WO2023276807A1

WO2023276807A1 - Document conveying device

Info

Publication number: WO2023276807A1
Application number: PCT/JP2022/024831
Authority: WO
Inventors: 浩次藤井; 卓朗村田; 昌弘中尾; 太朗倉橋; 翔太浦▲瀬▼; 義多賀所; 貴文中川; 寛史萩原
Original assignee: 京セラドキュメントソリューションズ株式会社
Priority date: 2021-06-28
Filing date: 2022-06-22
Publication date: 2023-01-05

Abstract

A document conveying device comprising: a supplied document detecting sensor (123) which detects a document upon a supply tray (43); a discharge tray (45) which is provided below the supply tray (43); a discharged document detecting sensor (127) which detects the document upon the discharge tray (45); and a raising/lowering mechanism (125) which raises and lowers the supply tray (43) between an upper limit position at which the document is pushed against a feed roller (103) and the feed roller (103) is raised to a prescribed supply height and a lower limit position which is below and apart from the feed roller (103), wherein when it is determined, on the basis of detection results from the supplied document detecting sensor (123), that the document has been removed from the supply tray (43) while the device is in standby, the raising/lowering mechanism (125) lowers the supply tray (43) to a prescribed position in accordance with detection results from the discharged document detecting sensor (127).

Description

document feeder

The present invention relates to a document conveying device that conveys a document to a document reading device.

In recent years, with the conversion of various documents (original documents) into electronic data in response to the trend toward paperless operations, improvements in the quality and functionality required of document feeders of multifunction peripherals (MFPs) are being pursued. One of the required functions is high-speed reading of large-capacity originals. This demand is met by increasing the reading speed or increasing the stacking amount of originals. Furthermore, in order to ensure the reliability of the read data, it is equipped with a sensor that detects double feeding to prevent skipping of documents and functions to protect documents in the event of a paper jam.

For example, in Japanese Patent Laid-Open No. 2002-100000, a lifting means for lifting a paper feed tray and a lifting control means for lifting the paper feed tray in accordance with feeding out of a document from the paper feed tray are provided. A document feeder (corresponding to a document feeder) has been proposed that is configured to move up and down by the same amount as the tray moves up and down. Specifically, the paper feed tray is positioned at the lowest position based on a detection signal from a lower limit sensor that detects that the paper feed tray has reached the lower limit position with no document placed thereon, while the document is placed thereon. When the presence/absence sensor detects this, the paper feed tray is raised based on this detection signal until the uppermost document comes into contact with the pickup roller.

JP-A-2005-8283

In the document feeder described in Patent Document 1, when the presence or absence of documents is detected by the document presence/absence sensor, the paper feed tray rises until the uppermost document comes into contact with the pickup roller. . Then, for example, when it is desired to add a document, after the document is once taken out from the paper feed tray, the paper feed tray remains raised. In this case, the amount of documents that can be stacked on the paper feed tray is reduced.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a document conveying apparatus capable of increasing the amount of next document placed on the paper feed tray even when the document is taken out from the paper feed tray. .

In order to achieve the above object, a document conveying apparatus according to an embodiment of the present invention includes: a paper feed tray on which documents are stacked and arranged to be movable up and down; A document detection sensor, a discharge tray provided below the paper feed tray, a discharged document detection sensor for detecting the presence or absence of the document on the discharge tray, and the document conveyed from the paper feed tray toward a reading position. a transport path through which the document is transported from the reading position toward an output port; A delivery roller for feeding, an upper limit position where the loaded document is pressed against the delivery roller to raise the delivery roller to a predetermined paper feed height, and a lower limit position spaced downward from the delivery roller. an elevating mechanism for elevating the paper feed tray between them, wherein the document is taken out from the paper feed tray based on the detection result of the fed document detection sensor during standby when the document transport operation is not executed. When this is determined, the lifting mechanism lowers the paper feed tray to a predetermined position according to the detection result of the discharged original detection sensor.

A document conveying apparatus according to another embodiment of the present invention includes a paper feed tray on which documents are stacked and which can be raised and lowered; a fed document detection sensor for detecting the presence or absence of the document on the paper feed tray; an ejection tray provided below the paper feed tray, an ejected document detection sensor that detects the presence or absence of the document on the ejection tray, and a transport path through which the document is transported from the paper feed tray toward a reading position; an ejection path through which the document is transported from the reading position toward an ejection port; and a delivery roller that rotates in contact with the document stacked on the paper feed tray to feed the document into the transport path. a lower limit position spaced downward from the delivery roller and a lower limit position spaced apart from the delivery roller; and a lifting mechanism for lifting and lowering the paper feed tray, and after the operation of conveying the document is completed, the lifting mechanism lowers the paper feed tray to a predetermined position according to the detection result of the discharged document detection sensor. Characterized by

According to the present invention, by lowering the paper feed tray when documents are taken out from the paper feed tray during standby, the amount of documents to be placed next on the paper feed tray can be increased.

1 is a front view schematically showing a multi-function machine provided with a document conveying device according to one embodiment of the present invention; FIG. 1 is a perspective view showing a document conveying device (with an outer cover removed) according to an embodiment of the present invention; FIG. 1 is a cross-sectional view showing a document conveying device according to one embodiment of the present invention; FIG. FIG. 2 is a front view showing an elevating mechanism for a paper feed tray in the document conveying device according to one embodiment of the present invention; 3 is a perspective view showing an arm of an elevating mechanism for a paper feed tray in the document conveying device according to one embodiment of the present invention; FIG. FIG. 10 is a perspective view showing a lower limit sensor of the lifting mechanism for the paper feed tray in the document conveying apparatus according to the embodiment of the present invention; 3 is a block diagram showing a control section of the document conveying device according to one embodiment of the present invention; FIG. 5 is a flowchart showing a first example of document transport processing in the document transport apparatus according to one embodiment of the present invention; FIG. 10 is a cross-sectional view showing a document conveying device according to another example of one embodiment of the present invention (with the discharge opening moved to the lower limit); FIG. 10 is a cross-sectional view showing a document conveying device (with the discharge opening moved to the upper limit) according to another example of one embodiment of the present invention; 9 is a flow chart showing a second example of document transport processing in the document transport apparatus according to one embodiment of the present invention.

