JP2000177869A - Sheet feeder, image reader, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the double feed rate by surely separating the tips of a plurality of documents stacked with each other in such a state as slipping them one by one by a separation pad. SOLUTION: In a sheet feeder having a feed drive member 6 driven for feeding sheet materials 6 and a separation member 3 abutting on the ends of a plurality of sheet materials 1 stacked on the feed drive member and separating the sheet materials, the ends of the sheet materials are surely separated in such a state as being slipped one by one so as to reduce the double feed rate of the sheet materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device for conveying or feeding a sheet material (such as a document) and a sheet feeding device.

[0002]

2. Description of the Related Art FIG. 6 shows a configuration of a conventional sheet feeding device (sheet feeding device) used in an image reading apparatus capable of continuously reading a plurality of sheets of a facsimile or copy original (sheet material). Is shown. In the image reading apparatus as described above, the document reading unit 108 is provided so as to be located below the document 101 to be fed in order to stack the documents 101 after being read in the same order as before feeding. Can be Then, the document 101 is set with the surface of the document facing down, and the sheet feeding roller 106 provided below the document 101 is driven to feed the document.

The setting of the original 101 on the paper feed tray 111 is detected by a sensor 102, and this detection signal is transmitted to the main body of the apparatus. Also, the paper feed roller 10
6, the leading end of the original 101 placed diagonally on the paper feed roller 106 is
The sheets are loosened so that they can be easily fed one by one.

The separation pad 103 is pressed downward by a spring 104, and the upper end of the spring 104 is fixed at a fixed end 10.
5 fixed. The set document is sent to a set of transport rollers 107 by a feed roller 106. The document leading edge detection sensor 113 informs the apparatus body that the leading edge of the document has reached the position of the transport roller 107. One set of transport rollers 107 transports the document 101 to the document reading unit 108. A paper discharge roller 112 conveys the document 101 to a paper discharge tray 109, and a document reading unit 108.
The original 101 is brought into close contact with the original, and the reading accuracy is improved as compared with the case where the original is not in close contact with the original reading unit 108.

[0005]

In the above-mentioned conventional paper feeder, ideally, the state of the leading edge of the original abutting on the separation pad 105 is determined by the weight of the original 101 and the direction in which the original 101 is inserted. Since the separation pad 105 is provided obliquely, the leading edge of the document is gradually shifted one by one as shown in FIG.

However, due to the frictional force between the originals, the leading ends of the originals are actually arranged irregularly as shown in FIG. 7, which is one of the causes of the double feed of the originals.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet feeding apparatus capable of reducing a double feed rate by reliably loosening the leading ends of a plurality of originals one by one by a separation pad.

[0008]

In order to achieve the above object, according to the present invention, a supply driving member such as a paper feed roller driven for supplying a sheet material and a plurality of sheets are superimposed on the supply driving member. And a separating member that abuts on an end of the sheet material placed thereon and separates the sheet material, the piezoelectric vibrating body (or the piezoelectric vibrator), the motor, and the like having the separating member attached thereto. By vibrating by the vibrating means, or by forming the separating member itself by a piezoelectric vibrating body, the ends of the plurality of sheet materials abutting the separating member are loosened so as to be surely shifted one by one,
It tries to reduce the double feed rate of the sheet material.

In the above invention, the generation of noise is suppressed by vibrating the vibrating means or the separating member at a frequency outside the audible range, or by setting the driving frequency of the piezoelectric vibrating body at a frequency outside the audible range of humans. It is desirable to do.

[0010] Further, the vibration of the separation member is reduced when it is detected that the sheet material is placed on the supply drive member or when a supply start signal output in response to a user operation or the like is output. It is desirable to start the operation and then vibrate the sheet material for a predetermined period of time sufficient to regularly loosen the edges, so as to reduce the power consumption and eliminate the adverse effect on the outside due to unnecessary vibration.

