JP3531095B2 - Automatic document feeder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder installed in a document processing machine such as an electrostatic copying machine, a facsimile or an image reader.

[0002]

2. Description of the Related Art In recent years, a copying machine has come to use an automatic document feeder for automatically feeding a plurality of documents to a document setting position on the upper surface of a transparent plate in accordance with the speeding up and automation of the copying process. There is. In addition, an automatic document feeder for automatically feeding a plurality of documents sequentially to a document processor such as a facsimile or an image reader is widely put into practical use. This type of automatic document feeder includes a document table on which a document is placed, a guide plate arranged on the downstream side of the document table, and an opening formed on the guide plate below the guide plate. A part of the outer peripheral part of the document feeds upward and acts on the lower surface of the lowest document placed on the document table to feed the document, and a forward feed roller is provided downstream of the forward feed roller in the transport direction. It is provided with a paper feed roller and a document separating mechanism arranged to face the paper feed roller. Further, between the front feed roller and the paper feed roller, there is provided a pre-sorting means for limiting the number of originals entering between the paper feed roller and the original separation mechanism to a small number (1 to 3). ing.

The front loosening means is a front loosening support plate disposed in the axial direction of the forward feed roller, and an elastic member attached to the lower end of the front loosening support plate and facing the paper feed roller. And a front separating plate made of a sheet member having The plurality of documents fed by the front feed roller are conveyed to the document separation mechanism side so that a small number (1 to 3) of them pass through the gap between the front separating section and the paper feed roller.

[0004]

In the automatic document feeder described above, the quality of the original document (especially the quality of the paper having a high friction coefficient).
Depending on the situation, a large number of originals may try to pass through the gap between the paper feed roller and the front separating plate at the same time. in this case,
The front separating plate elastically deforms with the contact portion with the lower edge of the front separating support plate as a fulcrum, but if a large number of originals are sandwiched between the paper feeding roller and the front separating plate, the elastic limit of the front separating plate is increased. There is a problem that it permanently deforms beyond the range and the function as the front separating plate becomes defective.

The present invention has been made on the basis of the above facts, and its main technical problem is to provide an automatic document feeder including a front separating means which prevents the front separating plate from being permanently deformed. is there.

[0006]

In order to achieve the above main technical problems, according to the present invention, a document table on which a document is placed, and a guide plate arranged on the downstream side of the document table, Before sending out the original by acting on the lower surface of the lowest original placed on the original table, with a part of the outer periphery protruding upward from the opening formed in the lower side of the guide plate A feed roller, a paper feed roller arranged on the downstream side of the forward feed roller in the conveying direction, a document separating mechanism arranged to face the paper feeding roller, and an upstream side of the document separating mechanism in the conveying direction. In an automatic document feeder including a pre-sorting unit arranged to face the sheet feeding roller, the pre-sorting unit includes a pre-sorting support plate disposed in the axial direction of the sheet feeding roller. It is attached to the lower end of the front separation support plate and is arranged so as to face the paper feed roller. And a front separating plate made of a sheet member having elastic properties, the front separating plate is attached to the front separating support plate via an elastic member, and when the front separating plate is deformed, the front member of the elastic member is deformed. There is provided an automatic document feeder in which a lower end edge on the side of a separating plate is elastically deformed into an arc shape.

The paper feeding roller is provided with a plurality of roller portions provided at predetermined intervals in the axial direction, and the front separating plate is a convex shape positioned between the roller portions of the paper feeding roller. It has a separating section.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of an automatic document feeder constructed according to the present invention will be described in detail below with reference to the accompanying drawings.

