JP3869879B2 - Paper feeder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper feeding device provided in an image forming apparatus such as a personal use small printer.
[0002]
[Prior art]
With the trend of downsizing computers in recent years, individuals often use personal computers (personal computers) and workstations on their desks. Along with this trend, there is a demand for a small printer that can be placed on a personal desk so that documents and tables created on a personal computer can be easily printed out.
[0003]
In a small printer, the paper feeding mechanism needs to be small. As a technique related to the present invention for miniaturization, there is a technique described in Japanese Utility Model Publication No. 4-12037. In this publication, a paper feeding mechanism including a separation roller and a conveyance auxiliary roller is proposed. More specifically, a pressing plate biased by a spring is pressed against the separation roller. The auxiliary roller is attached to the plate surface in a non-contact manner. That is, a concave portion is formed on the plate surface, and the auxiliary roller is fitted in the concave portion in a non-contact manner. Thereby, the wear of the peripheral surface of the auxiliary roller is suppressed, and the conveying force is improved by sitting on the paper.
[0004]
[Problems to be solved by the invention]
By the way, there are various types of paper, from thick ones such as envelopes to thin ones such as tracing paper.
However, with the technique disclosed in the above publication, it is difficult to change the gap between the auxiliary roller and the plate surface each time according to the paper. Therefore, there are problems that the tracing paper can be transported but the envelope cannot be transported, and that the clearance is so wide that the transport force by the auxiliary roller is not substantially provided. For this reason, the technology disclosed in the above-mentioned public notice has a problem that it cannot cope with sheets of various thicknesses.
[0005]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a paper feeding device that solves the above technical problems, can suppress wear on the peripheral surface of a roller for assisting paper conveyance, and can also handle paper of various thicknesses. That is.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a paper feeding device for supplying paper to the conveyance path, wherein the paper placement unit for placing the paper and the paper conveyance path are provided. At the center of the rotating shaft provided in the crossing direction, it is rotated with the rotation of the rotating shaft, and the paper to be transported is taken out from the paper placed on the paper placement section, and the paper is transported A separation roller for sending out to the path, and a predetermined friction for preventing a plurality of sheets taken out by the separation roller from being pressed against the separation roller by a first urging force by a separation spring across the conveyance path A separation pad having resistance, and a conveyance roller that is attached to both sides of the separation roller of the rotation shaft and rotates with the rotation of the rotation shaft, and assists the conveyance of the sheet taken out from the sheet placing portion by the separation roller; , Conveyance The friction resistance necessary and sufficient to generate the auxiliary conveyance force by the conveyance roller in a state where the conveyance sheet is pressed against the conveyance roller with the second urging force pressed by the conveyance spring across the conveyance path. Yes And a separate member from the separation pad. A sheet feeding device including a conveyance pad.
[0007]
According to the present invention, a pad having a frictional resistance necessary and sufficient to generate an auxiliary conveying force necessary for assisting paper conveyance is pressed against a roller for assisting paper conveyance. That is, since it is sufficient to generate only the auxiliary conveying force, the frictional resistance of the pad can be set to a very small value. Therefore, even when the paper is out, wear on the peripheral surface of the roller can be suppressed.
[0008]
In addition, since the roller that should generate the auxiliary conveying force is pressed against the pad, the auxiliary conveying force can be reliably provided to the paper regardless of the thickness of the paper.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a perspective view showing a simplified external configuration of a printer according to an embodiment of the present invention, and FIGS. 2 and 3 are views of the printer viewed from the left side in order to explain the internal configuration of the printer. It is. 2 and 3, the configuration relating to the appearance is indicated by a two-dot chain line in order to emphasize the internal configuration of the printer.
[0010]
Below, the outline | summary and external appearance structure of this printer are demonstrated first. This printer is of a so-called personal use that is used by being placed on a desk of each individual. That is, this printer is connected to a personal computer (personal computer) used by each individual, and is used for the purpose of easily printing out documents or tables created by the individual using a personal computer.
