JP2005150947A - Document reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a document reading apparatus capable of adjusting a reference time index when an actual time index required for a time from the detection of the head end of a document until the detection of the tail end thereof does not match a reference time index due to the paper slippage or the like of a roller provided on a document transfer path, thereby eliminating the necessity of the maintenance of the roller of the transfer path as much as possible. <P>SOLUTION: A first document position detecting sensor DSS detects the head end and tail end of the document. A control apparatus 42 measures an actual time index between the head end detection of the document and tail end detection by the sensor DSS. The control apparatus 42 determines the length of the document in a transferring direction on the basis of the comparison of the actual time index and the reference time index. If the actual time index does not match the reference time index, the control apparatus 42 corrects the reference time index. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a copying machine, a facsimile machine, a scanner, and a document reading apparatus provided in a multifunction machine thereof.

2. Description of the Related Art In recent years, a copying machine or a facsimile with a copying function provided with a flatbed scanner (FBS) that reads a stationary document placed on a document placement plate and a multiple document automatic reading unit (ADF) that automatically reads a plurality of documents. The apparatus is becoming mainstream as a document reading apparatus. In these document reading apparatuses, a technique for detecting the length in the document feeding direction (sub-scanning direction) has been proposed. For example, in Patent Document 1, a sensor is provided for detecting the leading edge and the trailing edge of a document when the document is supplied to a conveyance path. When copying using a plurality of document automatic reading units, when a document is placed on a document table and a start key is operated, the documents are supplied while being separated one by one. Then, in the conveyance path to which the document is supplied, the leading edge and the trailing edge are detected by a sensor that detects the leading edge and the trailing edge of the document. Then, during the period from the leading edge detection to the trailing edge detection of the document, the number of rotations of the motor that drives the roller for conveying the document is counted. Then, whether or not this count number matches the set count number stored in advance in the memory is determined at the time of detecting the trailing edge of the document, and if it matches, the length of the document in the feed direction can be determined. I have to. In Patent Document 2, the length of the document in the feeding direction can be determined based on the roller rotation time from the detection of the leading edge of the document to the detection of the trailing edge.
Japanese Patent Laid-Open No. 2002-60089 JP 2000-128387 A (paragraph “0058”)

  However, when the sensor for detecting the leading edge and the trailing edge of the document performs the leading edge detection and the trailing edge detection, the count number and the setting are set in Patent Document 1 due to paper slippage of a roller provided in the conveyance path. The count numbers may not match. Further, in Patent Document 2, there are cases where the roller rotation time becomes long and the document feed direction length cannot be determined correctly. In such a case, an error occurs, and it is therefore necessary for the document reading apparatus to perform maintenance work on the rollers in the conveyance path.

  An object of the present invention is to provide a reference time index when the real time index required from the leading edge detection to the trailing edge detection of a document does not match the reference time index due to a paper slip of a roller provided in the document conveyance path. Thus, it is possible to provide a document reading apparatus that can minimize the maintenance of the rollers in the conveyance path.

  In order to solve the above-mentioned problems, the invention described in claim 1 is a detection means for detecting a leading edge and a trailing edge of a document, and measures a real time index between the detection of the leading edge and the trailing edge of the document of the detection means. Based on a comparison between the measurement means for storing, a storage means for storing in advance a reference time index required for the document to pass through the detection means, and a comparison between the real time index and the reference time index stored in the storage means. An original reading apparatus provided with a determining means for determining a length in a feeding direction, further comprising a correcting means for correcting the reference time index when the real time index does not coincide with the reference time index. The gist of the reading device is as follows.

  According to a second aspect of the present invention, there is provided a detecting means for detecting the leading edge and the trailing edge of the document, a measuring means for measuring a real time index between the leading edge detection and the trailing edge detection of the detecting means, and the detecting means for the document. Storage means for preliminarily storing a reference time index required to pass the document, and determination means for determining the length of the document feed direction based on a comparison between the real time index and the reference time index stored in the storage means An original reading apparatus comprising: a correcting unit that corrects the reference time index when the number of times that the real time index does not match the reference time index exceeds a predetermined number. It is a summary.

  According to a third aspect of the present invention, there is provided a detecting means for detecting the leading edge and the trailing edge of the document, a measuring means for measuring a real time index between the leading edge detection and the trailing edge detection of the detecting means, and the detecting means for the document. Storage means for preliminarily storing a reference time index required to pass the document, and determination means for determining the length of the document feed direction based on a comparison between the real time index and the reference time index stored in the storage means The gist of the original reading apparatus includes a reference time index correcting means for correcting the reference time index.

