JPH0466430A - Sheet feeding device - Google Patents

Abstract

PURPOSE:To ensure separative feed in an automatic manuscript feeding device by changing over a separating member having plural separate faces different in the coefficient of friction so as to selectively make an optional separate face opposite to a feeding member. CONSTITUTION:Separate faces 6a-6d having two or more different coefficient of friction mua=mud on the periphery of a base roller 6A are fixed to a separating member 6 which is oppositely brought into pressure contact with a feed rooler 2. The coefficient of friction of each of the separate faces is set within relation shown as follows, 6a>6b>6c>6d. A knob 39 is operated according to designation on its outside for the kind of a manuscript to give command to the separate face suited to the manuscript of the separate faces 6a-6d of the separating member 6. A separating member changing means 4 therefore moves a designated separate face to a position opposite to the feed roller 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial field of application The present invention is capable of separating sheets due to the difference in friction coefficient between a feeding member that feeds the sheet and a separating member that contacts this feeding member with a predetermined separating pressure. The present invention relates to a sheet feeding device that separates and conveys sheets, and specifically relates to a sheet feeding device that has a separation member having at least two separation surfaces with different coefficients of friction.

(B) Prior Art FIG. 18 shows an example of a conventional friction separation type sheet feeding device of this type.

In the figure, a notched circular call-out roller 12 fixed to a spindle 11 is disposed downstream of a sheet stacking table (original table) 10 on which a plurality of original sheets P are set. This calling roller 12 is connected to the lower guide plate 1.
The large diameter part extends from 3. The calling roller 12 has
The base is in pressure contact with a sheet holder 17 which is pivotally connected to an upper guide plate 16 by a shaft 15, and this sheet holder 17
A compression spring 19 is disposed between the upper guide plate 16 and the upper guide plate 16 to urge the sheet presser 17 toward the pick-up roller 12 side.

On the downstream side of the pick-up roller 12, a feeding roller 2 is arranged, which is fixed to a spindle 3 and rotates in the direction of an arrow 5 by an unillustrated drive source to feed the document P. Drive roller 20a and driven roller 2 rotating in the direction of the arrow
A pair of conveying rollers 20 consisting of rollers 0b are provided. The separation pad 21 whose free end is in contact with the feeding roller 2 and the base of the leaf spring on the lower surface thereof are fixed to a support member 23 provided on the main body cover 22. The base is supported by the shaft 25
The free end of the press plate 26, which is pivotally connected to the support shaft member 23, is in contact with the separation pad 21, and the press plate 2
Reference numeral 6 denotes a water holder that presses the separation pad 21 against the feeding roller 2 by the elasticity of a separation spring 29 consisting of a compression spring provided between a fixing member 27 provided on the main body cover 22 and a pressing plate 26, and a document P. The friction coefficient of the feeding roller 2 against the original document P is set to be larger than the friction coefficient between the original documents P, and the friction coefficient of the separation pad 21 against the feeding roller 2 is set to be smaller than the friction coefficient between the original documents P. When the calling roller 12, the feeding roller 2, the pair of conveying rollers 20, etc. are rotated with a plurality of documents P set on the sheet stacking table 10, most of the documents P are regulated by the sheet presser 17 and are moved to the lower side. The document P is conveyed to the feeding roller 2. The conveyed document P is transferred between the feeding roller 2 and the separation pad 2.
Due to the difference in friction coefficient between the two sheets, the sheets are separated one by one and fed, and further conveyed in the direction of arrow 30 by a pair of conveying rollers 20.

(C) Problems to be Solved by the Invention However, in the conventional sheet feeding device described above, the separation parameters 1 to 21 for separating the document P are selected and determined through repeated experiments, etc. Since it is made of a material with a high coefficient of friction, it is difficult for thin paper or thick paper to pass through it, so the paper is biased toward one side. Additionally, the range of types of sheets that can be fed is narrow overall, and some sheets may not be fed.

