JP2015128243A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader for improving precision of skew correction on flexible and inflexible documents.SOLUTION: An image reader 1 includes: an image reading section 4 consisting of CIS; a document transportation path 3; and document feeding means which consists of various rollers 6, 8 and 9 for transporting a document. A tip of the document which is transported along the document transportation path is made abut on a side of a housing 11 of the image reading section in front of a reading position, is once stopped and a skew is corrected by arranging tip positions of the documents. Abutting with the housing is cancelled and the document is transported through the document transportation path to perform reading. Abutting and cancelling of the document to the housing are performed by displacing the image reading section to the document transportation path or by changing the transportation height of the document by a transportation guide.

Description

  The present invention relates to an image reading apparatus, and more particularly to an image reading apparatus provided with an automatic document conveyance mechanism.

  2. Description of the Related Art Conventionally, an image reading apparatus such as a digital copying machine, a facsimile machine, or an image scanner is provided with a document conveying device that feeds a plurality of documents one by one and automatically conveys them to a reading position. The normal document feeder is provided with a function for correcting document skew.

  As the skew correction mechanism of the document feeder, the leading edge of the document fed from the document tray is abutted against the nip portion of the stopped registration roller, and after correcting the skew, the registration roller is rotated to bring the document to the reading position. What is conveyed is known (see, for example, Patent Document 1). In this case, the transport roller is further rotated with the leading end abutted against the stopped registration roller, and the document is fed out to form a loop of the document in the space of the transport path upstream of the registration roller. Aligned.

  Recently, an image reading process may be performed on a plastic or cardboard laminate or a resin or metal card such as a credit card, a cash card, various membership cards or certificates. Conveying such a hard and inflexible document with a document conveying device having a conventional structure may cause the conveyance itself to be impossible, or the document may be deformed or damaged, and reading may be hindered.

  A flexible original such as plain paper and an inflexible original such as a resin card are fed from separate paper feeding units, and the inflexible original is linear until it is discharged from the paper feed through the reading unit. Although a method for conveying the path is also conceivable, the configuration of the entire apparatus becomes complicated and handling of the original document becomes troublesome. Therefore, the inflexible card document conveyed from the document tray is bent by being guided from the first guide member for conveying the flexible sheet document onto the second guide member positioned below the first guide member. An original reading apparatus that can be conveyed toward the platen without any problem has been proposed (see, for example, Patent Document 2).

  On the other hand, resin cards such as credit cards and cash cards are embossed with letters and numbers on the surface, and there are many irregularities on the surface due to the built-in microchip, so they cannot be conveyed straight and skewed. May occur. In order to solve this problem, a part of the document transport path is composed of an upper surface guide and a lower surface guide, and the lower surface guide is provided with a pair of side surface guides for defining the positions of both side surfaces of the card document, 2. Description of the Related Art There is known a sheet conveying apparatus that is provided with an upwardly convex curved surface so as to define an upper surface position of a plain paper document together with an upper surface guide (see, for example, Patent Document 3).

JP 2012-240806 A JP 2012-15777 A JP 2012-41122 A

  However, when conveying an inflexible document such as a hard card, the apparatus described in Patent Document 3 must set the width between the side guides to match the card width, and the usable card width is limited. There is a risk of it. Further, if the width between the side guides can be adjusted, even if a slight backlash occurs between the cards, it is transported in an inclined manner, so that it is difficult to accurately correct the skew.

  In addition, in the apparatus described in Patent Document 1, when skew correction is performed on a flexible document such as plain paper by forming a loop with a registration roller, if the conveyance path from the registration roller to the document reading position is long, the document is again returned along the way. There is a risk of causing skew. Further, the leading edge of the document may enter the nip portion of the resist roller that is stopped, and the skew may not be corrected with high accuracy. In particular, when skew correction of an inflexible document is performed with a registration roller, there is a high possibility that the leading edge of the document is pushed into the nip portion of the stopped registration roller.

  Accordingly, the present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide an image reading apparatus capable of improving the accuracy of skew correction even for a flexible or inflexible document. Is to provide.

An image reading apparatus according to the present invention includes an image reading unit including a reading unit that reads an image of a document and a housing that holds the reading unit, a document conveyance path having a document reading position, and a document along the document conveyance path. A document feeding means for conveying, a moving means for relatively moving the document conveying path and the housing, and a control means for controlling the document feeding means and the moving means,
The control means temporarily stops the document conveyed along the document conveyance path by bringing the leading end of the document into contact with the housing before the reading position, and then releasing the contact with the housing and passing through the reading position. In this way, the document conveying path is conveyed.

  Since the skew of the document can be corrected by bringing the leading edge of the document being conveyed into contact with the housing of the image reading unit in this way, the skew correction position and the image reading position can be set very short. In addition, since the document skew correction and image reading are performed by the same image reading unit, no other document conveying member or component is interposed between the skew correction position and the image reading position. Therefore, the skew correction accuracy of the document is greatly improved.

