JPS63218450A - Sheet feed device - Google Patents

Abstract

PURPOSE:To make it possible to smoothly feed paper by providing a guide member for making a sheet into press contact with a conveying member, a sheet detecting means provided downstream of the conveying member in the paper feed direction, and means for decreasing the acting force of the guide member upon the sheet after the sheet detecting means detects the sheet. CONSTITUTION:A certain number of paper sheets P are fed into between a conveying roller 2 and a separating roller 3 from a take-up roller 1, and the certain number of paper sheets P is fed through a guide member 7 from the conveying roller 2. When the paper sheets P which go away from the conveying roller 2 are detected by a sheet detecting means 6, a solenoid 9 is energized so that the guide ember is separated from the conveying roller 2. Then, only one of the paper sheets P held between the conveying roller 2 and the separating roller 3, which is nearest to the conveying roller 2, is conveyed while the remainder is returned in the direction reverse to the conveying direction. Further, the only one separated paper sheet P is fed into a reading section at a constant speed by means of upper and lower conveying rollers 4, 5. When a paper feed instruction is issued again, the take-up roller 1 is rotated so that the similar steps are repeated.

Description

[Detailed Description of the Invention] [Industrial Application Fields] The present invention is applicable to an electronic copying machine, facsimile machine, image reading device, etc., in which stacked sheet originals are automatically scanned one by one by the original illumination unit and the reading unit. The present invention relates to an automatic sheet document feeding device for feeding copy paper or printing paper in an electronic copying machine or printing machine.

[Prior Art] Conventionally, as this type of single-sheet separation and feeding apparatus, there is a friction pad system in which an upper roller 2 rotating in the sheet conveying direction and a separation pad 14 are in contact with each other as shown in FIG. It is a friction roller type in which an upper roller 2 that rotates in the conveying direction and a separation roller 3 that stops or reverses are in contact with each other, and consists of a pair of upper and lower endless belts 15 and 16 that are in contact with each other as shown in FIG. This is a friction belt type in which the belt 16 is rotated in the conveying direction and the other belt 16 is stopped or rotated in the opposite direction.
From a plurality of upper and lower endless belts 15 and 16 in which the lower belt overlaps, one belt 15 is rotated in the sheet conveyance direction and the other belt 16 is stopped or rotated in the opposite direction, such as a belt paper waist separation method. There is.

[Problems to be Solved by the Invention] However, in all of the above conventional examples, the separating member stops or rotates in the opposite direction before the paper is separated and comes out of the conveying member. However, the tip of the paper may break or tear when it hits the separation member (Fig. 8) (Fig. 9), causing jams, etc. This was especially noticeable with damaged paper, and was the biggest weakness of the friction separation method.

[Means for Solving the Problems (and Effects)] According to the present invention, there is provided a guide member that brings the sheet into pressure contact with the conveying member, a sheet detecting means provided on the downstream side of the conveying member in the sheet feeding direction; By providing a means for reducing the force exerted by the guide member on the sheet after the sheet detecting means detects the sheet, the ease of paper entry is greatly improved and the paper can be fed smoothly.

[Example] Figures 1 and 2 show examples of the present invention, where 1 is a calling roller for feeding paper into a separating section, 2 is an upper roller which is a conveying member for feeding paper, and 3 is a paper separating part. 4.5 is a lower conveyance roller for feeding the sheets of paper sent in one sheet to the reading unit at a constant speed; 6 is the paper that comes out from the conveyance roller; 7 is a guide member for feeding paper, 8 is a rotating shaft of the guide member, 9 is a solenoid for separating the guide member from the conveyance roller, IO is a plunger thereof, 11 is a link, 12 is a stopper, 1
3 is a spring for bringing the guide member into contact with the conveyance roller;
A controller 18 issues a drive signal to the plow solenoid 9 in response to a paper detection signal from the sensor 7.

In the above configuration, a certain number of sheets of paper are sent from the pick-up roller 1 between the transport roller 2 and the separation roller 3, a certain number of sheets are sent from the transport roller by the guide member 7, and when the paper comes out of the transport roller It is sensed by the paper detection member 6.

When paper is detected, the solenoid 9 or the guide member 7 moves away from the conveyance roller.Then, among the paper between the conveyance roller and the separation roller, only the paper closest to the conveyance roller is conveyed, and the rest are moved in the conveyance direction. is returned in the opposite direction, and the separated paper is sent to a reading section (not shown) at a constant speed by 4.5 upper and lower transport rollers. When a paper feed command is issued again, the first calling roller rotates and the same process is repeated.

[Other Examples] In the example shown in FIG. 10, the guide member is formed by forming a layer 20 of non-woven fabric on the guide surface side of a base material 19 made of a sheet metal, and has the same effect as the previous example.

Various other modifications can be considered for the guide member, for example, as shown in FIG.
1, as shown in FIG. 12, a wire rod 17, as shown in FIG. 13, as shown in FIG.

Further, the conveying member or the separating member may be one that rotates together with a belt.

Furthermore, as shown in FIG. 14, the guide member 7 may be arranged in a groove 3B provided in the separation roller 3.

[Effects of the Invention] As explained above, by providing a guide member between the conveyance roller and the separation member, a certain number of sheets of paper are sent out by the conveyance roller once, and this is detected by a sensor, and the guide member is released and only the topmost paper is sent out. Papers smaller than this are separated using a separation member to eliminate paper misfeeding. Even if the paper has a damaged tip, it will begin to separate after a few feeds and can be fed easily.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the present invention. FIG. 2 is a diagram showing the positions of the conveyance roller, separation roller, and guide member from the side. FIGS. 3 to 9 are diagrams showing conventional sheet feeding devices. FIGS. 1O to 14 are diagrams showing other embodiments of the present invention. 1 is the calling roller 2 is the conveyance roller 3 is the separation roller 4 is the upper conveyance roller 5 is the lower conveyance roller 6 is the paper sensor 7 is the guide member 8 is the guide member shaft 9 is the solenoid IO is the plunger 11 is the link 12 is the stopper 13 The spring 14 is the friction butt 15 is the conveyor belt 16 is the separation belt mud 11η.

Claims (1)

[Scope of Claims] A sheet feeding device that separates and feeds sheets using a conveying member that rotates in the sheet feeding direction and a separation member that is close to or in contact with the conveying member and rotates in the opposite direction to the sheet conveying direction. , a guide member that presses the sheet against the conveying member; a sheet detecting means provided downstream of the conveying member in the sheet feeding direction; and after the sheet detecting means detects the sheet, the force acting on the sheet of the guide member is detected. A sheet feeding device characterized in that it has a means for reducing the number of sheets.