JPH075071Y2 - Sheet transport device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] This invention relates to a copying machine, a laser printer, a liquid crystal printer,
An automatic document feeder that automatically feeds a document onto a platen of a sheet feeding device installed in a sheet intake port provided in an image forming apparatus such as a printing machine or an image processing apparatus such as a copying machine, a facsimile, or an image reader. For example, the present invention relates to a sheet conveying device that is provided in, for example, a sheet conveying device while separating sheets.

[Conventional technology]

The sheet conveying device, for example, the separating portion of the automatic document feeder,
For example, there is one disclosed in JP-A-59-198243.
As shown in FIG. 3 (which is shown in FIG. 10 in the present application) of the device of this publication, the endless belts 10a, 10b for conveyance and the endless belts 11a, 11b, 11c for separation are alternately arranged. A coefficient of friction M ₁ between the endless belts 10 a, 10 b for conveyance and the sheet 16,
The relationship of M ₁ > M ₂ > M ₃ between the friction coefficient M ₂ between the separation endless belts 11 a, 11 b, 11 c and the sheet 16 and the friction coefficient M ₃ between the plurality of sheets 16 is expressed as follows. After being formed, the plurality of sheets 16 are separated into one sheet.

[Problems to be solved by the device]

However, as shown in FIG. 10, the sheet 16 is not in contact with the outer edges of the separation endless belts 11a and 11c, so that the rotation loss of the separation endless belts 11a and 11c occurs.

Here, the conveying endless belts 10a and 10b and the separation endless belt 1
Conveying force when the sheet 16 is in contact with both edges of 1b
F ₁ , the transfer force when in contact with one edge is F ₂ (F ₁ ≧
F ₂ ), the relationship between the sum of the conveying forces of the conveying endless belts 10a, 10b and the sum of the separating endless belts 11a, 11b, 11c is as follows.

4F ₁ ≧ 2F ₁ + 2F _{2 In} this way, the difference in the conveying force between the total conveying force of the conveying endless belts 10a, 10b and the conveying force of the separating endless belts 11a, 11b, 11c is small, so the sheet In order to convey 16 while separating them into one sheet, the difference in the friction coefficient of the belt must be increased.

However, if the difference in the coefficient of friction between the belts is increased, it may not be possible to deal with the difference in hardness between the two materials, and the materials must be changed. Therefore, there are restrictions on the selection of the belt material.

[Purpose of device]

It is an object of the present invention to provide a sheet conveying device capable of reliably contacting a sheet with a feeding means and a separating means and performing separation and conveyance with little loss.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention has a paper feed path formed by a pair of guide members, a feeding means having a plurality of rotating bodies for carrying sheets along the paper feed path, and the feeding means. And a separating means for preventing the conveyance of the sheet following the sheet conveyed by the feeding means, the rotating body of the feeding means and the separating means. Are alternately arranged in the sheet width direction, and in the sheet conveying device in which the rotating members of the feeding means and the separating means are arranged to overlap each other in a direction orthogonal to the plane of the conveyed sheet, A pressing member for pressing the sheet against the outer edge of the rotating member of the feeding unit located at the outermost end in the width direction is provided on the guide member on the side facing the feeding unit.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> As shown in FIG. 1, an automatic document feeder 5 is mounted on an image forming apparatus, for example, a platen 3 of a copying machine 1.

The automatic document feeder 5 includes, for example, a document tray 7 that forms a part of a document storage unit, a separation / feed unit 9 that separates and sends the document set on the document tray 7 into one sheet.
The original sent from the separating / feeding unit 9 is conveyed on the platen 3, the conveying unit 11 is turned over, the reverse discharging unit 13 reverses and discharges the copied original, and the reverse discharging unit 13 is discharged. An accommodation tray 15 for accommodating an original is provided so that the original can be automatically fed and ejected.

Further, the transport unit 11 and the reverse discharge unit 13 are integrated with the cover C and are attached to the rear surface of the copying machine 1 via a hinge so as to be openable and closable, and the cover C is placed on the upper side together with the transport unit 11 and the reverse discharge unit 13. By opening, the document can be set on the platen 3 by a manual operation.

As shown in FIG. 2, the separating / feeding unit 9 includes a sensor S1 for detecting whether or not a document is set in the paper feed port 17, and a feeding roller 19 for feeding the document set in the paper feed port. The document holder 21 for pressing the document inserted into the sheet feed port 17 against the feeding roller 19 and the sheet feeding path 22 formed by the guide member, for example, the sheet feeding guides 18 and 20 are provided so as to face the sheet feeding roller. A feeding unit 23 that conveys the document sent by 19,
Separation means that is provided so as to face the feeding means 23 and that recedes the original document that follows the upper surface of the original document conveyed by the feeding means 23.
25, a sensor S2 for detecting the leading edge of the document separated and fed by the feeding means 23 and the separating means 25, a registration roller 27 for registering the leading edge of the document, and a pressure contact roller 29.

