JP2005195866A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize collation even on preprinting paper or the like in collating output in order to guarantee an output object. <P>SOLUTION: A method with which the output first copy is read and collated with the second and succeeding copies is realized other than the ordinary collation with original data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as a printer, a copying machine, a facsimile machine, and a multifunction machine. In particular, the present invention relates to an image forming apparatus that performs collation.

  In the image forming apparatus, the possibility that an abnormality occurs in the image-formed sheet is not zero. For example, there are image abnormalities such as image smudges and image omissions, and sheet abnormalities such as sheet skew, folding and scratches. Conventionally, in order to guarantee this, a sheet on which an image has been formed is read, and the read image is checked against the original image data for any abnormality. The reading unit scans the sheet at a constant part or cycle, and reads the image on the sheet and the shape / posture of the sheet such as skew, folds, and scratches of the sheet. The resolution to be read is determined by the sheet conveyance speed and the scanning period of the reading means. Assuming that the conveyance speed is Vps (m / s) and the scanning period Tr (s) of the reading means, the resolution is Vps / Tr.

Conventionally, collation for guaranteeing an image-formed sheet is mainly collation when printing a large amount of banknotes or specific images, and the collation method has one method (for example, (See Patent Document 1).
Japanese Patent Publication No. 04-020231

  However, in recent years, there has been a strong demand for image formation on paper such as pre-printed sheets and tabbed sheets in small lots in addition to outputting images on ordinary sheets. Since the output image of the means is different from the original data, it cannot be simply compared with the original data.

  The present invention has been made in view of the above points, and reads a first image of an output and uses the data for comparison of the second and subsequent images, so that a pre-printed sheet or a tabbed sheet is obtained. It is possible to collate even when outputting to paper, etc., and to detect abnormalities accurately.

  In addition, it is possible to collate with the original data, both can be selected, and the priority collation order can be set according to the mode, so that collation can be appropriately performed according to the needs, modes and sheet conditions at that time It can be done. Furthermore, it is possible to perform appropriate collation (not excessive or sweet) by changing the matching judgment level between the original data and the first image. .

  As described above, if the present invention is organized and summarized, it can be integrated into the following configurations.

(1) In an image forming apparatus that forms image data on a sheet,
Reading means for reading the image or shape / posture of the image-formed sheet;
Collation data holding means having data to be collated with the read data read by the reading means;
Collating means for performing the collating operation;
A judgment means for judging whether or not a set threshold value is exceeded as a result of the matching,
An image forming apparatus characterized in that there are a plurality of collation data acquisition destinations of data to be collated entering the collation data holding means.

  (2) The image forming apparatus according to (1), wherein at least one of the plurality of collation data acquisition destinations is the reading unit.

  (3) The image forming apparatus according to (1), wherein two of the plurality of collation data acquisition destinations are the reading unit and the image data.

  (4) The image forming apparatus according to (1), wherein a threshold value set in the determination unit is different depending on where the collation data is obtained.

  (5) The image forming apparatus according to (3), wherein the threshold value set in the determination unit is lower in the image data between the reading unit from which the collation data is obtained and the image data.

  (6) The image forming apparatus according to (1), wherein which one of the plurality of collation data acquisition destinations is selected is determined by the collation data holding unit by judging a job mode and a sheet type. apparatus.

  (7) The image forming apparatus according to (3), wherein among the plurality of collation data acquisition destinations, the first part is the image data, and the second and subsequent parts are the reading unit.

  (8) The image forming apparatus according to (7), wherein the sheet conveying speed is lower than normal when the first unit reads the first portion.

  According to the present invention, by reading the first image of the output and using the data for comparison of the second and subsequent images, it is possible to collate even when outputting to a paper such as a pre-printed sheet or a tabbed sheet. Can be found accurately. In addition, it is possible to collate with the original data, both can be selected, and the priority collation order can be set according to the mode, so that collation can be appropriately performed according to the needs, modes and sheet conditions at that time It can be done. Furthermore, it is possible to perform appropriate collation (not excessive or sweet) by changing the matching judgment level between the original data and the first image. .

