JPH0423747A - Paper feeding device - Google Patents

Abstract

PURPOSE:To improve reliability of a device in a paper feeding device of sheets such as high density tracing paper, OHP or the like by blowing the air against an end surface of piled sheets with an air blowing means to float it, and co-operating with a presser member. CONSTITUTION:A compact blower 20 using a motor with rating of 0.3 A at direct 24 V is fitted to a part of a side surface guide plate 8 of a paper feeding device 1, and a nozzle 22 having an air blow port 21 for forming air flow to a part close to a feeding part of the stacked paper is connected to the blower 20. Length of the air blow port 21 is set at the full of wideness of the paper facing to the air blow port, or a part thereof is also well, and shape is not specified. The air blow port 21 is desirably set so that a lower end A of the opening is positioned under the top surface B of the piled paper and that an upper end of the opening is positioned upper than the top surface B of the piled paper. A sheet presser member 23 made of SUS material is provided in the side surface guide plate 8 so as to be placed on a side end of the paper with deadweight thereof. About air blow timing of the air blower 20, either of continuous timing or intermittent timing is good for obtaining a good result.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is applicable to paper, high-density tracing paper, OHP
The present invention is intended to provide a paper feeding device for equal sheets, and more specifically, to a device that can reliably feed sheets one by one from stacked sheets when feeding these sheets.

(Prior Art) Conventionally, in copiers, printers, etc., cut sheets that can be continuously fed have generally been limited to high-quality paper, tracing paper for copiers specified by copier manufacturers, and the like. Since such paper has a low surface smoothness, when sheets are fed out one by one from a stack of sheets, it is rare for the sheets to attract each other and cause double feeding. Moreover, even if double feeding was performed, the sheets could be fed out one by one relatively well using a separating roller, a separating pad, or a separating claw.

However, recently, market demands have become more diverse, including color, and there is an increasing demand for copying or printing on papers with smooth surfaces, such as highly transparent tracing paper, glossy art paper, and coated paper. It's coming.

However, general commercially available tracing paper and OH
Sheets with highly smooth surfaces, such as P film, had extremely low paper feeding reliability. The reason for this is that it is difficult for an air layer to form between the sheets, and even if the operator separates them and sets them on the paper feed tray, they will return to their original state over time and the effect of separating them will disappear. there were.

As a result, the conventional sheet feeding device cannot obtain sufficient conveying force to feed the sheet, resulting in misfeeds. Furthermore, even if the paper could be fed out, there were many cases where multiple sheets of paper were fed out in close contact with each other, resulting in double feeding.

As a countermeasure for these, for example, Utility Model Application No. 59-195128
The paper feeding method described in the publication proposes blowing air between the sheets of paper from the rear of the paper feed.
Japanese Utility Model Application Publication No. 61-21735 proposes a method for improving this by blowing air from the side of paper feeding. A method of blowing air between the sheets from in front of the sheets as they are fed out has been proposed in Japanese Patent Laid-Open Nos. 62-249835 and 60-44435.

However, even if air is blown, there is a problem in that the air is not blown to all of the stacked sheets, and double feeding still occurs. Similarly, OHPs with high surface smoothness also have similar problems.

Additionally, conventional air supply means have the disadvantage of being large and noisy.

(Problems to be Solved by the Invention) The present invention has been made in view of these circumstances, and uses a small air blowing means without being subject to restrictions such as the thickness of the sheet and the surface smoothness of the sheet. The purpose is to reliably feed one sheet at a time.

(Means for Solving the Problems) The present invention blows air into the end faces of stacked sheets using an air blowing means to levitate the sheets, and in cooperation with a sheet pressing member, air penetrates between the sheets. , definitely 1! This is a paper feeding device that can feed paper in increments of 'i'.

Here, the end surface of the sheet may be in any of the front, rear, and lateral directions with respect to the sheet feeding direction, and the sheet refers to the copying machine,
These are sheets of plain paper, art paper, high-quality paper, tracing paper OHP, etc. used in pre-sitters, etc.

The blown air flow may be constant, but
It is preferable to intermittent the blowing of air, change the flow rate or pressure, or change the direction because this further enhances the cleaning effect.

