JP2006008289A - Paper feeding mechanism and printer using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding mechanism capable of carrying a sheet in high precision by naturally and smoothly biting a recording sheet between a paper feeding roller and a pressure roller and a printer using it. <P>SOLUTION: This paper feeding mechanism 1 is furnished with the paper feeding roller 2, the pressure roller 4, the recording sheet 8 free to contact with pressure and hold between this pressure roller 3 and the paper feeding roller 2 and a plurality of projections projected and formed on an outer peripheral surface of the paper feeding roller 2, a flange shaped collar 5 is projected and formed on the pressure roller 4, projected height of the collar 5 is set higher than height of the projection, a friction member 6 is supported on an outer peripheral surface of the collar 5 and rotation of this paper feeding roller 2 is transmitted to the pressure roller 4 through the friction member 6 when the paper feeding roller 2 is rotated and driven in a state where the pressure roller 4 is made contact with the paper feeding roller 2 with pressure. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a paper feed mechanism and a printer using the same, and more particularly to a paper feed mechanism capable of feeding a recording paper between a paper feed roller and a pressure roller and reliably feeding the paper with high accuracy, and the same. Regarding printers.

As shown in FIG. 3, the conventional paper feed mechanism 21 is provided with a cylindrical paper feed roller 22 having a predetermined diameter size. The paper feed roller 22 is made of a metal such as iron, and has a roller portion 22a. Protrusions 23 are formed on the outer peripheral surface by projecting a plurality of protrusions with a predetermined pitch dimension and height dimension in the circumferential direction and the axial direction. The paper feed roller 22 is provided with hard nickel plating or the like on the entire front surface.
The paper feed roller 22 is rotatably supported on the housing side of a printer (not shown) by rotating shafts 22b and 22b formed to protrude from both ends in the longitudinal direction.

Further, a pressure contact roller 24 is disposed in parallel with the paper feed roller 22 at the roller portion 22 a of the paper feed roller 22.
The pressure roller 24 is made of a metal such as iron, and rotary shafts 24b and 24b formed to protrude from both ends in the longitudinal direction of the roller portion 34a are rotatably supported on the housing side of the printer.
Further, in the pressing roller 24, the rotation shafts 24b and 24b are elastically biased by the coil spring 25, so that the roller portion 24a is pressed against the protrusion 23 formed on the roller portion 22a of the paper feed roller 22 with a predetermined pressing pressure. It has become.

A recording sheet 26 having a predetermined thickness is sandwiched between the paper feed roller 22 and the pressure roller 24 by pressure.
The recording paper 26 held in pressure contact between the paper feed roller 22 and the pressure contact roller 24 can be reciprocally conveyed by the rotation of the paper feed roller 22 with a plurality of protrusions formed on the protrusions 23 being stuck into the lower surface. It has become.
For example, when a desired image is printed on the recording paper 26, the recording paper 26 is conveyed to the printer-side printing unit by the rotation of the paper feed roller 22, whereby the desired image is printed on the recording paper 26. It is like that.

In such a conventional paper feeding mechanism 21, when the recording paper 26 is not pressed and clamped, the outer peripheral surface 24a presses against the plurality of protrusions of the protrusion 23, so that the protrusion is crushed and the recording paper There is a possibility that the amount of piercing to the recording medium 26 varies, and the conveyance of the recording paper 26 may vary.
As a countermeasure against this, as shown in FIG. 4, the conventional paper feed mechanism 31 has a pair of currants 34 b that protrude from the roller portion 34 a of the pressure contact roller 34. It is formed slightly higher than the height of the protrusion.
Therefore, even if the pressure roller 34 is elastically biased by the coil spring 25 and pressed against the paper feed roller 22, the plurality of protrusions of the protrusion 23 do not collide with the roller portion 34 a of the pressure roller 34, and the protrusion Can prevent crushing.

JP-A-4-216773 JP-A-11-79461

However, the conventional paper feed mechanism 31 rotates the paper feed roller 22 so that the leading end portion of the recording paper 26 is caught between the protrusion 23 and the roller portion 34a of the pressure roller 34 to be pressed and sandwiched. Since the currant 34b and the roller portion 22a of the paper feed roller 22 are made of metal, the pressure roller 34 may slip when the leading end of the recording paper 26 collides. As a result, the recording paper 26 having the leading end collided with the pressing roller 24 cannot smoothly bite the leading end between the paper feed roller 22 and the pressing roller 24.
For this reason, the recording paper 26 cannot be smoothly conveyed to the printing means side, and there is a possibility that a printing defect or the like may occur.

