JPH05201562A - Multi-stage paper feed device - Google Patents

Abstract

PURPOSE:To eliminate any difference in sheet conveying speed between paper feed tray units so as to prevent occurrence of several troubles by rotating all pull-out rollers in the units at an equal speed. CONSTITUTION:The rotation of a sheet conveying motor 40 is transmitted through a gear train to a pull-out roller 35 so as to rotate a driven shaft 67 through a timing belt 70. Then, the rotation of a paper feed tray unit 30 at a high speed is transmitted to that at a low speed through the meshing between drive and driven gears 65, 66. Further, due to the provision of a one-way clutch 76, the rotation of the tray unit 30 at a low speed is increased to that at a high speed, and accordingly, all pull-out rollers in both units 30 are rotated at an equal speed. Accordingly, an electromagnetic clutch 75 in the unit 30 in which sheets are loaded, and the sheets are successively conveyed by the pull-out rollers 35, 36 so that the sheets are fed out one by one through a transverse passage in the upper stage tray unit 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a printer, a copying machine,
It can be applied to a sheet processing apparatus such as a facsimile and a printing machine. More specifically, the present invention relates to such a sheet processing apparatus, for example, a multi-stage sheet feeding apparatus in which the processing apparatus main body is mounted and various sheets are appropriately and selectively supplied.

Conventionally, in this type of multi-stage sheet feeding device, a plurality of sheet feeding tray units each having a vertical passage are provided with a sheet feeding tray, a sheet feeding roller and a pull-out roller, and the sheet feeding tray of each unit is provided with, for example, The sheets of different sizes are accommodated and the units are provided in multiple stages, and the rotation of the drive motor of the processing apparatus main body can be transmitted to the paper feed roller and the pullout roller of each unit.

Then, the rotation of the drive motor is transmitted to rotate the paper feed roller of the one paper feed tray unit, and a sheet of an appropriate size is fed out and conveyed by the pullout roller, and is fed out through the vertical passage of the upper unit. ..

However, in order to be able to use such a multi-stage paper feeder, the drive motor of the main body of the processor must be large, which increases the cost. Further, when the multi-stage paper feeding device is not attached, an unnecessarily large drive motor is used, which is uneconomical.

Therefore, in the conventional multi-stage sheet feeding device, a sheet conveying motor is individually attached to each sheet feeding tray unit, and the rotation of the motor is transmitted to a sheet feeding roller or a pullout roller through a gear train. In some cases, each of them is rotated by an individual sheet conveying motor instead of the drive motor of the main body of the processing apparatus.

However, in such a multi-stage sheet feeding device, the sheet conveying speed of each sheet feeding tray unit becomes different due to the dimensional accuracy of each component and the variation in performance, so that the sheet conveying becomes unstable and various kinds of sheets are conveyed. There was a problem that caused trouble.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the difference in the sheet conveying speed between the sheet feeding tray units, stabilize the sheet conveying, and prevent various troubles from occurring.

[0008]

Therefore, what is stated in claim 1 is, for example, as shown in the following illustrated embodiment,
A sheet feed tray 31 that stores sheets S, a sheet conveying motor 40, and a gear train G that transmits the rotation of the motor 40.
And a feed roller 33 and pull-out rollers 45 and 36 for transmitting the rotation of the motor 40 via the gear train G.
And the sheet feed tray units 30 each having a vertical passage 32 are provided in multiple stages, and the sheets S in the sheet feed tray 31 are fed out by the sheet feed rollers 33 to pull out the rollers 35.3.
In the multi-stage sheet feeding device P which is conveyed by 6 and is sent out through the vertical passage 32 of the upper sheet feeding tray unit 30, a drive gear which is fixed on the roller shaft 35a of the pullout roller 35 in each sheet feeding tray unit 30. 65
And a driven shaft 67 that is urged in one direction so as to be movable in parallel.
And a driven gear 69 rotatably provided on the driven shaft 67.
And a timing belt 70 which is tensioned by a biasing force applied to the driven shaft 67 by being stretched between the roller shaft 35a of the pull-out roller 35 and the driven shaft 67.
And a one-way clutch 76 provided between the roller shaft 35a of the pull-out roller 35 and the gear train G,
The driven gear 69 of the upper sheet feeding tray unit 30
Is meshed with the drive gear 65 of the lower stage.

According to a second aspect of the present invention, for example, as shown in the following illustrated embodiment, in the multi-stage sheet feeding device P according to the first aspect, the driven shaft 67 is supported by a lever 71,
The lever 71 is rotatably provided, and is biased by a biasing member such as a torsion spring 73 to apply tension to the timing belt 70.

