JP2005219891A - Paper supply device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper supply device capable of stably supplying paper sheets having high stiffness and large coefficient of friction to a printer one by one and to provide an image forming device having the paper supply device. <P>SOLUTION: This paper supply device is provided with a paper storage part for storing paper sheets to be supplied to an image forming means, a paper sheet feeding means for nipping a paper sheet positioned in the uppermost part among the paper sheets stored in the paper storage part and conveying it toward the image forming means along a predetermined conveyance path, and a paper sheet handling pad in which a paper sheet abutting face on which the paper sheet is abutted so as to incline upward along the conveyance path on the upstream side more than a position where the paper sheet is nipped in the paper sheet feeding means is formed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a paper supply device and an image forming apparatus, and in particular, a paper supply device capable of stably supplying paper having a strong stiffness and a large friction coefficient to an image forming apparatus such as a printer or a copying machine, and the paper supply device. The present invention relates to an image forming apparatus provided.

  2. Description of the Related Art Image forming apparatuses such as printers and copiers are provided with a paper supply device that conveys and supplies paper. The paper supply device normally includes a paper cassette for storing paper, a paper stacking plate that moves up and down in the paper cassette to take either the paper replenishing position or the paper feeding position, and the paper stacking board at the paper feeding position. The paper feeding means is configured to rotate while contacting the upper surface of the paper stacked on the paper stacking plate when it is positioned, and to sequentially convey the paper (see, for example, Patent Document 1 and Patent Document 2).

  Specifically, as shown in FIG. 10A, in the conventional paper supply apparatus 200, when paper is stacked on the paper stacking plate 202 located at the paper replenishing position, the paper stacking plate 202 is shown in FIG. As shown in (B), it automatically rises to the paper feeding position. When the nudger roller 206 of the paper feeding means 204 comes into contact with the upper surface of the paper P located at the uppermost part, the ascent of the paper stacking plate 202 stops. When the nudger roller 206 and the feed roller 208 are rotated in the direction of the arrow from this state, the sheets P are sequentially picked up one by one from the upper side by the nudger roller 206, and are fed and conveyed by the feed roller 208 and the retard roller 210. Yes.

Although not shown, the nudger roller 206, the feed roller 208, and the retard roller 210 are arranged offset to the left or right side with respect to the center line along the transport direction of the paper P. Further, the paper P is guided in the transport direction by a pair of left and right guide walls provided corresponding to the left and right edges along the transport direction.
JP 2003-118844 A JP 2003-118863 A

  By the way, in recent years, it has been studied to use a paper supply device 200 to supply label paper made of glued release paper to a printer instead of normal high-quality paper and to continuously automatically print invoices and slips with the printer. Yes.

  The label paper is composed of a label body having a printing surface on which characters and the like are printed, and a separator on which the label body is detachably attached, and has a characteristic that it is firm compared to plain paper. Yes. In the case where a plurality of slips that can be separated from each other by one sheet of label paper are used, that is, in a structure in which a plurality of label bodies are attached to a single separator so as to be peelable independently, Each part of the surface has a characteristic that there is a part having a higher friction coefficient (friction coefficient with other label sheets to be laminated) than other parts. Specifically, the friction coefficient is higher at the boundary between adjacent label bodies than at other portions.

  Therefore, when trying to supply the label paper using the paper supply device 200, the label paper should be sent out one by one, but there may be a conveyance failure such as sending out two or three sheets at a time.

  The present invention has been made to solve the above-described problem. In the case where a sheet having a strong stiffness and a large friction coefficient such as the label sheet is supplied to an image forming apparatus such as a printer or a copying machine, the sheet is formed. An object of the present invention is to provide a sheet supply device that can stably supply a sheet one by one and an image forming apparatus having the sheet supply device.

  According to the first aspect of the present invention, a sheet storage unit that stores a sheet supplied to the image forming unit and a sheet positioned at the top of the sheets stored in the sheet storage unit are sandwiched, and a predetermined transport path A sheet delivery means that conveys the sheet toward the image forming means, and an upstream side of the position where the sheet is sandwiched in the sheet delivery means so as to incline upward along the conveyance path. The present invention relates to a paper supply device comprising a paper spreading pad on which a paper contact surface with which residual water abuts is formed.

  The paper supply device is used to supply paper to image forming means in an image forming apparatus such as a printer or a copying machine.

