JP6187136B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  The belt-like continuous paper used for image formation includes continuous paper in which feed holes are provided at regular intervals in the paper length direction and continuous paper (pinless paper) in which no feed holes are provided.

  For example, in Patent Document 1, continuous paper having a feed hole is sandwiched between platens, and a tractor stabbed on the downstream side in the paper feed direction is hooked on the platen to the feed hole, and the rotation of the tractor and the rotation of the platen are linked Thus, a continuous paper printer that feeds continuous paper in the longitudinal direction is disclosed.

  Further, for example, Patent Document 2 employs a friction conveyance method as a continuous paper conveyance method, and image formation in which a detection sensor is provided as a feed hole detection unit that detects feed holes provided at a constant interval in the continuous paper. An apparatus is disclosed.

JP-A-11-314421 JP 2009-298013 A

  An object of the present invention is to reduce waste of a recording material.

An image forming apparatus according to claim 1 is provided.
A transport path for transporting a continuous recording material in a strip shape;
An image forming device that forms a series of images that are allowed to be one image on the recording material in the middle of the conveyance path;
A detector for detecting the feed hole on the upstream side of the transport path from the image forming device when the recording material is provided with a feed hole;
With respect to another image area existing downstream of the conveyance path with respect to the image area corresponding to the feed hole detected by the detector, the series of the image forming apparatus at the time corresponding to the detection time of the feed hole. A formation control unit that starts forming the top of the image of
It is provided with.

An image forming apparatus according to claim 2
The recording material has a plurality of folds extending in the direction intersecting the transport direction,
The forming time control unit sets the head of the series of images to the image forming device when a fold existing downstream of the conveying path reaches the image forming device when the feeding hole is detected. It is characterized by starting formation.

  According to the image forming apparatus of the first aspect, it is possible to reduce the waste of the recording material as compared with the case where the formation time control unit having this configuration is not provided.

  According to the image forming apparatus of the second aspect, it is possible to avoid the image formation overlapping the crease.

1 is a schematic diagram illustrating a configuration of a printer corresponding to an embodiment of an image forming apparatus of the present invention. 6 is a flowchart showing image formation control processing. It is a timing chart showing the timing of exposure and continuous paper conveyance. FIG. 6 is a diagram illustrating image formation on a portion located downstream of the feed hole detected for the first time in the continuous paper conveyance. It is explanatory drawing which shows the calculation procedure of a subscanning correction value. It is a figure showing the state at the time of the initial detection of a feed hole of the subscanning correction value stored in the buffer. It is a figure showing the state when the feed hole after the 2nd page of the subscanning correction value stored in the buffer is detected.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram showing a configuration of a printer corresponding to an embodiment of an image forming apparatus of the present invention.

  The printer 100 is an electrophotographic image forming apparatus, and includes a photosensitive drum 31 whose surface is sensitive to light, a charger 32 that charges the surface of the photosensitive drum 31 to a predetermined potential, and a photosensitive drum 31. An exposure unit 33 that forms an electrostatic latent image on the surface of the photosensitive drum 31 by exposing the surface based on image data is provided. The exposure device 33 is an LED array in which a number of LEDs as light sources are arranged. Further, the printer 100 includes a developing unit 34 that develops the electrostatic latent image formed on the surface of the photosensitive drum 31 with toner, and a transfer roll that transfers the toner image formed on the surface of the photosensitive drum 31 to the continuous paper P. 35, a cleaner 36 for removing residual toner on the surface of the photosensitive drum 31, and a flash fixing device 41 for flash fixing the toner image on the continuous paper P.

