JP3378123B2 - Document separation and transport device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a document separating / conveying apparatus, and more particularly, in an automatic document feeder used for automatically feeding a document in an image forming apparatus or the like, a plurality of documents are set. The present invention relates to a document separating / conveying device used for surely separating and conveying one sheet at a time.

[0002]

2. Description of the Related Art An image forming apparatus such as a copying machine, a facsimile machine, a printer, a printing machine, a scanner or the like is provided with a reading means for reading an original, and a plurality of sheets are set in a stacked state on an original table. An automatic document feeder (ADF) is used as a means for automatically feeding and conveying the formed originals one by one to a reading position. 2. Description of the Related Art Separation and conveyance devices have been conventionally used in order to reliably separate and feed sheets of a document bundle one by one.

Japanese Unexamined Patent Publication No. 6-127721 discloses a separation pad type automatic document separating and conveying apparatus.
FIG. 6 is an explanatory view of the main configuration of this automatic document separating and conveying apparatus. In this apparatus, a separation pad 101 is brought into pressure contact with a separation roller 100, and an upstream side of a pressure contact point between the separation roller and the separation pad. By providing the regulating member 102 on the back side of the pad, the separation pad is prevented from rising when a large number of documents D are inserted. In this prior art, the structure is such that a conveying force is applied to the original document only when the original document D is correctly inserted into the pressing contact portion between the separating pad 101 and the separating roller 100, and the original document is auxiliary conveyed to this pressing portion. There is no means to make it. A separating roller projects upward from the table T on which the document is set, and the pressure contact portion is located a predetermined distance above the table top surface, while the leading edge of the document is guided to the pressure contact portion. There is no guide member. In addition, since the shape of the wedge-shaped space formed between the separation roller and the separation pad is usually constant, the separation pad is used to track the difference in the thickness of the original, the number of sheets to be loaded, the strength of the waist, the paper quality, etc. The pressure state could not be changed.

For this reason, the ability to pick up the original becomes unstable depending on the conditions on the side of the original, and if the conveyance path resistance increases due to static electricity or the like generated by friction between the table portion and the original, the pickup is performed. There was a problem that the printed document did not reach the pressure contact part. Also, when a small number of originals or thin originals are set on the table T, the leading edge of the originals stops while abutting against the roller peripheral surface below the pressure contact portion. Even if the document is pushed into, the document will buckle and the leading edge will not reach the proper position, making it impossible to convey. Further, when a large number of original documents D are set on the table T, there is no means for pushing the original document bundle toward the roller side, so that the upper original document has a space between its tip and the separation pad 101. Due to the resistance, there is a problem that the pressure contact part cannot be entered even after the previous page (the page immediately below) is conveyed, or the lower document hits the roller when the upper document hits the separation pad during setting. There was a problem that the tip could not be inserted into the press contact part.

The separating pad 101 is usually made of a material having a high coefficient of friction such as rubber. However, when the document on the table T is exhausted after the conveyance of the last page, the separating roller 100 is separated. Since it directly contacts 101, the separation roller pulls the separation pad.
In addition, a one-way clutch or the like is inserted into the shaft of the separation roller to make the separation roller a driven roller, and when the document is conveyed by the roller located on the downstream side of the separation roller, the separation is performed via the document. It is possible to rotate the rollers together, but in this case as well, there is no change in the situation in which the separation pad is pulled by the document. When the separation pad is pulled, the wedge-shaped space formed between the separation pad and the separation roller becomes narrower, so the shapes of the leading ends of a plurality of originals that enter the separation space also become steep,
As a result, the above-mentioned problems are promoted.

[0006]

As described above, in the conventional separating / conveying apparatus, when the resistance of the conveying path increases due to static electricity or the like, the picked-up original does not reach the pressure contact portion, and a small number of originals or When a thin paper document is set on the table T, even if it is forcibly pushed in, the document will buckle and the leading edge will not reach the normal position, and the document cannot be conveyed.
Further, when a large number of originals D are set on the table T, there is no means for pushing the original bundle toward the rollers, so that the upper original is pressed even after the previous page is conveyed. However, there are problems such as being unable to enter the part, and when the upper document hits the separation pad during setting, the lower document hits the roller and the tip cannot enter the pressure contact part. In addition, the separation roller or the original document pulls the separation pad, and the wedge-shaped space at the pressure contact portion between the separation roller and the separation pad becomes narrow, which promotes the above-mentioned problems. The present invention solves such a problem, and the set original can be reliably pre-fed to the separated portion regardless of the number of loaded originals, paper quality, and paper thickness, and the original to be used. To provide a document separating / conveying device capable of easily changing the setting of the pre-feed leaf spring to an optimum state according to the property of the device and confirming the setting state from the outside of the apparatus body. It is an object.

