JPH0784268B2 - Attachment structure of sheet guide member in paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sheet feeding device for a copier, an automatic document feeder, etc., in which a sheet guide member for guiding a sheet such as a copy sheet or an original document is attached to a separation roller. It is about structure.

[Conventional technology]

An image forming apparatus such as a copying machine, an automatic document feeder installed in the image forming apparatus, and the like are provided with a sheet feeding device for feeding sheets such as copy sheets and originals. This paper feeding device is generally provided with a document tray, a paper feeding roller for feeding paper, a separation roller for preventing double feeding, a guide member for guiding a document, etc. (for example, Japanese Utility Model Laid-Open No. 60-167033). See automatic document feeder described).

An example of the structure is shown in FIG. In the figure, 101 is a main body housing, 102 is a paper feed housing, and the paper feed housing 102 has a paper feed cover 102a and a paper feed bottom plate 102b. In the main body housing 101, the pair of registration rollers 10
3, the conveyor belt 104 and the like are arranged, and in the paper feed housing 102, a paper feed roller 105, a separation roller 106, and a delivery roller.
Feed rollers such as 107 are arranged. The paper feed roller 105 and the separation roller 106 are both rotatably supported by the paper feed housing 102 via bearings (not shown), but the paper feed roller 105 is rotatably driven in the direction for feeding a document. On the other hand, the separation roller 106 is rotationally driven in the reverse feeding direction, thereby preventing the double feeding of the document.

Further, a document tray 108 is attached to the upstream end of the paper feeding unit, and the conveyance belt 104 is attached from the document tray 108.
The document guide member 109 is arranged in the area up to. The document guide member 109 has a shape that covers the rotation shaft 106a of the separation roller 106 except for the upper portion thereof, and has a paper feed bottom plate.
It is fixed to 102b with screws, and the original is placed on the separation roller.
It guides through the registration roller pair 103 side.

[Problems to be Solved by the Invention]

In the above structure, in order to effectively perform the paper separation by the separation roller 106, the relative positional relationship between the feeding roller including the separation roller 106 and the document guide member 109, especially from the document guide member 109 The amount of protrusion of the separation roller 106 and the parallelism between the two become very important. However, since the feed roller such as the separation roller 106 and the document guide member 109 are individually and independently attached to the paper feed housing 102, each attachment error may directly affect the positional relationship between the two. Therefore, it is difficult to accurately set the relative position of the two.

Further, since the document guide member 109 is often formed of a flexible material such as resin, and is easily warped or bent due to external conditions such as temperature, the document guide member 109 and the separation roller 106 or the like after assembly. The positional relationship with the feeding roller may change.

In view of the above circumstances, the present invention accurately fixes the relative positional relationship between a sheet guide member that guides a sheet such as a document or a copy sheet and a feed roller such as a separation roller with a simple structure. An object of the present invention is to provide a mounting structure for a sheet guide member that can be used.

[Means for Solving the Problems]

According to the present invention, a sheet feeding path formed between both side plates of a housing is rotatably driven, and a feed roller fixed to the both side plates and rotatably supporting a rotation shaft of the feeding roller. In a sheet feeding device including a bearing and a sheet guide member that guides a sheet to the feeding roller, a fitting portion that fits the sheet guide member in a direction substantially perpendicular to the axial direction of the bearing. The seat guide member is fixed to the housing at a position where the fitting portion fits into the bearing.

[Work]

With the above structure, the bearing fixed to both side plates of the housing and the fitting portion of the sheet guide member are fitted to each other, so that the positional relationship between the feeding roller supported by the bearing and the sheet guide member is kept constant. In this state, the seat guide member is fixed to the housing. Further, the ribs formed in the sheet guide member in the sheet conveying direction reinforce the seed guide member in the same direction, and the engagement between the engagement portion at the front end of the rib and the roller rotation shaft causes the roller rotation shaft to move. The rigidity is used to correct the shape of the sheet guide member, and the sheet guide member is also reinforced in the width direction.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS.

In FIG. 5, reference numeral 1 is a main body of the copying machine, and the main body 1 of the copying machine has a contact glass 2 (see FIG. 1 described later) on the upper surface thereof, and an image of an original document placed on the contact glass 2. Is formed on the paper supplied from the paper feed cassettes 3 and 4 at any time, and is discharged to a discharge tray (not shown).