1 and 2 show an upper end portion of an electrostatic copying machine 2 and an automatic document feeder 4 mounted on the upper end portion. The electrostatic copying machine 2 has a housing 6, and a transparent plate 8 (FIG. 2), which may be a glass plate, is arranged on the upper surface of the housing 6. On one side of the transparent plate 8 (on the left side in FIG. 2), a document regulating member 1 that defines a document setting reference position G
0 is disposed, and the stationary mounting member 12 is disposed on the other side (right side in FIG. 2). An automatic document feeder 4 constructed in accordance with the present invention comprises a housing 6 of an electrostatic copier 2.
Is mounted on the upper surface of the transparent plate 8 so as to be rotatable between a closed position shown by a solid line in FIG. 1 and an open position shown by a chain double-dashed line about a turning axis extending along the rear side edge of the transparent plate 8. Electrostatic copying machine 2
When a document is manually placed on the transparent plate 8, the automatic document feeder 4 is opened to expose the transparent plate 8 and the document is placed at a desired position on the transparent plate 8. The document feeder 4 is closed to cover the transparent plate 8 and the document placed on the transparent plate 8. When placing the original on the transparent plate 8, the original is required by bringing one edge of the original into contact with the leading edge of the original regulating member 10 and positioning the trailing edge of the original at the original setting reference position G. Can be positioned in any position. When a document is automatically loaded onto the transparent plate 8 using the automatic document feeder 4 and is automatically discharged from the transparent plate 8, the automatic document feeder 4 is positioned at the closed position.

Continuing the description with reference to FIG. 1, the illustrated automatic document feeder 4 includes a front cover 14 and a rear cover which are arranged at intervals in the front-rear direction (direction perpendicular to the paper surface in FIG. 2). Includes 16. The front cover 14 and the rear cover 16 can be formed of an appropriate synthetic resin. A rear support substrate (not shown) is arranged in the rear cover 16, and such a rear support substrate is provided with a mounting mechanism (not shown) which may have a known form. And is mounted on the upper surface of the housing 6 of the electrostatic copying machine 2 so as to be freely rotatable. Various components of the automatic document feeder 4 are directly or indirectly supported on the rear support substrate. A document placing unit 18 and a document discharge tray 20 are provided between the front cover 14 and the rear cover 16. The document placing means 18 includes a document table 22 extending upwardly from the left end to the right rear end in FIG. 2, and an auxiliary table rotatably mounted at the rear end of the document table 22. It consists of 24. A pair of width regulating members 26 is attached to the document table 22 so as to be movable in the width direction. Such a pair of width regulating members 26 are connected to each other below the document table 22 via a rack and a pinion mechanism (not shown) which are known per se, and they interlock with each other to approach each other. To move in the direction away from each other.
The document discharge tray 20 is arranged below the document placing means 18, and has a document placing surface 201 formed in a mountain shape when viewed from the front-rear direction (direction perpendicular to the paper surface in FIG. 2). A left end cover 28 is provided between the left ends of the front cover 14 and the rear cover 16, and a right end cover 29 is provided between the right ends thereof.

Continuing the description with reference to FIGS. 1 and 2, a forward feeding means 30 is arranged on the downstream side of the original table 22 in the conveying direction. This forward feeding means 30
A guide plate 32 is provided which extends downstream of the document table 22 in the transport direction. An opening is formed on the upstream side of the guide plate 32, and a forward feed roller 34 that constitutes the forward feed means 30 is disposed below the opening. The forward feed roller 34 is made of an elastic material having a large friction coefficient such as urethane rubber, and is arranged such that a part of the outer peripheral surface thereof projects slightly upward from an opening formed in the guide plate 32. The rotation shaft (not shown) of the forward feed roller 34 is
It is transmission-coupled to an electric motor 35 that is a drive source via a power transmission mechanism (not shown).

Above the forward feed roller 34, a forward feed pressurizing mechanism 36 constituting the forward feed means 30 is arranged. The forward feed pressure mechanism 36 includes a rotary shaft 36 disposed above the forward feed roller 34 in parallel with the forward feed roller 34.
2 and a pressure plate 364, the upper end of which is fixed to the rotating shaft 362 and the lower end of which is placed on the document table 22 and which acts on the document (P) inserted on the guide plate 32. . In the illustrated embodiment, the pressure plate 364 is formed of an elastic thin plate made of a stainless steel plate, the upper end of which is fixed to the rotating shaft 362 by a fixing means such as a screw, and the lower end of which is the front portion. Feeding roller 34
In the upper position of the document table, it is arranged such that it is positioned at an operating position that acts on the upper surface of the uppermost document placed on the document table 22 to press the document and a non-operating position that is separated from the document. The rotary shaft 362 that constitutes the forward feed pressurizing mechanism 36 is rotatably supported by side plates provided at the front and rear ends of the support substrate 38 disposed above the forward feed roller 34. The rotating shaft 362 is connected to a solenoid (not shown) via a link mechanism, and is rotated in a predetermined direction when the solenoid is energized, and is rotated in a predetermined direction when the solenoid is deenergized. It can be rotated in the opposite direction. Therefore, the pressure plate 3 attached to the rotating shaft 362
Reference numeral 64 denotes a rotating shaft 362 which is energized by a solenoid (not shown).
Is rotated in a predetermined direction, the original inserted in the guide plate 32 is pressed, the solenoid is deenergized, and the rotating shaft 362 is rotated.
When is rotated in the direction opposite to the predetermined direction, it is separated from the document.

