JP2003040474A - Sheet supplying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet supplying device enabling to effectively use by accurately estimating a life of a separation roller provided on a paper feeding roller. SOLUTION: A separation roller shaft 125 of a paper feeding device 30 continues to rotate in an opposite direction to a carrying direction of a sheet S or does not rotate any more when a time of the life of the separation roller shaft 125 is over. A control circuit determines the life of the separation roller 124 by recognizing continuous rotation in the opposite direction to the carrying direction of the sheet S or stop of rotation of the separation roller shaft 125. For example, the control circuit recognizes that the separation roller 124 stops rotating when a signal output is not detected for at least two seconds after detection of the signal output at optional timing during operation of the paper feeding device 30, and determines the life of the separation roller 124.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device that is provided in an image forming apparatus such as a copying machine or a facsimile that forms an image on a sheet and that appropriately feeds the sheet.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus, such as an electrophotographic copying machine or a printer, which processes predetermined image information, re-forms it on a sheet, and discharges it, is well known.

In this type of image forming apparatus, sheets (for example, recording paper) on which an image is formed are stacked and stored in a sheet feeding device (paper feeding device) inside the main body of the image forming apparatus, and are appropriately stored. It is supplied to the image forming unit at a timing.

FIG. 8 schematically shows a main part of a sheet feeding device used in such an image forming apparatus.

In FIG. 8, a member 501 is a pickup roller, a member 502 is a conveying roller, a member 503 is a conveying roller shaft, a member 504 is a separating roller, a member 505 is a separating roller shaft, a member 506 is a pressure spring, and a member 507 is a member. The solenoid, the member 508 is a drawing roller, and the member 509 is a timing belt. Here, when the sheet S is pushed up to a height where it comes into contact with the pickup roller 501, the sheet S is sent to the separation unit by the rotation of the pickup roller 501.
In the separation unit, a separation roller 504, which is given a rotational force in the direction shown in the figure via a conveyance roller 502 and a torque limiter, is arranged so as to face the paper surface. As a result, when a plurality of sheets S are fed, only the uppermost sheet is conveyed, and the other sheets are pushed back by the separation roller. Then, the sheet S conveyed by the conveying rollers is fed to the image forming unit (not shown) by the pull-out rollers 508.

When the number of fed sheets is accumulated, the separation roller has a friction on the surface of the roller and the sheet separation ability is deteriorated. Therefore, it is necessary to replace the separation roller with another separation roller. . A preset number of sheets to be fed and the degree of slippage of the roller surface are used as the criteria for replacing the separation roller. That is, it is possible to predict the number of fed sheets that will reach the life of the roller by experiments, replace the rollers based on the estimated number of fed sheets, or check the slippage of the rollers as appropriate, and replace the rollers according to the sliding condition. It is common.

[0007]

However, since the life of the roller varies depending on the type of paper used, it is difficult to grasp the accurate life and replace the roller. At present, the separation roller is effectively used. I can't say that

The present invention has been made in view of the above circumstances, and its purpose is to accurately predict the life of the separation roller provided in the paper feed roller, and to effectively use the separation roller. Another object of the present invention is to provide a sheet feeding device that can be used effectively.

[0009]

In order to achieve the above object, the present invention provides a sheet feed tray for stacking sheet bundles, and a top sheet of the sheet bundles stacked on the sheet feed tray. A feeding means that abuts and directs a plurality of sheets forming the sheet bundle in a predetermined direction in order from the top, and a conveyance that abuts the fed sheets and conveys the sheets along a predetermined conveyance path surface. Means, and a separation roller that abuts the surfaces of the sheets that are sent out from the paper feed tray in an overlapping manner toward the conveying means, and is rotationally driven so as to push back the overlapped sheets to the paper feed tray.
In a sheet feeding device having a light-emitting element, a light-receiving element that receives light emitted from the light-emitting element and outputs a signal according to the amount of light, and the light-receiving sensor according to the rotation phase of the separation roller. A light receiving amount changing means for changing the light receiving amount of, a rotation direction detecting means for detecting a rotating direction of the separation roller based on the light receiving amount of the light receiving sensor to be changed, and based on the detected rotation direction, And a life determining unit that determines a life of the separation roller.

