JPH0625242U - Paper separation device - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a sheet separating device that surely separates sheets stacked in a sheet feeding section into one sheet. [Structure] Bearing surface 1 defining one side of stacked sheets 3
Is formed with an inclined surface 20 at an angle such that a sheet of paper picked up by the pick roller 5 hits. A friction material 22 is adhered to the surface of the inclined surface 20, and the front edge portion of the sheet that has been double-fed by the pick roller 5 is squeezed by this portion to provide a separating action, and the pick roller 5 and the friction pad. 7 is guided to the nip portion 15 with which it abuts.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sheet separating apparatus that separates sheets stacked and stored in a sheet feeding section of a printer one by one and conveys the sheets to a printing section.

[0002]

[Prior art]

 Generally, a printer separates the sheets stacked and accommodated in a sheet feeding unit into one sheet, and performs processing such as printing on the separated sheets. As a device for separating the stacked sheets into one, conventionally, a device using a corner claw separation system and a friction pad system is known.

The corner claw separation type sheet feeding device presses the corners of the stacked sheets against the corner claws by the biasing means, and rotates the pick roller contacting the uppermost stacked sheet. As a result, the uppermost sheet is bent so that the uppermost sheet is removed from the corner claws and separated into one sheet. According to this corner claw separation method, separation of soft and relatively thin paper such as copy paper is suitable, but separation of hard paper and relatively thick paper such as postcards causes bending. Since it is difficult to form, it is difficult to separate one sheet.

On the other hand, the friction pad type sheet separating device has a frictional force generated between the pick roller and the sheet, a frictional force generated between the sheets and a frictional force generated between the sheet and the friction pad. Since the separation of the sheets is performed by utilizing the difference of 1), it is possible to relatively easily separate one sheet of the stacked sheets even if the sheets are hard in quality.

FIG. 5 is a diagram showing a configuration of a main part of a conventional paper separating device using a friction pad system. Sheets are stacked and accommodated on the bearing surface 1, and the stacked sheet 3 is biased in the direction indicated by the arrow, and the uppermost sheet P2 is pressed by the pick roller 5. The friction pad 7 is elastically biased to the pick roller 5 to form a nip portion 15. The sheets separated by the rotation of the pick roller 5 are arranged between the bearing surface 1 and the friction pad 7 through the gap G between the bearing surface 1 and the pick roller 5. The film 9 having a high elasticity (hereinafter, referred to as an elastic guide) is slid to be guided to the nip portion 15, passes through the nip portion 15 and is conveyed to a printing portion (not shown). In this figure, the paper P1 is drawn out by the pick roller 5 and passes through the nip portion 15.

As shown in FIG. 5, when the pick roller 5 rotates, one sheet of paper is peeled from the stacked sheets of paper and conveyed toward the nip portion 15, one sheet of paper is no problem. Separation is done. However, due to the influence of humidity, the condition of the paper, etc., the coefficient of friction between the papers may fluctuate, and the papers may be double-fed from the gap G (usually, the gap G is suitable for various papers. Or, it is about 0.2 mm to 0.8 mm so that it can be transported even if the paper is slightly bent). That is, in the state shown in the figure, when the coefficient of friction between the paper sheets P2 and P3 is higher than the coefficient of friction between the paper sheets P3 and P4, the paper sheets P2 and P3 are double-fed through the gap G. I will end up. In this case, the nip portion 15 separates one sheet of paper.

That is, the materials of the pick roller 5 and the friction pad 7 are as follows: the coefficient of friction between the pick roller and the paper is μ1, the coefficient of friction between the paper and the friction pad is μ2, and the friction between the paper and the paper. If the coefficient is μ3, it is set such that μ1> μ2> μ3. Then, based on this relationship, the sheets P2 and P3 that have been double-fed to the nip portion 15 are stopped at the portion of the friction pad 7 where the sheet P2 slides on the sheet P3 and prints as the pick roller 5 rotates. It is transported to the department.

