JPH03267229A - Dual tray type paper feeding device for picture-image forming device - Google Patents

Abstract

PURPOSE:To keep the feeding condition constant in respective first and second paper- feeding parts, even if the device is applied to a cassette tray or to an elevator tray, by setting the variation widths of the vertical movement of paper-feeding means each of which is in contact with the upper surface of the paper sheet and moves up and down in response to the rise of the bottom plate and to the decrease in the amount of the placed paper sheets, so as to be nearly equal. CONSTITUTION:A first paper-feeding part 21 and a second paper-feeding part 22 are provided with paper-feeding means 25, 29 which are in contact with the upper surfaces of paper sheets and move up and down in response to the rise of the bottom plates 23, 27 and to the decrease in the amount of paper sheets for feeding paper sheets respectively, and the variation widths of the vertical movement of the paper-feeding means 25, 29 are set so as to be nearly equal. Further, paper-sheets end parts are arranged in such a way that the distance between the end of the paper sheet housed in a cassette tray and the paper-sheets manipulating means 33 provided in front of the paper-feeding means 25 is nearly equal to the distance between the end of the paper sheet housed in an elevator tray 8 and the paper sheets manipulating means 33 provided in front of the paper-feeding means 29.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a paper feeding device for an image forming apparatus such as a copying machine equipped with a plurality of trays. The present invention relates to a multi-tray paper feeding lid for an image forming apparatus, which is equipped with an elevator tray that can store paper and whose bottom plate can move up and down to raise and lower the stored paper.

[Conventional technology]

A copying machine in which a large number of paper trays are arranged in multiple stages, and arbitrary paper is sent out from each paper tray through a paper feed path, and the paper is fed toward an image transfer unit such as a photoreceptor drum, Image forming devices such as printers were developed in 1982.
-194634, etc.

Such an image forming apparatus is constructed by combining an upper frame in which a recording section and a paper feeding section with one paper tray are integrally formed, and a lower frame in which a large number of paper trays and an intermediate tray are incorporated. A paper feed path and a return path for guiding the paper vertically are arranged so as to vertically penetrate both sides of the two frames (5). Then, creating regular recording paper by feeding paper from the paper tray,
Transfer the image to the back side of the paper that has already been copied on one side,
It is configured such that any recording paper production mode can be selected, such as creating a double-sided copy or creating a multiple copy by transferring another image to the image side of a sheet that has been copied on one side.

Furthermore, in addition to the normal paper cassette tray, the conventional image forming apparatus described above has a large-capacity tray (referred to as an elevator tray in this book) that can hold a large amount of paper and can be moved up and down while keeping the bottom plate horizontal. has been done.

[Problem to be solved by the invention]

Among these paper trays, the cassette tray moves the paper up and down by swinging the bottom plate, and the elevator tray moves the paper up and down by horizontal movement. 2. Description of the Related Art As current image forming apparatuses become faster and conveyance paths become longer, reliable paper feeding from paper trays is required.

Particularly in the case of multi-stage trays as described above, since the paper conveyance path is different for each tray, it is necessary for each tray to be sent out at a predetermined timing at the first feeding section from the tray. For this reason, dedicated paper feeding devices have been designed and used separately for each tray, particularly for the cassette tray and elevator tray.

An object of the present invention is to provide a paper feeding device that can maintain constant feeding conditions regardless of whether it is applied to a cassette tray or an elevator tray, without requiring a dedicated paper feeding device. be.

[Means to solve the problem]

In order to achieve this object, the present invention provides a first feeder having a vertically movable first bottom plate on which sheets are placed on a cassette tray, and a first bottom plate pushing means for pushing up the bottom plate. a paper section, a vertically movable second bottom plate on which paper is placed on an elevator tray, and pushing up this bottom plate;
2 bottom plate pushing means'! J2 paper feeding unit, the paper feeding device feeds paper by selecting from the first paper feeding unit and the second paper feeding unit, the first paper feeding unit and the second paper feeding unit
Each of the paper feeding sections is provided with a paper feeding means that contacts the top surface of the paper and moves up and down to feed and press the paper as the bottom plate rises and the amount of paper decreases. The distance between the leading edge of the paper stored in the cassette tray and the paper handling means provided in front of the paper feeding means, and the distance between the leading edge of the paper stored in the elevator tray and the front of the paper feeding means are set to be approximately the same. There is provided a paper feeding device for an image forming apparatus, characterized in that the leading edge of the paper is arranged so that the distance from the paper handling means provided at the front end of the paper is approximately the same.