Further, the light receiving amount changing means includes a disk provided with at least one hole and rotating together with the separating roller, and the light receiving sensor is provided with the light emitted from the light emitting element on the disk. Light is received through a hole, and the rotation direction detection means may detect the rotation direction of the separation roller based on the timing at which the light receiving sensor receives the light emitted by the light emitting element.

Further, it is preferable that a plurality of the holes are provided in the disk at unequal intervals.

Further, it is preferable that the light receiving sensor is arranged substantially coaxially with the separating roller.

Further, the light receiving amount changing means has a plurality of mirrors each having a different reflection angle and rotating in synchronization with the separation roller, and each of the mirrors has a specific rotation phase. In this case, the light emitted from the light emitting element may be reflected and received by the light receiving sensor.

The plurality of mirrors may be integrated with the separating roller.

The life determining means determines the life of the separating roller when the separating roller is continuously rotated in the reverse direction with respect to the conveying direction a specified number of times or more, or when the stationary state is a specified time or more. Good to do.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) An embodiment in which the sheet feeding apparatus of the present invention is applied to a sheet feeding apparatus of an image forming apparatus will be described below with reference to the drawings.

FIG. 1 is a side sectional view schematically showing the internal structure of an image forming apparatus (copying machine) incorporating the sheet feeding device of this embodiment.

The copying machine 1 shown in FIG. 1 reads image information on a document and prints it on a sheet stored in its sheet feeding device.
It has a function of copying this image information.

As its basic structure, first, as shown in FIG. 1, an original table 2 made of a transparent glass plate is fixedly provided on the upper part of a copying machine (copying machine main body) 1. The member 3 is a manuscript pressure signboard, and presses and fixes the manuscript O placed at a predetermined position on the manuscript table 2 with the image surface facing downward. Below the document table 2, a lamp 4 for illuminating the document O,
Reflecting mirrors 5, 6, 7, 8, 9, 10 and an imaging lens 11 for guiding the illuminated optical image of the original O to the photosensitive drum 12.
An optical system consisting of and is provided. The lamp 4 and the reflecting mirrors 4, 5, 6, and 7 move in the direction of arrow a at a predetermined speed to scan the document O.

The image forming section includes a photosensitive drum 12 and a charger 13 for uniformly charging the surface of the photosensitive drum 12.
And a development for forming a toner image to be transferred onto the sheet S by developing the electrostatic latent image formed by the optical image emitted from the optical system on the surface of the photosensitive drum 12 charged by the charger 13. And a transfer charger 1 for transferring the toner image developed on the surface of the photosensitive drum 12 to the sheet S.
9, a separation charger 20 for separating the sheet S having the toner image transferred from the photosensitive drum 12, and a cleaner 26 for removing the toner remaining on the photosensitive drum 12 after the toner image is transferred. ing.

On the downstream side of the image forming section, a conveying section 21 for conveying the sheet S on which the toner image is transferred, and an image on the sheet S conveyed by the conveying section 21 are fixed as a permanent image. A fixing device 22 is provided. Further, a discharge roller 24 for discharging the sheet S having the image fixed by the fixing device 22 from the copying machine main body 1 is provided, and the sheet discharged by the discharging roller 24 is provided outside the copying machine main body 1. A discharge tray 25 for receiving S is provided.

A well-known control circuit including a CPU, a RAM, a ROM and the like operates the drive system of the image forming unit based on input information from an operation panel (not shown) provided outside the copying machine 1 and the like. Control the operation of the drive system of the sheet feeding devices 30 to 33.

Paper feeders 30, 31, 32, and 33 are provided below the image forming section of the copying machine main body 1. Each sheet feeding device has a function of stacking and stocking recording sheets (sheets) of different sizes and types and appropriately supplying the recording sheets (sheets) to the image forming unit.

Next, the structures and functions of the sheet feeding devices (sheet feeding devices) 30 to 33 incorporated in the copying machine body 1 will be described in detail. The sheet feeding devices 30 to 33 differ in the size and type of sheets to be stored, and have the same basic structure and operation mode. Here, in particular, the sheet feeding device 3 is used.
The structure and the like of only 0 will be described.

