JP4830156B2 - Document duplex scanning device - Google Patents

Description

The present invention relates to a document double-sided reading device , and more particularly to a document double-sided reading device suitable for reading both sides of a relatively small-sized document such as a home facsimile machine or a small document scanner.

  In household and relatively inexpensive facsimile machines, only one set of one-dimensional image sensors as elements for reading images is often used. In such a facsimile machine, having a function of automatically reading not only one side of a document but also both sides is a big point for differentiating products. For this reason, it is possible to invert a document that has been read on one side, convey it to a one-dimensional image sensor that has previously read an image, and read the other side. (For example, refer to Patent Document 1).

  FIG. 15 shows the main part of the configuration of a double-sided reading apparatus that reads the both sides of the original by inverting the original according to the same principle as the related art. The double-sided reading apparatus 100 includes a separation roller 104 that separates and conveys an arbitrary number of originals 103 set on an original supply tray 102 of the apparatus main body 101 one by one. The separation roller 104 is in rolling contact with the rubber plate 105, and a document presence / absence sensor 106 for detecting the presence / absence of the document 103 is arranged slightly upstream from the rolling contact point.

  Slightly downstream of the separation roller 104, a first merge point 109 where the start point of the horizontal conveyance path 107 that moves the separated original 103 straight and the end point of the reverse conveyance path 108 that conveys the inverted original merge. Is present. A first document leading edge / rear edge detection sensor 111 for detecting the leading edge and trailing edge of the document 103 is disposed slightly below the first junction 109. A reading device 113 using a pressing spring 112 and a CIS (Contact Image Sensor) pressed by the pressing spring 112 is disposed between the horizontal conveyance path 107 and the apparatus main body 101. The reading device 113 is in pressure contact with the feed roller 114 across the horizontal conveyance path 107, and the image of the original 103 is read line by line here. The reading device 113 using the CIS has been commercialized as a reading device in which a light source, a reading sensor, and an input / output circuit are housed in one casing, and a feed roller having a length equivalent to the reading width of the document is required. Become. This is different from a reading device that forms an image with a reduction optical system using a mirror or a lens on a CCD having a width shorter than the reading width of an original.

  The end point of the horizontal conveyance path 107 joins the start point of the reversal conveyance path 108 and the second junction 115. The reversing conveyance path 108 is a conveyance path for reversing the original after the image information on one side is read and causing the reading device 113 to perform reading via the first junction 109. In the reversing conveyance path 108, a reversing conveying roller 116 and a pinch roller 117 that is in rolling contact with the reversing conveying roller 116 are arranged for conveying the document. In addition, a discharge roller 118 and a pinch roller 119 that is in rolling contact with the discharge roller 118 are disposed slightly downstream of the second junction 115.

  FIG. 16 specifically shows the movement of the two sensors in the vicinity of the separation roller of the double-sided reading device. The document presence / absence sensor 106 disposed on the upstream side of the separation roller 104 is a sensor having a mechanical actuator, and is constituted by a microswitch or an optical sensor that turns on and off the passage of light in conjunction with this actuator. Can do. The same applies to the first document leading edge / rear edge detection sensor 111 disposed on the downstream side of the separation roller 104.

  When the document 103 shown in FIG. 15 does not pass between the separation roller 104 and the rubber plate 105, that is, when the document 103 is not detected, the actuator of the document presence / absence sensor 106 is in a position indicated by a solid line. In contrast, when the document 103 passes between the separation roller 104 and the rubber plate 105, the actuator of the document presence / absence sensor 106 moves to the position indicated by the broken line to detect that the document 103 does not exist. .

  With respect to the first document leading edge / rear edge detection sensor 111, the actuator is in a position indicated by a solid line when the document 103 is not detected. Further, when the document 103 is detected, the actuator has moved to the position indicated by the broken line.

  FIG. 17 shows a state in which the originals stacked on the original supply tray are sent out. It is assumed that a plurality of documents 103 are set on the document supply tray 102 as shown in FIG. The rubber plate 105 is disposed such that its surface forms a predetermined acute angle with respect to these originals 103. Therefore, as the plurality of documents 103 set on the document supply tray 102 are arranged in the lower layer, the leading ends of the documents 103 are arranged one step further downstream from the rubber plate 105. Further, the document presence / absence sensor 106 detects that “there is a document” by the actuator being pushed by these documents 103.

  When the separation roller 104 rotates in the direction of the arrow 121 in this state, only the lowermost document 103L in contact with the document supply tray 102 is separated from the remaining documents and sent out in the downstream direction indicated by the arrow 122. The delivered document 103L is detected by rotating the actuator of the first document leading edge / rear edge detection sensor 111 by a predetermined angle as shown in the figure. In this state, the original 103 is conveyed between the reading device 113 and the feed roller 114 in the direction of the arrow 122, and the image reading by the one-dimensional image sensor 123 arranged in the main scanning direction is performed in units of lines. The document 103 whose image has been read is conveyed downstream in the horizontal conveyance path 107 as shown in FIG. Then, the document passes between the discharge roller 118 and the pinch roller 119 and is conveyed in the direction of the arrow 122.

  As described above, an image is read on one side of the original 103. Next, a case where both sides of the original 103 are read will be described. In this case, the rotation directions of the discharge roller 118 and the pinch roller 119 are reversed immediately before the trailing edge of the document 103 passes between the discharge roller 118 and the pinch roller 119. Then, the location that has been the trailing edge of the original 103 is changed to the leading edge, and this time, it is fed into the reversing conveyance path 108. Then, the conveyance force by the reversing conveyance roller 116 and the pinch roller 117 enters the horizontal conveyance path 107 again from the first junction 109 and the one-dimensional image sensor 123 reads the image on the remaining surface. . The separation roller 104 of the double-sided reading device 100 is provided with a one-way mechanism.

  FIG. 18 shows a one-way mechanism. The one-way mechanism includes a transmission gear 131 that receives transmission of rotational force from a drive source (not shown), a one-way spring 132 that has one end inserted into a cylindrical portion 131A that constitutes the transmission gear 131, and a roller shaft 104A that is connected to the one-way spring 132. The separation roller 104 is inserted on the other end side. A slit 131B is formed in the cylindrical portion 131A of the transmission gear. The end on one end side of the one-way spring 132 is bent in the direction of about 90 degrees with respect to the axial direction of the spring to constitute a bent portion 132A. When the one-way spring 132 is attached to the cylindrical portion 131A, the bent portion 132A is inserted into the slit 131B and inserted from one end side of the one-way spring 132.

  In such a one-way mechanism, when the transmission gear 131 rotates in the direction of the arrow 133, the bending portion 132A rotates in a direction in which the inner diameter of the one-way spring 132 becomes smaller. As a result, the roller shaft 104A rotates in the direction of the arrow 133 as the transmission gear 131 rotates.

