JP2005047048A - Sheet inspection equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide sheet inspection equipment capable of inspecting an output sheet normally even when the discharge speed from an image forming apparatus is switched. <P>SOLUTION: The sheet inspection equipment comprises a judgement means for judging whether a sheet is acceptable or not by comparing sheet information read out from a reader 501 with sheet information from a corresponding image forming apparatus, and a CPU 510 for controlling the reader 501 depending on the sheet carrying speed of a carrying roller. Upon receiving a line synchronization signal being generated at a specified period, the CPU 510 controls the reader 501 to take in data depending on the drive timing of a carrying motor 520 and sets the reading timing of the reader 501 such that the data is taken in by a closest line synchronization signal for each drive timing of the carrying motor 520. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００４８】
上記の式は、パターンＢ（ｉ，ｊ），パターンＰ（ｉ，ｊ）の重心を揃えたときのハミング距離を示すことになる。上記の式により算出したＣＯＲの値が大きい程、両者の類似度は大きいことになる。上記の演算にて類似度ＣＯＲが算出されると、あらかじめ設定してある閾値Ｔｈと類似度ＣＯＲとの比較を行う。すなわち、ＣＯＲ＞Ｔｈの場合には読み取った画像データが記憶装置内の画像データとほぼ同じであり、良品と判定される。また、ＣＯＲ＜Ｔｈの場合には、両者の画像データの類似度は低く、不良品と判定される。なお、閾値Ｔｈの値を変えることにより判定の精度を変更することが可能である。また、検品する画像データの種類に応じて閾値Ｔｈの値を変更することで、より柔軟な検品機能を提供することも可能である。
【００４９】
以上説明したように、本実施形態によれば、検品装置において、出力シートの画像を読取装置５０１で読み取る際に、出力シートを搬送する搬送ローラ５２１，５２２の搬送モータ５２０の駆動タイミングに応じて、読取装置５０１の読取タイミングを設定するため、画像形成装置からのシート排出速度が違う場合においても、一定のライン数で出力シートを読み取ることができ、該出力シートの（特にシート搬送方向である副走査方向の）検品を正常に行うことができる。
【００５０】
〔他の実施形態〕
前述した実施形態では、検品装置を独立した装置として説明したが、これに限定されるものではなく、たとえば画像形成装置本体と一体となっていても良いことはもちろんである。また、検品装置の下流側に後処理装置を装着しているが、これに限らず、スタッカ等の単なる積載手段でも良いことはもちろんである。また、検品装置における読取装置として、ＣＣＤやＣＩＳ等を例示したが、これに限らなくても良いことももちろんである。
【００５１】
なお、本発明の様々な実施形態を示し説明したが、本発明の趣旨と範囲は本明細書内の特定の説明と図に限定されるものではない。以下、本発明の実施態様の例を列挙する。
【００５２】
〔実施態様１〕
シートを搬送する搬送手段を駆動する駆動手段と、前記搬送手段によって搬送されるシートの画像及び形状等の情報を読み取り、読み取ったデータを所定周期で出力する読取手段と、画像形成装置から送信される各シートに対応した情報を検品装置に伝達するための検品データ通信手段と、前記読取手段により読み取ったシート情報と、これに対応した前記画像形成装置からのシート情報とを比較し、該シートの良否を判定する判定手段と、前記搬送手段によるシートの搬送速度に応じて前記読取手段を制御する制御手段と、を有し、前記制御手段は、所定の周期で発生するライン同期信号が入力されると、前記駆動手段の駆動タイミングに応じて前記読取手段によるデータ取り込みを行い、且つ前記読取手段による読取タイミングを、前記駆動手段の駆動タイミング毎に最も近いライン同期信号でデータの取り込みを行うように設定することを特徴とするシート検品装置。
【００５３】
〔実施態様２〕
実施態様１において、前記駆動手段の駆動タイミングを制御すると共に前記読取手段から出力されるデータを取り込むタイミングを制御する制御手段を有し、前記制御手段は、前記搬送手段によるシートの搬送速度が、画像形成装置からの排出速度になるように駆動タイミングを与え、前記駆動タイミングに基づいて、前記読取手段から出力されるデータを選択的に取り込む制御を行うことを特徴とするシート検品装置。
【００５４】
【発明の効果】
以上説明したように、本発明によれば、出力シートの画像を読み取る際に、出力シートの搬送モータの駆動タイミングに応じて、読取タイミングを設定するため、画像形成装置からのシート排出速度が違う場合においても、一定のライン数で出力シートを読み取ることができ、シートの（特にシート搬送方向である副走査方向の）検品を正常に行うことができる。
【図面の簡単な説明】