[0007]

In order to achieve the above object, the invention according to claim 1 forms an image in which the originals stacked on the original table are separated and conveyed one by one from the lowermost part and sequentially read the images. In an automatic document feeder including a separation pad type separation unit used in an apparatus or the like, the separation unit includes a feeder for taking out a document and a separation pad for pressing the feed roller to separate the document. , A pad holder whose base end is rotatably supported in the vertical direction by a pressure plate and which holds a separation pad, and a pressure plate which holds the base end of the pad holder and the separation pad under pressure between the pressure plate. bottom which is supported on the arms in contact with the feed roller outer peripheral surface at the tip extending from the bottom at a predetermined inclination angle, parallel
And a pre-feed leaf spring having a screw support member extending from the bottom and the screw support member is pushed in to move the pre-feed leaf spring.
Document feed from the feed leaf spring to the feed roller
Can be moved parallel to the direction and can be fixed at multiple predetermined positions
Equipped with an adjustment screw to
Resin or spring metal plate is used as the material.
At the same time, the pre-feed leaf spring is made into a beam shape and fixed in place.
At the position, the tips of the arms of the pre-feed leaf spring are
Contact the feed roller with a fixed pressure contact force
It is characterized by being configured . The invention according to claim 2 is characterized in that the pre-fed leaf spring can be fixed / released and moved without removing the exterior portion of the device body. The invention according to claim 3 is characterized in that the set position of the pre-feed leaf spring can be confirmed by making a part of the pre-feed leaf spring visible from outside the device.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a diagram showing a separation unit, a conveyance unit, and a reading unit of an image forming apparatus to which the present invention is applied, FIG. 2 is a cross-sectional view showing a configuration of a main part of the separation unit, and FIG. 3 is an exploded perspective view of the separation unit. is there. The document transport unit 1 includes a separation unit 2 and a transport unit 3. The separation unit 2 is composed of a feeder roller 4 driven by a drive source such as a motor (not shown) and a separation pad 5 that is in pressure contact with the outer peripheral surface of the feed roller 4, and has a friction coefficient between the feed roller and the original. By increasing the coefficient of friction between the separation pad 5 and the original in the former case (feeder roller 4), it is possible to feed the originals one by one from the bottom. .

A document separated by the separation unit 2 and sequentially conveyed is conveyed by the conveyance roller pair 6 to the reading unit 7 at a predetermined speed, and passes through the reading position.
Upon receiving illumination from 0, the reflected light of the original is received by the photoelectric conversion element 13 via the mirror 11 and the lens 10. Also, after the original has passed through the reading section,
The sheet is conveyed to the sheet discharge tray-15 and discharged. These rollers 6 and 14 are driven by a drive system such as a motor and gears (not shown). In addition, the document position is detected by the field
This is performed by a first sensor 21 that detects the presence of a document on the document table 20 on the front side of the printer 4, and a second sensor 22 that detects that the document has reached the reading position. A control unit such as a microcomputer (not shown) drives the rollers 4, 6, 14 according to the detection information from these sensors and controls the reading optical system constituting the reading unit 7 at a predetermined timing. Reference numeral 24 is a pressure plate located above the reading position.

FIG. 2 is an enlarged cross-sectional view showing the specific construction of the separating portion, and FIG. 3 is an exploded perspective view showing the schematic construction of the separating pad 5, the pad holder 25, the holding plate 26, and the pre-feed leaf spring 27 on the lower side. The state seen from. As shown in FIG.
In the support recess 30 of the pressure plate 24, the pad holder 25, the separation pad 5, the pressing plate 26, and the pre-feed leaf spring (cantilevered beam shape) 27 are assembled in this order, and these member groups constitute one separating portion. is doing.