  On the other hand, when only the separation roller 104 is given a rotational force in the direction of the arrow 133 while the transmission gear 131 is not rotating, the inner diameter of the one-way spring 132 is increased. As a result, the separation roller 104 can rotate independently of the transmission gear 131 even when the transmission gear 131 stops rotating.

  Next, the operation of the double-sided reading apparatus 100 configured as described above will be described. First, it demonstrates using FIG.

  Assume that a document 103 is set on a document supply tray 102 of the apparatus main body 101. When the document 103 is set, the actuator of the document presence / absence sensor 106 rotates from the state shown by the solid line in FIG. 16 to an angle as shown in FIG. Thereby, the original 103 is detected. As a result, the drive source described above starts to transmit the rotational force to the transmission gear 131 shown in FIG. 17, and the separation roller 104 starts to rotate in the direction of the arrow 121 by the one-way mechanism.

  When the separation roller 104 starts to rotate, assuming that there are a plurality of documents 103 as shown in FIG. 17, the documents 103 are separated from the lowermost layer side by sheet due to the frictional force between the rubber plate 105 and the separation roller 104. The sheets are separated and sent one by one by the separation roller 104. Now, pay attention to one original 103. The separation roller 104 conveys the leading edge of the original 103 until it passes between the one-dimensional image sensor 123 disposed on the reading device 113 and the feed roller 114. It should be noted that the other documents 103 set on the document supply tray 102 at this time are in a stopped state because their leading end portions are pressed against the rubber plate 105.

  By the way, when the trailing edge of the first document 103 leaves the nip region between the separation roller 104 and the rubber plate 105, the second document 103 comes into direct contact with the feed roller 114. At this point, the rubber plate 105 is brought into contact. The friction force is overcome and the conveyance is started. In the double-sided reading apparatus 100, the peripheral speed of the separation roller 104 is set to be slower than that of the feed roller 114. Accordingly, since the first original 103 has already been conveyed by the feed roller 114, the interval between the two is separated before the second original 103 reaches the reading device 113. That is, an area where no document exists is generated between the trailing edge of the first document 103 and the leading edge of the second document 103. The first document leading edge / rear edge detection sensor 111 detects this area with the actuator, and determines the trailing edge of the first document 103 and the leading edge of the second document 103.

  By the way, when the document 103 is captured by the feed roller 114, the conveyance speed of the separation roller 104 is slower than that of the feed roller 114, so that a phenomenon in which the document 103 is pulled by these rollers occurs. This is prevented by the one-way mechanism described with reference to FIG. That is, the separation roller 104 rotates with the movement of the document 103 at a rotational speed faster than the rotational speed by driving the transmission gear 131.

  By the way, when passing between the one-dimensional image sensor 123 and the feed roller 114, the image information on the document 103 is scanned in plane and read in line units. When the image is scanned in this manner and the trailing edge of the document 103 is detected by the first document leading edge / rear edge detection sensor 111, the double-sided reading device 100 detects the end time of the image scanning. Depending on the apparatus, it is possible to delay the detection determination timing of the trailing edge of the document 103 until a predetermined time has elapsed since it is determined whether the detection information of the leading edge / rear edge detection sensor 111 is a reliable operation. When the trailing edge of the image reading area is detected in this way, the feed roller 114 accelerates its rotation and discharges the document 103 in the direction of the arrow 122. FIG. 15 shows a state in which the original 103 is discharged out of the apparatus by the discharge roller 118 and the pinch roller 119.

  Next, a case where both sides of a document are read by the double-sided reading device 100 will be described. In this case, the drive control of each part of the apparatus is more complicated than described above. For example, the separation roller 104 is a mechanism that is driven independently only when the first side of the original 103 is read. This will be described with reference to FIG.

  After the first one side is read by the one-dimensional image sensor 123, the document 103 is discharged out of the apparatus by the discharge roller 118 and the pinch roller 119 as described above. When reading of both sides of the document 103 is instructed, a second document leading edge / rear edge detection sensor (not shown) detects this when the trailing edge reaches the second junction 115. Then, the discharge roller 118 is reversely rotated at a predetermined timing before the trailing edge of the document 103 passes through the nip region between the discharge roller 118 and the pinch roller 119. As a result, the original 103 is fed into the reversing conveyance path 108 by the action of a direction switching means such as a valve (not shown) with the rear end portion at the time of conveyance so far as the front end portion.

  The separation roller 104 and the feed roller 114 do not rotate in a state where the document 103 is conveyed using the reversing conveyance path 108. The reversing conveyance roller 116 also stops driving when the document 103 starts conveying on the reversing conveyance path 108.

  The document 103 is transported through the reversing transport path 108, and the leading end (the rear end when reading the first side of the document 103) reaches the reversing transport roller 116 and the pinch roller 117 that is in contact with the reversing transport roller 116. A third document leading edge / rear edge detection sensor (not shown) detects this and stops conveying the document 103. At this time, the leading end of the original 103 abuts against the rolling contact portion between the reversing conveyance roller 116 and the pinch roller 117.

  In this state, power such as a solenoid (not shown) acts to move the rotation shaft of the discharge roller 118 in a direction to increase the distance between the rotation shaft of the pinch roller 119. The rotating shaft side of the pinch roller 119 may move. As a result, a gap is generated between the discharge roller 118 and the pinch roller 119 that are rotating in the direction in which the document 103 is discharged from the apparatus main body 101.

  In this way, when the document 103 traveling in the reversing conveyance path 108 is not prevented from advancing by the discharge roller 118 and the pinch roller 119, the reversing conveyance roller 116 starts to rotate in the direction of the arrow shown in the drawing. . As a result, the leading edge of the original 103 is conveyed to the first junction 109 by the reverse conveying roller 116 and the pinch roller 117, and is detected by the first original front / rear edge detection sensor 111. The leading end of the original 103 is conveyed on the reading device 113 and is captured by the feed roller 114 rotating in the direction of the arrow. The peripheral speeds of the feed roller 114 and the reverse conveying roller 116 are the same. The discharge roller 118 is still rotating at this point, but is separated from the pinch roller 119. Therefore, there is no adverse effect when the document 103 is conveyed by the feed roller 114. In this way, the image reading by the one-dimensional image sensor 123 for the other surface of the original 103 is performed in line units.

  FIG. 19 shows a state in which an image is read when the inverted document has a relatively long length. If the original 103 is long as shown in the figure, there may be a case where the trailing edge portion similarly passes between the discharge roller 118 and the pinch roller 119 when the leading edge passes between the discharge roller 118 and the pinch roller 119. Even in such a case, the document 103 is conveyed by the feed roller 114 and the reverse conveying roller 116. Therefore, the separation of the discharge roller 118 from the pinch roller 119 does not affect the reading and discharging of the image of the original 103 and does not cause a paper jam.