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

  FIG. 1 is a schematic configuration diagram of a digital composite copying machine as an example of an image forming apparatus according to an embodiment of the present invention. Reference numeral 1 denotes a digital composite copying machine main body, and an original platen 2 having a transparent glass plate fixedly provided is provided on the upper portion of the main body 1. Reference numeral 3 denotes a document feeding device that conveys a sheet-like document to a predetermined position on the document table 2. The document conveyed to the document table 2 by the document feeding device 3 is read by the reading unit 4 and read. The data is processed by the image processing unit, converted into an electrical signal, and transmitted to the writing laser unit 5.

  Here, the digital composite copying machine main body 1 functions as a copying machine when data from the reading unit 4 is input to the writing laser unit 5, and functions as a printer when an output signal of a personal computer is input. Further, if a transmission signal from the facsimile machine of another machine is input and a signal from the reading unit 4 is transmitted to the facsimile machine of the other machine, it functions as a facsimile machine. Based on these input data, the writing laser unit 5 emits laser light and scans the photosensitive drum 12.

  Reference numeral 1A denotes a sheet feeding unit. The sheet feeding unit 1A supplies sheets S accommodated in decks 30, 31, 32, and 33, which are sheet storage units built in the digital multifunction copying machine main body 1, to the image forming unit 1B. A multi-sheet feeding unit 210 that is a manual sheet feeding device including a deck sheet feeding unit 34, 35, 36, and 37 for feeding sheets, a multi-sheet feeding tray 74 that is a sheet stacking unit, and a sheet feeding unit 210A is provided. .

  The image forming unit 1B includes an electrophotographic photosensitive drum 12, a charger 13, a developing device 14, a transfer charger 19, and the like. Then, a laser beam corresponding to the image information emitted from the writing laser unit 5 is scanned on the surface of the photosensitive drum 12 uniformly charged by the charger 13 to form a latent image, and a developing device is formed on the latent image. A toner image is formed by 14, and the toner image is transferred to the upper surface of the sheet S by the transfer charger 19 on the sheet S conveyed in synchronization with the rotation of the photosensitive drum 12. Further, a separation charger 20 for separating the transferred sheet and a cleaner 26 for removing the toner remaining on the drum 12 are also provided.

  Further, downstream of the image forming unit 1B, a conveyance unit 21 that conveys the sheet S to which the toner image is transferred, and a fixing device 22 that fixes the image on the sheet S conveyed by the conveyance unit 21 are provided. ing. Further, a discharge roller 24 that discharges the sheet from the main body 1 is provided on the downstream side of the fixing device 22. The sheet S on which the toner image is formed is conveyed to the fixing device 22 and is heated and pressed to fix the toner image on the surface of the sheet S. The sheet S that has been fixed is discharged by a discharge roller 24 to a discharge tray 25 or a post-processing device 26 (not shown). On the downstream side of the discharge roller 24, reading means 1001 and 1002 are provided for reading the image of the sheet on which the image has been formed or the shape / posture. Reading means 1001 and 1002 are contact image sensors (CIS) incorporating an image sensor and a light source for illumination. The reading means is not limited to the contact image sensor. The sheet is discharged by the discharge roller 24 in the following three patterns. [1] The image surface is discharged at the top. [2] The image surface is discharged below. [3] The image surface is discharged on both upper and lower sides. In the case of [2], the sheet is reversed and discharged by the both-side reversing / both-side conveying path 121 and the reversing large roller 115. In the case of [3], the sheet is reversed by the double-side reversal / double-side conveyance path 121, the large reverse roller 115, the conveyance rollers 112 to 114, and re-conveyed to the image forming unit 1B to record the second surface. , Fixed and discharged. By providing the reading means 1001 and 1002 on both the upper and lower sides, it is possible to read the image or the shape / posture of the sheet discharged in these three patterns.

  The reading units 1001 and 1002 scan the sheet discharged by the discharge roller 24 at a constant cycle, and read the image on the sheet and the shape / posture of the sheet such as skew, bending, and scratches. Further, the data read by the reading means 1001 and 1002 is collated with the image data of the collation source for any abnormality.

  Further, upstream of the reading units 1001 and 1002, units 105, 106, 116, 117, 118, 119, 120 for detecting sheets are provided in each unit. These sensors detect the behavior of the sheet being conveyed.

  A control unit 130 controls the operation of the image forming apparatus 1 and determines the actual operation, status, and sheet state of the apparatus.