【図１】画像形成装置本体、シート検品装置、及び後処理装置からなるシステム全体の概略構成を示す模式説明図
【図２】画像形成装置本体の概略構成を示す説明図
【図３】後処理装置の概略構成を示す説明図
【図４】シート検品装置の概略構成を示す説明図
【図５】シート検品装置の一実施形態を示すブロック図
【図６】シート検品装置の一実施形態の動作を表すフローチャート
【図７】シート検品装置の一実施形態の読み取り動作を表す図
【図８】シート検品装置と画像形成装置本体間のコマンドの例を表す図
【図９】画像データのパターン例を示す図
【符号の説明】
Ａ …走査本体
Ｂ …スキャナ部
Ｃ …画像形成部
Ｄ …シートデッキ
Ｐ …シート
Ｕ１，Ｕ２ …給送ユニット
１ …シートカセット
１ａ，１ｂ …カセット
３ …ピックアップローラ
４ …フィードローラ
５ …リタードローラ
６ …手差しトレイ
７ …給送ローラ
１００ …画像形成装置
１０４，１０５ …搬送ローラ
１０６ …レジストローラ
１１１ …レーザスキャナ
１１２ …電子写真感光体ドラム
１１３ …画像書き込み光学系
１１４ …現像器
１１５ …転写帯電器
１１７ …搬送部
１１８ …定着装置
１１９ …排出ローラ
１２１ …シート両面トレイ
２０１ …走査系光源
２０２ …プラテンガラス
２０３ …原稿圧板
２０４ …ミラー
２０５ …レンズ
２０６ …受光素子（光電変換素子）
２０７ …分岐点
３００ …後処理装置
３０１ …制御回路
３０２ …入口ローラ対
３０３ …搬送ローラ対
３０５ …搬送大ローラ
３０６ …搬送ローラ
３０７ …排出ローラ
３０９ …排出ローラ
３１０ …切換フラッパ
３１１ …切換フラッパ
３１２，３１３，３１４ …押圧コロ
３１５ …揺動ガイド
３１６ …処理トレイ
３１８ａ …下部束排出ローラ
３１８ｂ …上部束排出ローラ
３２０ …スタックトレイ
３２１ …ノンソートパス
３２２ …ソートパス
３２３ …バッファパス
３３１ …シート検知センサ
３３２，３３３ …シート検知センサ
３４０ …ステイプラ
３５０ …パンチユニット
５００ …検品装置
５０１ …読取装置
５０２ …バッファトレイ
５０３ …再給送手段
５０４ …搬送路
５０５ …検品トレイ
５０６，５０７ …フラッパ
５０８ …搬送パス
５０９ …搬送パス
５１０ …ＣＰＵ
５１１ …記憶装置
５１２ …比較装置
５１３ …分岐パス
５１４ …操作部
５２０ …搬送モータ
５２１，５２２ …搬送ローラ
６０３ …ＲＯＭ
６０４ …ＲＡＭ
６０５ …Ｉ／Ｏ
６０８ …センサ
６０９ …Ｉ／Ｏ
６１０ …ＣＰＵ
６１１ …スキャナ
６１２ …ＲＯＭ
６１３ …ＲＡＭ
６１４ …記憶装置
６１５ …画像メモリ
６１６ …光電変換部
６１７ …ＡＤ変換部
６１８ …クロック発生部
６１９ …データ変換部
９０１ …基本フォーマット
９０２ …排出コマンド
９０３ …再スタートコマンド
９０４ …不良出力シート検知コマンド[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet inspection apparatus that inspects a sheet on which an image is formed, such as a sheet output from an image forming apparatus such as a copying machine.
[0002]
[Prior art]
Conventionally, a sheet output from an image forming apparatus such as a copying machine is used as it is or processed as a bundle by a post-processing device such as a finisher, that is, bundle discharge processing, binding processing, punching processing, folding processing, and the like. Post-processing such as processing, bookbinding processing, and sorting processing can be performed. In these cases, modes such as a cover mode and a slip sheet mode can be set. A cassette provided in the image forming apparatus or a paper feed tray is provided on the first page, last page, or intermediate page of the paper. It is possible to insert a sheet supplied from. For this reason, it is possible to feed a “cover” or “interleaf” by feeding a bundle that is not only a single type of sheet, specifically from another paper feed stage or from a special tray on which an “insertion sheet” is placed. , Different types of sheets can be inserted as “back cover”.
At this time, regarding the processing of the sheet for insertion, since it is a simple sheet conveying operation, the number of inserted sheets (location) and the number of inserted sheets can be arbitrarily set.
