JP2008260612A - Manuscript separating and feeding device and image reading device equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manuscript separating and feeding device capable of reducing the cost of replacement parts, simplifying the structure of the device, and smoothly separating and supplying a manuscript, and to provide an image reading device using the same. <P>SOLUTION: A retard roller unit 13A comprises a retard roller 13, a retard roller shaft 13a for concentrically holding the retard roller 13, and a driven transmission gear 13c concentrically fixed to the retard roller shaft 13a. A drive transmission means 14 for transmitting drive to the retard roller 13 is installed in a device main body 1A. The drive transmission means 14 is equipped with a rotary driving shaft 15, a drive transmission gear 18, a pair of bracket members 20 for supporting the retard roller shaft 13a at both ends in the axial direction, and a pair of elastic force applying means 25, 26 for applying elastic force to bring the retard roller 13 in elastic contact with a separate roller 12. The retard roller unit 13A is detachably supported by the bracket members 20 via the retard roller shaft 13a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a document separation and supply apparatus for supplying a document to an image reading apparatus installed in an image reading machine, a copying machine, a facsimile machine, and the like, and an image reading apparatus including the document separation and supply apparatus.

  The image reading apparatus as described above includes a document separation and supply device for separating and supplying a large number of documents placed on a document supply tray one by one. The original supplied separately from the original supply / separation apparatus is conveyed along the original conveyance path, and the image information is sequentially read by the original reading scanning means arranged in the middle of the original conveyance path, and the downstream side of the original conveyance path. The document is discharged to a document discharge tray provided at the end. As a document separation and supply apparatus provided in such an image reading apparatus, a so-called retard roller type or separation pad type is often used. As an example of the former retard roller type document separation and supply apparatus, Patent Document 1 discloses. And what was indicated by patent document 2 is mentioned. These retard roller type document separating and supplying apparatuses are composed of a separate roller and a retard roller that is elastically in contact with the separate roller. The retard roller is rotationally driven to resist the document supply action by the separate roller, and both rollers are in contact with each other. A document to be fed overlapping a portion (nip portion) is pushed back by a push-back action by the rotation of the retard roller, and only one sheet contacting the separation roller is separated and supplied.

In the case of the retard roller type document separation and supply apparatus as described above, the separation and supply performance of the document may be deteriorated due to wear of the roller surface over time or the like. Therefore, it may be necessary to replace parts. Therefore, these rollers are configured to be attached to the casing (apparatus main body) of the document separation / supply apparatus via a simple attachment / detachment mechanism. By the way, in the case of the retard roller, the structure of the attaching / detaching mechanism becomes a problem because the drive transmission system and the mechanism of the elasticity applying means for applying elasticity to the separate roller are involved. In Patent Document 1, one of a pair of support members that support both ends of the roller body in the axial direction is movable in the axial direction so that the roller body can be attached and detached. Further, in the case of the document separation and supply apparatus disclosed in Patent Document 2, a bracket (arm) for determining the distance between the driven transmission gear fixed to the retard roller shaft and the drive transmission gear meshing with the driven transmission gear is attached to the retard roller shaft. Since the bracket can be detachably attached to the shaft of the drive transmission gear attached to the apparatus main body, the retard roller can be attached and detached together with the bracket.
JP 09-188434 A JP 2005-57341 A

  Since the retard roller attaching / detaching mechanism disclosed in the above-mentioned Patent Document 1 is designed so that only the retard roller main body is attachable / detachable, the replacement part is simple, and the cost of the replacement part can be reduced. In this case, the retard roller main body supported by the pair of support members is connected to the transmission shaft for rotational driving along the axial direction, but at the same time, separated by the spring member (at right angles to the transmission shaft). Direction). Therefore, two universal joints are provided at both ends (drive source side and retard roller side) of the transmission shaft so as to absorb the elasticity in the direction perpendicular to the transmission shaft and to facilitate drive transmission through the transmission shaft. Thus, a complicated drive transmission mechanism must be provided on the apparatus main body side. In addition, since one spring member for applying elasticity to the retard roller is provided in the central portion in the axial direction of the retard roller, the elasticity provided by this spring member is applied to the drive transmission side with a connected load and the load. An imbalance occurs between the non-drive transmission side and the non-drive transmission side. For this reason, the contact pressure between the retard roller and the separation roller is not uniform in the axial direction, and this causes the document to be fed out obliquely from the nip portion, resulting in a document transport jam in the subsequent transport process and image reading process. Or an image reading error may occur.

