JPH05238576A - Pad pressure adjusting device for paper feed cassette - Google Patents

Abstract

PURPOSE:To adjust a pad pressure to a proper value within a double feed- preventing range by providing a sensor for detecting the pad pressure in the case that a friction pad is brought into contact with the peripheral surface of a friction roller through paper. CONSTITUTION:A detecting sensor 13 of a pad pressure is provided between a friction pad 6 and a manually-operated moving member 8. In the case of wearing the friction pad 6, by a degree of corresponding to this wearing amount, a spring 12 is placed in an extended condition to decrease the pad pressure. On the other hand, since a space between a supporting member 10 and a screw 8 is spread, an indicating value of a tension gage 13 is changed to detect decrease of the pad pressure. In the case of decreasing the pad pressure displaced from a double feed-preventing range, the screw 8 is turned by hand and moved to a side of a friction roller 4, and the pad pressure is returned to a proper value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pad pressure adjusting device for a paper feed cassette having a friction pad for accommodating paper and feeding the paper.

[0002]

2. Description of the Related Art Conventionally, in copying machines and printers, various systems have been adopted in order to prevent double feeding of sheets fed from a set sheet feeding cassette. There are a friction roller separation method and a friction pad separation method.

First, the principle of the friction roller separation system will be described with reference to FIG. The figure shows a direction in which two sheets of paper 3 are sandwiched between a pair of friction rollers 1 and 2 facing each other, and the friction rollers 1 and 2 bring their outer peripheral surfaces into contact with each other by a biasing force "P". The state is being biased to. A paper feed cassette (not shown) is set on the right side of the drawing, and the left direction in the drawing is the paper feeding direction.

Here, the coefficient of friction between the one friction roller 1 and the sheet 3 is "μ _A ", the coefficient of friction between the sheets 3 is "μ _P ", and the other friction roller 2 and the sheet 3 are When the friction coefficient between them is “μ _B ”, the frictional force “F _A ” which acts between the friction roller 1 and the sheet 3, the frictional force “F _P ” which acts between the sheets 3 and the friction roller 2 frictional force "F _B" that acts between the sheet 3 and, _{respectively, F a = μ a P,} F P = μ P
P, F _B = μ _B P.

Further, in the paper feeding in this state, the conditional expression for preventing the double feeding is │F _A │> │F _B │ >> │F _P │ + α. Note that “α” is the frictional force “F” due to the weight “M” of the paper 3.
_M ″ (F _M = _M μ _P ), which varies depending on the number of sheets of paper 3 sandwiched between the friction rollers 1 and 2. The above conditional expression is satisfied and the influence of “α” is exerted. For complete removal, the relation of “μ _A > μ _B >> μ _P ” is required, but the friction coefficient “μ” is almost 0 μ.
The range of 1 to 1 and the difference of each force (| F
_{A │-│F B} │, in order to increase the │F _B │-│F _P │ etc.), it is necessary to increase the biasing force "P". On the other hand, if the urging force "P" is made too large, the frictional state between the members changes, and the relation of the above conditional expression cannot be established. Therefore, the urging force "P" has a double feed prevention range that does not cause double feed. In the friction roller separation system shown in FIG. 11, the two friction rollers 1 and 2 are rotated in the same direction to positively move the frictional force “F _A ” in the sheet feeding direction and the return direction. because you are giving a friction force "F _B", biasing force "P" is sent somewhat heavy even if the change is less likely to occur. However, a power transmission mechanism for transmitting the driving force to the two friction rollers 1 and 2 and a holding mechanism for holding the friction roller 2 so that the friction roller 2 can move toward and away from the friction roller 1 are required. Therefore, the number of parts is increased, the structure is complicated, and the cost is increased.

Next, the principle of the friction pad separation system will be described with reference to FIG. This friction pad separation method is used for the main body of a copying machine or the like (not shown).
And a friction pad 6 that is attached to a paper feed cassette 5 that stores the paper 3 and that is elastically abutted on the outer peripheral surface of the friction roller 4 via the paper 3. It is a component. Here, the mounting structure of the friction pad 6 to the paper feed cassette 5 will be described in detail. A base 7 is fixed to the paper feed cassette 5, and a screw 8 is screwed to the base 7. A hole 9 is formed at the center of the screw 8, and a leg 11 fixed to a support member 10 that supports the friction pad 6 is slidably fitted in the hole 9. Further, the upper end of the screw 8 and the support member 10
A spring 12 for urging the friction pad 6 together with the support member 10 in a direction of abutting the friction roller 4 is interposed between and.