[0003]
[Problems to be solved by the invention]
However, there are various misprints such as output sheet image defects due to image forming apparatus defects, image skew, paper wrinkles and ear folds, density defects and color misregistration, and paper color differences due to paper setting errors. It can happen. However, after these are output from the image forming apparatus, it has not been determined whether or not they are normal. Therefore, for example, even when the image transferred to the sheet contacts the structure on the traveling path before being completely fixed, the output is continued as it is. In addition, when a bookbinding process is performed by a post-processing apparatus such as a finisher, it is treated as a defective book as a single book due to a defective sheet, and not only a defective sheet but also other sheets. There is a problem that even a normal sheet is wasted.
[0004]
Further, in order to inspect the above-described defect of the image forming apparatus, the output sheet is read by a reading unit such as a scanner, and the data sent from the image forming apparatus is compared with the data read by the reading unit such as a scanner. The image forming apparatus may have different discharge speeds depending on the model or material. Therefore, there is a problem that the output sheet cannot always be read with the same number of lines, and inspection in the sub-scanning direction (sheet conveyance direction) cannot be performed.
[0005]
An object of the present invention is to provide a general-purpose sheet inspection apparatus that can inspect an output sheet even when the discharge speed from the image forming apparatus is switched depending on the model or material of the image forming apparatus to be mounted. It is.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a typical configuration of the present invention includes a conveying unit that conveys a sheet, a driving unit that drives the conveying unit, and information such as an image and a shape of the sheet conveyed by the conveying unit. Reading means for reading and outputting the read data in a predetermined cycle, inspection data communication means for transmitting information corresponding to each sheet transmitted from the image forming apparatus to the inspection apparatus, and sheet information read by the reading means A determination unit that compares the sheet information from the image forming apparatus corresponding thereto and determines the quality of the sheet, and a control unit that controls the reading unit in accordance with the sheet conveyance speed by the conveyance unit; When the line synchronization signal generated at a predetermined cycle is input, the control unit sends the reading unit to the reading unit at a timing according to the conveyance speed of the conveyance unit. That perform data acquisition, and the reading timing by the reading means, and sets to perform closest line synchronizing signal in the data capture every timing corresponding to the conveying speed of the conveying means.
[0007]
In the above configuration, the timing according to the transport speed of the transport unit is a drive timing of the drive unit.
[0008]
According to the above configuration, it is possible to provide a general-purpose sheet inspection apparatus that can inspect an output sheet even when the sheet discharge speed from the image forming apparatus is switched depending on the model or material of the image forming apparatus. It is.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the following embodiments should be changed as appropriate according to the configuration of the apparatus to which the present invention is applied and various conditions. As long as there is no specific description, it is not the meaning which limits the scope of the present invention only to them.
[0010]
[First Embodiment]
An image forming apparatus and an inspection apparatus according to an embodiment of the present invention will be described with reference to FIGS.
[0011]
{Overview of the entire system}
FIG. 1 is an overall configuration diagram of an image forming apparatus system according to an embodiment of the present invention, and includes an image forming apparatus 100, an inspection apparatus 500, and a post-processing apparatus 300. Each will be described below.
[0012]
{Overall configuration of image forming apparatus body}
With reference to FIG. 2, the overall schematic configuration of the image forming apparatus according to the embodiment of the present invention will be described along the flow of sheets. Note that a copying machine will be described as an example of an image forming apparatus.
[0013]
In FIG. 2, an image forming apparatus main body 100 has a scanner unit B as an image reading unit that reads image information of a book document at an upper portion thereof, and an image forming unit C as an image forming unit at a lower portion thereof. The seat deck D is assembled to the lower part thereof.
[0014]
The scanner section B includes a scanning light source 201, a platen glass 202, a document pressure plate 203 that can be opened and closed with respect to the scanning body A, a mirror 204, a lens 205, a light receiving element (photoelectric conversion element) 206, an image processing section, and the like. Configured. A book document such as a book, cardboard, or curl paper, or a sheet-like document is placed on the platen glass 202 with the document surface facing downward, and the back surface is pressed by the document pressure plate 203 and set in a stationary state. When pressed, the scanning light source 201 scans the lower part of the platen glass 202 in the direction of arrow a in FIG. Image information of the original read by the scanning light source 201 is processed by an image processing unit, converted into an electrical signal, and transmitted to the laser scanner 111.
[0015]
The image forming apparatus main body 100 functions as a copying machine when a processing signal of an image processing unit is input to the laser scanner 111, and functions as a printer when an output signal of a computer is input. If a signal from another facsimile apparatus is received or a signal from the image processing unit is transmitted to another facsimile apparatus, it can function as a facsimile apparatus.
