JPH01313223A - Automatic paper feeder - Google Patents

Abstract

PURPOSE:To obtain an automatic paper feeder capable of corresponding to papers having a wide thickness range by providing in the first place a level detecting sensor for detecting the level affording a rotation instruction to a paper feed roller. CONSTITUTION:In the case of thick paper, as a paper feed roller 6 receives a strong resistance from a resistance member 9 due to the strong nerve of the paper in the initial paper feed level in which the gap L between the contact position A of the paper feed roller 6 and the impact position B of the resistance member is short, the slipping of the paper feed roller 6 on the upper surface is caused, and no paper feed is conducted. When the paper feed is not conducted, no detection signal is outputted from a paper detecting sensor 10, so that a paper table 1 is raised in a determined amount, or a supporting member 5 is lowered in a determined amount. By this motion, the gap L between the contact position A and the impact position B is widened to make the paper easily caught between the both A and B. The paper feed roller 6 rotates to try the paper feed again. When the paper feed is not conducted, neverthless, the above motion is again repeated to widen the gap L until the paper can be fed out.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a device for automatically feeding stacked sheets one by one, which includes a paper feed roller that feeds the sheets by friction drive and a feed roller that feeds the sheets one by one. The present invention relates to an automatic paper feeder equipped with a resistance member that separates paper sheets by frictional load or locking load.

(Prior art) A paper feed roller is rotated in contact with the top surface of the stacked sheets to apply a feeding force to the top surface of the stacked sheets, and the multiple sheets of paper that are about to be fed by the paper feed roller are rotated diagonally to the bottom surface of the paper. An automatic sheet feeder is known that has a structure in which a separating pad is arranged so as to collide with the leading edge of the sheet, and a locking claw locks the leading edge of the sheet to separate the sheets and allow only one sheet to pass through. FIG. 5 shows an example of a conventional separation pad type automatic paper feeder, in which 1 is a paper table supported by a guide (not shown) so that it can be raised and lowered, 2 is paper stacked on the paper table, and 3 Reference numeral 4 indicates a guide plate that guides the leading edge of the stacked paper 2; 4, a support arm pivotally connected to a stationary member through a support shaft 5; and 6, a paper feeder that is pivotally connected to the end of the support arm and driven in the direction of the arrow shown in the figure. 7 is a level detection sensor that detects the paper feed level based on the swing angle of the support arm 4; 8 is a stopper that regulates the downward movement angle of the support arm 4; 9 is a level detection sensor that detects the paper feed level by the swing angle of the support arm 4; a separation pad for separating the paper by applying frictional resistance to the tip; 10 a paper detection sensor for detecting the paper that has passed over the separation pad;
Reference numeral 11 indicates a rank fixed to the paper table l, and 12 indicates a pulse motor equipped with a pinion 13 that meshes with the rank.

In the conventional device, paper is fed at a constant level regardless of the paper thickness of the stacked paper 2, and the contact position A between the paper feed roller 6 and the top surface of the stacked paper 2 and the separation from the leading edge of the paper to be fed out. The collision position B with the pad 9 is constant, and the distance between the contact position A and the collision position B is also constant.

(Problem to be solved by the invention) There is a demand for automatic paper feeding devices, especially automatic paper feeding devices attached to printers and readers of office computers and personal computers, to automatically feed all kinds of paper with one device. Extremely strong. For example, even one sheet of paper weighs 45 kg/
It is required to be able to automatically feed a wide variety of paper types, from paper equivalent to reams of paper to thick paper equivalent to 220 kg/kg, without any problems.

However, paper has different rigidity (strength) depending on its thickness. For example, cardboard has a high bending strength, so when it collides with the separation pad 9, it cannot bend smoothly and digs into the pad surface, which tends to cause problems such as pink errors, that is, the paper is not fed out. Pick mistakes can be avoided by increasing the contact force between the paper feed roller 6 and the paper, or by moving the contact position away from the separation pad 9, but if this is done, double feeding is likely to occur when thin paper is fed. This problem occurs, and there is a limit to the range of paper thickness that can be automatically fed. There is a way to solve the above problem by adjusting the contact force between the paper feed roller 6 and the stacked paper 2 according to the type of paper, but this requires adjustment of the device every time the paper thickness changes, making operation difficult. Control becomes troublesome.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an automatic sheet feeding device that has a front wheel structure and can handle sheets of a wider thickness range without requiring any adjustment or fabrication.