A multi-function machine including a document conveying device and a document reading device according to an embodiment of the present invention will be described below with reference to the drawings.

The multi-function device 1 will be described with reference to FIG. FIG. 1 is a front view schematically showing the internal configuration of the multifunction machine 1. As shown in FIG. Fr, Rr, L, and R shown in each figure indicate the front side, rear side, left side, and right side of the multifunction machine 1, respectively.

The multifunction device 1 includes an image forming device 3, a document reading device 5, and a document conveying device 7. The image forming device 3 forms an image on a sheet based on the image of the document G read by the document reading device 5 . The document conveying device 7 conveys the document G to the document reading device 5 .

First, the image forming apparatus 3 will be briefly described. The image forming apparatus 3 includes a paper feeding section 11 , an image forming section 13 and a fixing section 15 . The paper feeding unit 11 feeds sheets accommodated in the paper feeding cassette 17 and conveys them to the conveying path 19 . The image forming unit 13 electrophotographically forms a toner image on the sheet conveyed along the conveying path 19 based on the image of the document G read by the document reading device 5 . The fixing device 15 fixes the toner image formed on the sheet to the sheet. The sheet on which the toner image is fixed is stacked on the discharge tray 21 .

Next, the document reading device 5 will be explained. The document reading device 5 includes a contact glass 31 on which a document G can be placed, and a scanner section 33 arranged below the contact glass 31 for reading an image of the document G placed. The scanner unit 33 includes a first carriage 35 and a second carriage 37 that interlock and move in a predetermined direction (horizontal direction), and an imaging unit 39 that is fixed at a predetermined position.

The first carriage 35 accommodates a light source 35a and a first mirror 35b. The first carriage 35 is movable rightward from a home position below the left end of the contact glass 31 . The second carriage 37 accommodates second and

third mirrors

37a and 37b. The second carriage 37 can move rightward under the first carriage 35 from a home position on the left side of the home position of the first carriage 35 .

The imaging unit 39 includes a CCD sensor 39a and an imaging lens 39b that forms an optical image on the CCD sensor 39a. The imaging unit 39 is fixed below the right end of the contact glass 31 at the same height as the third mirror 37 b of the second carriage 37 .

When reading the document G placed on the contact glass 31, the first carriage 35 moves rightward from the home position at a predetermined speed while emitting light from the light source 35a, and the second carriage 37 moves to the home position. , to the right at half the speed of the first carriage 35 . As a result, the G reading position of the original (the position where the light emitted from the light source 35a is reflected toward the contact glass 31 by the first mirror 35b of the first carriage 35) is moved, and the image of the entire surface of the original G is displayed. read. The light reflected by the document G is reflected to the left by the first mirror 35b, is further reflected by the second and

third mirrors

37a and 37b of the second carriage 37, and is imaged on the CCD sensor 39a by the imaging lens 39b. be done. The formed optical image is converted into an electrical signal and transmitted to the control unit 201 (see FIG. 7).

On the other hand, when reading a document G conveyed by the document conveying device 7, which will be described later, the first carriage 35 and the second carriage 37 are stopped at their home positions, and the document G conveyed to the reading position P is read. read the image. At the reading position P, the image of the entire surface of the document GG is read.

On the other hand, when reading a document conveyed by the document conveying device 7, which will be described later, the first carriage 35 and the second carriage 37 each stop at the home position and read the image of the document conveyed to the reading position. . As the original passes through the reading position, the image of the entire surface of the original is read.

Next, the document conveying device 7 will be described with reference to FIGS. 1, 2 and 3. FIG. 2 is a perspective view showing the document feeder 7 (with the outer cover 63 removed), and FIG. 3 is a sectional view showing the document feeder 7. As shown in FIG.

The document conveying device 7 includes a main body 41 (see FIGS. 2 and 3), a paper feed tray 43 on which a document G whose image is to be read is placed, and a paper feed tray 43 which is provided below the paper feed tray 43 so that the image can be read. A discharge tray 45 on which the document G is stacked, a transport section 47 in which the document G is transported from the paper feed tray 43 to the discharge tray 45 via the reading position P, and a document from the paper feed tray 43 to the transport section 47. and a delivery unit 49 for feeding G. As described above, the reading position P is a state in which the first carriage 35 and the second carriage 37 of the document reading device 5 are stopped at the home position, and the light emitted from the light source 35a of the first carriage 35 reaches the first mirror 35b. is a position reflected on the contact glass 31 by .

As shown in FIG. 2 , the main body 41 includes a rectangular bottom plate 51 , a front wall 53 standing along the left half of the front edge of the bottom plate 51 , and a wall extending along the entire rear edge of the bottom plate 51 . and an upright rear wall 55 . Left and right rear corners of the body portion 41 are rotatably supported by the document reading device 5 . By rotating the body portion 41 upward, the original can be placed on the contact glass 31 of the original reading device 5 and the original can be taken out from the contact glass 31 . Further, when the body portion 41 is rotated downward, the document on the contact glass 31 is pressed against the contact glass 31 by the bottom plate 51 and positioned.

Next, the transport section 47 will be described. The conveying portion 47 has an inner guide 61 and an outer cover 63 that covers the upper surface and the left side surface of the inner guide 61, and is located on the bottom plate 51 of the main body portion 41 between the front wall 53 and the rear wall 55. is provided.