  In addition, the printer 100 includes a carry-in roll 21 that carries a continuous strip of continuous paper P into the printer 100, a drive roll 22 that is rotated by a drive motor (not shown), and a continuous roll carried into the transfer roll 35. A tension applying member 23 that applies tension to the paper sheet P, and conveying belt members 25 and 26 that are arranged on the upstream side and the downstream side of the transfer roll 35 and carry the continuous paper sheet P into and out of the transfer roll 35, respectively. I have. The printer 100 also includes a tension applying roll member 42 that applies tension to the continuous paper P. Further, the printer 100 includes a continuous paper stacking member 44 that folds the continuous paper P and swings it to the storage container 45 by swinging left and right. The continuous paper P used in the printer 100 includes a type in which a plurality of feed holes are formed along the edge of the belt and a type in which no feed holes are provided. In the following description, it is assumed that the continuous paper P having the type Further, the continuous paper P is folded at regular intervals, and the continuous paper stacking member 44 folds the continuous paper P at this fold. The section of the continuous paper P divided by folds is a page, and image formation on the continuous paper P is executed so that the images do not overlap with each other across the pages. There are 3.5 inches (about 8.75 cm), 7.0 inches (about 17.5 cm), 11 inches (about 27.5 cm), etc., and the page size is selected by the user. The continuous paper P having the specified page size is used.

  The printer 100 includes a printer control unit 50 that controls the entire operation. In addition, the printer 100 includes a detection sensor 37 that detects a feed hole of the continuous paper P at a position along the conveyance path of the continuous paper P and upstream of the transfer roll 35. As the detection sensor 37, for example, a transmissive photoelectric sensor is used.

  In the printer 100 of the present embodiment, image data is input to the printer control unit 50 when an image forming operation is started. The printer control unit 50 performs various types of image processing on the input image data and outputs the processed image data to the exposure unit 33.

  In addition, the printer control unit 50 starts control of the sheet conveyance operation in response to the input of the image data, and applies the continuous paper P at a predetermined conveyance speed while applying tension to the continuous paper P. Transport.

  The printer 100 forms a toner image under the control of the printer control unit 50. That is, the photosensitive drum 31 starts rotating, the surface of the photosensitive drum 31 is charged to a predetermined potential (for example, −500 V) by the charger 32, and the electrostatic latent image corresponding to the image data by the exposure device 33. Is formed. Then, the electrostatic latent image on the photosensitive drum 31 is developed with toner by the developing unit 34 to form a toner image. The toner image formed on the surface of the photosensitive drum 31 is transferred onto the continuous paper P by the transfer roll 35. Thereafter, the continuous paper P on which the toner image is formed is carried into the flash fixing device 41, and the toner image is fixed on the continuous paper P.

  The continuous paper P corresponds to an example of the recording material according to the present invention, and the path from the carry-in roll 21 to which the continuous paper P is transported to the storage container 45 corresponds to an example of the transport path according to the present invention. The combination of the photosensitive drum 31, the charger 32, the exposure device 33, the developing device 34, and the transfer roll 35 corresponds to an example of the image forming device referred to in the present invention. Therefore, in the following description, the transfer of the image onto the continuous paper P by the transfer roll 35 may be referred to as “image formation on the continuous paper P”. The detection sensor 37 corresponds to an example of a detector according to the present invention, and the printer control unit 50 also functions to correspond to an example of a formation time control unit according to the present invention, as will be described later.

  In the printer 100 using the continuous paper P as a recording material, the timing for forming (i.e., transferring) an image on the continuous paper P is adjusted to the timing in accordance with the transport timing of the continuous paper P. In order to adjust the transfer timing in this way, specifically, the writing timing at which an image is written on the surface of the photosensitive drum 31 by exposure by the exposure device 33 is adjusted. The printer 100 needs to be loaded with the continuous paper P prior to the start of image formation, and the continuous paper P is passed through the entire conveyance path from the carry-in roll 21 to the storage container 45 described above. Then, image formation is started. The page size of the continuous paper P is given in advance to the printer control unit 50 by an input operation or the like by the user when the continuous paper P is loaded in the printer 100. Since the position of the fold of the continuous paper P is specified when the continuous paper P is loaded prior to the start of image formation, the position of the fold is confirmed when the position of the feed hole is detected.

  FIG. 2 is a flowchart showing image formation control processing.

  The control process represented by this flowchart is a process executed by the printer control unit 50 and is started when image data is input to the printer control unit 50.