  According to the first to third aspects of the present invention, the real time index required between the leading edge detection and the trailing edge detection of the document due to a paper slip of a roller provided in the document conveyance path is the reference time index. If there is a discrepancy, the reference time index can be adjusted. As a result, there is an effect that it is possible to minimize the maintenance of the rollers in the conveyance path.

According to the first aspect of the present invention, when the real time index does not coincide with the reference time index, the above effect can be realized by correcting the reference time index by the correcting means.
According to the second aspect of the present invention, when the number of times that the real time index does not match the reference time index exceeds a predetermined number, the effect is realized by correcting the reference time index by the correcting means. Can do. According to the second aspect of the present invention, when the paper slip happens to occur and the paper slip disappears thereafter, the reference time index is not corrected.

  According to the invention of claim 3, the above-mentioned effect can be realized by correcting the reference time index by the reference time index correcting means.

(First embodiment)
Hereinafter, an embodiment in which the image forming apparatus of the present invention is embodied in a facsimile machine with a copying function (hereinafter referred to as a multifunction machine) will be described with reference to FIGS.

  As shown in FIG. 2, on the upper part of the multifunction machine 10 serving as a document reading device, a document feeder 11 for continuously transporting a plurality of documents in order to continuously transport the documents and read both front and back surfaces. A document placing portion 12 for reading a still image and a document reading mechanism portion 13 having a document reading mechanism are installed. Also, a well-known recording paper supply unit, a recording unit, and a recording paper discharge unit (not shown) are installed at the lower part of the multifunction machine 10.

  The document feeder 11 includes a document table 14 on which a plurality of documents before reading are placed in a stacked state, and a document discharge table 15 on which the documents after reading are placed in a stacked state. The document feeder 11 also includes an openable and closable shutter 16 that contacts the front ends of a plurality of documents placed on the document table 14 and a plurality of sheets whose front ends contact the closed shutter 16. A pickup roller 17 is provided that contacts the uppermost original document and conveys it forward. The leading edge of the document refers to an end on the document feeding direction side, and the trailing edge refers to an end on the counter feeding direction side. Further, the document feeding unit 11 includes a separation roller 18 and a separation pad 18a that separate the documents conveyed by the pickup roller 17 through the shutter 16 one by one and feed them forward. The conveyance path of the present embodiment is configured such that one path extends from the separation roller 18 to the document discharge port to the document discharge table 15. The separation roller 18 corresponds to a document feeding roller.

  As shown in FIGS. 1 and 2, the document feeding unit 11 sequentially includes a registration roller 19, a first feeding roller 20, a second feeding roller 21, a surface reading roller 22, a first reading roller 22, and a first reading roller 22. 3 feed rollers 23, a back surface reading roller 24, and a fourth feed roller 25. The registration roller 19, the first feeding roller 20, the second feeding roller 21, the third feeding roller 23, and the fourth feeding roller 25 include idle rollers 19a, 20a, 21a, 23a, and 25a, respectively. Each roller 17-25 is operatively connected to one step motor 26 (shown in FIG. 3). The separation roller 18 and the registration roller 19 are operatively connected to a step motor 26 via electromagnetic clutches 27 and 28 (shown in FIG. 3), respectively. Further, the document feeding unit 11 includes a contact image sensor 29 disposed to face the back surface reading roller 24. The contact image sensor 29 corresponds to a reading unit.

  As shown in FIG. 1, a document size detection sensor DLS for detecting the size in the main scanning direction based on the width of the document placed on the document table 14 is provided on the document table 14 of the document feeder 11. Is provided. Further, a document presence / absence detection sensor DS1 for detecting the presence / absence of a document in contact with the shutter 16 is provided between the pickup roller 17 and the shutter 16. A first document position detection sensor DSS for detecting the position of the conveyed document is provided near the separation roller 18 between the separation roller 18 and the registration roller 19. In the present embodiment, the first document position detection sensor DSS corresponds to detection means for detecting the leading edge and the trailing edge of the document according to the present invention. In addition, a registration sensor DRS is provided in the vicinity of the registration roller 19 for detecting that the leading edge of the document has come into contact with the registration roller 19. A second document position detection sensor DS2 that detects the position of the document is provided near the second feed roller 21 between the first feed roller 20 and the second feed roller 21. Further, a third document position detection sensor DS 3 for detecting the position of the document is provided between the third feeding roller 23 and the back surface reading roller 24. The transport path cover K of the multifunction device 10 is disposed so as to cover the rollers, the various sensors, and the contact image sensor 29, and is detachably attached to the upper case UK of the multifunction device 10.

  As shown in FIG. 2, the document placement section 12 includes a transparent document placement plate 30 for placing a document on the upper surface, and a presser disposed on the document placement plate 30 so as to be openable and closable. And a lid 31. The document table 14 and the document discharge table 15 of the document feeding unit 11 are disposed on the presser lid 31 of the document placement unit 12.

  As shown in FIGS. 1 and 2, the document reading mechanism unit 13 constituting the reading unit includes a light-transmitting plate 32 disposed opposite to the surface reading roller 22 of the document feeding unit 11, and the light-transmitting plate. And a light source 33 for irradiating light to a document passing over the document 32 or a document placed on the document placing plate 30. The document reading mechanism unit 13 moves the first mirror 34, the second mirror 35, and the third mirror 36 that change the optical path of the reflected light from the document, and the light source 33 and the first to third mirrors 34 to 36. And a well-known moving mechanism (not shown). Further, the document reading mechanism unit 13 reads the image of the document based on the condensing lens 37 for converging the light from the third mirror 36 and the light incident through the condensing lens 37 and the image signal of the read document. And an image pickup device (CCD) 38 for outputting.

  The light source 33 and the first mirror 34 are supported by a first carriage 39 that is moved and arranged in the sub-scanning direction by a moving mechanism. The second and third mirrors 35 and 36 are supported by a second carriage 40 that is similarly moved and arranged in the sub-scanning direction. The first carriage 39 is moved at a moving speed twice that of the second carriage 40 by the moving mechanism. Then, the first carriage 39 and the second carriage 40 are moved and arranged from the standby position P1 set almost at the center of the movement range to the reading position P2 facing directly below the translucent plate 32. Further, a position P3 that is located immediately below the end on the document feeder 11 side of the document placing plate 30 and a position P4 that is located directly below the end on the opposite side of the document placing plate 30 are located. Moved.

  The document feeding unit 11 and the document reading mechanism unit 13 configured as described above constitute an automatic document reading device (ADF), and the first and second carriages 39 and 40 are arranged at the reading position P2, A document passing over the translucent plate 32 is read. The document placing section 12 and the document reading mechanism section 13 constitute a flat bed scanner (FBS), and the document placing plate is moved by moving the first and second carriages 39 and 40 from the position P3 to the position P4. The original placed on 30 is read.

Next, the electrical configuration of the present embodiment will be described.
As shown in FIG. 3, the multifunction machine 10 includes a step motor 26, a separation roller based on signals input from the sensors DLS, DS 1, DSS, DRS, DS 2, DS 3 and a document reading start button 41. A control device 42 that controls the clutch 27, the registration roller clutch 28, the contact image sensor 29, and the image sensor 38 is provided. Further, the control device 42 stops the step motor 26 by a signal input from the stop button 45. The control device 42 includes an MPU, ROM, RAM, and the like, and also includes a readable / writable storage unit 43 for storing the size of the document in the sub-scanning direction and the main scanning direction. In the present embodiment, the storage unit 43 is configured by EEPR0M. Further, the control device 42 is configured to count the number of steps of the step motor 26 in order to count the amount of the document that has been fed from the separation roller 18, and a count area (not shown) of the storage unit 43. No) is stored in the count. In the set count number storage area of the storage unit 43, a set count number CR is stored in advance as a reference time index for each standard size, and when the size of the document in the horizontal direction is determined in the flowchart described later. Uniquely, one set count number CR corresponding to the size in the horizontal direction is read out. The control device 42 corresponds to determination means, measurement means, and correction means. The separation roller 18 corresponds to a document conveying roller. The storage unit 43 corresponds to storage means.

  A display device 44 as a display means is electrically connected to the control device 42. The display device 44 is composed of an LCD (liquid crystal display device), and performs various displays by display control of the control device 42.

  Based on the detection signals of the various sensors, the control device 42 feeds a plurality of documents placed on the document table 14 one by one to the conveyance path and conveys them along the conveyance path. 38. The contact image sensor 29 is used to read the front and back surfaces of the document, and reading control for sequentially discharging the read document to the document discharge table 15 is executed.

  Although not shown in FIG. 3, the control device 42 includes a recording unit that records received image data and image data read by the reading unit, a recording paper supply unit that supplies recording paper to the recording unit, and a facsimile device. A modem, an NCU, a codec, and the like are connected, but since these are not directly related to the present invention, description thereof is omitted.

  Next, the processing operation of the multifunction machine 10 will be described using the flowchart shown in FIG. FIG. 4 is a flowchart of the document size determination process executed by the MPU of the control device 42 based on the control program stored in the ROM. The following S represents a step.

  When the document is placed on the document table 14 and the start button 41 is operated, the rollers such as the separation roller 18 are driven by the step motor 26 by the step motor 26, and one document on the document table 14 is moved. Driven in the feed direction and supplied to the transport path. When the leading edge of the document is detected by the first document position detection sensor DSS in S10, in S20, the control device 42 determines the document lateral direction (document feeding direction) based on the detection signal from the document size detection sensor DLS. Defines the size (standard size) in the direction orthogonal to (main scanning direction). In S30, the control device 42 counts the number of steps of the step motor 26 after the leading edge of the document is detected (S30). The count number at this time is represented by C.

  In S40, the control device 42 reads the set count number CR uniquely determined by the determination of the lateral size of the original in S30 from the set count number storage area of the storage unit 43, and the count number C is the set count number. It is determined whether or not the CR has been exceeded. If the count number C is less than the set count number CR, the process returns to S30. If the count number C is equal to or greater than the set count number CR, in S50, the control device 42 determines whether or not the document trailing edge detection is performed by the first document position detection sensor DSS. If the trailing edge of the document is not detected, the control device 42 returns to S30, and counts the number of steps of the step motor 26 in S30.

  When the trailing edge of the document is detected in S50, the controller 42 calculates a difference ΔC between the count number C and the set count number CR in S60, and resets the count number C to 0 in S70. Here, the set count number CR from the leading edge detection to the trailing edge detection corresponds to the real time index. In the next S80, it is determined whether or not the difference ΔC is equal to or smaller than a preset allowable value Ck. If the difference ΔC exceeds the preset allowable value Ck, the control device 42 performs error processing in S110. In the present embodiment, the display device 44 displays an error, and the document The step motor 26 is stopped to stop the conveyance of the motor.

  In S80, if the difference ΔC is equal to or smaller than the preset allowable value Ck, in the update process of S90, the control device 42 stores the setting stored in the set count number storage area in order to correct the set count number CR. A value obtained by adding the difference ΔC to the count number CR is updated as a new set count number CR and stored in the set count number storage area. When updating the set count number CR, instead of the difference ΔC, a constant such as an allowable value Ck or a test value obtained by performing a test is added as an addition value, or a plurality of differences ΔC calculated at each time are added. May be stored in the storage unit 43 as a history, and an average value of the plurality of differences ΔC may be added as an addition value.

  In next step S100, the control device 42 determines the size of the document (size in the document feed direction) based on the count number C, and ends the flowchart. The determination of the size in S100 corresponds to determination of the length of the document in the feed direction.

  According to the present embodiment, when the original is transported, a paper slip occurs on the separation roller 18, and when the count number C of the step number of the step motor 26 is equal to or greater than the set count number CR, the difference ΔC is equal to or less than the allowable value Ck. In this case, the difference ΔC is added to the set count number CR to be updated. For this reason, while the document can be updated, the conveyance of the document is not stopped, so that it is possible to minimize the maintenance of the rollers on the conveyance path.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. Since the hardware configuration of the second embodiment is substantially the same as that of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and different points will be mainly described. FIG. 5 is a flowchart of the document size determination process executed by the MPU of the control device 42. The same steps as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the second embodiment, if the difference ΔC is equal to or smaller than the preset allowable value Ck in S80, the controller 42 counts the number of times that the difference ΔC is equal to or smaller than the allowable value Ck in S82. The number of counts at this time is represented by N. In next step S84, the control device 42 determines whether or not the count number N has reached a preset number Na as a predetermined number of times. If the count number N has not reached the set number Na in S84, the control device 42 jumps to S100. If the count number N has reached the set number Na in S84, the control device 42 updates the set count number CR in S90. When the update processing of the set count number CR in S90 is completed, the control device 42 resets the count number N to 0 in S95.

  Now, according to the second embodiment, when the original is transported, a paper slip occurs on the separation roller 18, and when the step count number C is equal to or greater than the set count number CR, the difference ΔC is equal to or less than the allowable value Ck. In addition, the number of times that the difference ΔC has become equal to or less than the allowable value Ck is counted. Then, when the count number N reaches the set number Na, the set count number CR is updated. As a result, when the paper slip happens to occur and no paper slip occurs after that, the update processing of the set count number CR is not performed when the paper slip happens. When the count number N reaches the set number Na, the set count number CR is updated. In this case, the conveyance of the document is not stopped, and the maintenance of the rollers on the conveyance path is unnecessary. It can be.

