JP2528851B2 - 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 to run in the conveying direction of the sheet material P, and the lower belt 6 is stopped or run in the opposite direction. Driven friction belt type and 8th-10th
A plurality of narrow endless belts alternately arranged in the upper and lower direction shown in the figure
A belt using the waist strength of the sheet material P that is composed of 7, 9 and that drives the belts 7 above it in the conveying direction of the sheet material P and drives the belts 9 below to stop or drive in the opposite direction. There is a separation type. In each of the above figures, reference numeral 10 indicates a pair of conveying rollers, reference numeral 11 indicates a pickup roller, and reference numerals 12, 15 and 13, 16 respectively indicate a driving pulley and a driven pulley. Is.

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 separating roller 3 are pressed against each other so as to rotate the conveying roller 1 in the conveying direction of the sheet material P, and the separating roller 3 has a torque limiter 19 and a transmission mechanism having 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 coefficient of friction between the separation roller 3 and the sheet material P ₂ mu ₂ Between μ ₁ > μ ₂
Due to the relationship of> μ ₃ , the sheet material P ₁ contacting the transport roller 1 is fed in the transport direction, and the sheet material P ₂ contacting the separation roller 3 is reversed by the trilimiter 19 and the transmission mechanism 20. When the sheet material P is properly held between the transport roller 1 and the separation roller 3 by being returned to the side opposite to the transport direction by 3 to prevent double feeding (see FIG. 15), 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 relationship 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 set torque of the torque limiter 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. The detecting means for detecting the sheet material on the downstream side of the separating member in the seal material feeding direction, the pressing force increasing / decreasing means for increasing / decreasing the pressing force of the conveying member and the separating member, and the pickup means are provided on the mounting table. A moving unit that moves to a position in contact with the sheet material and a position to separate from the sheet member,
When the front end of the sheet material sent out by the pickup means is detected by the detection means, the moving means separates the pickup means from the sheet material stacked on the mounting table, and the pressing force increasing / decreasing means. Sets the pressing contact force between the conveying member and the separating member to a high value so that the sheet material is separated and fed, the sheet materials are separated one by one, and the rear end of the separated sheet material is detected. When detected by the means, the pressing force increasing / decreasing means is controlled so as to set the pressing contact force between the conveying member and the separating member low enough to allow the sheet material conveyed by the pickup means to pass. It is characterized by

(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 in contact with each other only with a small pressing force, and therefore, the number of times by the pickup means is increased. Even if the sheet materials are conveyed in a superposed state, the sheet materials easily pass between the conveying member and the separating member. Then, the sheet material passes between the conveying member and the separating member, and when one of the ends of the sheet material is detected by the detecting means, the pressing force increasing / decreasing means pushes the separating member and the conveying member. The pressure is increased so that the conveying member and the separating member come into contact with each other with a predetermined pressing contact force, and at the same time, the moving unit moves the pickup unit to separate from the sheet material. Then, the sheet material contacting the conveying member is conveyed in the feeding direction by the conveying member due to the frictional contact force with the conveying member, and the sheet material contacting the separating member is caused by the separating member due to the frictional contact force between the separating member. One sheet material returned to the opposite direction 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 between the separating member and the sheet material. It is sent in the feeding direction based on the fact that it is greater than the frictional contact force. On this occasion,
Since the pick-up means is separated from the sheet material on the mounting table, it does not interfere with the feeding of the sheet material in the opposite feeding direction by the separating member, and the double feeding is prevented and the sheet material is reliably 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
The shaft 3 is placed opposite to the lower side of 29 by a drive source (not shown).
0, a drive 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 couple them, and a solenoid means 40 is arranged on one side of the coupling member 39, and the solenoid means 40 is provided. The plunger 41 of the means 40 and the coupling member 39 are connected via a tension spring 42, and the solenoid means
When 40 is not excited, the plunger 41 is pulled out until it comes into contact with the stopper 43, whereby a weak spring force of the tension spring 42 causes the coupling member 39 and the lever members 37, 37.
The separation roller 36 is pressed against the conveyance roller 29 via the
Further, when the solenoid means 40 is excited, the plunger 41 is retracted by a predetermined stroke from the contact state with the stopper 43, and the tension spring extended thereby
The separating roller 36 is configured to be pressed into contact with the conveying roller 29 by a predetermined pressing force via the coupling member 39 and the lever members 37, 37 by a strong spring force of 42.

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 45 of an appropriate method such as a method is provided, and the above-mentioned solenoid means 40 is excited by the detection action of the sheet-like document P by the sensor 45 and a solenoid means (moving means) not shown. The pickup roller 23 is separated upward from the sheet-shaped document P on the document mounting table 22 by the exciting action of.