  On the other hand, the document separation and supply apparatus disclosed in Patent Document 2 is configured such that drive transmission is performed by meshing between a drive transmission gear attached to the apparatus main body side and a driven transmission gear fixed to the retard roller shaft. Therefore, a complicated drive transmission mechanism via two universal joints as in Patent Document 1 is unnecessary. However, since the retard roller and the bracket are combined to form one part, the cost as a replacement part increases. In addition, since one spring member for applying elasticity to the retard roller is provided at the central portion in the axial direction of the retard roller, the elasticity provided by this spring member is the same as that described above. In this case, an imbalance may occur between the non-load transmitting side and the non-drive transmission side, and the document may be fed out obliquely from the nip portion, causing the same problem as described above in the subsequent document conveyance process.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is intended to reduce the cost of replacement parts and simplify the apparatus configuration, and to use a document separating and supplying apparatus capable of smoothly separating and supplying documents. An object of the present invention is to provide an image reading apparatus.

  According to a first aspect of the present invention, there is provided a document separation and supply apparatus that separates and supplies a document placed on a document supply tray one by one by the action of a separation roller and a retard roller that elastically contacts the separation roller. A retard roller unit is constituted by the retard roller, a retard roller shaft that concentrically holds the retard roller, and a driven transmission gear that is concentrically fixed to the retard roller shaft. Drive transmission means for transmitting the drive to the retard roller is installed, and the drive transmission means is engaged with the rotational drive shaft and the driven transmission gear to transmit the rotational drive force from the rotational drive shaft. A drive transmission gear, and a bearing portion that is swingably supported about the axis of the drive transmission gear and supports the retard roller shaft at both axial ends. A pair of bracket members and a pair of elastic force applying means provided on both bracket member sides for elastically contacting the retard roller so as to elastically contact the separate roller, and the retard roller unit includes the bracket member On the other hand, the bearing portion is detachably supported via a retard roller shaft.

  In the document separating and supplying apparatus according to the present invention, the pair of bracket members are fixed with a pair of concentric support shafts facing each other and the drive transmission gear is rotatable about the shaft center on one support shaft. The rotary drive shaft supports a pair of oscillating arms so as to be able to oscillate about its axis, and concentrically fixes a drive side gear meshing with the drive transmission gear. A drive transmission system from the rotational drive shaft to the driven transmission gear via the drive transmission gear and the support mechanism thereof by connecting to the pair of support shafts at the oscillating end portions so as to be relatively rotatable about the axis. You may make it comprise.

  Further, a base frame for supporting the bracket member is installed in the apparatus main body, and the base frame includes a guide support portion that supports the bearing portion of the bracket member so as to be linearly movable, and a holding portion of the elasticity applying means. It is good also as having. In this case, it is desirable that the linear movement direction be along a line connecting the shaft center of the bearing portion supported by the guide support portion and the shaft center of the separate roller. Further, the bracket member is composed of a bearing member and a bracket that is fitted to the outer periphery of the bearing member so as to be rotatable about its axis, and the bracket member and the fitting portion of the bracket to the bearing member A bearing part is comprised and this bearing member shall be supported by the said guide support part so that linear movement is possible.

  An image reading apparatus according to a second aspect of the present invention is disposed in any of the above document separation and supply apparatus, a document conveyance path for conveying a document separated and supplied from the document separation and supply apparatus, and in the middle of the document conveyance path. And a document discharge tray provided at the downstream end of the document transport path.

  According to the document separating and supplying apparatus according to the first invention, the retard roller, the retard roller shaft that concentrically holds the retard roller, and the driven transmission gear that is concentrically fixed to the retard roller shaft. Since the retard roller unit is detachably supported by the bearing portion of the bracket member provided on the apparatus main body side with respect to the apparatus main body, the component cost of the retard roller unit as a replacement part can be reduced. This can reduce the burden on the user. In addition, since the driven transmission gear fixed to the retard roller shaft is meshed with the drive transmission gear that transmits the rotational driving force of the rotational drive shaft on the main unit side, the rotational drive transmission mechanism to the retard roller is configured. The apparatus configuration can be simplified. In addition, a pair of elastic force applying means for applying elastic force so that the retard roller supported by the pair of bracket members elastically contact the separating roller is provided on both bracket sides. The connecting load on the drive transmission side due to meshing with the gear is alleviated by the elastic force applied to both ends of the retard roller shaft, and the contact pressure between the retard roller and the separate roller does not become unbalanced in the axial direction, Smooth separation and supply of originals.

