JP2017017466A - Automatic document feeder, image reading device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispose a pressing member for pressing a document without involving an increase in size of an ADF housing, and make it possible to open a guide member while the pressing member is attached to the housing.SOLUTION: A document conveyance path of an ADF is partially formed of a guide member 120. The guide member 120 is rotatably attached with a rotation shaft 121 provided in an ADF housing 110 as the center in order to open the document conveyance path to the outside. A pressing member 130 pressing a document 1 in a stationary reading system is held on a housing lower face 111 to be able to move in the vertical direction. One end of the pressing member 130 is connected to the guide member 120. The pressing member 130 is moved in the vertical direction with respect to the housing 110 in conjunction with rotation of the guide member 120.SELECTED DRAWING: Figure 3

Description

The present invention relates to an automatic document feeder mounted on an image forming apparatus such as a copying machine or an image reading apparatus, and an image reading apparatus and an image forming apparatus provided with the automatic document feeder.

Conventionally, an automatic document feeder (hereinafter referred to as “ADF”) capable of a sheet-through method and a fixed reading method (pressure plate method) is known. In the sheet-through method, image reading is performed while a sheet document is conveyed by a fixed reading unit. In the fixed reading method, an original (including a book original) is stationary on a contact glass, and the reading unit is moved to read an image. The ADF has a housing that can be opened and closed on the contact glass, and a pressure plate (hereinafter referred to as a “pressing member”) for pressing a document placed on the contact glass is disposed on the lower surface of the housing. Yes.

On the other hand, a guide member for scooping up the sheet document in the sheet-through method is disposed on the lower surface on one side of the ADF casing. The guide member constitutes a part of the document conveyance path, and the rotation axis provided in the housing is centered so that the document conveyance path can be opened during maintenance such as document jam processing and roller cleaning. It is pivotally attached.

Due to the structure of the ADF casing, there is no method other than attaching the pressing member to the guide member. For this reason, when opening the guide member at the time of document jam processing and maintenance, it is necessary to remove the pressing member from the ADF casing. It was. Further, when the pressing member is attached to and detached from the housing, the possibility of the positional deviation of the pressing member increases.

Therefore, various configurations have been proposed that allow the guide member to be opened and closed without attaching or detaching the pressing member. For example, in the technique described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-278174), the pressing member is composed of a sheet-like elastic member. The front end side of the sheet-like elastic member is connected to the lower surface of the guide member, and the rear end side of the sheet member is attached to be slidable in the horizontal direction with respect to the ADF housing. When the guide member is rotated to the open side, the sheet-like elastic member is configured to slide along the lower surface of the ADF casing.

In the technique of Patent Document 1 (Japanese Patent Laid-Open No. 2002-278174), since the sheet-like elastic member is slidably attached to the ADF casing, it is necessary to increase the size of the ADF casing by the amount of sliding. This led to an increase in machine size. The present invention has been made in view of the above problems, and its purpose is to dispose the pressing member without increasing the size of the ADF casing and to release the guide member while the pressing member remains attached to the casing. Is to make it possible.

In order to solve the above-described problems, an automatic document feeder according to the present invention includes a fixed reading method for reading an image of a stationary document while moving a reading unit, and an image reading while conveying the document while fixing the position of the reading unit. An automatic document conveyance device applied to an image reading apparatus compatible with a sheet-through method to be performed, and a casing having a document conveyance path for conveying a document in the sheet-through method, and a part of the document conveyance path And a guide member rotatably attached to the housing about a rotation shaft provided in the housing so that the document conveyance path can be opened to the outside, and the guide member A pressing member that is held by the casing at an adjacent position and presses the document in the fixed reading method, and holds the pressing member so as to be movable up and down with respect to the casing. In addition, by connecting one end portion of the pressing member to the guide member at a position spaced from the rotation shaft, the pressing member is moved in the axial direction of the rotation shaft in conjunction with the rotation of the guide member. It is configured to move up and down with respect to the casing in a direction perpendicular to the casing.