  Further, by performing skew correction of the document in the housing of the image reading unit, a registration roller and a side guide of the document that are used for skew correction in the prior art are not required. Further, the position of the leading edge of the document abutting against it can be clearly recognized by the housing of the image reading unit, so that it is not necessary to provide a separate sensor for detecting the leading edge of the document. As a result, the number of parts can be reduced to simplify the configuration of the apparatus, and the entire apparatus can be saved in space, reduced in size, and reduced in cost.

  Further, when an inflexible document such as a resin or metal card is read, skew correction can be performed without restricting the position of the side surface by a guide member or the like, so that the width of the usable document is not limited. Accordingly, it is possible to read originals having various width dimensions with one apparatus, and to provide a versatile image reading apparatus.

  In one embodiment, the housing of the image reading unit is provided so as to be displaceable between a first position where the document can pass through the document transport path and a second position where the leading edge of the document can abut. Accordingly, it is not necessary to provide new parts or components for skew correction in the document conveyance path, and in addition to the above-described effects, the configuration of the document conveyance path can be particularly simplified.

  In this case, in an embodiment, the housing is configured to move up and down with respect to the document conveyance path, and is thereby displaceable between the first position and the second position. Such displacement of the housing can be realized by a relatively simple configuration without adding so many parts.

  In another embodiment, the housing is configured to be tilted about an axis perpendicular to the conveyance direction with respect to the document conveyance path, thereby being displaceable between the first position and the second position. . Such a displacement of the housing is also realized by a relatively simple configuration without adding so many parts.

  In another embodiment, the document transport path includes a first position where the leading edge of the document transported by the document feeding means abuts the housing, and the contact between the leading edge of the document and the housing is released. It is provided so as to be displaceable between a second position where it can be conveyed to the document reading position. As a result, the reading height of the image reading unit and the document is fixed, so that in addition to the above-described effects, the image reading can be performed more stably.

  In this case, in one embodiment, the document transport path includes a guide member capable of changing the document transport height so as to change the document feed direction between the first position and the second position. Such a guide member can be realized with a relatively simple configuration without adding so many parts.

  In one embodiment, the reading unit includes a lighting device that illuminates the document surface, a light receiving sensor, and a contact image sensor (CIS) that includes a rod lens array that focuses reflected light from the document surface on the light receiving sensor. ). Thereby, the whole apparatus can be further downsized. Further, when the housing of the image reading unit is displaced, the driving and driving mechanism can be simplified.

  In another embodiment, the image reading unit includes a first image reading unit having a reading unit that reads a document conveyed on the document conveyance path from above, and the image reading device includes a reading unit that reads the document from below. A second image reading unit is further provided. Thereby, both the front and back sides of the document can be read simultaneously.

  In this case, in one embodiment, the reading means of the first and second image reading units respectively form an illumination device that illuminates the document surface, a light receiving sensor, and reflected light from the document surface on the light receiving sensor. The illumination device of the reading means of the first and second image reading units is arranged upstream of the document conveyance path with respect to the rod lens array, and the first and second image reading units The optical axes of the rod lens array of the reading means are arranged at different positions along the document conveyance path.

  In general, in order to read a document stably and clearly with CIS, it is preferable that the document surface passes through a reading position at a predetermined reading speed. By disposing the CIS illumination device on the upstream side of the rod lens array, the length from the stop position of the document to the reading position can be set longer. It is relatively easy to accelerate to obtain a desired reading speed at the reading position.

  In another embodiment, the document transport path includes a first document transport path for transporting a flexible document and a second document transport path for transporting an inflexible document. Inflexible documents require a document transport path to be provided in a straight line and are often of a small card size. Thus, when a document transport path is provided separately, a common document transport path is provided. As a result, the configuration of the entire apparatus and the handling of the original can be simplified.

  In this case, in one embodiment, the document conveyance direction of the first document conveyance path passing through the reading position and the document conveyance direction of the second document conveyance path are provided in opposite directions. Since a flexible document can be bent and conveyed in a folding direction with respect to an inflexible document conveyed linearly, the first document conveyance path and the second document conveyance path are provided in opposite directions. Thus, the overall size of the apparatus can be reduced.