As shown in FIGS. 3A, 3B, and 3C, the feeding roller 19 is composed of a synthetic resin portion 33 attached to the rotary shaft 31 and a rubber ring 35, and is driven by the motor M1. . A flange 37 is formed on the left and right of the synthetic resin portion 33, and an arc portion 39 and a cutout portion 41 are formed between the flanges 37. Then, a rubber ring 35 is attached to the circumferential surfaces of the arc portion 39 and the cutout portion 41, and an arc-shaped conveying portion 42 that comes in contact with the original document and sends out the original document, and a specific contact with the original document that is continuously provided to the conveying part 42. The cutout portion 44 is formed. The contact surface of the flange 37 with the original has a smaller coefficient of friction than the peripheral surface of the transport section 42.

As shown in FIG. 4 (A), the document retainer 21 rotates about a first arm 45 that rotates about a shaft 43 and a shaft 47 that is provided on the tip end side of the first arm 21. The second arm 49 is provided, the document is pressed against the feeding roller 19 by the rounded portion on the tip side of the first arm 21, and the tip of the document is held by the tip of the second arm 49. The document retainer 21 has a shaft 43 and a motor M1 connected by a cam and a link mechanism so that the document retainer 21 moves up and down every time an elliptical pulley 53 described later rotates once.

The feeding means 23 includes an elliptical pulley 53 attached to a rotating shaft 51 driven by a motor M1, a pulley 57 attached to the rotating shaft 55, and a rotating member stretched between the pulleys 53, 57, for example, a feeding member. A belt (two-stage belt) 59 is provided, and these are provided in three rows as shown in FIG. 4 (B). In addition, the feeding belt
59 is a stack of two separate belts in two layers.

As shown in FIG. 2, backup means 61 for preventing the belt from hanging down is provided inside the feeding belt 59.

The separating means 25 is stretched between the pulley 65 attached to the rotating shaft 63 driven by the motor M1, the pulley 69 attached to the rotating shaft 67, and the pulleys 65 and 69 as shown in FIG. 4 (A). And a separation belt 71 as a rotating member, which are provided in two rows as shown in FIG. 4 (B).

On the other hand, as shown in FIG. 4 (B), the lower surface of the paper feed guide 18 is pushed by pressing the original document on the outer edge of the feeding belt 59 on the outer side of the original width direction of the feeding belt 59 located on both ends of the original document in the width direction. Contact members, for example pressing ribs 12 and 14, are provided.

In addition, the paper feed guide 20 has three elliptical pulleys 53 on both sides,
When the elliptical pulley 53 is in the position as shown in FIG. 4 (A), the rib 24 which is slightly higher than the rubber surface of the feeding belt 59 is provided.

By the way, the speed ratio of the feeding belt 59 and the separation belt 71 is set to, for example, 10: 6, and the feeding belt 59 is more separated than the separation belt 71.
Rotate faster.

As shown in FIG. 1, the conveyor 11 is provided with a conveyor belt 85 stretched between rollers 81 and 83, and pressure rollers 87, 89, 91 and 93 for pressing the conveyor belt 85 against the platen 3. .

The reverse discharge unit 13 is provided with a reverse path 95, conveyance rollers 97 and 99, a discharge sensor S3, and discharge rollers 101 and 103. It is driven by the motor M3.

In the configuration as described above, this device operates as follows.

In the initial state, the feeding roller 19 and the elliptical pulley 53 are in the positions shown in FIG. The document retainer 21 is raised.

When you insert the original into the paper feed slot 17 with the copy side of the original facing down,
The document is detected by the sensor S1, and the document rides on the rib 24 and is set smoothly without hitting the rubber surface of the feeding belt 59. Next, an operation panel (not shown) is operated to set copy conditions.

When a print button (not shown) is pressed in such a state, the motor M1 rotates. This allows the document holder 21
The shaft 43 rotates clockwise in the figure, and the document holder 21 falls on the document. Therefore, the leading end of the first arm 45 presses the document against the feeding roller 19, and the leading end of the second arm 49 holds the leading end of the document.

In addition, the feeding roller 19 and the elliptical pulley are driven by the operation of the motor M1.
53 and roller 65 rotate. Therefore, the feeding roller 19 rotates in the feeding direction from the state in which the flange 37 is in contact with the bottom sheet,
Gradually send out the manuscript. Then, when the edge of the cutout portion 44 comes into contact with the document, the conveyance force becomes large, and the conveyance portion 42 sends it out vigorously.

At that time, as shown in FIG. 4, since the overlap amount between the feeding belt 59 and the separating belt 71 is small and the pressure acting on the original is weak, the original is smoothly gripped between the feeding belt 59 and the separating belt 71. Be done.

