This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application No. 2018-020986, filed on Feb. 8, 2018, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.
This disclosure relates to an image forming apparatus that corrects positional deviations of a sheet and an image to be formed on the sheet and a method of correcting a positional deviation of a sheet.
Image forming apparatuses for forming an image on a sheet cause a positional deviation of a sheet during sheet conveyance, and therefore cause a positional deviation of an image to be formed on the sheet.
Such image forming apparatuses include a detecting mechanism that detects a position of a sheet in order to calculate the amount of positional deviation of the sheet so that the positional deviation of the sheet is corrected before image formation.
Known image forming apparatuses have proposed a technique in which a detecting mechanism including contact image sensors or skew detection sensors detects the position of a sheet and calculates the amount of positional deviation of the sheet. Then, based on the calculated amount of positional deviation of the sheet, a sheet gripping roller that grips the sheet conveys the sheet toward a downstream side in a sheet conveying direction while correcting the positional deviation of the sheet. Then, the sheet is conveyed to an image forming position where an image is formed on the sheet after the positional deviation of the sheet is corrected.
In a known image forming apparatus such as the known image forming apparatus that corrects the positional deviation of a sheet while conveying the sheet by a sheet conveying member such as the sheet gripping roller, it is expected that the positional deviation of the sheet is corrected during a time period from when the sheet reaches the sheet conveying member to when the sheet is conveyed to a downstream side roller. Therefore, in a case in which the sheet has a large amount of positional deviation, the known image forming apparatus cannot complete the correction of the positional deviation of the sheet while the sheet is being conveyed by the sheet gripping roller, and therefore the sheet is conveyed to the image forming position with the positional deviation. The above-described inconvenience may be solved by reducing the sheet conveying speed by the sheet conveying member. However, this reduction in the sheet conveying speed results in degradation in the productivity of the image forming apparatus.
At least one aspect of this disclosure provides an image forming apparatus including a detecting device, a pair of sheet conveying bodies, an image forming device, and circuitry. The detecting device is configured to detect a position of a sheet. The pair of sheet conveying bodies is configured to convey the sheet and correct a positional deviation of the sheet. The image forming device is configured to form an image on the sheet. The circuitry is configured to calculate a first positional deviation amount of the sheet based on a first detection result of the position of the sheet by the detecting device, cause the pair of sheet conveying bodies to correct the positional deviation of the sheet based on the first positional deviation amount, calculate a second positional deviation amount of the sheet based on a second detection result of the position of the sheet by the detecting device, and cause the image forming device to correct an image forming position on the sheet based on the second positional deviation amount.
Further, at least one aspect of this disclosure provides a method of correcting a positional deviation of a sheet, the method including detecting a position of the sheet by a plurality of image sensors, calculating a first positional deviation amount of the sheet based on a first detection result of the position of the sheet, causing a pair of sheet conveying bodies to correct the positional deviation of the sheet based on the first positional deviation amount, detecting the position of the sheet again, calculating a second positional deviation amount of the sheet based on a second detection result of the position of the sheet, and causing an image forming device to correct an image forming position on the sheet based on the second positional deviation amount.
An exemplary embodiment of this disclosure will be described in detail based on the following figured, wherein:
It will be understood that if an element or layer is referred to as being “on”, “against”, “connected to” or “coupled to” another element or layer, then it can be directly on, against, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, if an element is referred to as being “directly on”, “directly connected to” or “directly coupled to” another element or layer, then there are no intervening elements or layers present. Like numbers referred to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper” and the like may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements describes as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, term such as “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors herein interpreted accordingly.
Although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, it should be understood that these elements, components, regions, layer and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure.
The terminology used herein is for describing particular embodiments and examples and is not intended to be limiting of exemplary embodiments of this disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes” and/or “including”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Descriptions are given, with reference to the accompanying drawings, of examples, exemplary embodiments, modification of exemplary embodiments, etc., of an image forming apparatus according to exemplary embodiments of this disclosure. Elements having the same functions and shapes are denoted by the same reference numerals throughout the specification and redundant descriptions are omitted. Elements that do not demand descriptions may be omitted from the drawings as a matter of convenience. Reference numerals of elements extracted from the patent publications are in parentheses so as to be distinguished from those of exemplary embodiments of this disclosure.