[0011]
As shown in FIGS. 1 to 3, the printer includes a main body 1 and a paper feed tray 2. The external appearance of the apparatus main body 1 is constituted by a cover 3 that can be opened and closed, and an upper housing 4 and a lower housing 5 fitted together. The paper feed tray 2 is used for placing paper to be printed, and is removable from the apparatus main body 1.
[0012]
As shown in FIGS. 1 to 3, the cover 3 is attached to the apparatus main body 1 so as to cover the upper front portion of the printer. The cover 3 can be opened in the direction of arrow A from the front side of the printer toward the rear side with the fulcrum portion 6 as the center. FIG. 3 shows a state in which the cover 3 is opened. When the cover 3 is opened, it is preferable to remove the paper feed tray 2.
[0013]
A tray insertion port 7 is formed on the rear side of the cover 3. The paper feed tray 2 can be attached by being inserted into the tray insertion slot 7 and can be removed by being pulled out from the tray insertion slot 7.
A connector 8 is attached to the rear surface portion 4 a of the upper housing 4. The connector 8 is for connecting the printer to a personal computer or the like. That is, the printer cable 9 having one end connected to the personal computer is connected to the connector 8.
[0014]
As can be seen from FIGS. 2 and 3, the connector 8 and the printer cable 9 protrude from the rear surface portion 4 a of the upper housing 4. The protruding length L is determined by the type of connector 8 and the type of printer cable 9 used.
As shown in FIGS. 1 and 2, the paper feed tray 2 has a shape that extends obliquely upward and rearward from the apparatus main body 1 when inserted into the tray insertion slot 7. When the paper feed tray 2 is attached, the upper end 2a of the paper feed tray 2 is of a size that projects a predetermined length from the rear surface 4a of the upper housing 4. Specifically, the projected image 11 of the upper end portion 2 a of the paper feed tray 2 on the printer installation surface 10 protrudes from the rear surface portion 4 a of the upper housing 4 by substantially the same length as the protruding length L of the connector 8 and the printer cable 9. It is the size to do.
[0015]
As described above, the protruding length L varies depending on the type of the connector 8 and the type of the printer cable 9 to be used. Here, the size and shape of the paper feed tray 2 are estimated in consideration of the maximum protruding length. Designed.
As a result, when the rear surface of the printer is installed along the wall, the operator can use the connector 8 and the connector 8 and the upper end 2a of the paper feed tray 2 as a reference and the upper end 2a along the wall. The printer cable 9 does not collide with the wall. Therefore, it is possible to reduce the burden of installation work for the worker and to prevent the connector 8 from being damaged.
[0016]
In addition, the length of the projected image 11 of the upper end 2a on the printer installation surface 10 protruding from the rear surface 4a of the upper housing 4 is substantially the same as the protruding length L of the connector 8 and the printer cable 9. Therefore, it is possible to meet the demand for narrowing the installation space.
Next, the internal configuration of this printer will be described in detail with reference mainly to FIG. 2 and FIG.
[0017]
As shown in FIGS. 2 and 3, the printer includes a paper feeding unit 20, a laser light irradiation unit 30, an imaging unit 40, a developing unit 50, a transfer unit 60, and a fixing unit 70. A discharge port 80 is formed on the front surface of the printer. The discharge port 80 is formed near the boundary between the upper housing 4 and the lower housing 5.
[0018]
The sheet placed on the sheet feeding tray 2 is conveyed in the order of the sheet feeding unit 20, the imaging unit 40, the transfer unit 60, and the fixing unit 70 along a conveyance path 90 indicated by a broken line formed in the apparatus main body 1. Finally, it is discharged from the discharge port 80 to the outside of the apparatus. As shown in FIG. 2, the transport path 90 is formed in a substantially linear shape with a downward slope from the paper feed tray 2 toward the discharge port 80. This is because the shape is optimal for reducing the size of the printer.
[0019]
The paper feed unit 20 is for sending out the paper placed on the paper feed tray 2 to the transport path 90 formed in the apparatus main body 1. The paper feeding unit 20 is attached to the cover 3 and is lifted together with the cover 3 when the cover 3 is opened.