Further, in order to prevent the pressing roller 24 from slipping when the leading end of the recording paper 26 collides, the elastic force of the coil spring 25 is increased so that the pressing roller 34 is pressed against the paper feed roller 22 with a large pressing pressure. However, when the pressure contact pressure is increased, the nickel plating of the roller portion 22a of the paper feed roller 22 in the portion where the currant 34b is pressure contacted may be peeled off and foreign matter such as metal powder may be generated.
SUMMARY OF THE INVENTION The present invention solves the problems as described above, and enables a paper feeding mechanism that can smoothly and smoothly bite a recording paper between a paper feeding roller and a pressure contact roller so as to convey the paper with high accuracy, and a printer using the same. The purpose is to provide.

  As a first means for solving the above problems, a paper feed mechanism of the present invention includes a paper feed roller having an outer shape that is cylindrical and capable of being driven to rotate, a rotatable pressure contact roller that can be pressed against the paper feed roller, A recording paper that can be pressed and sandwiched between a pressure roller and the paper feed roller, and a plurality of protrusions that are formed to protrude from the outer peripheral surface of the paper feed roller and can be pierced on one surface of the recording paper, Either one of the paper feed roller or the pressure contact roller is formed with a hook-shaped curan, and the projecting height of the curan is formed higher than the height of the protrusion. When the paper feed roller is rotationally driven in a state where the member is supported and the pressure contact roller is in pressure contact with the paper feed roller, the rotation of the paper feed roller is transmitted to the pressure contact roller through at least the friction member. It is characterized in.

  Further, as a second means for solving the above-mentioned problem, the friction member is made of an elastically deformable member.

  As a third means for solving the above-mentioned problem, the currant is formed on the pressure roller side, and the friction member is formed in a ring shape in the circumferential direction of the outer peripheral surface of the curan. When the recording paper is sandwiched between the paper feed roller and the pressure contact roller and is fitted and supported by a groove having a predetermined depth and protrudes by a predetermined dimension from the outer peripheral surface of the currant, Is separated from the outer peripheral surface of the paper feed roller, and when the recording paper is not sandwiched between the paper feed roller and the pressure contact roller, the curan is brought into contact with the outer peripheral surface of the paper feed roller. It is characterized by becoming.

  Further, a printer using the paper feed mechanism of the present invention as a fourth means for solving the above problem includes the paper feed mechanism according to any one of claims 1 to 4 and is capable of printing on the recording paper. The pressure contact roller that has a printing unit and does not sandwich the recording paper with the paper feed roller is rotatable by transmitting the rotation of the paper feed roller through at least the friction member. The recording paper sandwiched between the paper feed roller and the pressure roller is conveyed to the printing means by the rotating paper feed roller and the pressure roller so that a desired image can be printed. It is characterized by being.

In the paper feed mechanism of the present invention, the protrusion height of the currant is formed higher than the height of the protrusion, a friction member is supported on the outer peripheral surface of the currant, and the paper feed roller is in a state where the press roller is pressed against the paper feed roller. When the rotation of the paper is driven, the rotation of the paper feed roller is transmitted to the pressure contact roller through at least the friction member, so that the leading edge of the recording paper can be smoothly and effortlessly engaged between the paper feed roller and the pressure contact roller. .
Therefore, the recording paper can be conveyed to the printing unit with high accuracy.

Further, since the friction member is made of an elastically deformable member, when the pressure roller is pressed against the paper feed roller, the friction member is elastically deformed, and both the curan and the friction member are pressed against the paper feed roller. Pressure contact against the paper feed roller applied to the currant can be reduced. For this reason, it is possible to prevent the paper feed roller from being peeled off and the like, thereby eliminating the occurrence of foreign matters.
Further, it is possible to eliminate the variation in the gap between the pressure contact roller and the paper feed roller, and it is possible to eliminate the variation in the recording paper biting between the paper feed roller and the pressure contact rotor.