The pad holder 25 is a substantially plate-like member made of an elastic material such as resin, and the support shaft 3 is provided at both corners of its base end.
5, the support shafts 35 are fitted into U-shaped groove portions 36 provided in the support recesses 30 of the pressure plate 24 so that they can be freely swingably attached to the pressure plate 24. An end portion (a free end portion) 35a of the pad holder 25 opposite to the support shaft 35 is inserted into an opening portion 37 of the pressure plate 24, and the free end portion 35a does not come into contact with the pressure plate 24 in a document conveyance state. For maintenance such as processing and roller cleaning, pad holder 25
2 is rotated counterclockwise about the support shaft 35 in FIG. 2, so that the free end portion 35a abuts against the pressure plate 24, and this position becomes the bottom dead center of the pad holder 25. Further, a protrusion 38 is provided at a central position between the two support shafts 35 of the pad holder 25, and a tension coil spring 40 is applied between the protrusion 38 and the locking portion 39 provided on the pressure plate 24. , The pad holder 25 is constantly urged in the counterclockwise direction about the support shaft 35 to bring the separation pad 5 into pressure contact with the feeder roller 4. Further, two holes 41 are penetratingly formed at appropriate places near the base end portion of the pad holder 25.

The separation pad 5 has a hole 41 in the pad holder 25.
As shown in FIG. 3, the two protrusions 26a provided on the holding plate 26 made of resin or the like are inserted into the hole 45 of the pad 5 and the hole 41 of the pad holder 25, respectively. As a result, these three members 26, 5 and 25 are fixed. The fixing method is a method of forming the pressing plate 26 or the pad holder 25 using an elastic member such as resin and elastically crimping the protrusion 26a and the holes 41 and 45, or a method using a screw or an adhesive. It may be. The holding plate 26 is formed of a material having high slidability (low frictional resistance) such as resin to reduce the contact resistance between the holding plate 26 and the original.

A flat portion 50 is provided on the recess 30 of the pressure plate 24, that is, on both sides of the pad holder mounting position. The seat portion 51 of the pre-leaf leaf spring 27 is seated on the flat portion 50 and at the same time, Seat portion 51 of leaf spring 27
And the U-shaped groove 36 between the support shaft 35 of the pad holder 25.
Rotatably supported. The pre-feed leaf spring 27 is made of an elastic material such as metal or resin as a spring material, and is used as the separation pad 5
Has two arm portions 52 at positions corresponding to the outer sides of both side edges, and the tip end portion of each arm portion 52 is pressed against the feeder roller 4. The arm portion 52 is integrated with the seat portion 51 in a state of being bent at a predetermined angle.

Tip portions 51a of the two seat portions (bottom portions) 51
The rear end portion 51b and the rear end portion 51b are inserted into a slit 53 provided on the front end side of the recess 30 of the pressure plate 24 and a slit 54 provided on the rear end side of the pressure plate 24, respectively, whereby the pre-feed leaf spring 27 is positioned and fixed in the recess 30. Will be certain. At this time, the pre-feed leaf spring 27 seated in the recess 30 is
It is possible to move back and forth only in the front-back direction indicated by arrow A within 0.

FIGS. 4 and 5 are a sectional view and a perspective view of an essential part of a separating portion according to a second embodiment of the present invention. This embodiment includes an adjusting screw 60, and this adjusting screw is used. The configuration is characterized in that the position of the pre-feed leaf spring 27 is finely adjusted in the front-rear direction (direction A). Separation pad 5 and pad holder 2 which are each member constituting the separation portion of this embodiment.
5, the constitutions of the pressing plate 26 and the pressure plate 24 are the same as those of the above-mentioned embodiment, but the rear end edge central portion of the continuous portion (bottom portion) 61 that continuously connects the two seat portions 51 of the pre-feed leaf spring 27. Is provided with a screw support member 62 bent at 90 degrees, and a U-shaped groove 6 for screw support is provided on an edge of the screw support member 62.
2a is formed, and an indicator portion 63 bent at 90 degrees in the opposite direction to the screw support member 62 is provided at the center of the front edge of the continuous portion 61.
The difference is that. The front end portion 51a and the rear end portion 51b of the pre-feed leaf spring 27 are respectively inserted and locked in the slits 53 and 54 of the pressure plate 24 as in the case of the above embodiment. The seat portion 51 is the flat portion 50 of the recess 30 as described above.
It is supported so that it can move back and forth in the direction A while seated at.

A groove portion on the outer periphery of the engaging member 65 is fitted in the U-shaped groove 62a so as to be relatively rotatable, and a tip portion of the adjusting screw 60 is fixed to the engaging member 65. As shown in FIG. 4A, the adjusting screw 60 is supported by being screwed into a screw hole 66 provided at the rear end of the pressure plate 24, and the engaging member 65 is moved forward and backward by rotating the adjusting screw 60 in the forward and reverse directions. As a result of advancing and retracting in the direction A, the pre-feed leaf spring 27 can also integrally advance and retract in the front-rear direction A.

