JP2009173432A - Paper feeding mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding mechanism capable of achieving simplification and reduction in the size and preventing skew. <P>SOLUTION: The paper feeding mechanism is provided with paper feeding means P1, P2 capable of pressing pressure contact rollers 5, 19 supported between a pair of roller support members 6, 20 on paper feeding rollers 4, 18 by elastically energizing lower end sides of the pair of roller support members 6, 20 rockingly arranged on upstream and downstream sides in the paper carrying direction by elastic members 15, 21. A pressure contact release mechanism P3 which oscillates the roller support members 6, 20 resisting to energizing force of the elastic members 15, 21 by rotating a drive shaft 7 supported between chassis at a predetermined angle by drive force of a drive source 8 and releases pressure contact of the respective pressure contact rollers 5, 19 with respect to the paper feeding rollers 4, 18 is arranged on either one of downstream sides of the means P1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed mechanism suitable for mounting on a recording apparatus in which no blank space is provided on a recording paper and is suitable for mounting on a recording apparatus. About.

  The conventional paper feed mechanism shown in Patent Document 1 has a first paper feed roller that can be driven to rotate, and a first pressure roller that can be pressed against the first paper feed roller, and the conveyance direction of the recording paper during printing The first paper feed means disposed downstream of the position of the print means for performing desired printing on the recording paper, the second paper feed roller that can be driven to rotate, and the second paper feed roller can be pressed against each other. And a second paper feed means disposed upstream of the print means placement position in the transport direction of the recording paper during printing, and the recording paper is fed to each of the paper feed means. In FIG. 2, the paper feed roller and the pressure contact roller are in pressure contact with each other, and the paper feed rollers are rotated to convey the paper.

  The first paper feed means is provided with a pair of first roller support members that rotatably support both ends of the rotation shaft of the first pressure roller, and the second paper feed means includes the first paper support means. A pair of second roller support members that rotatably support both end portions of the rotary shaft of the two pressure contact rollers are disposed. Each roller support member is formed with a roller support portion capable of rotatably supporting the rotation shaft of each pressure contact roller on one end portion side, and the other end portion side is elastically biased by the elastic member. .

  The first paper feeding means includes a drive shaft parallel to the axial direction of the first pressure roller, and a drive source capable of rotating the drive shaft by a predetermined angle. The drive source includes a gear. A connecting shaft is connected through a group, and this connecting shaft is rotatable in forward and reverse directions and extends in parallel with the drive shaft. A connecting gear is fixed to the connecting shaft.

  The first pressure roller is connected to a pressure release mechanism capable of releasing the pressure contact with the paper feed roller. In the pressure release mechanism, the connection gear and a drive gear that is fixed to a substantially central portion of the drive shaft and meshes with the connection gear are disposed, and when the connection shaft is rotated by the drive source, The drive shaft is rotated by a predetermined angle via the connecting gear and the drive gear, so that the pressure contact of the first pressure roller with respect to the first paper feed roller can be released, and the pressure release mechanism includes the drive shaft. Is rotated by a predetermined angle, the roller support member is rotated against the urging force of the elastic member with the rotation support portion supported on the printer body side as a fulcrum, and the second pressure contact roller is the second pressure contact roller. It is separated from the paper feed roller by a predetermined amount.

  That is, a first drive link capable of rotationally driving the first roller support member of the first paper feed means and a second roller support member of the second paper feed means at both ends in the axial direction of the drive shaft. A second drive link that can be driven to rotate is supported.

  Near the both ends in the axial direction of the drive shaft, a first cam member that can be fitted and rotated in a first cam hole formed in the first drive link, and a second cam formed in the second drive link A second cam member that is fitted in the hole and is rotatable is pivotally fixed. The first drive link has the first cam hole formed on one end side, and can rotatably support the other end side of the first roller support member on the other end side. When the first link support portion is formed and the drive shaft is rotationally driven by a predetermined angle, the first cam member rotates in the first cam hole, and the first roller support member is interposed via the first drive link. Rotates with the first rotation support portion as a fulcrum, so that the first pressure contact roller can be brought into contact with and separated from the first paper feed roller.

