JPH107284A - Paper feeding device of printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeding device of a printer high in reliability, productivity and precision. SOLUTION: This device is constituted of a paper feeding roller 1, a pich roller having a groove part on its center, a pinch roller holder 3 having a fulcrum part free to align and a contact part to regulate revolutional quantity and a pinch roller spring 4. Consequently, the pinch roller spring 3 is automatically aligned, it is possible to provide uniform pressure contact of the paper feeding roller 1 and the pinch roller 2, and it is possible to provide a paper feeding device of a printer high in reliability, productivity and precision.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a paper feeder for a printer. More specifically, the present invention relates to a paper feeding device of a printer that presses and holds a recording medium with a paper feed roller and a pinch roller and conveys the recording medium by rotation of the paper feed roller.

[0002]

2. Description of the Related Art Conventionally, in a recording apparatus such as a printer, a recording medium is pressed by a pinch roller using a cylindrical rubber-made elastic paper feeding roller, and the recording medium is pressed against the paper feeding roller. The recording medium is conveyed by the frictional force between the rubber of the paper feed roller and the recording medium. However, in recent years, with the increase in resolution of printers, the output of image information, and the spread of DTP (desktop publishing), there has been a demand for higher precision in the paper feed amount of a recording medium.

When the paper feed roller is made of rubber elastic material, it is difficult to obtain the outer diameter accuracy due to the deformation of the rubber during processing, the outer dimensions change greatly with temperature, and the paper is deformed by the pressure of the pinch roller. There are many factors that cause the outer diameter to be deformed, for example, and the required paper feeding accuracy is difficult to obtain. Therefore, for example, Japanese Patent Application Laid-Open
No. 14,157, a paper feed roller formed by blasting a surface of aluminum or the like;
A paper feed roller sprayed with ceramics on the surface of a rigid cylindrical member as disclosed in Japanese Patent Application No. 0-258050;
Also, as disclosed in Japanese Patent Application Laid-Open No. 2-169432, a paper feed roller coated with a thin film of an elastic material has been proposed.

In each of these paper feed rollers, since the cylindrical member is formed of a rigid member, deformation during processing is small, the outer diameter does not change much with temperature, and the cylindrical member has high rigidity. Therefore, it is possible to provide a high-precision paper feeder without being deformed by the pressure of the pinch roller. FIG. 6 shows the configuration of the conventional example described above.
This will be described in more detail with reference to FIG.

FIG. 6 is a cross-sectional view of a conventional example, and FIG.
Is a plan view of the conventional example. 101 has high rigidity,
A paper feed roller having a high friction coefficient;
1 is a pinch roller provided opposite to the pinch roller 1. A paper feed gear (not shown) is coaxially connected to one end of the paper feed roller 101.
Are connected to a paper feed motor as a driving source by a train (not shown). Pinch roller 102
Are rotatably held by a pinch roller holder 103.

The pinch roller holder 103 is rotatably held by a frame 104 on a rotating shaft 120. Also,
The other end of the holding portion of the pinch roller 102 of the pinch roller holder 103 has a pinch roller spring 105 serving as an urging member.
There is a hook for hanging. One end of the pinch roller spring 105 is hung on the pinch roller holder 103 and the other end is hung on the frame 104.
The lever is configured so as to be pressed to 1.

[0007] The force of the pinch roller spring 105 is transmitted to the pinch roller 102 via the pinch roller holder 103. The recording paper 106 as a recording medium is a pinch roller 1
02, and the pinch roller 1
02 is pressed by the paper feed roller 101. When the paper feed motor is rotated in this state, the wheel train and the paper feed gear rotate sequentially, and the paper feed roller 101 fixed to the paper feed gear also rotates. The recording paper 106 is
1, the paper is fed by the frictional force between the paper feed roller 101 and the recording paper 107.

[0008] The reason why the pinch roller 102 rotates is to reduce the load on the pinch roller 102. 111
Is a paper guide that guides the upper surface of the recording paper 106;
Is a paper guide below the lower surface of the recording paper 106,
The recording paper 106 passes between the upper paper guide 111 and the lower paper guide 112 while being guided.