  When the recording paper is sandwiched between the paper feed roller and the pressure roller, the curan is separated from the outer peripheral surface of the paper feed roller, and the recording paper is sandwiched between the paper feed roller and the pressure roller. When not, the curan is in contact with the outer peripheral surface of the paper feed roller, so that the press roller can securely hold the recording paper between the paper feed roller and the outer peripheral surface of the paper feed roller. There is no collision with the formed projections.

  In the printer using the paper feed mechanism of the present invention, the rotation of the paper feed roller is transmitted through at least the friction member when the recording paper is not sandwiched between the paper feed roller and the pressure contact roller. The recording paper sandwiched between the paper feed roller and the pressure contact roller is conveyed to the printing means by the rotating paper feed roller and the pressure contact roller so that a desired image can be printed. Therefore, the recording paper that has been conveyed can be smoothly caught between the paper feed roller and the pressure roller, and the recording paper can be conveyed to the printing means side with high accuracy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 is a front view for explaining a paper feed mechanism of the present invention, and FIG. 2 is a front view when a recording paper is pressed and sandwiched by the paper feed mechanism of the present invention.
A printer according to an embodiment of the present invention will be described with reference to the drawings. A printing unit including a print head (not shown) is provided, and a paper feed mechanism 1 as shown in FIG. Is arranged. The paper feed mechanism 1 is provided with a paper feed roller 2 made of metal on the lower side of the figure, and the paper feed roller 2 is formed with a roller portion 2a having a cylindrical shape with a predetermined diameter. Arranged.
Further, the paper feed roller 2 has rotating shafts 2b and 2b protruding from left and right end portions in the longitudinal direction of the roller portion 2a.

The rotary shafts 2b and 2b are supported by bearings formed in a housing on the printer (not shown) side, and can be driven to rotate in both the left and right directions by a drive source such as a stepping motor.
Further, on the outer peripheral surface of the roller portion 2a, a protrusion forming portion 3 having a plurality of protrusions formed to protrude in a circumferential direction and an axial direction with a predetermined height dimension and a pitch dimension has a predetermined width dimension, for example, It is formed in two places near the rotating shafts 2b and 2b on the left and right in the figure. The paper feed roller 2 is subjected to hard plating such as nickel plating on the entire outer periphery.

On the upper side in the figure facing the roller portion 2a of the paper feed roller 2, a pressure contact roller 4 made of metal or the like having a roller portion 4a having a cylindrical outer shape and a length B is disposed.
The pressure roller 4 is formed to have substantially the same length as the paper feed roller 2 and is disposed in parallel with the longitudinal direction of the paper feed roller 2.
Between the paper feed roller 2 and the pressure contact roller 4, there is a paper conveyance area of size A corresponding to the width size of the recording paper 6 described later, and the length of the roller portion 4a is dimension A. The dimension B is longer than the sheet conveyance area.

Further, the protrusion forming portions 3 of the paper feed roller 2 are formed at two locations on the outer peripheral surface of the outer roller portion 2a within the range of the paper transport area of dimension A.
Further, rotation shafts 4b and 4b are formed to project outward from both ends in the longitudinal direction of the roller portion 4a having the dimension B of the pressure roller 4, and the rotation shafts 4b and 4b are supported by a casing on the printer side. And can be rotated freely.
In addition, a pair of bowl-shaped currants 5 and 5 are fixed to the transport roller 4 by press-fitting or the like with a roller portion 4a having a dimension B interposed therebetween.

The currant 5 is formed in a bowl shape with a diameter larger than the diameter of the roller portion 4a, and the protrusion height from the roller portion 4a is higher than the plurality of protrusion heights of the protrusion forming portion 3, and photographic paper to be described later The recording paper 8 is formed to be smaller than the thickness dimension thereof.
A groove 5a having a predetermined depth and width is formed on the outer peripheral surface of the currant 5, and a friction member 6 made of urethane rubber or the like and having excellent wear resistance is fitted and supported in the groove 5a. Yes. The friction member 6 fitted and supported in the groove 5 a has an outer diameter that is larger than the outer diameter of the currant 5, and protrudes from the outer peripheral surface of the currant 5 by about 0.1 mm, for example.