According to a third aspect of the present invention, for example, as shown in the following illustrated embodiment, a sheet feed tray 31 for storing sheets S, a sheet conveying motor 40, and a gear train G for transmitting the rotation of the motor 40. And a plurality of paper feed tray units 30 each having a paper feed roller 33 and pull-out rollers 35 and 36 for transmitting the rotation of the motor 40 via the gear train G, and a vertical passage 32.
In the multi-stage sheet feeding device P ′ that feeds out the sheet S in the sheet feeding roller 33, conveys it by the pull-out rollers 35 and 36, and feeds it through the vertical passage 32 of the sheet feeding tray unit 30 in the upper stage, for example, in the upper stage. A detection unit such as a sensor 80 for detecting the sheet S after passing through the pull-out rollers 35 and 36, and driving of the sheet conveyance motor 40 of the lower sheet feed tray unit 30 when the sheet S is detected by the detection unit. It is characterized by comprising a control means for stopping and a clutch means 81 for interrupting the rotation transmission from the pull-out roller 35 in the lower stage to the sheet conveying motor 40.

[0011]

According to the first aspect of the invention, the sheet S
When feeding the sheet, all sheet conveying motors 40 are driven. Then, the rotation of the motor is transmitted to the pullout roller 35 via the gear train G. Then, the driven shaft 67 is rotated via the timing belt 70. Then,
The rotation of the earlier paper feed tray unit 30 is transmitted to that of the slower paper feed tray unit 30 through the engagement between the drive gear 65 and the driven gear 69. Due to the presence of the one-way clutch 76, the rotation of the slower paper feed tray unit 30 is adjusted to the rotation of the faster paper feed tray unit 30 regardless of the rotation speed of the slower paper feed tray unit 30. All 30 pullout rollers 35 rotate at equal speed. Therefore, the paper feed tray unit 3 that stores the corresponding sheet S
The electromagnetic clutch 75 of 0 is turned on. Then, the sheet S of the corresponding size is sent out, and the pullout rollers 35.3
The sheet is conveyed by 6 and is sequentially sent out through the vertical passage 32 of the upper sheet feeding tray unit 30.

According to the second aspect of the invention, tension is applied to the timing belt 70 by the urging force of the lever 71.

According to the third aspect of the present invention, when the sheet S is sent out, when the detecting means detects the sheet S after passing through the upper pull-out rollers 35 and 36, the control means causes the lower sheet feeding tray unit 30 to be detected. Sheet conveying motor 4
Stop driving 0. Then, the sheet S is conveyed at a constant speed through the vertical passage 32 by the upper pull-out rollers 35 and 36. At that time, the clutch means 81 functions to cut off the rotation transmission from the pull-out roller 35 of the lower sheet feeding tray unit 30 to the lower sheet conveying motor 40.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 shows a case where a multi-stage sheet feeding device according to an embodiment of the present invention is applied to a printer, and is a schematic configuration diagram of a laser printer in which an apparatus main body is placed on the multi-stage sheet feeding device according to the present invention. Reference numeral 10 in the figure denotes the apparatus main body. The apparatus body 10 is placed on the box-shaped case 11 of the multi-stage sheet feeding apparatus P. A belt-shaped photosensitive member 12 is provided in the main body 10 of the apparatus at substantially the center thereof. Around the photosensitive member 12, the charger 1 is sequentially arranged in the driving direction indicated by the arrow in FIG.
3, a developing device 14, a transfer device 15, and a cleaning device 16 are arranged. An optical writer 17 is arranged above the charger 13 and the cleaner 16.

Further, a unit accommodating portion 10a is formed below the transfer device 15, and a main body paper feed tray unit 18 is arranged in the unit accommodating portion 10a. The main body paper feed tray unit 18 includes a paper feed tray 19 that stores sheets S.
A vertical passage 20 through which the sheet S passes is provided at the right end of the paper feed tray 19 in the drawing, and a paper feed roller 21 is provided at the upper right side. As shown in FIG. 3, a bottom plate 22 on which sheets S are stacked is rotatably provided in the paper feed tray 19, and a push-up member 23 is rotatably provided below the bottom plate 22.
Then, the push-up member 23 is appropriately biased by the biasing means to push up the bottom plate 22, and the leading end of the uppermost sheet S is pressed against the paper feed roller 21. Friction pads 24 for separating sheets are pressed against the paper feed rollers 21, respectively. The main body paper feed tray unit 18 is provided with a paper feed roller 21.
The rotation of a main body drive motor (not shown) in the apparatus main body 10 is transmitted to the roller shaft 21a so as to be freely rotatable.