  Assume that the conveyance further proceeds from the state shown in FIG. 19, and the trailing edge of the original 103 passes through the reversing conveyance path 108 and is detected by the first original leading edge / rear edge detection sensor 111. At this time, the application of power such as the solenoid to the discharge roller 118 is stopped. As a result, after that, the portion of the document 103 that has been read is discharged out of the apparatus main body 101 by the discharge roller 118.

In the double-sided reading device 100 described above, the orientation of the surface when discharged by the discharge roller 118 is reversed between the case where the original 103 is read on only one side and the case where both sides are read. That is, when the upper surface of the original 103 accommodated in a discharge tray (not shown) is read on both sides, the front and back are reversed, and when reading a plurality of originals having continuous pages, the order of the pages is changed. Cannot be bound with a stapler. Therefore, in order to solve such a problem, the document 103 that has been read on both sides is again passed through the reversing conveyance path 108 and reversed, and then discharged to the discharge tray.
JP 61-192634 (specification, second page, lower left column, line 12 to third page, upper left column, seventh line, FIG. 1)

  In the double-sided reading apparatus 100 according to the related technology described in detail above, the number of reading devices is limited to one, and the original is reversed in the conveyance path, and reading is performed a plurality of times. In general, a document reading apparatus that reads an image, such as a copying machine or a facsimile machine, includes a type in which a plurality of reading devices are provided and both front and back surfaces are read by one transport. Since such a document reading apparatus includes a plurality of reading devices, there is an advantage that both sides can be read by one reading operation. Further, since there is no conveyance path for inverting the document, there is an advantage that reading is possible even when the size of the document is small. However, since the reading device is relatively expensive, providing a plurality of high-functional devices such as high resolution leads to a cost increase and increases the size of the apparatus.

  On the other hand, the double-sided reading device 100 according to the related art described with reference to FIGS. 15 to 19 is mainly used in a high-priced device having a large device size because the structure of the device becomes complicated. In this double-sided reading apparatus 100, since both sides of the original 103 are read to read both sides, it is necessary to lengthen the reverse conveyance path 108. As a result, there is a problem that double-sided reading cannot be performed for a short original. there were. In addition, since it is often used in high-priced devices, an inexpensive facsimile or other reading mechanism used for home use cannot automatically perform double-sided scanning, and the user's operation is complicated. There was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a double-sided document reading apparatus capable of automatically reading both sides of a document with a simple configuration.

In the present invention, (a) a document supply tray having a tray surface inclined downward at a predetermined angle so that a plurality of documents can be stacked, and (b) the aforementioned tray surface of the document supply tray is directed downward. A separating roller that is pivotably disposed so that a part of its outer periphery protrudes upward from the extended virtual surface, and (c) a surface that is inclined at an inclination angle larger than the inclination angle of the tray surface described above. A plate-like member having a shape in which the surface is brought into contact with a part of the outer periphery of the separating roller at a predetermined rolling contact point and the surface is extended by a predetermined length above the rolling contact point; (D) separation roller driving means for rotating the separation roller in a predetermined direction when the document is fed from the rolling contact point to the downstream conveyance path; and (e) downstream of the rolling contact point. Feed rollers placed in the transport path (F) Image reading that is arranged at a position where it comes into rolling contact with the feed roller, and sequentially reads the image information on the surface opposite to the rolling contact surface when the document is conveyed downstream by the feed roller. And (g) a feed roller driving means for rotating the feed roller by switching between one of two directions, ie, a direction for conveying the document downstream and a direction for conveying the document in the opposite direction; When it is instructed to read the image information on the other side of the document after reading the image information on one side of the document by the image reading unit, the document is switched in the reverse direction by the feed roller driving unit. This starts the conveyance so that it reaches the position just above the rolling contact point along the outer periphery of the separation roller from below the separation roller. And a feed roller drive control means for moving the distal end of the draft is provided to the original duplex scanning apparatus.

As described above, according to the present invention, when the separation roller rotates in the feeding direction, the document is returned to the position opposite to the rotation position of the separation roller that feeds the document to the position where the document is separated and read one by one. Then, the document is reversed and sent out again to the position where the document is read. Therefore, not only a special conveyance path for inverting the original is not required, but also the separation roller can be used for inverting. Therefore, it is possible to read both sides of a document only with a minimum of two rollers , a separation roller and a feed roller used for reading image information and feeding a document in the direction of the separation roller. It becomes possible to simplify the size and reduce the size, and to reduce the cost.

  Next, an embodiment of the present invention will be described.

  FIG. 1 shows a main part of the configuration of a double-sided reading apparatus according to an embodiment of the present invention. The double-sided reading apparatus 200 according to the present embodiment includes a separation roller 204 that separates and conveys a document (not shown) set on a document supply tray 202 of the apparatus main body 201 one by one. The separation roller 204 is in rolling contact with the rubber plate 205, and a document presence / absence sensor 206 for detecting the presence / absence of a document is disposed slightly upstream from the rolling contact point.

One end of a first horizontal conveyance path 212 is disposed just downstream of the separation roller 204 to allow the separated original to travel straight and pass between the reading unit 209 of the reading device 208 and the feed roller 211. The other end of the first horizontal conveyance path 212 is a document discharge port 213, and a document after reading is stored in a discharge tray (not shown). Further, one end of the second horizontal conveyance path 214 is connected to the one end side of the first horizontal conveyance path 212 through a slight step. The other end of the second horizontal conveyance path 214 is opened to feed the document between the first pinch roller 216 ₁ disposed close to the separation roller 204. The second horizontal conveyance path 214 has an upper guide portion 202A in which a lower end portion of the document supply tray 202 is bent by a predetermined length in a direction opposite to the direction in which the feed roller 211 exists, and a lower interval with the upper guide portion 202A. The lower guide plate 215 is disposed on the side.

By the way, the separation roller 204 is configured to rotate in the direction of the arrow 221 at a predetermined timing. In addition to the _first pinch roller 2161, the separation roller 204 has a roller surface located on the opposite side of the portion where it is in rolling contact with the rubber plate 205, along the movement direction of the roller surface. Pinch rollers 216 ₂ and 216 ₃ are arranged. An endless guide belt 217 is stretched over these first to third pinch rollers 216 _{1 to} 216 ₃ so as to be in rolling contact with the roller peripheral surface for a predetermined section. In the vicinity of the third pinch roller 216 ₃ , a guide portion 202 B having a shape curved from the upper end position of the opening for the separation roller 204 of the document supply tray 202 so as to draw an arc along the surface of the separation roller 204. Are arranged at a slight distance from the roller surface.

