is overflowing; and a determination means for determining the oblique state of the leading edge in the transport direction of the medium and the presence or absence of wrinkles in the medium using the detection results of the plurality of detection means.

[0007] A third technical feature of the present invention is a media conveying device having the first or second technical features, wherein the plurality of detection means share a detection means for detecting the oblique state of the leading edge of the media in the conveying direction. A fourth technical feature of the present invention is a media transport device having the first or second technical feature, wherein the plurality of detection means are provided immediately after passing the alignment transport means. A fifth technical feature of the present invention is a media transport device having the fourth technical feature, wherein all or part of the plurality of detection means are arranged separately near both ends in the width direction intersecting the transport direction of the media. 。 This invention 6 Its technical features are, The first or second In a media transport device having the following technical features, The aforementioned multiple detection means consist of two, The discriminant means is a media transport device characterized by determining that the media is wrinkled when the difference in the amount of inclination between the leading and trailing ends of the media in the transport direction and the reference line is greater than a predetermined threshold. 。 This invention 7 Its technical features are, The first or second In a media transport device having the following technical features, The aforementioned multiple detection means consist of three or more, The aforementioned determination means is a media conveying device characterized by determining that the media is wrinkled when the amount of inclination of the leading or trailing end of the media in the conveying direction with respect to the reference line is not uniform with respect to the width direction of the media. This invention 8 The technical features of the media transport device are as follows: In a media transport device having the first or second technical features, the determination means determines that the transport posture of the media is excessively skewed when the skewed state of the leading edge of the transport direction of the media exceeds a predetermined threshold, and determines whether or not there are wrinkles in the media when it is below the threshold. This invention 9 The technical features of the first 8 A media transport device having the above technical features, wherein the discrimination means determines whether or not the media is wrinkled when the media is a thin medium with a predetermined thickness or less. This invention 10 The technical feature of this media transport device is that, in a media transport device having the first or second technical feature, the device is equipped with a removal processing means that performs a removal process to remove the wrinkled media from the transport path when the discrimination means determines that the media is wrinkled. This invention 11 The technical features of the first 10 A media transport device having the above technical features, characterized in that when the discrimination means determines that the media is wrinkled, it is provided with a notification means that notifies the user that the media is wrinkled.

[0008] This invention 12 The technical features of the media processing apparatus are that it comprises a media transport device having the first or second technical features, and a processing means for performing a predetermined process on the media transported by the media transport device. [Effects of the Invention]

[0009] According to the first technical feature of the present invention, it is possible to determine the presence or absence of wrinkles in the medium with a simple configuration as the alignment of the leading end position of the medium is carried out. According to the second technical feature of the present invention, it is possible to determine the skewed state of the medium and the presence or absence of wrinkles in the medium with a simple configuration as the alignment of the leading end position of the medium is carried out. According to the third technical feature of the present invention, it is possible to determine the presence or absence of wrinkles in the medium by sharing a detection means for detecting the skewed state of the medium as the alignment of the leading end position of the medium is carried out. According to the fourth technical feature of the present invention, it is possible to grasp the skewed state and the presence or absence of wrinkles of the aligned medium earlier compared to the case where a plurality of detection means are provided away from the alignment conveyance means. According to the fifth technical feature of the present invention, it is possible to detect the position information of the leading end or the trailing end in the conveyance direction of the medium over a wide range. 。 According to the 6 technical feature of the present invention, Using two detection methods, By paying attention to the difference in the inclination amounts of the leading end and the trailing end in the conveyance direction of the medium, it is possible to determine the presence or absence of wrinkles in the medium. 。 According to the 7 technical feature of the present invention, Using three or more detection means, By paying attention to whether the inclination amount of the leading end or the trailing end in the conveyance direction of the medium is uniform with respect to the width direction of the medium, it is possible to determine the presence or absence of wrinkles in the medium. According to the 8 technical feature of the present invention, it is possible to avoid a wasteful situation of checking the presence or absence of wrinkles in a medium with excessive skew when monitoring the conveyance state of the medium. According to the 9 technical feature of the present invention, it is possible to check the presence or absence of wrinkles only for a thin medium in which wrinkles are likely to occur during conveyance of the medium. According to the 10 technical feature of the present invention, it is possible to easily remove a medium with wrinkles from the conveyance path. According to the 11 technical feature of the present invention, it is possible to inform the user that a medium with wrinkles exists in the conveyance path. According to the12 According to the technical features, it is possible to provide a media processing apparatus including a media conveyance apparatus capable of determining the presence or absence of wrinkles in a media with a simple configuration in accordance with the alignment of the leading end position of the media.