Then, an electromagnetic clutch (not shown) is turned on to rotate the paper feed roller 21, and the sheet S is fed out from the paper feed tray 19 and fed in the direction A in FIG.
Stop it by hitting the registration roller 25 inside. Then, the photosensitive drum 1 is timed by the registration roller 25.
2 is conveyed to the lower side. The photoconductor 12 is driven in the clockwise direction in the figure, and at that time, the surface thereof is uniformly charged by the charger 13, and the laser beam L from the optical writing device 17 is irradiated to the photoconductor 12 to form an electrostatic latent image. To form. This latent image is developed by the developing device 14.
When passing through the position, toner is attached and a visible image is formed. Then, this visible image is transferred onto the upper surface of the sheet S by the transfer device 15. After the image transfer, the sheet S is conveyed to the fixing device 26, and the transfer image is fixed by the fixing device 26. Fixing device 26
The sheet S that has exited is further conveyed by the sheet ejection roller 27 and ejected in the direction of arrow B or C in FIG.

On the other hand, the surface of the photoreceptor 12 after image transfer is
The cleaning device 16 performs cleaning to remove the residual toner, and then the static eliminator 28 removes the charge.

By the way, the above-described multi-stage sheet feeding device P of the present invention is constructed in detail as follows. First, as shown in FIG. 3, the unit housing portions 11a and 11a are formed in the box-shaped case 11 in two upper and lower stages. Then, the paper feed tray units 30 having the same structure are arranged in the respective unit storages 11a and 11a. The paper feed tray unit 30 includes a paper feed tray 31 that stores sheets S,
A vertical passage 32 is provided at the right end of the paper feed tray 31 in the figure,
A paper feed roller 33 is provided on the upper right side. Further, the bottom plate 22 and the push-up plate 2 similar to the main body paper feed tray unit 18 described above.
3. A friction pad 24 is provided.

Further, the paper feed tray unit 30 is provided with pullout rollers 35 and 36 above the vertical passage 32. The driven pull-out roller 36 is pressed against the drive-side pull-out roller 35 by urging the roller shaft 36a with the compression spring 37. Therefore, as shown in FIGS. 2 and 1, a dedicated sheet conveying motor 40 is provided in the unit housing portion 11a.
Drive the paper feed roller 33 and pull-out rollers 35, 36
Is configured to rotate.

Further, the paper feed tray unit 30 is provided with a drive mechanism as shown in more detail in FIGS. That is, the sheet conveying motor 40 has the motor shaft 40.
A worm gear 50 is provided on a and is supported by a bracket 51. The worm gear 50 meshes with a gear 57 fixed to one end of a gear shaft 57a. The gear 57 is a coaxial gear 58.
And meshes with the gear 59 on the gear shaft 59a. Gear 5
Reference numeral 9 denotes a gear 60 provided on the roller shaft 33a of the paper feed roller 33.
Mesh with. The gear 60 meshes with the gear 61 on the gear shaft 61a. The gear 61 meshes with a gear 62 provided on the roller shaft 35a of the drive-side pullout roller 35. The gear train from the worm gear 50 to the gear 62 forms a gear train G.

Further, in the paper feed tray unit 30, the drive gear 65 and the belt gear 66 outside thereof are fixed to one end of the drive side roller shaft 35a. Further, a driven shaft 67 is movably provided in parallel with the driving-side roller shaft 35a, a belt gear 68 is fixed to one end of the driven shaft 67, and a driven gear 69 is rotatably provided at the other end. Then, the timing belt 70 is stretched between the belt gears 66 and 68.
The driven shaft 67 is connected at its other end to a connecting shaft 71 a provided on one side of the lever 71 and supported by the lever 71. The levers 71 are rotatably attached in the unit housing portion 11a through the pins 72 on the other side. Then, the torsion spring 73 (biasing member) having one end hooked on the unit housing portion 11a and the other end hooked on the lever 71 is wound around the pin 72. Then, the torsion spring 73 urges the lever 71 to rotate, and the driven shaft 67 is urged downward in the drawing parallel to the roller shaft 35a via the lever 71. Then, tension is applied to the timing belt 70 by the urging force.