As shown in FIG. 3, the transport section 47 is provided with a transport path 69 leading from the receiving port 65 to the reading position P and a discharge path 73 extending from the reading position P to the discharge port 71 . A transport path 69 is formed between the outer cover 63 and the inner guide 61 . The discharge path 73 is disposed inside the inner guide 61 and formed between upper and lower plate-

like guide members

75 and 77 facing each other with a gap through which the document G can pass.

The transport path 69 is formed so as to extend substantially straight leftward from the receiving port 65 and then curve downward toward the reading position P. The discharge path 73 is formed to extend obliquely upward to the right from the reading position P toward the discharge port 71 . In this manner, the document G is transported from the receiving port 65 to the reading position P along the transport path 69, transported from the reading position P to the discharge port 71 along the discharge path 73, and passes through the reading position P. , the image of the document G is read by the document reading device 5 . In the following description, the terms "upstream side" and "downstream side" refer to the upstream side and the downstream side in the direction in which the document G is conveyed. The width direction is defined as the direction intersecting the conveying direction.

In the transport path 69, first to fourth transport roller pairs 81, 83, 85, 87 are arranged in order from the upstream side.

The first to fourth conveying roller pairs 81, 83, 85, 87 are arranged at predetermined intervals along the conveying direction. Each transport roller pair has a drive roller and a driven roller that rotates in contact with the drive roller. Each drive roller is supported by the inner guide 61 so as to be rotatable around a drive shaft parallel to the width direction. Each driven roller is rotatably supported by the outer cover 63 around a rotation axis parallel to the width direction.

An opening 51 a corresponding to the reading position P is formed in the bottom plate 51 of the main body 41 . A shading plate 91 is arranged in the inner guide 61 so as to face the opening 51a. Between the shading plate 91 and the contact glass 31 of the document reading device 5, there is a space through which the document G can pass. The shading plate 91 performs shading correction of the CCD sensor 39a.

A fifth transport roller pair 95 and a discharge roller pair 97 are arranged in order from the upstream side in the discharge path 73 .

The fifth conveying roller pair 95 is arranged downstream of the shading plate 91 and has a driving roller and a driven roller that rotates in contact with the driving roller. The drive roller is supported by the upper guide member 75 so as to be rotatable around a drive shaft parallel to the width direction. The driven roller is rotatably supported by the lower guide member 77 around a rotation axis parallel to the width direction.

The discharge roller pair 97 is arranged upstream of the discharge port 71 and has a drive roller and a driven roller that rotates in contact with the drive roller. The drive roller is supported by the upper guide member 75 so as to be rotatable around a drive shaft parallel to the width direction. The driven roller is rotatably supported by the lower guide member 77 around a rotation axis parallel to the width direction.

Next, the delivery portion 49 will be described. The feeding section 49 is arranged downstream of the receiving port 65 and includes a feeding roller 103 and a conveying belt 105 housed in a holder 101 , and an auxiliary roller 107 . The holder 101 has a box shape with an open bottom surface. A projecting piece 101a protrudes from the upper surface of the top plate of the holder 101 . The delivery roller 103 is arranged on the upstream side inside the holder 101 and is rotatably supported around a rotation axis parallel to the width direction. The conveying belt 105 is arranged inside the holder 101 on the downstream side of the feeding roller 103 and is wound around the driving roller 109 and the driven roller 111 . The driving roller 109 is arranged on the downstream side of the driven roller 111 and rotates about a driving shaft and a rotating shaft parallel to the width direction. As shown in FIG. 2, the holder 101 is arranged in the center in the width direction, and both ends of the driving shaft 109a of the driving roller 109 are rotatably supported by the front wall 53 and the rear wall 55 of the main body 41. there is A rear end of the drive shaft 109a is connected to a drive motor 113 (see FIG. 3).

A one-way clutch (not shown) is arranged between the drive shaft 109a and the holder 101. When the drive shaft 109a rotates counterclockwise in FIG. 3, the holder 101 swings upward around the drive shaft 109a together with the drive shaft 109a. On the other hand, the drive shaft 109a rotates with respect to the holder 101 when the drive shaft 109a rotates clockwise. As a result, the driving roller 109 rotates and the conveying belt 105 runs clockwise in FIG. Furthermore, the clockwise rotation of the drive shaft 109a is transmitted to the delivery roller 103 via a gear (not shown), and the delivery roller 103 rotates clockwise in FIG.

Further, the auxiliary roller 107 is arranged in the inner guide 61 so as to contact the lower running surface of the transport belt 105, and is rotatably supported around a rotation axis parallel to the width direction.

As described above, the holder 101 swings vertically around the drive shaft 109a. At the uppermost position where the holder 101 has swung upwards, the delivery roller 103 rises to a predetermined sheet feeding height. The holder 101 is supported by a stopper (not shown) at the lower limit position where the holder 101 swings downward. The conveying section 47 is provided with an upper limit position detection sensor 115 that detects that the holder 101 has risen to the upper limit position.

The upper limit position detection sensor 115 is, for example, a transmissive optical sensor. A transmissive optical sensor has a light emitting portion and a light receiving portion, outputs an on signal when an optical path formed between the light emitting portion and the light receiving portion is blocked, and outputs an off signal when the optical path is formed. Output. Upper limit position detection sensor 115 is supported by outer cover 63 above holder 101 . When the holder 101 rotates to the upper limit position, the projecting piece 101a enters between the light emitting portion and the light receiving portion of the upper limit position detection sensor 115 to block the optical path, and the upper limit position detection sensor 115 outputs an ON signal.

