KR101445212B1 - Auto document feeder having improved document-discharging-part and image forming apparatus including the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a document feeder in which an output unit is improved. A document feeding apparatus according to the present invention includes: a paper feeding unit for gripping a document and feeding the document in a predetermined feeding direction to pass through a predetermined target position; A first sheet discharge roller disposed along the first sheet discharge roller axis and a second sheet discharge roller disposed along the second sheet discharge roller axis in parallel to the first sheet discharge roller axis with a manuscript passed through the target position interposed therebetween, And a discharge section having a second discharge roller disposed therein. Thereby, the structure of the discharge portion can be simplified.

Badge, Roller, Feeder, ADF (Auto Document Feeder), Automatic, Document

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document transporting apparatus and an image forming apparatus including the document transporting apparatus and an image forming apparatus including the document transporting apparatus.

1 is a schematic cross-sectional view of a main part of a conventional image forming apparatus,

2 is a schematic cross-sectional view of a document feeder according to the present invention,

Fig. 3 is a schematic perspective view of the main portion of the document feeder of Fig. 2,

FIG. 4 is a schematic view showing a document feeding path of the document feeding apparatus of FIG. 2 in the one-

Fig. 5 is an enlarged sectional view of the main part of the document feeder of Fig. 2 at the time when the document is reversely fed in the double-

Fig. 6 is a schematic sectional view of the document feeder of Fig. 2 at the time when the back side of the document is read in the both-

Fig. 7 is a schematic cross-sectional view of the document feeder of Fig. 2 at the time point when one end of the document is re-entered into the paper discharge section in the double-sided reading mode.

Description of the Related Art [0002]

100: document feeder 110: paper feed unit

111: Pickup roller 113: ADF roller

115: driven roller 117: drive roller

120: reading unit 130:

131: first paper discharge roller 133: second paper discharge roller

140: conveyance relay unit 150: double-sided reading guide

154: Badge passage entrance blocking member 200:

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus improved in an output unit.

1 is a schematic cross-sectional view of an automatic document feeder which is mounted on an upper portion of a conventional image forming apparatus and automatically feeds a document D to a reading section 20. [ For reference, FIG. 1 is disclosed in Japanese Laid-Open Patent Publication No. 9-86807 (hereinafter referred to as "prior invention").

In the case of the one-side reading mode in which only one side of the original D is read, the original placed on the original placement table 8 is picked up by the pickup roller 11 and the picked-up original is conveyed by a plurality of conveying rollers 12, To the reading unit 20. The original read by the reading unit 20 is conveyed to the discharge unit 13 along the discharge path G opened by the switching guide 23. The paper discharge unit 13 is composed of a drive roller 13a and a driven roller 13b interlocked with each other and grasps the delivered original and discharges it to the outside as the drive roller 13a rotates forward.

On the other hand, in the case of the double-sided reading mode in which both sides of the original are read, the original read out on one side along the discharge path G opened by the switching guide 23 is transferred to the discharge unit 17. When the document is completely out of the paper path G, the paper discharge unit 17 reversely rotates (K) and transports the gripped paper in the reverse direction (L direction). At this time, the switching guide 23 blocks the sheet discharging path G so that the sheets conveyed in the reverse direction are prevented from entering the sheet discharging path G again. Thereby, the original is passed between the pair of double-sided reading guides 15 and held on the conveying roller 14 again.

The conveying roller 14 conveys the original to the reading unit 20 and the back side of the original is read by the reading unit 20. The switching guide 23 again opens the delivery path G so that the originals read on both sides pass through the delivery path G and proceed to the delivery part 17. [ Then, the two-sided original is discharged to the outside by the discharge unit 17 that performs forward rotation (J). Here, it is general to shorten the length of the double-sided reading guide 15 so that the set size of the document transporting apparatus can be made compact.

Therefore, in the double-sided reading mode, the leading end of the original again enters the discharge unit 17 in a state in which the rear end of the original to be transported in the reverse direction L is held by the discharge unit 17. As a result, the leading edge of the document is simultaneously gripped by the paper discharge unit 17, and the document may be damaged. Therefore, in the prior art, when the leading edge of the document again enters the paper discharge section 17, the driven roller 17b is disengaged from the drive roller 17a to be spaced apart by a predetermined distance in order to prevent the document from being damaged. A drive device for a driven roller 17b for selectively engaging the driven roller 17b with the drive roller 17a to cause the nip to be nipped and unbucked from the drive roller 17a need.