  In the paper supply device, the paper spreading pad includes a paper contact surface with which the paper transported by the paper delivery means comes into contact, and the paper contact surface is located more than a position where the paper is sandwiched by the paper delivery means. Since the sheet is provided on the upstream side, the sheet conveyed by the sheet feeding unit first comes into contact with the sheet contact surface of the sheet separating pad. The residual water contact surface is inclined upward along the paper conveyance path, so that even when a plurality of papers are sent out at once, the leading edge of the paper located above The leading edge of each sheet is shifted so that is positioned in front of the leading edge of the sheet positioned below. Accordingly, only the sheet located at the uppermost part is fed with the conveying force from the sheet sheet feeding means and is sent out of the sheet storage unit. In this way, it is possible to prevent the double feed from occurring even on a sheet having a strong stiffness and a large frictional force on the surface, and can be stably fed out one by one to the image forming apparatus.

  According to a second aspect of the present invention, in the paper supply device according to the first aspect, the paper feeding means is provided so as to contact a paper located at the uppermost part among the papers stored in the paper storage unit. At least one nudger roller, at least one feed roller located downstream of the nudger roller along the conveyance path, and at least one retard roller located on the opposite side of the feed roller across the conveyance path; The feed roller and the retard roller sandwich the paper conveyed by the nudger roller and send it out toward the image forming means, and the paper contact pad has the paper contact surface, A paper supply device provided so as to be positioned upstream from the position where the paper is sandwiched between the feed roller and the retard roller. To.

  In the paper supply device, the paper stored in the paper storage unit is fed between the feed roller and the retard roller by the nudger roller. Then, the feed roller and the retard roller feed out toward the image forming apparatus.

  Therefore, if the width of the nudger roller, feed roller, and retard roller is sufficiently narrow compared to the width of the paper, the width of the portion where the nudger roller, feed roller, and retard roller rub against the paper can be minimized. , Less paper damage. In addition, since the feed roller and the retard roller themselves have a function of scooping paper, the paper scooping pad has a paper scooping function, and more reliably than the paper feeding device according to claim 1. Double feeding can be prevented.

  The nudger roller, the feed roller, and the retard roller can be configured as one unit held by one member.

  According to a third aspect of the present invention, in the paper supply apparatus according to the first or second aspect, the paper supply device has a dynamic friction coefficient between the paper contact surface of the paper separation pad and the paper of 0.5 to 1. Relates to the device.

  If the dynamic friction coefficient between the paper contact surface and the paper is too large or too small, the paper may be damaged when the paper abuts against the paper spreading pad, or multiple paper feeds may occur. However, in the paper supply apparatus, since the dynamic friction coefficient between the paper contact surface and the paper is set within the above range, it is possible to effectively prevent the paper from being damaged or double fed.

  According to a fourth aspect of the present invention, in the paper feeding device according to any one of the first to third aspects, the paper abutting surface is configured such that the paper abutting pad accommodates the paper in the paper accommodating portion. The present invention relates to a sheet supply device arranged so that an angle between the uppermost sheet and a sheet positioned at the top is in a range of 140 to 160 degrees.

  Even if the angle between the paper contact surface of the paper spreading pad and the uppermost paper is too large or too small, the paper may be damaged when the paper contacts the paper separation pad, However, in the paper supply apparatus, the dynamic friction coefficient is set in the above range, so that it is possible to effectively prevent the paper from being damaged or double feed.

  According to a fifth aspect of the present invention, there is provided a paper feeding device according to any one of the first to fourth aspects, wherein the paper spreading pad is formed of a foamed elastomer.

  In the paper supply device, the paper spreading pad is formed of a foamed elastomer, so that the surface is soft. Therefore, it is particularly preferable in that the sheet abutting on the sheet separation pad is not damaged.

  According to a sixth aspect of the invention, there is provided an image forming apparatus comprising: the paper supply device according to any one of the first to fifth aspects; and an image forming unit that forms an image on the paper supplied from the paper supply device. About.

  In the image forming apparatus, sheets are fed one by one to the image forming unit without causing double feeding of the sheets, so that the sheets are not discharged without forming an image by the image forming unit. Therefore, it is preferable.

  A seventh aspect of the present invention relates to an image forming apparatus according to the sixth aspect, wherein the image forming means is an electrophotographic image forming means.

  Since the image forming apparatus forms an image by electrophotography, a high-quality image can be formed at high speed.

  The invention according to claim 8 is the image forming apparatus according to claim 6 or 7, wherein the paper has a label body having an image forming surface on which an image is formed, and the label body is detachably attached. The present invention relates to an image forming apparatus that is a label sheet including a separator.

  According to the present invention, there is provided a paper supply device capable of stably supplying the paper one by one and the paper supply device even when supplying paper having a high stiffness and a large friction coefficient to a printer or a copying machine. In addition, an image forming apparatus is provided that can be preferably used for sheets that are stiff and have a large friction coefficient.