[0008]

[Problems to be solved by the device]

 As shown in FIG. 5, the sheet P1 separated into one sheet is conveyed toward a printing unit (not shown). When the sheet P1 is conveyed to the print unit, the rotation of the pick roller 5 is stopped, and thereafter the sheet P1 is conveyed by the print unit. At this time, the pick roller 5 is rotated along with the conveyance operation of the paper P1.

As described above, the coefficient of friction between the sheets is not constant among all the sheets. For example, as shown in FIG. 6, when the coefficient of friction is low between the sheets P4 and P5, the sheet P2 is P3 and P4 are pulled out together with the rotation of the pick roller 5. Then, the papers P2, P3, P4 pulled out at the same time slide on the elastic guide 9 and are guided by the nip portion 15 to be in the state shown in FIG.

As shown in FIG. 7, when three sheets of paper are conveyed to the nip portion 15, when the pick roller 5 is driven again, it becomes difficult to separate one sheet of paper at this portion, and the sheet of paper becomes difficult to separate. Double feed or paper jam may occur. Alternatively, although not shown, even if two sheets of paper are guided to the nip portion 15 along with the rotation of the pick roller 5, there is a possibility that one sheet of paper may not be reliably separated at this nip portion. That is, when the friction coefficient between the sheets is high to some extent, the lower sheet does not stop at the friction pad 7 and passes through the nip portion together with the upper sheet.

As described above, at the front end of the bearing surface, the paper that is sent out along with the rotation of the pick roller 5 is sent to the nip portion as it is (two sheets for two sheets, three sheets for three sheets). The above-mentioned problems occur. The present invention has been made in order to solve the above problems, and an object thereof is to provide a sheet separating device that surely separates one sheet.

[0012]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, a sheet separating device of the present invention is provided with a bearing surface that defines one side surface of stacked sheets and a pick roller that abuts the stacked sheets and feeds the abutting sheets. And a friction pad elastically urged by the pick roller, the bearing surface is arranged at an angle such that the paper fed by the pick roller abuts, and a friction material is applied. It is characterized by the formation of an inclined surface.

[0013]

[Action]

 An inclined surface is formed on the bearing surface that defines one side of the stacked paper sheets, at an angle such that the paper rolled out by the pick roller abuts, and a friction material is applied to this inclined surface. When the sheets stacked by the pick roller are double-fed, the leading edge of the double-fed sheets abuts the friction material adhered to the inclined surface to receive the sheet separation action. The double-fed sheets are separated into one sheet here, or in a state where they are easily separated, and are conveyed to the nip portion where the pick roller and the friction pad contact each other.

[0014]

【Example】

 Hereinafter, the configuration and operation of the sheet separating apparatus according to the present invention will be described with reference to FIGS. 1 to 4. In the drawings described below, the same components as those in the conventional example described above are designated by the same reference numerals.

The friction pad 7 fixed to the pad base 7a is biased to the pick roller 5 provided on the drive shaft 5a by a biasing means (not shown). The paper sheet is conveyed to a printing unit (not shown) via a contact portion (nip portion) between the pick roller 5 and the friction pad 7. In this case, the materials of the pick roller 5 and the friction pad 7 are such that the friction coefficient between the pick roller and the paper is μ1, the friction coefficient between the paper and the friction pad is μ2, and the friction coefficient between the paper and the paper is μ2. When the friction coefficient is μ3, μ1> μ2> μ3.

On the bearing surface 1 on which the laminated paper is placed, a pair of inclined surface separating portions 25 are formed on the left and right of the pick roller 5. The inclined surface separating portion 25 includes an inclined surface 20 extending along the outer peripheral surface of the pick roller 5 when viewed from the side, and a friction material 22 such as cork or foam rubber is provided on the inclined surface 20. It is covered. Specifically, as shown in FIG. 2, the inclined surface 20 is arranged at an angle such that the sheet fed by the pick roller 5 abuts, and the friction material 22 and the pick roller 5 attached to the inclined surface 20. Between the upper part 20a and the lower part 20c, a substantially constant gap G is defined along the outer circumference of the pick roller 5. The gap G is about 0.2 mm to 0.8 mm so that various types of paper can be accommodated. Next, the operation of the sheet separating apparatus according to the present invention will be described with reference to FIGS.