Brief Description of the Drawings

[0010] [Figure 1] (a) is an explanatory diagram showing an overview of an embodiment of a media processing apparatus incorporating a media conveyance apparatus to which the present invention is applied, (b) is an explanatory diagram showing a configuration example of a plurality of detection means when the media conveyance apparatus shown in (a) is viewed from the B direction, and (c) is an explanatory diagram showing another configuration example of the plurality of detection means. [Figure 2] It is an explanatory diagram showing the overall configuration of an image forming apparatus as a media processing apparatus according to Embodiment 1. [Figure 3] It is an explanatory diagram showing a main part of a media conveyance apparatus used in the image forming apparatus according to Embodiment 1. [Figure 4] (a) shows a configuration example of a position sensor used in the media conveyance apparatus according to Embodiment 1, and (b) is an explanatory diagram showing a configuration example of a position sensor used in the media conveyance apparatus according to Embodiment 2. [Figure 5] It is a flowchart showing the paper wrinkle determination process of the media conveyance apparatus according to Embodiment 1. [Figure 6] (a) is an explanatory diagram showing the relative positional relationship between the paper during normal conveyance and two position sensors, (b) is an explanatory diagram showing the relative positional relationship between the paper during skew conveyance and two position sensors, and (c) is an explanatory diagram showing the relative positional relationship between the paper with wrinkles and two position sensors. [Figure 7] (a) is an explanatory diagram showing an output example of two position sensors with respect to the paper during normal conveyance (FIG. 6(a)), (b) is an explanatory diagram showing an output example of two position sensors with respect to the paper during skew conveyance (FIG. 6(b)), and (c) is an explanatory diagram showing an output example of two position sensors with respect to the paper with wrinkles (FIG. 6(c)). [Figure 8] It is a flowchart showing the paper wrinkle determination process of the media conveyance apparatus according to Embodiment 2. [Figure 9](a) is an explanatory diagram showing the relative positional relationship between the paper and the three position sensors during normal transport, (b) is an explanatory diagram showing the relative positional relationship between the paper and the three position sensors during skewed transport, and (c) is an explanatory diagram showing the relative positional relationship between the wrinkled paper and the three position sensors. [Figure 10] (a) is an explanatory diagram showing an example of a paper wrinkle pattern that can be distinguished in both Embodiment 1 and Embodiment 2, and (b) is an explanatory diagram showing an example of a paper wrinkle pattern that is difficult to distinguish in Embodiment 1 but can be distinguished in Embodiment 2. [Figure 11] (b) is an explanatory diagram showing an example of the output of three position sensors for paper during normal transport (Figure 9(a)), (c) is an explanatory diagram showing an example of the output of three position sensors for paper during skewed transport (Figure 9(b)), (d) is an explanatory diagram showing an example of the output of three position sensors for paper with wrinkles (Figure 9(c)), and (d) is an explanatory diagram showing an example of the output of three position sensors for paper with wrinkles (Figure 10(a)). [Modes for carrying out the invention]

[0011] ◎Overview of the Embodiment Figure 1(a) is an explanatory diagram illustrating an overview of an embodiment of a media processing apparatus incorporating a media transport device to which the present invention is applied. In the figure, the media processing device comprises a media transport device 10 for transporting the media S, and a processing means 11 for performing predetermined processing on the media S transported by the media transport device 10. In this example, a typical configuration of the media transport device 10 includes: an alignment transport means 1 that transports the media S after aligning the leading edge position of the media S; an upstream transport means 2 provided upstream of the alignment transport means 1 in the media transport direction and transporting the media S toward the alignment transport means 1; and a downstream of the alignment transport means 1 in the media transport direction and at multiple points on a reference line L that intersects the transport direction of the media S, the media S passing through the alignment transport means 1. Front and rear ends in the direction of transport The system includes multiple detection means 3 for detecting the timing of when the signal passes, and a determination means 4 for determining whether or not there are wrinkles in the medium S using the detection results of the multiple detection means 3.

[0012] Another typical configuration of the media transport device 10 includes an alignment transport means 1 that transports the media S after aligning the leading edge position of the media S, an upstream transport means 2 provided upstream of the alignment transport means 1 in the media transport direction and transporting the media S toward the alignment transport means 1, and a plurality of alignment transport means provided downstream of the alignment transport means 1 in the media transport direction and intersecting a reference line L in the transport direction of the media S at multiple points. 1 The medium S passing through Front and rear ends in the direction of transport Multiple detection means 3 for detecting the timing of when the signal is exceeded, and using the detection results of the multiple detection means 3 to determine the oblique state of the leading edge in the transport direction of the medium S and Medium S It is equipped with a discrimination means 4 for determining whether or not there are wrinkles. In other words, a typical example of the former is a method of determining the presence or absence of wrinkles in the medium S using multiple detection means 3, while a typical example of the latter is a method of determining the skewed state of the medium S and the medium S This is used to determine whether or not there are wrinkles.