  Also in the present embodiment, a pressing spring 219 is disposed between the bottom surface of the reading device 208 and the portion of the apparatus main body 201 facing each other. In addition, an actuator for the leading edge / rear edge detection sensor 220 of the document is disposed on the conveyance path between the rubber plate 205 and the feed roller 211.

  In such a double-sided reading apparatus 200 of the present embodiment, the separation roller 204 is controlled to rotate or stop only in the direction of the arrow 221. On the other hand, the feed roller 211 can perform forward rotation in the direction of arrow 222 and reverse rotation in the direction of arrow 223 opposite to this.

  FIG. 2 shows a driving force transmission mechanism that transmits a driving force to the separation roller and the feed roller. The driving force transmission mechanism 230 includes a driving gear 231 connected to a motor as a driving source (not shown). The drive gear 231 can select either the forward rotation direction indicated by the arrow 232 or the reverse rotation direction opposite to this by control of the rotation direction of the motor. The drive gear 231 meshes with a feed roller gear 233 that transmits a driving force to the feed roller 211 shown in FIG. Therefore, when the drive gear 231 rotates in the forward direction, the feed roller gear 233 rotates in the forward rotation direction indicated by the arrow 234. When the drive gear 231 is reversely rotated, the feed roller gear 233 rotates in the direction opposite to the normal rotation direction indicated by the arrow 234.

  On the other hand, the drive gear 231 includes a planetary arm 235 as a rod-like member that is swingably disposed with the rotation shaft as a fulcrum. At the other end of the planetary arm 235, the rotation shafts of the drive gear 231 and the planetary gear 236 are rotatably attached. Further, a separation roller gear 237 and a large-diameter outer gear 238S are arranged on a non-illustrated non-illustrated member in which the rotation shafts of the driving gear 231 and the feed roller gear 233 of the driving force transmission mechanism 230 are rotatably arranged. Engaged two-stage gears 238 are arranged so that the respective rotation shafts are rotatable.

  Here, the outer gear 238S of the two-stage gear is separated from the planetary gear 236 in the depth direction in the figure and is not in contact. The inner gear 238U of the two-stage gear 238 and the planetary gear 236 are on the same plane.

  In the driving force transmission mechanism 230 having such an arrangement structure, when the drive gear 231 rotates in the forward rotation direction indicated by the arrow 232, the planetary gear 236 rotates in the forward rotation direction indicated by the arrow 241. The planetary gear 236 contains a coil spring (not shown) and applies a constant load to the planetary arm 235. Thus, when the planetary gear 236 rotates in the forward rotation direction indicated by the arrow 241, the planetary arm 235 is given a force for rotating in the arrow 242 direction. As a result, when the drive gear 231 is rotating forward, the planetary gear 236 meshes with the separation roller gear 237 as shown in FIG.

  In this state, the separation roller gear 237 and the planetary gear 236 mesh with each other. As a result, the separation roller gear 237 rotates in the forward rotation direction indicated by the arrow 221 at a lower speed than the case where the planetary gear 236 is assumed to mesh with the inner gear 238U. Will do. Accordingly, the two-stage gear 238 rotates in the forward rotation direction indicated by the arrow 244.

  FIG. 3 shows an arrangement relationship of each component when the motor of the driving force transmission mechanism shown in FIG. 2 is reversed. It is assumed that the rotation direction of the motor that transmits the driving force to the drive gear 231 is changed and the drive gear 231 rotates in the reverse direction as indicated by an arrow 251. In this case, the feed roller gear 233 also rotates in the reverse direction as shown by the arrow 252 in conjunction with it.

  The planetary gear 236 meshed with the drive gear 231 by the planetary arm 235 also rotates in the reverse direction as indicated by the arrow 253. Further, the planetary arm 235 rotates in the direction of the arrow 254 in accordance with the change in the rotation direction of the drive gear 231 due to the load of the coil spring that has entered the planetary gear 236. Thereby, the planetary gear 236 releases the meshing with the separation roller gear 237, and this time meshes with the inner gear 238U of the two-stage gear 238. Then, the planetary gear 236 rotates in the reverse direction as indicated by the arrow 253, and accordingly, the two-stage gear 238 rotates in the direction indicated by the arrow 244. The rotation direction of the two-stage gear 238 is the same normal rotation direction as the direction in FIG.

  However, since the planetary gear 236 has changed the engagement destination from the separation roller gear 237, the rotational speed of the two-stage gear 238 is increased by the ratio of the outer gear 238S ÷ the inner gear 238U. Since the separation roller gear 237 meshes with the large-diameter outer gear 238S, the separation roller gear 237 similarly rotates in the forward rotation direction indicated by the arrow 221. The rotational speed of the separation roller gear 237 is increased by the amount of change described above, similarly to the two-stage gear 238. Thereby, as shown in FIG. 3, the peripheral speed of the separation roller 204 (FIG. 1) when the drive gear 231 is reversed is set to be substantially the same as the peripheral speed of the feed roller 211 (FIG. 1). This is to prevent a paper jam from occurring in the apparatus main body 201 (FIG. 1) due to a difference in feeding speed when the original is conveyed by the double-sided reading apparatus 200.

  The driving force transmission mechanism 230 has been described above. This is based on the assumption that the feed roller gear 233 and the feed roller 211, and the separation roller gear 237 and the separation roller 204 are directly connected to each other. is there. When a transmission system such as another gear is interposed between them, the number of teeth of the feed roller gear 233, the separation roller gear 237, and the two-stage gear 238 may naturally differ from the relationship described above.

  Further, in the driving force transmission mechanism 230 shown in FIGS. 2 and 3, the feed roller gear 233 and the separation roller gear 237 always rotate when the drive gear 231 connected to the motor rotates, so that the feed roller 211 shown in FIG. It seems that the separation roller 204 also always rotates. However, it is possible to control on / off of the driving of the separation roller 204 by arranging a means for turning on / off a transmission system such as an electromagnetic clutch (not shown) between the separation roller gear 237 and the separation roller 204. The rotation of the separation roller gear 237 can be stopped by devising the planetary arm 235 shown in FIGS. 2 and 3 to be positioned at the intermediate point in these drawings.

  Next, how images are read by the double-sided reading device 200 having the above configuration will be described in order.

  FIG. 4 shows how the originals stacked on the original supply tray are sent out. As shown in FIG. 4, it is assumed that a plurality of documents 203 are set on the document supply tray 202. The rubber plate 205 is disposed such that its surface forms a predetermined acute angle with respect to the original 203. Therefore, as the plurality of originals 203 set on the original supply tray 202 are arranged in the lower layer, the leading ends of the originals 203 are arranged so as to be shifted step by step on the downstream side of the rubber plate 205. Further, the document presence / absence sensor 206 detects that “there is a document” by the actuator being pushed by these documents 203.