In particular, when a sheet feeding device is used as a document feeding device, there is no universal separation pad 21 for all types of documents, and there are many methods for selecting and testing the friction coefficient of the separation pad 21. required a lot of effort. Also,
The feeding performance of a sheet feeding device is greatly influenced by differences in the environment in which the sheet feeding device is used, and there are currently no conditions that satisfy all conditions. The area that received many complaints was the sheet feeding device that feeds sheets as original documents.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sheet feeding device in which a separation member having a plurality of separation surfaces with different coefficients of friction is provided, and sheets are separated by a separation surface suitable for the sheets being fed. That is.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances, and is illustrated with reference to, for example, FIGS. , a feeding member (2) that is driven in a direction to feed a plurality of sheets (P) one by one; and a feeding member (2) that cooperates with the feeding member (2) to separate the sheets (P). at least two different coefficients of friction (μa~μ
separation member (6) having the separation surfaces (6a to 6d) of d) and switching the arbitrary separation surfaces (6a to 6d) of the separation member (6) to a predetermined separation surface at a position facing the feeding section; A member changing means (4).

Further, when the sheet is fed by the feeding member (6), the separation member (6) is prevented from rotating in the sheet (P) feeding direction, but is allowed to rotate in the opposite direction. It has a member (43).

Further, it has a knob (39) that allows manual switching of the positions of the separation surfaces (6a to 6d) of the separation member (6).

Further, it is characterized in that it can be input by key operations on the keyboard (53), and the separation members (6a to 6d) are switched by the drive source (13) activated by the input.

Further, the separating member (6) acting on the feeding member (2)
It has separation pressure release means (60, 61) for releasing the separation pressures a to 6d) when switching the separation surfaces.

(E) Effect Based on the above configuration, when the feeding member (2) rotates with the sheet (P) inserted between the feeding member (2) and the separating member (6), the separating member (6) If the material (P) is separated, the paper is fed as is, and if the material (P) is not separated, the separating member (6) separates the sheet (P) using separation surfaces (6a to 6d) having other coefficients of friction (μa to μd). Attempt to separate P). Thereafter, similar operations are performed to separate the sheet (P) using the separation surface (6) having a friction coefficient suitable for the sheet (P) to be fed. As a result, sheets (P) of a wide range of paper qualities can be stably fed.

Note that the above-mentioned symbols in parentheses are shown for reference to the drawings, and do not limit the configuration of the present invention in any way.

(a) Example The following is an example of an automatic document feeding device as a sheet feeding device of the present invention. An example of lf (hereinafter referred to as ADF) will be described based on the drawings. Components having the same functions as those shown in FIG. 18 are denoted by the same reference numerals, and their explanation will be omitted.

1 and 2 show an apparatus (ADF) for feeding a document P in the form of a sheet. In the figure, a support shaft 3 to which a feeding roller (feeding member) 2 is fixed is pivotally supported by a pair of side plates 31 and 32 via bearings, respectively, as shown in FIG. A sheet conveyance motor 33 (see FIG. 13) as a drive source is attached to one end of the support shaft 3 (see FIG. 13).
Gear 35 connected to is fixed.

A separating member 6 fixed to a separating roller shaft 7 is in pressure contact with the feeding roller 2 as will be described later. They are each pivotally supported via. As shown in FIG. 3, the separating member 6 has at least two (four in this embodiment) different friction coefficients μ on the circumferential surface of the base roller 6A.
It consists of separated surfaces 68 to 6d having sizes a to μd fixed to each other. A pair of support members 34a fixed to the inner surfaces of the side plates 31 and 32 are each provided with a leaf spring 34b that presses the upper part of the separation roller shaft 7, and the elasticity of the leaf spring 34b causes the separation member 6 to be obtains separation pressure for the feed roller 2.

The respective friction coefficients μa to μd of the separation surfaces 6a to 6d are μa
〉μb〉μC〉μd, especially i! The friction coefficient μd after is the friction coefficient μp between the documents P.
The coefficient of friction is selected to be low so that μd≦μp. For example, a member such as Mylar is used as the separation surface 6d having a low coefficient of friction μd. This separation surface 6d is
It is not possible to separate double-fed documents P, and this method is particularly used when documents P are fed one by one manually.