Embodiment The configuration of an image forming apparatus to which the present invention is applied will be explained according to the illustrated example.

The embodiment shown in FIG. 1 shows a case where the image forming apparatus 1 of the present invention is a copying machine. , mainly the paper feed section! It consists of a lower device 3 equipped with.

In the image forming apparatus l of the present invention, the upper loader f2 is provided with a platen 4 at the top, as in the case of a general copying machine, and a document is placed on this platen to obtain a predetermined copy from the document. A control panel is provided for selecting the copying mode, setting the number of copies, and performing other scanning operations.

As shown in FIG. 1, the copying machine according to the present invention is provided with a plurality of paper trays 5, 6, 7, 8 and 9 stacked vertically, and from each paper tray, It is constructed so that the paper can be fed 8 arbitrarily.

In the copying machine described above, the upper device 2 is provided with an optical device 10 for reading an image, a photoreceptor drum 11, and various mechanisms such as a developing device 12 and a transfer device 13 around the photoreceptor drum. , a paper tray 5, and a paper transport device 114 arranged corresponding to the paper tray.

Further, in the lower device 3, a plurality of paper trays 6 to 9 are arranged one on top of the other in the vertical direction, and a paper feeding device unit 15 is installed in the paper feeding section of each paper tray.

Note that the paper tray provided in the copying machine of the present invention is configured as a so-called front loading type device that can be inserted and removed from the front part of the main body frame, and one of the paper trays is The paper feeder unit is configured to feed paper from the side. Further, on both sides of the upper and lower devices 2 and 3, there is a paper conveyance path 16 that passes through these devices in the upper and lower directions for feeding the paper from the paper tray toward the recording section, and a single-sided copying path. a paper return path 17 for transporting the paper to the intermediate tray 9 provided in the lower device 3;
and is provided.

In the lower device 3, an intermediate tray 9 is disposed between the paper trays 7 and 8, and the single-sided copied paper is returned to the intermediate tray 9, and the image is transferred again via the paper feeder unit 15. A desired copying mode, such as multiple copying or double-sided copying, can be selected by sending the copy toward the copying section.

In the illustrated embodiment of the present invention, the lowest paper tray 8 is configured as an elevator tray that can accommodate a large amount of paper and whose bottom plate can move up and down to raise and lower the stored paper. At the bottom of the large-capacity tray, there are casters 18 for supporting the tip of the tray 8 when the tray 8 is bent out.
Located outside. The casters 18 also function to prevent the weight of the elevator tray 8 from being added to the main body frame when the elevator tray 8 is pulled out.

FIG. 2 shows a multi-tray type paper feeder according to the present invention, and the upper part, that is, the first paper feeder 21 is the cassette tray type paper feeder used for trays 5 to 7 in FIG. Yes, there is a second paper feeder at the bottom! Reference numeral 22 indicates an elevator tray type paper feeding device used in the elevator tray 8 of FIG.

In the upper part, that is, the first paper feeder 21, the first bottom plate 2
3 is swingably provided on the paper cassette tray 24. The bottom plate 23 is rotated clockwise by a first bottom plate push-up means 26 attached to the first paper feed section 25 as the number of sheets decreases. In the second paper feeding device 22, the second bottom plate 27 is provided on the elevator tray 8 so as to be movable up and down in a horizontal state, and is moved upward by the second bottom plate pushing means 28 as the number of sheets decreases.

Similar to the paper feeding section 25 of the first paper feeding device 21, the ¥fJ2 paper feeding device 22 is also provided with a paper feeding section 29 as a second paper feeding section. These paper feeding sections 25 and 29 are each provided with a paper feeding means 40 having the same configuration, and these paper feeding means are set so that the fluctuation ranges H1 and H2 of their respective vertical movements are the same.

Also, the distance D1 between the leading edge of the paper 32 housed in the cassette tray 24 and its paper handling means 33, and the distance D1 between the leading edge of the paper 32 housed in the elevator tray 8 and the paper handling means &
33 and the distance D2 is the same.