Here, the friction pad separation method is as follows.
Compared with the friction roller separation method shown in FIG. 11, the number of parts is smaller and the structure is simple, so that the cost is low. However, since no positively giving frictional force "F _B" in the return direction between the friction pads 6 and the sheet 3, susceptible to variations in biasing force (pad pressure) "P", the heavy pad pressure "P" The prevention range is narrow. Normally, in this friction pad separation method, the spring 12 is used to obtain the pad pressure "P", and the pad pressure "P" is within the tolerance.
The friction pad 6 itself is attached to the sheet feeding cassette 5, and the positional deviation due to the attachment / detachment of the sheet feeding cassette 5 and the device body are attached. The pad pressure "P" may deviate from the double feed prevention range only by the designed displacement of the spring 12 due to a positional deviation due to the tolerance of the friction roller 4. When the pad pressure “P” is out of the double feed prevention range, the screw 8 is manually rotated to move the spring 12 and the friction pad 6 up and down, so that the value of the pad pressure “P” is double feed prevention range. Corrected to be within.

[0008]

As the equipment main body and the paper feed cassette 5 are used for a longer period of time, the pad pressure is reduced due to the positional displacement between the friction roller 4 and the friction pad 6, wear of the friction pad 6, and the like. "P" is out of the double feed prevention range, and double feed easily occurs. In such a case, it is possible to manually rotate the screw 8 to adjust the pad pressure "P" so that it falls within the double feed prevention range.
Since there is no means for detecting the pad pressure "P", it is impossible to detect how far the pad pressure is out of the double feed prevention range, and it is difficult to adjust the pad pressure after shipping.

[0009]

The invention according to claim 1 is
A manual moving member that is manually moved in a direction of coming into contact with and separating from a friction roller provided in the apparatus body, and comes into contact with an outer peripheral surface of the friction roller via a sheet to be fed and at least this friction. The friction pad is attached to the manual movement member so as to be movable in a direction of moving toward and away from the roller, and is provided between the friction pad and the manual movement member, and the friction pad contacts the friction roller. In a pad pressure adjusting device for a paper feeding cassette, wherein a biasing member for biasing in a contacting direction is provided in the paper feeding cassette, the pad when the friction pad contacts the outer peripheral surface of the friction roller via the paper. A sensor for detecting pressure is provided between the friction pad and the manual movement member.

According to a second aspect of the present invention, in the first aspect of the present invention, an electric sensor for electrically detecting the pad pressure is provided as a sensor, and an input / output terminal connected to the electric sensor is connected to a paper feed cassette. It was attached to the outer peripheral surface of.

According to a third aspect of the present invention, in the first aspect of the invention, an electric moving means that electrically operates is provided in place of the manual moving member, and an electric sensor for electrically detecting the pad pressure is used as a sensor. A sensor is provided, and input / output terminals connected to the electric sensor and the electric moving means are provided on the outer peripheral surface of the paper feed cassette, and the detection results from the electric sensor are connected to the input / output terminals. Based on the above, the control means for operating the electric moving means is provided in the device body.

[0012]

According to the first aspect of the present invention, since the pad pressure is detected by the sensor, it is possible to easily detect that the pad pressure is out of the double feed prevention range due to wear over time or the like. Based on the detection result of, the manual type moving member is operated to move the friction pad toward and away from the friction roller to adjust the pad pressure and set the pad pressure to an appropriate value within the double feed prevention range. It can be easily returned.