[0013] In such technical means, the alignment method of the alignment conveying means 1 may be any known method, including a method in which the leading edge of the medium S is aligned along the alignment rolls by stopping the pair of alignment rolls to block the leading edge of the medium S and releasing the pinching state (nip) of the medium S by the upstream conveying means 2. Furthermore, the multiple detection means 3 can be selected as appropriate, including optical and mechanical types, as long as they are capable of detecting the timing of the leading and trailing ends of the medium S passing over them. Also, as shown in Figures 1(b) and 1(c), the multiple detection means 3 only need to be provided corresponding to multiple points on the reference line L, and do not include line sensors that can detect continuously. Furthermore, the discrimination means 4 broadly includes methods for determining the skewed state and the presence or absence of wrinkles in the medium S.

[0014] Next, a typical or preferred configuration of the media transport device 10 in this embodiment will be described. First, a typical example of multiple detection means 3 is one in which a detection means for detecting the skewed state of the leading edge of the medium S in the transport direction is shared. In this example, if the medium transport device 10 is already equipped with a detection means for detecting the skewed state of the leading edge of the medium S in the transport direction, there is no need to use a dedicated detection means for determining whether or not there are paper wrinkles in the medium S, and the cost of multiple detection means 3 can be reduced accordingly. Furthermore, from the viewpoint of early detection of the skewed state of the medium S and the presence or absence of wrinkles in the medium S, it is preferable that the multiple detection means 3 be provided immediately after passing the alignment transport means 1. In this example, from the viewpoint of detecting the positional information of the leading or trailing end of the medium S in the transport direction over a wide area, it is preferable that all or some of the multiple detection means 3 are arranged separately near both ends in the width direction intersecting the transport direction of the medium S.

[0015] Furthermore, preferred embodiments of the multiple detection means 3 as As shown in Figure 1(b), there are two detection means 3 (specifically 3a and 3b), which detect the timing of the leading and trailing ends of the medium S passing in the transport direction. In this case, the discrimination means 4 should determine that the medium S is wrinkled when the difference in the amount of inclination of the leading and trailing ends of the medium S with respect to the reference line L is greater than a predetermined threshold. Furthermore, another preferred configuration of the multiple detection means 3 is as shown in Figure 1(c), where there are three or more detection means 3 (for example, 3a to 3c), and they detect the timing of the leading and trailing ends of the medium S passing in the transport direction. In this case, the discrimination means 4 should determine that the medium S is wrinkled when the amount of inclination of the leading or trailing end of the medium S with respect to the reference line L is not uniform with respect to the width direction of the medium S.

[0016] Furthermore, a preferred embodiment of the discrimination means 4 is one in which the transport posture of the medium S is determined to be excessively skewed when the skewed state of the leading edge of the medium S in the transport direction exceeds a predetermined threshold, and the presence or absence of wrinkles in the medium S is determined when it is below the threshold. In this case, it is acceptable to determine the presence or absence of wrinkles for all medium S, but considering that wrinkles are more likely to occur when the medium S is a thin medium with a predetermined thickness or less, it is also acceptable to determine the presence or absence of wrinkles in the medium S only when the medium S is a thin medium with a predetermined thickness or less.

[0017] Furthermore, when the discrimination means 4 determines that the medium S is wrinkled, the system may also include a removal processing means 6 that performs a removal process to remove the wrinkled medium S from the transport path. The removal processing means 6 here includes a method of stopping the transport of the medium S in a transport stop mode and having the user remove it, and a method of discharging it to another discharge and storage means in a transport continuation mode. Furthermore, when the discrimination means 4 determines that the medium S is wrinkled, the system may also include a notification means 7 that notifies the user that the medium S is wrinkled.

[0018] The present invention will be described in further detail below based on the embodiments shown in the attached drawings. ◎Embodiment 1 Figure 2 is an explanatory diagram showing the overall configuration of an image forming apparatus as a media processing apparatus according to Embodiment 1. -Overall configuration of the image forming apparatus- In the figure, the basic configuration of the image forming apparatus is such that an image forming engine 21 for producing multiple color component images is mounted inside the apparatus housing 20, and below the image forming engine 21 is a medium transport system 80 for transporting a medium to the image forming engine 21, and a fixing device 70 for fixing the image produced by the image forming engine 21 onto the medium. In this example, the image forming engine 21 includes an image forming unit 22 (specifically 22a to 22d) that forms an image of general colors with multiple color components (yellow (Y), magenta (M), cyan (C), and black (K) in this embodiment), a belt-shaped intermediate transfer body 30 that sequentially transfers (primary transfer) and holds each color component image formed in each image forming unit 22, and a secondary transfer device (batch transfer device) 50 that performs secondary transfer (batch transfer) of each color component image transferred onto the intermediate transfer body 30 to a medium (paper or film). In Figure 2, reference numeral 40 denotes an operation panel for operating the image forming apparatus.