  When the separation roller 204 rotates in the arrow 221 direction in this state, only the lowermost document 203L in contact with the document supply tray 202 is separated from the remaining documents and sent out in the downstream direction indicated by the arrow 224. The fed document 203 is detected by rotating the actuator of the document front / rear edge detection sensor 220 by a predetermined angle as shown in the figure. In this state, the document 203 is conveyed between the reading device 208 and the feed roller 211 in the direction of the arrow 224, and the reading of the image by the reading unit 209 arranged in the main scanning direction is performed in units of lines. The document 203 whose image has been read is transported downstream in the first horizontal transport path 212. Then, the document is discharged from the document discharge port 213 to a discharge tray (not shown) outside the apparatus main body 201. As described above, an image is read on one side of the original 203.

  FIG. 5 shows a state in which reading has started for a document having a relatively short length in the conveyance direction, and FIG. 6 shows a state in which the trailing edge of the document has reached the vicinity of the feed roller. Represents. In FIGS. 5 and 6, only one corresponding original 203 is shown for easy understanding.

  In the state shown in FIG. 5, the lowermost document 203 </ b> L being read is conveyed, and the separation roller 204 and the feed roller 211 both rotate forward as indicated by arrows 221 and 234 (the document 203 </ b> L is downstream as indicated by the arrow 224). The direction of conveyance in the direction). At this time, both the document presence / absence sensor 206 and the document front / rear edge detection sensor 220 detect the document 203L. When the feeding of the document 203L proceeds and the trailing edge passes through the document presence / absence sensor 206, the driving of the separation roller 204 is stopped if no remaining document is set on the document supply tray 202. As described below, the driving of the separation roller 204 may be stopped when the leading edge / rear edge detection sensor 220 detects the trailing edge of the document 203L.

  The conveyance state shown in FIG. 6 represents the time point when the image reading of the lowermost document 203L is completed. The time when the reading of the document 203L is completed can be determined as the time when the trailing edge of the document 203L is detected by the document leading edge / rear edge detection sensor 220, or the time when a predetermined time has elapsed from this time. At this point in time when the image reading is finished, the double-sided reading device 200 temporarily stops the driving of the feed roller 211. A control unit (not shown) determines whether the reading of the other side of the original 203L is continued or whether the reading operation is to be ended at this point when the reading of one side is completed.

  If all the reading operations are to be ended, the feed roller 211 is again driven in the normal rotation direction indicated by the arrow 234 in FIG. 5 for a predetermined time, and the document 203L is discharged onto the discharge tray. If the control unit has determined that only one side of the original 203L is read before the end of reading the image, the feed roller 211 is not temporarily stopped to continue the conveyance until the discharge is completed. You may make it perform. Such control can be realized, for example, by executing a CPU (Central Processing Unit) provided in a control unit (not shown) of the double-sided reading apparatus 200 using a predetermined control program.

  When only one side of the original 203L is read in this way and another original is set on the original supply tray 202, the image is read with the next original 203 being rolled by the separation roller 204. Of course, it is sent to the feed roller 211. The direction of the actuator of the document presence / absence sensor 206 differs depending on whether or not the next document to be sent out is set on the document supply tray 202. FIG. 6 shows these two states for the actuator of the document presence / absence sensor 206.

  Next, a case where an image on the other side of the original 203L is read will be described. When reading on both sides of the original 203L is performed in this way, the control unit starts reverse rotation of the feed roller 211 when reading of one side shown in FIG. Here, it becomes a problem whether the original 203L has a length necessary to reverse through the conveyance path described below. In this regard, the document 203L can detect the time required for the leading and trailing edges of the document 203L to pass by the document leading / tailing sensor 220. Therefore, the control unit described above can easily determine whether the document 203L has a length necessary for reversal using the difference between the detection times and the conveyance speed of the document 203L. Further, it is also a condition that no document is set other than the document 203L. When the document presence / absence sensor 206 detects another document, the duplex reading operation cannot be performed.

  FIG. 7 shows a state in which the document is conveyed in the reverse direction by the reverse rotation of the feed roller. When the feed roller 211 rotates in the reverse direction as indicated by the arrow 252, the separation roller 204 also rotates in the direction indicated by the arrow 221 at the same conveying speed as described with reference to FIG. In this state, the document 203L is conveyed upstream of the first horizontal conveyance path 212 as indicated by an arrow 256. When the leading end reaches the vicinity of the lower end portion of the document supply tray 202, it enters the second horizontal conveyance path 214 sandwiched between the upper guide portion 202A and the lower guide plate 215. The original 203L is guided and conveyed between the separation roller 204 that rotates in the direction of the arrow 221 and the guide belt 217 that is in sliding contact with the separation roller 204, and the leading end of the original 203L contacts the rubber plate 205.

  At this time, no document is set on the document supply tray 202. Assuming that an original is set on the original supply tray 202, when the separation roller 204 conveys the original 203L in the reverse direction by the guide belt 217, the original set on the original supply tray 202 becomes the second sheet and the rubber plate 205. This is because a problem of passing through the nip region of the separation roller 204 occurs.

  FIG. 8 shows a state in which the document reversed by the separation roller as described above is conveyed to the image reading position. The feed roller 211 is indicated by an arrow 234 after the leading edge of the original 203L is detected by the leading / leading edge detection sensor 220 until the leading edge reaches the contact point between the feed roller 211 and the reading unit 209. Switch the direction of rotation to the forward direction. However, when the leading edge of the document is detected by the leading and trailing edge detection sensor 220, if the trailing edge of the document is still at the contact point between the feed roller and the reading unit 209, the forward rotation direction is maintained until the trailing edge of the document is removed. Delay switching to. This switching control is determined from the transport length when one side is read. Further, the timing for switching to normal rotation after detecting the leading edge by the leading edge / rear edge detection sensor 220 can be set to any time as long as the leading edge of the document does not reach the contact point between the feed roller 211 and the reading unit 209. It is. As control classification based on the document length, it is possible to perform reverse reading only of a document that is longer than the minimum document length that can be read at the time of reversal and less than the maximum document length. Although the reading can be performed in this reading section, there is a section of the document length for which it is necessary to delay the reverse timing of the feed roller 211. In order to simplify the control of the control unit, if the default of the reversal timing of the feed roller 211 is set to the maximum document length, the reversal switching timing according to the document length is not necessary.

  Due to the forward rotation of the feed roller 211, the inverted original 203L passes over the reading unit 209, and the image is read. Thereafter, as described with reference to FIG. 6, the document 203 </ b> L having been read on both sides is discharged to the discharge tray outside the apparatus main body 201 by the normal rotation of the feed roller 211. When it is better to reverse the discharge surface of the original 203L, the original 203L that has been read on both sides is reversed again using the feed roller 211 and the separation roller 204, and then discharged onto the discharge tray. Is also possible.