According to the second aspect of the invention, the pad pressure is detected by an electric sensor, and the pad pressure is simplified by connecting the display means for displaying the detected value to the input / output terminal provided on the outer peripheral surface of the paper feed cassette. When it is detected that the pad pressure is out of the double feed prevention range due to wear over time, the friction pad is brought into contact with and separated from the friction roller by operating the manual movement member. The pad pressure can be adjusted by moving in the direction, and the pad pressure can be easily returned to an appropriate value within the double feed prevention range. Further, the output from the electric sensor is detected by the detection unit provided in the main body of the device via the input / output terminal, and the friction roller is moved toward and away from the friction pad based on the detection result. If a friction roller moving mechanism is provided, the pad pressure can be automatically controlled at all times.

According to the third aspect of the present invention, the pad pressure is detected by the electric sensor, and the electric moving means operates based on the detection result from the electric sensor to bring the friction pad into and out of contact with the friction roller. To move to
The pad pressure can be automatically controlled at all times.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the invention described in claim 1 will be described with reference to FIG. The same parts as those described in FIG. 12 are designated by the same reference numerals, and the description thereof will be omitted. A device body (not shown) such as a copying machine is provided with one friction roller 4, and a paper feed cassette 5 for storing the paper 3 is detachably attached to the device body. Then, in the paper feeding cassette 5, as in the conventional example shown in FIG. 12, a screw 8 and a supporting member 10 which are manual moving members manually moved in a direction of coming into contact with and separating from the friction roller 4 are provided. The friction roller 4 is supported and slidably fitted in a hole 9 formed in the screw 8.
A friction pad 6 which is movable in the direction of contact with and away from the friction roller 4, and a direction in which the friction pad 6 is interposed between the upper end of the screw 8 and the support member 10 and the friction pad 6 contacts the outer peripheral surface of the friction roller 4. A spring 12 is provided which is a biasing member that biases to.

Next, a tension gauge 1 which is a sensor for detecting the pad pressure of the friction pad 6 which is in contact with the outer peripheral surface of the friction roller 4 via the paper 3 is provided.
3 is attached between the support member 10 and the screw 8.

In such a structure, the friction pad 6 is biased toward the friction roller 4 by the spring 12, and the spring is provided between the friction pad 6 and the friction roller 4 which are in contact with each other via the paper 3. The pad pressure based on the urging force of 12 acts, and this pad pressure is set to an appropriate value within the double feed prevention range. Further, the tension gauge 1 mounted between the support member 10 and the screw 8
3 indicates a value corresponding to the pad pressure.

Here, when the friction pad 6 is worn, the friction pad 6 and the support member 10 are pushed up by the urging force of the spring 12 and moved to the friction roller 4 side by an amount corresponding to the amount of wear. , At this time, spring 1
Since 2 is in the extended state, the pad pressure decreases. On the other hand, when the friction pad 6 and the support member 10 move to the friction roller 4 side, the value indicated by the tension gauge 13 changes because the distance between the support member 10 and the screw 8 widens, and the tension gauge 13 By looking at this indicated value, it can be known that the pad pressure has decreased, that is, the pad pressure is detected by the tension gauge 13. Then, when the pad pressure decreases and is out of the double feed prevention range, the spring 12 is compressed and the pad pressure is increased by manually rotating the screw 8 to move it to the friction roller 4 side. Can be returned to an appropriate value within the double feed prevention range.

In this way, the tension gauge 13 constantly detects the pad pressure.
It is possible to detect whether or not the pad pressure is out of the double feed prevention range by looking at the value indicated by, and if the pad pressure is out of the double feed prevention range, manually rotate the screw 8 to check the pad pressure. Easy to adjust.

Next, a second embodiment of the invention according to claim 1 will be described with reference to FIG. The same parts as those described in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. In this embodiment, two tension gauges 13, which are sensors, are attached between the support member 10 and the screw 8.

Therefore, when there are a plurality of moving directions of the friction pad 6, the average value of the pad pressures can be known by averaging the values indicated by these tension gauges 13, and the pad pressures can be prevented from double feeding. When it is out of the range, the pad pressure can be easily adjusted by manually turning the screw 8.

Next, a first embodiment of the invention described in claim 2 will be described with reference to FIGS. 3 and 4. The same parts as those described in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. A piezoresistive element 14, which is an electrical sensor for detecting pad pressure, is attached to the upper end of the screw 8, and a spring 12 is interposed between the upper end surface of the piezoresistive element 14 and the support member 10. It is equipped. The input / output terminal 1 connected to the piezoresistive element 14
5 is attached to a side surface portion of the outer peripheral surface of the paper feed cassette 5 that is not in contact with the device body.