1 is a cross-sectional view schematically showing a basic configuration of an image reading apparatus according to the present invention. FIG. 3 is enlarged sectional views sequentially illustrating operations of the image reading apparatus in FIG. 1. FIG. 3 is enlarged sectional views sequentially illustrating operations of the image reading apparatus in FIG. 1. FIG. 3 is enlarged sectional views sequentially illustrating operations of the image reading apparatus in FIG. 1. FIG. 3 is enlarged sectional views sequentially illustrating operations of the image reading apparatus in FIG. 1. It is sectional drawing which shows the 1st embodiment of the image reading apparatus of this invention provided with the automatic document feeding function. It is an expanded sectional view which shows operation of the 1st embodiment of Drawing 3 in order. It is an expanded sectional view which shows operation of the 1st embodiment of Drawing 3 in order. It is an expanded sectional view which shows operation of the 1st embodiment of Drawing 3 in order. It is an expanded sectional view which shows operation of the 1st embodiment of Drawing 3 in order. It is an expanded sectional view which shows operation of the 2nd embodiment of Drawing 3 in order. It is an expanded sectional view which shows operation of the 2nd embodiment of Drawing 3 in order. It is an expanded sectional view which shows operation of the 2nd embodiment of Drawing 3 in order. It is an expanded sectional view which shows operation of the 2nd embodiment of Drawing 3 in order. It is an expanded sectional view which shows operation of the 3rd embodiment of Drawing 3 in order. It is an expanded sectional view which shows operation of the 3rd embodiment of Drawing 3 in order. It is an expanded sectional view which shows the 4th embodiment of FIG.

  Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings. In the accompanying drawings, the same or similar components are denoted by the same or similar reference numerals. In the following description, a flexible original that can be bent like plain paper is called a sheet original, and a hard and inflexible original like a resin card is called a card original for convenience.

  FIG. 1 schematically shows a basic configuration of an image reading apparatus according to the present invention. The image reading apparatus 1 shown in FIG. 1 is for reading an image on the surface of a card document, and has a document placement unit 2 for storing a card document C at one end thereof. The image reading apparatus 1 includes a document feed path 3 that is horizontal and linear from the document placing unit 2 toward the other end. An image reading unit 4 is disposed substantially at the center of the document conveyance path 3 and immediately above it. At the end of the document conveyance path 3, a discharge tray 5 for receiving a card document discharged from the document conveyance path is attached.

  The document placing portion 2 can place a plurality of card documents C stacked horizontally on the placing surface 2a at the bottom. A feeding roller 6 is provided on the lower side of the document placing portion 2, and the upper end thereof is disposed so as to protrude somewhat from the opening of the placement surface 2a onto the placement surface.

  In the document placing portion 2, a partition wall 7 is erected at the upstream end of the document conveyance path 3. A gap 7a is formed between the lower end of the partition wall 7 and the upper surface of the original transport path so as to allow only one card original to pass through. A plurality of card documents C stacked on the document placement unit 2 can be fed to the document conveyance path 3 one by one from the bottom by rotating the feeding roller 6 through the gap 7a.

  In the document conveyance path 3, a pair of upper and lower lead rollers 8 sandwiching the document conveyance path on the upstream side of the image reading unit 4, and a pair of upper and lower sides sandwiching the document conveyance path on the downstream side of the image reading unit. The discharge roller 9 is provided. Each of the lead roller 8 and the discharge roller 9 is a main driving roller in which one roller of each pair is rotated by driving means such as a motor, and the other roller is a driven roller. Further, a platen 10 is disposed in the document conveyance path 3 immediately below the image reading unit 4.

  The image reading unit 4 is a single image sensor unit made of CIS, and is provided in a substantially rectangular box-shaped housing 11, an illumination device 12, a rod lens array 13, a light receiving sensor 14, and a lower surface of the housing 11. Platen glass 15. Illumination light emitted from the illuminating device 12 is reflected from the original surface of the card document at the image reading position, is incident on the lower surface of the rod lens array 13, is emitted from the upper surface, and forms an image on the light receiving sensor 14. .

  The normal image reading unit 4 is installed at a standard position with a height that defines a certain gap 16 between the lower surface of the platen glass 15 and the upper surface of the platen 10 in the document conveyance path 3. The standard position is set so that one card document can pass through the gap 16 and the height position of the document surface is within the range of the focal depth of the rod lens array 13.

  The housing 11 of the image reading unit 4 can be displaced so as to approach / separate in the vertical direction with respect to the document conveying path 3 by an elevating unit 17 provided above the housing 11. The housing 11 can be configured such that the entire image reading unit 4 is displaced integrally. In another embodiment, other components of the image reading unit may be fixed and only the housing may be displaced.

  The image reading unit 4 can be lowered to a predetermined height from the standard position toward the upper surface of the platen 10 by the elevating means 17. The height of the descending position is set so that at least the side wall 11a on the upstream side of the housing 11 is small enough to prevent the passage of one card document. Therefore, the image reading unit 4 may or may not contact the upper surface of the platen 10 at the lowered position.

  Next, the operation of the image reading apparatus 1 will be described in order with reference to FIGS. First, the feeding roller 6 is rotated so that the lowermost card document C is separated from the document placement unit 2 by the partition wall 7 and fed to the document conveyance path 3. The delivered card document C is nipped at the leading end of the pair of lead rollers 8 (FIG. 2A), and is further transported toward the image reading unit 4 along the document transport path 3 by the rotation of the lead rollers.