Next, the paper feed tray 43 and the discharge tray 45 will be described. The paper feed tray 43 is a plate-like member on which the maximum size document G can be placed. As shown in FIG. 2, the paper feed tray 43 supports a pair of side cursors 121 for positioning the placed document G in the width direction so as to be movable in the width direction.

Further, the paper feed tray 43 is provided with a fed document detection sensor 123 for detecting the presence or absence of the document G. The fed document detection sensor 123 is, for example, a reflective optical sensor having a light emitting portion and a light receiving portion. An opening is formed in the upper plate of the paper feed tray 43 at the end on the downstream side. The fed document detection sensor 123 is arranged below the opening. When the document G is placed on the paper feed tray 43, the document G reflects the light emitted from the light emitting portion through the opening. When the reflected light passes through the opening and is received by the light receiving portion, the fed document detection sensor 123 outputs an ON signal. On the other hand, when the original document G is not placed on the paper feed tray 43, the light emitted from the light emitting unit is not reflected by the original document G, so that it is not received by the light receiving unit, and the fed original detection sensor 123 outputs an OFF signal. to output

The paper feed tray 43 is arranged above the right half of the bottom plate 51 of the main body 41, and is tilted downward toward the receiving port 65. The paper feed tray 43 is vertically supported by a lifting mechanism 125 (see FIG. 4). there is The lifting mechanism 125 will be described later.

The discharge tray 45 is formed on the right half of the bottom plate 51 of the main body 41 . The discharge tray 45 is inclined upward from below the discharge port 71 toward the side (right side) away from the discharge port 71 .

The ejection tray 45 is equipped with an ejected document detection sensor 127 that detects the presence or absence of the document G. The discharged original detection sensor 127 is, for example, a reflective optical sensor having a light emitting portion and a light receiving portion. The upper plate of the discharge tray 45 is formed with an opening at the end on the upstream side. The discharged original detection sensor 127 is arranged below the opening. When the document G is placed on the discharge tray 45, the document G reflects the light emitted from the light emitting unit through the opening. When the reflected light passes through the opening and is received by the light receiving portion, the discharged original detection sensor 127 outputs an ON signal. On the other hand, when no document is placed on the ejection tray 45, the light emitted from the light-emitting portion through the opening is not reflected by the document, so that it is not received by the light-receiving portion, and the ejected document detection sensor 127 outputs an OFF signal. to output

Next, the elevating mechanism 125 for the paper feed tray 43 will be described with reference to FIGS. 4 to 6. FIG. 4 is a front view showing the lifting mechanism 125, FIG. 5 is a perspective view mainly showing the lifting arm 133 of the lifting mechanism 125, and FIG. 6 is a perspective view mainly showing the lower limit position detection sensor 177 of the lifting mechanism 125.

The elevating mechanism 125 includes a rail 131 along the vertical direction, an elevating arm 133 that supports the paper feed tray 43 and engages with the rail 131 , and a driving unit 135 that elevates the elevating arm 133 along the rail 131 . I have. The lifting mechanism 125 is provided on the front wall 53 and the rear wall 55 of the body portion 41 below the feeding portion 81 . Specifically, the front wall 53 has a front plate and a front cover that covers the front surface of the front plate, and the rear wall 55 has a rear plate and a rear cover that covers the rear surface of the rear plate. The lifting mechanism 125 is provided on the front surface of the front side plate and the rear surface of the rear side plate. Hereinafter, the front side plate will be referred to as the front wall 53 and the rear side plate will be referred to as the rear wall 55 for ease of explanation. 3 and 4 show the lifting mechanism 125 provided on the front wall 53, and FIG. 5 shows the lifting mechanism 125 provided on the rear wall 55. FIG.

The rail 131 is formed along the vertical direction on the front wall 53 (and the rear wall 55) and has a pair of parallel rail pieces 131a along the vertical direction. The lifting arm 133 includes an engaging portion 141 that engages with the rail 131, a supporting portion 143 that is provided upstream of the engaging portion 141 and supports the downstream end of the paper feed tray 43, and an engaging portion. and a connecting portion 145 that is provided on the downstream side of 141 and connects to the driving portion 135 . The engaging portion 141 includes upper and lower bearings 151 (see FIGS. 5 and 6). The upper and lower bearings 151 are supported between a pair of rail pieces 131a of the rail 131. As shown in FIG. A projecting piece 155 projecting outward is formed on the connecting portion 145 .

The drive unit 135 is arranged downstream of the rail 131 . The drive unit 135 includes a driving sprocket 161 that rotates around a drive shaft parallel to the width direction, a plurality of sprockets 163 (163A, 163B) that rotate around a rotation shaft parallel to the width direction, and a drive sprocket. 161 and a timing belt 167 wound around a plurality of sprockets 163 .

The drive sprocket 161 is arranged downstream of the upper end of the rail 131, and the drive shaft is rotatably supported by the front wall 53 (and the rear wall 55). A lift motor 173 (see FIG. 4) is connected to one end of the drive shaft. The lift motor 173 is, for example, a DC motor. The lift motor 173 is supported by a bracket 171 (see FIG. 6) fixed to the front wall 53 (and rear wall 55).

One sprocket 163A out of the plurality of sprockets 163 is arranged below the driving sprocket 161, and its rotating shaft is rotatably supported by the front wall 53 (and the rear wall 55). The other sprocket 163B is arranged downstream of the drive sprocket 163, and its rotating shaft is rotatably supported by the front wall 53 (and the rear wall 55). A timing belt 167 is wound around these sprockets 161 and 163 .

The driving shaft is driven by the lifting motor 173 to rotate the driving sprocket 161, causing the timing belt 167 to run in both directions. At this time, the linear portion 167x of the timing belt 167 between the drive sprocket 161 and the sprocket 163A arranged below it runs along the vertical direction parallel to the rails 131. As shown in FIG.