Further, when the sheet material is supplied to the image reading section or the image forming section, the separating member is set to a predetermined time set according to the time required until the image reading section or the image forming section can operate stably. It is desirable to prevent the image reading speed and the image forming speed from becoming slower than in the related art by causing the sheet material to start being supplied almost simultaneously with the end of the vibration.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 shows a sheet feeding device (sheet conveying device) according to a first embodiment of the present invention. This paper feeding device is used for an image reading device such as a facsimile or a copy that can continuously read a plurality of originals (sheet materials). In such an image reading apparatus, it is desirable that the overlapping state (order and direction) after the original 1 is fed and read is the same as before the original is fed. For this reason, in the present embodiment,
The document reading unit (image reading unit) 8 is arranged at a position below the document 1 to be fed, and the document 1 is set with its front surface facing downward. (By roller 6).

In the vicinity of the front end of the paper feed tray 11 in the paper feed direction, a paper feed roller (supply drive member) 6 is arranged so that its upper part is exposed above the paper feed tray 11. As described above, when a plurality of stacked originals 1 with their surfaces facing downward are set on the paper feed tray 11, the leading end portions of these originals 1 are placed on the paper feed roller 6. The document set is transmitted to a control circuit (not shown) provided in the apparatus main body by a detection signal from a sensor 2 which is pushed on by the document 1 and turned on.

Above the paper feed roller 6, a separation pad 3 is provided.
Are arranged so as to form an acute angle with the document placement surface of the paper feed tray 11. The upper end of the separation pad 3 is pressed downward (that is, in the direction of the paper feed roller 6) by a spring 4 attached to a fixed end 4 of the apparatus main body or the like.

The lower end of the separation pad 3 is in contact with the leading end of the original 1 placed on the paper feed roller 6. On an upper surface of the separation pad 3, a piezoelectric vibrator (for example, a piezoelectric element attached to an upper surface or a side surface of an elastic member, also referred to as a piezoelectric vibrator) 10 is attached.

Here, if the originals 1 are set on the paper feed tray 11 and their leading ends are simply brought into contact with the separation pad 3, as shown in FIG. May be irregularly displaced (unraveled) due to friction.

However, by applying a drive signal of a predetermined frequency to the piezoelectric vibrating body 10 and causing the separation pad 3 to vibrate together with the piezoelectric vibrating body 10, the leading end portion of the original 1 can be surely adjusted to the rule shown in FIG. In other words, each document is loosened so that it gradually shifts backward in the paper feeding direction.

The piezoelectric vibrator 10 and the separation pad 3
Preferably includes the direction of the diameter of the paper feed roller 6 (elongation of the spring 4).

The frequency of the drive signal applied to the piezoelectric vibrating body 10 is preferably a frequency outside the human audible range (10 Hz to tens kHz). Alternatively, it is preferable that the vibration frequency of the separation pad 3 be outside the audible range of humans.
Thereby, generation of noise due to vibration of the separation pad 3 can be suppressed.

The originals 1 set on the paper feed tray 11 and having their leading ends loosened regularly are supplied one by one to the image reading section 8 by a paper feed roller 6 driven to rotate by a motor or the like. . In this way, it is possible to reduce the rate at which a plurality of originals 1 are supplied while being stacked, that is, the double feed rate.

A set of transport rollers 7 for transporting the document 1 therebetween is disposed between the paper feed roller 6 and the image reading section 8.

At the position of the transport roller 7, a document leading edge detection sensor 13 is disposed. When the leading edge of the document 1 reaches the position of the document leading edge detection sensor 13, a detection signal is output from the sensor 13 to the control circuit, and the control circuit starts the operation of the document reading unit 8. Document reading unit 8 is LED
And a reading element such as a CCD line sensor. The document 1 that has reached the position of the document reading section 8 is brought into close contact with the document reading section 8 by a discharge roller 12 that is disposed above the document reading section 8 and is driven to rotate by a motor or the like, and is placed on the discharge tray 9. It is conveyed toward. In addition, by bringing the document 1 into close contact with the document reading unit 8, the reading accuracy of the document 1 can be improved as compared with a case where the document 1 is not closely attached.

FIG. 4 shows a control sequence of the image reading apparatus by the control circuit. When the document 1 is set on the paper feed tray 11 and the setting of the document 1 is detected by the sensor 2 (step S1), a drive signal is applied to the piezoelectric vibrator 10 to vibrate the separation pad 3 (step S2). .

A predetermined time from the start of the application of the driving signal to the piezoelectric vibrating body 10, for example, sufficient for the leading end of the document 1 set on the paper feed tray 11 to be regularly loosened by the vibrating separation pad 3. When the time required for the original reading light source such as the LED lamp in the original reading section 8 to stabilize (ie, the time during which the original reading section 8 can operate stably) elapses, the application of the drive signal is stopped. (Step S4). By setting the driving time of the piezoelectric vibrating body 10 as described above, it is possible to reduce the power consumption by omitting the excessive driving time and to reduce the power consumption.
In addition, it is possible to eliminate a bad influence on the outside due to the vibration of the separation pad 3.

Thereafter, in response to a paper feed start signal (supply start signal) output in response to a user's switch operation, or in response to a supply start signal generated in the control circuit upon completion of driving of the piezoelectric vibrating body 10. The paper feed roller 6 and the image reading unit 8
And a paper receiving mode for driving the paper discharge roller 12 (step S5).

In particular, the paper feed receiving mode is set in response to a supply start signal generated in the control circuit when the driving of the piezoelectric vibrator 10 is completed, and the paper feed roller 6 and the like are driven almost simultaneously (simultaneously or immediately thereafter). By doing so, in combination with the setting of the driving time of the piezoelectric vibrating body 10, it is possible to prevent the reading speed from becoming slower than that of a conventional apparatus that does not vibrate the separation pad.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention.
4 illustrates a control sequence of the image reading apparatus according to the embodiment. The configuration of the image reading apparatus according to the present embodiment is the same as that of the first embodiment.
Since this embodiment is the same as that described in FIG. 1 of the embodiment, in this embodiment, each component will be described with the same reference numeral as in the first embodiment. .

The original 1 is set on the paper feed tray 11,
When the control circuit detects the arrival of the paper feed start signal output in response to the user's switch operation or detects the paper feed start signal automatically generated in the control circuit (step S11), the piezoelectric vibration occurs. A drive signal is applied to the body 10 to vibrate the separation pad 3 (Step S12).

A predetermined time from the start of application of the driving signal to the piezoelectric vibrating body 10 is required for a predetermined time, for example, for the leading edge of the document 1 set on the paper feed tray 11 to be regularly loosened by the vibrating separation pad 3. Time until the light source for reading a document such as an LED lamp in the document reading section 8 becomes stable (that is, the time when the document reading section 8 can operate stably, and is sufficient for the document 1 to be loosened regularly. After that, the application of the drive signal is stopped (step S14). By setting such a driving time of the piezoelectric vibrating body 10, it is possible to reduce the power consumption by omitting the excessive driving time and to prevent the piezoelectric vibrating body 10 and the separation pad 3 from adversely affecting the outside. Can be eliminated.

At almost the same time as the vibration of the piezoelectric vibrating body 10 ends (simultaneously, immediately before or immediately after), the sheet feeding roller 6
Is driven to start feeding the original 1, and at the same time, the image reading section 8 and the discharge roller 12 are driven to start image reading (step S15). Thus, in combination with the setting of the driving time of the piezoelectric vibrating body 10 described above, it is possible to prevent the reading speed from being reduced as compared with the conventional apparatus.

In each of the above embodiments, the case where the separation pad 3 is vibrated by attaching the piezoelectric vibrator 10 to the separation pad 3 has been described. However, in the present invention, the separation pad itself is formed by the piezoelectric vibrator. It may be.
In this case, it is desirable that the lower surface of the piezoelectric vibrator (the surface in contact with the document) is in a form in which friction required to loosen the document occurs.

In each of the above embodiments, the separation pad 3
Although the case where the vibration is caused by the piezoelectric vibrator 10 has been described, the separation pad may be vibrated by a motor or other suitable material for generating vibration.

Further, in each of the embodiments described above, the sheet supply device used in the image reading apparatus has been described. It can also be used to supply.

In each of the above embodiments, the case where the original 1 is driven to be fed by the feed roller 6 has been described.
The present invention relates to a supply driving member (for example, a belt) other than a roller.
The present invention can also be applied to a case in which the sheet is driven for feeding.

[0035]

As described above, according to the present invention,
By vibrating the separating member, it is possible to loosen the end portions of the plurality of sheet materials abutting on the separating member so as to be surely shifted one by one (regularly), thereby reducing the double feeding rate of the sheet material. Can be done.

In the above invention, the generation of noise can be suppressed by vibrating the vibrating means or the separating member at a frequency outside the audible range, or setting the driving frequency of the piezoelectric vibrator to a frequency outside the audible range of humans. .

Further, when it is detected that the sheet material is placed on the supply driving member, the vibration of the separating member is started, and the driving member is driven for a time sufficient to regularly loosen the end of the sheet material. By doing so, it is possible to reduce the power consumption and eliminate the adverse effect on the outside due to unnecessary vibration.

In particular, when the sheet material is supplied to the image reading section or the image forming section, the separating member is vibrated for a time set according to the time required until the image reading section or the image forming section can operate stably. By starting the supply of the sheet material almost simultaneously with this, it is possible to prevent the image reading speed and the image forming speed from being reduced as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a document reading apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state of a leading end of a document before vibration of a piezoelectric vibrator in the document reading apparatus.

FIG. 3 is an explanatory diagram showing a state of a leading end of a document after vibration of a piezoelectric vibrator in the document reading apparatus.

FIG. 4 is a control flowchart of the document reading apparatus.

FIG. 5 is a control flowchart of a document reading apparatus according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram of a conventional document reading apparatus.

FIG. 7 is an explanatory view showing a state of an actual leading edge of a document in a conventional document reading apparatus.

FIG. 8 is an explanatory diagram showing an ideal state of the leading edge of a document.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Document 2 ... Document presence detection sensor 3 ... Separation pad 4 ... Spring 5 ... Fixed end 6 ... Feed roller 7 ... One set of transport rollers 8 ... Document reading unit 9: Discharge tray 10: Piezoelectric vibrator 11: Paper feed tray 12: Discharge roller 13: Document leading edge detection sensor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H076 BA17 BA24 BA64 BB02 BB05 3F343 FA03 FB03 FC01 GA02 GB02 GC01 GD01 HA12 HA33 HB01 JA01 JD03 JD08 JD26 JD33 LA04 LA18 LB08 LC02 LC19 LD04 LD13 MA03 MA13 MA14 MB23 MA33 MB45 MB03 MB MC08 MC18 MC22 MC23 5C062 AB17 AB22 AB30 AB31 AB35 AC13 AC65 AD01 AD06 BA00

Claims (20)