According to the present invention, since the pressing member is configured to move up and down relative to the casing in conjunction with the rotation of the guide member, the pressing member can be disposed without increasing the size of the casing. In addition, the guide member can be opened while the pressing member is attached to the housing.

1 is a schematic configuration diagram of a document reading apparatus according to an embodiment of the present invention. 3 is a block diagram illustrating a configuration example of a control unit of the image reading apparatus according to the embodiment of the present invention. FIG. It is sectional drawing which shows the up-and-down moving mechanism of the press member of the image reading apparatus of 1st Embodiment of this invention. It is sectional drawing which shows the up-and-down moving mechanism of the press member of the image reader of 2nd Embodiment of this invention. It is sectional drawing which shows the up-and-down moving mechanism of the press member of the image reading apparatus of 3rd Embodiment of this invention. It is sectional drawing which shows the up-and-down moving mechanism of the press member of the image reading apparatus of 4th Embodiment of this invention. It is sectional drawing which shows the up-and-down moving mechanism of the press member of the image reading apparatus of 5th Embodiment of this invention. It is sectional drawing which shows the up-and-down moving mechanism of the press member of the image reader of 6th Embodiment of this invention. It is sectional drawing which shows the up-and-down moving mechanism of the press member of the image reader of 7th Embodiment of this invention.

(Original reading device)
A document reading apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a document reading apparatus. This document reading apparatus includes a sheet feeding unit (document setting unit A), an ADF (separate feeding unit B, timing unit C, turn unit D), and scanner units (first reading conveyance unit E, second reading conveyance unit). F), a discharge part G, and a stack part H. This document reading apparatus is configured by a document reading apparatus alone or mounted on, for example, a printer as a part of the image forming apparatus.

As shown in FIG. 2, the document reading apparatus includes motors 101 to 105 that drive the respective parts A to H, various sensors (5, 6, 8, 11, 13, 15, 17, 24), A controller 100 that controls a series of operations is provided. The controller 100 can be connected to a printer or the like as an image forming apparatus via the I / F 107.

1 has a fixed document table 2 and a movable document table 3. These tables 2 and 3 are arranged adjacent to each other in the front-rear direction (document transport direction) at the top of the document reading apparatus. A document bundle 1 including a single-sided document or a double-sided document to be read is set on the tables 2 and 3 with the document surface facing upward. The width direction of the document bundle 1 is positioned by a side guide in a direction orthogonal to the conveyance direction.

On the table surface of the fixed document table 2 on the rear side, document length detection sensors 30 and 31 are disposed apart from each other in the front-rear direction. As the document length detection sensors 30 and 31, a reflection type sensor or an actuator type sensor capable of detecting even one document can be used. The document length detection sensors 30 and 31 are arranged to detect at least whether a document of the same size is set vertically or horizontally on the fixed document table 2. The document length detection sensors 30 and 31 detect the approximate length in the document transport direction. The setting of the document is detected by the set filler 4 and the set sensor 5, and is transmitted to the main body control unit 120 such as a printer by the I / F 107.

The front movable document table 3 can be moved up and down in directions a and b in FIG. 1 by a bottom plate raising motor 105 (see FIG. 2). A pickup roller 7 is disposed above the movable document table 3. The pickup roller 7 operates in the vertical direction (c and d directions) in FIG. 1 by a pickup motor 101 (see FIG. 2) and a cam mechanism.

When the set sensor 5 detects that the document is set on the document setting portion A, the bottom plate raising motor 105 is rotated forward to raise the movable document table 3, and the uppermost surface of the document bundle 1 comes into contact with the pickup roller 7. . When the pickup roller 7 is pushed on the upper surface of the document and raised in the c direction, the upper limit of the rise is detected by the table rise detection sensor 8.

When the table elevation detection sensor 8 detects the upper limit of the elevation, the bottom plate raising motor 105 is stopped, and then the bottom plate raising motor 105 is rotated forward again when the uppermost surface of the document bundle 1 is lowered due to the supply of documents. In this way, the bottom plate raising motor 105 repeats normal rotation and stop, so that the uppermost surface of the original bundle is always maintained at an appropriate height. When all the originals set in the original setting part A are fed, the bottom plate raising motor 105 is reversed and the movable original table 3 is lowered to the home position so that the next original bundle can be set in the original setting part A. The

The user sets the duplex mode or the simplex mode by pressing a key. In this setting, the same setting may be made for all the documents set in the document setting portion A, or different settings may be made for each document (for example, in all 10 documents, The first and tenth sheets are in double-sided mode, and the other is single-sided mode).

After the setting, when the user presses the print key of the operation unit 108 in FIG. 2, a document feed signal is transmitted from the main body control unit 120 to the controller 100 of the document reading apparatus via the I / F 107. As a result, the pickup roller 7 is rotationally driven by the normal rotation of the paper feed motor 102, and one or several originals on the original table 2 are picked up. The rotation direction of the pickup roller 7 is a direction in which the uppermost document is conveyed to the sheet feeding port.

Although it is ideal that the number of pick-ups is always one at this time, several originals may be picked up and conveyed (multi-feed) to the paper feed port unexpectedly due to friction between papers. Such double feeding is prevented by a reverse roller 10 described later.

The separation feeding unit B includes a paper feeding belt 9 that is stretched between a pair of rollers, and a reverse roller 10 that is in contact with the lower side of the paper feeding belt 9. The paper feeding belt 9 is driven in the paper feeding direction by the normal rotation of the paper feeding motor 102 (see FIG. 2), and the reverse roller 10 is rotated in the direction opposite to the paper feeding direction through the torque limiter by the normal rotation of the paper feeding motor 102. Driven. Then, the uppermost original and the second and subsequent originals below are separated between the paper feed belt 9 and the reverse roller 10, and only the uppermost original is conveyed downstream by the paper feed belt 9. Is configured to feed paper.

Specifically, the reverse roller 10 is in contact with the lower surface of the paper feeding belt 9 at a predetermined pressure, and when the paper is in direct contact with the paper feeding belt 9 or through only one original, the rotation of the paper feeding belt 9 is rotated. Accordingly, it rotates in the counterclockwise direction in FIG. Further, when two or more originals enter between the paper feed belt 9 and the reverse roller 10, the follower force is set to be lower than the torque limiter torque.

With this setting, the reverse roller 10 rotates in the clockwise direction, which is the original driving direction in FIG. By rotating the reverse roller 10 in the clockwise direction, the second and subsequent originals are pushed back in the direction opposite to the conveying direction, thereby preventing the double feeding of the originals.

The timing unit C includes an abutment sensor 11 and a pull-out roller 12 that is driven by the reverse rotation of the paper feed motor 102. The pull-out roller 12 and a plurality of rollers on the downstream side are all configured as a pair of two rollers with a conveyance path interposed therebetween. The timing unit C aligns the front ends of the documents that are separated and conveyed one by one from the separation feeding unit B by primary abutting against the pull-out roller 12, and pulls out the aligned document by the pull-out roller 12 at a predetermined timing. It is conveyed to the intermediate roller 14.

That is, the original document separated into one sheet by the action of the paper feed belt 9 and the reverse roller 10 is sent to the timing portion C side by the paper feed belt 9, and after the front end is detected by the abutting sensor 11, It strikes against the pull-out roller 12 that has stopped. Thereafter, the document is fed by a predetermined amount from the detection of the abutting sensor 11, and the paper feed motor 102 is stopped while being pressed against the pull-out roller 12 with a predetermined amount of bending, thereby feeding the paper. The driving of the belt 9 is stopped.

At this time, by rotating the pickup motor 101, the pickup roller 7 is retracted from the upper surface of the document, and the document is fed only by the conveying force of the paper feeding belt 9, so that the front end of the document is in the nip of the pair of upper and lower rollers of the pullout roller 12. The front end is aligned (skew correction). Note that the length of the document in the conveyance direction is detected by reading the front and rear ends of the document with the abutment sensor 11 and counting the pulses of the paper feed motor 102 between them.

The pull-out roller 12 has a skew correction function, and is a roller for conveying the skew-corrected document after separation to the intermediate roller 14, and is driven by reverse rotation of the paper feed motor 102. When the paper feed motor 102 is rotated in reverse, the pull-out roller 12 and the intermediate roller 14 are driven, but the pickup roller 7 and the paper feed belt 9 are not driven.