The paper supply unit 20 includes a paper supply roller 21 (this paper supply roller 21 includes a separation roller and a conveyance roller, as will be described later). The paper feed roller 21 is provided at a position where the paper feed tray 2 comes into contact with the surface of the paper feed tray 2 when the paper feed tray 2 is inserted into the tray insertion slot 7.
[0020]
The paper feed unit 20 is also provided with a paper detection switch 22. The paper detection switch 22 is used to detect the presence or absence of paper in order to perform paper feed control, and is provided immediately downstream of the separation roller 21 in the transport path 90. Paper feed control is performed as follows.
That is, when the start of paper feeding is instructed while the paper is placed on the paper feeding tray 2, the rotation of the paper feeding roller 21 is started. As a result, the paper is taken out by the paper feed roller 21 and sent to the transport path 90. The paper reaches the paper detection switch 22 after a predetermined first time has elapsed from the start of rotation of the paper feed roller 21. That is, the paper detection switch 22 is turned on.
[0021]
The rotation of the paper feed roller 21 is stopped after a predetermined second time has elapsed since the paper detection switch 22 was turned on. The second time is set to a time sufficient for the supplied paper to reach the fixing unit 70. The paper that has reached the fixing unit 70 is conveyed by the fixing unit 70 and discharged. When it is necessary to supply the next sheet, the sheet feeding roller 21 is rotated again after a predetermined time has elapsed since the rotation stopped.
[0022]
If the paper detection switch 22 is not turned on even after the first time has elapsed from the start of the rotation of the paper supply roller 21, it is recognized that the paper has run out.
The laser beam irradiation unit 30 is for outputting a laser beam corresponding to an image signal. The laser light irradiation unit 30 is provided in the lower housing 5 of the apparatus main body 1.
[0023]
The laser light irradiation unit 30 includes a laser light source 31 and an optical system 32. The laser light source 31 is composed of a semiconductor laser or the like. The optical system 32 includes a plurality of reflecting mirrors, lenses, polygon mirrors, and the like. Laser light generated by the laser light source 31 is irradiated toward the imaging unit 40 via the optical system 32.
[0024]
The laser beam irradiation unit 30 is electrically connected to the connector 8. The laser light irradiation unit 30 determines the irradiation light amount of the laser light based on image data given from the personal computer via the printer cable 9 and the connector 8. Then, the laser light is generated from the laser light source 31 based on the determined irradiation light amount of the laser light.
[0025]
The imaging unit 40, the developing unit 50, and the transfer unit 60 are for forming an image on the paper supplied from the paper supply unit 20.
The imaging unit 40 includes a photoconductor 41 that is exposed by the laser beam described above. A charging charger 42 and a paper dust collecting brush 43 are provided along the periphery of the photoreceptor 41. As the photosensitive member 41, for example, a small one having a diameter of 16 (mm) is used to reduce the size of the printer.
[0026]
The photoconductor 41 rotates at a constant speed along the arrow B direction during image formation. The surface of the photoconductor 41 is uniformly charged to a predetermined high potential by the charging charger 42 and then exposed to the laser beam from the laser beam irradiation unit 30. In the exposed area that has received light, the charge in that portion escapes to a low potential. As a result, an electrostatic latent image composed of a high potential region and a low potential region is formed on the surface of the photoreceptor 41.
[0027]
When the photosensitive member 41 further rotates and the electrostatic latent image reaches the developing unit 50, the electrostatic latent image is developed into a toner image by the developing unit 50.
The developing unit 50 is provided in the upper housing 4 and includes a toner hopper 51, a sub roller 52, and a developing roller 53. The toner hopper 51 is for filling toner.
[0028]
The sub roller 52 and the developing roller 53 are rotated in the same direction. By this rotation, the toner filled in the toner hopper 51 is frictionally charged, and the toner is electrostatically adsorbed on the peripheral surface thereof. The sub roller 52 is provided in order to more effectively frictionally charge the toner.