[Claims] 1. A supply driving member driven to supply a sheet material, and a separation unit configured to abut an end of a plurality of sheet materials stacked on the supply driving member to separate the sheet materials. A sheet feeding device comprising: a sheet feeding device, comprising: a vibration unit configured to vibrate the separation member. 2. The sheet feeding apparatus according to claim 1, wherein said vibration means is a piezoelectric vibrator attached to said separation member. 3. A supply driving member driven for supplying a sheet material, and a separation device for abutting an end portion of a plurality of sheet materials placed on the supply driving member and separating the sheet materials. A sheet feeding device having a member, wherein the separation member is formed of a piezoelectric vibrator. 4. The sheet conveying device according to claim 3, wherein a contact surface of the piezoelectric vibrator with the sheet material is formed as a friction surface necessary for separating the sheet material. 5. The sheet separating apparatus according to claim 1, wherein the separating member abuts obliquely on a front end of each of the plurality of sheet materials so as to gradually shift the plurality of sheet materials rearward in a supply direction. A sheet feeding device according to claim 1. 6. The sheet feeding apparatus according to claim 1, wherein the separation member vibrates at a frequency outside an audible range. 7. The sheet feeding device according to claim 2, wherein the driving frequency of the piezoelectric vibrator is a frequency outside the audible range. 8. A detecting means for detecting whether or not a sheet material is placed on the supply driving member, and when the detecting means detects that the sheet material is mounted on the supply driving member. 8. The sheet feeding apparatus according to claim 1, further comprising a control unit for starting vibration of the separation member. 9. The control device according to claim 1, further comprising a control unit for starting the vibration of the separation member when a supply start signal instructing the start of the supply of the sheet material is output. Sheet feeding device. 10. The apparatus according to claim 8, wherein the control means vibrates the separation member for a predetermined time, and permits the supply drive member to be driven almost simultaneously with the end of the vibration of the separation member. A sheet feeding device as described in the above. 11. A sheet supply device according to claim 1, further comprising: an image reading unit that reads an image formed on a sheet material supplied from the sheet supply device. Image reading device. 12. The sheet supply device according to claim 10, further comprising: an image reading unit that reads an image formed on a sheet material supplied from the sheet supply device. An image reading apparatus, wherein the image reading apparatus is set in accordance with a time required for a reading unit to be able to operate stably. 13. The image reading section has a light source for reading an image, and the predetermined time is set according to a time required until light emission of the light source is stabilized. The image forming apparatus according to claim 12. 14. An image forming apparatus, comprising: the sheet feeding device according to claim 1; and an image forming unit that forms an image on a sheet material supplied from the sheet feeding device. apparatus. 15. The sheet supply device according to claim 10, further comprising: an image forming unit configured to form an image on a sheet material supplied from the sheet supply device; An image forming apparatus, which is set according to a time required until a stable operation can be performed. 16. A sheet feeding roller for starting a sheet feeding operation at a sheet feeding timing, a separation pad for separating a plurality of sheets stacked on the sheet feeding roller, and a sheet material is stacked. A sheet feeder having a sheet feed tray, wherein the separation pad is vibrated by a piezoelectric vibrator. 17. A sheet feeding apparatus, comprising: a sheet feeding roller for starting a sheet feeding operation at a sheet feeding timing; and a separation pad for separating a plurality of sheets stacked on the sheet feeding roller. A sheet feeding device, wherein the separating member is formed by a piezoelectric vibrator in which a contact surface with the sheet material is formed as a friction surface necessary for separating the sheet material. 18. A sensor for detecting the presence or absence of a document, a piezoelectric vibrator that vibrates when the document is placed on a paper feed tray, and a paper feeder that feeds the document from below when the vibration is completed. A paper roller, a separation pad installed at an oblique angle to the insertion direction of the document, a spring for pressing the separation pad against the document, a fixed end member for fixing one end of the spring, and the document to the discharge roller. A transport roller for transporting, a document leading edge detection sensor for detecting the leading edge of the document, an image reading unit for reading an image formed on the document, and a paper discharge for bringing the document into close contact with the image reading unit and discharging the document. In an image reading apparatus having a roller and a discharge tray for stacking discharged documents, the piezoelectric vibrator is adhered to an upper portion of the separation pad, and the pressure is set at the same time when the document is set on the paper feed tray. Image reading apparatus vibrator to vibrate a predetermined time, and permits the reception of the time the paper feed start signal and the vibration is terminated. 19. A sensor for detecting the presence / absence of a document, a piezoelectric vibrator vibrating when the document is placed on the paper feed tray, and a feeder for feeding the document from below when the vibration is completed. A paper roller, a separation pad installed at an oblique angle to the insertion direction of the document, a spring for pressing the separation pad against the document, a fixed end member for fixing one end of the spring, and the document to the discharge roller. A transport roller for transporting, a document leading edge detection sensor for detecting the leading edge of the document, an image reading unit for reading an image formed on the document, and a paper discharge for bringing the document into close contact with the image reading unit and discharging the document. In an image reading apparatus having a roller and a discharge tray for stacking discharged documents, the piezoelectric vibrator is bonded to an upper portion of the separation pad, and when a sheet feeding start signal is received, the piezoelectric vibrator is But Image reading apparatus characterized by vibrating constant time, begins at the same time the paper feeding and the vibration is terminated. 20. The driving frequency of the piezoelectric vibrator is a frequency outside the audible range.
The image reading device according to claim 1.