  The raising / lowering means 17 operates when the leading edge of the card document C reaches a certain position, and lowers the image reading unit 4 from the standard position to the lowered position. As a result, the document conveying path 3 below the image reading unit 4 is closed, and the card document C stops with its leading end abutting against the side wall 11a of the housing 11 (FIG. 2B). After the card document C is stopped, the read roller 8 continues to rotate for a predetermined time and then stops. As a result, the front end position of the card document C can be aligned and the skew can be corrected.

  The timing of the lowering operation by the elevating means 17 can be determined by, for example, a change in pressure received by the lead roller 8 when the leading edge of the card document C is nipped by the pair of lead rollers 8. It is also possible to provide a separate detection sensor at a position upstream of the image reading unit 4 in the document transport path 3 to detect the leading end position of the card document C and to operate the lifting means 17.

  In another embodiment, after the image reading apparatus 1 is turned on and the initial operation is completed, or after the reading of the card document C is completed, the elevating means 17 is operated to lower the image reading unit 4. Also good. If the image reading section 4 is lowered to the lowered position by the lifting / lowering means 17 before the next card document C is fed to the document transport path 3 by rotating the feeding roller 6, the next card document C C stops with its tip abutting against the side wall 11 a of the housing 11. In this way, when the card document C can be read, the timing of the lowering operation of the image reading unit can be controlled more easily by ensuring that the image reading unit 4 is in the lowered position.

  After the read roller 8 is stopped, the lifting / lowering means 17 is operated to raise the image reading unit 4 from the lowered position to the standard position. As a result, the front end of the card document C is released from contact with the housing side wall 11a, and again passes under the image reading unit 4 along the document transport path 3 by the rotation of the lead roller 8 (FIG. 2 ( C)). As the raising / lowering means 17, for example, an actuator made of an electromagnetic solenoid can be used.

  The card document C that has passed through the image reading unit 4 is nipped between the leading end of the discharge roller 9 and is discharged to the outside from the document transport path 3 by the rotation of the lead roller (FIG. 2D). The card document C completely discharged to the outside falls to the discharge tray 5.

  The image reading apparatus 1 shown in FIG. 1 reads an image only on the front side of a card document, but may be configured to read images on both the front and back sides of the document. For example, as indicated by an imaginary line in FIG. 1, an additional image reading unit 18 is disposed on the lower side of the document conveyance path 3 so as to face the image reading unit 4. At this time, the platen 10 of the document conveying path 3 is removed, and the platen glass of the additional image reading unit 18 is disposed at that position.

  The image reading apparatus according to the present invention can be applied not only as a card original reading apparatus but also to various apparatuses such as a digital compound copying machine, a facsimile, and an image scanner.

  FIG. 3 is a cross-sectional view showing a first embodiment of an image reading apparatus having an automatic document feed (ADF) function. The image reading apparatus 20 of this embodiment can be used for both sheet originals and card originals, and is configured to read images on both the front and back sides of the original. The image reading apparatus 20 includes a lower unit 21 and an upper unit 22 constituting an ADF attached to the lower unit so as to be opened and closed.

  The lower unit 21 is provided with a first platen glass 23 on the upper surface thereof, and a first image reading unit 24 for reading the lower surface of the document passing over the first platen glass 23 is disposed immediately below the first platen glass 23. ing. The first image reading unit 24 is a CIS having an illumination device 25, a rod lens array 26, and a light receiving sensor 27 in a housing. The first image reading unit 24 is mounted on the carriage so as to be horizontally movable in order to scan and read a document placed on the platen adjacent to the first platen glass 23.

  In the upper unit 22, a second image reading unit 28 is disposed so as to face the first image reading unit 24 with the first platen glass 23 of the lower unit 21 interposed therebetween. Similarly, the second image reading unit 28 is a CIS, and includes a lighting device 30, a rod lens array 31, and a light receiving sensor 32 in a housing 29, and a second platen glass 33 on the lower surface of the housing 29.

  Further, the upper unit 22 includes a paper feed tray 33 for stacking and placing a plurality of sheet originals S, an ADF main body 34 for carrying out image reading processing by conveying the sheet originals from the paper feed tray, A first discharge tray 35 for discharging and storing the processed sheet document; Inside the upper unit 23, a first document transport path 36 for transporting a sheet document from the paper feed tray 33 to the first paper discharge tray 35 is provided.

  A first feeding roller 37 for contacting the uppermost sheet document S on the sheet feeding tray 35 and feeding it to the first document transport path is arranged on the first document transport path 36 on the most upstream side. It is installed. Immediately downstream thereof, a sheet separation mechanism is provided that includes a first paper feed roller 38 that reliably separates the fed sheet originals one by one and a separation pad 39 that abuts on the first paper feed roller 38.