This disclosure is applicable to any image forming apparatus, and is implemented in the most effective manner in an electrophotographic image forming apparatus.
In describing preferred embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this disclosure is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes any and all technical equivalents that have the same function, operate in a similar manner, and achieve a similar result.
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, preferred embodiments of this disclosure are described.
Descriptions are given of an example applicable to an image forming apparatus, with reference to the following figures.
It is to be noted that identical parts are given identical reference numerals and redundant descriptions are summarized or omitted accordingly.
Next, a description is given of a series of image forming operations performed by an image forming apparatus 100 according to an embodiment of this disclosure, for forming an image on a sheet.
The image forming apparatus 100 may be a copier, a facsimile machine, a printer, a multifunction peripheral or a multifunction printer (MFP) having at least one of copying, printing, scanning, facsimile, and plotter functions, or the like. According to the present example, the image forming apparatus 100 is an inkjet copier that forms images on recording media by discharging ink.
It is to be noted in the following examples that: the term “image forming apparatus” indicates an apparatus in which an image is formed on a recording medium such as paper, OHP (overhead projector) transparencies, OHP film sheet, thread, fiber, fabric, leather, metal, plastic, glass, wood, and/or ceramic by attracting developer or ink thereto; the term “image formation” indicates an action for providing (i.e., printing) not only an image having meanings such as texts and figures on a recording medium but also an image having no meaning such as patterns on a recording medium; and the term “sheet” is not limited to indicate a paper material but also includes the above-described plastic material (e.g., a OHP sheet), a fabric sheet and so forth, and is used to which the developer or ink is attracted. In addition, the “sheet” is not limited to a flexible sheet but is applicable to a rigid plate-shaped sheet and a relatively thick sheet.
Further, size (dimension), material, shape, and relative positions used to describe each of the components and units are examples, and the scope of this disclosure is not limited thereto unless otherwise specified.
Further, it is to be noted in the following examples that: the term “sheet conveying direction” indicates a direction in which a recording medium travels from an upstream side of a sheet conveying path to a downstream side thereof; the term “width direction” indicates a direction basically perpendicular to the sheet conveying direction.
The sheet P that has been conveyed from the sheet feeding device 10 reaches the sheet conveying device 20. The sheet conveying device 20 includes a pair of sheet gripping rollers 22 to correct the positional deviation of the sheet P. After the positional deviation of the sheet P is corrected by the sheet conveying device 20, the sheet P is conveyed to the image forming device 1 at a predetermined timing.
The image forming device 1 includes a cylindrical drum 3 and sheet grippers 4 mounted on the circumferential surface of the cylindrical drum 3. The sheet grippers 4 grip the leading end of the sheet P when the sheet P is conveyed to the image forming device 1.
After the positional deviation of the sheet P is corrected and the sheet P is conveyed to the image forming device 1, the leading end of the sheet P is gripped by the sheet grippers 4 mounted on the circumferential surface of the cylindrical drum 3, so that the sheet P is positioned on the circumferential surface of the cylindrical drum 3. In addition, the cylindrical drum 3 has multiple air intake holes formed in circumferential surface thereof. By sucking air through the multiple air intake holes from the back side of the sheet P, the whole area of the sheet P is closely attached onto the circumferential surface of the cylindrical drum 3 to hold the sheet P. As the cylindrical drum 3 is rotated in a direction indicated by arrow in
As illustrated in
As illustrated in
The sheet P on which the image is formed by the image forming device 1 is conveyed to a drying device 30. The drying device 30 includes a drying unit 31. The sheet P passes through the lower part of the drying unit 31, so that moisture in ink discharged onto the sheet P is evaporated, and consequently curling of the sheet P is prevented.
The sheet P that has passed through the drying device 30 is conveyed to a sheet output device 40, so that the sheets P are stacked on the sheet output device 40 in an orderly arranged state.