  When the control process is started, first, in step S101, it is determined whether or not a feed hole is detected by the detection sensor 37. When the feed hole is detected (step S101; Y), the process proceeds to step S102, and it is determined whether or not the feed hole detection is the first time. Here, “first time” means the first time after the continuous paper P is newly loaded in the printer 100. If the detection of the feed hole is the first detection (step S102; Y), the “number of pre-printable sheets” is calculated in step S104, and the exposure start timing is calculated and set in step S105.

The position of the detection sensor 37 for detecting the feed hole is about 15 inches (about about 15 inches from the transfer position where the image is transferred onto the continuous paper P by the transfer roll 35 in relation to other components whose arrangement is prioritized. About 37.5 cm) is located upstream of the continuous paper P conveyance. The portion of the continuous paper P existing on the upstream side of the continuous paper P conveyance further than the position of the continuous paper P whose position is confirmed by the first detection of the feed hole is sent by the detection sensor along with the conveyance. By detecting the holes sequentially, the leading position of each page is sequentially confirmed, and the exposure device 33 is configured so that the image is transferred at the timing when the confirmed position reaches the position of the transfer roll 35. Image export is executed. On the other hand, for the portion of the continuous paper P existing downstream of the continuous paper P transported from the location of the continuous paper P whose position has been confirmed by the initial detection of the feed hole, an image obtained by such position confirmation is used. However, it is wasteful to leave the continuous paper P of about 15 inches (about 37.5 cm) from the transfer position to the position of the detection sensor 37 as blank paper as it is. Therefore, in the printer 100 of the present embodiment, in step S104, the number of pages existing in the section from the position of the detection sensor 37 to the transfer position is calculated based on the position confirmed by the initial detection of the feed hole. In step S105, the exposure start timing for forming an image for the portion of the continuous paper P corresponding to the number of pages is calculated and set. The calculation formula at this time is
{(Distance from the position of the detection sensor 37 to the transfer position)
-(Distance of the surface of the photosensitive drum 31 from the exposure device 33 to the transfer roll 35)
− (Distance from the top of the page to the first detection position of the feed hole)} ÷ page size. The quotient (integer part) of this calculation formula is the number of pages obtained in step S104, and the value obtained by dividing the remainder of this calculation formula by the process speed is the timing obtained in step S105.

  When the exposure start timing is set in this way, the process waits until the start timing is reached (step S106), and exposure by the exposure unit 33 is started (step S107).

  Here, the description of the flowchart of FIG. 2 is temporarily interrupted, and the results generated by the timing adjustment in steps S104 to S107 will be described below using a timing chart or the like.

  FIG. 3 is a timing chart showing the timing of exposure and continuous paper transport.

  The part (A) in FIG. 3 shows the timing of the detection signal output from the detection sensor 37, and part (B) shows the timing of exposure (ie, image drawing) by the exposure device 33. C) shows the timing of image transfer by the transfer roll 35.

  Also, part (D) in FIG. 3 shows the acceleration / deceleration timing in the conveyance of the continuous paper P, and part (E) shows an image (printing result) formed on the continuous paper P. (Including some cases).

  The pulse 51 of the detection signal shown in Part (A) corresponds to the initial detection of the feed hole. In FIG. 3, the detection signals of the subsequent feed holes are not shown.

  As shown in Part (D), the continuous paper P is initially stopped, and then reaches a constant process speed and stabilizes while accelerating from there for 4 inches (about 10 cm). . After reaching a stable process speed in this way, detection of the feed hole is started.

  The exposure start timing shown in part (B) is slightly delayed from the pulse 51 in part (A). This delay corresponds to the exposure start timing calculated in step S105 of FIG. 2 and waited in step S106. The transfer timing shown in part (C) is slightly delayed from the exposure timing of part (B). This delay is caused by the movement time during which the surface of the photosensitive drum 31 rotates from the exposure position at which the surface of the photosensitive drum 31 is exposed by the exposure device 33 shown in FIG. 1 to the transfer position at which the toner image is transferred by the transfer roll 35. Equivalent to.

  As shown in Part (E), image formation is started on the continuous paper after the continuous paper is conveyed to some extent with blank paper. As will be described in detail later, this image formation is started before the first detection feed hole reaches the transfer position.