  Further, a pair of first read rollers 40 for transporting the sheet document to the reading position is disposed on the first document transport path 36 on the downstream side of the second image reading unit on the upstream side of the second image reading unit 28. In addition, a pair of second lead rollers 41 for feeding the sheet document in the discharge direction are arranged. A pair of paper discharge rollers 42 for discharging the sheet originals to the first paper discharge tray 35 is disposed at the end of the first document transport path 36.

  A paper feed opening 43 for the card original C is opened at substantially the center of the paper feed tray 33, and a card inclined to receive a plurality of card originals C and to guide it below the paper feed tray. A paper feed guide 44 is provided. The opening width of the paper feed port 43 is set to be larger than the width dimension of the card document assumed in advance. At the end of the lower unit 21 opposite to the first paper discharge tray 35, a second paper discharge tray 45 for discharging and storing the card document that has been read is provided.

  Inside the upper unit 23, a second document transport path 46 for transporting the card document from the card paper feed guide 44 to the second paper discharge tray 45 is provided. A second feeding roller 47 for contacting the uppermost card document C in the card feeding guide 44 and feeding the card document C to the second document conveying path is provided at the most upstream side of the second document conveying path 46. Has been. Furthermore, a card separation mechanism is provided on the same axis as the second feeding roller 47, which includes a second paper feed roller 48 that reliably separates the card documents one by one and a separation roller 49 that abuts on the second paper feed roller 48.

  A generally L-shaped card transport guide 50 having a horizontal bottom surface 50a and a generally vertical rear wall surface 50b is provided immediately below the second paper feed roller 48 in order to level the card document that has been obliquely fed out. It has been. A paddle roller 51 is rotatably provided on the card transport guide 50 so as to protrude from the rear wall surface. The paddle roller 51 prevents the trailing edge of the falling card document from being caught on the rear wall surface 50b, and the card document is reliably placed horizontally on the bottom surface 50a. As a result, a substantially horizontal and linear card document conveyance path is defined that passes between the first and second image reading units 24 and 28 from the bottom surface 50a of the card conveyance guide 50 to the outside.

  A third lead roller 52 is disposed between the card conveyance guide 50 and the second image reading unit 28 above the second document conveyance path 46. Further, a fourth read roller 53 is disposed on the upper side of the second document conveyance path 46 immediately downstream of the second image reading unit 28.

  Similar to the image reading unit 4 of the image reading apparatus 1 in FIG. 1, the second image reading unit 28 is predetermined with respect to the first platen glass 23 constituting a part of the first and second document transport paths 36 and 46. It is installed at a standard position in height. The height of the standard position is such that the sheet document and the card document can pass through the gap between the second platen glass 33 and the first platen glass 23, and the height position of the document surface is the focal point of the rod lens array 31. Set to be within depth.

  The second image reading unit 28 can be displaced so as to approach and separate from the first platen glass 23 in the vertical direction by lifting means (not shown). In the present embodiment, the entire second image reading unit 28 is configured to be displaced integrally. However, it may be configured such that only the housing 29 of the second image reading unit 28 is displaced.

  The second image reading unit 28 can be lowered by the lifting / lowering unit from the standard position toward the upper surface of the first platen glass 23 so as to block the document conveyance path. This lowering is such that at least the side walls 29a and 29b on the front and rear sides of the housing 29 come into contact with the upper surface of the first platen glass 23, and one sheet document and card document cannot enter between them. Set.

  An operation when a card document is read by the image reading device 20 will be described. First, when the card document C is placed on the card feed guide 44, the detection sensor 54 detects this, and when a reading switch (not shown) is turned on, the second feed roller 47 and the second feed roller 48 are turned on. By rotation, the card document C is fed to the second document transport path 46 one by one.

  The card document C fed out from the second feeding roller 47 is detected by the detection sensor 55 when dropped onto the card transport guide 50, and the second image reading unit 28 is lowered correspondingly, and the side wall 29a of the housing 29, 29b comes into contact with the upper surface of the first platen glass 23 and blocks the second document conveyance path 46 (FIG. 4A).

  At the same time, the third read roller 52 moves so as to contact the upper surface of the card document C disposed horizontally on the bottom surface 50a of the card conveyance guide 50, and rotates to rotate the card document C to the second image reading unit. Feed toward 28. The card document C is stopped by bringing its leading end into contact with the upstream side wall 29 a of the housing 29. The third read roller 52 stops after the card document C is stopped after being rotated for a predetermined time. As a result, the front end position of the card document C can be aligned and the skew can be corrected.