(Means for Solving the Problems) In the present invention, the above problems are solved by adopting a control structure that makes the interval between the contact position A and the collision position B variable and automatically sets the interval. ing. That is, in the automatic paper feeder of the present invention, as the paper table 1 rises or the support member 5 of the paper feed roller 6 descends when attempting to feed paper, the upper surface of the stacked paper 2 and the paper feed roller 6 are Contact position A
and/or collision position B between the resistance member 9.9a and the leading edge of the paper
A level detection sensor 7 is provided to detect the level at which a rotation command is given to the paper feed roller 6 for the first time, and the first rotation command is given to the paper feed roller 6 at this level. If the paper detection sensor 10 does not output a detection signal after the paper feed roller 6 has rotated, the paper tray 1 is further raised by a predetermined amount or the support member 5 is lowered by a predetermined amount to rotate the paper feed roller 6. It uses a control structure that repeats operations.

(Function) In the above structure, the level at which the paper feed roller 6 is initially rotated is set based on the feeding of thin paper, and the thin paper is sent out at the initial paper feeding level. When the paper is thick paper, at the first paper feeding level where the distance between the contact position A of the paper feed roller and the collision position B of the resistance member is short, the stiffness of the paper causes the resistance member 9.9a to Due to strong resistance,
The paper feed roller 6 slips on the upper surface of the paper and paper cannot be fed. If paper is not fed, no detection signal is output from the paper detection sensor 10, so the paper table 1 is raised by a predetermined amount or the support member 5 is lowered by a predetermined amount. This operation widens the distance between the abutting position A and the collision position B, and the paper becomes easier to bend between them. Then, the paper feed roller 6 rotates again and attempts to feed the paper. If the paper is still not fed out, the above-mentioned operation is further repeated to increase the interval until the paper is fed out. That is, in the apparatus of the present invention, the distance between the contact position of the paper feed roller 6 and the collision position B of the resistance member 9.9a is automatically set according to the thickness of the paper, which prevents picking errors and double feeding from occurring. It is possible to automatically feed a wide variety of paper types with different thicknesses.

(Embodiment) Figures 1 to 3 show an embodiment of the present invention, and show an example in which the invention is implemented in a separation pad type automatic paper feeder having a structure similar to that shown in Figure 5 above. It is something that

In FIGS. 2 and 3, the same reference numerals as in FIG. 5 are given to the members explained in FIG. 5, and the parts that differ from the structure in FIG. There are only 7 mounting structures.

The tip of the support arm 4 is an arcuate surface centered on the support shaft 5, and the level detection sensor 7 is operated by coming into contact with this arcuate surface. With this structure, even if the support arm 4 further moves upward after the level detection sensor 7 detects the support arm 4, the detection signal can be maintained without damaging the sensor 7. Further, in this structure, when the support arm 4 swings greatly and rotates above the sensor 7, the sensor 7 is turned off, and in the control shown in FIG. 1, this off signal is used as an abnormal stop signal.

In the standby state, the paper table 1 is in the lowered position, the lowering of the support arm 4 is stopped by the stopper 8, and the upper surface of the stacked paper 2 and the circumferential surface of the paper feed roller 6 are slightly apart.

Now, in FIG. 1, when a paper feed command is given from the main unit, a lift command is given to the paper table l, the upper surface of the stacked paper 2 comes into contact with the paper feed roller 6, and the support arm 4 is pushed up.
The paper table 1 is raised until the level detection sensor 7 is turned ON, and the upper surface of the stacked paper 2 is set to the initial paper feeding level. Immediately after giving a timing start command to the timer in step 21, the paper feed roller 6 is rotated in step 22. The state at this time is shown in FIG. 2, and the position B where the leading edge of the paper to be sent out collides with the separation pad 9 is from the contact position A of the paper feed roller 6 to the top surface of the stacked paper 2. Interval L
Only 1 apart.

If the paper detection sensor 10 detects paper before the end of the timer is detected in step 24, it is assumed that the paper has been fed normally, and the paper feed roller 6 is In order to avoid a feeding load, the paper table 1 is lowered to separate the paper feed roller 6 from the paper surface, and the next process such as printing operation is started.

If the timer counts up before the feeding of the paper is detected in step 23, it is assumed that the separation pad 9 is preventing the paper from feeding due to the stiffness of the paper, and the paper tray 1 is removed in step 25. Increase by a predetermined amount.

