JPH05186082A - Sheet material feeder - Google Patents

Abstract

(57) [Summary] [Purpose] Considering not only the thickness of the sheet material but also the rigidity,
The sheet material is properly fed by automatically adjusting the axial distance. [Structure] A sheet material P is sandwiched between a feeding roller 3 and a separating roller 31 and fed. The photointerrupter 1 measures the rotation speed of the feeding roller that varies depending on the thickness of the sheet material P and the like.
3 detects and the control means 16 controls the driving of the stepping motor 33 based on the signal from the photo interrupter 13. The stepping motor 33 is a separation roller 3
Lower 1 to the proper position and make the inter-axis distance proper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet material feeding device, and is suitable for use in an image forming apparatus such as a copying machine or a laser beam printer. The present invention relates to a mechanism for supplying a sheet material.

[0002]

2. Description of the Related Art Conventionally, various sheet material feeding devices have been proposed. FIG. 6 shows an example of a sheet material feeding device provided in the copying machine.

A copying machine equipped with this type of sheet material feeding device has an image forming section (not shown) inside.
In the image forming unit, a toner image is formed by a known means, and the toner image is transferred to the sheet material P fed by the sheet material feeding device 101.

In the sheet material feeding device 101, the mounting table 102 on which the sheet material P is placed is pushed up from below by a compression spring 105. The compression spring 10
5, the pickup roller 1 is attached to the main body 100 of the apparatus.
06 is provided, and the uppermost sheet material P ₁ on the mounting table 102 is configured to contact the pickup roller 106. When the pickup roller 106 rotates counterclockwise (in the direction of the arrow in the figure), the sheet material P ₁ is conveyed by the frictional force generated between the peripheral surface of the pickup roller 106 and the sheet material P. It is configured. On the other hand, in the sheet material advancing direction of the pickup roller 106 (the direction of arrow A in the figure), the feeding roller 1
07 and the separation roller 109 are arranged so as to face each other. The feeding roller 107 and the separating roller 108 are constantly driven to rotate in the direction of the arrow in the figure, and the feeding roller 107 is configured to convey the sheet material P along the guide plate 110 in the A direction. ing.

Further, the feeding roller 107 and the separating roller 10
The distance between the shaft and the shaft 9 can be manually changed by adjusting means (not shown).

[0006]

However, since the axial distance is manually changed in the sheet material feeding apparatus 101, the axial distance is reduced to feed the thin sheet material, and then the axial distance is reduced. If you forget to change the distance and try to feed thick sheet material, a paper feed error occurred. Similarly, if the distance between the shafts is increased and a thick sheet material is fed and then a thin sheet material is fed, a double feed occurs.

Further, the axial distance is adjusted by considering only the thickness of the sheet material P, and the surface property and rigidity of the sheet material P have not been considered so much. Therefore, the sheet material P
Depending on the rigidity of the sheet material, the sheet material P may or may not be fed, and it has been difficult to always feed the sheet material P in an appropriate state.

Further, considerable skill was required to adjust the axial distance in consideration of not only the thickness of the sheet material P but also the rigidity and the like.

Therefore, an object of the present invention is to provide a sheet material feeding device which can be operated by anyone and which is automatically set to an axial distance in consideration of not only the thickness of the sheet material but also the rigidity and surface property. It is a thing.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is provided with two rotatable rollers (3, 31) supported in a pair, and In the sheet feeding device (1) which feeds the sheet material (P) by rotationally driving at least one roller (3) of the two rollers (3, 31), the roller ( Detection means (13) for detecting the load of 3)
An adjusting means (33) for adjusting the axial distance between the two rollers (3, 31), and a controlling means (30) for driving and controlling the adjusting means (33) based on a signal from the detecting means (13). 16) and are provided.

In this case, each roller (3, 31) is
It may have large diameter portions and small diameter portions alternately, and the large diameter portion of one roller may be formed at a position not facing the large diameter portion of the other roller.