[0009]

However, the prior art configured as described above has the following problems.

FIG. 8 shows a conventional paper feed roller 101,
FIG. 3 is a top view showing a contact state of a pinch roller 102. The parallelism between the paper feed roller 101 and the pinch roller 102 is
It is determined by the parallelism of the axis BA of the paper feed roller 101 and the axis BC of the rotating shaft 120, and the parallelism of the axis BC of the rotating shaft 120 and the axis BB of the pinch roller 102. Conventionally, when the paper feed roller 101 made of a rubber elastic material is used, even when the parallelism between the paper feed roller 101 and the pinch roller 102 is deviated, the paper feed roller 101 and the pinch roller 102 are deformed by the rubber elastic material. It was possible to hit evenly.

However, when a highly rigid paper feed roller is used in order to improve the paper feed accuracy, if the parallelism is deviated, the paper feed roller 101 and the pinch roller 102 only partially contact. When contact is only partially made like this,
It may cause skewing, wrinkling and tearing of the recording paper,
It may cause abnormal wear of the pinch roller and paper feed roller,
The paper feeding accuracy is reduced, and the reliability is reduced.

Further, in the configuration of the conventional example, in order to maintain the parallelism between the axis of the paper feed roller and the axis of the pinch roller, it is necessary to increase the accuracy of each component. Not realistic. Further, a method of adjusting the parallelism of the axis can be considered, but it is not desirable because the productivity is reduced due to an increase in the number of parts, addition of an adjustment step, confirmation, and the like. Further, since the rotating shaft 102 is fixed through the hole of the frame 104 and the hole of the pinch roller holder 103, many assembling steps are required, the assembling time is lengthened, and the productivity is poor.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and the paper feed is highly accurate and highly reliable.
Another object of the present invention is to provide a paper feeder for a printer which can be easily assembled and has excellent productivity.

[0014]

In order to solve the above-mentioned problems, a paper feeder of a printer according to the present invention comprises a paper feed roller driven to rotate, a pinch roller pressing the paper feed roller, and a pinch roller. A pinch roller holder rotatably held and biasing means for pressing the pinch roller against the paper feed roller via the pinch roller holder are provided, and the recording medium is held between the paper feed roller and the pinch roller. A paper feeder of a printer for conveying a paper is characterized in that the paper feeder has a centering means for centering the paper feed roller and the pinch roller so that the rotation center axes thereof are substantially parallel.

According to the above configuration, the centering means aligns the rotation center axes of the paper feed roller and the pinch roller in parallel.
Since the recording medium is conveyed while being pressed uniformly, it is possible to provide a paper feed mechanism with improved conveyance quality that has good straightness and does not generate skew, wrinkles or tears of the recording paper. Further, abnormal wear of the pinch roller and the paper feed roller does not occur.

The centering means includes: a pinch roller having pinch rollers disposed at both ends and having pressure contact portions for pressing the paper feed roller; and a rotation fulcrum portion rotatable in the transport direction of the recording medium. Has a pinch roller holder arranged in a transport area between the press contact portions.

According to the above configuration, the pinch roller holder has the pressing portions for pressing the paper feed roller pressed on both sides of the rotation fulcrum portion. Until the pinch roller holder is removed, the pinch roller holder is rotated and aligned so as to obtain uniform contact.

Further, the pinch roller holder is formed between a supporting portion for supporting the pinch roller and an engaging portion with which the urging member is engaged. A fulcrum is provided.

In this case, since the rotation fulcrum for engaging with the support is in the form of an open groove, the pinch roller holder is aligned with the support, and the pinch roller holder can be easily attached to the support. This has the effect of improving productivity.

Further, the pinch roller holder is characterized in that a regulating member for regulating the rotation of the paper feed roller in the axial direction to a predetermined amount or less is arranged.

In this case, since the position of the pinch roller holder is stable, the positioning can be easily performed, and the assembling property can be improved, and alignment failure due to an assembling error does not occur, and the reliability is improved. effective.

