JPH0532342U - Paper feeder - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent double feeding of recording paper more reliably. [Structure] A bottomed cylindrical portion 1 that contacts the surface of the uppermost recording paper 2 in the vicinity of the separation claw 17 on the middle plate 18 of the printer case 1.
9 is formed. For this reason, the force required to curl the recording paper 2 increases, and only the uppermost recording paper 2 that is given the largest conveying force by the picking roller 12 and produces the largest curling force is curled, and the second and subsequent sheets are curled. The recording paper 2 of No. 1 is given a much smaller transporting force than the recording paper 2 of the uppermost level, whereby only the recording paper 2 of the uppermost level is reliably separated and the double feeding of the recording papers 2 is more reliably performed. To be prevented.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sheet feeding device used in a printer or the like.

[0002]

[Prior Art]

 In printers and the like, recording paper is fed by a paper feeding device. This type of paper feeding device is provided with a paper feeding cassette for accommodating recording paper, and the recording paper is taken out from the paper feeding cassette and fed. A picking roller that is rotated while being pressed against the surface of the uppermost recording paper in the paper feeding cassette is provided above the paper feeding cassette, and this picking roller provides a conveying force to the recording paper in the paper feeding cassette. The recording paper is attached and taken out from the paper cassette. In addition, the paper feed cassette is provided with separation claws on both sides of the front end that engage with the front edge corners of the recording paper, and the separation claws allow the topmost recording when the recording paper is taken out from the paper feed cassette. The paper curls to prevent double feeding of recording paper. That is, when the picking roller applies a conveying force to the uppermost recording sheet when the recording sheet is taken out from the paper cassette, the corner front edge of the uppermost recording sheet is separated by the conveying force. The uppermost recording paper curls when pressed by the nails and receives the reaction force, and the curl separates the uppermost recording paper to prevent double feeding of the recording paper.

[0003]

[Problems to be solved by the device]

 However, in the above-described conventional paper feeding device, some picking force is applied to the second and subsequent recording papers by the picking roller, and the second and subsequent printing papers receive the highest feeding force due to the carrying force. There was a case where the recording paper was pressed by the separating claw and curled, and a plurality of recording paper sheets were taken out from the paper feed cassette.

An object of the present invention is to provide a paper feeding device that can more reliably prevent double feeding of recording paper.

[0005]

[Means for Solving the Problems]

 In the paper feeding device according to the present invention, a paper feeding cassette for accommodating the recording paper, and a picking roller for taking out the recording paper from the paper feeding cassette by rotating while being pressed against the surface of the uppermost recording paper in the paper feeding cassette. , Separation pawls that are provided on both sides of the front end of the paper feed cassette so as to engage with the front end corners of the recording paper, and curl the recording paper when taking it out of the paper feed cassette; And a limiting member that is provided so as to face the surface of the uppermost recording sheet in the cassette and limits the curl area of the recording sheet when the recording sheet is taken out from the paper feeding cassette. There is.

[0006]

[Action]

 According to the paper feeding device of the present invention, the picking roller is rotated while being pressed against the surface of the uppermost recording paper in the paper feeding cassette, and the recording paper is taken out from the paper feeding cassette. At the time of this take-out, the recording paper is curled by the separating claw, and at the time of this curling, the curling area of the recording paper is limited by the limiting member.

Therefore, the force required to curl the recording paper by the restricting member increases, and only the uppermost recording paper that gives the largest curling force by the picking roller gives the largest carrying force, so that the two sheets are curled. The recording paper after the first recording paper is given a much smaller conveying force than the recording paper at the top, and the ejection of the second and subsequent recording papers is suppressed.

[0008]

【Example】

 An embodiment of a paper feeding device according to the present invention will be described below with reference to the drawings. This embodiment is applied to a printer. In this printer, as shown in FIGS. 1 and 2, a paper feed cassette 3 for accommodating recording paper 2 is mounted inside a rectangular box-shaped printer case 1. The recording paper 2 can be fed from the inside of the paper feed cassette 3 to the printing mechanism unit 4 for printing.

The printing mechanism section 4 is provided with a platen 5 and a print head 6 facing the platen 5 above the platen 5, and the recording paper 2 is fed between the print head 6 and the platen 5. It is designed to be printed. The platen 5 extends in a direction (a direction perpendicular to the paper surface of FIG. 2) that is directly orthogonal to the paper feeding direction. The print head 6 is integrally formed at one end with a U-shaped bearing portion 6a slidably fitted with the guide shaft 7, and at the other end with a slider 6b slidably fitted with the guide shaft 8. Is mounted and guided by the guide shafts 7 and 8 to be driven in parallel with the platen 5.

A paper feed roller 9 is provided on the upstream side and a paper discharge roller 10 is provided on the downstream side in the vicinity of the print mechanism unit 4, and the recording paper 2 is printed by the paper feed roller 9 on the print mechanism unit 4. 4, the recording paper 2 is discharged by the paper discharge roller 10 after printing. A paper discharge port 11 is provided downstream of the paper discharge roller 10, and the recording paper 2 is discharged to the outside of the printer case 1 through the paper discharge port 11. A picking roller 12 is provided upstream of the paper feed roller 9, and the recording paper 2 is taken out from the paper feed cassette 3 by the picking roller 12. The picking roller 12 is rotated above the paper feed cassette 3 while being pressed against the surface of the uppermost recording paper 2 in the paper feed cassette 3.

The paper feeding cassette 3 is provided with a rectangular box-shaped case 14, and the recording paper 2 is accommodated in the case 14. Inside the case 14, side plates 15 are erected on both sides, and the recording paper 2 is accommodated between the side plates 15. A hopper plate 16 is provided between the side plates 15, and the recording paper 2 is placed on the hopper plate 16. The hopper plate 16 is pivotally supported on the bottom plate of the case 14 so as to be vertically swingable, and is biased upward by a biasing means (not shown). Separation claws 17 are attached to the front ends of both side plates 15, and the front end corners of the recording paper 2 are engaged with the separation claws 17. A front wall 17a facing the front edge of the recording paper 2 is formed on the separation claw 17, and the front wall 17a curls the recording paper 2 when it is taken out from the paper feed cassette 3. That is, when the recording paper 2 is taken out from the paper feed cassette 3, the front edge of the recording paper 2 is pressed against the front wall 17a of the separation claw 17, and the recording paper 2 is curled by receiving this reaction force. ing.

An intermediate plate 18 of the printer case 1 is provided above the paper feed cassette 3, and the uppermost plate near the separation claw 17 is provided on both sides of the front end of the intermediate plate 18 as shown in FIG. A bottomed tubular portion 19 is formed as a limiting member that comes into contact with the surface of the recording paper 2. The bottomed cylindrical portion 19 limits the curling area of the recording paper 2 when the recording paper 2 is taken out of the paper feed cassette 3. That is, the bottomed cylindrical portion 19 abuts the surface of the uppermost recording paper 2 inside the curled region (the range indicated by the alternate long and short dash line in FIG. 1) of the recording paper 2 in the free state. The curl area of the recording paper 2 is restricted by 19 to the range shown by the chain double-dashed line in FIG. The bottomed tubular portion 19 is configured to slip easily with respect to the recording paper 2 so as not to hinder the conveyance of the recording paper 2, and may be subjected to a friction reducing treatment such as Teflon coating if necessary. is there.

Next, the operation will be described. At the time of paper feeding, the picking roller 12 takes out the recording paper 2 from the paper feeding cassette 3, and thereafter, the paper feeding roller 9 feeds the recording paper 2 between the print head 6 and the platen 5 for printing. After printing, the recording paper 2 is ejected to the outside of the printer case 1 through the paper ejection port 11 by the paper ejection roller 10.

Here, when the recording paper 2 is taken out of the paper feed cassette 3, the recording paper 2 is curled by the separating claw 17, and at the time of this curling, the curled area of the recording paper 2 is curled by the bottomed cylindrical portion 19. Is limited.

Therefore, the force required to curl the recording paper 2 by the bottomed tubular portion 19 increases, and the picking roller 12 imparts the largest carrying force to produce the largest curling force. Only the paper 2 is curled, and the second and subsequent recording papers 2 are given a much smaller transporting force than the uppermost recording paper 2. This ensures that only the uppermost recording paper 2 is separated. As a result, double feeding of the recording paper 2 is prevented more reliably. The picking roller 12 is formed of a high-friction member to increase the friction coefficient between the picking roller 12 and the recording paper 2 so that the conveyance force of the uppermost recording paper 2 is the same as that of the second and subsequent recording papers 2. If the curl force of the second and subsequent recording papers 2 is made significantly smaller than the curl force of the uppermost recording paper 2 if it is set to be significantly larger than the conveying force, the second and subsequent recording papers 2 Curl can be more reliably suppressed, and double feeding of the recording paper 2 can be prevented more reliably.

Further, since the curled area of the recording paper 2 is limited by the bottomed tubular portion 19, the curl height of the recording paper 2 is also lowered, and the space for curling the recording paper 2 is reduced and the printer It can contribute to miniaturization.

Further, since the force required to curl the recording paper 2 increases, the front edge of the recording paper 2 is surely attached to the front wall 17a of the separation claw 17 when the recording paper 2 is taken out from the paper feed cassette 3. When the recording paper 2 comes into contact with the separation pawl 17 and the recording paper 2 is hung on the separation pawl 17 in a stable manner, the reliability of the paper feeding operation is improved.