  As described above, the rolling relationship of the pair of swinging arms and the bracket member, which are swingably supported by the rotational drive shaft, via the pair of support shafts, the drive-side gear fixed to the rotational drive shaft, and the drive transmission By configuring the drive transmission system from the rotational drive shaft to the driven transmission gear via the drive transmission gear and the support mechanism thereof by the meshing relationship between the gear and the drive transmission gear and the driven transmission gear, In a series of drive transmission systems, the distance between the shafts of the gears was kept constant by correlating the swing of the swing arm around the rotational drive shaft and the relative rotation of the bracket member around the support shaft with respect to the swing arm. In this state, the drive is transmitted, and the elastic contact of the retard roller to the separate roller by the elastic force applying means is easily maintained. Therefore, it is not necessary to interpose connection means such as a universal joint, and the apparatus configuration is further simplified.

  Further, a base frame for supporting the bracket member is installed in the apparatus main body, and the base frame includes a guide support portion that supports the bearing portion of the bracket member so as to be linearly movable, and a holding portion of the elasticity applying means. The elastic force is applied to the bearing portion of the bracket member along the linear movement direction by the elastic force applying means, so that the retard roller is always more elastic than the constant direction with respect to the separate roller. Will come in contact with. In this case, if the linear movement direction is along a line connecting the shaft center of the bearing portion supported by the guide support portion and the shaft center of the separate roller, the elastic force by the elastic force applying means is reduced between the retard roller and the separate roller. It passes through the nip portion with the roller toward the axis of the separation roller, and the function of separating and supplying the original document by the cooperative action of the separation roller and the retard roller in this nip portion is exhibited very suitably.

  Further, the bracket member is composed of a bearing member and a bracket that is fitted to the outer periphery of the bearing member so as to be rotatable about its axis, and the bracket member and the fitting portion of the bracket to the bearing member If the bearing part is constituted and the bearing member is supported by the guide support part so as to be linearly movable, the bearing part can swing around the axis of the swing arm and the drive transmission gear attached thereto. In the connecting relationship with the bracket member supported by the bracket member, the linear movement of the bearing support member by the elastic force imparting means is smoothly performed by the rotation of the bracket member around the axis of the bearing member and the retard The distance between the shaft center of the roller shaft and the shaft center of the driven transmission gear is also kept constant, and the drive transmission to the retard roller is smoothly performed without any trouble.

  In the image reading apparatus according to the second aspect of the invention, the original supplied from the original separating / supplying apparatus is smoothly conveyed without being skewed along the original conveying path, and the original jam occurs due to the skew. Instead, the image information is sequentially read by the image reading and scanning means and sequentially discharged onto the document discharge tray. Since the original is introduced into the image reading / scanning means without being inclined, there is no occurrence of a reading defect that causes the read image to be distorted.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a schematic longitudinal sectional view of an image reading apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view showing an embodiment of an original separating and supplying apparatus provided in the image reading apparatus, and FIG. 4 is a cross-sectional view taken along line XX in FIG. 3, FIG. 5 is a cross-sectional view taken along line Y-Y in FIG. 4, and FIG. 6 is ZZ in FIG. FIG. 7 is an exploded perspective view showing a bracket member mounting structure employed in the document separating and supplying apparatus.

  As shown in FIG. 1, an image reading apparatus 1 according to the present embodiment responds to the recent increasing needs for digitization of a large number of documents, and a large-capacity document supply tray 2 for setting a sheet document S is provided. A document discharge tray 3 is provided at the upper part of the apparatus main body 1A. The image reading apparatus 1 also includes a document supply port 1a for supplying the document S on the document supply tray 2 to the inside of the apparatus body 1A, and the document S after being read inside the apparatus body 1A. A document discharge port 1b for discharging to the discharge tray 3 is provided.