Further, the rotary shafts 4 b and 4 b at both ends of the pressure contact roller 4 are elastically biased by the coil springs 7 and 7. Therefore, the currants 5 and 5 are in pressure contact with the outer peripheral surface of the roller portion 2 a of the paper feed roller 2. The friction member 6 at this time is elastically deformed by the urging force of the coil spring 7 so that the currant 5 and the friction member 6 are in pressure contact with the roller portion 2a. When the paper feed roller 2 is rotationally driven in a state where the pressure roller 4 is in pressure contact with the paper feed roller 2, the paper is caused by friction generated between the friction member 6 and the outer peripheral surface of the roller portion 2 a of the paper feed roller 2. The rotation of the feed roller 2 is transmitted to the pressure contact roller 4.
Therefore, the pressure contact roller 4 rotates without slipping with respect to the paper feed roller 2.

Further, when the currant 5 and the friction member 6 are pressed against the outer peripheral surface of the paper feed roller 2, a predetermined gap is formed between the tops of the plurality of protrusions of the protrusion forming portion 3 and the outer peripheral surface of the roller portion 4 a of the pressure roller 4. Is to be formed.
Therefore, it can prevent that the some protrusion of the protrusion formation part 3 is crushed, or the outer peripheral surface of the roller part 4a is damaged by a some protrusion.
In addition, a recording paper 8 having a thickness of 0.2 to 0.3 mm, for example, having a thickness of 0.2 to 0.3 mm is sandwiched between the paper feeding roller 2 and the pressure roller 4 in a paper conveyance area having a dimension A. It has become so.

The recording paper 8 held in pressure contact between the paper feed roller 2 and the pressure roller 4 slips the recording paper 8 by the plurality of protrusions of the protrusion forming portion 3 biting into one surface 8a on the lower surface side in the figure. It is possible to carry it without doing it.
The recording paper 8 has a printing surface 8b on the upper surface side, and a desired image can be printed on the printing surface 6b by printing means on the printer (not shown) side described later.

  When the recording paper 8 is sandwiched between the paper feed roller 2 and the pressure roller 4, the currant 5 and the friction member 6 are separated from the outer peripheral surface of the paper feed roller 2, so that a gap of dimension C is formed. Since it is formed, the plurality of protrusions of the protrusion forming portion 3 can be surely bited into the one surface 8 a that is the lower surface side of the recording paper 8.

A printer (not shown) using the paper feed mechanism 1 of the present invention as described above is a drive source in which the rotation shaft 2b of the paper feed roller 2 is supported by a bearing on the housing (not shown) side. The paper feed roller 2 can be driven to rotate by a stepping motor or the like.
In addition, the pressure roller 4 has a rotating shaft 4b that is elastically biased by the coil spring 7 supported by a bearing on the housing side.

Further, the recording paper 8 is stored in a paper feeding cassette in a state where a plurality of recording papers are stacked, and the recording paper 8 stored in the paper feeding cassette is separated one by one by the rotation of the paper feeding roller. And the pressure contact roller 4 so as to be held in pressure contact with each other.
Further, in the vicinity of the paper feed mechanism 1 of the present invention, a printing means (not shown) comprising a print head is disposed, and the recording 6 conveyed to the printing means by the paper feed roller 2 and the pressure contact roller 4 includes A desired image can be printed.

The printing operation of the printer using the paper feed mechanism 1 of the present invention will be described. When the recording paper 8 is conveyed from the paper feed cassette to the rotating paper feed roller 2 and the pressure roller 4 by the paper feed roller. The plurality of protrusions of the protrusion forming portion 3 are stuck into one surface 8 a of the leading end portion of the recording paper 8, and the leading end of the recording paper 8 is interposed between the paper feed roller 2 and the pressure roller 4 rotated by the friction of the friction member 6. The part can be bitten smoothly and smoothly. The pressure roller 4 rides on the printing surface 8 b of the recording paper 8, and the recording paper 8 is pressed and sandwiched between the paper feeding roller 2.
At this time, the friction member 6 is separated from the outer peripheral surface of the paper feed roller 2 to form a gap of dimension C.