Further, the paper feeding mechanism of the printer includes a paper guide member that forms a conveyance path of the recording medium that is disposed with a gap from the pinch holder on a side opposite to the side where the groove of the pinch holder is disposed. And the groove of the pinch holder is
It is characterized by being deeper than the gap.

In this case, even if an external force is applied to move the pinch holder away from the support member, the movement is restricted by contacting the paper guide member. However, since the movement amount is smaller than the groove depth, the pinch holder and the support member are not supported. Since the member is held at a fixed position without being disengaged from the member, there is an effect that a highly reliable paper feeder for a printer which is resistant to vibration and impact can be provided.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail using an embodiment of the present invention. FIG. 1 is a perspective view of a printer according to an embodiment of the paper feeder of the printer according to the present invention, FIG. 2 is a top view of the paper feeder, FIG. 3 is a cross-sectional view of the paper feeder, and FIG. It is a front view of a part. Hereinafter, description will be made based on the drawings.

1 is a paper feed roller, 2 is a pinch roller, 3
Denotes a pinch roller holder, 4 denotes a frame, 5 denotes a pinch roller spring, and 6 denotes a recording sheet.

The paper feed roller 1 is formed by plasma-spraying a ceramic such as alumina or titania on a metal sleeve. Stainless steel, brass,
Aluminum or the like is used. The surface roughness of the outer periphery of the sprayed metal sleeve is from Rmax30 μm to Rmax1.
It has a surface roughness of about 00 μm, and the recording paper can be fed by unevenness on the surface of the recording paper. By spraying the ceramic, a highly durable paper feed roller can be obtained. Further, since the sleeve is made of metal, deformation during the processing can be suppressed, and high external precision can be obtained. In addition, because it is made of metal sleeve,
Since there is no deformation due to the pressure of the pinch roller 2 and no deformation due to the load of the recording paper, it is possible to feed the paper with high accuracy according to the rotation angle of the paper feed roller 1. The paper feed roller 1 sprayed with ceramic is fixed to a paper feed shaft 7. As a fixing method, bonding, press-fitting, or the like is preferable because of high reliability. Another possible method is to cut the metal shaft and create a paper feed roller, followed by thermal spraying.However, the cutting time is longer and productivity is poor, and masking is required to prevent thermal spraying on the rotary bearing. This is inferior in productivity, and furthermore, a high temperature is applied during thermal spraying. Therefore, in the case of a large member, there is a problem that distortion due to heat is caused and deterioration of accuracy is caused. There are also a method of forming a film having a high coefficient of friction by painting or the like, and a method of performing blast treatment.

The paper feed roller shaft 7 thus configured is rotatably supported at both ends, and has a paper feed gear 8 fixed at one end. The paper feed gear 8 is connected to a paper feed motor 10 via a train wheel 9,
, The paper feed roller 1 also rotates. The speed from the paper feed motor 10 to the paper feed gear 8 is reduced as necessary. By controlling the rotation angle of the paper feed motor 10, the rotation angle of the paper feed gear 8, ie, the paper feed roller 1, can be controlled. It is configured as follows. The paper feed motor 10 uses a stepping motor to appropriately control the paper feed amount.

Next, the pinch roller 2 has a cylindrical pressing portion 2a for pressing the paper feed roller 1 through the recording paper.
A groove 2b located at the center of the pressing portion 2a and having a smaller diameter than the pressing portion 2a; and a pressing portion 2a located on both sides of the pressing portion 2a.
And a rotating shaft portion 2c having a small outer diameter and a coaxial shape, and has a left-right symmetric shape.

The pinch roller holder 3 hangs the pinch roller holding portion 3e and the pinch roller spring 3 to form a hook portion 3a serving as a leverage point, a fulcrum portion 3b supported by the frame 4 and serving as a leverage fulcrum, and a fulcrum portion 3b. Abutment portions 3d located on both sides of the abutment portion to abut against the frame 4 to restrict rotation in the left-right direction;
The pinch roller 3 is provided on the opposite side of the hook portion 3 a with respect to the contact portion 3 d, and is also a lever action point, and further includes a pinch roller holding portion 3 e for holding the pinch roller 2.

As shown in the cross-sectional view of FIG. 3, the pinch roller holder 3 has a groove radially extending from the contact portion of the frame 4 so that the pinch roller holder 3 can rotate in the direction of arrow C with the fulcrum 3b as a fulcrum. It is formed to be wide. As shown in the front view of FIG. 4, the fulcrum 3b has a mountain shape with respect to the end face of the frame 4, and rotates in the left-right direction which is the axial direction of the paper feed roller 1 in the direction of arrow A. It is movable.

Further, as shown in the top view of FIG. 2, the fulcrum 3b is formed such that the groove is formed to have a substantially plate thickness at the center and wider than the frame 4 at both sides thereof. The paper feed roller 1 is also configured to be rotatable in the circumferential direction of the paper feed roller 1 in the direction of arrow B. The contact portions 3d are set at both ends with a predetermined gap from the end surface of the frame 4 so as not to hinder the rotation of the pinch roller 3 in the axial direction (the direction of the arrow A) of the paper feed roller 1, Further, the sheet feed roller 1 is formed wider than the plate thickness so as not to hinder the rotation of the sheet feed roller 1 in the circumferential direction (the direction of arrow B).

The position of the contact portion 3d, the chevron shape and the radial shape of the fulcrum 3b are determined by the parallelism of the axis of the paper feed roller 1 and the axis of the pinch roller 2. The fulcrum portion 3b and the hook portion 3a are provided at a position that is the center of the pinch roller holder 3 with respect to the axial direction of the paper feed roller 1.
Further, the pinch roller holding portion 3e for rotatably holding the rotation shaft portion 2c of the pinch roller 2 is provided symmetrically with respect to an extension of a line connecting the fulcrum portion 3b in contact with the hook portion 3a.

The two pinch roller holding portions 3e and the rotating shaft portion 2c are shaped to be snap-fitted. The pinch roller 2 can rotate the rotating shaft portions 2c provided on both sides of the pinch roller 2. And is normally held without coming off. Since the fulcrum 3b and the abutment 3d of the pinch roller holder 2 are open on the frame 4, the fulcrum 3b and the abutment 3d can be easily attached to the support 4b of the frame 4 during assembly. Also, two contact portions 3d and a fulcrum portion 3
Positioning can be easily performed only by aligning the groove b with the frame 4, and there is no erroneous assembly.

If the abutting portion 3d is not provided, the pinch roller 2 may be attached to the paper feed roller 1 in a circumferential direction, which is inconvenient unless a moment of the pinch roller 2 is generated. However, in the present embodiment, since the contact portion 3d is provided on the pinch roller holder 3, the pinch roller holder 2 can be easily positioned, and erroneous assembly can be prevented.

The frame 4 holds a carriage motor 13 for driving a carriage 16 on which a print head (not shown) is mounted, and also applies tension to the drive belt 17 to be a turning point on one side of the endless track. Driven pulley 1
Further, an end surface 4b for receiving the fulcrum 3b of the pinch roller holder 3 and a hook 4a for holding the pinch roller spring 5 on the side opposite to the pinch roller holder 3 are provided.

A support 4b for receiving the fulcrum 3b of the pinch roller holder 3 is formed on the end face of the frame 4,
It has a concave shape. The width of the concave shape of the support portion 4b is substantially equal to the width of the fulcrum portion 3b of the pinch roller holder 3, and
The pinch roller holder 3 is formed so as to have a slight gap so as not to hinder the rotation of the pinch roller holder 3 due to the centering, and to mount the pinch roller holder 3 at a predetermined position so that the position does not shift. The hook portion 4a is provided in a plane perpendicular to the axial direction of the paper feed roller 1 and the pinch roller 2 and passing through the center of the axis.

The pinch roller spring 5 is a tension coil spring, which pulls the hook 3a of the pinch roller holder 3 toward the hook 4a of the frame 4 and urges the pinch roller 2 to the paper feed roller 1 via the recording paper 6. I do. As described above, the hook portion 4a of the frame 4 is provided in a plane perpendicular to the axial direction of the paper feed roller 1 and the pinch roller 2 and passing through the center of the axis, and the hook portion 3a of the pinch roller holder 3 is provided. Are also in the same plane. For this reason, the pinch roller spring 5 can uniformly urge the pinch roller 2 in the axial direction.