[0019] -Image Forming Unit- In this embodiment, each image forming unit 22 (22a to 22d) has a drum-shaped photoreceptor 23, and around each photoreceptor 23 are provided a charging device 24 such as a Corotron or transfer roll for charging the photoreceptor 23, an exposure device 25 such as a laser scanning device for writing an electrostatic latent image onto the charged photoreceptor 23, a developing device 26 for developing the electrostatic latent image written on the photoreceptor 23 with YMCK color component toners, a primary transfer device 27 such as a transfer roll for transferring the toner image on the photoreceptor 23 to an intermediate transfer body 30, and a photoreceptor cleaning device 28 for removing residual toner from the photoreceptor 23. Furthermore, the intermediate transfer body 30 is stretched across multiple (three in this embodiment) tension rolls 31 to 33. For example, tension roll 31 is used as a drive roll driven by a drive motor (not shown), and the intermediate transfer body is circulated by this drive roll. In addition, an intermediate transfer body cleaning device 35 is provided between tension rolls 31 and 33 to remove residual toner from the intermediate transfer body 30 after secondary transfer.

[0020] -Secondary Transfer Device (Batch Transfer Device)- Furthermore, the secondary transfer device (bulk transfer device) 50 is configured such that, for example, a transfer roll 55 is pressed against the portion of the intermediate transfer body 30 facing the tension roll 33, and the tension roll 33 of the intermediate transfer body 30 is used as a counter roll 56 that acts as the counter electrode for the transfer roll 55. In this example, the transfer roll 55 has a metal shaft covered with an elastic layer made of foamed urethane rubber or EPDM mixed with carbon black, etc. A transfer voltage from a transfer power supply (not shown) is applied to the counter roll 56 (which in this example also serves as the tension roll 33) via a conductive power supply roll (not shown), while the transfer roll 55 is grounded to form a predetermined transfer electric field between the transfer roll 55 and the counter roll 56, so that the nip region of the intermediate transfer body 30 sandwiched between the transfer roll 55 and the counter roll 56 functions as a secondary transfer region (bulk transfer region) TR. Furthermore, although the secondary transfer device 50 uses a transfer roll 55, it is not limited to this configuration, and a transfer belt module in which a transfer belt is stretched across the transfer roll 55 as one of the tensioned rolls may also be used.

[0021] - Fixing device - The fixing device 70 includes a driveable and rotatable heated fixing roll 71 positioned in contact with the image-holding surface of the medium, and a pressurized fixing roll 72 positioned in pressure opposite the heated fixing roll 71 and rotating in accordance with the heated fixing roll 71. The image held on the medium is passed through the fixing region between the two fixing rolls 71 and 72, and the image is heated and pressed to fix it. Here, the heating and fixing roll 71 is configured such that, for example, a heater is built into the roll body, or the roll body is heated by contacting an external heater with the outer surface of the roll body. It is also possible to add a heater to the pressure fixing roll 72 as needed. This example shows an example of a roll pair configuration, but it is not limited to this, and the heating and fixing roll 71 may be configured as appropriate, for example, with a heating and fixing belt employing an electromagnetic induction heating method.

[0022] -Media transport system- Furthermore, the media transport system 80 has multiple stages (two stages in this example) of media supply containers 81 and 82. The media supplied from either of the media supply containers 81 or 82 is transported from a vertical transport path 83 extending in a substantially vertical direction to a horizontal transport path 84 extending in a substantially horizontal direction, and then to the secondary transfer area TR. After that, the media holding the transferred image is transported via a transport belt 85 to the fixing area by the fixing device 70, and then discharged to a media discharge receiver 86 provided on the side of the device housing 20. Furthermore, the media transport system 80 has a reversible branch transport path 87 that branches downward from the portion of the horizontal transport path 84 located downstream of the fixing device 70 in the media transport direction. The media that has been reversed in the branch transport path 87 is returned to the horizontal transport path 84 via the return transport path 88, and an image is transferred to the back surface of the media in the secondary transfer area TR. The media is then discharged to the media discharge receiver 86 via the fixing device 70. In addition, the branch transport path 87 is provided with a branch return transport path 89 that branches off midway and transports the reversed media to the media discharge receiver 86. Furthermore, the media transport system 80 includes a position-aligning roll 90 as a position-aligning transport means for supplying the media to the secondary transfer area TR with the media aligned in position, and an appropriate number of transport rolls 91 are provided in each transport path 83, 84, 87, 88, and 89. In addition, a manual feed medium dispenser 92 is provided on the opposite side of the media discharge receiver 86 of the device housing 20, which allows manual feed medium to be supplied toward the horizontal transport path 84.