Therefore, the driving structure of the discharge unit 17 becomes complicated, and the cost of the product increases.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a document transporting apparatus and an image forming apparatus which can simplify the structure of a paper sheet portion.

Another object of the present invention is to provide a document feeder and an image forming apparatus which can reduce the cost of a product.

The above object is achieved by a document feeding apparatus according to the present invention, comprising: a paper feeding unit which grips a document and feeds the document in a predetermined feeding direction to pass through a predetermined target position; A first sheet discharge roller disposed along the first sheet discharge roller axis and a second sheet discharge roller disposed along the second sheet discharge roller axis in parallel to the first sheet discharge roller axis with a manuscript passed through the target position interposed therebetween, And a paper discharge unit having a second discharge roller disposed therein.

The apparatus may further include a driving unit for rotating the first discharging roller in normal and reverse directions and rotating the second discharging roller in a direction opposite to the first discharging roller.

In addition, the first discharge rollers may be provided in plurality and are spaced from each other along the first discharge roller axis, and the second discharge rollers may be plural.

The apparatus may further include a double-sided reading guide for guiding the document to be conveyed reversely along the reverse conveying path branched from the conveying path from the reading unit to the conveying unit, from the conveying unit to the paper feeding unit.

In addition, the double-sided reading guide may include a sheet path entrance blocking portion protruding toward the sheet discharging portion so that the width of the reversing conveying path is greater than the width of the sheet discharging path, and blocking the entry of the original into the sheet discharging path.

In this case, in the double-sided reading mode, one end portion of the manuscript read by the sheet feeding portion is reversely transferred in the reverse direction of the sheet feeding direction, and at the time when one end portion of the manuscript again enters the sheet discharging portion, And a controller for controlling the driving unit.

The first discharge roller and the second discharge roller may be arranged to rotate at the same linear velocity.

Further, the above object is also achieved by an image forming apparatus according to the present invention, comprising: the document conveying device; And a reading unit arranged at the target position to read the document.

Hereinafter, a preferred embodiment of the document feeder 100 and the image forming apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

2, the document feeder 100 according to the present invention includes a main body 101, a document table 103 on which a document D is placed, and a document D to a reading unit 200, A paper feeding unit 110 for feeding the document to the paper feeding unit 110 and a paper feeding unit 200 for feeding the document to the paper feeding unit 110; And a reading guide 150.

The paper feed unit 110 is provided to feed the original D along a predetermined feeding direction (P1 in Fig. 4).

The sheet feeding unit 110 includes a pickup roller 111, a feeding roller 113, a sheet conveying preventing member 116, a driven roller 115, and a driving roller 117. The pick-up roller 111 picks up the original of the original placement table 103. The picked-up original is separated into a sheet by the conveying roller 113 and the conveyance preventing member 116, 115, and 117, respectively. The carriage preventing member 116 may be provided with a friction pad made of a rubber material. The driven and driven rollers 115 and 117 of the paper feeding unit 110 transfer the document to the reading unit 200 side.

The discharge unit 130 receives power from a driving unit (not shown) to be described later. In the single-sided reading mode in which one side of the original is read, the sheet discharger 130 feeds the original outward along the sheet feeding direction (P1 in FIG. 4), and in the double-side reading mode in which both sides of the original are read, The paper is reversely conveyed in the reverse direction of the sheet conveying direction so that the original is re-fed to the sheet feeding units 115 and 117. Accordingly, the discharge unit 130 is provided to be rotatable in the forward and reverse directions so that the original can be transported and reversely transported.

2 and 3, the paper output unit 130 includes a first paper discharge roller shaft 131a, a first paper discharge roller 131, a second paper discharge roller shaft 133a, and a second paper discharge roller 133, .

The first discharge roller shaft 131a and the second discharge roller shaft 133a are rotatably supported by the main body 101 as shown in FIG. The axis C1 of the first delivery roller shaft 131a and the axis C2 of the second delivery roller shaft 133a are parallel to each other and the axis of the first delivery roller shaft 131a and the axis of the second delivery roller shaft 133a are parallel to each other and between the first delivery roller 131 and the second delivery roller 133 The interval between the axes C1 and C2 can be appropriately determined so that the original can be interposed between the axes C1 and C2.