Then, an automatic document feeder 5 is provided above the copying machine main body 1.
Is provided. The automatic document feeder 5 has a paper feed unit 6 at one end, a document carry-out unit 7 at the other end, and a conveyor belt 10 at a position above the contact glass 2 (see FIG. 1 described later).
Each of which is provided with the above-mentioned paper feeding section 6 to feed the originals (sheets) to the contact glass 2 one by one, and the originals after the completion of copying are carried out upward by the carrying belt 10 and the original carrying-out section 7 to be placed on the upper surface of the main body. Document ejecting section 8 provided
Is configured to be discharged to.

FIG. 1 shows the internal structure of the paper feed section 6. The paper feed unit 6 includes a pair of paper feed side plates 11 and a paper feed bottom plate 12.
It has a box-shaped housing consisting of, and is incorporated in the same cover 13 together with the document discharge section 7. Above the sheet feeding bottom plate 12, a mounting guide plate 14 and a mounting plate 15 are arranged.

A paper feed roller 16 and a separation roller 17 are provided in the housing.
Are arranged above and below, and a registration roller pair 18 is arranged on the downstream side, and both ends of the rotation shafts of these feeding rollers are rotatably supported by the sheet feeding side plate 11. Further, an arm 19 is attached to the rotary shaft 16a of the paper feed roller 16 so as to be swingable about the shaft 16a.
A forward feed roller 20 is rotatably attached to the tip of the. A cam 21 is arranged near the arm 19,
The rotation causes the arm 19 to swing.

The cam 21, the paper feed roller 16, and the separation roller 17 are connected to the same drive source (not shown), and their operation causes the paper feed roller 16 and the separation roller 17 to rotate in the clockwise direction in FIG. Is driven to rotate in the direction of
While the arm rotates once, the arm 19 makes one swinging reciprocating motion.

On the other hand, in the paper feeding section 6, a document tray 23, a document guide member (sheet guide member) 24, and a document guide plate 25 are arranged as a document guide member from the upstream side in the transport direction. The document tray 23 is attached to the paper feed side plate 11 so as to be rotatable about a shaft 26 penetrating the base of the document tray 23. The document guide member 24 extends from the document tray 23 to the paper feed roller 16 and the separation roller 17. Is arranged in the area up to the downstream side position. The document guide plate 25 is arranged in a region from the downstream side of the document guide member 24 to the contact glass 2 and is fitted and fixed to the paper feed bottom plate 12.

Further, a placed document detector 27 is arranged at a position just upstream of the paper feed roller 16 and the separation roller 17, and similarly, a document size detection is made at a position just upstream of the registration roller pair 18. At the position on the upstream side of the contact glass 2, the device 28 is provided with an incoming document detector 29. The document placement detector 27 is switched on when a document is set on the document tray 23 and the document is inserted to a predetermined position on the document guide member 24. Incoming document detector 29
Is to detect the currency timing of the leading edge of the document secondarily fed from the registration roller pair 18, and the driving position of the document is determined by stopping the driving of the conveyor belt 10 after a lapse of a predetermined time from this detection. To be done. The document size detector 28 is arranged at a position deviated from the center position of the fed document by a predetermined distance, and has a predetermined size (for example, B4 size).
It can be turned on only when the above document passes. In the figure, 22 is the paper feeding unit 6.
Is a connecting arm for positioning the main body of the device and the conveyor belt.

Next, the supporting structure of the separating roller 17 and the shape and mounting structure of the document guide member 24 will be described with reference to FIGS.

A bearing 30 for a separation roller 17 as shown in FIG. 2 is attached to the sheet feeding side plate 11. The bearing 30 is composed of a main body 30a having a shape in which the upper and lower parts of the outer peripheral surface of the hollow cylinder are cut out, and a collar portion 30b on a hollow disc, and is formed into an oval-shaped mounting hole formed in the paper feed side plate 11. It is fitted from the outside. The rotating shaft 17a of the separating roller 17 is rotatably supported by the bearing 30, and the E-rings 26 are attached to both ends of the rotating shaft 17a to position the shaft 17a in the thrust direction. Is being done.