The detection means may be a rotation speed detection means (13) for detecting the rotation speed of the roller (3).

Further, the detecting means is a roller (3).
It may be current detection means (52) for detecting the current of the drive means (51) for driving the.

[0014]

[Function] Based on the above construction, the two rollers (3, 31)
At least one of the rollers is driven to rotate. Now
The sheet material (P) is fed between the rollers (3, 31) in a state in which the axial distance between the rollers (3, 31) is small and is not suitable for feeding the sheet material (P). And the sheet material (P) is rotated by the rollers (3, 3).
The rotation of (1) is hindered and a load is generated on the rollers (3, 31). Then, the detection means (13) detects the load on the rollers (3, 31) that are rotationally driven, and at the same time, sends a signal according to the load to the control means (16). Based on the signal, the control means (16) adjusts (3
3) is driven and controlled so that the axial distance between the rollers (3, 31) becomes an appropriate value. Therefore, the sheet material (P) is further fed in a proper state.

The reference numerals in the parentheses refer to the drawings and do not limit the structure in any way.

[0016]

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

FIG. 1 shows a sheet material feeding device 1 of a copying apparatus 100. 2 is a drawing of the sheet material feeding device 1 viewed from above, and FIG. 3 shows the torque limiter 7 shown in FIG. 2 in detail.

In the sheet material feeding device 1, the feeding roller assembly 2 has a feeding roller 3 at the center as shown in FIG. 2, and the feeding roller 3 has a large diameter portion and a small diameter portion. Have alternately. Shaft members 5a and 5b extend from both end surfaces of the feeding roller 3 via a one-way clutch 6, respectively. These shaft members 5a and 5b are rotatably supported by the main body of the apparatus.
A torque limiter 7 is attached to the end of the.

The torque limiter 7 has a spring reference plate 9, and the spring reference plate 9 has a circular shape. The spring reference plate 9 is fixed to the shaft member 5b.
A driven unit U ₁ is arranged closer to the shaft end than the shaft. As shown in detail in FIG. 3, the driven unit U ₁ has a base body 10 and a friction plate 11, and the base body 10 is a thick-walled cylindrical member fitted to the shaft member 5b. The base 10
On the basis of being engaged with the shaft member 5b via the pin 12, is configured to be movable in the axial direction of the shaft member 5b and not to rotate in the circumferential direction.

Further, a flange portion 10a is provided on the outer peripheral surface of the base body 10 so that a part of the base body 10 has a thin plate-shaped large diameter portion. A plurality of slits (not shown) are formed in the flange portion 10a at equal intervals in the circumferential direction, and a photo interrupter 13 is arranged near the end portion of the flange portion 10a (FIG. 2). The optical path of the photo interrupter 13 is blocked by the flange portion 10a, and the slit portion is configured to rotate integrally with the shaft member 5b so that light passes therethrough. A rotation speed detection means R for detecting the rotation speed is configured by detecting the frequency of the passing light. The rotation speed detected by the rotation speed detection means is converted into an electric signal,
The electric signal is input to the control means 16.

A friction plate 11 is attached to the shaft end side of the base body 10 described above. A compression spring 20 is interposed between the driven unit U ₁ having such a structure and the spring reference plate 9 so that the driven unit U ₁ is biased toward the shaft end. It is configured.

On the other hand, on the shaft end side of the driven unit U ₁ , there is provided a gear 17 which constitutes the drive unit U _2, and the gear 17 is arranged so as not to move in the axial direction and in the circumferential direction. It is supported by the shaft member 5b so as to be freely rotatable. The gear 17 is integrally formed with a disc 19 which comes into contact with the friction plate 11 of the driven unit U ₁ . The friction plate 11 is pressed against the disc 19 by the compression spring 20 to transmit the drive. The gear 17 is configured so that the drive from the motor 30 of the mounting body is transmitted via the idler gears 21 and 22, the gears 26 and 27 fixed to the pickup roller 23, the clutch 25, the belt 29, and the like.