In order to uniformly urge the pinch roller 2 against the paper feed roller 1, in addition to the above-described method, a plurality of paper feed rollers 1, symmetrically with respect to a plane perpendicular to the axis of the pinch roller 2 and passing through the center. It is possible to provide a pair of the pinch roller spring 5, the hook portion 4a of the frame 4, and the hook portion 3a of the pinch roller holder 3, but the number of parts increases, and the spring force of the left and right pinch roller springs 5 varies. Since there is an adverse effect, the pinch roller spring 5, the hook portion 4 a of the frame 4, and the hook of the pinch roller holder 3 are provided on a surface perpendicular to the axes of the paper feed roller 1 and the pinch roller 2 and passing through the center as in the present embodiment. It is desirable to provide the part 3a.

In this embodiment, the paper feed roller 1, the pinch roller 2, the pinch roller holder 3,
Pinch roller spring 5 and hook 4b of frame 4
In the plane direction of the recording paper 6
I am equipped with a pair. In order to avoid the skew of the recording paper 6, it is desirable to install the recording paper 6 so that a paper feeding force is evenly applied to the recording paper 6. If the purpose is achieved, the above-mentioned paper feeding roller 1, pinch roller 2 , The pinch roller holder 3, the pinch roller spring 5, and the paper feed portion constituted by the hook portion 4 b of the frame 4 may be one set, or may be three or more sets.

Numeral 11 denotes an upper paper guide for guiding the upper surface of the recording paper 6, and 12 denotes a lower paper guide for guiding the lower surface of the recording paper 6. When the recording paper 6 is inserted, the paper feed roller 1 and the pinch roller 2 To the print head (not shown),
It is provided to reliably guide to the discharge position.

As an assembling procedure, the paper feed roller 1 and the paper feed shaft 7 incorporating the paper feed gear 8 are assembled in the printer, and then the paper guide lower 12 and the paper guide upper 11 are assembled in the printer in this order. The pinch roller 2 is incorporated in the pinch roller holder 3. Next, the supporting portion 4b of the frame 4
The fulcrum 3b of the pinch roller 3 is aligned, and the abutment 3
Position the frame 4 as if it were sandwiched by d. Next, the pinch roller spring 5 is hooked on the hook 3a of the pinch roller holder 3 and the hook 4b of the frame 4.

The pinch roller holder 3 is pulled upward so that the fulcrum 3b and the frame 4b engage with each other. However, since the fulcrum has a deep groove shape, the pinch roller holder 3 does not rotate more than a predetermined amount.
In the normal state, the frame 4 is held without coming off.
In this manner, the fulcrum portion of the pinch roller holder 3 and the contact portion 3d
Can be easily assembled because it is opened upward.

Next, the frame 4 on which the pinch roller holder 3 is assembled is assembled from above the paper guide 12.
At this time, the gap between the lower surface 3c of the pinch roller holder 3 and the paper guide 11 is set smaller than the groove height of the fulcrum 3b of the pinch roller holder 3 so that the pinch roller holder 3 can rotate. After the frame 4 is installed in the printer, the fulcrum 3b of the pinch roller holder 3
It does not come off from the support portion 4b of the frame 4, and even if a downward force is applied to the pinch roller holder 3, the paper guide upper 11 functions as a stopper and the pinch roller holder 3 does not drop out, so that reliability is improved. improves.

When the paper feeder thus constructed is assembled with the axis AA of the paper feed roller 1 and the axis AB of the pinch roller 2 shifted as shown in FIG. 5, one side of the pressing portion 2a of the pinch roller 2 Only the paper feed roller 1 comes into pressure contact with the paper feed roller 1. That is, only the lower pressing portion 2a in the figure comes into pressure contact with the paper feed roller 1, and the pressing portion 2a of the pinch roller 2 cannot urge the paper feed roller 1 with a uniform force.