On the other hand, the document guide member 24 includes the document guide portion 24a, the inclined portion 24b, the document stock portion 24c, and the document stock portion.
It has a vertical portion 24d extending downward from 24c, and has an overall width dimension that fits between both paper feed side plates 11. Projecting portions 24e extending in the document conveying direction are provided on both sides of the document guide portion 24a, and the projecting portion 24e and the document guide portion 24a substantially match the outer surface shape of the bearing body 30a. A U-shaped fitting portion 32 is formed.

Further, ribs 24f extending in the document transport direction are formed in the center of the back surface of the document guide member 24, and ribs 24g extending in the document transport direction are also formed on both outer sides thereof. Rib 24f
Has a shape in which its front end (upper end in the figure) contacts the peripheral surface of the rotary shaft 17a from the side and below (from the lower and left sides in the figure), as shown in FIG. 4 (b). Rib 24g
Has a shape such that its front end (upper end in the figure) is substantially in contact with the peripheral surface of the rotary shaft 17a of the separation roller 17 from above (right side in the figure), as shown in FIG. .

Further, a mounting hole 24h as shown in FIG. 3 is formed in a predetermined portion of the upright portion 24d of the document guide member 24. On the other hand, a mounting plate 12a (FIG. 1) facing the upright portion 24d is extended on the paper feed bottom plate 12, and a screw hole that substantially matches the mounting hole 24h is provided in the mounting plate 12a. ing.

Then, the fitting portion 32 is fitted into the bearing 30 of the separation roller 17 from a direction perpendicular to the axial direction thereof (substantially right in FIG. 1), whereby the document guide member 24 for the separation roller 17 is fitted.
With the positioning in the up-down direction and the front-back direction being performed, screw 33 is inserted into the screw hole of the mounting plate 12a through the mounting hole 24h.
The document guide member 24 is attached by screwing. With such attachment, the document guide member 24
The document guide portion 24a covers the rotation shaft 17a of the separation roller 17 from above, and the separation roller 17 projects from the document guide portion 24a by a predetermined amount. Further, the rotation of the document tray 23 in the clockwise direction in FIG. 1 is restricted by the upright portion 24d, and in the state of being rotated in the same direction to the limit,
The upper surface of the document tray 23 and the upper surface of the document stock portion 24b are arranged substantially on the same plane.

In FIG. 3, reference numeral 24i is a notch groove for allowing the lever of the above-mentioned document placement detector 27 to pass therethrough.

Next, the paper feeding operation performed by the paper feeding unit 6 to which the document guide member 24 is attached will be described. First, when a document is set on the document tray 23 and inserted into a position where the leading edge of the document comes into contact with the end of a document stopper 34 provided in the paper feed section 6, the placed document detector 27 is turned on. , Automatic document feeder 5
Is activated.

Next, when the document feeding button is turned on, the document stopper 34 is rotated so that its end portion is recessed below the document guide member 24, and the arm 19 is swung by the rotation of the cam 21. The feed roller 20 descends to the upper surface of the document. The original is fed to the position where it abuts on the registration roller pair 18 by the rotation of the feed roller 20 and the paper feed roller 16, but at the same time, the separation roller 17 rotates in the backward document feed direction, Double feeding of documents is prevented. Then, after this primary paper feeding, secondary feeding is performed by rotation of the registration roller pair 18, and the original is conveyed by the conveying belt 10 to a predetermined position on the contact glass 2.

During such a feeding operation of each feeding roller, the separation roller
The effect of preventing double feeding due to the rotation of 17 is the positional relationship between the separation roller 17 and the document guide member 24, especially the document guide portion 24a.
It is greatly affected by the amount of protrusion of the separation roller 17 from and the parallelism between the two. Here, in this embodiment, by utilizing the fitting between the fitting portion 32 of the document guide member 24 and the bearing 30 of the separation roller 17 as described above, the document guide is positioned at a position relatively good with respect to the separation roller 17. Since the member 24 is fixed, it is possible to more reliably obtain the above-described effect of preventing double feed, as compared with the conventional structure in which the separation roller 17 and the document guide member 24 are separately mounted.