1. Embodiment 1
An example in which the paper supply apparatus of the present invention is applied to a laser printer 10 will be described with reference to FIGS. The laser applicator 10 is an example of an image forming apparatus according to the present invention.
(1) Configuration of Laser Printer 10 As shown in FIG. 1, the laser printer 10 includes a printer main body 12 and a paper supply device 14 that supplies paper to the printer main body 12.
(1-1) Configuration of Printer Main Body 12 The printer main body 12 includes an image processing unit 18, an image output unit 20, and a housing 16 that accommodates them.

  Image data (in this embodiment, slip data described later) is input to the image processing unit 18 from a host computer such as a personal computer or a communication line. The image processing unit 18 performs predetermined image processing on the input image data as necessary, and drives the image output unit 20 based on the image data.

  The image output unit 20 includes a photosensitive drum 22 that is irradiated with image light in a uniformly charged state to form an electrostatic latent image on the surface, a charging device 24 that uniformly charges the surface of the photosensitive drum 22, Based on the image data from the image processing unit 18, an optical scanning device 26 that irradiates the photosensitive drum 22 with image light, and a toner attached to the electrostatic latent image formed on the surface of the photosensitive drum 22, A developing device 28 that forms a toner image on the surface, a transfer device 32 that transfers the toner image on the photosensitive drum 22 to the paper supplied by the registration roller 30, and a separation charging device that performs static elimination on the paper on which the toner image has been transferred. 34, a fixing device 36 for fixing the toner image transferred to the paper to the paper, and a cleaning device 38 for removing the toner remaining on the surface of the photosensitive drum 22 after the toner image is transferred to the paper. Eteiru.

  The photosensitive drum 22 has a drum shape, and a photosensitive layer is formed on the outer peripheral surface. Then, exposure is performed in a state where the photosensitive layer is uniformly charged, whereby the potential of the exposed portion is attenuated. The photosensitive drum 22 is rotationally driven at a predetermined rotational speed in the counterclockwise direction in FIG. 1 as indicated by an arrow.

  The charging device 24 has a roller shape and contacts the surface of the rotating photosensitive drum 22 to charge the surface of the photosensitive drum 22 almost uniformly.

  The optical scanning device 26 forms an electrostatic latent image by irradiating the photosensitive drum 22 with a laser beam LB corresponding to the image data processed by the image processing unit 18, that is, image light. The optical scanning device 26 emits a laser beam LB from a semiconductor laser (not shown) based on the image data input from the image processing unit 18, and after this laser beam LB is deflected and scanned by the rotary polygon mirror 26A, The surface of the photosensitive drum 22 is exposed by the reflection mirrors 26B and 26C. As a result, the potential of the exposed portion on the surface of the photosensitive drum 22 is attenuated, and an electrostatic latent image is formed on the outer peripheral surface of the photosensitive drum 22.

  The developing device 28 includes a cylindrical developing roller 28 </ b> A disposed so as to face the photosensitive drum 22 in close proximity. The developing bias electric field formed by the developing bias voltage applied between the developing roller 28A and the photosensitive drum 22 transfers the charged toner to the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 22, and allows A toner image that is a visual image is formed.

  The transfer device 32 has a roller shape and is disposed so as to face the photosensitive drum 22. The transfer device 32 forms a transfer electric field between the photosensitive drum 22 and the toner image is transferred to a sheet passing between the transfer device 32 and the photosensitive drum 22. To the transfer device 32, a sheet whose conveyance timing and posture are corrected by the registration roller 30 is conveyed. The paper is conveyed to the registration roller 30 from the paper supply device 14 or a paper feed cassette 50 (described later).

  The separation charging device 34 is disposed in the vicinity of the transfer device 32.

  The cleaning device 38 is provided on the downstream side of the separation charging device 34 along the rotation direction of the photosensitive drum 22, and the sheet on which the toner image is transferred by the transfer device 32 is discharged by the separation charging device 34 and separated. It has a function of removing toner remaining on the surface of the photosensitive drum 22.

  On the other hand, the paper separated from the photosensitive drum 22 by the separation charging device 34 reaches the fixing device 36. The fixing device 36 includes a heating roller 36A and a pressure roller 36B, and heats and pressurizes the sheet by the heating roller 36A and the pressure roller 36B to fix the toner image on the sheet.

  A discharge tray 44 is provided on the upper surface of the housing 16, and a discharge conveyance path 40 is provided between the fixing device 36 and the discharge tray 44. The discharge conveyance basket 41 opens on the side wall surface of the discharge tray 44 and forms a discharge port.