On the other hand, a separating roller 31 having a large diameter portion and a small diameter portion is arranged below the feeding roller 3 (FIGS. 1 and 5), and the separating roller 31 has a large diameter portion. The feeding roller 3 is arranged so as not to face the large diameter portion (FIG. 5). The shaft member 31a of the separating roller 31 is rotatably supported by a supporting member 32 (FIG. 1), and the supporting member 32 is supported by a stepping motor (adjusting means) 33 so as to be movable up and down. It is configured to adjust the axial distance between the feeding roller 3 and the separating roller 31. Specifically, a so-called screw shaft (not shown) is coaxially attached to the output shaft of the stepping motor 33, and a screw nut (not shown) screwed to the screw shaft is attached to the support member 32. ) Is attached. When the stepping motor 33 is activated and the screw shaft is rotated by a predetermined angle, the support member 32 is moved up and down by a predetermined amount, and as a result, the axial distance is changed. There is.

A control means 16 is connected to the stepping motor 33, and the control means 16 is also connected to the rotational speed detection means R described above. Then, the control means 16 drives the stepping motor 33 to move the separation roller 31 to the uppermost position before the sheet material P is fed between the feeding roller 3 and the separation roller 31. While pushing up to a position to minimize the axial distance, while determining whether or not the axial distance is appropriate based on a signal from the rotation speed detection means R during feeding of the sheet material P, The stepping motor 33 is driven so that the distance between the shafts becomes appropriate, and the separation roller 31 is gradually lowered.

The pickup roller 23, the feeding roller 3 and the separation roller 31 are rotated counterclockwise. Further, the sheet cassette 35 for accommodating the sheet material P includes a mounting table 37 in the cassette container 36, and when the sheet material traveling direction (the direction of arrow A in the drawing) is set to the downstream side, the mounting table 37 is located on the downstream side downward. Is configured to be pushed up by the compression spring 29. Further, a guide 50 made of sheet metal or the like is provided downstream of the feeding roller 3. Furthermore, the adjustment of the inter-axis distance is performed when the sheet cassette 35 is mounted on the copying apparatus and the first sheet material P is fed.

Next, the operation of the above embodiment will be described.

An operator places a sheet material P of a predetermined size on the placing table 37 of the sheet cassette 35, and mounts the sheet cassette 35 on the copying apparatus 100. Then, since the mounting table 37 is biased upward by the compression spring 39, the uppermost sheet P ₁ of the mounted sheet material comes into contact with the outer peripheral surface of the pickup roller 23.

Next, when the operator presses a switch (not shown), the motor 30 and the clutch 25 are activated, and the driving force of the motor 30 is transmitted through the belt 29, the idler gear 22 and the like, and as a result, the pickup is performed. Roller 23, feeding roller assembly 2, and separation roller 3
1 is rotationally driven. Here, the driving force transmission in the feeding roller assembly 2 will be described in detail. First, the gear 17 attached to the shaft member 5b of the feeding roller assembly 2 receives the driving force from the motor 30. It is driven to rotate. As the gear 17 is driven to rotate, the disk 19 that constitutes the drive unit U ₂ of the torque limiter 7 also rotates integrally. A driven unit U ₁ is urged by a compression spring 20 on the disc 19.
Therefore, the driven unit U ₁ also rotates as the disk 19 rotates. When the driven unit U ₁ rotates, its driving force is transmitted to the shaft member 5b via the pin 12, and as a result, the feeding roller 3 rotates. Here, the transmission of the driving force from the disc 19 to the driven unit U ₁ is defined by the frictional force generated by the urging force of the compression spring 20, so that the driving force to the feeding roller 3 is not less than a certain level. Not transmitted.