A paper feed roller 40 is arranged downstream of the forward feed means 30. This paper feed roller 40 is shown in FIG.
As shown in FIG. 4, a rotary shaft 42, a tubular portion 44 attached to the rotary shaft 42, and a plurality of (four in the illustrated embodiment) roller portions 4 mounted on the outer peripheral surface of the tubular portion 44.
It consists of 6. The rotary shaft 42 is transmission-coupled to the electric motor 35, which is a drive source, via a power transmission mechanism (not shown). The tubular portion 44 is formed of an appropriate synthetic resin into a cylindrical shape, and is integrally attached to the rotary shaft 42. The plurality of rollers 46 are made of a material having a large friction coefficient such as urethane rubber, and are mounted on the outer peripheral surface 441 of the tubular portion 44 at predetermined intervals in the axial direction. The plurality of rollers 46 are arranged such that a part of the outer peripheral surface thereof projects slightly upward from the opening formed in the guide plate 32.

A document separating mechanism 50 is arranged above the paper feeding roller 40. The document separating mechanism 50 includes a separating roller 51 in the illustrated embodiment. The separation roller 52 includes a fixed shaft 52 and a tubular portion 53 formed of an appropriate synthetic resin and rotatably disposed on the fixed shaft 52.
And a surface layer portion 54 formed of an elastic material having a large friction coefficient such as urethane rubber and attached to the outer peripheral surface of the cylindrical portion 53.
And a torque limiter mechanism 55 disposed between the fixed shaft 52 and the tubular portion 53, and the surface layer portion 54 is disposed in contact with the outer peripheral surface of the roller portion 46 of the paper feed roller 40. ing. The torque limiter mechanism 55 includes the tubular portion 53.
When a driving torque larger than a predetermined value is applied to the fixed shaft 52, the spring clutch mechanism fixes the tubular portion 53 to the fixed shaft 52.
The separation roller 51 equipped with this torque limiter mechanism 55 is
The present invention does not constitute a novel feature of the automatic document feeder according to the present invention, and the configuration of itself may be a well-known form. Therefore, for details of the configuration,
Description is omitted in this specification. It should be noted that in the illustrated embodiment, the separating roller 52 is used as the document separating mechanism 50.
However, as the document separating mechanism 50, a separating belt mechanism or another separating mechanism can be used.

A pre-sorting means 60 is disposed on the upstream side of the document separating mechanism 50 in the conveying direction so as to face the paper feeding roller 40. The pre-separation unit 60 is provided in the axial direction of the paper feed roller 40 and has a top end portion attached to the support substrate 38 by a screw 62, and an upper end portion at the lower end portion of the front separation support plate 64. The front separating plate 66 is attached. The front separating plate 66 will be described with reference to FIGS. 3 and 4. The front separating plate 66 is formed of a sheet member having elasticity. In the illustrated embodiment, the front separating plate 66 is formed of a polyethylene terephthalate (PET) resin sheet member having a thickness of 0.125 mm, and the upper end portion thereof is formed of a fixing member such as an adhesive or a double-sided adhesive tape. It is attached to the support plate 64. At the lower end of the front separating plate 66, a plurality of convex separating parts 661 are provided at corresponding positions between the rollers 46 of the paper feeding roller 40. The separating section 661 of the front separating plate 66 is formed in a trapezoidal shape in the embodiment shown in FIG.
The roller 46 is disposed so as to project inward from the outer peripheral surface 461. In addition, in the illustrated embodiment, the separation unit 66 is provided from the lower end of the front separation support plate 64 in the front separation plate 66.
The protrusion amount (H1) to the base portion of 1 is 0.5 mm, and the separation portion 6
The amount of protrusion (H1) from the base to the tip of 61 is 0.9 mm
Is set to.