Furthermore, the paper feed tray unit 30 is
As shown in FIGS. 1 and 2, the roller shaft 3 of the paper feed roller 33.
An electromagnetic clutch 75 is provided on the roller 3a between the roller shaft 33a and the gear 60, and the electromagnetic clutch 75 is appropriately disconnected to control the rotation of the paper feed roller 33. Further, on the roller shaft 35a of the drive-side pullout roller 35, a one-way clutch 76 as shown in FIG. 5 is integrally provided with the gear 62 between the roller shaft 35a and the gear 62. Then, the one-way clutch 76, as shown in FIG.
The rotation direction is regulated in one direction so that the sheet S fed out in (1) is conveyed in the conveying direction (arrow C direction).

Therefore, in the illustrated multi-stage sheet feeding device P, when the two sheet feeding tray units 30 are arranged in the unit accommodating portions 11a, 11a of the box-shaped case 11 and attached vertically, as shown in FIG. , The upper driven gear 69 meshes with the lower drive gear 65 by the urging force of the lower lever 71. In that case, when the teeth of the driven gear 69 and the drive gear 65 abut, the tension of the timing belt 70 causes the driven gear 69 to escape upward in the drawing to facilitate meshing with the drive gear 65. It should be noted that the upper and lower paper feed trays 31 accommodate, for example, sheets S of different sizes.

In the above-described multi-stage sheet feeding device P, when the sheet S in the multi-stage sheet feeding device P is fed into the apparatus main body 10, first, all the sheet conveying motors 40 are driven. Then, the rotation of the motor 40 is transmitted to the pull-out roller 45 via the gear train G. Then, the driven shaft 67 is rotated via the timing belt 70. Then,
The rotation of the earlier paper feed tray unit 30 is transmitted to that of the slower paper feed tray unit 30 through the engagement between the drive gear 65 and the driven gear 69. Due to the presence of the one-way clutch 76, the rotation of the slower paper feed tray unit 30 is adjusted to the faster rotation regardless of the rotation speed of the slower paper feed tray unit 30, and each of the paper feed tray units 30 is rotated. All pullout rollers 45 rotate at equal speed.

Therefore, for example, when the relevant sheet S is sent from the lower sheet feeding tray unit 30, the electromagnetic clutch 75 of the lower sheet feeding tray unit 30 is turned on. Then, the sheet S of the corresponding size is sent out, conveyed by the pull-out roller 45 through the vertical passage 32 of the upper sheet feeding tray unit 30, and sent out through the vertical passage 20 of the main body sheet feeding tray unit 18.

At the time of this sheet feeding, for example, the sheet S fed out by the lower sheet feeding roller 33 is the vertical passage 20.
When jammed at 32, as shown in FIG. 3, if the jammed sheet S is pulled in the conveyance C direction, the pullout rollers 35 and 36 respectively rotate accordingly, so that the jammed sheet S can be easily taken out. it can.

Next, the present invention can be configured as in the following embodiments instead of the illustrated embodiments described above. FIG. 6 shows a multi-stage sheet feeding device P'which is another embodiment of the present invention, and parts corresponding to the respective parts of the multi-stage sheet feeding device P shown in FIG.

In this multi-stage sheet feeding device P ', a sensor (detection means) 80 for detecting that the front end of the sheet S fed out by the lower sheet feeding roller 33 has passed through the upper pull-out roller 35 is provided. It is arranged near the pullout roller 35. The sensor 80 is electrically connected to a control unit (not shown) that stops the driving of the lower sheet conveying motor 40 when the sheet S after passing is detected. Further, on the roller shaft 35a of the lower drive-side pull-out roller 35, clutch means 81 such as a one-way clutch for blocking rotation transmission from the roller shaft 35a to the sheet conveying motor 40 is provided.

In the multi-stage sheet feeding device P ', similarly to the above, when the sheet conveying motor 40 is driven to feed the sheet S from the lower sheet feeding tray unit 30, for example, the upper pull-out roller 35. When the sensor 80 detects the sheet S that has passed through the gap 36, the control means is operated based on the detection signal to stop the driving of the lower sheet conveying motor 40. Then, the sheet S is sequentially conveyed at a constant speed through the vertical passages 20 and 32 by the upper pull-out roller 35. At that time, the clutch means 81
By this action, the rotation transmission from the pull-out roller 35 of the lower sheet feeding tray unit 30 to the sheet conveying motor 40 is cut off.

In each of the above illustrated embodiments, the paper feed tray units 30 are provided in two stages in the box-shaped case 11, but it is also possible to provide them in two or more stages.