Furthermore, if the friction coefficient of the feeding roller 2 with respect to the original P is μm, then μm>μa, and the above μC is μC>μp(
(friction coefficient between originals). The separating member 6 is rotated by a command means to be described later, and one of the separating surfaces 6a to 6d having a predetermined friction coefficient is selected and pressed against the feeding roller 2.

The end of the separation roller shaft 7 extending from the side plate 32 (
At the right end in the figure) is a position detection plate 36 (see Figure 9).
a gear 37 that is integrally formed with the , and a manual operation knob (command means) that rotates the separation member 6 as described later.
39 are fixed respectively. The above-mentioned arrow 30 is for detecting the separation surfaces 68 to 6d that are pressurized by the feeding roller 2. On the outer peripheral surface 39a of this knob 39,
As shown in FIG. 5, information corresponding to the friction coefficients of the separation surfaces 6a to 6d of the separation member 6 in pressure contact with the feeding roller 2 is written.

That is, characters 40a to 40d representing the types of documents P to be separated by the selected separation planes 68 to 6d are displayed on the display 40. Above characters 40a-4
0d corresponds to each of the separating surfaces 68 to 6d of the separating member 6. For example, when feeding a document P made of plain paper, the corresponding separating surface 6b or the feeding roller 0d corresponds to the separating surface 68 to 6d of the separating member 6. 2, and characters 40b are displayed on the display section 40.

The knob 39 can be rotated from the outside of a window 22a provided in the main body cover 22 as shown in FIG.
0d is visible from the display unit 40. moreover,
A plurality of click recesses 39b are formed in the circumferential surface 39a of the knob 39, as shown in FIG. By engaging the free end of the knob 42, the selectively rotated position of the knob 39 is held.

The opposite extending end of the separation roller shaft 7 is attached to a bearing 45 via a one-way rotation clutch 43, and this bearing 45 is attached to a support member 4 fixed to the side plate 31.
5 so that it can move up and down within an appropriate range. Due to the action of the one-way rotation clutch 43, the separating member 6 rotates only in the direction of arrow 9 in FIG. 1, and is prevented from rotating in the opposite direction. Note that when the separation member 6 rotates in the direction of the arrow 9, the separation surface 6a has a high friction coefficient, and the separation surfaces 6b, 6 have a gradually lower friction coefficient.
The separation surfaces 6a, 6b, 6c, and 6d are arranged so as to come into pressure contact with the feeding roller 2 in the order of e and 6d.

As shown in FIG. 2, a gear 49 is fixed to the end of the support shaft 11 to which the above-mentioned pick-up roller 12 is fixed.
(see Figure 3). As shown in FIG. 1, on the upstream side of the calling roller 12, a sheet presence/absence sensor 5 is provided for detecting the presence or absence of a document P on the sheet stacking table 10.
This sheet presence/absence sensor 5o is connected to a sensor lever 50a which is rotated by the document P and a sensor lever 50a which is rotated by the document P.
It consists of a photointerrupter 50b that turns on and off.

Further, on the downstream side of the feeding roller 2, a sensor lever 51a is provided.
A sheet feeding sensor 51 consisting of a photointerrupter 51b and a photointerrupter 51b is also provided. The sheet feeding sensor 51 detects the original P fed by the feeding roller 2, and determines whether the separation of the original P by the separating surfaces 6a to 6d currently in contact with each other has been properly performed. This detects whether the separation surfaces 68 to 6d being pressed are suitable for the document P being fed.

The separation surfaces 68 to 6d to be brought into pressure contact with the feeding roller 2 can be set by manually operating the knob 39 as described above, or this setting can also be done by using the keyboard shown in FIGS. 7 and 8. . In the figure, a keyboard for setting the separating surfaces 68 to 6d to be used is on the side of the printer (image forming device) to which the ADF (automatic document feeder) as a sheet feeding device is applied. 53 are arranged. As shown in FIG. 8, this keyboard 53 has operation buttons 56 (56a-6d) corresponding to each separation surface 68-6d.
56d) and a display section 57 that displays the operated items as characters 578 to 57d.