  The second drive link has a second cam hole formed on one end side and a second end that can rotatably support the other end side of the second roller support member on the other end side. When a two-link support portion is formed and the drive shaft is rotationally driven by a predetermined angle, the second cam member rotates in the second cam hole, and the second roller support member is interposed via the second drive link 17. Is rotated with the second rotation support portion as a fulcrum, so that the second pressure contact roller can contact and separate from the second paper feed roller.

  As described above, in the paper feed mechanism in which the pressure contact driving mechanism is disposed at the substantially central portion in the axial direction of the pressure contact roller, the paper feed roller is brought into pressure contact with the paper feed roller substantially uniformly at both ends in the axial direction of the pressure contact roller. And skew of the recording paper can be prevented.

JP 2007-45577 A

  However, in the paper feeding mechanism described above, there are many arrangements of gear groups, cams, links, etc. in addition to the connecting shaft on which the connecting gear is pivotally supported, the configuration is complicated, and the manufacturing cost increases. The problem is that it is difficult to reduce the size of the apparatus.

  The present invention has been made to solve the above-described problems. The number of parts is reduced, the manufacturing cost is reduced, the mechanism is simplified, and the size is reduced. An object is to provide a possible paper feeding mechanism.

  In order to solve the above-described problems, the paper feed mechanism according to the present invention has a pair of bell crank-shaped roller support members formed at the corners on the upstream side and the downstream side of the printing means in the recording paper conveyance direction during printing. The roller support member is slidably disposed on the chassis with the rotation support portion formed as a sway center, and the lower end side of the roller support member is elastically biased by the elastic member to the opposite side to the direction in which the printing unit is disposed. And a paper feed means for allowing the pressure contact roller supported between the pair of roller support members to be pressed against the paper feed roller disposed between the chassis, and disposed upstream of the recording paper transport direction. A drive shaft supported between the chassis is driven either on the upstream side of the paper feeding means, or on the downstream side of the paper feeding means disposed on the downstream side in the recording paper conveyance direction. The roller support member in each paper feeding means is swung against the urging force of the elastic member by rotating it by a predetermined angle by the driving force of the pressure, and a pressure release mechanism for releasing the pressure contact of the pressure roller with respect to the paper feed roller is arranged. It was established.

  Specifically, the pressure release mechanism includes a cam member having a bonded structure in which the drive shaft is fixed to both axial ends of the drive shaft by rotating the drive shaft by a predetermined angle. The first control cam is engaged with a first roller formed on a link plate that is erected on one end side of a long link member so as to be orthogonal to the drive shaft, and the link member is transported through the recording sheet. The lower end portion of the roller support member in the other paper feeding means located in the engagement hole formed on the other end side of the link member is pulled toward the printing means side, and the rotation support portion And the second control cam of the cam member is engaged with a second roller formed at the lower end of the roller support member in one paper feeding means disposed in the vicinity of the drive shaft. Let the lower end to the printing means side Pressure, characterized in that oscillating the rotation supporting portion as a fulcrum.

  According to the paper feed mechanism of the present invention, the number of components such as shafts, gears, cams, links, and the like can be greatly reduced to reduce the manufacturing cost, and the mechanism can be simplified and downsized. Moreover, the pressure release mechanism performs the pressure contact of the pressure roller with respect to the paper feed roller and the release thereof by using roller support members and links respectively disposed on both ends in the axial direction of the pressure roller of each paper feed means. It is possible to uniformly press the paper feed roller at both ends in the axial direction. Accordingly, skew feeding can be prevented and recording paper can be conveyed with high accuracy.

  Hereinafter, the paper feed mechanism of the present invention will be described with reference to FIGS.