The first discharge rollers 131 are spaced apart from each other along the longitudinal direction on the first discharge roller shaft 131a. It may be one if necessary.

The second paper discharge roller 133 is disposed on the second paper discharge roller shaft 133a so as to be offset from the first paper discharge roller 131 along the lengthwise direction of the second paper discharge roller shaft 133a. Accordingly, as shown in FIG. 3, since the first discharge roller 131 and the second discharge roller 133 are not engaged with each other, a nip is not formed. The conveying force for conveying the original sandwiched between the first paper discharge roller 131 and the second paper discharge roller 133 is transmitted to the first discharge roller 131 by the first frictional force F1 between the first discharge roller 131 and the document, And the second frictional force F2 between the second paper discharge roller 133 and the original. Here, the directions of the first frictional force F1 and the second frictional force F2 shown in Fig. 3 are the force direction at the time of conveying the medium, and are opposite to those shown at the time of reverse conveyance.

On the other hand, in order to minimize the loss of the transfer force by matching the directions of the first and second frictional forces F1 and F2, the rotational directions of the first and second discharge rollers 131 and 133 It is preferably in the opposite direction. That is, the first paper discharge roller 131 is rotatable in the forward and reverse directions, and the second paper discharge roller 133 is rotatable in the direction opposite to the rotating direction of the first paper discharge roller 131. This is because when the first discharge roller 131 and the second discharge roller 133 are connected to each other by a gear (not shown) from a driving unit (not shown) to be described later, the number of the gears is made odd and even And can be realized by differently.

On the other hand, it is preferable that the first discharge roller 131 and the second discharge roller 133 are provided so that their linear velocities are equal to each other. So that the first frictional force F1 and the second frictional force F2 can be used as the transfer force with little loss. When the radial velocities of the first discharge rollers 131 and the second discharge rollers 133 are set to be equal to each other and the linear velocities are made equal to each other, it is also advantageous for component compatibility.

2 and 4, the double-sided reading guide 150 guides the original conveyed backward by the sheet discharger 130 to the driven roller 115 and the driving roller (not shown) of the paper feeding unit 110 117) for guiding the reversed transfer path (U). The double-sided reading guide 150 may include an upper guide 151 and a lower guide 153.

As shown in FIG. 5, the double-sided reading guide 150 may further include an exhaust path entry blocking portion 154. The discharge path entrance blocking portion 154 protrudes toward the discharge portion 130 so that the width H2 of the reverse transfer path U is wider than the width H1 of the discharge path R. 5, the reference numeral S denotes a trajectory in which the one end Da of the original D moves during the backward conveyance. The exit path entry blocking portion 154 is a portion in which one end Da of the original D is moved As shown in FIG. Thus, as the one end Da contacts the lower guide 153, the original D is conveyed along the reverse conveying path U without entering the evacuation path R. [ Accordingly, in the present invention, since it is not necessary to use the switching guide of the past used in the prior art, the structure of the document feeding apparatus can be simplified and the material cost can be reduced.

The original transporting apparatus 100 further includes a driving unit (not shown) for driving the first discharging roller 131 and the second discharging roller 133 to rotate. The driving unit (not shown) may include an electric motor (not shown). The driving unit (not shown) may further include a gear (not shown) for transmitting the power of the electric motor to the first discharge roller 131 and the second discharge roller 133.

The document transporting apparatus 100 may further include an exhaust route guide 160 forming the exhaust route R. [

2, the original transporting apparatus 100 according to the present invention is configured to transport a manuscript read by the reading unit 200 to one side of the delivery path R to the delivery unit 130 And may further include a transfer relay unit 140 for relaying. The transfer relay unit 140 may be omitted if necessary. The transfer relay unit 140 includes a first transfer relay roller 141 and a second transfer relay roller 143 interlocked with each other.

The reading unit 200 may be a CCD (Charge Coupled Device) sensor or a CIS (Contact Image Sensor), which is widely known as reading means. Lt; / RTI >

In addition, the document feeding apparatus 100 further includes a control unit (not shown) for controlling the driving unit so that a one-side reading process and a two-side reading process are performed. The control unit (not shown) may control the paper feeding unit 110 and the transfer relay unit 140 in addition to the driving unit. The function of the control unit (not shown) will be described in detail in a one-side reading process and a two-side reading process, which will be described later.

The process of reading one side of the original D will be described in detail with reference to FIG.

First, the pick-up roller 111 picks up the original D on the original placement table 103. The picked-up original is separated into sheets by the conveying roller 113 and the conveyance preventing member 116 to be separated from the driven roller 115, And is transferred to the reading unit 200 by the driving roller 117.

After the one side is read by the reading unit 200, the transferred original is transferred to the discharge unit 130 by the transfer relay unit 140 while passing between the discharge path guide 160. The control unit controls the driving unit such that the first roller 131 of the paper discharge unit 130 rotates the forward rotation A1 and the second roller 133 rotates backward to rotate the first roller 131 and the second roller 133, 2 rollers 133 are discharged to the outside.

5 to 7 illustrate a process in which the document of the document feeder of FIG. 2 is reversely transferred to the reversal conveyance path U to read the back side of the document, reenter the document to the discharge unit 130, And is a schematic cross-sectional view sequentially.

In the case of the double-sided reading mode, the original D is fed along the feeding direction P1 shown in Fig. 4 as in the single-sided reading mode described above to read one side of the original. 5, the control unit (not shown) rotates the first discharge roller 131 to the forward rotation A1 and the second discharge roller 131 to rotate the first discharge roller 131 until the original D completely flows out of the discharge path R. At this time, (B1). Thus, one end portion Da of the original D is moved out of the delivery path R and interposed between the first delivery roller 131 and the second delivery roller 132.

5, in a state in which one end Da of the original D is interposed between the first delivery roller 131 and the second delivery roller 133, the control unit (not shown) The roller 131 is reversely rotated (A2) and the second paper discharge roller 133 is rotated forward (B2). Accordingly, the original D is conveyed in the reverse direction P2 in the sheet feeding direction (P1 in Fig. 4) as shown in Fig. The original D to be conveyed backward is conveyed along the reverse conveying path U while one end Da contacts the lower guide 153 of the double-sided reading guide 150 and is conveyed again to the driven roller 115 of the paper feeding unit 110, And the drive roller 117, as shown in Fig. 6, the original D is gripped again by the paper feeding unit 110 and passes through the reading unit 200 in a state in which the back surface of the read surface thereof faces the reading unit 200 . Accordingly, the back surface is read by the reading unit 200.

7, when the one end Da of the original D enters the discharge unit 130 again, the control unit (not shown) (Not shown) so that the rollers 131 and 133 are in an idle state. This can be realized by turning off the power of the driving unit (not shown) or preventing the power of the driving unit (not shown) from being transmitted to the discharge unit. If the first discharge roller 131 is rotated in the reverse direction A2 and the second discharge roller 133 is rotated in the forward direction B2, the one end portion Da of the original D is separated from the first discharge roller 131 and / This is to prevent this because it may not be easy to enter between the second discharge roller 133 and the second discharge roller 133.

Since the driving force for conveying the original D can be obtained from the paper feeding units 115 and 117 and the conveyance relay unit 140, there is no problem in conveying the original D even if the discharging unit 130 is idled. This is because the nip is formed in the paper feeding units 115 and 117 and the conveyance relay unit 140 and the original D is gripped and conveyed so that it is larger than the conveyance force of the paper discharge unit 130 in terms of the conveying force.

Meanwhile, a separate paper detection sensor 170 can be installed on the side where the document enters the paper discharge unit 130, thereby detecting the point of time when the paper discharge unit 130 re-enters the one end portion Da of the document. Alternatively, it is also possible to estimate the entry point of the discharge unit 130 at one end Da by estimating the position of the one end Da by sensing the number of revolutions of the discharge unit 130. In addition, it is also possible to detect or estimate the entry point by other known methods.

One end Da of the original D is supported by the first and second discharge rollers 131 and 133 of the discharge portion 130 while the other end Db of the original D is interposed in the discharge portion 130. [ The nip is not formed in the paper discharge unit 130, so that the original D is not damaged.