Then, as shown in FIG. 8, the originals P become wavy by the feeding belt 59 and the separating belt 71, which are alternately arranged, and the left and right edges of the three feeding belts 59 come into contact with the lower surface of the original P, and The left and right edges of the two separation belts 71 and the two pressing ribs 12 and 14 contact the upper surface of P.

When the elliptical pulley 53 is rotated and becomes as shown in FIG. 5, the overlap between the feeding belt 59 and the separation belt 71 is increased,
The feeding force of the feeding belt 59 increases and the separating performance of the separating belt 71 also improves, so that the document is reliably separated and only one sheet is fed. That is, a document that follows the document sent by the feeding belt 59 is repelled by the separation belt 71 and separated into one sheet.

When the elliptical pulley 53 further rotates and becomes as shown in FIG. 6, the conditions are almost the same as those in FIG. The leading edge of the document passes through the separating section, and the rear side of the document has little change in the overlap amount of the belts 59 and 71, and the document is fed with a substantially constant conveying force and separating force.

When the elliptical pulley 53 further rotates and becomes as shown in FIG. 7, the conditions are almost the same as those in FIG. The second and subsequent documents are belts
Even if a case remains between the 53 and 71, the separation performance is improved, so the second and subsequent originals are pushed out from between the belts 53 and 71. Then, in the process of returning to the state of FIG. 4, the shaft 43 rotates counterclockwise and the document holder 21 rises.

By the way, when the sensor S2 detects the leading edge of the separated document, the motor M1 stops after a predetermined time T1. Here, the predetermined time T1 is set to a time sufficient for the document to bend after the leading edge of the document passes the sensor S2 and then contacts the rolling contact portion of the registration roller 27 and the pressure contact roller 29. Therefore, the front end of the bent original is registered.

Then, after a lapse of a predetermined time T2 (T2> T1) after the sensor S2 is turned on, the motor M2 is slightly rotated so that the leading edge of the document is gripped between the registration roller 27 and the pressure contact roller 29, and the state of waiting without bending is waited. Let

When the copy preparation of the copying machine 1 is completed in such a state, the motors M1 and M2 rotate, and the registration roller 27 and the feeding roller 1
9, the feeding belt 59 sends out the original. The delivered document is delivered to the platen 3. Then, when the trailing edge of the document is detected by the sensor S2, the motor M2 is stopped, and the subsequent rotation of the motor M1 causes the first document advance operation in the same manner as described above, and the registration roller 27 and the pressure contact roller. Hold with the leading edge of the original in 29 and wait.

On the other hand, at the same time as the motor M2 rotates, the motor M3 rotates, and the conveyor belt 85 conveys the platen 3 onto the platen 3 and sets the reference position. Then, the copying operation is performed.

When copying is completed, the conveyor belt 85 rotates and the platen 3
The document is sent from the top to the reversal path 95, and the document is reversed and discharged. At that time, if the rear edge of the document is detected by the sensor S3,
The original document that has been delivered first is delivered to the platen 3. The document discharged from the reverse path 65 is stored in the storage tray 15.

According to the embodiment described above, the following effects can be obtained.

(1) As shown in FIG. 8, a pressing rib for pressing the original P on the outer edge of the feeding belt 59 on the outer side of the original width of the feeding belt 59 located at both ends of the lower surface of the paper feed guide 18 in the original width direction. Since 12 and 14 are provided, both widthwise ends of the document P also come into contact with the outer edges of the feeding belt 59, and the loss of the conveying force by the feeding belt 59 is small.

Here, the conveyance force when the document P is in contact with the edge due to the overlap (overlap) of the feeding belt 59 and the separation belt 71 is F ₁ , and the document P is pushed to one side of the feeding belt 59 by the pressing ribs 12 and 14. The conveyance force when it is in contact with the edge of F ₂ (F ₁
≧ F ₂ ), the relationship between the sum of the conveying force of the separation belt 71 and the sum of the feeding belt 59 is as follows.

4F ₁ <4F ₁ + 2F _{2 In} this way, the feeding belt is calculated from the sum of the conveying forces of the separation belt 71.
The total sum of the conveying forces of 59 becomes larger, and the material of the feeding belt 59 and the separating belt 71 may be the same, or the difference in the coefficient of friction may be small.

Therefore, there is a wide range of choices for the materials of the feeding belt 59 and the separation belt 71, and the optimum belt can be selected.

(2) Since both ends of the original P in the width direction also contact the outer edges of the feeding belt 59, the engaging state of the original P with the feeding belt 59 and the separation belt 71 is maintained regardless of the curl of the original P and the change in humidity. It is always uniform and stable separation can be performed.

<Second Embodiment> The sheet conveying device of the present invention can be applied to an automatic paper feeding device 103 attached to a printer or a printer 100 of a typewriter as shown in FIG.