  First, as shown in FIG. 1, the paper feed mechanism 1 of the present invention has a printing means 2 capable of printing a desired image on a recording paper (not shown) such as a photographic paper at an intermediate portion in the recording paper conveyance path. Is arranged.

  The printing means 2 is composed of a thermal head (not shown) and a cylindrical platen roller 3 that can be pressed against the thermal head.

  The recording paper can be reciprocally conveyed in the directions indicated by arrows A and B in the drawing, and a first paper feed is provided on the downstream side of the left side of the platen roller 3 in the conveying direction indicated by the arrow A of the recording paper. Means P1 is provided, and second paper feeding means P2 is provided on the upstream side of the platen roller in the conveyance direction of the arrow A of the recording paper.

  In the first paper feeding means P1, the first paper feeding roller 4 is rotatably disposed between the chassis (not shown) at the lower side of the recording paper conveyance path, orthogonal to the recording paper conveyance direction. A first pressure roller 5 that can be pressed against the first paper feed roller 4 is disposed on the upper side of the recording paper conveyance path. The first pressure roller 5 is configured such that the rotation shafts 5a at both end portions in the axial direction are supported by a pair of first roller support members 6 having a substantially L-shaped bell crank shape, and are rotatable.

  The first roller support member 6 is formed in the bent portion so that one of the first roller support member 6 hangs downward from the bent portion of the bell crank shape and the other is directed toward the printing means. The 1-turn support portion 6c is swingably disposed on the chassis with the swing center. A first roller support portion 6a for supporting the rotation shaft 5a of the first pressure contact roller 5 is formed at the tip of the portion extending to the printing means 2 side (hereinafter referred to as the upper end portion), and extends downward. A hook portion 6b is formed at the leading end portion (hereinafter referred to as the lower end portion) of the portion to be projected to the side opposite to the direction in which the printing means 2 is disposed. Further, a locking portion 6d is formed at the lower end portion, and a first elastic member 15 made of a tension coil spring is locked to the locking portion 6d, so that the lower end portion of the first roller support member 6 is secured. The side is always elastically biased in the direction of arrow A. Therefore, the first pressure contact roller 5 supported by the first roller support portion 6 a of the first roller support member 6 can be brought into pressure contact with the first paper feed roller 4 by the urging force of the first elastic member 15. Further, the hook portion 6 is locked to a locking hole 26 of a link member 25 constituting a press contact release mechanism P3 described later by the urging force of the first elastic member 15, and one end of the link member 25 is held. It is configured as follows.

  Similarly, for the second paper feeding means P2, a second paper feeding roller 18 is disposed below the recording paper conveyance path, and a second pressure roller 19 is disposed above the recording paper conveyance path. The second pressure roller 19 is rotatable with the rotation shafts 19a at both ends in the axial direction being supported by a pair of substantially L-shaped second roller support members 20.

  The second roller support member 20 also has the second rotation support portion 20c formed in the bent portion so that the upper end portion thereof faces the direction of the printing means, similarly to the first roller support member 6. As a swing center, it is swingably disposed in the chassis on the recording apparatus side. A second roller support portion 20a that supports the rotating shaft 19a of the second press contact roller 19 is disposed on the upper end side. Further, a locking portion 20d is formed at the lower end portion, and a second elastic member 21 made of a tension coil spring is locked to the locking portion 20d, so that the lower end portion of the second roller support member 20 is secured. The second pressure roller 19 is always urged elastically in the direction of arrow B, and the second pressure roller 19 supported by the second roller support portion 20a of the second roller support member 20 is urged by the second elastic member 21 to move the second paper feed roller 18. It is possible to press. Further, a second roller 30 that engages with a second control cam 13 of a second cam member 11 that constitutes a press-contact release mechanism P3 described later is formed at the lower end portion of each second roller support member 18 so as to be opposed. ing.