  In the apparatus main body 1A of the image reading apparatus 1, an inverted U-shaped curved document conveyance path P that connects the document supply port 1a and the document discharge port 1b is formed. A plurality of document conveyance paths P are formed along the document conveyance path P. A pair of conveying rollers 4 is installed. In addition, two image scanner devices (image reading / scanning means) 5 and 6 are arranged in the middle of the document transport path P so as to correspond to the front and back of the document S, and both sides of the document S transported through the document transport path P. The image information is sequentially read. In this case, only one of the image scanner devices 5 and 6 may be used to constitute a single-sided image reading device. Any one of the image scanner devices may be configured to be used in combination with a flat bed type image scanner.

  The document tray 2 is supported by a rack 7a constituting the lifting mechanism 7, and the rack 7a meshing with the pinion 7b moves up and down by forward and reverse rotation of the pinion 7b constituting the lifting mechanism 7 together with the rack 7a. Goes up and down. The lifting mechanism 7 is configured such that a large number of documents S stacked and set on the document tray 2 are supplied from the uppermost document into the apparatus main body 1A by the document separation and supply device 10 to be described later. Accordingly, the document tray 2 is raised and the uppermost document S is always subjected to the separation and supply action of the document separation and supply device 10. The gear 7c installed in the lower part of the rack 7a is a resistance gear, and for example, torque grease is applied to the gear shaft so that resistance against rotation is generated, and meshes when the rack 7a is lowered. , Relieve that shock. The elevating mechanism 7 that elevates and lowers the document tray 2 is not limited to a rack and pinion mechanism as shown in the figure, and may be an elevating mechanism that uses a belt or a pulley, for example.

  The document tray 2 includes a side guide 2a for aligning the width edges of the document S to prevent skew during supply, and a document detection sensor 2b for detecting the presence or absence of the document S on the document tray 2. The document detection sensor 2b is electrically connected to the control unit 8. The control unit 8 performs operation control of the elevating mechanism 7, operation control of each part of the document separation and supply apparatus 10, which will be described later, operation control of each conveyance roller pair 4... Do. The document discharge tray 3 has a large-capacity top-opening box shape that can accommodate a large number of discharged documents S in an aligned manner. An operation panel 9 for inputting an image reading start signal or the like is provided on the upper part of the apparatus main body 1A of the image reading apparatus 1.

  A document separation / supply device 10 is installed in the vicinity of the document supply port 1a. The document separation / supply device 10 will be described in detail below. As shown in FIG. 2, the document separating and supplying apparatus 10 includes, as basic components, a pickup roller 11, a separate roller 12 on the downstream side thereof, and a retard roller 13 that elastically contacts the lower surface of the separate roller 12. . When the document supply tray 2 is pushed up by the lifting mechanism 7, the front end portion of the uppermost document S of the document S set in a stacked state on the document supply tray 2 is pressed against the lower surface of the pickup roller 11. It is done. When the pickup roller 11 rotates in the direction of arrow a in this state, the uppermost document S is fed out by the rotational frictional action of the pickup roller 11, and its front end is a nip portion where the separate roller 12 and the retard roller 13 are in elastic contact. To be introduced.

  The separate roller 12 and the retard roller 13 are both made of a frictional member such as rubber, and the coefficient of friction between the surface of the separate roller 12 and the original (paper) S μ1 ≧ the surface of the retard roller 13 and the original (paper) S. The material is selected so that the friction coefficient μ2> the friction coefficient μ3 between the originals (paper) S. The separation roller 12 is driven and transmitted so as to rotate in the direction of the arrow b (the same direction as the direction a), and a rotational force acts on the retard roller 13 in the direction of the arrow c which is counter-rotation with respect to the rotation of the separation roller 12. The drive transmission system is configured to do this. A torque limiter 13b (see FIGS. 3 and 4) is interposed between the retard roller 13 and the retard roller shaft 13a, and the retard roller 13 has a predetermined force or more in a direction e opposite to the arrow c direction. When a load is applied, the rotation is stopped or is rotated in the same direction e.

  As described above, the document S fed out by the pickup roller 11 is introduced from its front end portion into the nip portion where the separation roller 12 and the retard roller 13 are in elastic contact, but before this introduction, the separation roller 12 and Since the retard roller 13 is in direct frictional contact, the retard roller 13 rotates in the direction of arrow e due to the relationship between the friction coefficients and the action of the torque trimming device 13b. Even when only one document S is introduced, the retard roller 13 is rotated or stopped in the direction of arrow e due to the relationship between the friction coefficients and the action of the torque trimming device 13b. However, when a plurality of fed originals S are introduced in a state where they overlap each other, the friction coefficient μ3 between the originals S is small, so that the load acting in the direction of the arrow e is small, whereby the retard roller via the torque regulator 13b. Driven by the shaft 13a, the retard roller 13 rotates in the direction of arrow c. Due to the frictional action associated with the rotation of the retard roller 13 in the direction of the arrow c, the lower document S is pushed back, and only the upper document S of the documents S to be introduced in an overlapping state is separated. Separated and supplied toward the conveyance path P. Guide plates 1c and 1d for smoothly feeding, supplying, and transporting the document S are appropriately provided on the document transport path P from the document supply port 1a and the document discharge port 1b. The guide plate 1c is attached to the apparatus main body 1A so as to be openable and closable, and constitutes a part of a maintenance cover body (not shown) that supports the pickup roller 11 and the separation roller 12.

  A retard roller unit 13A includes the retard roller 13, a retard roller shaft 13a that concentrically holds the retard roller 13 via a torque limiter 13b, and a driven transmission gear 13c that is concentrically fixed to the retard roller shaft 13a. Is configured. In this case, the torque limiter 13b is not necessarily provided between the retard roller 13 and the retard roller shaft 13a, and is provided between the driven transmission gear 13c and the retard roller shaft 13a or at an arbitrary position of the drive transmission system described later. It is also possible to provide it.

  Drive transmission means 14 for transmitting drive to the retard roller 13 is installed in the apparatus main body 1A. The drive transmission means 14 is rotatably installed on the apparatus main body 1A and connected to a rotation drive source (not shown), and a drive side gear 16 concentrically fixed to the rotation drive shaft 15. A pair of oscillating arms 17 and 17 supported on the rotary drive shaft 15 so as to oscillate around its axis, a drive transmission gear 18 meshing with the drive side gear 16, and the oscillating arm 17 facing each other. , 17 includes a pair of bracket members 20, 20 having a pair of concentric support shafts 19, 19 connected to each other at their swing end portions so as to be relatively rotatable about the axis. The rotational drive shaft 15 is installed in a state parallel to the retard roller shaft 13a. The drive transmission gear 18 is supported on one of the support shafts 19 and 19 so as to be rotatable about its axis. Further, the pair of swing arms 17, 17 are connected and integrated in parallel with each other by a connecting plate 17 a parallel to the rotation drive shaft 15.

  The bracket member 20 is composed of bearing members 21 and 22 and brackets 23 and 23 that are fitted to the outer circumferences of the bearing members 21 and 22 so as to be rotatable about the axis thereof, and are installed on the apparatus main body 1A. Supported by the frame 24. The base frame 24 includes a rectangular base plate 24a fixed on the apparatus main body 1A with screws 24aa and the like, and vertical frames 24b and 24c formed at both ends of the base plate 24a. The vertical frames 24b and 24c are provided with mounting spaces 24ba and 24ca for compression springs (elasticity imparting means) that also serve for assembling the bearing members 21 and 22, and vertical notches for supporting the bearing members 21 and 22 so as to be linearly movable. Grooves (guide support portions) 24bb and 24cb and cylindrical holding portions 24bc and 24cc for holding compression springs formed on the lower sides of the mounting spaces 24ba and 24ca are provided. The vertical cutout grooves 24bb and 24cb are formed following the mounting spaces 24ba and 24ca.

  The brackets 23 and 23 are connected and integrated in parallel with each other by a connecting plate 23a parallel to the rotational drive shaft 15, and fitting circular holes 23b and 23b with bearing members 21 and 22 are formed at respective front end portions. Has been. The upper portions of the fitting circular holes 23b and 23b are notched to form notch open portions 23ba and 23ba, and the open width d of the open portions 23ba and 23ba is smaller than the diameter D of the circular holes 23b and 23b. ing.

  The bearing members 21 and 22 include shaft holes 21a and 22a for supporting the retard roller shaft 13a, concave grooves 21b and 22b on both sides, columnar holding portions 21c and 22c for holding a compression spring on the lower surface, and shaft holes. It consists of a molded body provided with 21a, 22a and concentric bracket supporting circular projections 21d, 22d. The shaft holes 21a and 22a rotatably support the retard roller shaft 13a, and the diameter thereof is the same as the diameter of the retard roller shaft 13a. The shaft hole 21a of the bearing member 21 on the non-driving side is U-shaped with the upper portion opened to the same width as the diameter thereof, and the non-driving side portion of the retard roller shaft 13a is pivoted from above through the opening 21aa. It is made to be supported by the hole 21a. On the other hand, the shaft hole 22a of the bearing member 21 on the drive side has a circular shape into which the retard roller shaft 13a can be inserted from the axial direction, and the inlet portion has a tapered surface 22aa with a gradually decreasing diameter.

  The groove widths of the concave grooves 21b and 22b in the bearing members 21 and 22 are set to be slightly larger than the plate thickness of the vertical frames 24b and 24c, and the inner side portions of the vertical notch grooves 24bb and 24cb are fitted so that relative movement can be achieved. It is configured as possible. The bracket supporting projections 21d and 22d have shapes having cut portions 21da and 22da obtained by cutting the upper and lower circular shapes in parallel, and the outer diameter D1 thereof is the same as the diameter D of the circular holes 23b and 23b in the brackets 23 and 23. The width d1 between the cut portions 21da and 22da is slightly smaller than the open width d of the upper open portions 23ba and 23ba in the circular holes 23b and 23b.

  A procedure for assembling the bracket member 20 configured as described above to the base frame 24 will be described. First, the bearing members 21 and 22 are disposed in the mounting spaces 24ba and 24ca in the vertical frames 24b and 24c, and while lifting them upward, the inner side portions of the vertical notches 24bb and 24cb are fitted into the concave grooves 21b and 22b, A compression spring (giving elasticity) between the cylindrical holding portions 21c, 22c of the bearing members 21, 22 and the cylindrical holding portions 24bc, 24cc of the vertical frames 24b, 24c in a state of being supported by the vertical cutout grooves 24bb, 24cb. Means) 25 and 26 are held in a compressed state. In this state, the bearing members 21 and 22 are maintained in a state in which the bearing members 21 and 22 are linearly movable by receiving upward restoring elasticity by the compression springs 25 and 26 along the vertical cutout grooves 24bb and 24cb. This linear movement direction is along a line connecting the axis of the retard roller shaft 13 a supported by the shaft holes 21 a and 22 a of the bearing members 21 and 22 and the axis of the separate roller 12.

  Next, the brackets 23 and 23 are arranged so that the open portions 23ba and 23ba are oriented sideways, and the open portions 23ba and 23ba are aligned with the cut portions 21da and 22da of the protrusions 21d and 22d on the bearing members 21 and 22, respectively. The circular holes 23b and 23b are fitted to the outer circumferences of the protrusions 21d and 22d. Thereafter, the brackets 23, 23 are rotated and held by 90 ° around the axis of the circular holes 23b, 23b, so that the brackets 23, 23 are arranged around the axis of the projections 21d, 22d of the bearing members 21, 22b. It is rotatably supported. Further, the bearing portions 20A and 20A of the bracket members 20 and 20 are configured by the bearing members 21 and 22 and the fitting portions of the brackets 23 and 23 with respect to the bearing members 21 and 22. When the bracket member 20 is assembled, swinging arms 17 and 17 that are swingably supported by the rotary drive shaft 15 are attached to the support shafts 19 and 19 at their swing ends so as to be relatively rotatable. At the same time, the drive side gear 16 and the drive transmission gear 18 are maintained in meshing relationship. As a result, a drive transmission system from the rotary drive shaft 15 to the drive transmission gear 18 and a drive transmission means 14 for transmitting the drive to the retard roller 13 are established.

  When the retard roller unit 13A is attached to and supported by the drive transmission means 14 configured as described above, the retard roller shaft 13a is tilted, and the drive-side tip is aligned with the tapered surface 22aa of the bearing member 22. The end of the retard roller shaft 13a is supported by the shaft hole 21a of the bearing member 21 while being inserted into the shaft hole 22a obliquely from above and in a horizontal state. Stop ring 13aa and 13aa adjacent to brackets 23 and 23 are attached to both ends of the retard roller shaft 13a, whereby the retard roller unit 13A is supported in a state where movement along the axial direction is restricted. The In this supported state, the driven transmission gear 13c meshes with the drive transmission gear 18 attached to the bracket 23, and a drive transmission system up to the driven transmission gear 13c is established.