[0023] -The necessity of determining whether or not there are wrinkles in the paper- In this type of image forming apparatus, there is a need to widely use paper of varying thicknesses (from thick to thin) as a medium. In response to this need, there has been concern about the occurrence of paper wrinkles when using thin paper of 80 gsm or less, and especially thin paper of 60 gsm or less. Regarding this type of paper wrinkle defect, methods have already been provided, such as placing an ILS (Image Line Sensor) in the media transport path to inspect for paper wrinkles in the passing media, or introducing an automated inspection device to check for the presence or absence of paper wrinkles in the output discharged to the media discharge tray. However, installing an ILS requires selecting horizontal transport paths and other components to improve inspection accuracy, which imposes limitations on the installation location. Furthermore, ILS units are large and expensive. In addition, automated inspection devices inspect the output of the media, requiring them to be retrofitted to the image forming machine, resulting in bulky installation spaces, large size, and high costs. Therefore, in this embodiment, we considered adopting an inexpensive method for determining the presence or absence of paper wrinkles by effectively utilizing existing media transport device configurations.

[0024] -Basic configuration of a media transport device- In this embodiment, as shown in Figures 2 and 3, the media transport device 100 has a basic configuration that aligns the leading edge position of the media S when transporting it to the secondary transfer area TR, so that the transport orientation of the media S is not oblique when it reaches the secondary transfer area TR. In this example, the media transport device 100 of this type includes a position alignment roll 90 as a position alignment transport means for aligning the leading edge position of the media S, a transport roll 91f(91) as an upstream transport means positioned upstream of the position alignment roll 90 in the transport direction of the media S, and two position sensors 110 (specifically 111, 112) provided downstream of the position alignment roll 90 in the transport direction of the media S as a plurality of detection means for detecting whether the leading edge of the media S that has passed through the position alignment roll 90 is in an oblique state.

[0025] <Position Alignment Roll> The position-aligning roll 90 corresponds to a so-called register roll and comprises a drive roll 121 having a roll body around a rotating shaft, and a driven roll 122 that rotates in contact with the drive roll 121 and has a roll body around a rotating shaft. A drive motor 123 is driven and connected to the drive roll 121 via a drive transmission component (not shown). The driven roll 122 is supported by a nip release mechanism 124 and can move toward and away from the drive roll 121 (nip release), forming a contact area (nip area) between the drive roll 121 and the driven roll 121 to hold the medium S, while also being able to move to a retracted position away from the contact area. When aligning the leading edge of the medium S, the nip state of the driven roll 122 relative to the drive roll 121 is maintained, and the drive of the drive roll 121 by the drive motor 123 is temporarily suspended. <Conveyor Roll> The transport roll 91f, like the position-aligning roll 90, includes a drive roll 131 and a driven roll 132. The drive roll 131 is driven and connected to a drive motor 133 via a drive transmission component (not shown), and the driven roll 132 is supported by a nip release mechanism 134.

[0026] <Position sensor> In this example, as shown in Figures 3 and 4(a), the position sensors 110(111,112) are installed at multiple locations (two locations in this example) along a reference line L that intersects the transport direction of the medium S, immediately after passing the position alignment roll 90 (at a distance m from the position alignment roll 90 in this example). The position sensors 110(111,112) in this example are positioned separately near both ends in the width direction that intersects the transport direction of the medium S, and the width dimension w between the two, including the position sensors 111,112, is set to be shorter than the width dimension of the usable size medium S, making it possible to detect the timing when the leading or trailing end of the medium S passes over the position alignment roll 90. Here, the position sensor 110 (111, 112) is an optical sensor having a light-emitting part and a light-receiving part. When the medium S passes by, the light-receiving part detects the reflected light from the light-emitting part, so that the boundary between the area from the leading end to the trailing end of the medium S in the transport direction and the other area appears as a change in the output of the light-receiving part. In addition to optical sensors, mechanical sensors or electrical sensors can also be used as the position sensor 110, as long as they can determine the positions of the leading and trailing ends of the medium S in the transport direction.

[0027] -Control system for media transport equipment- In this example, as shown in Figure 3, a control device 150 is provided for determining whether or not there are wrinkles in the paper medium S. This control device 150 is composed of a microcomputer that includes various processors. The term "processor" here refers to a processor in a broad sense, and includes general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and specialized processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0028] In this example, the control device 150 pre-installs necessary programs such as a program for the position alignment operation of the medium S and a "program for determining the presence or absence of paper wrinkles (see Figure 5)" in a memory not shown. After performing the position alignment operation of the medium S (corresponding to the alignment (register) operation by the position alignment roll 90), the device takes in detection information from the position sensors 110 (111, 112) as the medium S passes through the position alignment roll 90, executes the "program for determining the presence or absence of paper wrinkles," and determines whether the medium S has paper wrinkles.