[0016]
On the other hand, a sheet cassette 1 is attached to the lower part of the image forming unit C. In this embodiment, two feeding units U1 and U2 are attached, and two (total four) cassettes 1a and 1b are provided. I try to wear it. After the sheets accommodated in the cassettes 1a and 1b are fed out by the pickup roller 3 serving as a feeding rotating body, and separated and fed one by one by the cooperative action of the feed roller 4 and the retard roller 5. Then, it is conveyed by the conveying rollers 104 and 105, guided to the registration roller 106, and fed to the image forming unit C by the registration roller 106 so as to be synchronized with the image forming operation.
[0017]
The image forming unit C includes an electrophotographic photosensitive drum 112, an image writing optical system 113, a developing device 114, a transfer charger 115, and the like. Laser light corresponding to the image information emitted from the laser scanner 111 is scanned on the surface of the photosensitive drum 112 uniformly charged by the charger by the image writing optical system 113 to form a latent image. A toner image is formed by the developing device 114, and the toner image is transferred to the first surface of the sheet by the transfer charger 115 onto the sheet conveyed by the registration roller 106 in synchronization with the rotation of the photosensitive drum 112.
[0018]
Reference numeral 117 denotes a conveyance unit that conveys a sheet on which a toner image is formed, 118 denotes a fixing device, and 119 denotes a discharge roller. The sheet on which the toner image is formed is conveyed to the fixing device 118 by the conveyance unit 117, and is heated and pressurized to fix the toner image on the sheet surface, and is then discharged out of the apparatus by the discharge roller 119.
[0019]
When recording images on both sides of the sheet, the sheet discharged from the fixing device 118 is sandwiched between the discharge rollers 119, and when the rear end of the sheet passes through the branching point 207, the discharge roller 119 reverses and the sheet is discharged. After the sheet is once placed on the double-sided tray 121, the sheet is conveyed by the conveying rollers 104 and 105, reaches the registration roller 106, and the inverted sheet is formed with an image on the second surface in the same manner as described above. Discharged. Further, it is also possible to reversely discharge a sheet with an image formed on one side via the branch path 207.
[0020]
In FIG. 2, 6 is a manual feed tray, and 7 is a feed roller that separates and feeds sheets set on the manual feed tray 6 one by one.
[0021]
{Overall configuration of post-processing device}
In FIG. 3, the post-processing apparatus 300 receives the sheet discharged from the inspection apparatus 500 from the entrance roller pair 302 and conveys the sheet into the interior. A conveyance roller pair 303 is provided downstream of the entrance roller pair 302, and a sheet detection sensor 331 is provided between the entrance roller pair 302 and the conveyance roller pair 303.
[0022]
A punch unit 350 is provided downstream of the conveying roller pair 303, and downstream of the punch unit 350 are arranged large conveying rollers 305 and pressing rollers 312, 313, and 314 that press and convey the surrounding sheets.
[0023]
The switching flapper 311 switches between a non-sorting path 321 and a sorting path 322. A switching flapper 310 at the entrance of the sort path 322 switches between the sort path 322 and the buffer path 323 for temporarily storing sheets.
[0024]
A conveyance roller 306 is provided in the sort path 322. On an intermediate tray (hereinafter referred to as “processing tray”) 316 as a stacking tray disposed downstream of the sort path 322, sheets can be temporarily stacked, aligned, stapled, and the like.
[0025]
A discharge roller 307 at the exit of the sort path 322 discharges the sheet onto the processing tray 316. The upper bundle discharge roller 318b is supported by the swing guide 315. When the swing guide 315 moves to the closed position, the upper bundle discharge roller 318b cooperates with the lower bundle discharge roller 318a disposed on the processing tray 316 to remove the sheet on the processing tray 316. The bundle is conveyed and discharged onto the stack tray 320.
[0026]
That is, the swing guide 315 is tilted, and the lower bundle discharge roller 318a and the upper bundle discharge roller 318b form a roller pair to convey the sheets on the processing tray 316 in a bundle.
[0027]
In FIG. 3, P is a sheet, 301 is a control circuit, 309 is a discharge roller, 332 and 333 are sheet detection sensors, and 340 is a stapler.
[0028]
{Overall configuration of inspection equipment}
With reference to FIG. 4, the overall schematic configuration of the inspection apparatus according to the embodiment of the present invention will be described.