In such a structure, a force corresponding to the pad pressure acts on the piezoresistive element 14 via the spring 12,
The piezoresistive element 14 detects the force and outputs according to the force. Then, by connecting a display means (not shown) for displaying the detection value detected by the piezoresistive element 14 to the input / output terminal 15, the pad pressure can be detected.

Here, when the friction pad 6 is worn, the friction pad 6 and the supporting member 10 are pushed up by the urging force of the spring 12 and moved to the friction roller 4 side by an amount corresponding to the amount of wear. , At this time, the spring 12
Becomes a stretched state, the pad pressure is reduced, and the force acting on the piezoresistive element 14 is also reduced accordingly. Therefore, the detection value output from the piezoresistive element 14 becomes small, and it is possible to detect that the pad pressure has decreased by displaying this detection value on the display means. Then, when the pad pressure decreases and is out of the double feed prevention range, the spring 12 is compressed and the pad pressure is increased by manually rotating the screw 8 to move it to the friction roller 4 side. Can be returned to an appropriate value within the double feed prevention range.

Next, a second embodiment of the invention according to claim 2 will be described with reference to FIGS. 5 and 6. The same parts as those described in FIGS. 1 to 4 are designated by the same reference numerals, and the description thereof will be omitted. In this embodiment, a spring 12 is interposed between the screw 8 and the supporting member 10, and a strain element 16 formed by rolling a thin plate into a substantially elliptical cross section is interposed between the screw 8 and the supporting member 10. In addition, a pair of strain gauges 17, which are electrical sensors, are attached to the flexure element 16. The input / output terminal 1 connected to the strain gauge 17
As shown in FIG. 4, 5 is attached to a side surface portion of the outer peripheral surface of the paper feed cassette 5 that is not in contact with the main body of the device.
A hole 18 for allowing the spring 12 to penetrate is formed in the central portion of the flexure element 16.

In such a structure, a force corresponding to the pad pressure acts on the strain-generating body 16, and the strain amount of the strain-generating body 16 due to this force is detected by the strain gauge 17 and output from the strain gauge 17. The pad pressure can be detected by connecting a display means for displaying the detected value to the input / output terminal 15.

Here, when the friction pad 6 is worn, the friction pad 6 and the support member 10 are pushed up by the urging force of the spring 12 and moved to the friction roller 4 side by an amount corresponding to the amount of wear. , At this time, the spring 12
Is in an extended state, the pad pressure is reduced, and the distance between the screw 8 and the support member 10 is widened, so that the strain amount of the flexure element 16 is reduced. Then, as the amount of strain of the flexure element 16 decreases, the detection value output from the strain gauge 17 also decreases. By displaying this detection value on the display means, it is detected that the pad pressure has decreased. be able to. Then, when the pad pressure decreases and goes out of the double feed prevention range, the screw 12 is manually rotated and moved to the friction roller 4 side, whereby the spring 12 is compressed and the pad pressure rises, and the pad pressure is reduced. It can be returned to an appropriate value within the double feed prevention range.

In the present embodiment, the strain-generating body 16 formed by rolling a thin plate into a substantially elliptical cross-section has been described as an example, but the shape of the strain-generating body 16 is not limited to this. is not.

Further, in the present embodiment and the embodiments described with reference to FIGS. 3 and 4, the strain gauge 17 and the piezoresistive element 14 were described as examples of the electrical sensor, but the electrical sensor is not limited to these. Any sensor that can electrically detect the pad pressure may be used.

Further, in the present embodiment and the embodiments described with reference to FIGS. 3 and 4, the case where the display means is connected to the input / output terminal 15 to detect the pad pressure when necessary has been described. A detection unit that is always connected to the input / output terminal 15 is provided in the device body, and a friction roller moving mechanism that moves the friction roller 4 based on the detection result from the detection unit is provided in the device body. The pad pressure may be automatically controlled at all times by operating the friction roller moving mechanism by closed loop control based on the detection result from the above.

Next, a first embodiment of the invention described in claim 3 will be described with reference to FIGS. 7 and 8 (hereinafter the same).
The same parts as those described with reference to FIGS. 1 to 6 are designated by the same reference numerals, and the description thereof will be omitted. The base 19 is fixed to the paper feed cassette 5, and the piezoresistive element 14 is mounted on the base 19 in the vertical direction (friction roller 4).
A piezoelectric element 20 which is an electric moving means that is polarized so as to expand and contract in a direction toward and away from the piezoresistive element 14 is stacked, and the spring 12 is provided between the upper end surface of the piezoresistive element 14 and the support member 10. Is installed. Further, an input / output terminal 21 connected to the piezoresistive element 14 and the piezoelectric element 20 is attached to the front surface portion of the outer peripheral surface of the sheet feeding cassette 5. The device body is connected to the input / output terminal 21 when the sheet cassette 5 is set, and controls the voltage applied to the piezoelectric element 20 based on the detection result from the piezoresistive element 14. Control means (not shown) is provided.

In such a structure, a force corresponding to the pad pressure acts on the piezoresistive element 14 via the spring 12,
The piezoresistive element 14 detects the force and outputs the detected value. Then, the detection value output from the piezoresistive element 14 is input to the control means via the input / output terminal 21 to detect the pad pressure. further,
A voltage corresponding to the detected pad pressure is applied from the control means to the piezoelectric element 20 via the input / output terminal 21, the piezoelectric element 20 expands and contracts according to the applied voltage, and the expansion and contraction of the piezoelectric element 20 causes the friction pad 6 to move. By moving the friction roller 4 toward and away from it, the pad pressure is automatically adjusted to a proper value within the double feed prevention range.

Here, when the friction pad 6 is worn, the friction pad 6 and the support member 10 are pushed up by the urging force of the spring 12 by an amount corresponding to the amount of wear as described in FIG. It moves to the friction roller 4 side, and at this time, the pad pressure decreases because the spring 12 is in the extended state, and the decrease in the pad pressure is detected by the piezoresistive element 14 and output from the piezoresistive element 14. The detected value is input to the control means. And
When the control means determines that the pad pressure has fallen below the double feed prevention range, the control means applies a voltage corresponding to the above-mentioned detected value to the piezoelectric element 20, and the piezoelectric element 20 is moved upward ( To the friction roller 4 side). When the piezoelectric element 20 extends upward, the spring 12
Is increased and the pad pressure is increased, and the pad pressure can be returned to an appropriate value within the double feed prevention range.

In this embodiment, the piezoelectric element 2
0, the piezoresistive element 14, and the spring 12 are stacked in this order from the bottom, but the stacking order of these is not limited to this, and can be arbitrarily changed.

Next, a second embodiment of the invention described in claim 3 will be described with reference to FIG. A base 22 is fixed to the paper feed cassette 5, and a piezoelectric element 23 that is polarized so as to be displaced in three directions indicated by arrows according to an applied voltage is attached to the base 22. The piezoelectric element 23 has a thin plate. Is fixed to a displacement magnifying member 24 having a substantially semicircular cross section, and the piezoelectric element 23 and the displacement magnifying member 24 move the friction pad 6 in the direction of contacting and separating from the friction roller 4. 25 are configured. A piezoresistive element 14 is attached to the top of the displacement magnifying member 24, and an air balloon 26, which is a biasing member, is interposed between the upper end surface of the piezoresistive element 14 and the support member 10. ..

The input / output terminal 21 connected to the piezoresistive element 14 and the piezoelectric element 23 is attached to the front portion of the outer peripheral surface of the sheet feeding cassette 5 as in the case shown in FIG. .. The device body is connected to the input / output terminal 21 when the sheet cassette 5 is set, and controls the voltage applied to the piezoelectric element 23 based on the detection result from the piezoresistive element 14. Control means (not shown) are provided.

In such a structure, a force corresponding to the pad pressure is applied via the air balloon 26 to the piezoresistive element 14.
The piezoresistive element 14 detects the force and outputs the detected value. Then, the piezoresistive element 14
The pad pressure is detected by inputting the detection value output from the control means through the input / output terminal 21. Further, a voltage corresponding to the detected pad pressure is applied from the control means to the piezoelectric element 23 via the input / output terminal 21,
The piezoelectric element 23 expands and contracts according to the applied voltage value, and the displacement amount is expanded by the displacement expanding member 24.
By moving the friction pad 6 toward and away from the friction roller 4, the pad pressure is automatically adjusted to an appropriate value within the double feed prevention range.