  For example, between sheets of conveyed sheets, sheet overlap feed (multifeed), retry operation during separation, whether or not the sheet feeding means is changed during image formation, remaining amount of toner, motor rotation, power, roller system Rotation unevenness, number of transported sheets, timing of various operations, and the like.

  Normally, each of these events is controlled with some allowance. If the margin adversely affects image formation or does not operate normally, the apparatus is stopped (jammed). If the margin is within the margin, the apparatus continues to operate.

  A method for collating the data read by the reading units 1001 and 1002 with the image data of the collation source will be described in detail.

  First, there are three patterns as a verification method.

  The first pattern is compared with the original electronic data used for irradiation by the writing laser unit 5. This is used when the sheet on which the image is formed is a normal sheet such as white, and when it is below the matching determination level α for collation, it is determined that there is an abnormality (the flowchart is FIG. 2).

  The second pattern is for comparing the second and subsequent copies using the data read by the reading means 1001 and 1002 as the first pattern as the image data of the collation source. This is used when the reading means 1001 and 1002 read data that is clearly different from the original electronic data used for irradiation by the writing laser unit 5, such as a preprint sheet or a tab sheet that is originally printed on the sheet. . If it falls below the matching judgment level β of the collation, it is judged as abnormal (the flowchart is FIG. 3).

  In the case of this second pattern, it cannot be determined immediately if the original first part is abnormal, but it can be determined that it is abnormal by comparing with the second and subsequent copies (normal sheets). In addition, it is possible to stabilize the determination of abnormality by having a trial mode and continuing the second and subsequent operations after visually confirming the output of the first portion. Furthermore, as a safety mode, it is also possible to obtain a stable output by reducing the sheet conveying speed only for the first part that becomes the data of the collation source during collation.

  In the third pattern, the first part is compared with the original electronic data used for irradiation by the writing laser unit 5, and the second and subsequent parts are read by the reading means 1001 and 1002 with the first part. The comparison is made as image data of the collation source. This is used when the background of the original sheet is slightly read, such as an embossed sheet, a resack sheet, etc., and is detected only when some of the eyes are clearly abnormal by setting the above-mentioned match judgment level α low. In the second and subsequent copies, the consistency in the output sheet can be increased by setting the above-described match determination level β to be high (the flowchart is FIG. 4).

  The match determination levels α and β of the first pattern and the second pattern are lowered to allow the occurrence of slight toner scattering during image formation. Β is set to a high value because it does not need to include a slight toner scatter during image formation.

  These three patterns are set to be automatically selected when selecting the sheet type. In addition to this, it is possible to set for each job and each output mode according to the user's preference, and the output quality can be selected as desired.

1 is a schematic configuration diagram of a digital composite copying machine (image forming apparatus) according to an embodiment of the present invention. Flowchart of the first embodiment Flowchart of the first embodiment Flowchart of the first embodiment

Claims (8)

In an image forming apparatus that forms image data on a sheet,
Reading means for reading the image or shape / posture of the image-formed sheet;
Collation data holding means having data to be collated with the read data read by the reading means;
Collating means for performing the collating operation;
A judgment means for judging whether or not a set threshold value is exceeded as a result of the matching,
An image forming apparatus characterized in that there are a plurality of collation data acquisition destinations of data to be collated entering the collation data holding means.   The image forming apparatus according to claim 1, wherein at least one of the plurality of collation data acquisition destinations is the reading unit.   2. The image forming apparatus according to claim 1, wherein two of the plurality of collation data acquisition destinations are the reading unit and the image data.   The image forming apparatus according to claim 1, wherein a threshold set in the determination unit is different depending on a destination of the collation data.   The image forming apparatus according to claim 3, wherein the threshold value set in the determination unit is lower in the image data between the reading unit from which the collation data is obtained and the image data.   2. The image forming apparatus according to claim 1, wherein which of the plurality of collation data acquisition destinations is selected is determined by the collation data holding unit by determining a job mode and a sheet type.   4. The image forming apparatus according to claim 3, wherein a part of the plurality of collation data acquisition destinations is the image data, and a part after the second part is the reading unit.   The image forming apparatus according to claim 7, wherein when reading the first portion by the reading unit, the sheet conveyance speed is slower than normal.

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