[0029]
Reference numeral 504 denotes a first conveyance path for receiving a sheet output from the image forming apparatus main body 100. The conveyance path 504 is connected to an outlet that delivers the sheet to the post-processing apparatus 300. Reference numerals 521 and 522 denote conveyance rollers that convey the output sheet, and are driven by a conveyance motor 520. Reference numeral 501 denotes a reading device as reading means for reading sheet information such as an image, color, and outer shape of the sheet. The reading device 501 is arranged such that a CCD, CIS, or the like reads both sides of a sheet. The reading width is equal to or greater than the maximum sheet passing width, and is sufficient for reading the outer shape of the sheet.
[0030]
Reference numerals 506 and 507 denote flappers as switching means for switching the sheet conveying direction. A flapper 506 serving as a first switching unit is for guiding a sheet to a branch path 513 that is a second conveyance path branched from the first conveyance path 504, and at least the maximum sheet passing sheet from the reading device 501. It is arranged at a position more than a long distance. A flapper 507 serving as a second switching unit is for guiding a sheet to a conveyance path 508 that is a third conveyance path branched from the branch path 513.
[0031]
Reference numerals 502 and 505 denote trays as holding means for stacking sheets guided by the flappers 506 and 507. A re-feeding means 503 is provided in the buffer tray 502 as the second holding means. A sheet is guided to the buffer tray 502 by a conveyance path 508. The tray 502 and the conveyance path 508 are arranged so that the sheet re-fed from the buffer tray 502 passes through the reading device 501 again. An inspection tray 505 serving as a first holding unit stacks sheets guided by a conveyance path 509 that forms a second conveyance path together with the branch path, and is exposed to the outside of the inspection apparatus main body.
[0032]
Reference numeral 511 denotes a storage device as storage means for storing image data read by the reading device 501. Reference numeral 512 denotes a comparison device for comparing the read image with reference data. A CPU 510 serves as a control unit that controls the operation of the inspection apparatus 500 and the image forming apparatus main body 100 and the post-processing apparatus 300. Reference numeral 514 denotes an operation unit which is used when a state of the inspection apparatus 500 or an operation instruction to be described later is performed.
[0033]
{Block diagram of the control system of the entire device}
In FIG. 5, reference numeral 510 denotes a CPU as control means of the inspection apparatus, which performs sequence control of the entire inspection apparatus, data handling, and scanner reading timing control. Reference numeral 511 denotes a storage device, which is composed of a hard disk or the like for storing image data of the output sheet read by the reading device (scanner) 501 in the inspection device. Reference numeral 603 denotes a ROM for storing a program for operating the CPU 510. A RAM 604 supplies a working area necessary for the CPU 510 to operate. Reference numeral 605 denotes an I / O serving as a communication unit, which performs serial communication with the image forming apparatus and monitors a sensor for detecting sheet input. Reference numeral 501 denotes a reading device, which is a scanner for reading an image on an output sheet discharged from the image forming apparatus and converting it into electronic data. Reference numeral 616 denotes a photoelectric conversion unit that converts the read image into an electric signal. Reference numeral 617 denotes an AD conversion unit that converts the electrical signal output from the photoelectric conversion unit 616 into a binary digital signal. Reference numeral 618 denotes a clock generator that generates a line synchronization signal for each line. Reference numeral 619 denotes a data conversion unit that converts binarized data into signals that can be easily handled by the CPU 510 by the AD conversion unit 617. Reference numeral 608 denotes a sensor for detecting an output sheet from the image forming apparatus. A conveyance motor 520 drives the conveyance rollers 521 and 522.
[0034]
On the other hand, on the image forming apparatus side, reference numeral 609 denotes an I / O as communication means for performing serial communication with the inspection apparatus. A CPU 610 serves as a control unit that performs sequence control and data handling of the entire image forming apparatus. Reference numeral 611 denotes a scanner for reading a document to be copied and converting it into electronic data. Reference numeral 612 denotes a ROM for storing a program for operating the CPU 610. Reference numeral 613 denotes a RAM that provides a working area necessary for the CPU 610 to operate. A storage device 614 is configured by a hard disk or the like in order to store image data of a document read by the scanner 611. Reference numeral 615 denotes an image memory for developing an image in order to form an image of the original image data read by the scanner 611 and converted into electronic data on a sheet.