  In the paper feeding mechanism 1 of the present embodiment, the paper feeding in each paper feeding means P1 and P2 is upstream of the second paper feeding means P2 disposed upstream in the recording paper conveyance direction during recording. A pressure release mechanism P3 for releasing the pressure contact of the pressure rollers 5 and 19 with respect to the rollers 4 and 18 is provided.

  In the pressure release mechanism P3, a drive shaft 7 parallel to the axial direction of the second paper feed roller 18 is rotatably disposed between chassis (not shown), and the drive shaft 7 can be rotated at a predetermined angle. A motor 8 as a drive source is attached to the printer main body 9 side.

  A first cam member 10 is pivotally supported near both ends of the drive shaft 7 in the axial direction. The drive shaft 7 outside the first cam member 10 has a structure in which two plate cams are bonded together. The made second cam member 11 is pivotally supported.

  As shown in FIG. 2, the second cam member 11 includes a first control cam 12 that can adjust the pressure contact and release of the first pressure contact roller 5 with respect to the first paper feed roller 4 in the first paper feed means P1. The second control cam 13 that can adjust the press-contact and release of the second press-contact roller 19 with respect to the second paper-feed roller 20 in the second paper-feed means P2 is approximately the position of the circumferential portion having the maximum diameter. It is formed by pasting together in such a manner that the contact portion is changed from a portion having the maximum diameter to a peripheral portion having a small diameter for a while by a difference of 270 ° and rotation in different directions. Then, by the rotation of about 270 ° accompanying the rotation of the drive shaft 7, the first pressure roller 5 is brought into pressure contact with the first paper feed roller 4 in the first paper feed means P1, and in the second paper feed means P2, In the state where the pressure contact of the second pressure roller 19 with respect to the second paper feed roller 18 is released (first state), and in the first paper feed means P1 and the second paper feed means P2, the pressure rollers 5 and 19 are fed by paper. In the state in which the rollers 4 and 18 are in pressure contact (second state) and in the first paper feed means P1, the pressure contact of the first pressure contact roller 5 to the first paper feed roller 4 is released, and the second paper feed means P2 In FIG. 3, three modes are created, in which the second pressure roller 19 is in pressure contact with the second paper feed roller 18 (third state).

  The pressure release mechanism P3 has a pair of long link members 25 extending in the recording sheet conveyance direction. At the downstream end portion of the link member 25 in the recording sheet conveyance direction during recording, the hook portion 6b of the first roller support member 6 described above is engaged, and one end side of the link member 25 is supported. A locking hole 26 is formed as a space for allowing the first roller support member 6 to swing. A horizontally long plate-like link plate 27 is disposed on the upstream upper surface of each link member 25 in the recording sheet conveyance direction at the time of recording, along the recording sheet conveyance direction. . A laterally long elliptical cam hole 28 is formed at the center of the link plate 27, and the other end of the link member 25 is formed by fitting the first cam member 10 into the cam hole 28. While holding the side, the link member 25 can be slid in the longitudinal direction of the cam hole 28.

  A first roller 29 that engages with the first control cam 12 constituting the second cam member 11 protrudes from the outer surface of the link plate 27 at the downstream end in the recording sheet conveyance direction during recording. Is formed. As shown in FIGS. 3 to 5, the first roller 29 has the drive shaft in relation to the position of the second roller 30 when the second pressure roller 19 is in pressure contact with the second paper feed roller 20. 7, the first control cam 12 of the second cam member 11 supported by the shaft 7 is not engaged with the first roller 29, and the second control cam 13 is not engaged with the second roller 30. It is assumed that the position of the second paper feed means P2 is adjusted so that both the pressure contact rollers 5 and 19 are in pressure contact with the paper feed rollers 4 and 18 (second state).