  After stopping the third lead roller 52, the lifting / lowering means is operated to raise the second image reading unit 28 to the standard position. As a result, the front end of the card document C is released from contact with the housing side wall 29a. By rotating the third read roller 52 again, the card document C is transported along the second document transport path 46, and images on both the front and back surfaces are read by the first image reading unit 24 and the second image reading unit 28 ( FIG. 4 (B)).

  The card document C that has passed through the first and second image reading units 24, 28 is discharged by the rotation of the fourth lead roller 53, and is dropped and stored in the second paper discharge tray 45. The discharge of the card document C is detected by the detection sensor 56 provided at the position of the fourth read roller 53. If there is no card document to be read after that, the reading process is terminated.

  The image reading apparatus 20 operates in the same manner as the card document described above when reading a sheet document. First, when the sheet document S is placed on the paper feed tray 33, this is detected by the detection sensor 57 provided at the position of the first feeding roller 37, and when the reading switch (not shown) is turned on, the first feeding roller. The sheet document S is fed to the first document transport path 36 one by one by the rotation of the first sheet feed roller 38 and the first sheet feed roller 37.

  When the leading edge of the sheet document S passes in front of the first lead roller 40, this is detected by the detection sensor 58, and the second image reading unit 28 is lowered and the fourth lead roller 53 is raised correspondingly. 4A, the side walls 29a and 29b of the housing 29 come into contact with the upper surface of the first platen glass 23 to block the first document transport path 36.

  The sheet document S is continuously fed toward the second image reading unit 28 by the rotation of the first read roller 40, and the front end of the sheet document S is brought into contact with the upstream side wall 29b of the housing 29 and stopped (FIG. 4 ( C)). The first read roller 40 is rotated after a certain period of time after the sheet document S is stopped and then stopped. Thus, the leading edge position of the sheet document S can be aligned and the skew can be corrected.

  After the first lead roller 40 is stopped, the fourth lead roller 53 is lowered, and the skew-corrected sheet document S is sandwiched between the upper surface of the first platen glass. Thereafter, the first lead roller pair 40 is separated from each other by an operating mechanism (not shown) such as a solenoid. By this operation, the slack that can be generated between the sheet document S skew-corrected by the side wall 29b of the housing 29 and the first lead roller 40 can be made constant in the document transport direction.

  Thereafter, the first lead roller 40 is nipped again with the sheet document S, and the fourth lead roller 53 is retracted upward. Then, the elevating means is operated to raise the second image reading unit 28 to the standard position. As a result, the contact of the front end of the sheet document S with the housing side wall 29b is released. By rotating the first read roller 40 again, the sheet document S is transported along the first document transport path 36, and both the front and back images are read by the first image reading unit 24 and the second image reading unit 28.

  The sheet document S that has passed through the first and second image reading units 24 and 28 is conveyed toward the first sheet discharge tray 35 by the rotation of the second lead roller 41, and the first discharge is performed by the rotation of the sheet discharge roller 42. It is discharged and stored in a paper tray. The discharge of the sheet original S is detected by a detection sensor 59 provided in front of the paper discharge roller 42. If there is no sheet original to be read thereafter, the reading process is terminated (FIG. 4D).

  5A and 5B show the main part and the operation of the second embodiment of the image reading apparatus 20. A case where a card document is read in the second embodiment will be described. In the second embodiment, the second image reading unit 28 is fixed at the standard position, and the lifting means of the second image reading unit is omitted. Instead, the second image reading unit 28 can be moved up and down on the bottom surface 50a of the card transport guide 50. A guide 60 is provided.

  The auxiliary guide 60 is set so that its upper surface is higher than the lower end of the housing 29 of the second image reading unit 28 in the initial state. When the card document C fed from the card feeding guide 44 by the second feeding roller 47 falls on the card transport guide 50, it is arranged on the upper surface of the auxiliary guide 60. In this state, the third read roller 52 is rotated to feed the card document C toward the second image reading unit 28.

  The card document C transported at a position higher than the second document transport path 46 stops with its leading end abutting against the upstream side wall 29a of the housing 29 (FIG. 5A). The third read roller 52 stops after the card document C is stopped after being rotated for a predetermined time. As a result, the front end position of the card document C can be aligned and the skew can be corrected.

  After the third lead roller 52 is stopped, the auxiliary guide 60 is lowered until the upper surface thereof becomes the same height as the bottom surface 50 a of the card transport guide 50. In another embodiment, the auxiliary guide 60 may be lowered below the bottom surface 50a of the card transport guide 50 so that the card document C is disposed on the bottom surface 50a.

  As a result, the front end of the card document C is released from contact with the housing side wall 29a. By rotating the third read roller 52 again, the card document C is transported along the second document transport path 46, and images on both the front and back surfaces are read by the first image reading unit 24 and the second image reading unit 28 ( FIG. 5 (B)). When the card document C is read, the auxiliary guide 60 returns to the initial height.