A document width sensor 13 is disposed between the pull-out roller 12 and the intermediate roller 14. A plurality of document width sensors are arranged in the depth direction of FIG. 1 and detect the size in the width direction orthogonal to the transport direction of the document transported by the pull-out roller 12.

The turn part D has an intermediate roller 14, and the document conveyed from the timing part C is turned downward by the intermediate roller 14, and the first surface (front surface) of the document is conveyed toward the reading side (downward). The document is conveyed from the timing unit C to the turn unit D. By setting the conveyance speed at the timing unit C to be higher than the conveyance speed at the first reading conveyance unit E, the original is conveyed to the first reading conveyance unit. The processing time sent to E is shortened.

The first reading conveyance unit E includes a reading inlet roller 16 and a reading outlet roller 23 before and after the reading position 20. A predetermined first document reading unit is disposed below the reading position 20, and the surface of the document is read by the first document reading unit. A reading entrance sensor 15 is disposed between the reading entrance roller 16 and the intermediate roller 14 on the upstream side thereof.

When the front end of the document is detected by the reading entrance sensor 15, the transport is performed so that the document transport speed is the same as the reading transport speed before the front end of the document enters the nip between the upper and lower rollers of the reading entrance roller 16. Deceleration of speed is started. Simultaneously with the deceleration, the reading motor 103 is driven to rotate forward, and the reading inlet roller 16, the reading outlet roller 23, and the second reading portion outlet roller 27 are driven.

When the front edge of the document is detected by the timing sensor 17 on the downstream side of the reading entrance roller 16, the conveyance speed is reduced over a predetermined conveyance distance, and the document is temporarily stopped before the reading position 20. At the same time, a timing stop signal is transmitted from the controller 100 to the main body control unit 120 via the I / F 107.

Subsequently, when the controller 100 receives a reading start signal from the main body control unit 120, a gate signal indicating an effective image area in the sub-scanning direction on the first surface is sent to the main body control unit 120, and the document trailing edge indicates the reading position 20. It is transmitted continuously until it exits. The transmission of the gate signal starts at the timing when the front end of the document 1 that has been stopped reaches the reading position 20. The document 1 is accelerated to rise to a predetermined conveyance speed and conveyed to the reading position 20, and the timing at which the front end of the document reaches the reading position 20 is detected by the pulse count of the reading motor 103.

The document that has passed through the first reading and conveying unit E is conveyed to the second reading and conveying unit F. A paper discharge sensor 24 is disposed between the first reading conveyance unit E and the second reading conveyance unit F, and the rotation speed of a paper discharge roller 28 described later is adjusted by the paper discharge sensor 24.

The second reading / conveying unit F includes a second reading unit 25 and a second reading unit outlet roller 27, while the original 1 is being conveyed by the reading outlet roller 23 and the second reading unit outlet roller 27, while the second reading unit 25 reads the second side (back side) of the document from above. A second reading roller 26 that suppresses the floating of the document is disposed at a position facing the second reading unit 25. The second reading roller 26 also serves as a reference white part for acquiring shading data for shading correction in the second reading unit 25.

In the case of double-sided document reading, the timing at which the front end of the document reaches the second reading unit 25 is detected by the pulse count of the reading motor 103 after the discharge sensor 24 detects the front end of the document. At the arrival timing, transmission of a gate signal indicating an effective image area in the sub-scanning direction is started from the controller 100 to the second reading unit 25, and the signal continues until the trailing edge of the document exits the second reading unit 25. Sent.

The document that has been read only on the first surface by the first reading and conveying unit E and the document that has also been read on the second surface by the second reading and conveying unit F are discharged to the stack unit H through the discharge unit G. A paper discharge roller 28 is disposed in the discharge portion G. When the front end of the original is detected by the paper discharge sensor 24, the paper discharge motor 104 is driven to rotate forward and the paper discharge roller 28 is counterclockwise in FIG. To be rotated.

In addition, the discharge motor drive speed is reduced immediately before the trailing edge of the original comes out of the nip of the upper and lower roller pairs of the discharge roller 28 by the discharge motor 104 pulse count from the detection of the front edge of the original by the discharge sensor 24. This deceleration prevents the document from jumping out of the paper discharge tray 29. The slowed document is discharged to the stack portion H by the paper discharge roller 28 and is stacked and held on the stack portion H.

(Guide member and pressing member)

In the ADF having the second reading and conveying unit F as shown in FIG. 1, a part of the document conveying path where the second reading and conveying unit F is located is configured by a guide member 120 that can rotate with respect to the ADF housing 110. Yes. Then, by removing a predetermined locking mechanism of the ADF, the document conveyance path can be opened by rotating downward about a rotation shaft 121 (see FIGS. 3 to 9) provided in the housing 110. . By opening the document conveyance path in this way, it is possible to perform maintenance such as document jam processing and cleaning of the second reading unit 25.

A pressing member 130 is provided on the lower surface 111 of the ADF housing 110 to press a document (including a book document) against the contact glass during the fixed reading method (pressure plate method). The pressing member 130 is held by the ADF housing 110 at a position adjacent to the guide member 120. In the embodiment of the present invention, the pressing member 130 is held so as to be movable up and down with respect to the ADF housing 110.

In the embodiment of the present invention, as shown in the following first embodiment (FIG. 3) to seventh embodiment (FIG. 9), the pressing member 130 is moved up and down in conjunction with the rotation of the guide member 120. It is composed. Therefore, it is possible to save the trouble of once removing the pressing member 130 each time the guide member 120 is opened, and to eliminate the possibility of the positional displacement of the pressing member 130.

In addition, when the guide member 120 is opened, the pressing member 130 is lowered toward the lower space of the ADF casing 110. Therefore, for avoiding the interference with the guide member 120 as in the conventional case, the pressing member 130 is for avoiding movement. There is no need to provide a special space in the housing, and the machine size does not increase. Hereinafter, the pressing member 130 and its vertical movement mechanism will be described with reference to the first embodiment (FIG. 3) to the seventh embodiment (FIG. 9). In the following description, the left end of the pressing member 130 in FIGS. 3 to 9 is referred to as “front end”, and the right end is referred to as “rear end”.

(First embodiment)
FIGS. 3A and 3B show the pressing member 130 and its vertical movement mechanism of the document reading apparatus according to the first embodiment. The pressing member 130 is held on the lower surface 111 of the ADF housing 110 so as to be movable up and down via the vertical movement mechanism. Further, the guide member 120 has a substantially triangular shape in a side view, and the front end of the document is scooped up by a scooping surface 120a on the upper surface with the pointed left end.

The pressing member 130 has an upper and lower two-plate structure including an upper supporting plate 131 and a lower pressing white plate 132. The upper support plate 131 is a relatively rigid material, and the lower pressed white plate 132 is a relatively soft and elastic material. Since the pressed white plate 132 is in direct contact with the original by a fixed reading method, it is desirable to use a soft and elastic material. The pressed white plate 132 also serves as a reference white portion for acquiring shading data.

The pressing white plate 132 is detachably attached to the lower surface of the support plate 131 by hook and loop fasteners 133 at the front and rear ends so that the pressing white plate 132 can be easily and inexpensively replaced. By adopting the upper and lower two-sheet structure as described above, it is possible to freely select the material of the pressed white plate 132 while maintaining the necessary strength as the pressing member 130 with the support plate 131. The pressed white plate 132 may be detachably attached with a clip, a magnet, or the like other than the hook-and-loop fastener 133.

The rear end portion of the support plate 131 is swingably connected to the lower surface 111 of the housing 110 by pins P1 and P2 serving as second connection portions, a rotating plate 140, and a bracket 141. The rotating plate 140 and the bracket 141 are disposed at both ends of the document width direction (the front-rear direction in FIG. 3).

The front end portion of the support plate 131 is supported by the guide member 120 by a pin P3 as a first connecting portion and a bracket 122. The brackets 122 are disposed so as to protrude downward at both ends of the document member in the document width direction (front and rear direction in FIG. 3) on the lower surface of the guide member 120 on the document scooping side. The front end portion of the pressing member 130 is rotatably supported with respect to the guide member 120 by the pin P3 supported by the bracket 122. The guide member 120 including the bracket 122 and the rotating plate 140 constitute a “node” of the four-bar linkage mechanism.

In the first embodiment of FIG. 3, the lower surface of the guide member 120 is substantially flush with the ADF housing lower surface 111 and is in a horizontal state as shown in FIG. In this horizontal state, the guide member 120 is locked by a predetermined locking mechanism of the ADF. The guide member 120 is placed in a horizontal state as shown in FIG. 3A, and the document is read by the sheet through method and the pressure plate method.

Further, during maintenance such as document jam processing and roller cleaning, the ADF casing 110 is rotated upward from the contact glass to form a space between the ADF casing and the contact glass. In this state, the guide member 120 is opened as shown in FIG.

That is, the guide member 120 is rotated downward about the rotation shaft 121, and the scooping tip side is lowered downward. As a result, the scooping surface 120a of the guide member 120 is opened, and internal document jam processing and maintenance are performed.

When the guide member 120 is opened, the pressing member 130 moves in parallel below the housing 110 as shown in FIG. Since there is a large space below the housing 110, it is only necessary to move the pressing member 130 into this space, so that it is not necessary to increase the size of the ADF housing as in Patent Document 1.

(Second Embodiment)
4A and 4B show the pressing member 130 and its vertical movement mechanism of the document reading apparatus according to the second embodiment. The second embodiment is the same as the first embodiment of FIG. 3 except that the pressed white plate 132 on the lower side of the pressing member 130 is changed to a pressed white sheet 134. By changing to the pressed white sheet 134, the weight and cost of the ADF can be reduced, and the guide member 120 can be easily opened and closed by the weight reduction.

(Third embodiment)
FIGS. 5A and 5B show the pressing member 135 and its vertical movement mechanism of the document reading apparatus according to the third embodiment. In the third embodiment, the pressing member 135 is simplified by a single-sheet structure rather than a two-sheet structure. That is, the pressing member 135 has a two-layer integrated structure of an upper support plate layer 135a and a lower pressed white layer 135b. By simplifying the pressing member 135 with a single-sheet structure, the cost of the ADF can be reduced by reducing the number of parts. The rest is exactly the same as in the first embodiment of FIG.

(Fourth embodiment)
FIGS. 6A and 6B show the pressing member 130 and its vertical movement mechanism of the document reading apparatus according to the fourth embodiment. In the fourth embodiment, dampers 150 and 151 are provided to softly open / close the guide member 120 and to move the pressing member 130 up and down (relaxing the speed). The rest is exactly the same as in the first embodiment of FIG. The dampers 150 and 151 function as buffer members that attenuate the rotational speed of the guide member 120.

The purpose of attenuating the rotational speed of the guide member 120 with the dampers 150 and 151 is to swiftly turn the guide member 120 downward and damage a finger or the like when the predetermined locking mechanism of the ADF is removed. This is to prevent damage. The damper can be similarly applied to the first to third embodiments described above and the fifth to seventh embodiments described later.

In the illustrated example, the dampers 150 and 151 are disposed on both the rotating shaft 121 and the pin P2, but may be disposed only on either the damper 150 or the damper 151. The speed relaxation effect can be enhanced by providing the damper 150 on the rotation shaft 121 having a large rotation angle.

On the other hand, the parts around the rotation shaft 121 of the guide member 120 are concentrated, and the degree of freedom in design is relatively small. Therefore, the arrangement of the damper 151 on the opposite pin P2 is more effective in avoiding ADF enlargement. In addition to the rotating shaft 121 and the pin P2, the damper can be disposed at the positions of the pins P1 and P3 that have more design freedom.

When the guide member 120 is opened by disposing the damper, the pressing member 130 is also slowly lowered. This reduces the possibility of fingers being pinched between the pressing member 130 and the contact glass. In addition, the possibility of accidentally damaging the contact glass with the guide member 120 or the pressing member 130 is reduced. Further, when the guide member 120 is closed, the pressing member 130 slowly rises, so that the possibility that a finger is caught between the pressing member 130 and the lower surface 111 of the ADF housing 110 is reduced.

(Fifth embodiment)
FIGS. 7A and 7B show the pressing member 130 and its vertical movement mechanism of the document reading apparatus according to the fifth embodiment. In the fifth embodiment, a slide pin P4 attached to the rear end portion of the pressing member 130 is slidably engaged with a horizontal elongated hole 143 of a bracket 142 fixed to the lower surface 111 of the ADF housing 110. . The rest is exactly the same as in the first embodiment of FIG.

The fifth embodiment of FIG. 7 does not use the rotating plate 140 of FIG. 3, so the number of parts can be reduced and the cost can be reduced. In order to improve the slidability of the slide pin P4, the bracket 142 having the horizontal elongated hole 143 and the material of the slide pin P4 may be made of self-lubricating plastic or the like.

(Sixth embodiment)
FIGS. 8A and 8B show the pressing member 130 and its vertical movement mechanism of the document reading apparatus according to the sixth embodiment. In the sixth embodiment, in the fifth embodiment, a convex portion 144 that restrains the position of the slide pin P4 engaged with the horizontal elongated hole 143 is formed on the inner surface of the horizontal elongated hole 143. The rest is exactly the same as in the first embodiment of FIG.

The convex portion 144 can lock the position of the slide pin P4 when the guide member 120 is opened, and the position of the pressing member 130 during jam processing and maintenance is fixed to facilitate the work. Further, it is possible to reduce the possibility that a finger is caught unexpectedly between the pressing member 130 and the lower surface 111 of the ADF housing 110.

The position of the convex portion 144 is on the upper edge side of the horizontal elongated hole 143 at a position returned from one end portion of the horizontal elongated hole 143 to which the slide pin P4 moves when the guide member 120 is opened by an amount equivalent to the diameter of the slide pin P4. is there. The shape of the convex portion 144 is a symmetrical triangular shape having tapered slopes formed on both sides. The slide pin P4 can get over the convex portion 144 on the tapered slope.

A rectangular cutout hole 145 is formed in the bracket 142 corresponding to the position of the convex portion 144. A thin-walled portion is formed between the cutout hole 145 and the convex portion 144, and the convex portion 144 can be elastically moved up and down by elastic deformation of the thin-walled portion.

(Seventh embodiment)
FIGS. 9A and 9B show the pressing member 130 and its vertical movement mechanism of the document reading apparatus according to the seventh embodiment. In the seventh embodiment, brackets 123 are fixed to both ends of the lower surface of the guide member 120 in the document width direction (the front-rear direction in FIG. 9), and the front end of the pressing member 130 is inserted into the horizontal elongated holes 124 formed in the bracket 123. The slide pin P5 provided in the portion is engaged so as to be slidable. Further, a pin P6 provided at the rear end portion of the pressing member 130 is rotatably connected to a bracket 146 provided on the housing lower surface 111. The rest is exactly the same as in the first embodiment of FIG.

Also in the case of the seventh embodiment, when the guide member 120 is opened downward as shown in FIG. 7B, the pressing member 130 rotates downward about the pin P6 at the rear end. At this time, the slide pin P5 slides from one end portion of the horizontal elongated hole 124 to the other end portion.

A convex portion may be formed in the horizontal elongated hole 124 as in FIG. 8 so that the guide member 120 can be locked at the opening position and the pressing member 130 can be locked at the lowered position. Thereby, the position of the pressing member 130 at the time of jam processing and maintenance is fixed and the work is facilitated. Further, it is possible to reduce the possibility that a finger is accidentally pinched between the pressing member 130 and the lower surface of the ADF housing 110.

Further, in the embodiment of FIG. 9, the members that are largely interlocked when the guide member 120 is opened are concentrated on the guide member 120, so that it is difficult to recognize the user when opening the guide member 120. Compared to the case where parts that are largely linked are arranged, the risk of work of pinching or hitting fingers or objects can be reduced.

  As mentioned above, although embodiment of this invention was described, this invention can be variously deformed without being limited to the said embodiment. For example, the pressing members 130 and 135 may be held by the ADF housing 110 so as to be movable up and down, and the vertical movement mechanism is arbitrary. Therefore, in addition to the link support mechanism and the rotation support mechanism of the above-described embodiment, any manual or electric vertical movement mechanism using a cylinder, a gear, a cord-like body, a belt, or the like can be used.

JP 2002-278174 A

1: Document bundle 2: Fixed document table 3: Moveable document table 4: Set filler 5: Set sensor 7: Pickup roller 8: Table lift detection sensor 9: Paper feed belt 10: Reverse roller 11: Sensor 12: Pull-out roller 13: Document width sensor 14: Intermediate roller 15: Reading entrance sensor 16: Reading entrance roller 17: Timing sensor 20: Reading position 23: Reading exit roller 24: Paper discharge sensor 25: Second reading unit 26: Second reading roller 27: First 2 Reading unit exit roller 28: Paper discharge roller 29: Paper discharge tray 30, 31: Document length detection sensor 100: Controller 101: Pickup motor 102: Paper feed motor 103: Reading motor 104: Paper discharge motor 105: Bottom plate raising motor 108: Operation unit 110: ADF casing 111: Under ADF casing 120: Main body control unit 120: Guide member 120a: Scooping surface 121: Rotating shaft 122: Bracket 123: Bracket 124: Horizontal long hole 130: Press member 131: Support plate 132: Press white plate 133: Surface fastener 134: Press white Sheet 135: Pressing member 140: Rotating plate 141: Bracket 142: Bracket 143: Horizontal long hole 144: Convex part 145: Notch hole 146: Bracket 150, 151: Damper A: Document setting part B: Separation feeding part C: Timing part D: Turn part E: Reading conveyance part F: Reading conveyance part G: Discharge part H: Stack part P1-P6: Pin

Claims (9)

An automatic document applied to an image reading apparatus that supports a stationary reading method that reads an image of a stationary document while moving a reading unit and a sheet-through method that reads an image while conveying the document while fixing the position of the reading unit. A conveying device,
A casing having a document conveyance path for conveying a document in the sheet-through method;
A guide that constitutes a part of the document conveyance path and is rotatably attached to the casing about a rotation axis provided on the casing so that the document conveyance path can be opened to the outside. A member,
A pressing member that is held by the housing at a position adjacent to the guide member and presses the document in the fixed reading method,
The pressing member is held so as to be movable up and down with respect to the casing, and one end portion of the pressing member is connected to the guide member at a position spaced from the rotating shaft, thereby rotating the guide member. An automatic document feeder, wherein the pressing member is configured to move up and down relative to the casing in a direction orthogonal to the axial direction of the rotation shaft.   The automatic document feeder according to claim 1, wherein the pressing member includes a support plate and a pressed white plate attached to a lower surface of the support plate.   The automatic document feeder according to claim 1, wherein the pressing member includes a support plate and a pressed white sheet attached to a lower surface of the support plate.   4. An automatic document feeder, wherein the pressed white plate or the pressed white sheet is detachably attached to the support plate according to claim 2 or 3 by a hook-and-loop fastener.   2. The automatic document feeder according to claim 1, wherein the pressing member has a two-layer integrated structure of an upper support plate layer and a lower pressed white layer.   One end portion of the pressing member is connected to the guide member by a first connecting portion, and the other end portion is connected to the housing by a second connecting portion, and the first connecting portion or the second connecting portion. The automatic document feeder according to claim 1, wherein the automatic document feeder includes a long hole and a slide pin that is slidable in the longitudinal direction in the long hole.   The automatic document feeder according to claim 6, wherein an elastically deformable convex portion that constrains a slide position of the slide pin is formed at a longitudinal intermediate portion of the long hole.   The automatic document feeder according to any one of claims 1 to 7, further comprising a buffer member that attenuates a rotational speed of the guide member.   An image forming apparatus or an image reading apparatus comprising the automatic document feeder according to claim 1.

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