  When a series of images to be formed on the continuous paper (a series of images represented by the image data input to the printer control unit 50 shown in FIG. 1) are all formed on the continuous paper (that is, image transfer), As shown in Part (D) of FIG. 3, deceleration is executed while the continuous paper is being conveyed by one inch (about 2.5 cm), and the continuous paper is stopped. Then, the continuous paper is transported 5 inches (about 12.5 cm) in the direction opposite to the transport direction during image formation and stopped. As a result, the continuous paper is in a state where the position where the image formation has been completed is pulled back 4 inches (about 10 cm) upstream of the conveyance. When new image data is input to the printer control unit 50 shown in FIG. 1 and image formation is restarted, the process speed is being transferred while the pulled back continuous paper for 4 inches (about 10 cm) is being conveyed. Therefore, the next image formation is started immediately after the portion where the image formation has been completed in the previous image formation processing. As a result, as long as the continuous paper is not replaced, no waste paper is generated between the image forming process and the image forming process.

  FIG. 4 is a diagram showing image formation on a portion located downstream of the feed hole detected for the first time in the continuous paper conveyance.

  The left side of FIG. 4 is the upstream side of the continuous paper transport, and the right side is the downstream side. A transfer position 52 is indicated by a dotted line at the right end of FIG. Further, a feed hole 53 indicated by shading on the left side of FIG. 4 represents a feed hole detected for the first time.

  FIG. 4 shows an example of image formation corresponding to each of three types of page sizes (that is, print lengths), and a fold line 54 corresponding to each page size is shown.

  An example of a page size of 3.5 inches (approx. 8.75 cm) is shown in part (A) of FIG. 4, and an example of a page size of 7.0 inches (approx. 17.5 cm) is shown in part (B). An example of a page size of 11 inches (about 27.5 cm) is shown in Part (C).

  When the page size is 3.5 inches, as shown in Part (A), an image for three pages is formed between the first detection feed hole 53 and the transfer position 52. This page number “3” is equal to the page number calculated in step S104 of FIG. In both cases where the page size is 7.0 inches and the page size is 11 inches, as shown in Part (B) and Part (C), the number of pages on which an image is formed is one page. Since the page size is larger, the example shown in Part (C) has fewer blank pages. Whatever page size of continuous paper is used, the portion that becomes a blank page is less than one page, and the timing until the fold line 54 reaches the transfer position 52 after the blank sheet of less than one page is conveyed. Corresponds to the exposure start timing calculated in step S105 of FIG. Since the start timing of image formation is matched with the arrival of the fold, image formation overlapping the fold 54 of the page is avoided.

  Further, by adopting a page size shorter than a section of about 15 inches (about 37.5 cm) from the transfer position to the position of the detection sensor 37, at least on the downstream side in the transport direction from the feed hole 53 of the first detection. Image formation for one page is performed, and generation of waste paper is suppressed.

  The above-described timing adjustment operation in steps S104 to S107 of FIG. 2 corresponds to an example of the operation as the formation control unit referred to in the present invention.

  Hereinafter, the description returns to the interrupted flowchart of FIG.

  When the feed hole is detected (step S101; Y) and the detection is the second or later detection (step S102; N), the process proceeds to step S103, and the sub-scan correction value is determined based on the feed hole detection timing. Is calculated. Here, the sub-scan correction is to correct the exposure position in the rotation direction of the photosensitive drum (that is, the sub-scan direction), and the correction of the position is realized by correcting the exposure timing. Accordingly, the sub-scan correction value calculated in step S103 is an exposure timing correction value.

  FIG. 5 is an explanatory diagram showing a sub-scan correction value calculation procedure.

  FIG. 5 conceptually shows the continuous paper P and the feed holes 55_1, 55_2, and 55_3 provided in the continuous paper P, and the passage of time and the feed holes of the continuous paper P are conveyed. The detection timings 55_1, 55_2, and 55_3 are also shown, and time passes from the left to the right in the figure.