This display section 57 displays the set operation button 5.
6a to 56d may be illuminated, or the corresponding characters 57a to 57d on the display section 57 may be illuminated from the back side to make them visible. Furthermore, when the operation button 56 is operated, the status of the separation surfaces 68 to 6d may be displayed using the LCD display section 55 as shown in FIG.

When setting the separating surface using the keyboard 53, a driving force is required to drive the separating member 6 in response to the operated operation button 56, and this driving force is provided by the gear 37 (first gear) integrated with the separating member 6. Referring to FIG. 2, the rotation of the motor 59 is transmitted to the motor.

In addition, in order to detect the separation surfaces 6a to 6d that are in pressure contact with the feeding roller 2, a plurality of separation surface detection sensors 52 (52a to 52d) are arranged at predetermined positions as shown in FIG. 9(b). The separation surface detection sensor 52 is configured to be detected by a flag 36a provided on the position detection plate 36. The relationship between the positions of the separation surface detection sensors 52a to 52d and the separation surfaces 68 to 6d is shown in FIG. 9(b).
, are arranged correspondingly as shown in (C).

A command means 4 for setting the abutting position of the separating member 60 is also included as shown in the above-mentioned notch 39 and arrow 5 in FIG.

FIG. 11 shows a mechanism for changing the separation pressure of the separation member 6.

In the same figure (a), an eccentric cam 60 is fixed to the separation roller shaft 7 which is integrated with the separation member 6.
A pressure member 61 is in pressure contact with the upper part of 0 by the elasticity of a tension spring whose one end is locked to a bottle 63. This pressure member 61 is pivotally supported by a support shaft 62, and its upper end is connected to a solenoid 67 via a connecting member 66.

When the solenoid 67 is in the OFF state, the separating member 6 is in pressure contact with the feeding roller 2 due to the separating pressure due to the elasticity of the bow tension spring 65, and the rotation of the separating member 6 causes the separating surfaces 68 to 6 to be pressed against each other.
When d is switched as described later, the separation pressure against the feed roller 2 is also changed by the action of the eccentric cam 60.

When changing the separation surfaces 68 to 6d of the separation member 6,
Since separation pressure is applied to both the separation member 6 and the feeding roller 2, the solenoid 67 is operated to reduce the separation pressure when switching the separation surfaces 68 to 6d so as not to put a load on the driving means such as a motor. is released to facilitate rotation of the separating member 6.

Alternatively, as shown in FIG. 11(b), an Archimedes cam 71 may be provided on the separation roller shaft 7, and a roller 61a provided on the pressure member 61 may be brought into pressure contact with the Archimedes cam 71 to change the separation pressure. Since the elasticity of the tension spring 65 changes as the Archimedes cam 71 rotates together with the separation member 6, the separation pressure of the separation member 6 changes in response to the rotational position of the separation member 6, that is, the switching of the pressure contact of the separation surfaces 68 to 6d. or changed.

The above-mentioned position detection plate 36, one-way rotation clutch 43, sheet feeding sensor 51, separation surface detection sensor 52 and timer 69, CPtJ70 (see FIG. 13) use the shade to control the road separation surface of the separation member 6 by the command means 4. Separation member changing means 4 for switching 68 to 6d to predetermined separation surfaces is mounted together.

Next, the operation of the automatic document feeder configured as described above will be explained with reference to the flowcharts shown in each of the above-mentioned figures, FIGS. 14 and 15. In addition, Figure 14 is the manuscript P.
FIG. 15 shows flowcharts for cases in which documents P are loaded in the same type or in a mixed manner.

First, the same type loading mode will be explained. When a plurality of documents P are placed on the sheet stacking table 10 and inserted, the sheet presence/absence sensor 50 detects this. If you perform the start operation here, the sea 1 to transport motor 3 shown in Fig.
3 rotates, and the calling roller 12, feed roller 2, conveyance roller pair 20, etc. start rotating, and one of the originals P is rotated.
The sheet or a plurality of sheets taken out are fed to the feeding roller 2.