The connecting portion 145 of the lifting arm 133 is connected to the linear portion 167x of the timing belt 167. As a result, when the timing belt 167 runs, the lift arm 133 moves up and down along the rail 131 . Specifically, the upper and lower bearings 151 of the engaging portion 141 of the lifting arm 133 slide along the inner surfaces of the pair of rail pieces 131 a of the rail 131 . As the lift arm 133 moves up and down in this way, the paper feed tray 43 moves up and down.

The paper feed tray 43 is moved up and down between the upper limit position and the lower limit position by the lifting mechanism 125 . The lower limit position is, for example, a position where a large amount of documents G (eg, 500 sheets) can be placed. The lifting mechanism 125 is provided with a lower limit position detection sensor 177 (see FIG. 6) that detects that the paper feed tray 43 has been lowered to the lower limit position. Lower limit position detection sensor 177 is supported by bracket 171 . The lower limit position detection sensor 177 is, for example, a transmissive optical sensor having a light emitting portion and a light receiving portion. When an optical path is formed between the light emitting portion and the light receiving portion, the lower limit position detection sensor 177 outputs an ON signal, and outputs an OFF signal when the optical path is blocked. When the paper feed tray 43 is lowered to the lower limit position, the projecting piece 155 of the connecting portion 145 of the lifting arm 133 enters between the light emitting portion and the light receiving portion to block the optical path, and the lower limit position detection sensor 177 outputs an ON signal.

On the other hand, when the paper feed tray 43 is lifted, the top document among the documents G stacked on the paper feed tray 43 comes into contact with the delivery roller 103 (see FIGS. 2 and 3) of the delivery section 49 . When the paper feed tray 43 is further raised, the delivery roller 103 is pushed up by the document G, and the holder 101 rotates upward around the drive shaft 109a. The paper feed tray 43 rises until the holder 101 swings to the upper limit position, that is, the feed roller 103 rises to a predetermined paper feed height. Thus, the paper feed tray 43 rises to the upper limit position where the projecting piece 101a of the holder 101 blocks the optical path of the upper limit position detection sensor 115 and the upper limit position detection sensor 115 transmits an ON signal.

At this upper limit position, the feeding roller 103 is raised to the predetermined sheet feeding height as described above, so by rotating the driving shaft 109a of the driving roller 109 of the feeding section 49, the sheet is placed on the sheet feeding tray 43. The fed document G is appropriately delivered by the delivery roller 103 , and the delivered document G is transported to the transport path 69 by the transport belt 105 and the auxiliary roller 107 .

The lifting mechanism 125 also includes an intermediate position detection sensor 179 (see FIG. 7, shown in FIGS. 4 to 6) for detecting that the paper feed tray 43 has moved up and down to an intermediate position between the lower limit position and the upper limit position. omitted) are provided. The intermediate position is a position where, for example, a smaller number of documents G (for example, 320 sheets) than the large capacity can be placed on the paper feed tray 43 . Intermediate position detection sensor 179 is supported by bracket 171 (see FIG. 6). The intermediate position detection sensor 179 is, for example, a transmissive optical sensor having a light emitting portion and a light receiving portion. The intermediate position detection sensor 179 outputs an OFF signal when an optical path is formed between the light emitting section and the light receiving section, and outputs an ON signal when the optical path is blocked. When the paper feed tray 43 moves up and down and the projecting piece 155 (see FIGS. 4 to 6) enters between the light emitting portion and the light receiving portion to block the optical path, the intermediate position detection sensor 179 outputs an ON signal.

Next, the control section 201 of the document conveying device 7 will be described with reference to the block diagram of FIG. The control unit 201 includes a fed document detection sensor 123 (see FIGS. 2 and 3), a discharged document detection sensor 127 (see FIG. 3), an upper limit position detection sensor 115 (see FIG. 3), and a lower limit position detection sensor 177 (see FIG. 6), and the intermediate position detection sensor 179 transmits a detection result (on signal or off signal). Further, the control unit 201 controls driving of the drive motor 113 of the delivery unit 81 and the lift motor 173 of the lift mechanism 125 .

When the controller 201 receives an ON signal from the fed document detection sensor 123 , it determines that the document G is placed on the feed tray 43 . Further, when receiving an ON signal from the ejected document detection sensor 127 , the control unit 201 determines that the document G is stacked on the ejection tray 45 .

Further, when receiving an ON signal from the upper limit position detection sensor 115, the control unit 201 determines that the holder 91 has rotated to the upper limit position, that is, that the paper feed tray 43 has risen to the upper limit position. Further, when receiving an ON signal from the lower limit position detection sensor 177, the control unit 201 determines that the paper feed tray 43 has been lowered to the lower limit position. Further, when receiving an ON signal from the intermediate position detection sensor 179, the control unit 201 determines that the paper feed tray 43 has moved up and down to the intermediate position.

A first example of document transport processing in the document transport device 7 having the above configuration will be described with reference to the flowchart of FIG. In the first embodiment, processing during standby in which the document conveying operation is not executed will be described. During standby, the paper feed tray 43 is lowered to the lower limit position in order to cope with the case where a large amount of documents G such as about 500 sheets are placed on the paper feed tray 43 .

In step S<b>1 , the control unit 201 determines whether or not an ON signal has been received from the fed document detection sensor 123 , that is, whether or not the document G has been placed on the feed tray 43 . If it is determined in step S1 that an ON signal has been received from the fed document detecting sensor 123, ie, that the document G has been placed on the feeding tray 43, the process proceeds to step S2. If it is not determined that the ON signal has been received from the fed document detecting sensor 123, the process of step S1 is repeated.

In step S<b>2 , the control unit 201 drives the elevation motor 173 to raise the paper feed tray 43 . As a result, the document G placed on the paper feed tray 43 is lifted. When the paper feed tray 43 rises in this way, the feed roller 103 is pushed up by the uppermost document G, and the holder 91 rotates upward (see FIG. 3).

After that, in step S3, the control unit 201 determines whether an ON signal has been received from the upper limit position detection sensor 115, that is, whether the paper feed tray 43 has risen to the upper limit position. Until the ON signal is received from the upper limit position detection sensor 115 in step S3, the control unit 201 repeats the process of step S3.

When it is determined in step S3 that an ON signal has been received from the upper limit position detection sensor 115, ie, that the paper feed tray 43 has risen to the upper limit position, the process proceeds to step S4. In step S<b>4 , the control unit 201 stops driving the lifting motor 173 . As a result, the paper feed tray 43 stops while the uppermost document G is in contact with the delivery roller 103 . After that, the process proceeds to step S5.

In step S<b>5 , the control unit 201 determines whether an OFF signal has been received from the fed document detection sensor 123 , that is, whether or not the document G has been removed from the feed tray 43 . If it is determined in step S5 that the document G has been removed from the paper feed tray 43, the process proceeds to step S6. If it is determined in step S5 that the document G has not been taken out from the paper feed tray 43, the process ends.

In step S6, the control unit 201 drives the elevation motor 173 to lower the paper feed tray 43. After that, the process proceeds to step S7.

In step S7, the control unit 201 determines whether or not an ON signal has been received from the discharged document detection sensor 127, that is, whether or not the document G is placed on the discharge tray 45. When it is determined in step S7 that the document G is placed on the discharge tray 45, the process proceeds to step S8.

In step S8, the control unit 201 determines whether an ON signal has been received from the intermediate position detection sensor 179, that is, whether the paper feed tray 43 has been lowered to the intermediate position. If it is determined in step S8 that the paper feed tray 43 has descended to the intermediate position, the process proceeds to step S9. The control unit 201 repeats the process of step S8 until it is determined in step S8 that the paper feed tray 43 has been lowered to the intermediate position.

On the other hand, if it is determined in step S7 that the document G is not placed on the discharge tray 45, the process proceeds to step S10.

In step S10, the control unit 201 determines whether an ON signal has been received from the lower limit position detection sensor 177, that is, whether the paper feed tray 43 has been lowered to the lower limit. When it is determined in step S10 that the paper feed tray 43 has been lowered to the lower limit, the process proceeds to step S9. The process of step S10 is repeated until it is determined in step S10 that the paper feed tray 43 has been lowered to the lower limit.

In step S9, the control unit 201 drives the lifting motor 173 to stop the paper feed tray 43, and ends the process. Thus, the paper feed tray 43 stops at the intermediate position when the document G is placed on the discharge tray 45 and stops at the lower limit position when the document G is not placed on the discharge tray 45 .

After the above processing is completed, the operation of conveying the document G can be started. For example, after placing a document on the paper feed tray 43, the user presses a start key provided on an operation panel (not shown) of the image forming apparatus 3 (see FIG. 1) to start feeding the document. do.

When the start key is pressed, the control unit 201 drives the elevation motor 173 to raise the paper feed tray 43 to the upper limit position. After that, the control unit 201 drives the drive motor 113 to rotate the drive shaft 99a (see FIG. 3), feeds the document G by the feed roller 103, and conveys the fed document G by the transport belt 105 and the auxiliary roller 107. transport to path 69; The document transported to the transport path 69 is transported to the reading position P by the first to fourth transport roller pairs 81 , 83 , 85 and 87 . Then, when passing through the reading position P, the image of the document G is read by the document reading device 5 . After that, the document G is transported along the discharge path 73 by the fifth transport roller pair 95 , discharged from the discharge port 71 by the discharge roller pair 97 , and stacked on the discharge tray 45 .

As described above, according to the present invention, when the document G is removed from the paper feed tray 43 during standby, the paper feed tray 43 is lowered. When the document G is taken out from the paper feed tray 43 during standby, the paper feed tray 43 is raised until the placed document G comes into contact with the feeding roller 103 . If the document G is taken out in this state, the paper feed tray 43 remains raised, and the amount of the document G that can be placed on the paper feed tray 43 is reduced. As in the present invention, when the document G is taken out from the paper feed tray 43 during standby, the paper feed tray 43 is lowered to increase the amount of the document G to be placed next on the paper feed tray 43. be able to.

Furthermore, the position at which the paper feed tray 43 is stopped can be changed depending on whether or not the document G is placed on the discharge tray 45 . Specifically, when no documents G are placed on the discharge tray 45, the amount of documents G that can be placed on the paper feed tray 43 can be maximized by lowering the paper feed tray 43 to the lower limit position. On the other hand, when the document G is placed on the discharge tray 45, the paper feed tray 43 is lowered to the intermediate position. As a result, the originals G stacked on the discharge tray 45 can be prevented from interfering with the paper feed tray 43, and the space for removing the originals G from the discharge tray 45 can be secured. can be as large as possible.

Next, another example of the document conveying device 7 will be described with reference to FIGS. 9A and 9B. 9A and 9B are sectional views showing the document conveying device 7. FIG.

In the document conveying device 7 of this example, the rocking mechanism 301 for rocking the discharge path 73 so that the discharge port 71 moves vertically and the discharge port 71 and the paper feed tray 43 are brought close to each other by a predetermined distance. and an approach detection unit 303 that detects the

As described above, the discharge path 73 is formed between upper and lower plate-

like guide members

75 and 77 facing each other with a gap through which the document G can pass. The fifth conveying roller pair 95 is arranged on the downstream side of the reading device P, and has a driving roller rotatably supported by the upper guide member 75 and a driven roller rotatably supported by the lower guide member 77 . The discharge roller pair 97 is arranged upstream of the discharge port 71 , the driving roller is rotatably supported by the upper guide member 75 and the driven roller is rotatably supported by the lower guide member 77 .

