JP2528850B2 - Sheet material separating and feeding device - Google Patents

Description

Description: (a) Field of Industrial Application The present invention relates to a sheet feeding / separating apparatus, and more specifically, a large number of sheets in a stacked state in an electronic copying machine, a facsimile, an image reading apparatus or the like. Sheet automatic document feeder for automatically feeding the document sheets one by one to the document illuminating section and the document reading section, or a large number of copy sheets and printing sheets which are also stacked in an electronic copying machine or a printing machine. The present invention relates to a sheet material separating / feeding device such as a transfer paper automatic feeding device for automatically feeding sheets one by one to a transfer unit or the like.

(B) Conventional Technology Conventionally, as a sheet material separating / feeding device of this type,
Conveying roller 1 rotating in the conveying direction of the sheet material P shown in the figure
And a separation pad 2 are in contact with each other, and a friction roller system in which the conveyance roller 1 rotating in the conveyance direction of the sheet material P shown in FIG. 7 is composed of a pair of upper and lower endless belts 5 and 6 which are in contact with each other as shown in FIG. 7, the upper belt 5 is driven in the conveying direction of the sheet material P, and the lower belt 6 is stopped or travels in the opposite direction. Driven friction belt type, and 8th ~
It is composed of a plurality of narrow endless belts 7 and 9 arranged alternately in the upper and lower direction shown in FIG. 10, each belt 7 above the belt 7 is driven to run in the conveying direction of the sheet material P, and each belt 9 below is stopped or There is a belt separation system utilizing the strength of the waist of the sheet material P which is driven in the opposite direction. In each of the above figures, the numeral 10 indicates a pair of conveying rollers, the numeral 11 indicates a pickup roller, and the numerals 12, 15
And 13 and 16 are a drive pulley and a driven pulley, respectively.

However, in any of the above methods, the sheet material P is separated by the separating members such as the separation pad 2, the separation roller 3, and the separation belts 6 and 9, and the conveyance roller 1 and the conveyance belts 5 and 7 are separated.
Since the separating member is stopped or is rotated or driven in the opposite direction by the time the sheet is fed forward by the conveying member such as the above, as shown in FIG. The sheet material P may be bent or broken due to the collision with the separating member, and as a result, the sheet material P cannot move toward a contact point or a meeting point between the conveying member and the separating member, that is, toward the nip portion. There is a drawback that the sheet material P cannot be separated and fed. This drawback is
In particular, the damaged sheet material P is apt to appear remarkably, which is the greatest weak point of this type of sheet material separating and feeding system utilizing the frictional action.

Therefore, in order to eliminate the above-mentioned drawbacks, recently, as shown in FIG. 12, a thin plate-shaped member is formed so as to be as close as possible to the contact portion between the conveying roller 1 and the separating roller 3 which is in pressure contact with the conveying roller 1. A low friction member 17 is provided and configured so as to avoid the above-mentioned collision between the sheet material P and the separating roller 3 by the guide action of the low friction member 17, or as shown in FIG. And the separation roller 3 are brought into pressure contact with each other so that the conveyance roller 1 is rotationally driven in the conveyance direction of the sheet material P, and the separation roller 3 has a structure as shown in FIG. When the sheet material P does not exist between the conveying roller 1 and the separating roller 3 as shown in FIG. Force the sheet material P in the conveying direction When the plural sheet materials P ₁ , P ₂ are sandwiched between the conveying roller 1 and the separating roller 3 when the sheet materials P ₁ and P ₂ are sandwiched between the conveying roller 1 and the separating roller 3,
As shown, the conveying roller 1 and the friction coefficient mu ₁ of the sheet P _1, the sheet material P _1, P ₂ the friction coefficient of comrades mu _3, and the separation roller 3 and the friction between the sheet material P ₂ coefficient 2.mu. ₂ Between μ ₁ > μ
Due to the relationship of ₂ > μ ₃ , the sheet material P ₁ contacting the conveying roller 1 is fed in the conveying direction, and the sheet material P ₂ contacting the separating roller 3 is reversed by the tri-limiter 19 and the transmission mechanism 20. When the roller 3 returns the sheet to the side opposite to the conveying direction to prevent double feeding (see FIG. 15), and when only one sheet P is properly sandwiched between the conveying roller 1 and the separating roller 3, As shown in FIG. 16, the friction coefficient μ ₁ >
Due to the relationship of μ _2, the sheet material P is conveyed in the conveying direction by the conveying roller 1 and the separation roller 3 which is forcibly rotated in the conveying direction (see FIG. 15) and is dragged by the conveyed sheet material P. When a plurality of sheet materials P are again sandwiched between the conveying roller 1 and the separating roller 3, the sheets other than the sheet material P that come into contact with the conveying roller 1 are contacted as in the case of FIG. It is proposed that the material P is returned to the side opposite to the conveying direction by the reverse rotation of the separation roller 3 (see FIG. 15).

(C) Problems to be Solved by the Invention By the way, in the above-described one shown in FIG.
Is attached to the pressing contact portion between the conveying roller 1 and the separating roller 3, that is, a little front side of the nip portion, the sheet material P still bends due to the collision with the separating roller 3, resulting in low friction. If the effect of providing the member 17 cannot be expected, and conversely, if the low friction member 17 is mounted in such a state that it has entered the nip portion, the separation roller 3
However, there is a drawback in that it is technically extremely difficult to properly dispose the low-friction member 17 close to the nip portion.

Further, in the case of FIG. 13 described above, it is very difficult to set the relation between the friction coefficients μ ₁ and μ ₂ between the conveying roller 1 and the separating roller 3 and the sheet material P, the separating pressure, and the operation setting torque of the trilimiter 19. Even if the proper value of the operation setting torque of the torque limiter 19 is experimentally obtained, it is not easy to actually produce a torque limiter having such an operation setting torque, and even if it is possible to produce it, The operation limit torque of the torque limiter changes over time, and it is very difficult to maintain the initial value.

Further, as shown in FIGS. 12 and 13, in a system in which the conveying roller 1 and the separating roller 3 are constantly in pressure contact with each other with a predetermined pressing force, as shown in FIG. There is a drawback that it is extremely difficult for the sheet material P to pass between the rollers 1 and 3 after passing through the section.
In the conventional separating and feeding system, including those shown in Figs. Since the conveyance and separation of the sheet material P are determined by the unstable contact of the separating member with the sheet material P, there is a fundamental drawback that the conveyance and separation of the sheet material P is extremely unstable.

(D) Means for Solving the Problems The present invention aims to solve the above-mentioned problems, and a conveying member driven in a direction for feeding a sheet material,
A separating member that faces the conveying member and is driven in a direction opposite to the sheet material feeding direction; a pickup means that conveys the sheet material on the mounting table toward the conveying member and the separating member; and the conveying member. Detecting means for detecting the sheet material on the downstream side of the separating member in the seal material feeding direction, changing means for changing the gap between the conveying member and the separating member, and the pick-up means are set to the sheet material on the mounting table. A moving unit that moves between a contacting position and a separating position, and when the leading end of the sheet material sent by the pickup unit is detected by the detecting unit, the moving unit moves the pickup unit to the mounting table. The sheet material is separated from the sheet material stacked on the sheet, and the changing means reduces the distance between the conveying member and the separating member to separate the sheet materials one by one, and the sheet material is separated. When the rear end of the over preparative material is detected by said detecting means, said changing means is controlled so as to widen the distance between the conveying member and the separation member to the predetermined distance,
It is characterized by the following.

(E) Operation By adopting the above means, when there is no sheet material between the conveying member and the separating member, the conveying member and the separating member are separated from each other by a predetermined gap, for example, a gap through which several sheet materials can pass. Therefore, even if several sheet materials are conveyed by the pickup means in a superposed state, the sheet materials easily pass through the gap between the conveying member and the separating member without resistance. Then, when the sheet member passes through the gap between the conveying member and the separating member, and the leading end of any one of the sheet members is detected by the detecting unit, the changing unit brings the separating member and the conveying member into close proximity, The distance between the conveying member and the separating member is smaller than the predetermined distance, for example, the conveying member and the separating member come into direct contact with a predetermined pressing force, and at the same time, the moving means causes the pickup means to move the sheet material to the sheet material. Move away from. Then, the sheet material contacting the conveying member is conveyed in the feeding direction by the conveying member due to the frictional contact force between the conveying member and the sheet material contacting the separating member is separated by the frictional contact force between the separating member. The sheet material returned by the member in the direction opposite to the feeding direction and finally left between the conveying member and the separating member has a frictional contact force between the conveying member and the sheet material, Due to the greater frictional contact force between them, they are fed in the feed direction. At this time, since the pick-up means is separated from the sheet material on the mounting table, it does not hinder the feeding of the sheet material in the opposite feeding direction by the separating member, and the double feeding is prevented to ensure the reliability. To be separated. In this way, the stacked sheet materials are sequentially separated one by one and fed to the next work process or the like. Then, when the detecting means detects the trailing end of the separated sheet material, the conveying member and the separating member are expanded to a predetermined interval, and in combination with the fact that the conveying member returns the sheet other than the conveying sheet, Sheet material is not sent out in a row.

(F) Example Hereinafter, examples embodying the present invention will be described with reference to the drawings.

As shown in FIG. 1, the sheet-shaped document automatic feeding device 21 is configured to feed a sheet-shaped document P, which is placed on the document table 22 in a stacked state by a pick-up roller 23, to separate and feed the document sheet P. 25, and the original separating and feeding unit 25
The sheet-shaped originals P separated one by one are fed to the downstream original reading section and the like through the pair of conveying rollers 26.

As shown in detail in FIG. 2, the document separating / feeding unit 25 directs the sheet-shaped document P from the document placing table 22 side toward the conveying roller pair 26 side by a drive source (not shown) fixed to a shaft 27. A transport roller 29 which is rotated so as to feed, and the roller
It is located opposite to the lower side of 29 and has a shaft driven by a drive source (not shown).
30, a driving side pulley 31 fixed to the shaft 30, a transmission belt 32 wound around the pulley 31, a driven pulley 33 rotated by the belt 32, and a shaft 35 to which the pulley 33 is fixed.
And a separation roller 36 which is rotated in the direction opposite to the feeding direction of the sheet-like document P via a roller, and both shaft ends of a shaft 35 to which the roller 36 is fixed swing about the shaft 30 respectively. The lever members 37, 37, which can be rotated, are rotatably supported on one end side.

Further, a rod-shaped coupling member 39 is fixed to the other end side of the lever members 37, 37 so as to connect them, and one side of the coupling member 39 is provided between the lever member 37 and the proper fixing portion of the apparatus main body. A tension spring 40 is stretched, and as shown in FIG. 1, the lever members 37, 37 are rotated about the shaft 30 in the direction B shown in the drawing, that is, in the counterclockwise direction until they come into contact with the stopper 41, and the separation roller 36 is moved. The connecting member is separated from the conveying roller 29 by a predetermined distance, and
Solenoid means (changing means) 42 is disposed on the other side of 39, and when the solenoid means 42 is excited, the plunger 43
Then, the lever members 37, 37 are rotated in the direction A in the drawing, that is, in the clockwise direction against the tension spring 40 via the tension spring 45, so that the separation roller 36 is brought into contact with the conveying roller 29 with a predetermined pressing force. Is configured.

Further, as shown in FIG. 1, the conveying roller 29 and the separating roller 36 are located close to the front side (downstream side) of the sheet-shaped document P in the feeding direction, for example, by a photoelectric method, an ultrasonic method, or a contact method. A sheet-like document detection sensor 46 of an appropriate system or the like is provided, and the above-mentioned solenoid means 42 is excited by the detection action of the sheet-like document P by the sensor 46 and a solenoid means (moving means) not shown. The excitation of the pickup roller 23 separates the pickup roller 23 upward from the sheet-shaped original P on the original table 22.

Then, the above-mentioned sheet-shaped document automatic feeding device 21 is incorporated in the document reading device 47 in a manner as shown in FIG.

Incidentally, what is denoted by the reference numeral 49 below the document placing table 22 in FIG. 1 is rotated by the sheet-like document P placed on the document placing table 22 and the presence or absence of the sheet-like document not shown. It is a sensor lever member that turns on the detection sensor.

Since the present embodiment is configured as described above, a large number of sheet-like originals P are placed on the original placing table 22 and the sensor lever member 49 is rotated, so that a sheet-like original presence / absence detection sensor (not shown) is provided. When the feeding of the original P is instructed in the on-operation state, the pickup roller 23 is lowered onto the laminated sheet-like original P and is rotationally operated so that the sheet-like original P is fed.
Feeding is started (see FIG. 4). Similarly, while the sheet-shaped original document P is not fed between the transport roller 29 and the separation roller 36, which are also started to rotate, the separation roller 36 is, for example, several sheet-shaped original documents P from the transport roller 29. Are separated from each other by a gap Δl that can pass in a superposed state, even if, for example, several sheet originals P are fed by the pickup roller 23 in a superposed state, the sheet originals P are conveyed. And smoothly passes through the gap Δl between the separation roller 36 and the separation roller 36 (see FIG. 4). When the leading edge of any one of the sheet-shaped originals P that has passed through the gap Δl between the transport roller 29 and the separation roller 36 is detected by the sheet-shaped original detection sensor 46, the solenoid means 42 is excited and the plunger 43 is excited. , The lever members 37, 37 are rotated in the direction of A in the figure against the tension spring 40 via the tension spring 45.
Is raised in a direction in which it comes into contact with the conveying roller 29 with a predetermined pressing force. Then, of the several sheet-shaped originals P sandwiched by the conveying roller 29 and the separating roller 36, the sheet-like original P that comes into contact with the conveying roller 29 is fed by the frictional contact force with the conveying roller 29. Sheet-like original P that is conveyed in the direction of the arrow and comes into contact with the separation roller 36
Is returned in the direction opposite to the feeding direction by the frictional contact force with the separating roller 36 (see FIG. 4). Thus, only one sheet-like original P left between the conveying roller 29 and the separating roller 36 is finally the sheet-like original P by the conveying roller 29.
Based on the fact that the frictional contact force to the sheet is larger than the frictional contact force of the separating roller 36, the sheet is fed to the next sheet-shaped document reading unit (see FIG. 4). When the trailing edge of the first sheet-shaped document P moves away from the detection effect of the sheet-shaped document detection sensor 46, the conveying roller 29 and the separation roller are again detected.
A gap Δl is formed between the same and 36, and at the same time, the pickup roller 23 is lowered (see FIG. 4), and the above-mentioned
The above process is repeated, and the sheet-like original P in the stacked state becomes 1
The sheets are sequentially fed to the document reading section.

Incidentally, in the above-mentioned embodiment, the separation roller 36
Shows that the transfer roller 29 moves closer to the side, the transfer roller may be configured to move to the separation roller side, or the transfer roller and the separation roller may be configured to move closer to each other. Good. In addition, a sheet-shaped document detection sensor
Although it has been described that the separation roller 36 comes into contact with the conveyance roller 29 with a predetermined pressing force when the 46 is turned on, if the gap between the separation roller 36 and the conveyance roller 29 is equal to or less than the thickness of the sheet-like document P, the separation roller 36 does not necessarily come into contact. do not need. Further, although the separating and feeding unit 25 uses the rollers of the conveying roller 29 and the separating roller 36, the separating feeding unit 25 may use a belt.

(G) Effect of the Invention As described above, according to the present invention, the leading edge of the sheet material is always reliably sandwiched between the conveying member and the separating member without colliding with the separating member rotating in the reverse direction, and then separated and fed. Therefore, it is possible to prevent the occurrence of jams and defective feeding, and it is possible to satisfactorily feed even a sheet material having a slight defect at the leading end or a thin thin sheet material,
Furthermore, since there is no mechanism that requires delicate mounting work, adjustment work, etc., and because the mechanism is extremely easy to manufacture and there is no risk of change over time, it is inexpensive, easy to handle, and stable in performance. A sheet material separating / feeding device is obtained.

Also, when the tip of the sheet material is detected by the detection means,
Since the distance between the conveying member and the separating member is reduced and the pick-up means is separated from the sheet material, the pushing of the sheet material by the pick-up means is eliminated, and there is no hindrance to the feeding of the sheet material in the opposite feeding direction by the separating member. No double feed is reliably prevented.

Further, when the trailing end of the separated sheet material is detected by the same detecting means, the conveying member and the separating member are separated from each other, so that it is possible to prevent the next sheet from being fed out and unnecessary feeding and feeding of the sheet material.

Moreover, since the control is performed based on one detection means,
Mechanical (hard) and control (soft) structures are simplified.

[Brief description of drawings]

1 to 4 are views relating to a sheet material separating and feeding apparatus according to the present invention. FIG. 1 is a side sectional view of an essential part thereof, FIG. 2 is a perspective view of the essential part thereof, and FIG. FIG. 4 is an application diagram of the apparatus, and FIG.
FIGS. 5 to 15 show the main structure of the sheet material separating and feeding apparatus according to the conventional example, and FIGS. 16 and 17 show general operation explanatory views. 21 ... Sheet material separating / feeding device (sheet-shaped document automatic feeding device), 29 ... Conveying member (conveying roller), 23 ... Pickup means (pickup roller), 36 ... Separating member (separating roller), 42 ...... Change means (solenoid means), 46 ...
Detecting means (sheet original detection sensor), P ... Sheet material (sheet original).

Claims (1)

(57) [Claims] 1. A conveying member driven in a sheet material feeding direction, a separating member facing the conveying member and driven in a direction opposite to a sheet material feeding direction, and a sheet material on a mounting table. Pickup means for conveying toward the conveying member and the separating member; detecting means for detecting a sheet material on the downstream side of the conveying member and the separating member in the sheet material feeding direction; and a gap between the conveying member and the separating member. And a moving means for moving the pickup means to a position in contact with the sheet material on the mounting table and a position separated from the sheet material, and the tip of the sheet material sent out by the pickup means is When detected by the detection unit, the moving unit separates the pickup unit from the sheet material stacked on the mounting table, and the changing unit separates the conveying member and the separating unit. By reducing the distance between the sheet material 1
When the rear end of the separated sheet material is detected by the detection means, the changing means is controlled to widen the distance between the conveying member and the separating member to a predetermined distance. A sheet material separating and feeding device.