  From the start time point at which the first feed hole 55_1 is detected, the printer control unit 50 generates a reference pulse 56 serving as a reference for sub-scanning correction at every fixed reference timing. The reference timing at which the reference pulse 56 is generated corresponds to the transport time required for transporting the continuous paper P for one page at the set process speed, and the reference generated at each reference timing. If the detection of the feed hole with respect to the pulse 56 is the same timing, the continuous paper P is properly conveyed at the set process speed. For example, the detection of the feed hole 55_2 on the second page shown in FIG. 5 has the same timing as the reference pulse 56, and the sub-scan correction value at this time is “0”. For example, the detection of the feed hole 55_3 on the third page is delayed with respect to the reference pulse 56, so the sub-scan correction value becomes a positive value that delays the exposure timing, and the correction amount is the detection of the feed hole 55_3 and the reference pulse 56. Is equal to the timing difference.

  The sub-scan correction value calculated in this way is stored in a buffer provided in the printer control unit 50, and is reflected in the timing at which image data is output from the printer control unit 50 to the exposure device 33.

  6 and 7 are diagrams showing the sub-scan correction values stored in the buffer. FIG. 6 shows the state when the feed holes are detected for the first time, and FIG. 7 shows the feed holes for the second and subsequent pages. The state when it was detected is shown.

  The buffer 60 stores correction values in order from the upper level to the lower level each time a feed hole is detected. When the feed hole is detected for the first time, “0” is stored as the correction value as shown in FIG. 6, and further, it corresponds to the page preceding the feed hole for the first detection (that is, existing on the downstream side of the continuous paper transport). The correction value also stores “0”. Then, when detecting the feed holes for the second and subsequent pages, the correction value calculated as described with reference to FIG. Then, the correction values stored in such a manner are read in order from the upper stage to the lower stage in the figure, and the output timing of the image data becomes the timing obtained by adding the correction value to the reference timing described above.

  Image formation is continued while such a sub-scan correction value is calculated in step S103 of FIG.

  In the control process shown in FIG. 2, when the feed hole is not detected (step S101; N), it is confirmed whether or not the exposure end timing of each page has come (step S108), which is the page exposure end timing. In this case, it is confirmed whether or not an instruction to stop printing is received by the printer control unit 50 (step S109). When each page is being exposed (step S108; N) or when no print stop instruction has been received (step S109; N), image formation is continued and a print stop instruction is received (step S109). ; Y), the process proceeds to step S110, the stop process including the reverse conveyance described with reference to FIG. 3 is executed, and the image forming process and the control process are completed.

  In the above description, an electrophotographic system is shown as an example of the image forming apparatus according to the present invention. However, the image forming apparatus according to the present invention may be of another system such as an ink jet system.

  In the above description, a feed hole detection sensor is provided, and the fold line separating the pages is indirectly confirmed by detecting the feed hole. However, the image forming apparatus of the present invention directly detects the fold line. A sensor for detecting may be provided.

DESCRIPTION OF SYMBOLS 100 Printer 21 Carry-in roll 22 Drive roll 25,26 Conveying belt member 31 Photosensitive drum 32 Charging device 33 Exposure device 34 Developing device 35 Transfer roll 37 Detection sensor 41 Flash fixing device 50 Printer control part

Claims (2)

A transport path for transporting a continuous recording material in a strip shape;
An image forming device that forms a series of images that are allowed to be one image on the recording material in the middle of the conveyance path;
When the recording material is provided with a feed hole, a detector that detects the feed hole on the upstream side of the conveyance path from the image forming device;
With respect to another image area existing on the downstream side of the conveyance path with respect to the image area corresponding to the feed hole detected by the detector, the series of the image forming apparatus at the time corresponding to the detection time of the feed hole. A formation control unit that starts forming the top of the image of
An image forming apparatus comprising: The recording material has a plurality of folds extending in a direction intersecting the transport direction,
When the formation control unit detects the feed hole, a crease existing on the downstream side of the transport path from the feed hole reaches the image forming unit. The image forming apparatus according to claim 1, wherein the image forming apparatus starts forming the image.

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