JP2005143018A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To equalize document feeding speeds using respective drives by automatic control in an image reading apparatus including an ADF that feeds a document using different driving sources for paper supply and paper ejection. <P>SOLUTION: The image reading apparatus includes a paper supply driving means, a paper supply drive control means, a paper ejection driving means, a paper ejection drive control means, and a document feeding speed measuring means dependent upon the paper ejection driving means. The speed of the paper supply drive control means or the paper ejection drive control means is corrected to be equal with a document reading speed by the document feeding speed measuring means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus and a method of using the same, and more particularly to a method of controlling a speed for sequentially feeding and conveying a plurality of sets of documents.

  FIG. 7 shows a cross-sectional view of a conventional image reading apparatus.

  2. Description of the Related Art Conventionally, an image reading apparatus provided with an automatic paper feeder (hereinafter referred to as ADF) 22 that sequentially or continuously supplies originals with the same page order without using a sorter, and feeds and conveys them to a reading position. It is conventionally known to do. In such an apparatus, an original composed of a set of individual sheets is sequentially supplied to an optical exposure apparatus in order to read an image.

  Conventionally, a document set and arranged for each sheet in the sheet feeding unit of the ADF 22 is picked up by a semi-moon-shaped pickup roller 14. A sheet feeding motor 24 drives the pickup roller 14 and the sheet feeding roller 3 by a belt 25 and a shaft (not shown). The document fed by the pickup roller 14 is conveyed for each sheet by the sheet feed roller 3 and reaches the image reading position and the sheet discharge roller. Further, the original is discharged to a discharge stacker by a discharge roller. The shaft 26 of the paper feed motor 24 is driven in the A direction when picking up, and is driven in the B direction when the paper feed motor 24 is driven. Since the next document 2 must be picked up at the timing when the paper discharge roller 8 is driven, the paper discharge roller 8 is driven by a paper discharge motor (not shown) separate from the paper feed motor 24.

  Normally, when the ADF 22 is assembled, adjustment is made so that the document conveying speed of the sheet feeding roller 3 by the sheet feeding motor 24 and the document conveying speed by the sheet discharge roller 8 are the same. As a method for adjusting the conveyance speed, an adjustment chart (FIG. 7B) is set in the ADF 22 and an image is read. The read image data is stored in a memory for storing the image data, and the image is evaluated. In the adjustment chart, a plurality of lines perpendicular to the transport direction are arranged at equal intervals, the leading end is driven only by the paper feed roller 3, and the rear end is driven only by the paper discharge roller 8. It has become. Image sizes P and P 'of the area of interest of the stored image data are measured. In each of the measured attention areas, the same image is read, and the expansion and contraction of the image size is the difference between the document transport speed of the paper feed roller 3 by the paper feed motor 24 and the document transport speed of the paper discharge roller 8. In the adjustment chart, if the image size driven by the paper discharge roller 8 alone is shorter than the image size driven by the paper feed roller 3 alone, the speed of the paper discharge motor is reduced, and if it is longer than the image size, the paper is discharged. The speed of the motor is increased, and the document conveyance speed by the paper discharge roller 8 is adjusted. This adjustment is repeated until the image sizes match.

An example of an image reading apparatus equipped with an ADF is Patent Document 1.
Japanese Patent Laid-Open No. 9-281756

  However, a specific chart is required to adjust the conveyance speed, and it takes time until the adjustment is completed, and it is necessary to load the adjustment chart on the ADF. .

  In addition, in order to perform evaluation using images, tools such as a huge memory for storing images and software for performing evaluation are required.

  In addition, the speed of feeding by the paper feed roller and paper discharge roller can be adjusted even though adjustments have been made due to wear of rollers, gears, depletion of grease, etc. In some cases, reading accuracy deteriorated and jamming occurred.