When the pickup roller 23 is rotationally driven as described above, the sheet material P ₁ is fed along the guide plate 50, and its front end portion is the feeding roller of the feeding roller assembly 2. 3 and the separation roller 31 are inserted (FIG. 5). Since the axial distance between the feeding roller assembly 2 and the separating roller 31 is the minimum as described above, the fed sheet material P ₁ is driven by the rotational driving of these rollers 3, 31. Load. The driving force of the feeding roller 3 is made constant by the torque limiter 7, and the rotation speed of the feeding roller 3 is lowered by the load of the sheet material P ₁ (for example,
Rotation stops). Since the feeding roller 3 and the driven unit U ₁ rotate integrally, the driven unit U ₁
The rotational speed of the rotational speed detecting flange portion 10a attached to the vehicle also decreases.

On the other hand, the photo interrupter 13 detects the rotational speed of the flange portion 10a, and the control means 16
, A signal corresponding to the rotation speed is output. Based on such a signal, the control means 16 determines whether or not the feeding roller 3 is rotating at an appropriate rotation speed, and when it is not appropriate, sends a signal to the stepping motor 33,
The stepping motor 33 is driven. When the stepping motor 33 is driven, the screw shaft attached to the output shaft of the stepping motor 33 is driven to rotate, and the separation roller 31 is rotated.
Can be lowered. When the separation roller 31 is lowered in this way, the axial distance between the separation roller 31 and the feeding roller 3 increases, and the load of the sheet material P decreases. Then, the rotation speed of the feeding roller 3 increases. The control means 16
However, when it is determined that the rotation speed of the feeding roller 3 is proper, the driving of the stepping motor 33 is stopped, and as a result, the axial distance becomes proper. The sheet material P is fed in the proper state, and an image is formed on the sheet material P in the image forming unit inside the copying apparatus.

As a result, the axial distance between the feeding roller 3 and the separating roller 31 is automatically adjusted, so that the sheet material P is always kept in an appropriate state regardless of the thickness of the sheet material P. Can be delivered.

The influence of the rigidity of the sheet material P is also detected by the photointerrupter 13 as a change in the rotational speed, so that the sheet material P can be properly fed regardless of the rigidity.

Further, the adjustment of the distance between the axes is performed only for the sheet material P which is first fed among the sheet materials P stored in the sheet cassette 35, and the sheet materials which are fed thereafter. Since it is not performed for P, the loss of the feeding time of the sheet material P due to the adjustment of the interaxial distance can be minimized. This is particularly effective when the sheet materials P stored in the sheet cassette 35 have the same thickness, rigidity and the like.

When the sheet materials P having different thicknesses and rigidity are stored in the sheet cassette 35,
Of course, the inter-axis distance may be adjusted for each sheet.

Next, another embodiment will be described with reference to FIG. The same parts as those shown in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

A motor (driving means) 51 for rotationally driving the feeding roller 3 is coaxially attached to the end of the shaft member 5b, and the motor 51 is controlled so that the rotational speed is constant. Has been done. Further, a current detecting means 52 is connected to the motor 51, and the current detecting means 52 is connected.
Is configured to detect the load current of the motor 51 and output a signal corresponding to the load current to the control means 16.

Here, the load current of the motor 51 changes according to the load applied to the motor 51. The load applied to the motor 51 is the load applied to the feeding roller 3 by the sheet material P fed by the feeding roller 3. Therefore, the current detection means 52
Means to indirectly detect the load applied to the feeding roller 3 by the sheet material P.

On the other hand, the control means 16 is connected to the stepping motor described in the above embodiment,
When the control is started, the separation roller is held at an intermediate position, and then the stepping motor is rotationally driven according to a signal from the current detection means 52 to move the separation roller up and down.

Next, the operation of the above embodiment will be described.

When the pickup roller 23 is rotationally driven, the sheet material P is fed, and the front end portion of the sheet material P enters between the feeding roller 3 and the separating roller 31 of the feeding roller assembly 2.

Now, the sheet material P is these rollers 3,
When the sheet material P is thicker than the inter-axis distance of 31, the sheet material P becomes a load for rotationally driving the rollers 3, 31. The load is detected by the current detecting means 52, and the control means 1 is operated based on a signal from the current detecting means 52.
Reference numeral 6 lowers the separation roller by rotationally driving the stepping motor so that the signal becomes appropriate. The appropriate value of such a signal is determined based on the signal of the current detecting means 52 when the sheet material P is fed in an appropriate state.