In the present embodiment, the electric moving means 25, the piezoresistive element 14, and the air balloon 26 are laminated in this order from the bottom, but the lamination order is not limited to this, and it is optional. Can be changed.

Next, a third embodiment of the invention described in claim 3 will be described with reference to FIG. A base 27 and a pair of fixed bases 28 are fixed to the paper feeding cassette 5, and a piezoelectric element 29 polarized so as to expand and contract in the arrow direction (left and right direction in the drawing) according to the applied voltage is fixed to the fixed base 28. The piezoelectric element 29 and the thin plate 30 are fixed via the thin plate 30, and an electric moving means 31 for moving the friction pad 6 in the direction of contacting and separating from the friction roller 4 is constituted. Here, the thin plates 30 have free ends at one ends extending in directions opposite to each other, and these free ends are fixed to the support member 10. A piezoresistive element 14 is attached to the base 27, and an air balloon 26, which is a biasing member, is interposed between the piezoresistive element 14 and the support member 10.

The input / output terminal 21 connected to the piezoresistive element 14 and the piezoelectric element 29 is attached to the front surface of the outer peripheral surface of the sheet feeding cassette 5 as shown in FIG. .. The device body is connected to the input / output terminal 21 when the sheet cassette 5 is set, and controls the voltage applied to the piezoelectric element 29 based on the detection result from the piezoresistive element 14. Control means (not shown) are provided.

In this structure, the force corresponding to the pad pressure is applied to the piezoresistive element 14 via the air balloon 26.
The piezoresistive element 14 detects the force and outputs the detected value. Then, the piezoresistive element 14
The pad pressure is detected by inputting the detection value output from the control means through the input / output terminal 21. Further, a voltage according to the detected pad pressure is applied from the control means to the piezoelectric element 29 via the input / output terminal 21,
The piezoelectric element 29 expands and contracts in the arrow direction (horizontal direction) according to the applied voltage, and the thin plate 30 is displaced in the arrow direction (vertical direction) due to the expansion and contraction of the cantilever.
By the vertical displacement of the thin plate 30, the friction pad 6 moves together with the support member 10 in the direction of coming into contact with and separating from the friction roller 4, and the pad pressure is automatically adjusted to an appropriate value within the double feed prevention range. Be done.

[0042]

According to the first aspect of the present invention, the friction member is moved through a manual type moving member which is manually moved in a direction in which it comes in contact with and separates from a friction roller provided in the apparatus body. Between the friction pad that is abutted on the outer peripheral surface of the roller and is attached to the manual movement member so as to be movable at least in the direction in which the friction roller is brought into and out of contact with the friction roller, and between the friction pad and the manual movement member. A pad pressure adjusting device for a paper feed cassette, wherein the friction pad is provided on the paper feed cassette, and a biasing member that biases the friction pad in the direction of contacting the friction roller is provided in the paper feed cassette. By providing a sensor that detects the pad pressure when it comes into contact with the outer peripheral surface of the friction roller between the friction pad and the manual movement member. It is possible to easily detect that the pad pressure deviates from the double feed prevention range by the detection by the sensor, and further operate the manual movement member based on the detection result from the sensor to move the friction pad against the friction roller. There is an effect that the pad pressure can be easily adjusted such that the pad pressure is returned to an appropriate value within the double feed prevention range by moving the pad pressure in the contact and separation directions.

According to a second aspect of the present invention, in the first aspect of the invention, an electric sensor for electrically detecting the pad pressure is provided as a sensor, and an input / output terminal connected to the electric sensor is connected to a paper feed cassette. Since it is attached to the outer peripheral surface of the pad, the pad pressure detected by the electric sensor can be displayed on the display means by connecting the display means to the input / output terminal, and thus the pad pressure can be easily detected. Further, the pad pressure is returned to an appropriate value within the double-feeding prevention range by operating the manual movement member based on the detection result from the sensor to move the friction pad in the direction of moving toward and away from the friction roller. The pad pressure can be easily adjusted, and the detection value from the electrical sensor can be detected by the detection unit provided in the device body via the input / output terminal. By providing the friction roller moving mechanism for moving the direction toward or away from the friction roller based on a detection result to the friction pad has the effect of such a control pad pressure it can be automatically carried out at all times.