According to the first invention of the present invention,
An image reading apparatus having an automatic paper feeder that reads a document image line by line while sequentially feeding a plurality of sheet-like documents and transporting them to a predetermined reading position, and a document reading mode for reading an actual document An adjustment mode for performing adjustment before reading, and in the adjustment mode, a paper feed roller for picking up a document for each sheet, a paper feed roller driving means for driving the paper feed roller, and the paper feed roller drive means The document feeding speed is controlled so as to be the document reading speed, and the sheet feeding roller conveys the fed sheet document to the reading position, and discharges the sheet after passing the document reading position and the sheet discharging roller. A discharge roller driving means for driving and a first document detection means installed at a predetermined position upstream of the paper feed roller for detecting the presence or absence of a document, between the paper feed roller and the transport roller A second document detection unit that detects a document that is installed at a fixed location and that is conveyed from a paper feed roller, and a third document detection unit that detects a document that is installed at a predetermined location downstream of the conveyance roller and is discharged from the conveyance roller. The document detection time is measured by each of the document detection means, and when the document conveyance speed is the document reading speed, the passage time is set as a reference time, and the reference time is compared with the measurement time, and the discharge roller driving means To control the document conveying speed by the sheet discharge roller driving means so as to be equal to the document conveying speed by the sheet feeding roller driving means, or by controlling the sheet feeding roller driving means to discharge the sheet discharge roller driving means. By adjusting the document conveying speed by the paper feed roller driving means so as to be equal to the document conveying speed by the adjustment, the adjustment can be simplified.

According to the second invention of the present invention, a control parameter for controlling the document conveying speed by the discharge roller driving means so as to be equal to the document conveying speed by the paper feed roller driving means, and a parameter storage for storing the control parameters. And the parameter storage means is non-volatile, and controls the conveying speed of the document driven by the conveying roller based on the parameters of the parameter storing means in the actual document reading mode. No need for readjustment when restarting after turning off.

According to the third aspect of the present invention,
There are a plurality of document image reading speeds, and the document image reading speed is controlled by controlling the document conveying speed by the discharge roller driving means so as to be equal to the document conveying speed by the paper feed roller driving means according to each document image reading speed. Accuracy is improved.

According to a fourth aspect of the present invention,
It can be controlled by a measuring means for measuring the paper size in the original conveying direction in the actual original reading mode, a conveying speed control determining means for determining whether the conveying speed can be controlled by the size of the paper, and the conveying speed control determining means. If it is determined, it is checked whether or not it is necessary to control the conveyance speed when reading the image. If it is necessary to control the conveyance speed, after one series of image reading is completed, By controlling the reading mode, the maintainability is improved and fine adjustments with time are possible.

  As described above, according to the first aspect of the present invention, the adjustment is simplified by measuring and controlling the document conveying speed of the paper discharge roller without adjusting based on the image information by the special adjustment chart. Is possible.

  According to the second aspect of the present invention, the control parameter for controlling the document conveyance speed by the paper discharge roller driving means so as to be equal to the document conveyance speed by the paper feed roller driving means, and the control parameter are set in a non-volatile manner. By storing in the volatile memory, there is no need for readjustment when the apparatus is turned off and then restarted.

  According to the third aspect of the present invention, there are a plurality of document image reading speeds, and the discharge roller driving is performed so as to be equal to the document conveyance speed by the sheet feeding roller driving means according to each document image reading speed. By controlling the conveying speed of the document by the means, the reading accuracy is improved.

  According to the fourth aspect of the present invention, in the actual document reading mode, the measuring means for measuring the paper size in the document transport direction and the transport speed control determination for determining whether the transport speed can be controlled by the size of the paper. If it is determined that it is controllable by the control means and the transport speed control determination means, it is confirmed whether or not it is necessary to control the transport speed when reading the image, and if it is necessary to control the transport speed. After a series of image readings are completed, control is performed to the next reading mode, so that the maintainability is improved and fine adjustment with a change with time is possible.

  The best mode for carrying out the present invention will be described below with reference to the drawings based on the embodiments.

(First embodiment)
A first embodiment of the present invention will be described based on the electric block diagram of FIG.

  Reference numeral 1 denotes a paper feeding unit on which a document 2 is set. The document size can be freely set, but a standard document is used to execute the discharge roller conveyance speed control of the present invention. Reference numeral 3 denotes a paper feed roller, which picks up the originals 2 one by one from a plurality of originals stacked on the paper supply unit 1 and conveys them to the image reading position Y. Reference numeral 5 denotes a registration sensor, which detects whether or not the leading edge of the document 2 is on the registration roller 13. The registration sensor 5 is disposed at the position A. Reference numeral 6 denotes a paper feed sensor, which detects whether or not the document 2 starts reading and passes the paper feed roller 3. The paper feed sensor 6 is disposed at the position B. A paper discharge sensor 7 is disposed at position C and detects whether or not the paper discharge roller 8 is passing.

  An original reading unit 4 includes an image sensor 16, a lens (not shown), a lamp 15 for irradiating an original, a reflection mirror (not shown), and the like. The original 2 is conveyed and the original 2 is placed at the original irradiation position. When transported, the image of the document 2 is read. Reference numeral 28 denotes a reference white plate for performing white correction for image reading.