A predetermined bias voltage is applied to the sub roller 52 and the developing roller 53. As a result, the toner adhering to the peripheral surface of the developing roller 53 is electrostatically adsorbed only to the exposure area on the surface of the photoreceptor 41. So-called reversal development is performed. As a result, a toner image corresponding to the electrostatic latent image is formed on the surface of the photoreceptor 41.
[0029]
When the photosensitive member 41 further rotates and the toner image reaches the transfer unit 60, the toner image is transferred to the paper conveyed along the conveyance path 90. In other words, the transfer unit 60 includes a transfer roller 61 therein. The leading edge of the paper is supplied between the photoreceptor 41 and the transfer roller 61 in accordance with the leading edge of the toner image facing the transfer roller 61. As a result, the toner images formed on the photoconductor 41 are sequentially transferred onto the paper.
[0030]
The transfer unit 60 is attached to the cover 3 and is lifted together with the cover 3 when the cover 3 is opened.
The toner that has not been transferred to the paper remains on the surface of the photoreceptor 41 after the transfer. Further, when the sheet comes into contact with the surface of the photoreceptor 41, paper dust or the like generated from the sheet is adhered to the surface of the photoreceptor 41 together with the residual toner.
[0031]
The paper dust adhering to the photoconductor 41 is collected by adhering to the tip of the paper dust collection brush 43 when passing through the paper dust collection brush 43 in the imaging unit 40. Further, the residual toner adhesion area of the photoconductor 41 is scattered when the residual toner is disturbed at the tip of the paper dust collection brush 43 when passing through the paper dust collection brush 43. The electrostatic coupling is weakened. The residual toner whose electrostatic coupling is weakened is collected by the developing roller 53 during the next image formation.
[0032]
The transferred paper is supplied to the fixing unit 70. The fixing unit 70 is for fixing the image transferred onto the paper, and is provided between the upper housing 4 and the lower housing 5 along the conveyance path 90.
The fixing unit 70 is divided into an upper fixing unit 71 and a lower fixing unit 72. The lower fixing unit 72 is fixed to the lower housing 5. The upper fixing unit 71 is attached to the lower fixing unit 72 by a fulcrum 73 so as to be rotatable in the direction of arrow C.
[0033]
A space between the upper fixing unit 71 and the lower fixing unit 72 forms a part of the conveyance path 90, and is formed in a substantially straight line with a downward slope from the paper feed tray 2 toward the discharge port 80 as described above. Yes. Both units 71 and 72 are provided with an upper fixing roller 74 and a lower fixing roller 75, respectively. Inside the lower fixing roller 75, a heater (not shown) is provided along its axis.
[0034]
When the cover 3 is closed, the fixing unit 70 is in a closed state as shown in FIG. Specifically, the upper fixing unit 71 is pressed by a pressing portion 3 a protruding from the inside of the cover 3. Here, the upper fixing roller 74 is attached to the upper fixing unit 71 so as to be displaceable in a direction orthogonal to the axial length direction thereof. And it is always elastically biased by a spring or the like in the direction opposite to the arrow C direction. As a result, the upper fixing roller 74 is pressed against the lower fixing roller 75 and is pressed with a predetermined pressure.
[0035]
The cover 3 is closed during image formation. The upper fixing roller 74 is rotated in the direction of arrow D, and the lower fixing roller 75 is rotated in the direction of arrow E. On the other hand, the transferred paper is supplied between the upper fixing roller 74 and the lower fixing roller 75 in the pressed state. At this time, the lower fixing roller 75 is heated by the heat of the heater. As a result, the toner image is melted and fixed on the paper by pressurization and heating.
[0036]
The pressure contact state of the fixing unit 70 is released when the cover 3 is opened as shown in FIG. That is, when the cover 3 is opened, the pressure contact state of the rollers 74 and 75 is released to facilitate the removal of jammed paper. At this time, the rotation of the upper fixing unit 71 is restricted by the front surface portion 4 b of the upper housing 4.