The rocking mechanism 301 includes an eccentric cam 311 and a rocking motor 313 that rotates the eccentric cam 311 . The discharge path 73 (upper and lower guide members 75 and 77) is supported so as to be vertically rotatable around the drive shaft of the drive rollers of the fifth discharge roller pair 95. As shown in FIG. The eccentric cam 311 is rotatably supported below the discharge passage 73 in contact with the lower guide member 77 . When the swing motor 313 is driven to rotate the eccentric cam 311, the discharge path 73 rotates vertically about the drive shaft, and the discharge port 71 moves vertically. The outlet 71 is movable between a lower limit position (see FIG. 9A) and an upper limit position (see FIG. 9B).

By moving the discharge port 71 upward, the distance between the discharge port 71 and the discharge tray 45 is lengthened, and the amount of documents G stacked on the discharge tray 45 can be increased. However, if the discharge port 71 is moved upward, there is a risk of interference between the lowered paper feed tray 43 and the discharge port 71 (upper and lower guide members 75 and 77).

The proximity detection unit 303 detects the relative position between the discharge port 71 and the paper feed tray 43 . and a projecting piece 317 provided on the . The detection sensor 315 is, for example, a transmissive optical sensor having a light-emitting portion and a light-receiving portion. The detection sensor 315 outputs an ON signal when an optical path is formed between the light emitting part and the light receiving part, and outputs an OFF signal when the optical path is blocked. The proximity detection sensor 315 may be provided on the lifting arm 133 of the lifting mechanism 125 (see FIG. 4).

The proximity detection sensor 315 and the projecting piece 317 are arranged so that the projecting piece 317 blocks the optical path of the optical sensor 315 when the paper feed tray 43 and the paper discharge port 71 come close to each other at a predetermined distance.

The swing motor 313 is controlled and driven by the control unit 201 . Also, the detection result (ON signal or OFF signal) of the approach detection sensor 315 is transmitted to the control unit 201 . When the ON signal is received from the proximity detection sensor 315, the control unit 201 determines that the paper feed tray 43 and the discharge port 71 have come close to each other within a predetermined distance.

For example, when the approach detection sensor 315 transmits an ON signal to the control unit 201 while the paper feed tray 43 is being lowered in S6 of the flowchart shown in FIG. has approached a predetermined distance, and the driving of the lifting motor 173 is stopped.

In this example, the discharge port 71 can be moved upward by the swing mechanism 301 in order to increase the stacking amount of the documents G on the discharge tray 43 (see FIG. 9B). However, when the discharge port 71 is moved upward in this way, the paper feed tray 43 and the discharge port 71 may interfere with each other when the paper feed tray 43 descends after the document G is taken out from the paper feed tray 43 . be. According to this example, when the paper feed tray 43 and the discharge port 71 approach each other, the paper feed tray 43 stops before reaching a predetermined position (lower limit or intermediate position). In addition, it is possible to increase the stacking amount of the documents G on the discharge tray 43 while increasing the amount of the documents G placed on the paper feed tray 43 .

Next, a second embodiment of the document conveying process of the document conveying device 7 will be described with reference to the flowchart of FIG. In the second embodiment, the processing after the document conveying operation is finished will be described.

In step S21, the control unit 201 determines whether or not an OFF signal has been received from the fed document detecting sensor 123 after the document feeding operation is started, that is, whether or not all the documents G placed on the feeding tray 43 have been fed. (whether or not the document conveying operation has ended). In step S21, when an off signal is received from the fed document detection sensor 123, the process proceeds to step S22. The control unit 201 repeats the process of step S21 until the OFF signal is received from the fed document detecting sensor 123. FIG.

As described above, the paper feed tray 43 is raised by the elevating mechanism 125 so that the top document among the placed documents G contacts the delivery roller 53 . When all the documents G placed on the paper feed tray 43 have been conveyed, that is, when the OFF signal is received from the paper feed detection sensor 123, the paper feed tray 43 is raised to the upper limit position.

In step S22, the control unit 201 drives the elevation motor 173 to lower the paper feed tray 43. After that, the process proceeds to step S23.

In step S23, the control unit 201 determines whether or not an ON signal has been received from the discharged document detection sensor 127, that is, whether or not the document G is placed on the discharge tray 45. When it is determined in step S23 that the document G is placed on the discharge tray 45, the process proceeds to step S24.

In step S24, the control unit 201 determines whether an ON signal has been received from the intermediate position detection sensor 179, that is, whether the paper feed tray 43 has been lowered to the intermediate position. When it is determined in step S24 that the paper feed tray 43 has descended to the intermediate position, the process proceeds to step S25. The control unit 201 repeats the process of step S24 until it is determined that the paper feed tray 43 has been lowered to the intermediate position.

On the other hand, if it is determined in step S23 that no document is placed on the discharge tray 45, the process proceeds to step S26.

In step S26, the control unit 201 determines whether an ON signal has been received from the lower limit position detection sensor 177, that is, whether the paper feed tray 43 has been lowered to the lower limit position. When it is determined in step S26 that the paper feed tray 43 has been lowered to the lower limit position, the process proceeds to step S25. The control unit 201 repeats the process of step S26 until it is determined that the paper feed tray 43 has been lowered to the lower limit.

In step S25, the control unit 201 stops the lifting motor 173 to stop the paper feed tray 43, and ends the process. Thus, the paper feed tray 43 stops at the intermediate position when the document G is stacked on the discharge tray 45, and stops at the lower limit position when no document is placed on the discharge tray 45. FIG.