FIG. 2 shows a sheet feeding device 3 according to this embodiment.
It is a perspective view which shows the main structures of 0.

The sheet feeding device 30 shown in FIG. 2 has a function of stacking and storing sheets and supplying the sheets to the image forming section at appropriate timing.

As shown in the drawings, the sheet feeding device 30 includes a sheet feeding tray 120 (see FIG. 1) for stacking and storing sheets, and
A pickup roller 121, a paper feed roller 122, a separation roller 124, a separation roller life detection mechanism 30A, etc. are provided as main parts.

In the paper feeding device 30, the axial torque generated by the driving means such as a stepping motor is transmitted to the pickup roller 121, the paper feeding roller 122, and the separation roller 124, and each roller starts to rotate. The sheets S stacked in the paper feed tray are conveyed by the pickup roller 121 to the downstream side of the paper feed. Pickup roller 1
21, a paper feed roller 122 and a paper feed roller 12
2 and a separation roller 124 that comes into pressure contact with each other.
The roller pair including the rollers 122 and 124 constitutes a so-called retard separation mechanism.

The sheet feeding roller 122 is rotationally driven in the conveying direction so as to send out the sheets S stacked and accommodated in the sheet feeding tray, and the separating roller 124 is rotationally driven in the direction for pushing the sheet S back to the sheet feeding tray. It is attached to the shaft 125 via a torque limiter (not shown).

When the leading edge of the sheet S reaches the nip of the sheet feed roller 122 and the separation roller 124, the sheet S is conveyed by the sheet feed roller 122. When only one sheet S is fed to the nip of the paper feed roller 122 and the separation roller 124, the separation roller 124 rotates in the paper conveyance direction according to the paper feed roller 122, but a plurality of sheets S are fed. If the torque limiter returns to the seat S,
Since the frictional force between them is exceeded, the separation roller 124 rotates in the direction to push back the sheet S, and separates the uppermost sheet S in contact with the sheet feeding roller 122 from the rest.

The separating roller shaft 125 has a coaxial 12
A sensor passage plate 132 that rotates together with the sensor 5 is assembled. In addition, the sensor passage plate 132 having a through hole,
The separation roller shaft 125 is mounted so as to surround the outer circumference of the separation roller shaft 125 by the inner circumference of the through hole. Light receiving sensor plate 13
0 is fixed to the main body of the sheet feeding device 30 and has a separation roller shaft 125
It is stationary without depending on the rotation of. The light receiving sensor plate 130 is provided with a light receiving sensor 131 that senses light and outputs a signal according to the amount of light to the control circuit 40. The plate surface of the sensor passage plate 132 is provided with a hole 32a for passing a signal from a light emitting portion (light emitting element) (not shown) to the light receiving sensor.

FIG. 3 is an enlarged plan view showing the plate surface of the light receiving sensor plate 130.

As shown in FIG. 3, the light receiving sensor plate 130
The plate surface is provided with three light receiving sensors.

Each light receiving sensor 31 has a separating roller shaft 125.
When is in a predetermined rotation phase, a signal from the light emitting portion is sensed through the hole 32a. That is, the hole 32
a has a function of changing the amount of light received by the light receiving sensor 31 in accordance with the rotation phase of the separation roller shaft 125. Control circuit 4
0 is the generation timing of the signal output from each light receiving sensor 31 (timing at which the amount of received light increases) or each sensor 3
The rotation speed and the rotation direction of the separation roller shaft 125 can be recognized through the order in which 1 outputs a signal.

Here, the separation roller shaft 125 continues to rotate in the direction opposite to the conveying direction of the sheet S, or does not rotate after the end of its life. The control circuit 40 is
When the separation roller shaft 125 as described above recognizes continuous rotation in the direction opposite to the conveying direction of the sheet S (for example, rotation operation that continues for a preset specified time or more) or rotation stop, the separation roller 124 is detected. Determine the lifespan of.
For example, the control circuit 40 recognizes that the separation roller 124 stops its rotation when the signal output is detected at an arbitrary timing during the operation of the sheet feeding device 30 and thereafter no signal output is detected for 2 seconds or more. , Determine the life of the separation roller 124. When the life of the separation roller 124 is determined, the control circuit 40 turns on a warning lamp (not shown) and notifies the user of the fact.