The drying device 30 further includes a sheet direction switching portion 51 and a sheet reversing and conveying member 52. When performing duplex printing, the sheet P is reversed by the sheet direction switching portion 51 and conveyed by the sheet reversing and conveying member 52 toward the image forming device 1. After switching the conveying direction of the sheet P by the sheet direction switching portion 51, the sheet P is conveyed toward the image forming device 1 by the sheet reversing and conveying member 52. The sheet P reaches a sheet conveying device 50 before reaching the cylindrical drum 3. The sheet conveying device 50 functions as a second sheet conveying device. Similar to the sheet conveying device 20, a pair of sheet gripping rollers 53 provided to the sheet conveying device 50 corrects the positional deviation of a sheet while conveying the sheet P. After completion of correction of the positional deviation, the sheet P is conveyed to the cylindrical drum 3, where the sheet P is gripped by one of the sheet gripper 4 and is attached and held onto the circumferential surface of the cylindrical drum 3 with the back face having no image thereon facing up. Then, in the image forming device 1, as described above for forming an image on a front face of the sheet P (i.e., a single-side printing), the head unit 2 forms an image on the back face (with no image formed) of the sheet P that is attached onto the circumferential surface of the cylindrical drum 3.
After passing through the drying device 30, the sheet P has respective images on both sides. Then, similar to the single-side printing, the sheet P is conveyed to the sheet output device 40 and is stacked on the sheet output device 40 in the orderly arranged state.
Next, a description is given of details of the configuration of the sheet conveying device 20 included in the image forming apparatus 100.
Each of the pair of upstream side sheet conveying rollers 21, the pair of sheet gripping rollers 22, and the pair of downstream side sheet conveying rollers 23 includes sheet conveying rollers as a pair of rollers. Each of the pair of upstream side sheet conveying rollers 21, the pair of sheet gripping rollers 22, and the pair of downstream side sheet conveying rollers 23 rotates while gripping the sheet P in a nip region formed between the rollers of the pair, so that the sheet P is conveyed to the downstream side. It is to be noted that the pair of upstream side sheet conveying rollers 21, the pair of sheet gripping rollers 22, and the pair of downstream side sheet conveying rollers 23 are arranged in this order along the sheet conveying direction.
The pair of sheet gripping rollers 22 is rotatable about a pivot point 22a within a plane of sheet conveyance and is movable in the width direction of the sheet P. Through the above-described operations, the pair of sheet gripping rollers 22 rotates the sheet P or moves the sheet P in the width direction while gripping the sheet P, so as to correct the angular displacement of the sheet P or the lateral displacement of the sheet P. It is to be noted that rotations of the pair of sheet gripping rollers 22 are hereinafter distinguished by describing differently. That is, the rotation of the pair of sheet gripping rollers 22 to convey the sheet P is referred to as a “rotation” or a “rotation for sheet conveyance” and the rotation of the pair of sheet gripping rollers 22 to correct the angular displacement of the sheet P is referred to as a “rotation within a plane of sheet conveyance”.
The detecting device 29 includes a first CIS 24 and a second CIS 25, both of which function as detectors. The first CIS 24 and the second CIS 25 are arranged along the sheet conveying direction. Each of the first CIS 24 and the second CIS 25 is a contact image sensor that includes photosensors, each of which including multiple light emitting elements such as LEDs (that is, light emitting diodes) and multiple light receiving elements such as photodiodes. The photosensors including the multiple light emitting elements and the multiple light receiving elements are aligned in the width direction of the sheet P.
Now, a detailed description is given of operations of processes in which the sheet conveying device 20 corrects the positional deviation of the sheet P while conveying the sheet P, with reference to
First, as illustrated in
As the sheet P is further conveyed to the downstream side, the sheet P reaches the second CIS 25, as illustrated in
Referring to
As illustrated in
TAN θ=(Xd1−Xd2)/M Equation 1.
By using Equation 1, the angular displacement amount θ of the sheet P is obtained. It is to be noted that the distance M is a value that is previously measured.