Thereafter, the paper feed roller 2 is driven to rotate by a predetermined number of steps by a driving source such as a stepping motor to cue the recording paper 8, and the printing start position of the recording paper 8 is set on the print head as a printing means. Aligned.
Then, the printing unit is driven to start image printing on the recording paper 8 from the printing start position, and a desired image is printed on the printing surface 8 b of the recording paper 8.
The recording paper 8 on which the image printing has been completed is released from the pressure nipping between the paper feeding roller 2 and the pressure roller 4 by the rotation of the paper feeding roller 2, and the printed recording paper 8 is discharged from the printer. .

In such a printer using the paper feed mechanism of the present invention, when the leading end of the recording paper 8 is bitten between the paper feed roller 2 and the transport roller 4, the pressure roller 4 is surely held by the friction of the friction member 6. Can be rotated.
Therefore, the leading edge of the recording paper 8 can be smoothly and smoothly bitten between the paper feed roller 2 and the transport roller 4.

In the embodiment of the present invention, when the pressure roller 4 is pressed against the paper feed roller 2, the friction member 6 is elastically deformed, and both the currant 5 and the friction member 6 are pressed against the paper feed roller 2. However, the paper feed roller 2 and the currant 5 may have a gap so that only the friction member 6 is in pressure contact with the paper feed roller 2.
That is, the pressure roller 4 that is in pressure contact with the paper feed roller 2 may be any one that at least the friction member 6 is in pressure contact with the paper feed roller 2. The press roller 4 only needs to be able to transmit the rotation of the paper feed roller 2 through at least the friction member 6.

Further, although the description has been given of the case where the currant 5 is formed on the pressure roller 4, the currant 5 may be formed on the paper feed roller 2.
That is, it is sufficient if the currant 5 is formed on either the paper feed roller 2 or the pressure roller 4.
Further, it has been described that when the recording paper 8 is sandwiched between the paper feed roller 2 and the pressure contact rotor 4, a gap of dimension C is formed between the friction member 6 and the paper feed roller 2. 6 may contact the paper feed roller 2.
That is, when the recording paper 8 is sandwiched between the paper feed roller 2 and the pressure contact rotor 4, the currant 5 may be separated from the paper feed roller 2.

It is a front view of the paper feed mechanism regarding the present invention. It is principal part sectional drawing explaining operation | movement of the paper feed roller regarding this invention. It is a perspective view of the conventional paper feed mechanism. It is the front of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feed mechanism 2 Paper feed roller 2a Roller part 2b Rotating shaft 3 Protrusion forming part 4 Pressure roller 4a Roller part 4b Rotating shaft 5 Curan 6 Friction member 7 Coil spring 8 Recording paper
8a One side 8b Print side

Claims (4)

  A paper feed roller having a cylindrical outer shape, which can be rotationally driven, a rotatable pressure contact roller which can be pressed against the paper feed roller, and a recording paper which can be pressed and sandwiched between the pressure contact roller and the paper feed roller; And a plurality of protrusions that protrude from the outer peripheral surface of the paper feed roller and can be pierced on one surface of the recording paper, and either one of the paper feed roller or the pressure contact roller has a bowl-shaped currant. A protrusion is formed, the protrusion of the curan is formed higher than the protrusion, the friction member is supported on the outer peripheral surface of the curan, and the paper contact roller is pressed against the paper feed roller. When the feed roller is driven to rotate, the rotation of the paper feed roller is transmitted to the pressure contact roller through at least the friction member.   The paper feeding mechanism according to claim 1, wherein the friction member is made of an elastically deformable member.   The currant is formed on the pressure roller side, and the friction member is formed in a ring shape and fitted and supported in a groove having a predetermined depth formed in the circumferential direction of the outer peripheral surface of the curan. When the recording paper is sandwiched between the paper feed roller and the pressure contact roller, the curan is separated from the outer peripheral surface of the paper feed roller, and the paper feed 3. The currant is configured to abut on an outer peripheral surface of the paper feed roller when the recording paper is not sandwiched between a roller and the pressure roller. Paper feed mechanism. 5. The pressure contact when the paper feeding mechanism according to any one of claims 1 to 4 is provided, printing means capable of printing on the recording paper, and the recording paper is not sandwiched between the paper feeding rollers. The roller is rotatable by transmitting the rotation of the paper feed roller through at least the friction member, and the recording paper sandwiched between the paper feed roller and the pressure roller is the rotating paper. A printer characterized in that a desired image can be printed by being conveyed to the printing means by a feed roller and the pressure roller.

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