[0035]
{Inspection sequence}
FIG. 6 is a flowchart of a sequence of a series of inspection operations in the inspection apparatus. Step S601 is a portion waiting for input of an output sheet from the image forming apparatus. This input is detected by a sensor 608 (see FIG. 5) in the inspection device. Step S602 is a process of reading an output sheet input from the image forming apparatus with a reading device (scanner) 501 in the inspection apparatus and converting it into electronic data. At this time, the image forming apparatus transmits the copy data, the page number data, the image data, and the feature data to the inspection apparatus through serial communication in synchronization with the discharge of the sheet. The image data is image data read by the scanner 611 (see FIG. 5) on the image forming apparatus side or image data in the image memory 615 (see FIG. 5). In step S603, the output sheet data obtained by the reading device (scanner) 501 is compared with the image data and feature data acquired from the image forming device to determine whether or not the product is acceptable. If it is determined to be normal (OK), the process proceeds to input waiting for the next output sheet (the process proceeds to step S601), and if determined to be abnormal (NG), the image forming apparatus detects a defective output sheet in step S604. Notify the command via serial communication and stop the copying operation.
[0036]
{Reading control}
Next, reading control in the inspection apparatus 500 will be described with reference to FIG. 7 (and FIGS. 4 and 5). FIG. 7 shows the timing at which the reading data is read by the reading device 501 in synchronization with the step operation of the conveying motor 520 that drives the conveying rollers 521 and 522 in order to read the reading data by the reading device 501 at a timing according to the conveying speed. It is shown.
[0037]
The line synchronization signal 702 is set so as to be generated in the same cycle as the CCD accumulation time in the photoelectric conversion unit 616, and is input to the photoelectric conversion unit 616 and the CPU 510, and the reading operation by the reading device 501 is performed based on this signal. Is called.
[0038]
When the line synchronization signal 702 is input to the photoelectric conversion unit 616, the accumulated charges are transferred to a shift register in the CCD, converted into an electrical signal, and transferred to the AD conversion unit 617 pixel by pixel. Data binarized by the AD conversion unit 617 is transferred to the data conversion unit 619 and converted into a signal that can be easily handled by the CPU 510.
[0039]
When the line synchronization signal 702 is input, the CPU 510 serving as a control unit captures data for one line from the data conversion unit 619 in accordance with the drive timing 701 of the transport motor 520. The drive timing 701 of the carry motor 520 is different from the line synchronization signal 702. Therefore, since it is impossible to set the reading timing 703 by the reading device 501 by combining the driving timing 701 of the conveying motor 520 and the line synchronization signal 702, as shown in FIG. The reading timing 703 by the reading device 501 is set so that data is taken in by the near line synchronization signal 702.
[0040]
As described above, in order to capture one line of data of the output sheet by the reading device 501 (data conversion unit 619) in synchronization with the drive timing 701 of the conveyance motor 520 that drives the conveyance rollers 521 and 522, the output sheet Even when the conveyance speed is different, it can be read with the same number of lines. Therefore, even when the sheet discharge speed from the image forming apparatus is switched depending on the model or material of the image forming apparatus to be mounted, the inspection of the output sheet (especially the sub-scanning direction which is the sheet conveying direction) should be performed normally. Can do.
[0041]
In the reading control described above, the driving timing of the transport motor 502 is used so that the reading data is read by the reading device 501 at a timing according to the transport speed. The timing according to the transport speed is the driving timing of the transport motor. It is not limited to. For example, a new data acquisition timing corresponding to the conveyance speed may be generated, and one line of data on the output sheet by the reading device 501 may be acquired in synchronization with the acquisition timing.
[0042]
{Communication command}
FIG. 8 shows an example of a command for performing serial communication between the inspection apparatus and the image forming apparatus via I / O which is communication means. Reference numeral 901 denotes a basic command format. Each data of the command is composed of an ASCII code, and the first two bytes are an ID part, which represents the type of command and the communication direction. Commands with IDs 00 to 7F are transmitted from the image forming apparatus to the inspection apparatus, and commands with 80 to FF are transmitted from the inspection apparatus to the image forming apparatus. The next parameter section is an area where, if more information needs to be added for each command, that information is converted into ASCII data and stored. The checksum part is information added to detect a communication error, and is obtained by converting a value added in units of 1 byte from the head of the command into ASCII data. The same calculation is performed on the side that receives the command, and if the received checksum value is the same, it is determined that no communication error has occurred. The next Cr and Lf are delimiters and are data representing the end of the command. The basic format configuration is as described above, and examples of each command are shown below.
[0043]
Reference numeral 902 denotes a discharge command for representing information of the discharged output sheet, which is transmitted from the image forming apparatus to the inspection apparatus in synchronization with the output sheet. The command ID is 0 or 1. Subsequently, in order to distinguish each copy job, a job ID assigned a unique value for each copy job, the number of copies data indicating the number of copies in the copy job, and the number of copies The page number representing the current page, output sheet image data, output sheet characteristic data (color, tab position, and other information), and data indicating whether the page is the last page are stored in the parameter section.