Then, the pair of sheet gripping rollers 22 performs a pick up and operation based on the calculated amounts of lateral and angular displacements of the sheet P (step S4 in the flowchart of
As the sheet P is further conveyed to the downstream side, the sheet P reaches the pair of sheet gripping rollers 22, as illustrated in
The pair of sheet gripping rollers 22 rotates, while gripping the sheet P, to convey the sheet P further to the downstream side. Concurrently with the sheet conveyance, the pair of sheet gripping rollers 22 perform an adjustment operation to correct the positional deviation of the sheet P (step S5 in the flowchart of
As illustrated in
In the present embodiment, at the timing at which the trailing end of the sheet P passes under the first CIS 24 or at a timing earlier than the above timing, the first CIS 24 and the second CIS 25 detect the position of the sheet P (hereinafter, occasionally referred to as a “final detection”), so that the amount of positional deviation pf the sheet P is calculated (step S6 in the flowchart of
As described above, when calculating an amount of angular displacement of the sheet P, detection results of both of the first CIS 24 and the second CIS 25 are used. Therefore, as described above, the position where the trailing end of the sheet P passes under the first CIS 24 is the extreme downstream position at which the sheet P is detected and the amount of angular displacement of the sheet P is calculated. Therefore, by performing the final detection at the above timing and calculating the amount of positional deviation of the sheet P, the amount of positional deviation of the sheet P at a further downstream position is calculated.
In the present embodiment, in order to perform the final detection at a timing at the further downstream position, the first CIS 24 repeatedly detects the sheet P while the sheet P is being conveyed by the pair of sheet gripping rollers 22. Then, the amount of image correction of the sheet P is calculated based on the detection result of the first CIS 24 obtained by detecting the sheet P for the last time and the detection result of the second CIS 25 obtained by detecting the sheet P at the concurrent timing as the first CIS 24. (That is, the detections by the first CIS 24 and the second CIS 25 at this timing corresponds to the above-described final detection.) Accordingly, the amount of image correction of the sheet P is calculated based on a detection results obtained at the timing immediately before the trailing end of the sheet P passes under the first CIS 24. It is to be noted that, in this case, the second CIS 25 functions as an extreme downstream contact image sensor and the first CIS 24 functions as a second extreme downstream contact image sensor.
In the present embodiment, the first CIS 24 detects the sheet P repeatedly. However, the configuration is not limited thereto. For example, this disclosure may be applied to a configuration provided with a sensor to detect the sheet P directly or indirectly at a timing at which the leading end of the sheet P reaches the first CIS 24 and another sensor to detect the sheet P directly or indirectly at a timing at which the trailing end of the sheet P reaches the first CIS 24, and the respective timings at which these sensors detected the sheet P may trigger detection by the first CIS 24 for the pick up operation and the adjustment operation and detection by the first CIS 24 for the final detection.
When the final detection is performed, the pair of sheet gripping rollers 22 terminates the adjustment operation in the middle of the operation but continues sheet conveyance of the sheet P. Then, as illustrated in
In the present embodiment, after the final detection, the correction of positional deviation of the sheet P is not performed until the sheet P is sent to the image forming device 1. In other words, the sheet P is sent to the image forming device 1 with the amount of positional deviation at the final detection.
In the image forming device 1, an image forming operation onto the sheet P is performed, that is, an image is formed on the sheet P. At this time, the image forming operation is performed in a state in which the image forming position at which an image is transferred from the image forming device 1 onto the sheet P is moved from an original image forming position by the amount of image correction of the sheet P (step S8 in the flowchart of
Thus, in the present embodiment, the amount of positional deviation of the sheet P that has not been corrected by the pair of sheet gripping rollers 22 is set to be an amount of image correction of the sheet P. Then, by correcting the image forming position based on the amount of image correction of the sheet P, the image is formed on the correct position on the sheet P having the position deviation.
Now, a detailed description is given of a method of correcting the image forming position.
As illustrated in
As illustrated in
A controller provided to the image forming apparatus 100 reads image information input to the image forming apparatus 100 and generates image data of an image to be formed on the sheet P. For example,
Then, based on the above-described image data, ink discharge data is generated to determine which of the multiple ink discharging nozzles 57 discharge ink at what timing. The rows of the ink discharging nozzles 57 illustrated in
In a case in which the sheet P has a positional deviation when forming an image to the sheet P, the image to be formed on the sheet P has a positional deviation by the same amount of positional deviation of the sheet P. For example, as illustrated in
With respect to the positional deviation of the image, in the present embodiment, the image forming position is corrected by the above-described amount of image correction of the sheet P. By so doing, the image position of the image to be formed on the sheet P is corrected. There are two specific methods of correcting an image position, which are a method of changing ink discharge data of the ink discharging nozzles 57 and a method of changing the image data.