In order to maintain the distance D2 and D2 at the same length with high precision, on the upper cassette tray type paper feeder 21 side, the rail 35 of the frame that supports the cassette 24 so as to be freely drawn out must be attached to the device main body frame 36. The position of the paper feed section 250 should be set with high accuracy P, and on the side of the first paper feed section 25, the paper feed section 250 should be attached to the main body frame 36 with high precision. In addition, on the side of the lower elevator tray type paper feeder 22, the rollers 37 that support the elevator tray 8 so that it can be freely drawn out and the rails 38 attached to the main body frame 36 are accurately attached to prevent horizontal wobbling. Also, as described above, on the second paper feed section 29 side, the paper feed section 290 must be attached to the main body frame 36 with high precision.

Next, the paper feeding section 25 of the first paper feeding device 21 and the second paper feeding device [
The mechanism of the paper feed section 29 of No. 22 is the second! ! Outside of I, the 31st
! The explanation will be given with reference to the drawings after I.

In addition, both paper feeds! Comparing s25 and 29 with each other, the first
A first bottom plate push-up means 26 is attached to the paper feed section 25, and a second
The paper feed R25 is different in that 1i; 2 bottom plate pusher &28 is attached, but the other configurations are the same. Therefore, the first paper feed section 25 will be explained, and each component and member of the second paper feed i29 will be given the same reference numeral and the explanation thereof will be replaced. Further, the first push-up means 26 will be described later using FIG. 7.

The paper feeding means 40 of the paper feeding section includes a paper feeding roller 41 and a roller 4.
1, and the support member 42 is rotatably supported around a drive shaft 43. This support member 42 is a spring 44
is urged to swing downward, that is, in the direction of the paper surface. The paper fed by the paper feed roller 41 is processed by the sorting means 33 to prevent the feeding of two or more sheets, that is, double feeding. This sorting means 33 consists of a retard roller 46 and a feed roller 47, and both rollers can move toward and away from each other, and are separated when there is no paper. In the paper feeding state, both rollers are in contact with each other and are driven to rotate in opposite directions. Therefore, the power from the drive gear 48 (left side in FIG. 4) of the drive motor (not shown) is transmitted to the gears 49 to 54, the electromagnetic clutch 55, and the drive shaft 43 described above, and rotates the feed roller 47. do. This rotation is transmitted to the paper feed roller 41 via another gear 56, 57, 58, so that the paper feed roller 41 and the feed roller 47 are configured to rotate in conjunction with each other.

The support member 42 of the paper feed roller 41 is configured as shown in FIG. 6, and is urged to rotate downward by the spring 44 as described above.
A pin 60 provided on the lever 62 of the push-up member 61 is placed on the lever 62 of the push-up member 61. This push-up member 61 is rotatably provided in the paper feed section, is biased by a tension spring 63, and is rotated by a solenoid 64 in a direction opposite to the biasing direction. Also, Tluid 6
4 is in operation during paper feeding, the push-up member 61 rotates and the lever 62 retreats downward. Therefore, the support member 42 is rotated by the spring 44 about the drive shaft 43, and the paper feed roller 41 is pushed to the lowest position.

An actuator 66 for a photosensor 65 is provided on the support member 42, and the photosensor 65 is turned on when the paper feed roller 41 is at the lowest position. Of course, when the number of sheets decreases and the paper feed roller 41 drops by a certain amount (3 mm in this embodiment), the photo sensor 65 turns on and the first bottom plate push-up means 26 (push-up means for cassette tray type paper feed device) is activated. and second bottom plate push-up means 28 (
A signal is generated to raise the pusher &) for the elevator tray type paper feeder.

2nd bottom plate pusher & 28 for elevator tray type paper feeder
As shown in FIG. 2, these are of a winding type using a motor 67, and are provided at four locations on the bottom plate to raise the bottom plate 27 while keeping it in a horizontal position.

In addition, the bottom plate pushing means 2 of the cassette tray type paper feeding device [21]
6 is illustrated in detail in FIG.

In the bottom plate push-up means 26 shown in FIG. 9J7, reference numeral 68 is a tag that directly contacts the bottom plate 23 to push up the bottom plate 23, and is attached to one end of a shaft 69.

A segment gear 70 is fixed to the other end of the shaft 69.
It is urged in the direction of the arrow by a spring 71.