Further, even when the document guide member 24 is deformed such as warped or bent after the paper feed unit 6 is assembled, the document guide member 24 is also deformed.
Since the positional relationship between the separation roller 17 and the separation roller 17 is fixed, the effect of preventing double feeding can be maintained. Further, as shown in this embodiment, if the intermediate portion of the document guide member 24 is also engaged with the rotary shaft 17a of the separation roller 27 by the ribs 24f and 24g, the rigidity of the rotary shaft 17a is utilized to make the document. There is an advantage that the shape of the guide member 24 can be corrected and the deformation thereof can be suppressed, and the influence of the deformation can be further reduced.

The manuscript guide member 24 can be mounted by inserting the fitting portion 32 into the bearing 30 and fixing the upright portion 24d to the mounting plate 12a with a screw. Also improves. Further, when it is not necessary to consider the transportability of the automatic document feeder 5, the screwing operation can be omitted.

In this embodiment, the mounting structure of the document guide member 24 in the automatic document feeder 5 is shown, but the present invention can be applied to the mounting of the sheet guide member in various sheet feeding devices, for example, in the main body of a copying machine. The same effect as described above can be obtained even if the copying paper guide member is attached to the paper feeding device.

[Advantages of the Invention] As described above, according to the present invention, the shaft fixed to both side plates of the housing is used, and the bearing and the fitting portion of the sheet guide member are fitted to each other, so that the sheet guide member and the feeding roller are connected. Since the sheet guide member is fixed to the housing in a state where the relative position is set to a good position, it is almost affected by the mounting accuracy of the sheet guide member and the feeding roller and the deformation of the sheet guide member. There is an effect that the positional relationship between the sheet guide member and the feeding roller can be easily and surely fixed with a simple structure. further,
Since the rib in the sheet conveying direction is formed in the widthwise intermediate portion of the sheet guide member, the engaging portion formed at the front end of the rib is engaged with the roller rotation shaft of the feeding roller. The sheet guide member in the sheet conveying direction can be reinforced by the engagement of the rib front end with the roller rotation shaft, and the rigidity of the roller rotation shaft is utilized to correct the shape of the sheet guide member. That is, it is possible to reinforce the sheet in the width direction, and it is possible to significantly reduce the adverse effect on the conveyance due to the deformation of the sheet guide member.

[Brief description of drawings]

FIG. 1 is a sectional view showing an essential part of an automatic document feeder according to an embodiment of the present invention, FIG. 2 is a perspective view showing a mounting structure of a document guide member and a separating roller in the device, and FIG. A rear view of the guide member, FIG. 4 (a) is a sectional view taken along line AA of FIG. 3, and FIG. 4 (b) is a sectional view taken along line BB of FIG.
FIG. 5 is a perspective view showing the appearance of the automatic document feeder and the main body of the copying machine, and FIG. 6 is a sectional view showing the main part of a conventional automatic document feeder. 1 ... Copier body, 5 ... Automatic document feeder, 6 ... Paper feed section, 11 ... Paper feed side plate (housing side plate), 17 ... Separation roller, 24 ... Document guide member (Sheet guide member) ), 24f, 24g ... rib, ... 30 ... bearing, 32 ... fitting part.

Claims (1)

[Claims] 1. A sheet feeding roller which is provided in a sheet conveying path formed between both side plates of a housing and is driven to rotate, a bearing fixed to the both side plates, and both ends of which are rotatable with respect to these bearings. In a sheet feeding device provided with a roller rotation shaft that is supported and in which the feeding roller is intermittently provided in the axial direction, and a sheet guide member that guides a sheet to the feeding roller, A fitting portion that fits in the bearing in a direction substantially perpendicular to the axial direction is provided, and a rib extending in the sheet conveying direction is formed at an intermediate portion in the width direction of the sheet guide member, and a front end of the rib is formed. The seat guide member is formed at a position where an engaging portion engageable with the roller rotation shaft is formed, the fitting portion fits with the bearing, and the engagement portion engages with the roller rotation shaft. Fixed to Mounting structure of the sheet guide member in the sheet feeding apparatus according to claim.