[0029] <Media position alignment operation> As shown in Figure 5, before determining whether or not the media S has paper wrinkles, a position alignment operation of the media S is performed by the position alignment roll (register roll) 90. This involves stopping the drive of the position alignment roll 90 while it is in a nip state, transporting the media S with the transport roll 91f to bring the leading edge of the media S against the position alignment roll 90, and correcting the skew so that the leading edge of the media S is aligned with the axial direction of the position alignment roll 90. <Resumption of media transport operation> Once the aforementioned position alignment operation of the medium S is complete, the transport operation of the aligned medium S is resumed by the position alignment roll 90. Then, when the leading edge of the medium S passes the reference line L, it passes the position sensors 110 (111, 112). Here, the position sensors 110 (111, 112) detect the tip skew of the medium S, and determine whether the tip skew amount is below a predetermined threshold T0. The threshold T0 here refers to the tip skew amount at which the medium S is excessively oblique and difficult to travel. If the threshold T0 is exceeded, the transport operation of the medium S is stopped, and "Skew abnormality" is displayed on the display unit 151 of the control device 150.

[0030] If the leading edge skew of the medium S is less than or equal to the threshold T0, the trailing edge of the medium S passes the position sensor 110(111,112) when it crosses the reference line L. As a result, the position sensor 110(111,112) detects the trailing edge skew of the medium S, calculates the difference between the leading edge skew and the trailing edge skew of the medium S (skew difference), and determines whether this skew difference is less than or equal to a predetermined threshold ΔT. Here, under the condition that the skew difference is less than or equal to the threshold ΔT, normal transport operation is performed, and under the condition that the skew difference exceeds the threshold ΔT, it is treated as if paper wrinkles exist in the medium S. In this case, the threshold ΔT for the skew difference refers to the case where the timing at which the position sensors 110 (111,112) pass over the leading and trailing ends of the medium S differs between the leading and trailing ends. If this difference is within an acceptable range, it is acceptable to determine that there are no paper wrinkles. However, it is advisable to determine the presence or absence of "paper wrinkles" by considering cases where this difference exceeds a threshold that is likely to lead to the occurrence of paper wrinkles. In this example, if the transport stop mode is selected, the transport operation of the medium S is stopped, and the display unit 151 of the control device 150 displays "Paper wrinkles present". On the other hand, assuming that the transport stop mode is not selected, the transport continuation mode is performed, and the paper wrinkled medium is discharged to a separate medium discharge receiver (not shown).

[0031] -Relationship between position sensor output and paper wrinkle detection- (1) Normal transport As shown in Figure 6(a), assuming that the medium S1(S) is being transported normally, the timing at which the position sensors 110 (111, 112) pass the leading and trailing ends of the medium S1 will be the same, as shown in Figure 7(a), and this output pattern allows us to determine that the medium S1 is being transported normally. (2) Inclined transport This skewed transport method is primarily intended for cases of excessive skew, which can lead to the aforementioned skew abnormalities. As shown in Figure 6(b), assuming that the medium S2(S) is skewed and being transported at an angle, as shown in Figure 7(b), the timing at which the position sensors 110(111,112) pass the leading and trailing ends of the medium S will be shifted by the same amount of time Δt, and this output pattern allows us to determine that the medium S2 is being transported at an angle.

[0032] (3) Paper is wrinkled As shown in Figure 6(c), assuming that a paper wrinkle NG exists on either side in the width direction near the rear end of the medium S3(S), as shown in Figure 7(c), the timing at which the position sensor 110 (111,112) passes the front and rear ends of the medium S will be the same at the front end, but will be shifted by time Δt at the rear end. This output pattern allows for the determination that a paper wrinkle NG exists in the medium S. In this example, the paper wrinkle NG is located near the trailing end of the medium S. However, even if it were located near the leading end of the medium S, an output pattern with a time Δt difference would be obtained at the leading end, allowing for the determination that the paper wrinkle NG is present in the medium S.

[0033] -In combination with a media type discriminator- In this example, the process of determining the presence or absence of paper wrinkles is performed for all media S, but this is not limited to this. For example, as shown by the dashed lines in Figure 3, the media type determination information from the media type discriminator 160 is taken into the processor, and the presence or absence of paper wrinkles is determined only when the media S is thin, such as thin paper. The media type discriminator 160 referred to here includes a thickness detector that directly detects whether the media S is thin paper or thick paper other than thin paper, and a media designator that prepares a table of usable media types in the memory of the control device 150 and specifies the media S to be used from this media type table. The media type information determined based on this information should be taken into the control device 150.