This operation is performed by applying a preset amount of drive pulses in the upward direction to the pulse motor 12. The control then returns from step 26 to before step 21, restarts the timer, rotates the paper feed roller 6, and tries to feed the paper again. When the paper table l is further raised from the initial paper feeding level, as shown in Fig. 3,
The leading edge of the paper that is about to be sent out collides with the separation pad 9 at a higher position, and the plate pad 9 is tilted so that the direction in which the paper is sent out is higher, so that the paper does not collide with the separation pad. Position B is separated from position A where the paper feed roller contacts the paper, and due to the support structure of the paper feed roller 6, contact position A also moves slightly in the separating direction, and the distance between both A and B is L2.
is the initial spacing, which becomes wider. Therefore, the paper that is about to be sent out is more likely to bend between the two A and B, and even thick paper can easily pass through.

Then, the operations from step 21 to step 26 are repeated until the paper detection sensor 10 detects the passing paper, so that the paper is separated and sent out when the gap becomes an amount appropriate for the paper thickness. Therefore, 1, the spacing is not excessively wide relative to the paper thickness, so double feeding does not occur.

If the level detection sensor 7 comes off the tip of the support arm 4 due to repeated upward movements of the paper tray l and turns off again, it is assumed that some abnormality has occurred and paper feeding is not performed.
In step 27, the device is abnormally stopped.

The above explanation is for a separation pad type device, but even with a locking claw type automatic paper feeder, the support arm 4 will move in the opposite direction due to the upward movement of the paper table 1, as shown in Fig. 4. The locking claw 9a swings in the direction to lock the contact position A of the paper feed roller 6.
The structure can be such that the distance between A and B is widened by separating them from the collision position B. The wider the interval, the more easily the paper flexes within the interval, and the more easily it becomes detached from the locking claw 9a, so it is possible to automatically feed sheets of different thickness using the same control as described above.

Furthermore, although the above embodiment has a structure in which the gap 17 is widened by raising the paper table l, in both the structure shown in FIG. 2.3 and the structure shown in FIG. Since the above effect is achieved by moving the roller upward relative to the support shaft 5, the apparatus of the present invention can also be realized with a structure in which the paper table 1 is fixed and the support shaft 5 is lowered.

(Effects of the Invention) According to the device of the present invention described above, it is possible to suppress both the occurrence of double feed when feeding thin paper and the occurrence of pick mistakes when feeding thick paper, and it is possible to smoothly feed a wider variety of paper types. Moreover, the optimal paper feeding conditions are automatically set according to the properties of the paper, so there is no need to increase the operator's work burden, the device structure is simple, and the device cost is 1- It has the excellent effect of not increasing the

[Brief explanation of the drawing]

Figures 1 to 3 are diagrams showing one embodiment of the present invention,
FIG. 1 is a control flowchart, FIG. 2 is a side view of the main parts showing the initial paper feeding level, and FIG. 3 is a side view of the main parts showing the paper feeding level when the paper is thick. FIG. 4 is a side view of the main part showing an embodiment in which a locking pawl is used as a resistance member;
FIG. 5 is a side view of the main parts of a conventional device corresponding to the structure shown in FIGS. 2 and 3. In the figure, 1: Paper table 2: Loaded paper 5: Support shaft
6: Paper feed roller 7: Level detection sensor 9
: Separation pad 9a: Locking claw lO: Paper detection sensor A: Contact position between paper feed roller and paper B: Collision position between resistance member and paper L: Distance between positions A and B

Claims (1)

[Claims] A paper feed roller (6) that rotates in contact with the upper surface of the stacked paper (2) on the paper tray (1), a resistance member (9, 9a) for separating the paper sent out by the roller, and the resistance member In an automatic paper feeder equipped with a paper detection sensor (10) for detecting paper sent beyond a member, the contact position (A) between the paper feed roller (6) and the top surface of the stacked paper (2) and the leading edge of the paper that is about to be sent out and the resistance member (9, 9a
), the collision position (B) with the paper tray (1) changes between the two positions (A) and (B) as the paper tray (1) rises relative to the paper table (1) when the paper feeding operation is performed.
The paper feed roller (6) or the resistance members (9, 9) are installed in a structure in which the interval (L) is widened, and the level for first detecting the level at which a rotation command is given to the paper feed roller (6) is A detection sensor (7) is provided, and a paper feed roller (6) is provided.
) is rotated and the paper detection sensor (10) does not output a detection signal, the operation of further relatively raising the paper table (1) by a predetermined amount and then rotating the paper feed roller (6) is repeated. An automatic paper feeder characterized by: