JPH0733283A - Mass paper feeder - Google Patents

Abstract

(57) [Summary] [Purpose] As many sheets as possible can be stacked for each type of paper, and the user's paper replenishment work can be reduced as much as possible. [Structure] A table 41 is provided on a lift table 39 which is lifted and lowered by a lift mechanism and supported by a plurality of elastic members 40. Further, a detecting means 43 including a fixed contact piece 44 and a movable contact piece 45 is provided. Then, when replenishing the sheets with the replenishment sheets over the table 41 when replenishing the sheets, the movable contact piece 45 is pushed down by the table 41 lowered against the elastic members 40, and separated from the fixed contact piece 44. The lifting motor 48 of the lifting mechanism is prevented from operating.

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 paper recording device such as a facsimile machine or a printing machine, which records on paper by printing, transferring, copying, printing, or the like. More specifically, the present invention relates to such a sheet recording apparatus that supplies a large amount of sheets to the recording apparatus body.

[0002]

2. Description of the Related Art Conventionally, in a mass-feeding device used in a printer, for example, as shown in FIG. 7, a large amount of sheets 2 are placed on a table 1 and side fences are placed on both edges of the sheets 2. And apply the end fence 3 to the rear end 2a. Then, an elevating mechanism (not shown) is driven to raise the table 1, and the uppermost sheet is fed to the sheet feeding roller 4
The detection lever 5 rotatably supporting it is rotated about one of the separation roller shafts 6, and the sensor 7 detects that the detection lever 5 has rotated a predetermined angle, and the table 1 is raised. Then, the uppermost sheet of the stacked sheets 2 is set as the sheet feeding height as shown in FIG.

As a result, the paper feed roller 4 is rotated to feed the stacked sheets 2 sequentially from above, and as the loaded sheets 2 decrease, the table 1 is raised by the elevating mechanism and the fed sheets 2 are separated by the separation roller pair 8. It was separated by 1 at 8 and sent out.

By the way, in this kind of large-volume sheet feeding device, it is not allowed that the designing allowable strength is exceeded due to overloading of the sheets 2, the operation safety is impaired, and the reliability is impaired. . Therefore, conventionally, for example, the maximum loading height is displayed on a side fence or the like, and the loading of the paper 2 exceeding the maximum loading height is prohibited.

[0005]

However, even if the stacking height is the same, if the paper size is different, the weight of the stacked paper 2 as a whole will be different, and even if the stacking height is the same and the paper size is the same, the paper size is the same. If the weight per unit volume is different, the weight of the whole stacked sheets 2 is naturally different. For this reason, conventionally, the maximum stacking height has been determined based on the largest paper size and the heaviest paper weight.

Therefore, in the past, although there is still room for some types of paper, the stacking height is limited to the maximum stacking height display, which results in a heavy burden on the user for paper supply. It was

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to make it possible to stack as many sheets as possible according to the type of sheets, and to reduce the user's time and effort for paper supply as much as possible.

[0008]

Therefore, the present invention provides
For example, as shown in the illustrated embodiment below, a table 41
A large amount of paper 14 is placed on top of the stacked paper 1
In the mass paper feeder 12 that feeds the stacked sheets 14 one by one from the top while raising the table 41 with the decrease of 4, the lifting table 39 is raised and lowered by the raising and lowering mechanism 29.
The table 41 is supported on the elastic member 40.
And a detection means 43 for detecting that the table 41 is sunk by the weight of the stacked sheets 14 against the elastic members 40 .. It is characterized by

A circuit structure for stopping the operation of the elevating mechanism 29 when detected by the detecting means 43 is provided.

[0010]

As a result, when the paper 14 is replenished, if the weight of the stacked paper 14 placed on the table 41 exceeds a certain limit, it is detected by the detection means 43, and the operation of the elevating mechanism 29 is stopped. Or display an overload warning.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 5 shows a laser printer using the large-volume sheet feeding device according to the present invention. Reference numeral 10 in the drawing is a laser printer main body. Laser printer body 1
The paper feeding cassette 11 is detachably attached to the paper feeder 0, and the mass paper feeding device 12 according to the present invention is assembled.

When recording on a large amount of paper,
The paper feed roller 13 in the large-volume paper feed device 12 is rotated to sequentially feed the stacked paper 14 from above, and the separation roller pair 15 and 15
Then, the sheets are separated one by one and placed in the sheet conveying path 16, and are abutted against the pair of registration rollers 17 and 17 through the sheet conveying path 16 and fed onto the photoconductor 18 at a timing. On the other hand, the drum-shaped photoconductor 18 rotates counterclockwise in the drawing, and an image is formed on the surface thereof by the charger 19, the laser writer 20, and the developing device 21. Then, the image on the photoconductor 18 is transferred by the transfer device 22 onto the sheet 14 sent onto the photoconductor 18. The sheet 14 after the image transfer is fixed by the fixing device 23.
Then, after the transferred image is fixed there, it is discharged by the discharge roller 24 and stacked on the discharge tray 25. On the other hand, the photoconductor 18 cleans the residual toner after the image transfer by the cleaning device 26.
Then, an image is formed on the surface again by the charging device 19, the laser writing device 20, and the developing device 21. Then, by repeating this, the sheets are similarly transferred to the sheet 14 one after another, and the discharge tray 2
Stack 5 on top.