Before separating the documents P, the separation member 6 is normally in a state in which the separation surface 6a having the largest coefficient of friction is in pressure contact with the feeding roller 2 (Sl), and the state in which the separation surface 6a is in pressure contact is returned to the original position. (home position). Among the documents P being fed, there are some documents P that are suitable for separation by the separation surface 6a having a large coefficient of friction, such as thin documents that are difficult to separate and feed.
Next are normal manuscripts, thick manuscripts, etc.

Referring to FIG. 10, the separation operation of the original P will be explained. The document P located between the feeding roller 2 and the separating member 6 is separated by the feeding roller 2 and the separating member 6, which rotate in the directions of the arrows, respectively, in response to a paper feeding command by operating the start button, and the rotational speed of the feeding roller 2 increases. Move at the same speed as the arrow 3, but if there is a slip, move at a speed slightly slower than the rotation speed.
When the sheet moves in the 0 direction and is detected by the sheet feeding sensor 51 and is further conveyed by the pair of conveying rollers 20, the rotation of the feeding roller 2 is stopped.

Here, whether the document P that is being fed by slipping or the feed roller 2
The sheet feeding sensor 51 is inserted from the pressure contact position between the separating member 6 and the separating member 6.
sensor lever 51. Assuming that t is the time it takes to reach time a, a document P that takes longer than that is not suitable for separation by the separation surface 6a of the separation member 6 that is in pressure contact with the feeding roller 2.

In this case, paper feeding is temporarily stopped, and the separation member 6 is rotated in the direction of arrow 9 by the motor 59, and this rotation is stopped by detection by the separation surface detection sensor 52. Here,
The same separation action is repeated by rotating the feeding roller 2 again. In this way, by sequentially changing the separation surfaces 6a to 6d, if the document P is fed, it is OK, or if the document P is not fed, a warning (alarm sound, lamp lighting) is issued and the LCD display 57 etc. will be displayed.

As described above, when the separation surfaces 68 to 6d are automatically switched and set using the time t as a parameter and paper feeding is finished, the separation member 6 must be returned to its original position.

The above operation will be explained with reference to FIG. 14. As the feeding roller 2 rotates, an attempt is made to separate the document P on the separation surface 6a (a side) of the separation member 6 (S2), and the document P is separated. If so, the process continues as it is and the paper is fed up to 5IO) and the process ends (Sll).

If the separation by the separation surface 6a is not performed in (S2), the separation member 6 rotates due to the rotation of the sheet conveyance motor 33, and the separation surface 6b comes into pressure contact with the feeding roller 2 (S3). This state is detected by the separation surface detection sensor 52b in FIG. 9(b), the separation member 6 is stopped, and the display is displayed on the display section 57 or the display section 55 or the like.

If the document P is separated by the separation surface 6b in (S4), the process continues to feed paper until it runs out of paper (5IO), and ends when it runs out of paper (Sll). (S4
), the separating member 6 is rotated in the same manner as described above (S2), and the next separating surface 6C comes into pressure contact with the feeding roller 2 (S5), and the document P is separated by the separating surface 6C (S6). ). If separation can be performed, the paper is fed without any paper.

If separation is not possible in the above (S6), in this case, the separation member 6 will not automatically rotate and the paper feed will stop (S7).
). This non-separable state is indicated by an alarm or the like, and when displayed on the display section 55 (see FIG. 5), characters 55d1 are displayed. In this state, the operator operates the single-sheet document operation button 56d (see FIG. 8), whereby the separating member 6 rotates and presses the separating surface 6d against the feeding roller 2 (S8). The single document mode is displayed on the LCD as characters 55d, as shown in FIG. 6(d).

Here, the single-sheet mode refers to a part of the separation member 6 (separation surface 6
d) is made of a material with a low coefficient of friction such as Teflon, and means that one document P can be fed without fail. The single-sheet mode is a mode that is facilitated when the original P is not fed even after changing the friction surface (separation surface) of the separation member 6, and is set at the end of switching between the separation surfaces 6a to 6d. It is the mole that follows. As mentioned above, the separation surfaces 6a to 6d are switched by sequentially arranging and rotating them from the side with the largest coefficient of friction to the one with the smallest coefficient of friction, and it is possible to feed paper by automatically performing this switching. It has become.