The indicator 63 is a visual hole 71 provided in the housing 70.
The front end portion is located at the position, and the visual hole 71 is moved in the front-rear direction according to the forward / backward movement of the pre-feed leaf spring 27. At this time, as shown in FIG.
By forming an indication such as thick paper, standard, thin paper, etc. on the edge of the document, the feeder can be selected according to the characteristics of the original to be used.
It is possible to move the contact point of the arm portion 52 of the pre-feed leaf spring 27 with respect to the roller 4 in the front-rear direction (original feeding direction), and it is possible to change the pre-feed start position of the set original.

In the above description, the adjusting screw 60 is used to change the position of the pre-feed leaf spring 27 in the front-rear direction. However, the pressure plate 24 and the pre-feed leaf spring 27 have holes and half punches, respectively, or It is also possible to provide a plurality of combinations of concavo-convex fitting such as slits and bending, and use the elasticity of the pre-filled leaf spring 27 to fix it at an arbitrary predetermined position. Further, when instructing the position of the pre-feed leaf spring 27, it is also possible to use another portion of the pre-feed leaf spring 27 or mark the adjustment screw side.

The function of the pre-feed leaf spring 27 is that the arm 5
The tip of 2 is the outer peripheral surface of the feeder 4
The document to be fed is preliminarily urged toward the pressure contact portion by being pressed into contact with the upstream position of the pressure contact portion between the drawer 4 and the pad 5, and this pre-feed function allows the document to be fed. It is possible to reliably press the tip portion into the press contact portion. Therefore, even if the feeder roller 4 projects above the guide plate (original table) 20, it is possible to prevent the upper original from being unable to enter the pressure contact portion. Also, as shown in FIG. 4 (b), in the case of thick paper, the tip of the arm 52 is brought closer to the pressure contact portion, and the tip of the arm portion is moved away from the pressure contact portion as the document becomes thinner and the waist becomes weaker. By adjusting the position of the pre-feed leaf spring 27 in the front-rear direction, it is possible to realize the optimum separation and feeding state according to the property of the original.

Further, by using the pre-feed leaf spring 27, each document can be surely brought into the pressure contact portion even when the conveyance resistance increases due to static electricity. Even if a small number of originals or thin originals are set, the preliminary original push-in will be performed sufficiently, so it will stop when the leading edge of the original hits the roller, or it will be impossible due to lack of rigidity. It is also possible to prevent the tip from buckling when pushed into.

When a large number of originals are set on the table, the upper (subsequent) original enters the pressure contact portion after the previous page is conveyed by the resistance between the leading end of the original and the separation pad 5. However, there is a problem in that the lower original cannot hit the roller and enter the pressure contact portion when the upper original hits the separation pad during setting. However, in the present invention, the arm portion of the pre-feed leaf spring 27 is present. Since the front end of the pad 5 comes into contact with the original before the separation pad 5 to regulate the movement thereof, the frictional resistance of the pad 5 does not adversely affect the original. That is, the state where the upper original cannot enter the pressure contact portion when a large number of sheets are set is caused by the resistance of the pad 5, but in the present invention, the pre-feed leaf spring comes into contact with the original in advance. Since the arm portion has a small frictional resistance, the upper document can be smoothly guided to the pressure contact portion. In addition, the upper document hits the separation pad, so that the lower document cannot enter the pressure contact portion.
Prevents the separation pad 5 from coming into contact with the original document in advance, which is solved.

Further, in this embodiment, even when the feed roller and the separation pad come into contact with each other when the document is completely fed and the separation pad is pulled and the wedge-shaped space of the press contact portion is narrowed, Since the space of the wedge-shaped space formed between the feed roller and the arm that is in contact with the feed roller on the upstream side does not change, the document is fed normally without being affected by the deformation of the separation pad. You can Conversely, by changing the longitudinal position of the pre-feed leaf spring to change the pressure contact between the arm and the feed roller, a wedge-shaped space formed between the arm and the feed roller (the angle of inclination of the arm) ) Can be changed, it is possible to secure an appropriate paper feeding state according to the difference in the characteristics of the original.