The control section (not shown) controls the other end portion Db of the document D from the time when one end Da of the document D is held by the driven and driven rollers 115 and 117 of the paper feeding section 110, May be maintained in an idle state until a time when the sheet discharging unit 130 is detached from the sheet discharging unit 130. The transfer force can be obtained from the driven and driven rollers 115 and 117 and the transfer relay unit 140. [ Accordingly, the power consumption can be reduced by not driving the discharge unit 130 for a predetermined period of time. However, from the point of time when the other end Db of the original D is separated from the conveyance relay unit 140, the discharge unit 130 should be caused to deliver the medium.

If there is no transfer relay unit 140, the discharge unit 130 is idle until the other end Db of the original D is separated from the driven and driven rollers 115 and 117, , And after that, the delivery unit 130 can perform delivery of the medium.

The control unit (not shown) controls the discharge unit 130 from the time when the other end Db of the original D is separated from the discharge unit 130 and one end Da is interposed in the discharge unit 130 So that the conveyance of the medium for discharging the original D to the outside can be performed. At this time, since both the driven and driven rollers 115 and 117 of the paper feeding unit 110, the transfer relay unit 140 and the discharge unit 130 are driven to feed the original D, the original D is driven at a high speed You can send it out. Thus, the feeding speed of the original D can be improved and the original reading speed can be improved.

Meanwhile, an image forming apparatus (not shown) according to the present invention includes the document feeding device 100 and a reading unit 200. The image forming apparatus (not shown) may further include a printing unit (not shown) for printing the image data read by the reading unit 200 on the printing paper, such as a so-called multifunction apparatus. The printing unit (not shown) may include a head having a plurality of nozzles in the case of the inkjet method, and a developing unit for developing the photoreceptor and the photoreceptor in the case of electrophotography.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the scope of the present invention should be determined by the appended claims and their equivalents.

As described above, according to the document transporting apparatus and the image forming apparatus including the same according to the present invention, the following effects can be obtained.

First, the drive structure of the discharge section can be simplified. This makes it possible to significantly reduce the possibility of failure of the discharge unit. In the prior art, the driving structure of the discharge portion is complicated by driving any one of the discharge rollers so as to be spaced apart from and in contact with the other discharge roller.

Secondly, since separate driving means for separating and contacting any one of the discharge rollers to the other is not required, the material cost can be reduced.

Thirdly, since the means for driving the switching guide and the switching guide of the prior invention is not required, the document feeding apparatus can be realized with a simpler structure. Thus, the material cost can be further reduced.

Claims (8)

In the document feeder, A paper feeding unit which grips the document and feeds the document in a predetermined feeding direction to pass through a predetermined target position; A reading unit that reads the original sent from the paper feeding unit; A first sheet discharge roller disposed along the first sheet discharge roller axis and a second sheet discharge roller disposed along the second sheet discharge roller axis in parallel to the first sheet discharge roller axis with a manuscript passed through the target position interposed therebetween, A discharge portion having a second discharge roller disposed therein; And a double-sided reading guide for guiding a document, which is reversely fed along an inversion conveying path branched from the sheet discharging path from the reading unit to the sheet discharging unit, from the sheet discharging unit to the sheet feeding unit, Wherein the double-sided reading guide includes an ejection path entrance blocking portion protruding toward the ejection portion so that the width of the reversing conveyance path is larger than the width of the ejection path, and blocking the entry of the original into the ejection path. Conveying device. The method according to claim 1, And a driving unit that rotates the first paper discharge roller in the forward and reverse directions and rotates the second paper discharge roller in a direction opposite to the first paper discharge roller. 3. The method of claim 2, Wherein the plurality of first discharge rollers are spaced apart from each other along the first discharge roller axis, and the second discharge rollers are plural. delete delete The method according to claim 2 or 3, In the case of the double-sided reading mode, one end of the manuscript read by the sheet feeding section is reversely transferred in the reverse direction of the sheet feeding direction, and at the time when one end of the manuscript again enters the sheet discharging section, And a control unit for controlling the document conveying unit. 4. The method according to any one of claims 1 to 3, Wherein the first discharge roller and the second discharge roller are provided so as to rotate at the same linear velocity. In the image forming apparatus, A document feeder according to any one of claims 1 to 3; And reading means arranged at the target position for reading the document.

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