  The sheet on which the toner image is fixed by the fixing device 36 is nipped and conveyed by the discharge roller 42 through the discharge conveyance path 40, and is discharged from the outlet of the discharge conveyance path 40 to the discharge tray 44.

  Further, the printer main body 12 includes a double-sided conveyance unit 46 that communicates the exit of the discharge conveyance path 40 and the registration roller 30. The duplex conveyance unit 46 is provided with three pairs of conveyance rollers 48 at regular intervals.

  In the case of duplex printing, the sheet on which the toner image is fixed on the front side by the fixing device 36 is once conveyed to the exit of the discharge conveyance path 40 by the discharge roller 42. The discharge roller 42 rotates reversely immediately before the sheet is completely discharged from the discharge conveyance and the outlet 40, and the sheet is introduced to the outlet side of the double-side conveyance unit 46 and guided to the registration roller 30. Then, it is again introduced into the transfer device 32 by the registration roller 30. As a result, the sheet is introduced into the transfer device 32 with the front and back reversed, and the toner image is transferred and fixed on the back side.

  The photosensitive drum 22, the charging device 24, the developing device 28, and the cleaning device 38 are accommodated in a process cartridge 40 and integrated. The process cartridge 40 is configured to be movable to a retracted position (not shown). When the process cartridge 40 is located at the retracted position, the photosensitive drum 22 is separated from the transfer device 32 and a work space for exchanging the transfer device 32 is formed in the housing 16.

  The printer main body 12 is provided with a paper feed conveyance path 51 that conveys the paper supplied from the paper supply device 14 toward the registration rollers 30.

  The printer main body 12 includes a paper feed cassette 50. The paper feed cassette 50 is formed in a box shape that stores a plurality of sheets in a stacked state. The paper stored in the paper feed cassette 50 is discharged from the paper feed cassette 50 one by one by the feed roller 52. Then, a conveyance roller 54 disposed in the vicinity of the feed roller 52 supplies the paper discharged one by one by the feed roller 52 to the registration roller 30 through the paper feed conveyance path 51.

The printer body 12 includes a manual feed tray 56. By expanding the manual feed tray 56 substantially horizontally as shown in FIG. 1, sheets of different sizes and materials such as OHP sheets and postcard sheets can be introduced into the printer main body 12. The paper introduced from the manual feed tray 56 is supplied to the registration roller 30 via the paper feed roller 58. The manual feed tray 56 is stored in a folded state in a storage portion formed on the outer surface of the housing 16 when not in use.
(1-2) Configuration of Paper Supply Device 14 Next, the paper supply device 14 will be described in detail. For convenience, the sheet conveyance direction (initial conveyance direction) indicated by an arrow A in each figure will be referred to as the front side, and the direction indicated by the arrow B orthogonal to the arrow A will be described as the left side.

  The paper supply device 14 includes a main body portion 60 on which the printer main body 12 is placed in a positioned state, and a paper storage portion 62 provided so as to be attachable to and detachable from the main body portion 60. The main body portion 60 includes a housing 64 formed in a rectangular box shape that opens to the rear, and the sheet storage portion 62 can be attached to and detached from the housing 64 by moving in the front-rear direction.

  As shown in FIG. 1, a paper feed conveyance path 63 for feeding the paper P accommodated in the paper accommodation section 62 to the printer main body 12 through the paper feed conveyance path 51 is provided on the front side of the upper end of the housing 64. Yes.

  A roller unit 66 is disposed in the vicinity of the paper feed conveyance path 63 at the upper end of the housing 64. As shown in FIGS. 2 and 3, the roller unit 66 includes a nudger roller 68, a feed roller 70, and a retard roller 72.

  As shown in FIGS. 3 and 4, the feed roller 70 is rotatably supported by a side frame (not shown) in which a support shaft 70 </ b> A is fixedly provided in the housing 64, and a motor (not shown). Rotate in the direction indicated by arrow C in FIG. An arm member 76 is connected to the support shaft 70A via a bearing 74 so as to be relatively rotatable.

  The arm member 76 is configured by connecting a pair of left and right leg pieces 76A by a connecting portion 76B, and is supported on the support shaft 70A by a bearing 74 provided in the vicinity of the front end of each leg piece 76A.

  In the vicinity of the rear end of each leg piece 76A of the arm member 76, a support shaft 68A of the nudger roller 68 is rotatably supported. Thereby, the nudger roller 68 rotates about the support shaft 68 </ b> A and revolves around the support shaft 70 </ b> A of the feed roller 70. Further, interlocking gears (not shown) are provided at positions corresponding to each other of the support shaft 68A and the support shaft 70A, and each interlocking gear is an intermediate gear (not shown) rotatably supported by the leg piece 76A. (Not shown). Thus, when the feed roller 70 is rotated in the direction of arrow C by the operation of the motor, the nudger roller 68 is rotated in the same direction as indicated by the arrow D in FIG.