The sheets 3 stacked on the support surface 1 are pressed against the pick roller 5 by an urging means (not shown) as shown by an arrow. After the pick roller 5 rotates, the uppermost sheet P1 passes through the nip portion 15 and is conveyed by a printing unit (not shown). At this time, the pick roller 5 is rotated by the conveyance operation of the sheet P1. In this case, if the coefficient of friction between the sheets of paper P3 and P4 is lower than the coefficient of friction between the sheets of paper P2 and P3, as shown in FIG. , P3 are sent out.

The leading edges of the two sheets fed at the same time are gradually squeezed by the angle of the inclined surface 20 and the friction material 22 to reach the lower portion 20c of the inclined surface 20, and are gradually separated one by one. Go. That is, as shown in FIGS. 2 and 3, the paper P3 gradually slides by the frictional force of the friction material 22, and the paper P2 slides on the paper P3.

Then, as shown in FIG. 4, when the pick roller 5 is driven again, only the sheet P2 is separated into one sheet and guided to the nip portion 15. Alternatively, although not shown, even if the double-fed sheets are not completely separated into one sheet by the slope separation section 25, in this case, the nip section 15 is guided in a state where the sheets are easily separated. It When the pick roller 5 double-feeds the sheets P3, P4, ... After the paper P2, the same action is exerted, and the inclined face separating portion 25 receives the separating action and is guided to the nip portion 15.

As described above, even if a plurality of sheets are sent to the gap G, the double-fed sheets are separated at the nip portion 15 because the slope separation portion 25 squeezes the leading edge thereof. A sheet of paper or a sheet that has been easily separated due to the separating action is guided. As a result, one sheet can be separated with high accuracy. Although the embodiment of the present invention has been described above, various changes can be made to the location of the slope separation portion 25 and the like.

[0021]

[Effect of device]

 As described above, according to the sheet separating device of the present invention, even if a plurality of sheets are sent out as the pick roller rotates, the slope formed on the supporting surface at the end of the supporting surface on which the sheets are stacked and placed. Since the separating portion exerts a separating action on the sheet, one sheet or a sheet that is easily separated comes to be conveyed to the nip portion where the pick roller and the friction pad contact each other. As a result, it becomes possible to reliably separate one sheet.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a sheet separating device according to the present invention.

FIG. 2 is a diagram showing a state in which the double-fed sheets are squeezed and separated by a slope separation section in the sheet separation apparatus shown in FIG.

FIG. 3 is a diagram showing a state in which a predetermined time has elapsed from the state shown in FIG.

FIG. 4 is a diagram showing a state in which a predetermined time has elapsed from the state shown in FIG.

FIG. 5 is a diagram showing a sheet separating unit in a conventional sheet separating apparatus.

FIG. 6 is a diagram showing a state in which sheets are double-fed by the sheet separating apparatus shown in FIG.

7 is a diagram showing a state in which a predetermined time has elapsed from the state shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bearing surface, 3 ... Laminated paper, 5 ... Pick roller, 7 ... Friction pad, 15 ... Nip part, 20 ... Inclined surface, 22
... Friction material, 25 ... Slope separation part.

Claims (1)

[Scope of utility model registration request] 1. A bearing surface that defines one side of stacked sheets, a pick roller that comes into contact with the stacked sheets and feeds out the sheets that are in contact, and a friction pad elastically biased by the pick rollers. In the paper separating apparatus having the above-mentioned, the supporting surface has an inclined surface which is arranged at an angle such that the paper fed out by the pick roller abuts and a friction material is adhered. .