Segment gear 70 is connected to rotary input gear 76 via gears 72, 73, 74 and electromagnetic clutch 75. Further, a gear 77 movable in the direction of the arrow is provided, and can be freely engaged with and disengaged from the gear 74. This gear 77 is biased by a bow spring 78 to maintain a separate state from the gear 74, and when the cassette tray 24 is inserted, a part of the tray 24 presses the support member 79, and the gear 77 is adapted to engage with gear 74. Furthermore, the gear 77 is attached to its shaft 80 via a one-way bearing (not shown), and when engaged with the gear 74, the tag 68 is raised but not lowered.

This bottom plate push-up means 26 is attached to the paper feed section 25, as shown in FIG. The rotation input gear 7 described above
6 is engaged with a gear 49 shown in FIGS. 4 and 5.

Each member of the bottom plate push-up means 26 described above is configured to be integrally attached to and detachable from the paper feed section 25.

As shown in FIG. 5, the glue roller 46 of the handling means 33 is connected to a drive shaft 83 via a torque limiter 82, and the drive shaft 83 is connected to a gear via several gears (not shown). 54.

In FIG. 3, the reference numeral 84 is attached to a drive roller 86 (driving roller, with which a pinch roller 85 is in contact. The pinch roller 85 forms a conveyance path) 86 that guides the sent out paper to a conveyance path. The chute 86 is attached to an opening/closing door 87 of the copying machine. Note that numerals 88 and 89 are chutes attached to the paper feed section 25 (29), respectively.

Reference numeral 90 in FIG. 5 is a mechanism for separating the retard roller 46 from the feed roller 47, and the cassette tray 2
4 or by inserting and removing the elevator tray 8 into the main body. Each tray is formed with a protrusion (for example, please refer to the protrusion 91 of the elevator tray 8 in Figure 2!), and this protrusion is used to feed paper! By suppressing and moving the actuating piece protruding from 25 (29), the lever 92 shown in FIG. Rotate to
The retard roller 46 comes into contact with the feed roller 47). Therefore, when the cassette tray 24 or the elevator tray 8 is pulled out, the retard roller 46 is separated from the feed roller 47. This means that both rollers 46 and 4
This is to prevent the paper from being damaged even if the paper is caught between the holes 7.

Next, a series of operations will be explained.

Since the operations of the elevator tray 8 and the cassette tray 24 are almost the same, the operation of the paper feeder 21 on the cassette tray 24 side will be explained. By inserting the tray,
Gear 77 in FIG. 7 engages gear 74. At the same time, the retard roller 46 rises and comes into contact with the feed roller 47.

Further, a switch of a paper size detection device (not shown) is activated, and the solenoid 64 shown in FIG. 6 is energized by the signal.

The paper feed roller 41 descends to the lowest position, and (1) the sensor 65 turns on. This causes the electromagnetic clutch 75 in FIG. 7 to be energized.

At point 2, the drive gear 48 in FIG. 4 is already rotating, and the segment gear 70 is also rotating, moving the tag 68 upward and pushing up the bottom plate 23. At this time, since the gear 77 is provided with a one-way bearing, it will not descend due to the weight of the paper.

When the bottom plate 23 is pushed up, the paper feed roller 41 comes into contact with the upper surface of the paper, and the paper feed roller 41 is further pushed up by the upward movement of the paper surface, the actuator 66 shown in FIG. 6 turns off the photosensor 65. As a result, the electromagnetic clutch 75
is shut off and the paper stops rising.

When the copy start button is pressed and a paper feed signal is output, the paper feed electromagnetic clutch 55 (Fig. 5) is turned on, and the feed roller 47 and retard roller 46 (torque limiter 82) driven by the feed roller 47 are turned on.
(is slipping) and the paper feed roller 41 rotate at the same time, and only one sheet of paper is sent out by the paper feed slot roller 41 and passes through the feed roller 47 and retard roller 46, and both rollers also have a feeding action. ) and are guided to the paper transport path.

If two or more sheets of paper are sent out from the paper feed roller 41, the lower paper (on the retard roller side) is prevented from advancing by the action of the torque limiter 82 of the retard roller 46, and the upper paper (on the feed roller side) Only one sheet of paper passes through. This means that the torque limiter 82 is
The torque is set to be smaller than the frictional force between the roller 47 and the paper and the roller 46, and larger than the frictional force between the paper and the paper, so when multiple papers arrive, the torque is set to be smaller than the frictional force between the paper and the roller 46. This is because the set torque of the limiter is overcome and the retard roller 46 is rotated in the direction of returning the paper by the rotation of the drive shaft 830.