When the paper feed roller 1 rotates from this state, a force in the direction of the arrow D is applied to the pressing portion 2a of the pinch roller 2 which has a partial contact. Since the force in the direction of the arrow D is deflected and acts on the fulcrum 3b of the pinch roller holder 3,
A moment in the direction of arrow E is generated about the fulcrum 3b. Since the fulcrum 3b of the pinch roller holder 3 is configured to be rotatable, the moment in the direction of the arrow E causes the pinch roller holder 3 to move about the fulcrum 3b around the fulcrum 3b.
Rotate in the direction.

When the opposite pressing portion 3a is pressed against the paper feed roller 1 and the moment about the fulcrum 3b is balanced, that is, when the forces applied to the two pressing portions 2a are equalized. The rotation stops at. Further, since the pinch roller 2 has a symmetrical shape in the axial direction, the pinch roller 2 can be uniformly pressed against the paper feed roller 1.

As described above, the axis AA of the pinch roller 1 is
Even if the axis AB of the pinch roller 3 is not parallel, the paper feed roller 1 is rotated, and the center is automatically aligned.
It is possible to obtain a uniform feed force. Naturally, when the deviation of the axis is opposite to that in FIG.
Following the reverse of the above operation, the two pressing portions 2a of the pinch roller 2 are pressed against the paper feed roller 1 with an equal force.

The pressing portion 2 is located at the center of the pinch roller 2.
The reason why the groove 2b having a smaller diameter than a is provided is to increase the moment for centering, and the centering can be similarly performed without the groove 2b. However, since there is a limitation on the cylindricity of the pressing portion 2a in manufacturing parts, it is desirable to provide the groove portion 2b also in order to prevent occurrence of one-side contact. Naturally, the groove 2b only needs to be smaller than the outer diameter of the pressing portion 2a, and need not be circular.

Next, the configuration of the printing mechanism will be described. A carriage 16 having a print head (not shown) is mounted on a guide shaft 18 provided in parallel with the paper feed shaft 1.
Is mounted so as to be slidable in the axial direction. The carriage motor 13 attached to the frame 4 includes:
The drive pulley 17 is coaxially fixed. On the opposite side of the drive pulley 14 with respect to the sliding direction of the carriage 14,
There is a driven pulley 15, and the driving pulley 14 and the driven pulley 15 are provided with a driving belt 17 having a predetermined tension.
Is wrapped around. Drive belt 14 on carriage 16
The carriage 16 reciprocates along the guide shaft 18 by rotating the carriage motor 13 forward and backward. As the drive belt 17, a toothed belt is usually used so that slippage does not occur with the drive pulley 14. Further, the carriage motor 13 is
In order to control the position, that is, control the printing position, a step motor, a servo motor with an encoder, or the like is used. When the carriage 16 is moving, printing is performed in synchronism with the phase switching timing in the case of a stepping motor, or in synchronism with the output signal of an encoder in the case of a servomotor with an encoder. (Not shown). Carriage 1
6, the print head is driven, and then the paper feed motor 10 is rotated to feed the recording paper 6 pressed and held by the paper feed roller 1 and the pinch roller 2, and the recording is repeated by this repetition. Printing is performed on the paper 6, and documents, images, and the like are recorded. In this embodiment, a so-called serial printer that moves and prints the print head has been described. However, a similar effect can be obtained by performing the printing with a so-called line printer that fixes and prints the print head.

[0050]

As described above, the paper feeder of the printer according to the present invention comprises a paper feed roller which is driven to rotate, a pinch roller which presses the paper feed roller, and a pinch which rotatably holds the pinch roller. A paper feeder for a printer, comprising: a roller holder; and biasing means for pressing the pinch roller against the paper feed roller via the pinch roller holder. The printer feeds the recording medium while nipping and transporting the recording medium between the paper feed roller and the pinch roller. The apparatus has alignment means for aligning the paper feed roller and the pinch roller so that the rotation center axes thereof are substantially parallel, so that the recording medium is uniformly pressed and conveyed, so that the linearity is improved. Often, it is possible to provide a paper feeding mechanism with improved conveyance quality that does not cause skewing or wrinkling or tearing of the recording paper. Further, abnormal wear of the pinch roller and the paper feed roller does not occur.