  Next, a case where a sheet document is read in the second embodiment will be described. In the first document conveyance path 36 of the second embodiment, a conveyance guide 61 that can be moved up and down is provided just upstream of the second image reading unit 28 in the same manner as the auxiliary guide 60 for card documents. The conveyance guide 61 is set so that its upper surface is higher than the lower end of the housing 29 of the second image reading unit 28 in the initial state.

  The sheet document S fed toward the second image reading unit 28 by the rotation of the first read roller 40 is transported on the upper surface of the transport guide 61 located at a position higher than the first document transport path 36, and the front end of the sheet document S is housing. It stops by contacting with the side wall 29b on the upstream side of 29 (FIG. 5C). The first lead roller 40 stops after the sheet document S is stopped and continues to rotate for a predetermined time. Thereby, the front end position of the sheet document S can be aligned and the skew can be corrected.

  After stopping the first read roller 40, the conveyance guide 61 is lowered until the upper surface thereof becomes the same height as the first document conveyance path 36. In another embodiment, the conveyance guide 61 can be lowered below the first document conveyance path 36 so that the sheet document S is arranged on the first document conveyance path 36.

  As a result, the contact of the front end of the sheet document S with the housing side wall 29b is released. By rotating the first read roller 40 again, the sheet document S is transported along the first document transport path 36, and images on both the front and back surfaces are read by the first image reading unit 24 and the second image reading unit 28 ( FIG. 5 (D)). When the sheet document S is read, the conveyance guide 61 returns to the initial height.

  6A and 6B show the main part and the operation of the third embodiment of the image reading apparatus 20. In the third embodiment, the second image reading unit 28 is provided so as to tilt forward and backward with respect to the transport direction about the horizontal rotation shaft 62 orthogonal to the transport direction of the document with respect to the document transport path. ing. The tilt of the second image reading unit 28 is performed in the same manner as in the first embodiment of FIG. 4 by a driving unit (not shown).

  FIG. 6A shows a case where the second image reading unit 28 is tilted backward from the standard position with respect to the conveyance direction of the second document conveyance path 46. In the second image reading unit 28, the side wall 29 a of the housing 29 rotates around the rotation shaft 62 in the clockwise direction in the figure, and the lower end of the side wall abuts on the upper surface of the second document transport path 46. The transfer route is blocked.

  As a result, the card document C fed by the rotation of the third lead roller 52 is brought into contact with the side wall 29 a of the housing 29 and stopped. The third read roller 52 stops after the card document C is stopped after being rotated for a predetermined time. As a result, the front end position of the card document C can be aligned and the skew can be corrected.

  After the third lead roller 52 is stopped, the second image reading unit 28 is returned to the standard position by being rotated in the reverse direction by the driving means. As a result, the front end of the card document C is released from contact with the housing side wall 29a. By rotating the third read roller 52 again, the card document C is transported along the second document transport path 46, and the first and second image reading units 24 and 28 can read the images on both the front and back surfaces. it can.

  FIG. 6B shows a case where the second image reading unit 28 is tilted backward from the standard position with respect to the conveyance direction of the first document conveyance path 36. In the second image reading section 28, the side wall 29 b of the housing 29 rotates counterclockwise in the figure around the rotation shaft 62, and the lower end of the side wall abuts on the upper surface of the first document transport path 36. The document transport path is blocked.

As a result, the sheet document S fed by the rotation of the first lead roller 40 is brought into contact with the side wall 29b of the housing 29 and stopped. The first lead roller 40 stops after the sheet document S is stopped and continues to rotate for a predetermined time. Thus, the leading edge position of the sheet document S can be aligned and the skew can be corrected.

  After the first lead roller 40 is stopped, the fourth lead roller 53 is lowered, and the skew-corrected sheet document S is sandwiched between the upper surface of the first platen glass. Thereafter, the first lead roller pair 40 is separated from each other by an operating mechanism (not shown) such as a solenoid. By this operation, the slack that can be generated between the sheet document S skew-corrected by the side wall 29b of the housing 29 and the first lead roller 40 can be made constant in the document transport direction.

  Thereafter, the first lead roller 40 is nipped again with the sheet document S, and the fourth lead roller 53 is retracted upward. Then, the driving unit is operated in the reverse direction to return the second image reading unit 28 to the standard position. As a result, the contact of the front end of the sheet document S with the housing side wall 29b is released. By rotating the first read roller 40 again, the sheet document S is transported along the first document transport path 36, and the images on both the front and back surfaces can be read by the first image reading unit 24 and the second image reading unit 28. it can.

  FIG. 7 shows the configuration of the fourth embodiment of the image reading apparatus 20. In the fourth embodiment, the illumination devices 25 and 30 of the first image reading unit 24 and the second image reading unit 28 are arranged on the upstream side of the rod lens arrays 26 and 31 in the card document conveyance direction, respectively. Further, the optical axes 26 a and 31 a of the rod lens arrays 26 and 31 of the first and second image reading units are arranged at different positions along the second document conveyance path 46.