[0034] ◎Embodiment 2 Figure 4(b) shows the main parts of the media transport device according to Embodiment 2. In the figure, the media transport device 100 is equipped with the same position alignment roll 90 and transport roll 91f as in Embodiment 1, but the configuration of the position sensor 110 (three in this example, 111-113) and the process for determining the presence or absence of paper wrinkles based on the detection output of the position sensor 110 are different. Components similar to those in Embodiment 1 are denoted by the same reference numerals as in Embodiment 1, and their detailed descriptions are omitted here. In the figure, as shown in Figures 3 and 4(b), the position sensors 110 (111-113) are installed at multiple locations (three locations in this example) on a reference line L that runs along the width direction intersecting the transport direction of the medium S, immediately after passing the position alignment roll 90 (at a distance m from the position alignment roll 90 in this example). In this example, the position sensors 110 (111, 112) are positioned separately near both ends in the width direction intersecting the transport direction of the medium S, similar to Embodiment 1, and the width dimension w between the two, including position sensors 111 and 112, is set to be shorter than the width dimension of the usable medium S. Furthermore, position sensor 110 (specifically 113) is installed midway between the position sensors 111 and 112 on both sides, approximately corresponding to the center of the medium S in the width direction. Therefore, in this example, the three position sensors 110 (111-113) are able to detect the timing when the leading or trailing end of the medium S passes over the position alignment roll 90.

[0035] -Control system for media transport equipment- In this example, the control device 150 pre-installs necessary programs such as a program for the position alignment operation of the medium S and a "program for determining the presence or absence of paper wrinkles (see Figure 8)" in a memory not shown. After performing the position alignment operation of the medium S (corresponding to the alignment (register) operation by the position alignment roll 90), the device takes in detection information from the position sensors 110 (111-113) as the medium S passes through the position alignment roll 90 and then passes through the position sensors 110 (111-113), executes the "program for determining the presence or absence of paper wrinkles," and determines whether the medium S has paper wrinkles.

[0036] <Media position alignment operation> As shown in Figure 8, before determining whether or not the media S has paper wrinkles, a position alignment operation of the media S is performed using a position alignment roll (register roll) 90, similar to that in Embodiment 1. <Resumption of media transport operation> Once the aforementioned position alignment operation of the medium S is complete, the transport operation of the aligned medium S is resumed by the position alignment roll 90. Then, when the tip of the medium S passes the reference line L, it passes the position sensors 110 (111-113). Here, similar to Embodiment 1, it is determined whether the tip skew amount is less than or equal to a predetermined threshold T0, and if it exceeds the threshold T0, a determination is made as to whether or not there is a skew abnormality.

[0037] Then, if the leading edge skew of the medium S is less than or equal to the threshold T0, the rear end of the medium S passes the position sensor 110 (111-113) when it passes the reference line L. As a result, the position sensor 110 (111-113) detects the rear end skew of the medium S, and by looking at the leading edge skew and rear end skew of the medium S, it is determined whether the inclination of the leading edge and rear end of the medium S is uniform or not. Here, under the condition that the inclination of the leading and trailing ends of the medium S is uniform, a normal transport operation is performed; under the condition that the inclination of the leading and trailing ends of the medium S is not uniform, the medium S is treated as having paper wrinkles. In this example, if the transport stop mode is selected, the transport operation of the medium S is stopped, and "Paper wrinkles present" is displayed on the display unit 151 of the control device 150. On the other hand, assuming that the transport stop mode is not selected, the transport continuation mode is implemented, and the paper-wrinkled medium is discharged to another medium discharge receiver (not shown).

[0038] -Relationship between position sensor output and paper wrinkle detection- (1) Normal transport As shown in Figure 9(a), assuming that the medium S1(S) is being transported normally, the timing at which the position sensors 110 (111~113) pass the leading and trailing ends of the medium S1 will be the same, as shown in Figure 11(a), and this output pattern allows us to determine that the medium is being transported normally. (2) Inclined transport This skewed transport method is primarily intended for cases of excessive skew, which can lead to the aforementioned skew abnormalities. As shown in Figure 9(b), assuming that the medium S2(S) is skewed and being transported at an angle, as shown in Figure 11(b), the timing at which the position sensors 110 (111~113) pass the leading and trailing ends of the medium S2 will be shifted by the same amount of time Δt, and this output pattern allows us to determine that the medium S2 is being transported at an angle.

[0039] (3) Paper is wrinkled As shown in Figure 9(c), assuming that a paper wrinkle NG exists in the widthwise center near the rear end of the medium S3(S), as shown in Figure 11(c), the timing at which the position sensors 110 (111~113) pass the front and rear ends of the medium S will be the same at the front end, but at the rear end, position sensor 113 will be delayed by time Δt earlier than position sensors 111 and 112. This output pattern allows for the determination that a paper wrinkle exists in the medium S3. Furthermore, in this example, the position sensors 110 (111-113) are arranged in three locations: on both sides and in the center of the width direction of the medium S. Therefore, as shown in Figure 10(a), even if the paper wrinkle NG is located on either side near the rear end of the medium S, as shown in Figure 11(d), the position sensor 112 at the rear end will shift earlier than the position sensors 111 and 113 by time Δt, and this output pattern allows for the determination that a paper wrinkle exists in the medium S.