  When the maintenance cover body (not shown) is closed and locked in a state where the retard roller unit 13A is supported at the predetermined position of the drive transmission means 14 as described above, as shown in FIG. 2, the separate roller 12 and the retard roller 12 13 is in a state where it is elastically contacted against the elasticity of the compression springs 25 and 26, thereby constituting the document separating and supplying apparatus 10. Since the compression springs 25 and 26 are configured so that the elastic force directly acts on each of the bearing members 21 and 22, the elastic force individually acts on the retard roller 13 at both ends in the longitudinal direction. Therefore, by appropriately setting the spring constants of the compression springs 25 and 26 and individually providing spring pressure adjusting means, it is easy to balance the elastic contact pressure of the retard roller 13 against the separating roller 12 in the longitudinal direction. The In particular, in the bearing member 21 on the non-driving side and the bearing member 22 on the driving side, the presence or absence of a coupling load in the drive transmission system affects, and therefore, by providing the elastic force of the compression springs 25 and 26 directly thereto, the above retard can be obtained. The balance of the elastic contact pressure in the longitudinal direction of the roller 13 with respect to the separate roller 12 is accurately adjusted.

  Further, since the bearing members 21 and 22 are guided and supported by the vertical cutout grooves 24bb and 24cb as guide support portions, the elasticity of the compression springs 25 and 26 is linearly applied along the vertical cutout grooves 24bb and 24cb. The retard roller 13 is always given elasticity so that its axis is directed to the axis of the separate roller 12. In this case, the bearing members 21, 22 and the brackets 23, 23 can be rotated relative to each other around the shaft center by the fitting relationship between the bearing portions 20 </ b> A, 20 </ b> A, and can swing about the rotary drive shaft 15. Are connected to the brackets 23 and 23 via the support shafts 19 and 19 so as to be relatively rotatable about the axis, so that the driven transmission gear 13c and the drive transmission gear 18 are connected to each other. Linear vertical movement along the vertical notch grooves 24bb and 24cb of the bearing members 21 and 22 in a state where the distance between the shaft centers and the distance between the shaft centers of the drive transmission gear 18 and the drive side gear 16 are always kept constant. Is smooth and does not interfere with drive transmission.

  And since the drive transmission means 14 installed in the apparatus main body 1A side is comprised by the simple assembly | attachment relationship as mentioned above, it is excellent in the workability | operativity of an assembly | attachment. In addition, the retard roller unit 13A can be easily attached to and detached from the drive transmission means 14 as described above, so that there is little troublesome part replacement, and since there are few component parts, the cost of replacement parts can be reduced. , The burden on the user can be reduced.

  In the image reading apparatus 1 as shown in FIG. 1, the document separating and supplying apparatus 10 and each pair of conveying rollers 4... Have a single drive source (motor), and each drive is performed by controlling an electromagnetic clutch. There are many. In this case, when a document fed out and fed by the document separation and supply device 10 is nipped by the pair of conveyance rollers 4 closest to the downstream side, the electromagnetic clutch related to the document separation and supply device 10 is turned off, and the separation roller 12 and the retard roller 13 are turned off. Control is performed to stop the drive. At this time, since the conveying roller pair 4 is driven and continues to convey the document, the separated roller 12 and the retard roller 13 that are stopped are pulled by the document, and the next document is moved between the documents. It will be drawn in by friction of the material, and will be sent without being separated. In order to prevent such a situation from occurring, a one-way clutch (not shown) is interposed in the drive transmission system of the retard roller 13, and the driving force in the reverse direction from the driving source (the original rotational driving force applied to the retard roller) is Although it transmits, it can also be comprised so that rotation of the direction to rotate forward (direction of rotation) may be locked.

  In the case of the document separating and supplying apparatus as described above, when the document is nipped by the pair of conveyance rollers 4 closest to the downstream side, the drive of the pickup roller 11 is controlled to be stopped. Since the trailing edge of the document may pass through the pickup roller 11 before reaching the conveying roller pair 4, the feeding of the next document is started by the action of the pickup roller 11 that continues to rotate. It can be a cause. In order to prevent such a situation from occurring, a means (not shown) for separating the pickup roller 11 from the upper surface of the deposited original may be incorporated when the original is started to be supplied by the separation roller 12.