By the way, the mass paper feeder 1 according to the present invention.
2, the inner case 28 as shown in FIG. 4 is provided in the box-shaped outer case 27 shown in FIG. 5, and the elevating mechanism 29 is attached to the inner case 28. The lifting mechanism 29 is the motor 3
0 is driven, the shaft 33 is rotated through the meshing of the worm 31 and the worm gear 32, and the wires 35 are guided by a plurality of pulleys 34 on both sides of the inner case 28. By driving the wire 37 by guiding the stays 38, 38 along the pair of vertically elongated guide holes 28a, 28b of the inner case 28.
Move up and down. On the stays 38, 38, as shown in FIG. 3, a slightly thick plate-shaped lifting table 39 is horizontally mounted.

A slightly thin, plate-like table 41 is horizontally provided on the lift table 39 through a plurality of coil spring-like elastic members 40 .... As shown in FIG. 2, the table 41 has an escape hole 41a that is long in the sheet feeding direction (the direction indicated by the arrow in the figure).
To provide. Then, the end fence 42 is provided upright through the escape hole 41a, and the end fence 42 is movable in the sheet feeding direction by a known means similar to the conventional one.

Further, between the lifting platform 39 and the table 41,
The detection means 43 is attached to the lifting table 39. As can be seen from FIG. 1, the detecting means 43 comprises a fixed contact piece 44 and a movable contact piece 45, the fixed contact piece 44 is connected to a power source 47 via a switch 46, and the movable contact piece 45 is a motor 48 for raising and lowering.
The circuit configuration is such that it is connected to the power supply 47 via the.

Now, when replenishing the paper 14 to the mass paper feeder 12, the elevating mechanism 29 is operated to lower the elevating table 39 to the lowest position, insert it from the outer case 27, and place it on the table 41. Then, the sheets 14 are stacked. Then, the weight of the stacked sheets 14 resists the elastic members 40 ...
1 sinks. However, when the sheets 14 are replenished within the stackable range, the operation of the elevating mechanism 29 is ensured without the table 41 contacting the movable contact piece 45. Therefore, a side fence (not shown) is applied to the side edge of the stacked sheets 14 and the elevating mechanism 29 is operated to set the uppermost sheet 14 to the sheet feeding height as shown in FIG.
3 is rotated and separated by the separation rollers 15 and 15, and the stacked sheets 14 are sequentially sent out from above.

However, when the paper 14 is replenished in excess of the weight that can be loaded on the table 41, the table 41 contacts the movable contact piece 45 and separates it from the fixed contact piece 44.
It is detected that the distance between the table 41 and the lifting table 39 is below a certain value. As a result, if the mass paper feeder 12 is operated in this state, the safety and reliability of the operation may be impaired. Therefore, even if the switch 46 is turned on, the motor 48 is not driven and the elevating mechanism 29 is not operated. To do so. Further, if necessary, an overload may be displayed at an appropriate place on the large-volume paper feeding device 12 or the laser printer main body 10 to warn the user.

In the illustrated embodiment described above, the detection means 43 is composed of the fixed contact piece 44 and the movable contact piece 45. However, the detection means 43 is not limited to such a mechanical one, and an optical sensor using an optical sensor is used. It may be a magnetic one using a magnetic sensor, or a physical one using a piezoelectric element.

Further, although the elastic member has a coil spring shape, it may naturally have a leaf spring shape or the like. It is only necessary that the space between the table 41 and the lift table 39 can be displaced according to the weight of the stacked sheets 14.

[0020]

Therefore, according to the present invention, the safety and certainty of the operation of the large-volume sheet feeding device is accurately ensured according to the type of paper, so that as many sheets as possible for each type of paper are The sheets can be stacked, and the user's time and effort for paper supply can be reduced as much as possible. Further, by providing a circuit configuration for stopping the operation of the elevating mechanism when detected by the detecting means, the elevating mechanism is prevented from operating when overloaded, and safety and certainty of operation are secured.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a main part of a mass-feeding device according to the present invention.

FIG. 2 is a perspective view showing the lifting table, table, and end fence.

FIG. 3 is an overall schematic configuration diagram of the mass paper feeder.

FIG. 4 is a perspective view showing an elevating mechanism attached to the inner frame.

FIG. 5 is an overall schematic configuration diagram of a laser printer using the mass-feeding device.

FIG. 6 is an explanatory diagram of a paper feeding state in a conventional bulk paper feeder.

FIG. 7 is a schematic configuration explanatory diagram of a paper supply state.

[Explanation of symbols]

 12 Mass Paper Feeding Device 14 Paper 29 Elevating Mechanism 39 Elevating Table 40 Elastic Member 41 Table 43 Detecting Means

Claims (2)

[Claims] 1. A large-scale sheet feeding device for placing a large number of sheets on a table and stacking a large number of sheets and feeding the sheets one by one from the top while raising the table as the number of sheets stacked decreases. The table is provided while being supported by an elastic member via an elastic member that is lifted by a mechanism.
A mass-feeding device comprising: a detection unit that detects that the table is sunk by the weight of the stacked sheets against the elastic member and the distance between the table and the elevating table is below a certain value. 2. The mass paper feeder according to claim 1, further comprising a circuit configuration for stopping the operation of the elevating mechanism when detected by the detecting means.