[0044]
Reference numeral 903 denotes a restart command, which is transmitted from the inspection apparatus to the image forming apparatus by adding a corresponding job ID when the confirmed switch on the inspection apparatus is pressed after the first copy is completed. When the image forming apparatus receives this command, it outputs the second and subsequent copies of the job specified by the job ID.
[0045]
A defect output sheet detection command 904 is transmitted from the inspection apparatus to the image forming apparatus when the inspection apparatus detects a defective sheet. When the image forming apparatus receives this command, it immediately stops the image forming operation and notifies the operator to that effect.
[0046]
{Judgment means}
Next, an output sheet quality determination unit will be described. The output sheet pass / fail judgment means is a similarity between the data read by the reading device in the inspection device and the image data transmitted from the image forming device (or image data stored in a storage device in the inspection device). Is calculated. Various methods can be considered as a method for calculating the degree of similarity. Here, an example will be described. FIG. 9A shows a pattern of image data read by the reading device (scanner) 501 in the inspection device in this embodiment, and FIG. 9B shows a pattern of image data stored in the storage device. Respective patterns are expressed as B (i, j) and P (i, j). B (i, j) and P (i, j) take a value of “1” for black pixels and “0” for white pixels. Also, assuming that the center-of-gravity coordinates of B (i, j) and P (i, j) are (ibc, jbc) and (ipc, jpc), the similarity COR between them is expressed by the following equation.
[0047]
[Expression 1]

[0048]
The above expression indicates the Hamming distance when the centers of gravity of the patterns B (i, j) and P (i, j) are aligned. The greater the COR value calculated by the above equation, the greater the similarity between the two. When the similarity COR is calculated by the above calculation, the preset threshold Th is compared with the similarity COR. That is, when COR> Th, the read image data is almost the same as the image data in the storage device, and is determined to be a non-defective product. When COR <Th, the similarity between the two image data is low, and the product is determined to be defective. Note that the accuracy of determination can be changed by changing the value of the threshold Th. It is also possible to provide a more flexible inspection function by changing the value of the threshold Th according to the type of image data to be inspected.
[0049]
As described above, according to the present embodiment, in the inspection apparatus, when the image of the output sheet is read by the reading device 501, the reading roller 501 conveys the output sheet according to the drive timing of the conveying motor 520 of the conveying rollers 521 and 522. Since the reading timing of the reading device 501 is set, the output sheet can be read with a certain number of lines even when the sheet discharge speed from the image forming apparatus is different, and the output sheet (especially in the sheet conveyance direction) can be read. Inspection in the sub-scanning direction can be performed normally.
[0050]
[Other Embodiments]
In the above-described embodiment, the inspection device has been described as an independent device, but the invention is not limited to this. For example, the inspection device may be integrated with the image forming apparatus main body. Further, the post-processing device is mounted on the downstream side of the inspection device. However, the present invention is not limited to this, and it goes without saying that a simple stacking means such as a stacker may be used. Moreover, although CCD, CIS, etc. were illustrated as a reader in an inspection apparatus, it is needless to say that it is not limited to this.
[0051]
In addition, although various embodiment of this invention was shown and demonstrated, the meaning and scope of this invention are not limited to the specific description and figure in this specification. Examples of embodiments of the present invention are listed below.
[0052]
[Embodiment 1]
A driving unit that drives a conveying unit that conveys a sheet, a reading unit that reads information such as an image and a shape of a sheet conveyed by the conveying unit, and outputs the read data in a predetermined cycle, and a transmission unit that transmits Inspection data communication means for transmitting information corresponding to each sheet to the inspection apparatus, sheet information read by the reading means, and sheet information from the image forming apparatus corresponding thereto are compared, and the sheet And a control unit that controls the reading unit in accordance with a sheet conveyance speed by the conveyance unit, and the control unit receives a line synchronization signal generated at a predetermined cycle. Then, data is read by the reading unit according to the driving timing of the driving unit, and the reading timing by the reading unit is Sheet inspection apparatus characterized by setting to perform data capture in the nearest line synchronizing signal every driving timing of the motion means.
[0053]
[Embodiment 2]
In the first exemplary embodiment, the control unit includes a control unit that controls a driving timing of the driving unit and a timing at which the data output from the reading unit is fetched, and the control unit has a conveyance speed of the sheet by the conveyance unit, A sheet inspection apparatus, wherein a drive timing is given so as to be a discharge speed from the image forming apparatus, and control is performed to selectively take in data output from the reading unit based on the drive timing.
[0054]
【The invention's effect】
As described above, according to the present invention, when the image of the output sheet is read, the reading timing is set according to the drive timing of the output sheet conveyance motor, so the sheet discharge speed from the image forming apparatus is different. Even in this case, the output sheet can be read with a certain number of lines, and the inspection of the sheet (especially in the sub-scanning direction which is the sheet conveying direction) can be performed normally.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory diagram illustrating a schematic configuration of an entire system including an image forming apparatus main body, a sheet inspection apparatus, and a post-processing apparatus.
FIG. 2 is an explanatory diagram showing a schematic configuration of an image forming apparatus main body.
FIG. 3 is an explanatory diagram showing a schematic configuration of a post-processing apparatus.
FIG. 4 is an explanatory diagram showing a schematic configuration of a sheet inspection apparatus.
FIG. 5 is a block diagram showing an embodiment of a sheet inspection apparatus.
FIG. 6 is a flowchart showing the operation of one embodiment of the sheet inspection apparatus.
FIG. 7 is a diagram illustrating a reading operation of the sheet inspection apparatus according to the embodiment.
FIG. 8 is a diagram illustrating an example of a command between the sheet inspection apparatus and the image forming apparatus main body.
FIG. 9 is a diagram showing an example pattern of image data
[Explanation of symbols]
A ... Scanning body
B ... Scanner section
C: Image forming unit
D ... Seat deck
P ... sheet
U1, U2 ... Feeding unit
1 ... Sheet cassette
1a, 1b ... cassette
3 ... Pickup roller
4 ... Feed roller
5 ... retard roller
6 ... Bypass tray
7: Feed roller
100: Image forming apparatus
104, 105 ... transport rollers
106… Registration roller
111 ... Laser scanner
112 ... Electrophotographic photosensitive drum
113 ... Image writing optical system
114… Developer
115… Transfer charger
117 ... Conveying section
118... Fixing device
119 ... discharge roller
121 ... Sheet double-sided tray
201 ... Scanning system light source
202 ... Platen glass
203 ... Original platen
204… Mirror
205… Lens
206. Light receiving element (photoelectric conversion element)
207… Branching point
300 ... post-processing apparatus
301 ... Control circuit
302… Inlet roller pair
303 ... Conveying roller pair
305 ... Large transfer roller
306 ... Conveying roller
307 ... discharge roller
309 ... discharge roller
310 ... switching flapper
311 ... switching flapper
312,313,314 ... Pressing roller
315: Swing guide
316 ... processing tray
318a ... Lower bundle discharge roller
318b ... Upper bundle discharge roller
320 ... Stack tray
321 ... Non-sort path
322 ... Sort path
323 ... Buffer path
331: Sheet detection sensor
332, 333 ... Sheet detection sensor
340 ... stapler
350 ... punch unit
500 ... Inspection equipment
501 ... Reading device
502 ... Buffer tray
503 ... Refeed means
504 ... Conveyance path
505 ... Inspection tray
506, 507 ... Flapper
508 ... Transport path
509 ... Transport path
510 ... CPU
511 ... Storage device
512… Comparison device
513 ... Branch path
514 ... operation unit
520 ... Conveyance motor
521, 522 ... Conveying roller
603 ROM
604 ... RAM
605 ... I / O
608 sensor
609 ... I / O
610 ... CPU
611 Scanner
612 ... ROM
613 ... RAM
614 Storage device
615 ... Image memory
616 ... Photoelectric conversion unit
617 ... AD converter
618 ... Clock generator
619 ... Data converter
901 ... Basic format
902 ... Discharge command
903 ... Restart command
904 ... Defective output sheet detection command

Claims (2)

Conveying means for conveying the sheet;
Driving means for driving the conveying means;
Reading means for reading information such as an image and a shape of a sheet conveyed by the conveying means, and outputting the read data at a predetermined period;
Inspection data communication means for transmitting information corresponding to each sheet transmitted from the image forming apparatus to the inspection apparatus;
A determination unit that compares the sheet information read by the reading unit with the sheet information from the image forming apparatus corresponding to the sheet information, and determines the quality of the sheet;
Control means for controlling the reading means in accordance with the conveying speed of the sheet by the conveying means,
When the line synchronization signal generated at a predetermined cycle is input, the control unit captures data by the reading unit at a timing according to the conveyance speed of the conveyance unit, and sets the reading timing by the reading unit to A sheet inspection apparatus, wherein the sheet inspection apparatus is set so as to capture data with the closest line synchronization signal at each timing according to the conveyance speed of the conveyance means. The sheet inspection apparatus according to claim 1, wherein the timing according to the conveying speed of the conveying unit is a driving timing of the driving unit.

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