(Third embodiment)
Next, a third embodiment will be described with reference to FIGS. In the third embodiment, a reference time index correction key group 50 as reference time index correction means is connected to the control device 42. The reference time index correction key group 50 includes a numeric keypad and an input mode setting key for correcting and inputting a reference time index. When the input mode key is input, a mode for correcting and inputting the reference time index is entered. By entering the numeric keypad of the reference time index correction key group 50 in this mode, the set count number CR that is the reference time index is set. The input value can be input, and the input value is stored in the set count number storage area of the storage unit 43.

  A flowchart of document size determination processing in the third embodiment is shown in FIG. As shown in the figure, in the flowchart, the process of S90A is performed instead of S90 of the first embodiment. If the difference ΔC is less than or equal to the preset allowable value Ck in S80, a display prompting the user to reset the set count number CR is displayed on the screen of the display device 44 in S90A, and the process proceeds to S100.

  According to this display, the operator inputs the reference time index correction key group 50 while the conveyance of the original document of the multi-function peripheral 10 is stopped, and the value of the set count number CR is an arbitrary value relative to the previous value. Set the value so that the value is added. Instead of this arbitrary value, a value obtained by a test or the like may be described in advance in a manual or the like and recommended, and the operator may input this value. With this input, the control device 42 stores the new set count number CR in the set count number storage area of the storage unit 43. When an input operation is performed using the reference time index correction key group 50, the control device 42 displays the set count number CR, which is the current value, on the display device 44, and prompts input by referring to this value. You may do it.

  After the set count number CR is newly set, in the flowchart of the document size determination process in FIG. 6, the control device 42 performs the process in S40 based on the reset set count number CR.

  According to the third embodiment, when the paper slips on the roller, the set count number CR can be reset by the reference time index correction key group 50 if the allowable value Ck or less. For this reason, the conveyance of the document is not stopped, and the maintenance of the rollers on the conveyance path can be made as small as possible.

  In each of the above embodiments, the count number C is used as the real time index, and the set count number CR is used as the reference time index. Instead, the real time index may be set as the time from the leading edge detection to the trailing edge detection of the document, and the reference time index may be set as the target time.

  In the first embodiment and the second embodiment, both sides of the document are read, but may be embodied in a document reading apparatus that reads only one side. Further, the present invention may be embodied in a copying machine or a facsimile machine instead of a multifunction machine.

FIG. 3 is a longitudinal sectional view illustrating a document feeding unit and a reading unit in the multifunction machine according to the first embodiment. FIG. 3 is a longitudinal sectional view showing an upper part of the multifunction machine. FIG. 2 is a block diagram illustrating an electrical configuration of the multifunction machine. 6 is a flowchart of document size determination processing executed by the MPU of the control device according to the first embodiment. 10 is a flowchart of document size determination processing executed by the MPU of the control device of the control device according to the second embodiment. 10 is a flowchart of document size determination processing executed by the MPU of the control device of the control device according to the third embodiment.

Explanation of symbols

DSS: First document position detection sensor (detection means)
DESCRIPTION OF SYMBOLS 10 ... Multifunction machine 18 ... Separation roller 42 ... Control apparatus (measuring means, correction means, determination means)
43 ... Storage section (storage means)
50: Reference time index correction key group (reference time index correction means)

Claims (3)

Detection means for detecting the leading edge and trailing edge of the document, measurement means for measuring a real time index between the detection of the leading edge and the trailing edge of the detection means, and a reference time required for the document to pass through the detection means In a document reading apparatus provided with a storage unit that stores an index in advance, and a determination unit that determines a length in a document feeding direction based on a comparison between the real time index and a reference time index stored in the storage unit, An original reading apparatus, comprising: a correcting unit that corrects the reference time index when the real time index does not match the reference time index. Detection means for detecting the leading edge and trailing edge of the document, measurement means for measuring a real time index between the detection of the leading edge and the trailing edge of the detection means, and a reference time required for the document to pass through the detection means In a document reading apparatus provided with a storage unit that stores an index in advance, and a determination unit that determines a length in a document feeding direction based on a comparison between the real time index and a reference time index stored in the storage unit, An original reading apparatus, comprising: a correcting unit that corrects the reference time index when the number of times the real time index does not match the reference time index exceeds a predetermined number. Detection means for detecting the leading edge and trailing edge of the document, measurement means for measuring a real time index between the detection of the leading edge and the trailing edge of the detection means, and a reference time required for the document to pass through the detection means In a document reading apparatus provided with a storage unit that stores an index in advance, and a determination unit that determines a length in a document feeding direction based on a comparison between the real time index and a reference time index stored in the storage unit, An original reading apparatus comprising reference time index correcting means for correcting the reference time index.

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