Next, the mounting structure of the lower end portion of the front separating plate 64 and the front separating plate 66 will be described with reference to the embodiments shown in FIGS. 4 to 7. In the first embodiment shown in FIG. 4, the lower edge of the front separation support plate 64 on the surface side on which the front separation plate 66 is mounted is formed into an arc surface 641. Therefore, when a large number of originals simultaneously pass between the paper feed roller 40 and the front separating plate 66 and the front separating plate 66 is largely deformed, the front separating plate 66 and the lower edge of the front separating plate 64 are separated. The contact position is displaced along the arc surface 641. That is, when the front separating plate 66 is deformed, the deforming fulcrum is the arc surface 6
It is displaced along the line 41 from the upper side to the lower left side in FIG. Therefore, since the front separating plate 66 does not deform at a specific fulcrum, it does not permanently deform.

In the second embodiment shown in FIG. 5, the lower end portion of the front separation support plate 64 is bent at a substantially right angle to the side opposite to the surface on which the front separation plate 66 is mounted, so that the front separation support plate 64 is separated. The circular arc surface 6 is provided on the lower edge of the surface on which the plate 66 is mounted.
41 is formed. Therefore, when a large number of originals simultaneously pass between the paper feed roller 40 and the front separating plate 66 and the front separating plate 66 is largely deformed, the front separating plate 66 and the front separating plate 66 are deformed similarly to the embodiment shown in FIG. Since the contact position with the lower end edge of the support plate 64 is displaced along the circular arc surface 641, permanent deformation of the front separating plate 66 is prevented.

In the third embodiment shown in FIG. 6, when the front separating plate 66 is adhered to the front separating support plate 64 with the double-sided adhesive tape 67, the lower end of the double-sided adhesive tape 67 is separated from the lower end of the front separating support plate 64. It is located 1-2 mm above.
Therefore, when a large number of originals simultaneously pass between the sheet feeding roller 40 and the front separating plate 66 and the front separating plate 66 is largely deformed, the front separating plate 66 first uses the lower end edge of the double-sided adhesive tape 67 as a fulcrum. When the deformation reaches a predetermined amount, the front separation support plate 64 comes into contact with the lower edge of the front separation support plate 64,
It deforms with the lower edge of 4 as a fulcrum. That is, the front separating plate 66
When is deformed, the fulcrum of deformation is double-sided adhesive tape 67.
From the lower end edge of the front handling support plate 64 to the lower end edge. Therefore, since the front separating plate 66 does not deform at a specific fulcrum, it does not permanently deform.

In the fourth embodiment shown in FIG. 7, an elastic member 68 such as rubber is interposed between the front separating support plate 64 and the front separating plate 66. Therefore, when a large number of documents simultaneously pass between the paper feed roller 40 and the front separating plate 66 and the front separating plate 66 is largely deformed, the lower end edge of the elastic member 68 on the front separating plate 66 side is elastically deformed. It becomes an arc shape. Therefore, since the front separating plate 66 elastically deforms along the arc of the elastically deformed elastic member 68, it does not deform at a specific fulcrum and stress concentration does not occur, so that it does not permanently deform.

In order to prevent the permanent deformation of the front separating plate 66, the amount of protrusion of the front separating plate 66 from the lower end of the front separating support plate 64 may be increased. However, if the amount of protrusion is increased, the front separating plate 66 is increased. The so-called waist of 66 is weakened, and the separation function is deteriorated. In each of the above-described embodiments, the amount of protrusion of the front loosening plate 66 from the lower end of the front loosening support plate 64 is set to the above-described dimension, and when the front loosening plate 66 is deformed, the lower end edge portion of the front loosening support plate 64 is formed. By displacing the contact position, permanent deformation can be prevented without deteriorating the separation function.

Continuing the description with reference to FIG. 2, a conveyor belt mechanism 70 is disposed below the document placing means 18. The conveyor belt mechanism 70 includes a driving roller 71 and a driven roller 72 which are arranged at intervals in the conveying direction (left and right in FIG. 2), an endless belt 73 wound around these, a driving roller 71 and a driven roller 72. It includes a plurality of pressing rollers 74 disposed between and. The lower running portion of the endless belt 73 extends along the transparent plate 8 of the electrostatic copying machine 2, and a document transport path 75 is defined between the two.