The sheet holding member of the present invention assists the air blown into the end faces of the stacked sheets by the air blowing means to penetrate between the sheets from one end where it is blown to the opposite end. It is a sheet that can be stacked freely and placed in contact with the top surface of the sheet or with a slight gap, and whether it is roll-shaped, brush-shaped, or plate-shaped. There may be.

(Function) In a sheet feeding device having an air blowing means, the sheet is levitated by the air liquid blown into the end surface of the sheet, and air enters between the sheets, which weakens the bonding force between the sheets and will be dealt with.

Since the sheet pressing member is arranged on the stacked sheets, the air that enters the sheet interface from one end can penetrate between the sheets to the other opposite end, and the sheets can be separated more reliably. . The effect of this sheet pressing member will be explained using FIGS. 7(A), (B), and FIG. 8.

If there is no sheet holding member, as shown in Figure 7 (A), more sheets than necessary may float up, making it impossible to handle the few sheets at the top. When the holding portion and the material are provided, as shown in FIG. 7(B), the floating of the sheet is prevented from becoming too large, and air is reliably blown between the sheets.

In addition, if there is no sheet holding member, as shown in Figure 8, for small size sheets such as A4 size, air will escape and be discharged toward the open rear end side as shown in 40. , the close contact area 41 between the sheets is left behind, which tends to cause misfeeds, double feeding, skew, etc., and even if the floor is made somewhat larger and the wind strength is increased,
Nagana is not improved. However, when a sheet holding member is placed, the airflow can easily penetrate through the paper interface from one end to the opposite end, and even wind from a small blower can eliminate the part of the sheet that is in close contact with the paper. Become.

(Example 1) FIG. 1 shows an apparatus for explaining one example of the present invention.
(A) is a side view of the air blower of this embodiment with the floor omitted, (B) is a rear view with the sheet pressing member omitted, and Fig. 2 is a perspective view of the protruding roll housing. . In the figure, reference numeral 1 denotes a main body of a paper feeder, and the sheets 4 stacked in this paper feeder are held in a paper feed tray 10, and the paper feed tray 101. According to the number of sheets fed, the ejector roll housing 3 supporting the ejector roll 2 is moved upward in small increments so as to come into contact with the top of the paper 4 under its own weight.

The protruding roll housing 3 is rotatable around the paper feed roll shaft 61, and as the tray 10 rises, the uppermost surface of the paper 4 comes into contact with the roll 2, and is pushed upward slightly. A position detecting means 5 as shown in FIG. 2 is arranged so as to stop at a certain position. As shown in FIG. 2, the position detection sensor 5 for operating the paper feed tray 1 includes a protrusion 5o, which is a detection shielding member provided on a part of the protruding roll housing 3, and a protrusion 5o provided thereon. A photo sensor 5 correspondingly arranged on the main body of the paper feeder
It consists of 1. On the downstream side of the ejection roll 2, a paper feed roll 6 and a separation roll 7 are provided which are in contact with each other with appropriate pressure in order to prevent the sheets 40 fed by the ejection roll 2 from being fed in duplicate. The paper feeding device 1 is provided with a side guide plate 8 that defines the position of one side of the paper, and a movable stop plate 9 that regulates the other end which changes depending on the paper size. A small floor 20 is attached to a part of the side guide plate 8, and an air flow is blown onto it. Small floor-2
0 used a motor rated at 24 V DC and 0.3 A.

A nozzle 22 with an air outlet 21 is connected to the small floor 20 in order to create an air flow to the part of the stack near the delivery. The length of the air outlet 21 may extend over the entire width of the facing sheet, or may extend over a portion thereof, and the shape thereof is not particularly limited. As shown in FIG. 3, the position of the air outlet 21 is such that the lower end A of the opening is below the upper surface B of stacking paper, and the upper end C of the opening is lower than the upper surface B of stacking sheets.
The preferred condition for achieving the objective was to set it above the . Small blower 20 that blows air
The air blowing timing is either continuous or intermittently. The air blowing and supply timing can be set arbitrarily, but for example, in a 40CPM copying machine, if the ON time and ○FF time are set to 4 seconds to 1 second and 2 seconds to 1 second, and within 1 feed time. Good results are also obtained when 0N10FF is used (for example, ON for 1 second, 0FF for 0.5 seconds). Also the fourth
As shown in Figure (A), a sheet pressing member 23 is provided on the side guide plate. This sheet pressing member 23, shown in FIG. 4(B), is made of SUS material and is adapted to rest on the side edge of the sheet by its own weight.