The fixing unit 70 is also provided with an upper discharge roller 76 and a lower discharge roller 77. More specifically, the upper discharge roller 76 is attached to the upper fixing unit 71 and is rotated in the direction of arrow F (see FIG. 2). The lower discharge roller 77 is attached to the lower fixing unit 72, and is rotated in the direction of arrow G (see FIG. 2). By the rotation of the discharge rollers 76 and 77, the fixed sheet is guided to the discharge port 80 and discharged outside the apparatus.
[0037]
Next, a configuration related to sheet feeding will be described in more detail with reference to FIGS.
FIG. 4 is a diagram for explaining the configuration of the paper feed tray 2 and the paper feed roller 21 provided in the paper feed unit 20.
The paper feed roller 21 provided in the paper feed unit 20 includes a separation roller 23 attached to substantially the center of one rotating shaft 26, and two transport rollers 24, 25 attached to both sides of the separation roller 23. It is included. The axial lengths of the separation roller 23 and the transport rollers 24 and 25 are all the same.
[0038]
The separation roller 23 is for taking out a sheet to be transported from the sheets placed on the sheet feeding tray 2. The transport rollers 24 and 25 are for providing an auxiliary transport force to the paper taken out by the separation roller 23 and realizing a smooth paper supply to the transport path 90. That is, since the sheet feeding force of the separating roller 23 is insufficient, the conveying rollers 24 and 25 assist this.
[0039]
The sheet feeding tray 2 includes a bottom surface portion 100, a back surface portion 101 extending obliquely rearward with respect to the bottom surface portion 100, and guide portions 102 formed on both sides of the back surface portion 101. The sheet 103 is placed along the bottom surface portion 100 and the back surface portion 101 as indicated by a two-dot chain line. When the paper feed tray 2 is inserted into the tray insertion slot 7 and is fed, the paper 103 is guided along the guide unit 102.
[0040]
A separation pressure plate 104 is attached to the center of the tip of the bottom surface 100. The separation pressure plate 104 is attached at a position where it comes into contact with the separation roller 23 when the paper feed tray 2 is inserted into the tray insertion port 7. The separation pressure plate 104 is for bringing the sheet into contact with the separation roller 23 in order to realize the removal of the sheet by the separation roller 23.
[0041]
The separation pressure plate 104 has a mounting portion 105 fixed to the bottom surface portion 100, and the main body portion 106 is urged upward by a separation spring 107 inserted between the bottom surface portion 100 and the main body 106. ing. Thus, the separation pressure plate 104 and the separation roller 23 are in a pressure contact state in a state where the paper feed tray 2 is inserted into the tray insertion port 7.
[0042]
Two conveyance pressure plates 108 and 109 are attached to the front end of the bottom surface portion 100 on both the left and right sides of the separation pressure plate 104. The pressure plates 108 and 109 for conveyance are attached at positions where they contact the conveyance rollers 24 and 25, respectively, when the paper feed tray 2 is inserted into the tray insertion slot 7. The pressure plates for conveyance 108 and 109 are for bringing the paper into contact with the conveyance rollers 24 and 25 in order to realize the assistance of conveyance of the paper by the conveyance rollers 24 and 25.
[0043]
Similarly to the separation pressure plate 104, the attachment pressure portions 108 and 109 are fixed to the bottom surface portion 100, and the main body portions 112 and 113 are connected to the bottom surface portion 100 and the main bodies 112 and 113. The transfer springs 114 and 115 inserted therebetween are biased upward. As a result, the conveyance pressure plates 108 and 109 and the conveyance rollers 24 and 25 are brought into a pressure contact state in a state where the paper feed tray 2 is inserted into the tray insertion port 7.
[0044]
The urging forces of the separating spring 107 and the conveying springs 114 and 115 are set separately. As an example, the biasing force of the separating spring 107 is set to a value larger than the biasing force of the conveying springs 114 and 115. This is because, with regard to the pressure contact state between the roller and the pressure plate, taking out the paper requires a larger pressure contact force than simply assisting the paper conveyance.
[0045]
The urging force of the separating spring 107 and the conveying springs 114 and 115 may be determined in design according to the shape and the like, and the urging force of the separating spring 107 and the urging force of the conveying springs 114 and 115 are the same. It may be a value.