  Generally, in order to read a document stably and clearly with CIS, it is preferable that the document surface passes through a reading position at a predetermined constant reading speed. In the image reading apparatus of the present invention described above, the card document is temporarily stopped at the housing side wall 29a of the second image reading unit 28, skew correction is performed, and then conveyance is started again. Therefore, it is preferable to accelerate the card document conveyance speed from the stopped state to a desired reading speed before passing the reading position. However, rapid acceleration of the card document may cause the conveyance speed to become unstable.

  In the fourth embodiment, the illumination devices 25 and 30 of the first and second image reading units are arranged on the upstream side of the rod lens arrays 26 and 31, so that the card document is accelerated to a desired reading speed. The conveyance distance can be set longer. Accordingly, rapid acceleration of the card document once stopped can be avoided, and a stable conveyance speed can be obtained.

  Further, if the irradiated light is irradiated in the same direction from the first and second image reading units 24 and 28 that are arranged to face each other, they may interfere with each other to lower the reading accuracy or adversely affect the reading. In the fourth embodiment, the arrangement of the optical axes 26a and 31a of the rod lens arrays 26 and 31 of both the image reading units as described above effectively prevents interference of irradiation light.

  As mentioned above, although this invention was demonstrated in relation to the preferred embodiment, this invention is not limited to the said embodiment, In the technical scope, it can implement with a various change or deformation | transformation. Needless to say. For example, in the above-described embodiment, the transport path between the sheet document and the card document is reversed to reduce the size of the entire apparatus. However, the sheet document and the card document can be transported in the same direction. .

DESCRIPTION OF SYMBOLS 1,20 Image reading apparatus 2 Original placing part 3 Original conveying path 4 Image reading part 11 Housing 17 Lifting means 24 First image reading part 28 Second image reading part 29 Housing 33 Paper feed tray 36 First original conveying path 44 Card Paper feed guide 46 Second document transport path 50 Card transport guide 60 Auxiliary guide 61 Transport guide

Claims (11)

An image reading unit including a reading unit that reads an image of a document and a housing that holds the reading unit;
A document conveyance path having a reading position of the document;
A document feeding means for transporting a document along the document transport path;
Moving means for relatively moving the document conveying path and the housing;
Control means for controlling the document feeding means and the moving means,
The control means temporarily stops the document transported along the document transport path by bringing the leading end of the document into contact with the housing before the reading position, and then releases the contact with the housing. An image reading apparatus that conveys the document conveyance path so as to pass through the reading position.   2. The image reading according to claim 1, wherein the housing is displaceable between a first position where the document can pass through the document transport path and a second position where the leading edge of the document can abut. apparatus.   The image reading apparatus according to claim 2, wherein the housing is displaceable between the first position and the second position by moving up and down with respect to the document conveyance path.   3. The image reading apparatus according to claim 2, wherein the housing is displaceable between the first position and the second position by inclining about an axis orthogonal to the conveyance direction with respect to the document conveyance path.   The document transport path is released from the first position where the leading edge of the document transported by the document feeding means contacts the housing, and the contact between the leading edge of the document and the housing is released. The image reading apparatus according to claim 1, wherein the image reading apparatus is displaceable between a second position that can be conveyed to the second reading position.   The image reading according to claim 5, wherein the document transport path includes a guide member capable of changing a transport height of the document so that a document feeding direction is changed between the first position and the second position. apparatus.   7. The contact image sensor according to claim 1, wherein the reading unit includes a contact image sensor including an illumination device that illuminates a document surface, a light receiving sensor, and a rod lens array that forms an image of reflected light from the document surface on the light receiving sensor. An image reading apparatus according to claim 1.   The image reading unit includes a first image reading unit including a reading unit that reads the document conveyed on the document conveyance path from above, and further includes a second image reading unit including a reading unit that reads the document from below. The image reading apparatus according to claim 1. The reading means of the first and second image reading units each include an illumination device that illuminates the document surface, a light receiving sensor, and a rod lens array that forms an image of reflected light from the document surface on the light receiving sensor. It consists of a close-contact image sensor,
The illumination devices of the reading means of the first and second image reading units are respectively arranged on the upstream side of the document conveyance path with respect to the rod lens array, and the reading units of the first and second image reading units The image reading apparatus according to claim 8, wherein optical axes of the rod lens array are arranged at different positions along the document conveyance path.   10. The document feeding path according to claim 1, wherein the document feeding path includes a first document feeding path for feeding the flexible document and a second document feeding path for feeding the inflexible document. The image reading apparatus described in 1. The image reading apparatus according to claim 10, wherein a document transport direction of the first document transport path passing through the reading position and a document transport direction of the second document transport path are opposite to each other.

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