Next, as an example of methods of correcting the image position, a description is given of a method of correcting an image position when the sheet P has a positional deviation in the width direction of the sheet P (in a case of
In a case in which ink discharge data is changed, as illustrated in
When changing the image data, as illustrated in
According to the above-described changes, as illustrated in
As described above, in the present embodiment, even when the positional deviation of the sheet P is not completely corrected by the pair of sheet gripping rollers 22, the image is formed without generating the positional deviation of the sheet P by correcting the image forming position of the sheet P. Accordingly, even in an image forming apparatus such as a commercial printing machine in which high image quality and high productivity are required, the image forming position of the sheet P is corrected without degrading productivity.
It is to be noted that, in the above description, the image forming position is corrected in the width direction of the sheet P. However, the image forming position may be corrected in the rotation direction within a plane of sheet conveyance of the sheet P. In this case, however, the correction of the positional deviation of the sheet P is achieved by the method of changing image data, not by the method of changing ink discharge data. That is, since the ink discharge data is changed by shifting the ink discharge data generated based on the image data in the width direction of the sheet P, the correction is performed to the positional deviation of the sheet P in the width direction (i.e., the lateral deviation of the sheet P), not to the positional deviation of the sheet P in the rotation direction (i.e., the angular deviation of the sheet P). By contrast, as illustrated in
As illustrated in
The sheet position recognition unit 61 calculates the angular displacement amount of the sheet P and the lateral displacement amount of the sheet P based on detection information received from the first CIS 24 and the second CIS 25. Then, the sheet position recognition unit 61 sends information of the angular and lateral displacement amounts of the sheet P to the first motor control unit 62 and the second motor control unit 63. The sheet position recognition unit 61 calculates the amount of image correction of the sheet P based on the detection results of the first CIS 24 and the second CIS 25 in the final detection. Then, the information of the amount of image correction of the sheet P is transmitted to the formed image control unit 64.
The first motor control unit 62 and the second motor control unit 63 control each movement of the pair of sheet gripping rollers 22 and determine the amount of movement of the pair of sheet gripping rollers 22 based on the information of the angular and lateral displacement amounts of the sheet P sent from the sheet position recognition unit 61.
Specifically, the first motor control unit 62 controls rotation of the pair of sheet gripping rollers 22 within a plane of sheet conveyance. A first motor driver 621 drives a first motor 622 according to a signal sent from the first motor control unit 62 to rotate the pair of sheet gripping rollers 22 within a plane of sheet conveyance. Then, a first motor encoder 623 detects the amount of rotations of the pair of sheet gripping rollers 22 within the plane of sheet conveyance.
The second motor control unit 63 controls movement of the pair of sheet gripping rollers 22 in the width direction. A second motor driver 631 drives a second motor 632 according to a signal sent from the second motor control unit 63 to move the pair of sheet gripping rollers 22 in the width direction. Then, a second motor encoder 633 detects the amount of movement of the pair of sheet gripping rollers 22 in the width direction.
The formed image control unit 64 creates image data and ink discharge data and transmits the ink discharge data to the image forming device 1. Based on the ink discharge data transmitted from the formed image control unit 64, the image forming device 1 discharges ink of each color from the ink discharging nozzles 57 to form an image on the sheet P. In addition, in a case in which information of the amount of image correction of the sheet P is received from the sheet position recognition unit 61, the image forming device 1 changes the image data and the ink discharge data based on the information of the amount of image correction of the sheet P. By so doing, the image forming position is corrected.
Now, a description is given of the sheet conveying device 20 that has a detecting device 29A having a different configuration from the configuration of the detecting device 29, with reference to
The sheet conveying device 20 of
As illustrated in
Then, as illustrated in
The detection of the position of the sheet by the second CIS 25 and the third CIS 26 and the recorrection by the pair of sheet gripping rollers 22 based on the detection results of the second CIS 25 and the third CIS 26 are performed repeatedly until the trailing end of the sheet P arrives the second CIS 25, in other words, until the second CIS 25 detects the sheet P for the last time, i.e., a final detection by the second CIS 25 (steps S17 through 19 in the flowchart of
In the present embodiment, the timing at which the trailing end of the sheet P passes under the second CIS 25, as illustrated in
In the configuration of the sheet conveying device 20 of
The pair of sheet gripping rollers 22 moves quicker in the rotation direction within a plane of sheet conveyance when compared with movement in the width direction. Therefore, according to the configuration of a sheet conveying device, it is likely that the detected angular displacement of the sheet P is sufficiently corrected by the correction operation (i.e., the adjustment operation and the recorrection operation) performed by the pair of sheet gripping rollers 22. In this case, the image forming position is corrected for the positional deviation of the sheet P in the width direction but is not corrected in the rotation direction within a plane of sheet conveyance. According to this configuration, the final detection of the sheet P is performed by the pair of sheet gripping rollers 22 at a further downstream position in the sheet conveying direction, and therefore the correction operation performed by the pair of sheet gripping rollers 22 continues to a further downstream side of the sheet conveying direction.