By accurately ascertaining the life of the separation roller 124 in this manner, the roller 124 can be effectively utilized.

(Second Embodiment) Next, a second embodiment in which the sheet feeding apparatus of the present invention is applied to a sheet feeding apparatus of an image forming apparatus.
The second embodiment will be described focusing on the points different from the first embodiment.

FIG. 4 is a perspective view showing the main structure of the sheet feeding device according to this embodiment. Note that the sheet feeding device 30 ′ shown in FIG. 4 also stacks and stocks sheets as with the sheet feeding device 30 according to the first embodiment (see FIG. 2), and at the same time, stores the sheets. It has a function of supplying to the image forming unit.

In FIG. 4, reference numeral 141 denotes a light receiving sensor. Reference numeral 142 denotes a reflection mirror having different reflection angles.
Each reflection mirror 142 is attached to a reflection mirror plate 143 assembled to the separation roller shaft.

In such a device configuration, the light emitting portion (not shown) has a region (hereinafter, referred to as a broken line) in FIG. 5 (enlarged view).
The reflection mirror 14 emits light toward the irradiation area).
2 passes through this irradiation area as the separation roller shaft rotates. As a result, signals are input to the respective light receiving sensors 141 by the reflecting mirrors having different reflecting angles. The control circuit mounted on the image forming apparatus recognizes the rotation speed and the rotation direction of the separation roller shaft through the generation timing of the signal output by each light receiving sensor (or the order in which each sensor outputs the signal). Then, for example, the control circuit is configured to feed the paper feeding device 3
When the signal output is detected at an arbitrary timing during the operation of 0'and no signal output is detected for 2 seconds or more, it is recognized that the separation roller shaft has stopped rotating, and the life of the separation roller is determined. . When the life of the separation roller is judged, the control circuit, for example, turns on a warning lamp (not shown) and notifies the user of that fact.

In this way, even with the device configuration according to the present embodiment, as in the first embodiment, by accurately grasping the life of the separation roller, it is possible to effectively utilize the roller. be able to.

(Third Embodiment) Next, a third embodiment in which the sheet feeding device of the present invention is applied to a sheet feeding device of an image forming apparatus.
The second embodiment will be described focusing on the points different from the first and second embodiments.

FIG. 6 is a perspective view showing the main structure of the sheet feeding device according to this embodiment. The sheet feeding device 30 ″ shown in FIG. 6 is also the sheet feeding device 30 according to the first embodiment (see FIG. 2) and the sheet feeding device 30 ′ according to the second embodiment (see FIG. 4), it has a function of stacking and storing sheets and supplying the sheets to the image forming unit at an appropriate timing.

In FIG. 6, reference numeral 144 denotes a light receiving sensor. Reference numeral 145 indicates a sensor passage plate. As shown in FIG. 7 (enlarged view), the sensor passage plate 145 is provided with circular holes and oval holes at unequal intervals.

In such a device configuration, the light emitted by the light emitting portion (not shown) passes through the sensor passage plate 145 and is input to the light receiving sensor 144. And for example,
If the light receiving sensor 144 outputs the reset signal at the timing of receiving the irradiation light from the light emitting portion through the oval hole, the waveform of the signal output by the light receiving sensor 144 is
It depends on the direction of rotation. That is, the control circuit installed in the image forming apparatus can recognize the rotation speed and the rotation direction of the separation roller shaft through the generation timing of the signal output by each light receiving sensor (or the order in which each sensor outputs the signal). it can. And for example, the control circuit
When the signal output is detected at any timing during the operation of the sheet feeding device 30 'and no signal output is detected for 2 seconds or more, it is recognized that the separation roller shaft has stopped its rotation, and the life of the separation roller is reached. To judge. When the life of the separation roller is determined, the control circuit turns on a warning light (not shown),
Notify the user accordingly.