The processing of steps S22 to S26 is the same as the processing of steps S6 to S10 of the document conveying operation in the first embodiment.

After the document transport operation is completed, the paper feed tray 43 is normally raised to the upper limit position as described above, so the amount of documents G that can be placed on the paper feed tray 43 is limited. According to the second embodiment, by lowering the paper feed tray 43 after completing the document transport operation, the amount of the next document G to be placed on the paper feed tray 43 can be increased.

Further, as in the first embodiment, when no document is placed on the discharge tray 45, the paper feed tray 43 is lowered to the lower limit position, thereby removing the document G that can be placed on the paper feed tray 43. can maximize quantity. On the other hand, when the document G is placed on the discharge tray 45, the paper feed tray 43 is lowered to the intermediate position. As a result, the originals G stacked on the discharge tray 45 can be prevented from interfering with the paper feed tray 43, and the space for removing the originals G from the discharge tray 45 can be secured. can be as large as possible.

Also, in the second embodiment, similarly to the other examples of the first embodiment, the swinging mechanism 301 of the discharge port 71 and the approach detection section 303 may be provided. In this case, as in the first embodiment, interference between the paper feed tray 43 and the discharge port 71 is prevented to increase the amount of the originals G placed on the paper feed tray 43 and to the discharge tray 45. The stacking amount of the document G can be increased.

Claims

A paper feed tray on which documents are stacked and which can be raised and lowered;
a fed document detection sensor that detects the presence or absence of the document on the paper feed tray;
a discharge tray provided below the paper feed tray;
an ejected document detection sensor that detects the presence or absence of the document on the ejection tray;
a transport path along which the document is transported from the paper feed tray toward a reading position;
a discharge path through which the document is conveyed from the reading position toward a discharge port;
a feed roller that rotates in contact with the originals stacked on the paper feed tray to feed the originals onto the transport path;
The paper feed tray is moved between an upper limit position where the stacked documents are pressed against the delivery roller and the delivery roller is raised to a predetermined paper feed height, and a lower limit position spaced downward from the delivery roller. A lifting mechanism for lifting and lowering,
When it is determined that the document has been taken out from the paper feed tray based on the detection result of the fed document detection sensor during standby when the document transport operation is not executed, the lifting mechanism moves the discharged document. 1. A document feeder, wherein the paper feed tray is lowered to a predetermined position according to a detection result of a detection sensor.
a lower limit position detection sensor that detects that the paper feed tray has descended to the lower limit position;
an intermediate position detection sensor that detects that the paper feed tray has moved up and down to an intermediate position between the lower limit position and the upper limit position;
When it is determined that the document has been taken out from the paper feed tray based on the detection result of the fed document detection sensor,
When it is determined that the document is not stacked on the discharge tray based on the detection result of the discharged document detection sensor, the lifting mechanism continues to rotate the paper feed until the lower limit position detection sensor detects the paper feed tray. lower the tray
When it is determined that the document is stacked on the discharge tray based on the detection result of the discharged document detection sensor, the elevating mechanism moves the paper feed until the intermediate position detection sensor detects the paper feed tray. 2. The document conveying apparatus according to claim 1, wherein the tray is lowered.
a swing mechanism for swinging the discharge passage so that the discharge port moves vertically;
a proximity detection unit that detects that the discharge port and the paper feed tray are close to each other at a predetermined distance;
When the approach detection unit detects that the discharge port and the paper feed tray are approaching the predetermined distance during the descent of the paper feed tray, the lifting mechanism stops the descent of the paper feed tray. 2. The document conveying device according to claim 1.
A paper feed tray on which documents are stacked and which can be raised and lowered;
a fed document detection sensor that detects the presence or absence of the document on the paper feed tray;
a discharge tray provided below the paper feed tray;
an ejected document detection sensor that detects the presence or absence of the document on the ejection tray;
a transport path along which the document is transported from the paper feed tray toward a reading position;
an ejection path through which the document is transported from the reading position toward an ejection port;
a feed roller that rotates in contact with the originals stacked on the paper feed tray to feed the originals onto the transport path;
The paper feed tray is moved between an upper limit position where the stacked documents are pressed against the delivery roller and the delivery roller is raised to a predetermined paper feed height, and a lower limit position spaced downward from the delivery roller. A lifting mechanism for lifting and lowering,
When it is determined that the operation of conveying the document has been completed based on the detection result of the fed document detection sensor, the elevating mechanism moves the paper feed tray to a predetermined position according to the detection result of the discharged document detection sensor. A document conveying device characterized in that it is lowered to a position of .
a lower limit position detection sensor that detects that the paper feed tray has descended to the lower limit position;
an intermediate position detection sensor that detects that the paper feed tray has moved up and down to an intermediate position between the lower limit position and the upper limit position;
When it is determined that the document has been taken out from the paper feed tray based on the detection result of the fed document detection sensor,
When it is determined that the document is not stacked on the discharge tray based on the detection result of the discharged document detection sensor, the lifting mechanism continues to rotate the paper feed until the lower limit position detection sensor detects the paper feed tray. lower the tray
When it is determined that the document is stacked on the discharge tray based on the detection result of the discharged document detection sensor, the elevating mechanism moves the paper feed until the intermediate position detection sensor detects the paper feed tray. 5. The document conveying device according to claim 4, wherein the tray is lowered.
a swing mechanism for swinging the discharge passage so that the discharge port moves vertically;
a proximity detection unit that detects that the discharge port and the paper feed tray are close to each other at a predetermined distance;
When the approach detection unit detects that the discharge port and the paper feed tray are approaching the predetermined distance during the descent of the paper feed tray, the lifting mechanism stops the descent of the paper feed tray. 5. The document conveying device according to claim 4.