The centering means includes a pinch roller having pinch rollers disposed at both ends and having pressure contact portions for pressing the paper feed roller, and a rotation fulcrum portion which is rotatable in the conveying direction of the recording medium. Has a pinch roller holder arranged in the transport area between the pressure contact portions, the pinch roller holder has pressure contact portions for pressing the paper feed roller against each other, which are disposed on both sides of the rotation fulcrum portion. The moments generated by the paper feed are opposite to each other, and the pinch roller holder is rotated and aligned so as to obtain uniform contact until the moment is balanced.

Further, the pinch roller holder is formed between a supporting portion for supporting the pinch roller and an engaging portion with which the urging member is engaged. Since the fulcrum portion is provided, the pinch roller holder is aligned with the support portion, and the pinch roller holder can be easily attached to the support portion, thereby improving the productivity.

Further, since the pinch roller holder is provided with a restricting member for restricting the rotation of the paper feed roller in the axial direction to a predetermined amount or less, the position of the pinch roller holder is stabilized. The positioning can be easily performed, the assembling property can be improved, and alignment failure due to an assembling error does not occur, so that the reliability is improved.

Further, the paper feeding mechanism of the printer includes a paper guide member that forms a conveyance path for a recording medium that is disposed with a gap from the pinch holder on a side opposite to the side where the groove of the pinch holder is disposed. And the groove of the pinch holder is
Even if an external force acts to move the pinch holder away from the support member, the movement is restricted by contacting the paper guide member, but the amount of movement is smaller than the groove depth. Since the member is held at a fixed position without being disengaged from the member, there is an effect that a highly reliable paper feeder for a printer which is resistant to vibration and impact can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a top view of one embodiment of the present invention.

FIG. 3 is a cross-sectional view of one embodiment of the present invention.

FIG. 4 is a front view of one embodiment of the present invention.

FIG. 5 is a top view showing the operation of the embodiment of the present invention.

FIG. 6 is a sectional view showing a conventional example.

FIG. 7 is a top view of a conventional example.

FIG. 8 is a top view showing the operation of the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper feed roller 2 Pinch roller 2a Press part 2b Groove part 3 Pinch roller holder 3a Hook part 3b Support point 3c Lower surface part 3d Contact part 4 Frame 4a Hook part 4b Support part 5 Pinch roller spring 6 Recording paper

Claims (5)

[Claims] 1. A paper feed roller driven to rotate, a pinch roller pressing the paper feed roller, a pinch roller holder rotatably holding the pinch roller, and the pinch roller via the pinch roller holder. A paper feeder for a printer, comprising: urging means for pressing the paper feed roller, wherein the recording medium is conveyed while being held between the paper feed roller and the pinch roller. The paper feed roller and the pinch roller A paper feeding device for a printer, comprising a centering means for performing centering so that the rotation center axes are substantially parallel to each other. 2. The alignment means, wherein the pinch roller is
The pinch roller, which is disposed at both ends and has pressure contact portions for pressing the paper feed roller, and a rotation fulcrum portion which is rotatable in the transport direction of the recording medium are disposed in a transport area between the pressure contact portions. The paper feeding device for a printer according to claim 1, further comprising the pinch roller holder provided. 3. The pinch roller holder is formed between a support portion that supports the pinch roller and an engagement portion with which the urging member engages, and has a groove shape with one opening engaged with the support portion. 3. The paper feeding device for a printer according to claim 1, further comprising the rotation fulcrum. 4. The pinch roller holder according to claim 1, further comprising a regulating member for regulating the rotation of the paper feed roller in the axial direction to a predetermined amount or less. Printer paper feeder. 5. The paper feed mechanism of a printer according to claim 3, wherein the pinch holder is provided with a gap between the pinch holder and the recording medium on a side opposite to a side where the groove is disposed. The paper feeding device for a printer according to claim 3, further comprising a paper guide member that forms the groove, wherein the groove of the pinch holder is deeper than the gap.