Then, the above-mentioned sheet-shaped document automatic feeding device 21 is incorporated in the document reading device 46 in a manner as shown in FIG.

In addition, what is denoted by reference numeral 47 below the document placing table 22 in FIG. 1 is rotated by the sheet-like document P placed on the document placing table 22 so that the presence or absence of a 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 47 is rotated, so that a sheet-like original presence 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). Then, while the sheet-shaped original P is not yet fed between the conveying roller 29 and the separating roller 36 whose rotation has been started, the separating roller 36 exerts only a weak pressing force on the conveying roller 29. Since they are not in contact with each other, even if, for example, several sheet-shaped originals P are fed by the pickup roller 23 in a superposed state, the sheet-shaped originals P are kept superposed on each other and the conveyance roller 29 and the separation roller 36 are in contact with each other. It easily passes through the gap (see Figure 4). Then, when the leading edge of any one of the sheet-shaped originals P passing between the transport roller 29 and the separation roller 36 is detected by the sheet-shaped original detection sensor 45, the solenoid means 40 is excited and the plunger 41 is moved. Since the tension spring 42 is extended by the retracting operation, the increased spring force of the tension spring 42 is transmitted to the separating roller 36 via the coupling member 39 and the lever members 37, 37, and the separating roller 36 is conveyed to the conveying roller 29. Contact with a predetermined strong pressing force. Then
Of the several sheet-shaped originals P held 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 conveyed in the feeding direction by the frictional contact force with the conveying roller 29, and The sheet-like document P that contacts the separation roller 36 is returned in the direction opposite to the feeding direction by the frictional contact force with the separation roller 36 (see FIG. 4). In this way, the remaining 1 between the conveying roller 29 and the separating roller 36 is finally obtained.
Based on the fact that the frictional contact force of the conveying roller 29 with respect to the sheet-like document P of only the sheet-like document P is larger than the frictional contact force of the separating roller 36 with respect to the sheet-like document P, the sheet-like document of the next stage is obtained. It is fed to the reading section (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 45, the solenoid means 40 is de-energized, and the pressing contact force of the separation roller 36 against the transport roller 29 is weak again. At the same time, the pickup roller 23 is lowered (see FIG. 4), and the above-described steps 1 to 3 are repeated again, and the sheet-shaped originals P in the stacked state are sequentially fed one by one to the original reading section.

Incidentally, in the above-mentioned embodiment, the separation roller 36
Although the pressing force is applied to the above, the pressing force may be applied to the conveying roller 29 or the separation roller 36 and the conveying roller 29. Further, although the one in which the rollers of the conveying roller 29 and the separating roller 36 are used as the separating / feeding unit 25 has been described, these may be those using a belt.

(G) Effect of the Invention As described above, according to the present invention, the sheet material is securely inserted and pressed between the conveying member and the separating member and then separated and fed. A mechanism that prevents the occurrence of defects, and enables particularly good feeding of sheet materials with a slight defect at the tip or thin and weak sheet materials, and requires delicate mounting work and adjustment work. Since it does not exist at all, and there is no mechanism that is easy to manufacture and that does not change over time, a sheet material separating / feeding device that is inexpensive, easy to handle, and stable in performance can be obtained.

Also, when the tip of the sheet material is detected by the detection means,
Since the pressing contact force between the conveying member and the separating member is set to be low and the pickup means is separated from the sheet material, the pushing of the sheet material by the pickup means is eliminated, which hinders the feeding of the sheet material in the opposite feeding direction by the separating member. The 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), 37 , 40, 42 ... Pressing force increasing / decreasing means (lever member, solenoid means, tension spring), 45 ... Sheet material 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. A pickup means for conveying the sheet toward the conveying member and the separating member; a 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 pushing means for pressing the conveying member and the separating member. The sheet material sent out by the pickup means includes: a pressing force increasing / decreasing means for increasing / decreasing a pressure; 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 away from the sheet material. When the leading end of the sheet is detected by the detecting means, the moving means separates the pickup means from the sheet material stacked on the mounting table, and the pressing force increasing / decreasing means conveys the sheet. The pressing contact force between the member and the separating member is set high so that the sheet material is separated and fed, the sheet materials are separated one by one, and the rear end of the separated sheet material is detected by the detection means. Then, the pressing force increasing / decreasing unit is controlled so as to set the pressing contact force between the conveying member and the separating member to be low enough to allow the sheet material conveyed by the pickup unit to pass therethrough. Sheet material separating and feeding device.