That is, the paper handling means 33 prevents the second and subsequent sheets from advancing.

As the paper is fed out and the remaining amount of paper decreases, the paper feed roller 41 descends under the action of the spring 440, and when it descends a certain length, the photo sensor 65 turns on, and this signal activates the electromagnetic clutch. 75 is energized for a certain period of time by a timer, and when the photosensor 65 is turned off, the paper stops rising. In this way, by combining the photosensor and the timer, the range of fluctuation in the vertical movement of the paper feed roller 41 can be kept constant within a narrow range. That is, the timer compensates for poor response of the photosensor.

Note that the subsequent operation is a repetition of the above-described operation, and as described above, the same applies to the operation of the elevator tray. Therefore, please refer to the above description.

Effects of the Invention According to the present invention, the present invention includes a first paper feeding section on the side of the paper cassette tray and a second paper feeding section on the side of the elevator tray. According to the paper feeding device that feeds paper, each of the first paper feeding section and the second paper feeding section contacts the top surface of the paper and moves up and down in response to the rise of the bottom plate and the decrease in the amount of paper loaded. It has a paper feeding means for sending out the paper, and is set so that the width of vertical movement of the paper feeding means is approximately the same, and
The distance between the leading edge of the paper stored in the cassette tray and the paper handling means provided in front of the paper feeding means, and the distance between the leading edge of the paper stored in the elevator tray and the paper handling means provided in front of the paper feeding means. Since the leading edge of the paper is arranged so that it is approximately the same, even in the case of a multi-tiered tray consisting of various trays, and especially in the case of a cassette tray and an elevator tray, separate dedicated paper feeds are required. design equipment,
Eliminates the inconvenience of using a dedicated paper feeding device. Furthermore, since the range of fluctuation is constant as described above, there is an advantage that paper feeding time can be shortened by reducing the range of fluctuation.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a copying machine suitable for applying the paper feed device according to the present invention, FIG. 2 is a partial side sectional view showing the paper feed device according to the present invention, and FIG. 3 is a cassette FIG. 4 is a plan view of the paper feeding section in FIG. 3, FIG. 5 is a sectional view taken along the line ■-■ in FIG. 3, and FIG. ,
FIG. 7 is a perspective view showing the paper feed roller including its surroundings.
FIG. 6 is a perspective view of moistening the bottom plate pushing means of the cassette tray type paper feeder. Explanation of symbols 1... Copy machine 2... Upper device 3... Lower device 4... Platen 5-7... Cassette tray 8 ...Elevator tray 9 ...Intermediate tray 11 ...Photosensitive drum 12 ...Development device 21 ...Cassette tray type paper feed device 22・
...Elevator tray type paper feed installation 23.27...
...Bottom plate 24...Cassette 25.29
...Paper feeding device 26.28...Bottom plate push-up means 33...Separating means 40...Paper feeding means 41...Paper feeding roller 46...Glue tar roller 47...
...Feeding roller of sorting means Fig. 1 Fig. 3 Fig. 6 Fig. 4

Claims (1)

[Scope of Claims] A first paper feeding unit having a vertically movable first bottom plate on which paper is placed on a paper cassette tray, and a first bottom plate pushing means provided on the main body to push up the bottom plate. and a second paper feeding unit having a vertically movable second bottom plate for placing paper provided on an elevator tray, and second bottom plate pushing means for pushing up this bottom plate, In the paper feeding device that selectively feeds paper from a first paper feeding section and a second paper feeding section, the first paper feeding section and the second paper feeding section each have a mechanism that contacts the top surface of the paper and causes the bottom plate to rise. A paper feeding means is provided that moves up and down to send out the paper in response to a decrease in the amount of paper being placed, and the range of fluctuation of the up and down movement of the paper feeding means is set to be approximately the same, and the amount of paper stored in the cassette tray is set to be approximately the same. The distance between the leading edge of the paper and the paper handling means provided in front of the paper feeding means is approximately the same as the distance between the leading edge of the paper stored in the elevator tray and the paper handling means provided in front of the paper feeding means. A paper feeding device for an image forming apparatus, characterized in that a leading edge of paper is arranged.