  In the above embodiment, the read-only image reading apparatus is exemplified, but the present invention can also be applied to a reading apparatus of a facsimile machine or a copying machine, and the configuration of the apparatus main body shown in FIG. 1 is also limited to this. is not. As the image reading and scanning means, a known image scanner device in which a light source, an optical system such as a mirror and a lens, and an imaging means such as a CCD are combined is used.

1 is a schematic longitudinal sectional view of an image reading apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view illustrating an embodiment of a document separation and supply device provided in the image reading device. It is a perspective view of the principal part of the original document separation and supply apparatus. FIG. 4 is a cross-sectional view taken along line XX in FIG. 3. FIG. 6 is a cross-sectional view taken along line YY in FIG. 4. FIG. 5 is a sectional view taken along line ZZ in FIG. 4. It is a disassembled perspective view which shows the attachment structure of the bracket member employ | adopted as the original document separation supply apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image reading apparatus 1A Apparatus main body 2 Original supply tray 3 Original discharge tray 5 Image scanner apparatus (image reading scanning means)
6 Image scanner device (image reading and scanning means)
DESCRIPTION OF SYMBOLS 10 Original separation supply apparatus 12 Separating roller 13 Retard roller 13A Retard roller unit 13a Retard roller shaft 13c Driven transmission gear 14 Drive transmission means 15 Rotation drive shaft 16 Drive side gear 17 Swing arm 18 Drive transmission gear 19 Support shaft 20 Bracket member 20A Bearing part 21, 22 Bearing member 23 Bracket 24 Base frame 24bb, 24cb Guide support part 24bc, 24cc Holding part 25, 26 Compression spring (elasticity applying means)
P Document transport path S Document

Claims (6)

A document separation and supply device that separates and supplies a document placed on a document supply tray one by one by the action of a separation roller and a retard roller that elastically contacts the separation roller,
A retard roller unit is constituted by the retard roller, a retard roller shaft that concentrically holds the retard roller, and a driven transmission gear that is concentrically fixed to the retard roller shaft.
The apparatus main body is provided with drive transmission means for transmitting the drive to the retard roller. The drive transmission means meshes with the rotational drive shaft and the driven transmission gear to generate rotational drive force from the rotational drive shaft. A pair of bracket members having a drive transmission gear for transmission, a pair of bracket members supported swingably around the axis of the drive transmission gear and supporting the retard roller shaft at both axial end portions, and provided on both bracket member sides A pair of elasticity applying means for applying elasticity to elastically contact the retard roller with the separation roller,
The document separation and supply device, wherein the retard roller unit is detachably supported by the bearing portion with respect to the bracket member via a retard roller shaft. The document separation and supply apparatus according to claim 1,
A pair of support shafts that are concentrically opposed to each other are fixed to the pair of bracket members, and the drive transmission gear is supported on one of the support shafts so as to be rotatable around the shaft center. A pair of oscillating arms are supported so as to be able to oscillate about their axial centers, and a drive side gear meshing with the drive transmission gear is concentrically fixed. A document separating and supplying apparatus, wherein the document separating and supplying apparatus is connected to a support shaft of the first and second support shafts so as to be relatively rotatable about an axis thereof. The document separation and supply apparatus according to claim 1 or 2,
A base frame for supporting the bracket member is installed in the apparatus main body, and the base frame includes a guide support portion that supports a bearing portion of the bracket member so as to be linearly movable, and a holding portion of the elasticity applying means. An apparatus for separating and supplying original documents. The document separation and supply device according to claim 3.
The document separating and supplying apparatus, wherein the linear movement direction is along a line connecting the shaft center of the bearing portion supported by the guide support portion and the shaft center of the separate roller. The document separating and supplying apparatus according to claim 3 or 4,
The bracket member includes a bearing member and a bracket that is fitted to the outer periphery of the bearing member so as to be rotatable about its axis, and the bearing portion is configured by the fitting portion of the bearing member and the bracket with respect to the bearing member. The document separation and supply apparatus, wherein the bearing member is supported by the guide support portion so as to be linearly movable. 6. A document separating and supplying apparatus according to claim 1, a document conveying path for conveying a document separated and supplied from the document separating and supplying apparatus, and an image reading / scanning means disposed in the middle of the document conveying path. And an original discharge tray provided at the downstream end of the original transport path.

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