  In this embodiment, from this second state, the motor 8 is driven to rotate the drive shaft 7 clockwise by a predetermined angle, and as shown in FIGS. Is engaged with the second roller 30, the lower end portion of the second roller support member 20 is pressed toward the printing means with the cam peripheral surface having a large diameter, and the second roller support member 20 is rotated. By rotating the supporting portion 20c against the urging force of the second elastic member 21 with the supporting portion 20c as a fulcrum, the second pressure roller 19 is separated from the second paper feeding roller 18 by a predetermined dimension in the second paper feeding means P2. The first state described above can be obtained. At this time, since the first control cam 12 is not engaged with the first roller 29, the first elastic member 15 locked to the lower end portion of the first roller support member 6 in the first paper feeding means P1. Due to the elastic biasing force, the first pressure roller 5 is brought into pressure contact with the first paper feed roller 4.

  Further, from the second state, the motor 7 is further driven to rotate the drive shaft 7 clockwise by a predetermined angle, and the peripheral surface of the first control cam 12 is moved to the first position as shown in FIGS. One link 29 is engaged, and the link plate 27 is pressed to the upstream side in the recording sheet conveyance direction during recording by a cam peripheral surface having a large diameter. Then, the link member 25 is slid to the upstream side in the recording sheet conveyance direction during recording along the recording sheet conveyance path via the link plate 27, and is formed on one end side of the link member 25. The lower end portion of the first roller support member 5 located in the stop hole 26 is pulled toward the printing means, and the first roller support member 5 resists the biasing force of the first elastic member 15 with the rotation support portion 6c as a fulcrum. By rotating the first pressure contact roller 5, the first pressure contact roller 5 can be brought into the third state described above, which is separated from the first paper feed roller 4 by a predetermined dimension. At this time, since the second control cam 13 is not engaged with the second roller 30, the second elastic member 21 locked to the lower end portion of the second roller support member 20 in the second paper feeding means P1. Due to the elastic biasing force, the second pressure roller 19 is brought into pressure contact with the second paper feed roller 18.

  Next, the recording paper transport operation in the paper feed mechanism 1 using the pressure release mechanism P3 will be described.

  In the paper feeding mechanism 1, the recording paper is fed from the front side where the first paper feeding means P1 is disposed, and is temporarily recovered to a predetermined position on the rear side where the second paper feeding means P2 is disposed. After cueing, desired recording is performed in the printing means 2. Therefore, at the time of paper feeding, the recording paper is supplied starting from the rear end side. In the case of color recording or the like, the above-described operation is repeated according to the number of inks used, and finally the paper is discharged to the front side in a state where desired recording is performed.

  In such a paper feed mechanism 1, first, at the time of feeding the recording paper, between the first paper feed roller 4 and the first pressure contact roller 5 of the first paper feed means P 1 disposed on the front side, In order to form a gap sufficient to position the recording paper, the motor 8 is driven to rotate the drive shaft 7 by a predetermined angle to obtain the above-described third state.

  In this state, when it is detected by a sensor (not shown) that the rear end portion of the recording paper is inserted between the first paper feed roller 4 and the first pressure roller 5, the motor 8 is driven to drive the drive shaft 7. Is rotated by a predetermined angle to be in the first state described above, and the first pressure contact roller 5 is moved to the first paper feed roller 4 by the elastic biasing force of the first elastic member 15 locked to the lower end portion of the first roller support member 6. The recording paper is clamped (nip). Then, the first paper feed roller 4 is rotated by a driving force of a driving source (not shown), and the recording paper is upstream of the recording paper transport direction during recording (hereinafter, this direction is simply referred to as “upstream side”, and the opposite direction. Send the direction to simply “downstream”.

  Then, a sensor (not shown) and the second paper feed roller 18 are rotated to indicate that the rear end portion of the recording paper is inserted between the second paper feed roller 18 and the second pressure roller 19 of the second paper feed means P2. When detected by counting the number of drive steps of the motor to be driven, etc., the motor 8 is driven to rotate the drive shaft 7 by a predetermined angle to obtain the second state described above, and the leading end side of the recording paper is the first paper feed means. The recording paper is fed further upstream by rotating the paper feeding rollers 4 and 18 of the paper feeding means P1 and P2 while pinching at P1 and holding the rear end side by the second paper feeding means P2.