  Further, as apparent from the above description, in the double-sided reading apparatus 200 of the present embodiment, when both sides are automatically read, there is an upper limit on the length of the original 203L in the conveyance direction. In order to automatically reverse a longer document so that both sides can be read, the distance between the feed roller 211 and the separation roller 204 is widened to increase the folding distance, or as shown in FIG. A discharge roller may be provided on the further downstream side of the roller 211, and reverse running for reversing the document 203L may be performed from this position.

  According to the double-sided reading device 200 of the present embodiment described above, the double-sided reading function can be realized using two drive rollers, that is, the feed roller 211 and the separation roller 204. Thereby, an inexpensive and compact double-sided reading device 200 can be realized. In addition, according to the present embodiment, the conventional high-performance double-sided reading device can perform double-sided reading of a small-size document that is difficult to be realized due to the long distance between the conveying rollers.

  <First Modification of Invention>

  FIG. 9 shows a first modification of the embodiment described above. 9, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In the double-sided reading device 200 </ b> A of the first modification, the first to third pinch rollers 216 _{1 to} 216 ₃ are spaced apart in the circumferential direction of the separation roller 204 in order to form a reversing path for the original 203. Arranged. Further, between the first to third pinch rollers 216 _{1 to} 216 ₃ , first and second document guides 301 ₁ and 301 ₂ that respectively constitute a part of a cylinder having a slightly larger diameter than the separation roller 204. Is arranged.

In this modified example, a state in which the feed roller 211 starts to rotate in the reverse direction indicated by the arrow 252 and the document 203 is transported upstream along the first horizontal transport path 212 will be described. The point that the leading edge of the original 203 enters the second horizontal conveyance path 214 from the first horizontal conveyance path 212 is the same as in the previous embodiment. After that, the document 203 passes between the separation roller 204 that rotates in the direction of the arrow 221 and the first pinch roller 216 ₁ that is in rolling contact with the separation roller 204 to obtain a conveyance force, and is guided by the _first document guide 3011 to the _first . It is conveyed to the position of the _second pinch roller 216 ₂ . Then, the paper passes between the separation roller 204 and the second pinch roller 216 ₂ that is in rolling contact with the separation roller 204 to obtain a conveyance force in the same manner, and is guided by the _second document guide 3012 to reach the third pinch roller 216 ₃ . It is transported to the position. One end of the guide portion 202B is disposed in the vicinity of the third pinch roller 216 ₃ . Therefore, the leading end of the original 203 is guided by the guide portion 202B, reaches the nip region between the rubber plate 205 and the separation roller 204, and passes through this to be in a reversed conveyance state as shown in FIG. Thereafter, the same conveyance as in the previous embodiment is performed, and thus the description thereof is omitted.

According to the first modification, by leaving a detachable first and second document guides 301 _1, 301 _2, it is possible to easily deal with a paper jam during inversion of the document 203. Even if the separation roller 204 has a relatively small diameter, a path for reversal can be easily configured.

  <Second Modification of Invention>

  FIG. 10 shows a second modification of the previous embodiment. 10, the same parts as those in FIG. 1 or FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In the second modification of the double-sided reading device 200B, it constitutes a path for inverting the document 203 in the first pinch roller 216 ₁ and the guide portion 202C. Here, the guide portion 202C is formed such that the guide portion 202C having a curved shape so as to draw a semicircle along the surface of the separation roller 204 from the upper end position of the opening for the separation roller 204 of the document supply tray 202 corresponds to the roller surface. They are arranged while maintaining a slight distance, the first pinch roller 216 ₁ to the end point is located.

  In the second modification, the number of pinch rollers 216 is reduced as compared with the double-sided reading device 200A of the first modification shown in FIG. For this reason, it is necessary to devise such that the minimum required length in the conveyance direction of the original 203 is longer than that in the first modification, or the interval between the separation roller 204 and the feed roller 211 is made shorter.

  However, since the number of pinch rollers 216 is reduced, the cost of the double-sided reading apparatus 200A can be reduced by this amount, and the probability of occurrence of a paper jam caused by the pinch rollers 216 can be reduced.

  Note that the pinch roller 216 constituting the path for reversing the document 203 may be provided at two places unlike the first or second modification described above, or at four places or more. Also good. In the second modification, the guide 203 for reversing the document 203 is constituted by the guide portion 202C and the lower guide plate 215, but these may be integrally formed.

  <Third Modification of the Invention>

  FIG. 11 shows a third modification of the previous embodiment. 11, the same parts as those in FIG. 1 or FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In the double-sided reading device 200C of the third modified example, the minimum required length limitation in the conveyance direction of the original 203 by the double-sided reading device 200B of the second modified example shown in FIG. 10 is relaxed. Therefore, in the double-sided reading device 200C of the third modified example, in addition to the _first pinch roller 2161, the fourth pinch roller that is in rolling contact with the roller surface at a position closest to the document supply tray 202 in the separation roller 204. 216 ₄ is newly arranged. The first and fourth pinch rollers 216 ₁ and 216 ₄ are connected to each other by first and second U-shaped guide plates 311 and 312 that maintain a predetermined distance from each other.

In the double-sided reading device 200C, the length of the U-shaped conveyance path 313 formed by the first and second U-shaped guide plates 311 and 312, that is, the first and fourth pinch rollers 216 ₁ and 216 _4. Is the same as the minimum required length in the conveyance direction of the document 203. The maximum length of the original 203 in the conveyance direction is obtained by subtracting the length of the arc of the separation roller 204 between the first and fourth pinch rollers 216 ₁ and 216 ₄ from the length of the U-shaped conveyance path 313. It is extended from the double-sided reading device 200B of the second modification by the increment.

  <Fourth Modification of the Invention>

  FIG. 12 shows a fourth modification of the previous embodiment. In FIG. 12, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In the double-sided reading apparatus 200D of the fourth modified example, the reading device 208D is a reading device using a CCD, unlike the reading device using the CIS. Inside the housing 321 constituting the reading device 208D, a pinch roller 322 that is in rolling contact with the feed roller 211 is disposed. In addition, a transparent plate 323 made of plastic or the like is fitted into the opening at the top of the housing 321 so that the light emitted from the light source 324 disposed inside is irradiated to the reading position 325 of the document 203. .

  The reflected light 326 of the original 203 obtained from the reading position 325 is reflected by the first mirror 327 disposed at the bottom in the housing 321. Second and third mirrors 328 and 329 are arranged on two side surfaces in the housing 321 so as to face each other. The reflected light 326 from the original 203 reflected by the first mirror 327 is reflected back by a plurality of diffraction by the second and third mirrors 328 and 329 in order to increase the optical path length. Then, the light enters the optical lens 331 disposed in the vicinity of the side surface of the housing 321 so as to form an optical image on the one-dimensional image sensor 332. The one-dimensional image sensor 332 reads an image line by line in the main scanning direction orthogonal to the conveyance direction (sub-scanning direction) of the document 203, and optical image information is corrected by an image processing circuit (not shown).