Specifically, when the image forming position of the sheet P is corrected in the width direction alone, in other words, when the amount of positional deviation is corrected in the width direction of the sheet P alone in the final detection, it is sufficient to provide a single CIS for detecting the sheet P. Therefore, for example, as illustrated in
It is to be noted that, in a case in which the timing at which the sheet P reaches the pair of downstream side sheet conveying rollers 23, in other words, the timing at which the pair of sheet gripping rollers 22 completes sheet conveyance of the sheet P and separates from the sheet P, is earlier than the timing at which the trailing end of the sheet P passes under the second CIS 25, the timing of the final detection may be set to a timing at which the sheet P reaches the pair of downstream side sheet conveying rollers 23. Alternatively, contrary to the above-described configuration, the pair of sheet gripping rollers 22 may correct the image forming position of the sheet P in the width direction (i.e., the lateral displacement of the sheet P) without correcting the image forming position of the sheet P in the rotation direction within a plane of sheet conveyance (i.e., the angular displacement of the sheet P).
As illustrated in
The photographing range of the camera 27 is set, for example, from a position immediately downstream from the pair of upstream side sheet conveying rollers 21 to a position immediately upstream from the pair of downstream side sheet conveying rollers 23. The camera 27 is disposed such that an imaging surface of the camera 27 is parallel to the surface of the sheet P being conveyed in the sheet conveyance passage.
When the sheet P is conveyed in the sheet conveying device 20 (i.e., the sheet conveying device 20 of
In the configuration of the sheet conveying device 20 including the detecting device 29B, as long as the sheet P moves within the photographing range of the camera 27, the amount of angular displacement of the sheet P (i.e., the amount of positional deviation of the sheet P in the rotation direction within a plane of sheet conveyance) is calculated. Therefore, the possible range for calculating the amount of angular displacement of the sheet P is provided on the further downstream side of the sheet conveying direction. Accordingly, the amount of positional deviation of the sheet P calculated at a position on the further downstream side corresponds to the amount of image correction of the sheet P and the correction operation performed by pair of sheet gripping rollers 22 is continued to the further downstream side.
It is to be noted that the sheet conveying device 50 (see
The above-described embodiments are illustrative and do not limit this disclosure. It is therefore to be understood that within the scope of the appended claims, numerous additional modifications and variations are possible to this disclosure otherwise than as specifically described herein.
In addition, the “sheet” includes the sheet P (plain papers), thick papers, postcards, envelopes, thin papers, coated papers (coated papers, art papers, etc.), tracing papers, OHP sheets, plastic films, prepreg, copper foil, etc.
The above-described embodiments are illustrative and do not limit this disclosure. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements at least one of features of different illustrative and exemplary embodiments herein may be combined with each other at least one of substituted for each other within the scope of this disclosure and appended claims. Further, features of components of the embodiments, such as the number, the position, and the shape are not limited the embodiments and thus may be preferably set. It is therefore to be understood that within the scope of the appended claims, the disclosure of this disclosure may be practiced otherwise than as specifically described herein.
Each of the functions of the described embodiments may be implemented by one or more processing circuits or circuitry. Processing circuitry includes a programmed processor, as a processor includes circuitry. A processing circuit also includes devices such as an application specific integrated circuit (ASIC), digital signal processor (DSP), field programmable gate array (FPGA), and conventional circuit components arranged to perform the recited functions.
Number | Date | Country | Kind |
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JP2018-020986 | Feb 2018 | JP | national |
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20070145667 | Pasuch | Jun 2007 | A1 |
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