  Before the leading edge of the recording paper comes out of the nipping between the first paper feed roller 4 and the first pressure roller 5 of the first paper feed means P1 (this timing is controlled by the number of driving steps of the first paper feed roller 4). The motor 8 is driven to rotate the drive shaft 7 by a predetermined angle to the third state described above, and the first paper feed roller 4 and the first pressure roller 5 of the first paper feed means P1 And the recording paper is fed further upstream only by the rotational driving force of the second paper feed roller 18 of the second paper feed means P2.

  Then, the leading end of the recording sheet is positioned upstream from the recording position where the printing unit 2 is disposed, and the head is moved down, and the thermal head constituting the printing unit 2 is headed down to the platen roller 3. To perform desired recording based on the recording information. At the beginning of recording, the recording paper is conveyed by the rotational driving force of the second paper feeding roller 8 and the rotational driving force of the platen roller 3 in the second paper feeding means P2.

  When the fact that the leading edge of the recording paper is located downstream of the first paper feeding means P1 is detected by a sensor (not shown) or by counting the number of driving steps of the motor that rotationally drives the second paper feeding roller, The motor 8 is driven to rotate the drive shaft 7 by a predetermined angle to the second state described above, the leading end side of the recording paper is sandwiched by the first paper feeding means P1, and the rear end side is second paper feeding means P2. , The recording paper is fed further downstream by rotating the paper feeding rollers 4 and 18 of P1 and P2 of each paper feeding means.

  Then, before the trailing edge of the recording paper comes out of the nipping by the second paper feeding roller 18 and the second pressure roller 19 of the second paper feeding means P2 (this timing is managed by the number of driving steps of the second paper feeding roller). The motor 8 is driven to rotate the drive shaft 7 by a predetermined angle to the above-mentioned first state, and the second paper feed roller 18 and the second pressure roller 19 of the second paper feed means P2 And the recording paper is fed further downstream by the rotational driving force of the first paper feeding roller 4 of the first paper feeding means P1 and the rotational driving force of the platen roller 3.

  When the recording of the trailing edge of the recording paper is completed, the thermal head is raised and the pressure contact with the platen roller 3 is released. Then, the recording paper is fed further downstream by the rotational driving force of the first paper feed roller 4 of the first paper feed means P1.

  By repeating this operation and printing an image of a different color on the already formed image, a desired color image can be printed on the recording paper.

  As described above, according to the paper feed mechanism of the present embodiment, the configuration of the pressure release mechanism P3 is extremely simple, so that the number of arrangements of shafts, gears, cams, links, and the like can be greatly reduced as the paper feed mechanism. Thus, the manufacturing cost can be reduced, and the mechanism can be simplified and downsized.

  Moreover, the pressure release mechanism P3 supports the pressure contact of the pressure rollers 5 and 19 with respect to the paper feed rollers 4 and 18, and roller support disposed on both ends in the axial direction of the pressure rollers 5 and 19 of the paper feed means P1 and P2. Since the members 6 and 20 and the link member 25 are used, the pressure rollers 5 and 19 can be uniformly pressed against the paper feed rollers 4 and 18 at both ends in the axial direction. Can be prevented.

  Further, since the paper feed mechanism 1 of the present embodiment drives the pressure contact release mechanism P3 before the pressure contact is released when the recording paper passes through the paper feed means P1 and P2, recording during conveyance during printing is performed. Since it is possible to prevent uneven conveyance due to vibrations or the like that occur when the pressure contact with the paper is released, it is possible to improve the recording result.

  In the embodiment of the present invention, the pressure release mechanism P3 is described as being disposed on the second paper feed means P2 side. However, the pressure release mechanism P3 is disposed on the first paper feed means P1 side. May be.