  According to the fourth modified example of the present invention, since the pinch roller 322 is built in the reading device 208D, the load when the feed roller 211 is rotated is reduced. Further, since it is not necessary to press the original at the reading position, the width of the roller can be reduced with respect to the original to be read. Since these reduce the load when the document is conveyed, it is possible to contribute to the reduction of the driving load of the entire duplex reading apparatus 200D.

  <Fifth Modification of Invention>

  FIG. 13 shows a fifth modification of the previous embodiment. In FIG. 13, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In the double-sided reading device 200E of the fifth modified example, a document supply roller 341 and a pinch roller 342 that is in contact with the document supply roller 341 are disposed immediately downstream of the document presence / absence sensor 206 of the document supply tray 202. The document supply roller 341 is substantially the same as the separation roller 204 in the previous embodiment, and the first to third pinch rollers 216 _{1 to} 216 ₃ and the guide belt 217 are disposed around the document supply roller 341. Are the same. The document supply roller 341 is for cooperating with the pinch roller 342 to convey documents set on the document supply tray 202 one by one by detection of the document presence / absence sensor 206, and separates the documents one by one. The name has been changed because it has no function.

  The double-sided reading device 200E is different from the double-sided reading device 200 of the embodiment in that it does not have an automatic supply function for automatically sending originals one by one to an image reading position, but there are no other changes. . Therefore, when both sides of a document are instructed to be scanned, as described in the previous embodiment, the document that has been scanned on one side enters the second horizontal conveyance path 214 and is fed to the document. The paper passes between the paper roller 341 and the guide belt 217 and reverses. Then, the other side is read by passing between the reading device 208 and the feed roller 211.

  Note that the pinch roller 342 that is in rolling contact with the document supply roller 341 is changed to a roller that rotates in a direction that pushes back the document upstream except when the document is fed out or that stops against the drive of the document supply roller 341. Therefore, it is natural that an automatic document supply function can be provided.

  In the embodiment and each modification described above, the reading device 208 is pressed against the feed roller 211 by the pressing spring 219, but the present invention is not limited to this. For example, a platen glass (not shown) may be disposed at a predetermined horizontal position in the apparatus main body 201, and the feed roller 211 may be brought into rolling contact with the platen glass by its own weight. In this case, the document 203 passes between the platen glass and the feed roller 211, and an image is read by an optical system and a reading element (not shown) arranged below the platen glass.

  In the embodiment and each modification of the present invention, the document is reversed using a cylindrical roller such as the separation roller 204 or the document supply roller 341. For example, the document is fed by an endless belt, Of course, inversion may be performed.

  In the previous embodiment, the description was made with reference to FIG. 7 in a situation where only one document 203 is set on the document supply tray 202. However, depending on the situation, it is possible that the separation roller 204 reverses and sends out the original 203L that has been sent out in a state where the next original 203 remains on the original supply tray 202. Next, this will be described as a sixth modification.

    <Sixth Modification of Invention>

  FIG. 14 shows a main part of the configuration of a double-sided reading apparatus according to a sixth modification of the present invention. In the double-sided reading device 200F of the sixth modified example, the same parts as those in FIG. 10 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In this double-sided reading device 200F, the upper guide portion 202A in the double-sided reading device 200B of the second modified example shown in FIG. 10 extends to the vicinity of the upper part of the separation roller 204 in a non-contact state with the roller surface. The paper guide portion 202E is disposed. Further, in FIG. 10 the guide portion 202C and the lower guide plate 215 by integrating the second paper guide portion 202F having a shape removing the first pinch roller 216 ₁ from the duplex scanning apparatus 200B of FIG. 10, a first The paper guide unit 202E is disposed outside the paper guide unit 202E at a predetermined interval. In addition, the rotation of the separation roller 204 and the rotation of the feed roller 211 are performed in the double-sided reading apparatus 200F by using the means for turning on / off the transmission system such as an electromagnetic clutch mentioned in the section described above for the driving force transmission mechanism 230. It can be controlled independently.

  In the double-sided reading device 200F configured as described above, when the feed roller 211 rotates in the reverse direction as indicated by the arrow 252, the document 203L passes between the first and second paper guide portions 202E and 202F, and the separation roller It is conveyed toward the place of contact between 204 and the rubber plate 205. At this time, the separation roller 204 stops rotating. The original 203L can smoothly reach the position where the separation roller 204 and the rubber plate 205 are in contact with each other even in this state where the separation roller 204 is stopped due to the presence of the first paper guide portion 202E.

  At this time, one or more originals 203 are stacked on the original supply tray 202, and the leading ends of the originals 203 are in contact with the lower surface of the inclined rubber plate 205 so that a step is generated one by one. The document 203 </ b> L that has traveled to a position just before the contact point between the separation roller 204 and the rubber plate 205 proceeds so as to push up the document 203 from the lower side of the document 203 stacked on the document supply tray 202. As a result, it reaches the place closest to the contact place between the separation roller 204 and the rubber plate 205.

  As a premise of this, in the double-sided reading device 200F of the sixth modified example, the lower limit of the length in the conveyance direction of the document 203L is from the contact location of the separation roller 204 and the rubber plate 205 to the contact location of the feed roller 211 and the reading device 208. It is necessary to be longer than the length of the transport path. Here, the conveyance path passes through the first and second paper guide portions 202E and 202F. Further, the length of the original 203L in the conveyance direction is less than the length from the contact position of the feed roller 211 and the reading device 208 to the position of contact of the feed roller 211 and the reading device 208 again via this conveyance path. It will be necessary.

  When the original 203L sent from the contact position between the feed roller 211 and the reading device 208 via the first and second paper guide portions 202E and 202F is conveyed to the contact position between the separation roller 204 and the rubber plate 205. The separation roller 204 starts to rotate in the arrow 221 direction. As a result, the original 203L is conveyed in the direction of the feed roller 211 by the separation roller 204. As the operation at this time, the document conveyance speed of the separation roller 204 when the feed roller 211 rotates in the reverse direction is the same as that of the feed roller 211, and therefore, document jamming due to the difference in the roller conveyance speed does not occur. Subsequently, at the time when the leading edge of the document 203L is detected by the document leading edge / rear edge detection sensor 220, the trailing edge of the document 203L may be missing from the feed roller 211 and the document reading, or may not be missing yet. In the same manner as described in the previous embodiment with reference to FIG. 8, the rotation switching timing of the feed roller 211 is determined based on the conveyance length at the time of reading one side of the document and changed. That is, when the transport length is longer than the length that reaches the document leading edge / rear edge detection sensor 220 via the first and second paper guide portions 202E and 202F from the contact position between the feed roller 211 and the reading device 208, the leading edge After the detection, until the trailing edge of the document 203L is completely removed from the feed roller 211, the switching time of the feed roller in the normal rotation direction is delayed. If the conveyance length is short, the feed roller 211 is switched at a predetermined time. After the original 203L is sent to the contact position between the feed roller 211 and the reading device 208, the image information on the second side is read from the original 203L. The document 203L that has been read is started to be discharged from the document discharge port 213.