Further, the sheet material P is the roller 3,
When the distance is smaller than the inter-axis distance of 31, the current detecting means 52 detects the decrease of the load torque, and the controlling means 16 rotationally drives the stepping motor so that the signal from the current detecting means 52 becomes appropriate. Then, the separating roller is raised.

As a result, the distance between the axes becomes proper, the sheet material P is fed in the proper state, and an image is formed in the image forming section inside the copying machine.

As a result, the axial distance between the feeding roller 3 and the separating roller 31 is automatically adjusted, so that the sheet material P is always kept in an appropriate state regardless of the thickness of the sheet material P. Can be delivered.

Further, the influence of the rigidity of the sheet material P is also detected by the photo interrupter 13 as a change in the rotational speed, so that the sheet material P can be properly fed regardless of the rigidity.

Further, the separation roller is made to stand by between the highest position and the lowest position to adjust the shaft distance, and the load is adjusted by using the current value. Can be shortened.

In the above embodiment, the motor 51
Is configured to directly drive the feeding roller 3,
It is not limited to this, and it may be indirectly driven via a gear, a belt or the like.

Further, although the present invention is applied to the paper feeding section of the copying machine in the above-mentioned embodiment, the present invention is not limited to this, and the present invention is applied to a paper feeding apparatus for feeding the sheet material from the outside such as a postcard feeder. Good.

Further, in the above-mentioned embodiment, the means for adjusting the axial distance is constructed by using the stepping motor, the gear and the like, but the invention is not limited to this, and the separating roller may be moved up and down by another method.

Furthermore, in the above embodiment, the standby position of the separation roller is set to the highest position or the intermediate position between the highest position and the lowest position, but the present invention is not limited to this, and any position may be used. ..

[0051]

As described above, according to the present invention,
Since the axial distance between the rollers is automatically adjusted, the sheet material can always be fed in an appropriate state regardless of the thickness of the sheet material.

Further, since the influence of the rigidity of the sheet material is also detected by the detecting means as the change of the rotation speed, the sheet material can be properly fed regardless of the rigidity.

[Brief description of drawings]

FIG. 1 is a side view showing a sheet material feeding device according to the present invention.

FIG. 2 is a view of the sheet material feeding device according to the present invention seen from above.

FIG. 3 is a partially enlarged view of a torque limiter 7.

FIG. 4 is a plan view showing a sheet material feeding device according to another embodiment.

FIG. 5 is a diagram showing a state in which a sheet material is sandwiched between a feeding roller and a separation roller.

FIG. 6 is a diagram showing a conventional sheet material feeding device.

[Explanation of symbols]

 1 sheet material feeding device 2 feeding roller assembly 3 roller (feeding roller) 7 torque limiter 13 detection means (photo interrupter) 16 control means 31 roller (separation roller) 33 adjusting means (stepping motor) 51 driving means (motor) 52 current detecting means 100 copying apparatus

Claims (4)

[Claims] 1. A rotatable member 2 supported so as to form a pair.
A sheet feeding device including two rollers and feeding a sheet material by rotationally driving at least one of the two rollers, a detection unit detecting a load of the rotationally driven rollers. A sheet material feeding device, comprising: an adjusting unit that adjusts an axial distance between the two rollers; and a control unit that drives and controls the adjusting unit based on a signal from the detecting unit. .. 2. Each of the rollers alternately has a large diameter portion and a small diameter portion, and the large diameter portion of one roller is formed at a position not facing the large diameter portion of the other roller. The sheet material feeding device according to claim 1, wherein: 3. The sheet material feeding device according to claim 1, wherein the detection unit is a rotation speed detection unit that detects the rotation speed of the roller. 4. The sheet material feeding device according to claim 1, wherein the detection unit is a current detection unit that detects a current of a drive unit that drives a roller.