  Further, the first and second elastic members 15 and 21 have been described so that the first and second pressure rollers 5 and 19 are in pressure contact with the first and second paper feed rollers 4 and 18 by using a tension coil spring. The first and second elastic members 15 and 21 may be compression coil springs.

The principal part perspective view which shows one Embodiment of the paper feed mechanism of this invention FIG. 1A is a second control cam side plan view of a second cam member of the pressure release member in the paper feed mechanism of FIG. 1, FIG. 1B is a side view, and FIG. 1C is a first control cam side plan view. The principal part front view of the 2nd state in which the press contact roller is contacting the paper feed roller in both the first paper feed means and the second paper feed means Plan view of FIG. VV sectional view in FIG. The first pressure roller in the first paper feed means is in pressure contact with the first paper feed roller, and the second paper feed means is released from the pressure contact of the second pressure roller with respect to the second paper feed roller. Figure Plan view of FIG. VIII-VIII sectional view in FIG. The first paper feed means releases the pressure contact of the first pressure contact roller to the first paper feed roller, and the second paper feed means requires the second pressure contact roller to be in pressure contact with the second paper feed roller. Front view Plan view of FIG. XI-XI sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feed mechanism 2 Printing means 3 Platen roller 4 1st paper feed roller 5 1st press-contact roller 5a Rotating shaft 6 1st roller support member 6a 1st roller support part 6b Hook part 6c 1st rotation support part 6d Locking part 7 Drive shaft 8 Motor 9 Printer body 10 First cam member 11 Second cam member 12 First control cam 13 Second control cam 15 First elastic member 18 Second paper feed roller 19 Second press roller 19a Rotating shaft 20 Second Roller support member 20a Second roller support portion 20c Second rotation support portion 20d Locking portion 21 Second elastic member 25 Link member 26 Locking hole 27 Link plate 28 Cam hole 29 First roller 30 Second roller P1 First paper Feed means P2 Second paper feed means P3 Pressure release mechanism

Claims (2)

A pair of bell crank-shaped roller support members on the upstream and downstream sides of the printing means in the recording paper conveyance direction at the time of printing swing on the chassis with the pivot support formed at the corner as the swing center. The roller support member is disposed freely, and the lower end portion of the roller support member is elastically urged by the elastic member to the opposite side of the direction in which the printing unit is disposed, so that the pressure contact is supported between the upper end portions of the pair of roller support members. Paper feeding means is provided that enables the roller to be pressed against the paper feeding roller arranged between the chassis,
Between the chassis, either on the upstream side of the paper feeding means arranged on the upstream side in the conveyance direction of the recording paper or on the downstream side of the paper feeding means arranged on the downstream side in the conveyance direction of the recording paper The roller support member in each paper feed means is swung against the urging force of the elastic member by rotating the drive shaft supported by the roller at a predetermined angle by the drive force of the drive source, and the pressure roller of the paper feed roller A paper feed mechanism having a pressure release mechanism for releasing the pressure contact. The pressure release mechanism includes a long link member that connects a first control cam of a bonded cam member that is fixed to both end portions in the axial direction of the drive shaft by rotating the drive shaft by a predetermined angle. The link member is slid along a recording sheet conveyance path by engaging with a first roller formed on a link plate that is erected on one end side of the link member so as to be perpendicular to the drive shaft. Pulling the lower end portion of the roller support member in the other paper feeding means located in the engagement hole formed on the other end side to the printing means side, swinging about the rotation support portion as a fulcrum,
The second control cam of the cam member is engaged with a second roller formed at the lower end portion of the roller support member in one paper feeding means disposed in the vicinity of the drive shaft, and the lower end portion is printed by the printing means. The paper feeding mechanism according to claim 1, wherein the paper feeding mechanism is pressed to the side and swings with the rotation support portion as a fulcrum.

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