The original transport path 75 and the paper feed roller 40
A document carry-in path 80 is formed between the and. The original carry-in path 80 is defined by an inner guide plate 801 and an outer guide plate 802. A pair of registration rollers 82 is arranged in the document carry-in path 80. The registration roller pair 82 includes a driving roller 821 and a driven roller 822. The drive roller 8 of the registration roller pair 82
21 and the drive roller 71 of the conveyor belt mechanism 70.
Are transmission-coupled to an electric motor (not shown) via an appropriate power transmission mechanism.

A document discharge means 90 is arranged on the right side of the document conveying path 75 in FIG. The document discharge means 90
Includes a document carry-out path 92, a conveyance roller pair 94 arranged in the document carry-out path 92, and a discharge roller pair 96 arranged at the discharge side end of the document carry-out path 92. The conveying roller pair 94 includes a driving roller 941 and a driven roller 942, and the discharge roller pair 96 also includes a driving roller 961 and a driven roller 962. The driving roller 941 of the conveying roller pair 94 and the driving roller 9 of the discharging roller pair 96
Reference numeral 61 is transmission-coupled to an electric motor (not shown) via an appropriate power transmission mechanism.

The automatic document feeder in the illustrated embodiment is configured as described above, and its function and effect will be described below. When performing the copying operation, the operator first places the original P to be copied on the original table 22 and inserts it in the front so that the front end portion thereof is the forward feed roller 32.
Position above. When the operator presses the copy start key, the solenoid (not shown) of the forward feed pressurizing mechanism 36 is energized to position the pressurizing plate 364 at the operating position and press the original P inserted on the guide plate 32. To do. Simultaneously with the pressing of the document P by the pressure plate 364, the electric motor 35 is driven to rotate the forward feed roller 34 and the paper feed roller 40 in the direction shown by the arrow in FIG. When the forward feed roller 34 rotates in the direction shown by the arrow in FIG. 2, it occurs at the contact portion between the outer peripheral surface of the forward feed roller 34 and the lower surface of the lowest document of the document layer inserted on the guide plate 32. The original is sent out by the frictional conveying force. At this time, although the originals on the original layer are moved in the conveying direction due to friction between each other, a small number (1 to 3) of the originals are regulated by the pre-sorting means 60 and are conveyed downstream.

Next, the operation of the pre-sorting means 60 will be described. The plurality of originals P sent out by the front feed roller 34 are regulated by the front separation plate 64 of the front separation means 60, and a small number (1 to 3) of the separation sections 661 and the paper feed roller 40 are provided. The paper passes through the rollers 46 and is conveyed to the document separating mechanism 50 side. Since the front separating plate 64 is formed of a sheet member having elasticity,
By elastically deforming in the conveyance direction when the document is separated, the document passing property is improved. At this time, when the original P has a high friction coefficient, a large number of originals may try to pass between the paper feed roller 40 and the front separating plate 64 at the same time. In this way, when a large number of originals are sandwiched between the paper feed roller 40 and the front separating plate 64 and the front separating plate 66 is largely deformed, the contact position, that is, the fulcrum of the front separating plate 64 is displaced as described above. Therefore, since the front separating plate 66 does not deform at a specific fulcrum, it does not permanently deform.

As described above, the originals restricted to a small number of sheets (1 to 3 sheets) by the action of the pre-sorting means 60, the paper feed roller 3
When passing through 2 and the separation roller 51 of the document separation mechanism 50, only the lowest document is separated and conveyed to the document carry-in path 80. Then, the front end of the document conveyed to the document carry-in path 80 is brought into contact with the nip portion of the registration roller pair 82 in the inoperative state, and the primary sheet feeding is completed.

When the primary paper feeding is completed as described above,
The pair of registration rollers 82 and the conveyor belt mechanism 70 are operated to position the trailing edge of the primarily fed document at the document setting reference position G on the transparent plate 8. Then, the exposure operation is performed. When the exposure operation ends, the conveyor belt mechanism 7
0 and the conveying roller pair 94 of the document discharge means 90 and the discharge roller pair 96 are operated, and the document which has been exposed on the transparent plate 8 passes through the document discharge path 92 and the document discharge tray 2
The document is discharged onto the original placement surface 201 of 0.

[0028]

Since the automatic document feeder according to the present invention is constructed as described above, it has the following effects.