According to a third aspect of the present invention, in the first aspect of the invention, an electric moving means that electrically operates is provided in place of the manual moving member, and an electric sensor for electrically detecting pad pressure is used as a sensor. A sensor is provided, and an input / output terminal connected to the electric sensor and the electric moving means is provided on the outer peripheral surface of the sheet feeding cassette, connected to these input / output terminals, and detected from the electric sensor. By providing the control means for operating the electric moving means on the basis of the result in the main body of the apparatus, the pad pressure for maintaining the pad pressure at an appropriate value within the double-feeding prevention range can be automatically and constantly adjusted. Therefore, it is possible to reliably prevent the occurrence of double feeding, and in addition, in the control for operating the electric moving means by the control means, mainly by adding the control software. It has an effect or the like can be reduced in cost.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of the invention according to claim 1.

2 is a perspective view showing a second embodiment of the invention according to claim 1. FIG.

FIG. 3 is a front view showing a first embodiment of the invention according to claim 2;

FIG. 4 is a perspective view showing the entire paper feed cassette.

FIG. 5 is a front view showing a second embodiment of the invention according to claim 2;

FIG. 6 is a perspective view showing a state in which a strain gauge is attached to a flexure element.

FIG. 7 is a front view showing a first embodiment of the invention according to claim 3;

FIG. 8 is a perspective view showing the entire paper feed cassette.

FIG. 9 is a front view showing a second embodiment of the invention according to claim 3;

FIG. 10 is a front view showing a third embodiment of the invention according to claim 3;

FIG. 11 is a front view showing a conventional example.

FIG. 12 is a front view showing another conventional example.

[Explanation of symbols]

 3 Paper 4 Friction Roller 5 Paper Feed Cassette 6 Friction Pad 8 Manual Type Moving Member 12, 26 Energizer 13 Sensor 14 Electrical Sensor 15, 21 Input / Output Terminal 17 Electrical Sensor 20, 25, 31 Electrical Moving Means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroyuki Horiguchi 1-3-6 Nakamagome, Ota-ku, Tokyo In Ricoh Co., Ltd. (72) Junichi Takahashi 1-3-6 Nakamagome, Ota-ku, Tokyo Shares Within Ricoh Company (72) Inventor Motomi Ozaki 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Company, Ltd.

Claims (3)

[Claims] 1. A manual moving member that is manually moved in a direction of coming into contact with and away from a friction roller provided in a main body of the apparatus, and is brought into contact with an outer peripheral surface of the friction roller via a sheet to be fed. And a friction pad attached to the manual movement member so as to be movable at least in a direction of moving toward and away from the friction roller, and the friction pad is provided between the friction pad and the manual movement member. In a pad pressure adjusting device for a paper feeding cassette, wherein a biasing member for biasing the friction roller is provided in the paper feeding cassette, the friction pad contacts the outer peripheral surface of the friction roller via the paper. A sensor for detecting a pad pressure at the time of contact is provided between the friction pad and the manual movement member, and the pad of the paper feed cassette is characterized. Pressure adjustment device. 2. An electric sensor for electrically detecting a pad pressure is provided as a sensor, and an input / output terminal connected to the electric sensor is attached to an outer peripheral surface of a sheet feeding cassette. Pad pressure adjusting device for the paper feed cassette described. 3. An electric moving unit that operates electrically instead of the manual moving member is provided, and an electric sensor that electrically detects a pad pressure is provided as a sensor, and the electric sensor and the electric moving unit are provided. I / O terminals connected to and are provided on the outer peripheral surface of the paper feed cassette, and are connected to these I / O terminals and control means for operating the electric moving means based on the detection result from the electric sensor. The pad pressure adjusting device for a paper feed cassette according to claim 1, wherein the pad pressure adjusting device is provided in the main body of the device.