By doing so, it was possible to reliably feed highly smooth sheets such as tracing paper, art paper, and OHP sheets.

(Example 2) Instead of the sheet pressing member shown in FIG. 5(A), the sheet pressing member shown in FIG.
Table 1 shows the results when art paper was fed using a paper feeding device that was the same as in Example 1 except that a flange-shaped sheet pressing member 231 was provided near the center of the rear end of the sheet as shown in ). . In this case, even if the supporting material of the brush-shaped sheet pressing member is fixed to the side guide plate, the fluctuations in the paper surface due to the vertical movement variations of the elm tray can be absorbed by the deflection of the bristles of the brush.

However, since the sheet pressing member is for preventing the sheet from floating, the pressing force against the sheet may be slight or zero, and there may be a slight gap.

In addition, when air is blown from a direction transverse to the sheet feeding direction as in this case, arranging the sheet pressing member near the center of the rear end is effective in preventing the occurrence of skew.

Table 1 Paper feeding results (Examples 3 to 4) In place of the sheet pressing member in FIG. 5(A),
), a plastic roll with a diameter of 10 mm was arranged as a sheet pressing member 232 so that it could vibrate under its own weight and come into contact with the paper. In this case as well, the paper feeding performance had a pleasant odor.

Furthermore, if a short vibrating roll as shown in FIG. 6) is arranged as the sheet pressing member 233 instead of the sheet pressing member shown in FIG. demonstrated performance.

The paper feeding system of the present invention has been described using a paper feeding roll and a separation roll, and is fed while being sorted, but sufficient effects can also be obtained with a paper feeding system having corner claws 31 as shown in FIG. It is.

(Effects of the Invention) As described above, according to the present invention, a stack of sheets such as plain paper, tracing paper, OHP sheet, coated paper, etc. It is now possible to reliably feed paper one at a time, preventing double feeds and misfeeds, and greatly improving the reliability of the device.

In addition, since all you need to do is attach a small blower to the paper feed cassette or its vicinity and provide a simple sheet holding member, it does not take up space and does not require a large amount of electricity, so it can be used in small copying machines, printers, etc. Applicable. Furthermore, even when there are several paper feed trays, each tray can be installed independently, making it easy to control the air blowing conditions, etc.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a paper feeding device for explaining the present invention. FIG. 2 is a configuration diagram of the protruding roll section. FIG. 3 is a layout diagram of the positional relationship with the air outlet. FIG. 4 is a layout diagram of the sheet pressing member. FIG. 5 is a configuration diagram showing another embodiment. Figure 6 shows
FIG. 3 is a perspective view of a paper feed tray using corner claws. FIG. 7 is a diagram showing the effects of the case (A) without the sheet pressing member and the case <8) with the sheet pressing member of the present invention. FIG. 8 is a diagram showing airflow in a conventional example. 1... Paper feeder main body, 2... Bump ratio roll, 3...
・Protruding roll housing, 4... Paper, 6... Paper feed roll, 7... Separation roll, 10... Paper feed tray, 20... Small blower, 21... Air outlet, 22...
... Nozzle, 23... Sheet holding member Figure 3 (A) Figure 4 Almost Figure 5 Procedural amendment (method) % formula % Fuji Xerox Co., Ltd. Intellectual Property Department Tel: 0462 (38) 3111 Name ( 9347) Patent attorney 1st grade) Fuji separation Same place
5zu-゛Name (8883) Patent attorney Early notice Date of amendment order ゛-1-August 13, 1990 (all date of delivery August 28, 1990) Subject of amendment Contents of drawing amendment 1990 All drawings submitted on the 18th of the 5th sword will be corrected as attached.

Claims (1)

[Claims] (1) a paper feeding means for feeding out the stacked sheets; an air blowing means for blowing air into the end surfaces of the sheets;
A sheet feeding device comprising a sheet pressing member for controlling sheet flotation.