That is, the front separating plate is attached to the front separating support plate via the elastic member, and when the front separating plate is deformed, the lower end edge of the elastic member on the side of the front separating plate is elastically deformed into an arc shape. Therefore, the front separating plate 66 is elastically deformed by the elastic member 6.
Since it elastically deforms along the arc of 8, it does not deform at a specific fulcrum, and stress concentration does not occur, so it does not permanently deform.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a preferred embodiment of an automatic document feeder constructed according to the present invention is installed in an electrostatic copying machine.

FIG. 2 is a schematic sectional view of the automatic document feeder shown in FIG.

FIG. 3 is a front view showing an embodiment of a sheet feeding roller and a pre-sorting unit which are provided in the automatic document feeder shown in FIGS. 1 and 2.

FIG. 4 is an enlarged view of an essential part showing a first embodiment of a mounting structure of a front separating support plate and a front separating plate that constitute a front separating unit equipped in the automatic document feeder shown in FIG.

5 is an enlarged view of an essential part showing a second embodiment of a mounting structure of a front separating support plate and a front separating plate that constitute a front separating unit installed in the automatic document feeder shown in FIG.

FIG. 6 is an enlarged view of an essential part showing a third embodiment of a mounting structure of a front separating support plate and a front separating plate that constitute a front separating unit installed in the automatic document feeder shown in FIG.

7 is an enlarged view of an essential part showing a fourth embodiment of a mounting structure of a front separating support plate and a front separating plate that constitute a front separating unit installed in the automatic document feeder shown in FIG.

[Explanation of symbols]

2: Electrostatic copying machine 4: Automatic document feeder 6: Electrostatic copying machine housing 8: transparent plate 10: Document control member 18: Document Placement Means 20: Document discharge tray 22: Manuscript table 30: Forwarding means 32: Information board 34: Forward feed roller 35: Electric motor 36: Pressure mechanism 362: rotating shaft of the pressurizing mechanism 364: Pressure plate of pressure mechanism 38: Support substrate 40: Paper feed roller 42: rotation axis of paper feed roller 44: Cylindrical part of paper feed roller 46: Roller part of paper feed roller 50: Document separation mechanism 51: Separation roller 60: Front handling means 64: Supporting plate for front separating means 641: Arc surface 642: arc surface 66: Front handling board 661: Separation part of front separation plate 67: Double-sided adhesive tape 68: Elastic member 70: Conveyor belt mechanism 71: Driving roller for the conveyor belt mechanism 72: Driven roller of the conveyor belt mechanism 73: Endless belt of conveyor belt mechanism 74: A pressing roller of the conveyor belt mechanism 75: Document transport path 80: Document input path 82: Pair of registration rollers 90: Document discharging means 92: Original carry-out path 94: Pair of transport rollers 96: discharge roller pair

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takatomo Fukumoto 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Kogyo Co., Ltd. (72) Inventor Shigeo Shigeo, 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Incorporated (56) Reference JP-A-9-202480 (JP, A) JP-A-3-249038 (JP, A) Actually open 62-38240 (JP, U) Actually open 1-118938 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B65H 1/00-3/68

Claims (2)

(57) [Claims] 1. A document table on which a document is placed, a guide plate arranged on the downstream side of the document table, and an outer peripheral portion from an opening formed in the guide plate below the guide plate. A front feed roller, a part of which protrudes upward and acts on the lower surface of the lowest document placed on the document table to feed the document.
A paper feed roller disposed downstream of the forward feed roller in the transport direction, a document separating mechanism disposed so as to face the paper feed roller, and the paper feed roller upstream of the document separating mechanism in the transport direction. In the automatic document feeder, the pre-sorting means comprises a pre-sorting support plate disposed in the axial direction of the paper feed roller, and the pre-sorting support. A front separating plate which is attached to the lower end of the plate and is formed of an elastic sheet member that is arranged so as to face the paper feeding roller, and the front separating plate is attached to the front separating support plate through an elastic member. are, the lower edge of the front separating plate side of the elastic member when the front separation plate is deformed ing an arcuate elastically deformed, the automatic document feeder, characterized in that. 2. The paper feed roller is provided with a plurality of roller portions provided at predetermined intervals in the axial direction, and the front separating plate is positioned between the roller portions of the paper feed roller. The automatic document feeder according to claim 1, wherein the automatic document feeder has a convex separating section.