In this way, even with the apparatus configuration according to the present embodiment, as in the first and second embodiments, the life of the separation roller can be accurately grasped, and the same can be obtained. It is possible to effectively utilize the rollers.

[0047]

As described above, according to the present invention,
By detecting the rotation direction and the like of the separation roller, it is possible to accurately grasp the life of the separation roller and to effectively utilize the same.

[Brief description of drawings]

FIG. 1 is a side sectional view schematically showing the internal structure of an image forming apparatus (copying machine) incorporating a sheet feeding device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing the main structure of the paper feeding device according to the embodiment.

FIG. 3 is an enlarged plan view showing a plate surface of the light receiving sensor plate according to the embodiment.

FIG. 4 is a perspective view showing a main structure of a sheet feeding device according to a second embodiment of the invention.

FIG. 5 is an enlarged plan view showing the main structure of the sheet feeding device according to the embodiment.

FIG. 6 is a perspective view showing the main structure of a paper feeding device according to a third embodiment of the invention.

FIG. 7 is an enlarged plan view showing the main structure of the paper feeding device according to the embodiment.

FIG. 8 is a schematic diagram showing a main part of a sheet feeding device used in a conventional image forming apparatus.

[Explanation of symbols]

30, 31, 32, 33 Paper feeder 31 Each light receiving sensor 32a hole 40 control circuit 120 paper trays 121 Pickup roller 122 paper feed roller 124 Separation roller 125 separation roller shaft 125 separate drive shaft 130 Light receiving sensor plate 131 Light receiving sensor 132 sensor passage plate 141 Light receiving sensor 142 reflective mirror 143 Reflective mirror plate 144 Light receiving sensor 145 sensor passage plate O manuscript S sheet

Claims (7)

[Claims] 1. A sheet feeding tray for stacking sheet bundles, and a plurality of sheets forming the sheet bundle are brought into contact with a top sheet of the sheet bundles stacked on the sheet feeding tray in a predetermined direction. The sheet feeding means for feeding the sheet in order from the top, the sheet feeding means for abutting the sheet that has been fed out and for transporting the sheet along a predetermined sheet path, and the surface of the sheet that is fed out from the sheet feeding tray. In a sheet feeding device having a separating roller that is abutted toward the conveying means and is driven to rotate so as to push back these overlapping sheets to the sheet feeding tray, a light emitting element that emits light, and a light emitting element that emits light. A light receiving sensor for receiving the light and outputting a signal according to the light amount; and a light receiving amount changing means for changing the light receiving amount of the light receiving sensor according to the rotation phase of the separation roller, A rotation direction detection unit that detects the rotation direction of the separation roller based on the amount of light received by the light reception sensor that is changed; and a life determination unit that determines the life of the separation roller based on the detected rotation direction. A sheet feeding apparatus comprising: 2. The sheet feeding apparatus according to claim 1, wherein the light receiving amount changing unit has a disk provided with at least one hole and rotates together with the separating roller, and the light receiving sensor includes the light emitting element. Receiving the light emitted by the disc through a hole provided in the disc, and the rotation direction detecting means detects the rotation direction of the separation roller based on the timing at which the light receiving sensor receives the light emitted by the light emitting element. A sheet feeding device. 3. The sheet feeding apparatus according to claim 2, wherein a plurality of the holes are provided in the disc at unequal intervals. 4. The sheet feeding apparatus according to claim 1, wherein the light receiving sensor is arranged substantially coaxially with the separating roller. 5. The sheet feeding device according to claim 1, wherein the light receiving amount changing unit has a plurality of mirrors each having a different reflection angle and rotating in synchronization with the separation roller, and each mirror. Is a sheet feeding device, wherein when the separation roller is in a specific rotation phase, the light emitted from the light emitting element is reflected and the light receiving sensor receives the light. 6. The sheet feeding apparatus according to claim 5, wherein the plurality of mirrors are integrated with the separation roller. 7. The sheet feeding device according to claim 1, wherein the life determining unit is configured to rotate the separation roller in a direction opposite to a conveyance direction continuously for a specified number of times or more. Alternatively, the sheet feeding device is characterized in that the life of the separation roller is judged when the stationary state is judged to be longer than a specified time.