In this single-sheet mode state, the document P is inserted and fed one by one into the feeding roller 2 by the operator's manual operation (S9).
During this manual paper feeding, the friction coefficient μd between the separating surface 6d and the document ■ is set to be smaller than the friction coefficient μp between the documents P, so when multiple documents P are inserted into the cage, Then, the documents P are fed in duplicate. In other words, the separation surface 6d is set to have a coefficient of friction small enough to allow manual paper feeding, making it easy to feed one sheet at a time.

Furthermore, since the document P used is generally plain paper in many cases, the separation member 6 In the separation process, the separation surface 6a is omitted and the separation action is started using the separation surface 6b (six surfaces), thereby saving work time.

Next, the document P is separated using each of the ten separation members 6 (81
1) When the process is finished, it is checked whether or not there are any keys on the keyboard 53 (S12). If there is key human power, the separation member 6 returns to its original position (home position) and starts separation operation from (Sl) by the separation surface 6a. (
In S12), if there is a key input, it is checked whether the input is from the separation plane 6b (plane 6). If the input is 6 sides, the process returns to (S3) and the separation of the original P by the separation surface 6b is started, and if the input is not 6 sides, the process returns to (S5) and the separation of the original P by the separation surface 6c is started. .

FIG. 15 shows a flowchart of a so-called mixed loading mode in which each document P has a different property. In this figure, the sequential switching of the separation surfaces 68 to 6d when the document P cannot be separated at the start of paper feeding is the same as the same type loading mode in FIG. 13, and therefore the explanation thereof will be omitted.

The difference between this mixed loading mode and the same type loading mode described above is that the originals are
If separation is performed, one sheet of document P is fed (S1
4), the presence or absence of the document P is checked (S15) and the settings are changed. If there is a document P in (S15), it always returns to the original position (Sl), repeats the same process again, and then feeds only one sheet. When the document P continues to be fed and the document P runs out (Sll), the process ends, and the separating member 6 returns to its original position and stops.

By feeding the original P in this way, the original P
Sheet loading table 10 with a mix of paper types or different types
Even if the document P is set to 1, the setting of the separation member 6 of the ADF is changed accordingly, so documents P having different properties or a mixture can be set with confidence.

In the case of feeding the above-mentioned mixed documents P, operate the operation button 56 of the keyboard 53 shown in FIG.
It is also possible to predetermine the initial position of , and in this case, the separation member 6 returns to its original position at the separation plane position set as indicated by L. As a result, when feeding paper, the separating action of the separating member 6 does not have to start from thin paper, but can also start from plain paper original I) or thick paper original P, without skipping the previous stage. This allows you to feed paper more efficiently.

Furthermore, when the paper quality of the original P changes and the separation surface of the separation member 6 is changed as described above, the separation pressure switching means as explained in FIG. 11 is used to adjust the separation pressure suitable for the separation surface used. It is also possible to change them at the same time.

FIGS. 16 and 17 show the second sheet feeding surface of the present invention.
An example of this is shown.

In this embodiment, instead of the rotatable separation member 6 in the above-described embodiment, a plurality of pressure members 72 and separation pads 80a to 80 with different friction coefficients are provided on the pressure members 72, respectively.
0c is used.

In the figure, a plurality of V-shaped pressure members 72 whose bases are pivotally supported on a support shaft 73 are biased clockwise in the figure by tension springs each having one end latched to a shaft 79. . The lower edge of the upper arm of each pressure member 72 is connected to a plurality of eccentric cams 7 each fixed to a cam 76.
5a to 75c, respectively. Each pressure member 72
Separation pads 80a to 80 are selectively or combined with the circumferential surface of the feeding roller 2 and press-contact and spaced apart from each other by +n.
c or each is fixed. Also in this example,
The command means for press-contacting the separation pads 80a to 80c is the same as in the previous embodiment, and the conversion means for switching the pressure-contact and separation pads is driven by a motor 59 connected to the camshaft 76, so that one or several separation pads can be connected to each other. 80 (80
A to 80c) are brought into contact with or separated from the feeding roller 2 in descending order of friction coefficient, and documents P of a wide range of paper qualities are fed.