  Reference numeral 3 denotes a paper feed roller, and 10 denotes a paper feed roller drive circuit, which drives the paper feed roller 3. A paper discharge roller 8 and a paper discharge roller drive circuit 9 drive the paper discharge roller 8.

  Reference numeral 12 denotes a CPU circuit which operates the paper feed roller drive circuit 10 and the paper discharge roller drive circuit 9 based on the input of each sensor, sequence control by control, measurement of the document conveyance speed of the paper discharge roller 8, and paper discharge The roller driving circuit 9 is controlled to control the document conveying speed of the paper discharge roller 8.

  Next, the operation sequence of the present invention will be described with reference to FIGS. 2 (A), 2 (B), 3 (A), and 3 (B).

  FIG. 2A is a cross-sectional view showing the arrangement of each roller, sensor, and document.

  FIG. 2B shows the output of each sensor when the original is conveyed from the registration roller to the paper discharge stacker. The document is configured to be at “H” level when the document passes. FIG. 3A is a flowchart showing the operation of the first embodiment of the present invention. FIG. 3B is a flowchart showing the detailed operation of S3 of FIG.

  In FIG. 3A, first, the ADF is set to a document reading mode in which an actual document reading operation is performed or a conveyance speed adjustment mode for normal conveyance. This time, the conveyance speed adjustment mode is set (S301).

  Next, in order to start the conveyance speed adjustment by the paper discharge roller, it is necessary to set an adjustment document on the ADF. This is not necessary to print a special image, and can be adjusted for a document of a standard size. When it is confirmed that the originals are stacked, the paper supply driving circuit is activated to supply the originals and the paper supply rollers are driven (S302).

  From the next step (S303), the operation proceeds to the discharge roller conveyance control operation. In FIG. 3B, after the paper feed roller is driven and passes the sensor A, the sensor B rises when it passes the sensor B. The rising times tab of the sensors A and B are measured (S3-1).

  Based on the tab AB and the distance AB between the sensors A and B, the sheet feed conveyance speed Va = AB / tab is calculated (S3-2).

  Further, in order to discharge the original, the paper discharge driving circuit is activated to drive the paper discharge roller (S3-3).

  When the document is discharged and passes the sensor C, the output of the sensor C rises. The rise times tcb of sensors C and B are measured (S3-4).

  Generally, Tbc '= HB / Va + CH / Vb, where Vb is the conveyance speed of the discharge roller, HB is the distance between sensor B and the discharge roller, and CH is the distance between sensor C and the discharge roller. If the reference Tbc is when Vb = Va, then Tbc = (HB + CH) / Va. Vb is calculated by the following calculation formula (S3-5). That is, Vb = CH / (Tbc'-HB * Tab / AB).

  If Va> Vb, the paper discharge drive circuit is controlled to increase the speed and adjust to Va (S3-7, S3-8). If Va <Vb, the paper discharge drive circuit is controlled to slow down the speed and adjust to Va (S3-9).

  In this embodiment, the description has been made to control the document conveyance speed by the paper discharge roller on the assumption that the document conveyance speed by the paper feed roller becomes equal to the reading speed. Alternatively, the document conveyance speed by the sheet feeding roller may be controlled on the assumption that the speed is constant.

(Example 2)
A second embodiment of the present invention will be described with reference to FIG.

  In FIG. 9, reference numeral 17 denotes a paper discharge control memory. The paper discharge roller drive control parameter determined so that the document conveyance speed by the paper discharge roller 8 executed in the first embodiment is equal to the document reading speed by the paper supply roller 3. For temporary storage. The control parameter is a coefficient corresponding to Va / Vb.

  When the discharge roller driving source is constituted by a pulse motor, if the pulse / s when the conveyance speed by the discharge roller is driven by Vb is N, the conveyance speed of the discharge roller is set to Va. The paper discharge roller drive control is controlled by N × Va / Vb pulses / s.

  A paper feed control memory 27 temporarily stores paper feed roller drive control parameters determined so that the document transport speed by the paper feed roller 3 is equal to the document reading speed.

  Reference numeral 19 denotes an operator panel, which can be set such as an image reading mode and an adjustment mode for performing the discharge roller driving control and switching of the image reading mode.

  The operation of the second embodiment of the present invention will be described based on the flowchart of FIG.

  First, the adjustment mode is set to determine the discharge roller drive control parameter. The setting method is set by the operator panel 19 (S801).

  When a standard-size sheet for adjustment is loaded on the sheet feeding unit, sheet feeding is started (S802), and the sheet feeding roller conveyance speed Va 'is measured (S803).

  The paper feed roller drive control parameter (V / Va) is written in the paper feed control memory 27 so that Va 'is equal to the document reading speed V (S804).

  The paper feed roller drive circuit 10 is controlled based on the paper feed roller drive control parameter. After the paper feed roller transport speed Va 'is adjusted to Va (= V), the paper is transported and discharged in the ADF, and the transport speed Vb by the paper discharge roller 8 is calculated (S805).

  Further, a control parameter (Va / Vb) is written in the paper discharge control memory 17 so that the conveyance speed by the paper discharge roller 8 becomes the original reading speed Va (S806).

  In the document reading mode, the discharge roller drive circuit 9 and the feed roller drive circuit 10 are controlled with reference to the discharge roller drive control parameter from the discharge control memory 17 and the feed roller control parameter from the paper feed control memory 27. .

(Example 3)
The third embodiment of the present invention will be described with reference to FIG.

  In FIG. 6, reference numeral 17 denotes a memory A, and a discharge roller drive control parameter A determined so that the document conveyance speed by the discharge roller 8 executed in the first embodiment is equal to the document reading speed A by the sheet supply roller 3. For temporary storage.

  Reference numeral 18 denotes a memory B, which temporarily sets a discharge roller drive control parameter B determined so that the document transport speed by the paper discharge roller 8 executed in the first embodiment is equal to the document transport speed B by the paper feed roller 3. It is for storing.

  The operation of Embodiment 3 of the present invention will be described based on the flowchart of FIG.

  First, the adjustment mode is set to determine the discharge roller drive control parameter (S501).

  In order to determine the discharge roller drive control parameter A, the conveyance speed by the paper supply roller 3 is set to the original reading speed A. The setting method is set by the operator panel 19 (S502).

  When a standard size sheet for adjustment is loaded on the sheet feeding unit, sheet feeding is started (S503), and the sheet feeding roller conveyance speed VaA 'is measured (S504).

  The paper feed roller driving circuit 10 is controlled so that VaA 'becomes the original reading speed VaA. The paper is transported and discharged in the ADF, and the transport speed VbA by the paper discharge roller 8 is calculated (S505).

  Further, the control parameter A (VaA / VbA) is written into the memory A so that the conveyance speed VbA by the paper discharge roller 8 becomes the original reading speed VaA (S506).

  In the next step (S507), in order to determine the discharge roller drive control parameter B, the conveyance speed by the paper supply roller 3 is set to the original reading speed VaB.

  In S508 to S511, the same processing as S503 to S507 is performed. In S510, the conveyance speed VbB ′ by the paper feed roller 3 is calculated, and in S511, the control parameter B (VaB / VbB) is written in the memory B so as to become the original reading speed VbB. . At the time of document reading, the reading speed is set from the external I / F, so the discharge roller driving circuit 9 is controlled with reference to the discharge roller driving control parameter from the memory corresponding to the set document reading speed.

  In this embodiment, the document reading speed is two, but it may be higher. In the method for setting the original reading speed, the operator panel is used to set the original reading speed. However, when a fixed-size sheet for adjusting the number of the original reading speed is loaded on the paper feeding unit, each original reading speed is automatically set. The paper discharge roller drive control parameter may be determined according to the above.

Example 4
The operation of the fourth embodiment will be described with reference to FIG.

  First, when the document reading mode by ADF is started in S401, paper feeding is started (S402).

  Next, the paper discharge roller drive control parameters already written are read from the memory and referred to (S403).

  The discharge roller drive control parameter adjusted in the adjustment mode is written only when the original is read in the first original reading mode. Based on the control parameter referred to, the paper discharge roller drive circuit 9 is operated to control the transport speed of the paper discharge roller 8 (S404).

  When the document is fed, sensor A confirms the passing of the document. The size of the document in the conveyance direction is calculated by measuring the document passing time (S405).

  If the calculated size is an indefinite shape longer than the distance from the sensor C to the paper feed roller K, the transport speed of the paper discharge roller 8 cannot be measured, and the process ends (S406).

  If the paper size <CH, the paper discharge roller conveyance speed Vb of the first embodiment is measured (S407).

  It is confirmed whether or not the measured Vb is different from the discharge roller drive control parameter (S408).

  If they are not different, the process is terminated and the document image reading from the next ADF is also referred to the current discharge roller drive control parameter. If they are different, the paper discharge roller drive control parameter is updated (S409).

  This prevents variations in printing accuracy between pages due to changing the conveyance speed when reading a series of document images.

ADF section cross section and electrical block diagram for explaining the first embodiment of the present invention ADF sectional view for explaining the operation of the first embodiment of the present invention Each sensor output diagram of Example 1 of the present invention The flowchart explaining operation | movement of Example 1 of this invention. 7 is a flowchart for explaining a discharge roller conveyance speed measurement operation according to the first exemplary embodiment of the present invention. The flowchart explaining operation | movement of Example 4 of this invention. The flowchart explaining operation | movement of Example 3 of this invention. ADF section cross section and electric block diagram for explaining a third embodiment of the present invention Cross-sectional view of an image reading apparatus explaining a conventional example Special chart for adjusting the conveyance speed with images in the conventional example The flowchart explaining operation | movement of Example 2 of this invention. ADF section cross section and electric block diagram for explaining a second embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feed part 2 Document 3 Feed roller 4 Document reading unit 5 Registration sensor 6 Paper feed sensor 7 Paper discharge sensor 8 Paper discharge roller 9 Paper discharge roller drive circuit 10 Paper feed roller drive circuit 12 CPU circuit 13 Registration roller 14 Pickup roller 15 Document Lamp 16 for illumination Image sensor 17 Paper discharge control memory (memory A)
18 Memory B
19 Operator panel 22 Automatic paper feeder (ADF)
24 Feed motor 25 Belt 26 Feed motor shaft 27 Feed control memory 28 Standard white plate

Claims (4)

  An image reading apparatus having an automatic paper feeder that reads a document image line by line while sequentially feeding a plurality of sheet-like documents and transporting them to a predetermined reading position, and a document reading mode for reading an actual document An adjustment mode in which adjustment is performed before reading, and in the adjustment mode, a paper feed roller for picking up a document for each sheet, a paper feed roller driving means for driving the paper feed roller, and the paper feed roller drive means include: The document feeding speed is controlled so as to be the document reading speed, and the sheet feeding roller conveys the fed sheet document to the reading position, and discharges the sheet after passing the document reading position and the sheet discharging roller. A paper discharge roller driving means for driving, a first document detection means installed at a predetermined position upstream of the paper feed roller to detect the presence of a document, and between the paper feed roller and the transport roller Second document detection means for detecting a document placed at a predetermined location and transported from a paper feed roller, and a third document detection for detecting a document placed at a predetermined location downstream of the transport roller and discharged from the transport roller And a measuring means for measuring the time of passage of the original by each of the original detecting means, and the passage time when the original transport speed is the original reading speed is set as a reference time, and the reference time and the measurement time are Compare and control the paper discharge roller driving means to control the document conveyance speed by the paper discharge roller driving means so as to be equal to the document conveyance speed by the paper feed roller driving means, or An image reading apparatus that controls the document conveyance speed by the paper feed roller driving means so as to be equal to the conveyance speed of the document by the paper discharge roller driving means.   A first control parameter for controlling the document conveyance speed by the paper feed roller driving means so that the document conveyance speed by the paper feed roller driving means becomes equal to the document reading speed, and a first control parameter for storing the first control parameter. Parameter storage means, a second control parameter for controlling the document conveyance speed by the discharge roller driving means so as to be equal to the document conveyance speed by the discharge roller driving means, and the second control parameter. Second parameter storage means, and the first parameter storage means and the second parameter storage means are nonvolatile, and in the actual document reading mode, the first parameter storage means or the second parameter storage means 2. The image reading apparatus according to claim 1, wherein the conveyance speed of the document driven by the conveyance roller is controlled based on parameters of the parameter storage means. .   A plurality of document image reading speeds are provided, and the document transport speed by the discharge roller driving unit is controlled so as to be equal to the document transport speed by the paper feed roller driving unit according to each document image reading speed. An image reading apparatus.   In an actual document reading mode, a measurement unit that measures the paper size in the document conveyance direction, a conveyance speed control determination unit that determines whether the conveyance speed can be controlled by the size of the sheet, and a conveyance speed control determination unit If it is determined that control is possible, it is checked whether or not the conveyance speed needs to be controlled when reading the image. If there is a need to control the conveyance speed, a series of image reading is completed. The image reading apparatus according to claim 1, wherein after that, the next reading mode is controlled.

Images