[0023]

As described above, according to the present invention, the set originals can be surely pre-fed to the separation portion regardless of the number of originals to be loaded, the paper quality and the paper thickness, and the characteristics of the originals to be used can be improved. It is possible to provide a document separating / conveying device capable of easily changing the setting of the pre-feed leaf spring to an optimum state according to the situation and confirming the setting state from the outside of the apparatus body. . That is, in the document feeder according to the first aspect, since the pre-feed leaf spring 27 is movable with respect to the feeder roller 4, the contact point between the pre-feed leaf spring 27 and the separating roller 4 is set. It is possible to move the (pressing part) in the document conveying direction and change the pre-feed start position of the set document according to the properties of the document (paper thickness, waist strength, slippage, etc.). With
In addition, a cantilever-shaped plug that contacts the feeder roller 4 at the arm
Set the position of the leaf spring 27 to the front of the separating roller 4.
Although it is translated in the rearward direction,
Adjust the position where the arm is in contact with the outer surface of the feeder
By this, the arm of the leaf spring 27 and the feeder
The pressure contact force can be easily set, and the pre-fed leaf spring 27
Since the shape of the document can be simplified, the manuscript of paper quality etc.
It is possible to meet the conditions.

[0024]

In the document feeder according to the second aspect of the present invention, the pre-fed leaf spring 27 can be fixed / released and moved without removing the exterior part of the device body.
It is possible to display the optimum position of the leaf spring 27 according to the paper quality and the like at the time of adjustment using the adjustment screw or the like, and it is possible for the operator to easily change to the optimum condition. Further, since the pre-feed leaf spring can be easily attached to and detached from the pressure plate and exchanged, it is possible to flexibly change the pre-feed leaf spring according to the type of the fed document and the like to exert the optimum pre-feed function.

In the document feeder of claim 3 , since the fixed setting position of the pre-feed leaf spring 27 can be confirmed from the outside of the device, the setting is not mistaken during use, and the fixing position is directly indicated. Therefore, the above-mentioned effects can be obtained at low cost.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a separation unit, a conveyance unit, and a reading unit of an image forming apparatus to which the present invention is applied.

FIG. 2 is a cross-sectional view showing a configuration of a main part of a separation section.

FIG. 3 is an exploded perspective view of a separation unit.

4 (a) and 4 (b) are a fragmentary sectional view and a partially enlarged view of another embodiment of the present invention.

5 is a perspective view of a pre-feed leaf spring used in the embodiment of FIG.

FIG. 6 is an explanatory diagram of a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 original conveying section, 2 separating section, 3 conveying section, 4 feed roller, 5 separating pad, 6 conveying roller pair, 7 reading section, 10 light source, 11 mirror, 13 photoelectric conversion element, 25 pad holder, 26 holding plate, 27 Pre-feed leaf spring, 30 indicated recess, 35 support shaft, 36
U-shaped groove part, 37 opening part, 39 locking part, 40 tension coil spring, 41, 45 hole, 50 plane part, 51 seat part (bottom part), 52 arm part, 53, 54
Slit, 60 adjusting screw, 61 continuous part (bottom part), 6
2 screw support member, 63 indicator,

Claims (3)

(57) [Claims] 1. An automatic document feeder including a separating pad type separating section used in an image forming apparatus or the like for separating and conveying the originals stacked on an original table one by one from the bottom and sequentially reading the images. In the apparatus, the separation section includes a feed roller for taking out a document, a separation pad for pressing the feed roller to separate the document,
A pad holder having a base end rotatably supported in a vertical direction by a pressure plate and holding a separation pad, and a pressure plate for holding the base end of the pad holder and the separation pad between the pressure plate and the pad holder. bottom supported, the arm portion in contact with the feed roller outer peripheral surface at the tip extending from the bottom at a predetermined inclination angle, and the pre-feed plate spring and a screw support member extending from the bottom, the screw support member Push in
Only the above pre-feed leaf spring to the above-mentioned feed roller
Can be moved in parallel in the document transport direction and can be moved to multiple predetermined positions.
There are an adjustment screw which can be fixed, as the material of the pre-feed plate spring, a resin, or spring
Pre-fed leaf springs with a metal plate
Is a beam shape, and the pre-feed plate is at a fixed position
The tips of the arms of the spring each have a set pressure contact force
A document separating / conveying device, which is configured so as to come into contact with a roller . 2. Fixing / release of the pre-feed leaf spring,
You can move without removing the exterior part of the device body
2. The document separating / conveying apparatus according to claim 1, wherein
apparatus. 3. A part of the pre-fed leaf spring is a device.
By making it visible from the outside
The contract featured that the set position of the leaf spring can be confirmed.
The document separating / conveying apparatus according to claim 1 or 2.