(g) As described in detail, according to the present invention, a separating member for separating sheets is provided with a plurality of separating surfaces having different coefficients of friction, so that separation is performed in accordance with the paper quality of the sheets to be fed. Since the sheet materials are separated by surface, it is possible to support the feeding of various types of sheets. In particular, sheets that were originally thought to be difficult to feed can now be fed through the separation member.
The number of types of paper that can be fed is greatly increased, and a highly reliable sheet feeding device that can stably feed paper can be realized.

[Brief explanation of drawings]

FIG. 1 is a vertical side view of a sheet feeding device in which an embodiment of the present invention is applied to an automatic document feeding device, FIG. 2 is a developed plan view of the same, and FIG. 3(a) is a vertical side view of a separation member. , Figure 3 (
b) is a front view, FIG. 3(c) is a developed view showing another example of the separating member, FIG. 4(a) is a longitudinal cross-sectional side view of the manual knob part, and FIG. 4(b) is a front view. Similarly, FIG. 5 is a plan view showing the display section 40 provided on the knob, FIG. 6 is a plan view of the display section during keyboard operation, and FIG. 7 is an image forming apparatus to which the present invention is applied and its keyboard. 8 is an enlarged plan view of the keyboard, FIG. 9(a) is a position detection plate and a vertical cross-sectional side view of the position detection plate, FIG. 9(b) is a front view, and FIG. 9(c) is a plan view of the keyboard. 10 is a diagram of the positional relationship of the dispensing member with respect to the separation surface detection sensor, FIG. 10 is an operational view of the device in FIG. 1, FIG. b) is a side view showing another example of the separation pressure release mechanism; FIG. 12 is a timing chart of rotation of the paper feed roller and sheet detection after paper feeding; FIG. 13 is a block diagram of the control unit of the present invention; FIG. 14 is a flowchart when sheets are simultaneously loaded, FIG. 15 is a flowchart when sheets are mixedly loaded, FIG. 16 is a longitudinal cross-sectional side view of a sheet feeding device showing a second embodiment of the present invention, and FIG. The figure is also a developed plan view, No. 18
The figure is a longitudinal side view showing an example of a conventional sheet feeding device. P... Sheet (original), t... Time from the start of sheet feeding until it is detected 2... Feeding roller (
feeding member), 4... separation member changing means, 6...
Separation member, 6a to 6d...Separation surface 33...Sheet conveyance motor 37...Gear 39...Knob
39.53... Command means 40... Display section 40
a to 40d...Display characters, 43...One-way rotation clutch (clutch member), 50...Seat presence/absence sensor
, 51...Sheet feeding sensor 52...Separation surface detection sensor 53...Keyboard 55a-5
5d...Display characters 56...Operation buttons
57a to 57d...Display characters 59...Motor 60.61...Separation pressure release means, 70...CP [
J, 72... Pressure member (separation member) 758-7
5C...cam, 80a-80c...separation bat.

Claims (1)

[Scope of Claims] 1. A feeding member that is driven in a direction to feed a plurality of sheets one by one, and at least two parts that cooperate with the feeding member to separate the sheets. A sheet feeding device comprising: a separation member having separation surfaces with different coefficients of friction; and separation member changing means for switching an arbitrary separation surface of the separation member to a position facing the feeding member. . 2. A clutch member that prevents the separating member from rotating in the sheet feeding direction and allows it to rotate in the opposite direction when the feeding member feeds the sheet. Item 1. The sheet feeding device according to item 1. 3. The sheet feeding device according to claim 1, further comprising a knob that allows manual switching of the position of the separating surface of the separating member. 4. The sheet feeding device according to claim 1, wherein input is possible through key operations on a keyboard, and the separation member is switched by a drive source activated by the input. 5. The sheet feeding apparatus according to claim 1, further comprising separation pressure release means for releasing the separation pressure of the separation member acting on the feeding member when switching the separation surface.