FIG. 4 shows a second embodiment. In this embodiment, the bottom end of the middle plate 18 is in contact with the surface of the uppermost recording paper 2 in the vicinity of the separating claw 17. The tubular body 20 is attached, and the curled region of the recording paper 2 is limited by the tubular body 20. The tubular body 20 is provided so as to be able to move up and down, and is urged downward by a compression coil spring 21. The compression coil spring 21 urges the tubular body 20 downward with a force larger than the curling force of the recording paper 2.

Therefore, in this embodiment, the tubular body 20 ascends and descends following the raising and lowering operation of the recording paper 2, and the tubular body 20 is always on the surface of the recording paper 2 regardless of the raising and lowering operation of the recording paper 2. Even if the pick-up roller 12 pushes down the recording paper 2 when the recording paper 2 is taken out from the paper feed cassette 3, the tubular body 20 is securely attached to the surface of the recording paper 2. The curled area of the recording paper 2 can be restricted by making contact.

FIG. 5 shows a third embodiment. In this embodiment, a roller 22 that comes into contact with the surface of the uppermost recording paper 2 near the separation claw 17 is provided at the front end portion of the intermediate plate 18. The curled area of the recording paper 2 is limited by the roller 22 attached. The roller 22 is rotatably and vertically movable, and is urged downward by a torsion coil spring 23. The torsion coil spring 23 urges the roller 22 downward with a force larger than the curl force of the recording paper 2.

Therefore, in this embodiment, the roller 22 moves up and down following the vertical movement of the recording paper 2, and the roller 22 always contacts the surface of the recording paper 2 regardless of the vertical movement of the recording paper 2. Similar to the second embodiment, the curl area of the recording paper 2 can be limited even if the recording paper 2 is pushed down by the picking roller 12 when the recording paper 2 is taken out of the paper feed cassette 3. Further, the roller 22 rotates with the operation of taking out the recording paper 2, and this rotation reduces the load at the time of taking out the recording paper 2.

FIG. 6 shows a fourth embodiment. In this embodiment, the paper feed cassette 3 is provided with an upper lid 24 and the upper surface of the upper lid 24 is made of a flexible material such as Mylar (trade name). The sheet 25 is adhered, and a rib 26 is formed on the lower surface of the flexible sheet 25 in the vicinity of the separation claw 17 so as to contact the surface of the uppermost recording paper 2. The rib 26 forms a curl area of the recording paper 2. It is becoming restricted. The rectangular hole 27 formed in the flexible sheet 25 is for escape of the picking roller 12.

Therefore, in this embodiment, the curl area of the recording paper 2 can be simply limited without providing a special member on the printer side.

In the above-described embodiment, the limiting member is always brought into contact with the surface of the recording paper 2, but the limiting member is provided near the separation claw 17 with a predetermined distance from the surface of the recording paper 2. However, the curl area of the recording paper 2 may be limited by contacting the surface of the recording paper 2 with the limiting member during the curling of the recording paper 2.

Further, in the above embodiment, the limiting member is provided on the middle plate 18 of the printer case 1 or the upper lid 24 of the paper feed cassette 3, but the present invention is not limited to this, and other cases such as the case of the paper feed cassette 3 are provided. The member may be provided with a limiting member.

[0026]

[Effect of the device]

 As described above, according to the paper feeding device of the present invention, since the limiting member for limiting the curl area of the recording paper is provided, the double feeding at the time of taking out the recording paper from the paper feeding cassette is more reliable. It has an excellent effect that it can be prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a printer to which a paper feeding device according to the present invention is applied.

FIG. 2 is a vertical sectional view taken along the line AA of FIG.

FIG. 3 is a vertical sectional view taken along the line BB of FIG.

FIG. 4 is a vertical sectional view of a printer showing a second embodiment.

FIG. 5 is a vertical sectional view of a printer showing a third embodiment.

FIG. 6 is a transverse sectional view of a printer showing a fourth embodiment.

[Explanation of symbols]

 2 Recording Paper 3 Paper Feed Cassette 12 Picking Roller 17 Separation Claw 19 Bottomed Cylindrical Part (Limiting Member)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroyuki Kojima, 934-13 Shikato, Yotsukaido, Chiba Prefecture Seikosha Chiba Works (72) Inventor, Takashi Mugo 934-13 Shikado, Yotsukaido, Chiba Seikosha Chiba Works

Claims (1)

[Scope of utility model registration request] 1. A paper feed cassette for containing a recording paper; a picking roller which is rotated while being pressed against the surface of the uppermost recording paper in the paper feed cassette to take out the recording paper from the paper feed cassette; Separation pawls provided on both sides of the front end of the paper feed cassette so as to engage with the front end corners of the recording paper and curling the recording paper when the recording paper is taken out of the paper feed cassette; A limiting member that is provided so as to face the surface of the uppermost recording sheet in the paper feeding cassette and that limits the curl area of the recording paper when the recording paper is taken out from the paper feeding cassette. A paper feeding device characterized by the above.