[0040] Thus, in this embodiment, as shown in Figures 10(a) and 10(b), even if the paper wrinkle NG is located on either side in the width direction near the rear end of the medium S, or in the center in the width direction, the presence of the paper wrinkle NG can be determined in either case. In this respect, in Embodiment 1, when the paper wrinkle NG is located near the center in the width direction near the rear end of the medium S, the two position sensors 110 (111, 112) tend to have difficulty detecting the time Δt difference. Therefore, this embodiment is preferable to Embodiment 1 in that it has a higher accuracy in determining the paper wrinkle NG. In this example, the paper wrinkle NG is located near the trailing end of the medium S. However, even if it were located near the leading end of the medium S, an output pattern with a time Δt difference would be obtained at the leading end, allowing for the determination that the paper wrinkle NG is present in the medium S. Furthermore, in this embodiment as well, similar to Embodiment 1, media type information from the media type discriminator 160 may be input to the control device 150, and the process of determining whether or not there are paper wrinkles may be performed only for thin media S such as thin paper. Furthermore, by installing more than three position sensors 110, it is possible to further improve the accuracy of paper wrinkle detection. [Explanation of symbols]

[0041] 1…Alignment and conveying means, 2…Upstream conveying means, 3(3a~3c)…Detection means, 4…Discrimination means, 6…Removal processing means, 7…Notification means, 10…Media conveying device, 11…Processing means, S…Media, L…Reference line

Claims

1. A positioning and transporting means for transporting the medium after aligning the leading edge position of the medium, An upstream conveying means is provided upstream of the alignment conveying means in the media conveying direction and conveys the media toward the alignment conveying means, Multiple detection means are provided downstream of the alignment conveying means in the media conveying direction, and detect the timing at which the leading and trailing ends of the media in the conveying direction pass over multiple points on a reference line that intersects the conveying direction of the media as it passes through the alignment conveying means. A determination means for determining whether or not the medium has wrinkles using the detection results of the plurality of detection means, A media transport device characterized by being equipped with the following features.

2. A positioning and transporting means for transporting the medium after aligning the leading edge position of the medium, An upstream conveying means is provided upstream of the alignment conveying means in the media conveying direction and conveys the media toward the alignment conveying means, Multiple detection means are provided downstream of the alignment conveying means in the media conveying direction, and detect the timing at which the leading and trailing ends of the media in the conveying direction pass over multiple points on a reference line that intersects the conveying direction of the media as it passes through the alignment conveying means. A determination means for determining the oblique state of the leading edge of the medium in the transport direction and the presence or absence of wrinkles in the medium using the detection results of the plurality of detection means, A media transport device characterized by being equipped with the following features.

3. In the media transport device according to claim 1 or 2, A media transport device characterized in that the plurality of detection means share a detection means for detecting the oblique state of the leading edge of the medium in the transport direction.

4. In the media transport device according to claim 1 or 2, The media transport device is characterized in that the plurality of detection means are provided immediately after passing the alignment transport means.

5. In the media transport device according to claim 4, A media transport device characterized in that all or some of the plurality of detection means are arranged separately near both ends in the width direction intersecting the transport direction of the media.

6. In the media transport device according to claim 1 or 2, The aforementioned multiple detection means consist of two, The media transport device is characterized in that the determination means determines that the media is wrinkled when the difference in the amount of inclination between the leading and trailing ends of the media in the transport direction and the reference line is greater than a predetermined threshold.

7. In the media transport device according to claim 1 or 2, The aforementioned multiple detection means consist of three or more, The media transport device is characterized in that the determination means determines that the media is wrinkled when the amount of inclination of the leading or trailing end of the media in the transport direction with respect to the reference line is not uniform with respect to the width direction of the media.

8. In the media transport device according to claim 1 or 2, The media transport device is characterized in that the determination means determines that the transport posture of the media is excessively skewed when the skewed state of the leading edge of the media in the transport direction exceeds a predetermined threshold, and determines whether or not there are wrinkles in the media when it is below the threshold.

9. In the media transport device according to claim 8, The media transport device is characterized in that the determination means determines whether or not the media is wrinkled when the media is a thin medium with a predetermined thickness or less.

10. In the media transport device according to claim 1 or 2, A media transport device characterized by comprising a removal processing means for performing a removal process to remove the wrinkled media from the transport path when the discrimination means determines that the media is wrinkled.

11. In the media transport device according to claim 10, A media transport device characterized by comprising a notification means for notifying that the media is wrinkled when the determination means determines that the media is wrinkled.

12. A media transport device according to claim 1 or 2, Processing means for performing predetermined processing on the medium being transported by the medium transport device, A media processing apparatus characterized by comprising:

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