First, the printing apparatus 100 includes a platen 105 attached to a platen shaft 104, a head carriage 106 that can reciprocate laterally along the platen 105, and a head carriage 106.
Print head 107 attached to the platen, a guide 108 and pinch rollers 109, 110 provided along the peripheral surface of the platen 105.
It has and.

On the other hand, the automatic paper feeder 103 has arcuate support portions 112 fitted to the platen shafts 104 on the side frames 111 on both sides.

Inside the side frame 111, a lock lever 113 has an intermediate portion supported by a shaft 114. The lock lever 113 fixes the automatic paper feeding device 103 to the platen shaft 104, and has an engaging portion 115 that engages with the platen shaft 104 at one end.

A separation / conveyance unit 101 is provided between the side frames 111, and those having the same reference numerals as those in the above-mentioned embodiment have the same structure.

A guide 133 is provided in front of the separation / conveyance unit 101.
Further, the manual feed guide 135 and the paper discharge guide 136 are attached with forming a manual feed slit 137. A paper ejection frame 138 for holding the paper ejection is detachably attached to the manual feed guide 135.

A paper discharge roller 140 is attached to the drive shaft 139 on the paper discharge guide 136, and guides the paper to the frame 138 side together with the paper discharge guide 142 rotating around the shaft 141. It should be noted that the paper discharge roller 140 receives a driving force from the platen shaft 104.

In such a configuration, the device operates as follows.

It

When a printing command is given to the printing apparatus 100 from a computer or the like in such a state, the platen 105 rotates and the separating / conveying unit 101 separates and feeds the sheet into one sheet, and the sheet guides the manual feed guide plate 135. It is supplied between the platen 105 and the guide 108 through the space.

When the print head 107 wound around the platen 105 prints, it is guided by the paper discharge guide 142 and discharged by the paper discharge guide 142 and the paper discharge roller 140.

[Modification]

Although the two embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and for example, in the above-mentioned embodiments, pressing ribs 12 and 14 are used as pressing members.
However, the sheet may be pressed against the feeding means or the separating means by a plastic sheet or the like.

[Effect of device]

According to this invention, the paper feed path formed by the pair of guide members, the feeding means having the plurality of rotators that convey the sheet along the paper feed path, and the number of the rotators of the feeding means. And a separating means for preventing the conveyance of the sheet following the sheet conveyed by the feeding means, and the rotating bodies of the feeding means and the separating means alternate in the sheet width direction. In the sheet conveying device in which the rotating members of the feeding unit and the separating unit are arranged so as to overlap each other in the direction orthogonal to the plane of the sheet to be conveyed, at the outermost end in the sheet width direction. Since the pressing member that presses the sheet against the outer edge of the rotating member of the feeding unit located is provided in the guide member on the side facing the feeding unit, the sheet is the same in all of the feeding unit and the separating unit. Rolling can contact the edge of the member, any loss of its conveying force of the feeding means and the separating means is minimized.

[Brief description of drawings]

1 to 8 are views showing an embodiment of the present invention.
FIG. 2 is a sectional view showing the entire structure of the automatic document feeder, FIG. 2 is a sectional view showing the structure of the separating / feeding unit, and FIGS. 3 (A) and 3 (B).
4C is a sectional view showing the structure of the feeding roller, FIG.
(B) to FIGS. 7 (A) and 7 (B) show document pressing, feeding means,
FIG. 8 is a sectional view for explaining the constitution and operation of the separating means, and FIG. 8 is a sectional view for explaining the effect of the embodiment. FIG. 9 is a diagram showing another application example of the present invention. FIG. 10 is a diagram for explaining a conventional technique. 5 ... Automatic document feeder (sheet conveying device) 12, 14 ... Pushing rib (pressing member) 18, 20 ... Paper feed guide (guide plate) 23 ... Feeding means 25 ... Separating means 59 ... … Feeding belt (rotating member) 71 …… Separating belt (rotating member) 103 …… Automatic paper feeder (sheet conveying device)

Claims (1)

[Scope of utility model registration request] 1. A paper feed path formed by a pair of guide members, a feeding means having a plurality of rotating bodies for carrying sheets along the paper feeding path, and a number of rotating bodies of the feeding means. The rotating body of the feeding means and the separating means is alternately arranged in the sheet width direction, and has one less rotating body, and separation means for preventing the conveyance of the sheet following the sheet conveyed by the feeding means. In the sheet conveying device, which is arranged and overlaps the rotating member of the feeding means and the rotating member of the separating means in the direction orthogonal to the plane of the conveyed sheet, the sheet conveying device is positioned at the outermost end in the sheet width direction The sheet conveying apparatus, wherein a pressing member for pressing a sheet against the outer edge of the rotating member of the feeding unit is provided on the guide member on the side facing the feeding unit.