A separation pad 117 is attached to the upper surface 116 of the separation pressure plate 104. The separation pad 117 is made of a material having a predetermined frictional resistance for preventing double feeding when the paper is taken out by the separation roller 23. For example, the separation pad 117 is made of silicon rubber, urethane, cork, or the like.
[0046]
Transport pads 120 and 121 are attached to the upper surfaces 118 and 119 of the transport pressure plates 108 and 109, respectively. The transport pads 120 and 121 are for reducing wear on the peripheral surfaces of the transport rollers 24 and 25. On the other hand, the conveyance rollers 24 and 25 are for assisting the conveyance of the sheet by the separation roller 23 as described above. Therefore, if a frictional load is applied to the transport rollers 24 and 25, paper transport is hindered. Therefore, the transport pads 120 and 121 are made of a flexible material having a frictional resistance necessary and sufficient to generate an auxiliary transport force by the transport rollers 24 and 25. Specifically, it is made of a material having a friction resistance smaller than that of the pressure plates 108 and 109 for conveyance. For example, the transport pads 120 and 121 are made of a PET film, a fluorine-based sheet, or the like.
[0047]
FIG. 5 is a view of the state in which the paper feed tray 2 is inserted into the tray insertion slot 7 as viewed from above.
When the leading end of the paper feed tray 2 is inserted into the tray insertion slot 7, the separation roller 23 and the transport rollers 24 and 25 are respectively connected to the separation pressure plate 104 and the transport via the separation pad 117 and the transport pads 120 and 121, respectively. The pressure plates 108 and 109 are pressed against each other. That is, the separation pressure plate 104 and the conveyance pressure plates 108 and 109 are pushed downward by the separation roller 23 and the conveyance rollers 24 and 25 as indicated by a two-dot chain line and a solid line in FIG.
[0048]
In this state, when the rotation shaft 26 is rotated and sheet feeding is started, the uppermost sheet among the sheets placed on the sheet feeding tray 2 is taken in between the separation roller 23 and the separation pad 117. It is. One sheet is taken in because the frictional resistance of the separation pad 117 is large and the pressure contact state between the separation roller 23 and the separation pad 117 is relatively strong.
[0049]
At the same time, the paper is also taken in between the transport rollers 24 and 25 and the transport pads 120 and 121. Then, the paper is sent out to the conveyance path 90 taken out from the paper feed tray 2.
As described above, the separation pad 117 with which the separation roller 23 comes into pressure contact has a large frictional resistance. As a result, a relatively large frictional resistance acts on the paper. Therefore, the conveying force of the separation roller 23 alone is insufficient for smooth conveyance of the paper. For this reason, the conveyance force of the conveyance rollers 24 and 25 is further applied to assist the conveyance of the sheet by the separation roller 23.
[0050]
If such paper feeding is repeated, the paper placed on the paper feed tray 2 may be lost. Out of paper is recognized when the paper detection switch 22 is not turned on even after the first time has elapsed since the start of paper feeding, as described above. During this time, the separation roller 23 and the transport rollers 24 and 25 rotate in a state where no paper is supplied.
[0051]
On the other hand, the transport pressure plates 108 and 109 are in pressure contact with the transport rollers 24 and 25 via transport pads 120 and 121 made of a material having a smaller frictional resistance than the transport pressure plates 108 and 109. Therefore, the wear on the peripheral surfaces of the transport rollers 24 and 25 can be reduced as compared with the case where the transport rollers 24 and 25 are in direct pressure contact with the transport pressure plates 108 and 109.
[0052]
In addition, since the conveyance pressure plates 108 and 109 are in pressure contact with the conveyance rollers 24 and 25 via the conveyance pads 120 and 121, an auxiliary conveyance force is surely applied to the sheet regardless of the thickness of the sheet. Can be provided. Therefore, sheets with various thicknesses can be targeted for feeding. As a result, the printer can be easily used.