[0031]

Therefore, according to the first aspect of the present invention, in a multi-stage sheet feeding device having a multi-stage sheet feeding tray unit having a dedicated sheet conveying motor and a pullout roller rotated by the motor, The one-way clutch connects the paper feed tray units so that rotation can be transmitted, and the one-way clutch allows the rotation of the slower paper feed tray unit to rotate regardless of the rotation speed of the slower paper feed tray unit. All pull-out rollers of each paper feed tray unit rotate at the same speed according to the rotation, eliminating the difference in the paper transport speed of each paper feed tray unit to stabilize the transport of the sheet and prevent various troubles. can do.

According to the second aspect of the present invention, when the driven gear of the upper sheet feeding tray unit and the driving gear of the lower sheet feeding tray unit are meshed with each other, the teeth of the driven gear and the driving gear may abut against each other. By the tension of the timing belt, one driven gear can be released to facilitate meshing with the other drive gear.

According to the third aspect of the present invention, when the detecting means detects the sheet after passing through the pull-out roller, the control means stops the driving of the sheet conveying motor of the lower paper feeding tray unit, and the upper paper feeding. Since the pullout roller is rotated only by the sheet transport motor of the tray unit to transport the sheet, the difference in the transport speed of the sheet of each paper feed tray unit is eliminated to stabilize the transport of the sheet and prevent various troubles from occurring. be able to.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a drive mechanism of a multi-stage sheet feeding device according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view thereof.

FIG. 3 is a configuration diagram showing an internal structure of the multi-stage sheet feeding device.

FIG. 4 is a schematic configuration diagram of a laser printer including the multi-stage sheet feeding device.

FIG. 5 is a cross-sectional view of a one-way clutch in the multi-stage sheet feeding device.

FIG. 6 is a configuration diagram of a drive mechanism of a multi-stage sheet feeding device according to another embodiment of the present invention.

[Explanation of symbols]

 30 Paper Feed Tray Unit 31 Paper Feed Tray 32 Vertical Passage 33 Paper Feed Rollers 35/36 Pullout Rollers 35a / 36a Roller Shaft 40 Sheet Conveying Motor 65 Drive Gear 67 Driven Shaft 69 Driven Gear 70 Timing Belt 71 Lever 73 Torsion Spring Member) 76 One-way clutch 80 Sensor (detection means) 81 Clutch means G Gear train P / P 'Multi-stage paper feeder S Sheet

Claims (3)

[Claims] 1. A sheet feeding tray for storing sheets, a sheet conveying motor, and a gear train for transmitting rotation of the motor.
A multi-staged paper feed tray unit having a paper feed roller and pull-out roller for transmitting the rotation of the motor through the gear train and a vertical passage is provided, and the sheets in the paper feed tray are fed out by the paper feed roller. In a multi-stage sheet feeding device that conveys by the pullout roller and feeds through the vertical passage of the sheet feeding tray unit in the upper stage, a drive gear that is fixed on the roller shaft of the pullout roller in each sheet feeding tray unit, and one direction A driven shaft that is urged to move in parallel with the driven shaft, a driven gear that is rotatably mounted on the driven shaft, and a biasing force that is applied to the driven shaft by being stretched between the roller shaft of the pullout roller and the driven shaft. A timing belt to which tension is applied, and a one-way clutch provided between the roller shaft of the pull-out roller and the gear train, Wherein comprising a driven gear meshed to lower its said drive gear of the paper feed tray unit,
Multi-stage paper feeder. 2. The multi-stage feeding according to claim 1, wherein the driven shaft is supported by a lever, the lever is rotatably provided, and a biasing member is biased to apply tension to the timing belt. Paper equipment. 3. A sheet feeding tray for storing sheets, a sheet conveying motor, and a gear train for transmitting the rotation of the motor.
A multi-staged paper feed tray unit having a paper feed roller and pull-out roller for transmitting the rotation of the motor through the gear train and a vertical passage is provided, and the sheets in the paper feed tray are fed out by the paper feed roller. In a multi-stage sheet feeding device that conveys the sheet through the pull-out roller and feeds it through the vertical passage of the sheet feeding tray unit in the upper stage, detecting means for detecting the sheet after passing through the pull-out roller, and detecting the sheet by the detecting means. A multi-stage sheet feeding device comprising: control means for stopping driving of the sheet conveying motor of the lower sheet feeding tray unit; and clutch means for interrupting rotation transmission from the pullout roller to the sheet conveying motor.