  When the rear end of the original 203L moves away from the contact position between the separation roller 204 and the rubber plate 205, the lowermost original 203 stacked on the original supply tray 202 moves in the direction of the feed roller 211 as the separation roller 204 rotates. Be transported. As a result, the image information on the first side of the original 203 is read. In the same manner, the image information on the second side of the original 203 is also read by the reverse rotation control of the feed roller 211.

  As described above, the double-sided reading device 200F according to the sixth modification can continuously read both sides of the document regardless of the number of documents 203 set on the document supply tray 202.

It is explanatory drawing showing the principal part of the structure of the double-sided reader in embodiment of this invention. FIG. 3 is a principle diagram of a driving force transmission mechanism when a driving roller is rotating forward in the present embodiment. It is a principle diagram of the driving force transmission mechanism when the driving roller is reversely rotated in the present embodiment. FIG. 6 is an explanatory diagram showing a state in which documents stacked on a document supply tray are sent out in the present embodiment. FIG. 4 is an explanatory diagram of an apparatus showing a state in which the reading of a document having a relatively short length in the conveyance direction has not started so much in this embodiment. FIG. 3 is an explanatory diagram of an apparatus showing a state in which the trailing edge of a document reaches the vicinity of a feed roller in the present embodiment. It is explanatory drawing of the apparatus which showed the state in which the original document is conveyed in the reverse direction in this Embodiment. FIG. 4 is an explanatory diagram of an apparatus showing a state where a document inverted by a separation roller is conveyed to an image reading position in the present embodiment. It is explanatory drawing showing the principal part of the structure of the double-sided reader in the 1st modification of this invention. It is explanatory drawing showing the principal part of the structure of the double-sided reader in the 2nd modification of this invention. It is explanatory drawing showing the principal part of the structure of the double-sided reader in the 3rd modification of this invention. It is explanatory drawing showing the principal part of the structure of the double-sided reader in the 4th modification of this invention. It is explanatory drawing showing the principal part of the structure of the double-sided reader in the 5th modification of this invention. It is explanatory drawing showing the principal part of the structure of the double-sided reader in the 6th modification of this invention. It is explanatory drawing showing the principal part of the structure of the double-sided reader by related technology. It is explanatory drawing which showed the motion of two sensors in the vicinity of the separation roller of a double-sided reading apparatus by related technology. It is explanatory drawing showing a mode that the document laminated | stacked on the document supply tray by related technology is sent out. It is the perspective view which showed the one-way mechanism used by related technology. It is explanatory drawing which shows the reading state of an image when the length of a manuscript is comparatively long with related technology.

Explanation of symbols

200, 200A to 200E Double-sided reading apparatus 201 Main body 202 Document supply tray 202A Upper guide section 202B, 202C Guide section 202E First paper guide section 202F Second paper guide section 203, 203L Document 204 Separating roller 205 Rubber plate 206 Document Presence sensor 208 Reading device 209 Reading unit 211 Feed roller 212 First horizontal conveyance path 214 Second horizontal conveyance path 215 Lower guide plate 216, 322, 342 Pinch roller 217 Guide belt 220 Document front / rear edge detection sensor 301 Document guide 311 and 312 U-shaped guide plate 313 U-shaped conveyance path 328 Second mirror 329 Third mirror 331 Optical lens 332 One-dimensional image sensor 341 Document supply roller

Claims (8)

A document supply tray having a tray surface inclined downward at a predetermined angle to enable stacking of a plurality of documents;
A separation roller that is rotatably arranged in such a manner that a part of its outer periphery protrudes upward from a virtual surface extending downward from the tray surface of the document supply tray;
A surface inclined at an inclination angle larger than the inclination angle of the tray surface, and this surface is brought into rolling contact with a part of the outer periphery of the separation roller at a predetermined rolling contact point and above the rolling contact point. A plate-like member having a shape obtained by extending the surface by a predetermined length;
Separation roller driving means for rotating the separation roller in a predetermined direction when the document is sent out from the rolling contact portion to a downstream conveyance path;
A feed roller disposed in a conveyance path downstream from the rolling contact point;
An image reading means that is arranged at a position where it comes into rolling contact with the feed roller, and sequentially reads the image information on the surface opposite to the rolling contact surface when the document is conveyed downstream by the feed roller,
A feed roller driving means for rotating the feed roller by switching to one of two directions, a direction of conveying the document downstream and a direction of conveying the document in the opposite direction;
When it is instructed to read image information on the other side of the document after reading the image information on one side of the document by the image reading unit, the document is switched in the reverse direction by the feed roller driving unit. Feed roller drive control means that starts conveying and moves the leading edge of the document so as to reach the position immediately before the rolling contact point along the outer periphery of the separation roller from below the separation roller. A double-sided document reading device comprising: 2. The plate-like member is made of a predetermined elastic material, and the originals stacked on the original supply tray are separated and sent one by one from the rolling contact portion by the rotation of the separation roller. Document double-sided reading device. 3. A document double-sided reading device according to claim 2, further comprising peripheral surface guide means for guiding the movement of the document along the outer periphery of the separation roller . The circumferential surface guide means includes a circumferential surface between the rolling contact pinch rollers of the separating roller, and a guide plate for along the conveying direction of the document passing between the peripheral surface of the pinch roller and the separation roller to the circumferential surface The document double-sided reading device according to claim 3, comprising at least. It said separation roller, according to claim 2, characterized in that it is arranged a detour guide means for guiding the movement of the document along a path to be returns detour peripheral surface from away once from the peripheral surface of the separation roller The document double-sided reading device described. The circumferential surface guide means Duplex reader according to claim 3, characterized in that it is constituted by an endless belt-like member. A pinch roller that is in rolling contact with the feed roller is provided, and the pinch roller and the image reading unit are accommodated in a single housing that is given a habit of being in pressure contact with a feed roller that is rotatably disposed at a fixed position. The document double-sided reading device according to claim 1.   The image reading means includes a light source that irradiates a reading position of the document disposed in the casing, and a folding optical system that refracts the reflected light from the reading position by the light source by a plurality of mirrors disposed in the casing. And an optical system for forming an image on a predetermined surface by entering a light beam that has passed through the folded optical system, and an image reading element disposed at an imaging position of the optical system. The document double-sided reading device described.

Images