[0053]
In the above description, the separation pressure plate 104 and the conveyance pressure plates 108 and 109 are separate members. But, As a configuration apart from this invention, For example, as shown in FIG. 6, the mounting portions 110 and 111 of the transport pressure plates 108 and 109 may be integrally formed, and the transport pressure plates 108 and 109 may be formed as one component. For example, as shown in FIG. 7, the separation pad 117 and the transport pads 120 and 121 are attached to a single pressure plate 130, and the single pressure plate 130 is shared as the separation pressure plate and the transport pressure plate. Also good. In this case, the urging force by the spring is the same for the separation pressure plate and the conveyance pressure plate. Further, for example, as shown in FIG. 8, two notches 132 and 133 are formed in one pressure plate 131 to form a comb, and three parts 134, 135, and 136 divided by the notches 132 and 133 are formed. May be used as a separation pressure plate and a conveyance pressure plate, respectively.
[0054]
According to this configuration, the separation pressure plate and the conveyance pressure plate can be easily attached to the paper feed tray 2. As a result, the burden on the operator can be reduced.
The description of the embodiment of the present invention is as described above, but the present invention is not limited to the above-described embodiment, and various designs are possible within the scope of the technical matters described in the claims. It is possible to make changes.
[0055]
【The invention's effect】
As described above, according to the present invention, the roller for assisting paper conveyance is pressed against the pad having a frictional resistance necessary and sufficient to generate an auxiliary conveyance force. It is possible to suppress wear on the peripheral surface of the. Therefore, it can contribute to the extension of the life of the roller.
[0056]
In addition, since the roller for assisting the conveyance of the sheet is in pressure contact with the pad, an auxiliary conveyance force can be reliably provided to the sheet regardless of the thickness of the sheet. Therefore, sheets with various thicknesses can be targeted for feeding. Therefore, it can be set as a user-friendly device.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a simplified external configuration of a printer according to an embodiment of the present invention.
FIG. 2 is a view of the printer as viewed from the left side in order to explain the internal configuration of the printer when the cover is closed.
FIG. 3 is a view of the printer as viewed from the left side in order to explain the internal configuration of the printer when the cover is opened.
FIG. 4 is a diagram for explaining a configuration related to paper feeding;
FIG. 5 is a top view of a state in which a paper feed tray is inserted into a tray insertion slot in order to further detail a configuration related to paper feed.
FIG. 6 is a plan view schematically showing a configuration according to another embodiment of a pressure plate provided in a paper feed tray.
FIG. 7 is a plan view showing, in a simplified manner, the configuration according to another embodiment of the pressure plate provided in the paper feed tray.
FIG. 8 is a plan view showing, in a simplified manner, the configuration according to another embodiment of the pressure plate provided in the paper feed tray.
[Explanation of symbols]
1 Main unit
2 Paper tray
7 Tray outlet
20 Paper feeder
23 Separation roller
24, 25 Transport roller
26 Mounting shaft
70 Transport route
104 Pressure plate for separation
105 Separation spring
106,107 Pressure plate for conveyance
108, 109 Spring for conveyance
117 Separation pad
120, 121 Transport pad

Claims (1)

A paper feeding device for supplying paper to a transport path,
A paper placement section for placing paper;
It is attached to the center of the rotary shaft provided in the direction intersecting the paper transport path, rotates with the rotation of the rotary shaft, and the paper to be transported from the paper placed on the paper placement section. A separation roller for taking out and feeding the paper to the transport path;
A separation pad having a predetermined frictional resistance to prevent a plurality of sheets from being taken out by the separation roller, which is pressed against the separation roller with a first urging force by a separation spring across the conveyance path;
A conveying roller attached to both sides of the separating roller of the rotating shaft, rotating with the rotation of the rotating shaft, and for assisting in conveying the sheet taken out from the sheet placing portion by the separating roller;
Friction resistance necessary and sufficient to generate an auxiliary conveyance force by the conveyance roller in a state where the conveyance roller is pressed against the conveyance roller with a second urging force across the conveyance path and pressed against the conveyance roller. have a sheet feeding apparatus which comprises a conveying pad Ru separate member der the above separation pad.

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