  The retard roller 72 is disposed immediately below the feed roller 70, and its support shaft 72A is supported by a pair of left and right support arms (not shown) supported so as to be able to swing substantially vertically with respect to the front frame 78 (see FIG. 2). It is pivotally supported. The retard roller 72 is provided with a one-way so that a certain load is applied when the retard roller 72 rotates in the paper transport direction. When two sheets jump between the feed roller 70 and the retard roller 72, both sheets are prevented from being sent downstream by the load applied to the retard roller 72 by the one-way. On the other hand, when only one sheet jumps between the feed roller 70 and the retard roller 72, the one-way torque is lost and the sheet is sent downstream.

  As shown in FIG. 2, a roller holding member 80 is rotatably supported on the side frame of the main body 60. The roller holding member 80 includes a first arm 80A that can be engaged with the support shaft 68A of the nudger roller 68, and a second arm 80B that can be engaged with the support shaft 72A of the retard roller 72. In a state in which the sheet storage portion 62 is detached from the main body portion 60, the roller holding member 80 causes the nudger roller 68 to move upward from the sheet feeding position shown in FIG. 4B by the urging force of the torsion spring 81. Hold on.

  On the other hand, when the paper storage section 62 is mounted on the main body section 60, the roller holding member 80 resists the urging force of the torsion spring 81 by the second arm 80 </ b> B being pressed forward by the paper storage section 62. The first arm 80A is rotated in a direction to move downward, and the nudger roller 68 is allowed to move downward. As a result, the nudger roller 68 moves downward due to its own weight and the own weight (moment) of the arm member 76 and is pressed against the upper surface of the sheet. Further, the second arm 80B pressed forward rotates to press the support shaft 72A substantially upward, and the retard roller 72 supported by the support arm as described above is brought close to the feed roller 70.

  In addition, the roller unit 66 includes a weight member 82 that protrudes rearward and attached to the arm member 76. This increases the load with which the nudger roller 68 is pressed against the paper. Specifically, the load with which the nudger roller 68 is pressed against the paper is approximately 0.98 N when the weight member 82 is not provided, but increases to approximately 2.55 N when the weight member 82 is provided.

  As described above, the roller unit 66 is configured to be positioned at the paper feeding position when the paper storage unit 62 is attached to the main body 60. In the paper feeding position, the nudger roller 68 is pressed against the upper surface near the front edge of the paper, and the feed roller 70 and the retard roller 72 are positioned in front of the front edge of the paper. Further, as shown in FIG. 3, the nudger roller 68, the feed roller 70, and the retard roller 72 are arranged at positions offset by the same amount on the left side with respect to the center line along the sheet conveyance direction (front-rear direction). Yes.

  As shown in FIG. 4B, in the roller unit 66, the nudger roller 68 feeds the paper P forward by rotating in the direction of arrow D while contacting the upper surface of the uppermost paper P. The feed roller 70 and the retard roller 72 are rotated in the direction of arrow C. The feed roller 70 rotating in the direction of arrow C further conveys the paper sandwiched between the retard roller 72 and supplies it to the registration roller 30 of the printer main body 12 through the paper feed conveyance path 53. Therefore, in a narrow sense, the nudger roller 68, the feed roller 70, and the retard roller 72 correspond to “paper feeding means” in the present invention, but in a broad sense, it is understood that the entire roller unit 66 corresponds to “paper feeding means” in the present invention. It is also possible.

  In addition, as shown in FIG. 2, a mounting plate driving unit 84 is provided in the housing 64. The mounting plate drive unit 84 is attached to the front frame 78 and includes a motor 84A and a chuck unit 84B that is rotated by the motor 84A. The chuck portion 84 </ b> B is configured to mesh with the placement plate up / down mechanism of the paper placement plate 88 when the paper storage portion 62 is attached to the main body portion 60. Therefore, when the paper storage portion 62 is mounted on the main body portion 60 and the motor 84A is rotated, the chuck portion 84B is also rotated, and the paper placement plate 88 is raised.

  In the housing 64, a paper position detection sensor (not shown) for detecting the height of the paper P is provided. The paper position detection sensor outputs the height of the paper P to a control circuit (not shown). When a signal corresponding to the fact that the paper placed on the paper placement plate 88 has reached a predetermined height is input from the paper position detection sensor, the control circuit stops the motor 84A of the placement plate drive unit 84. . The control circuit also rotates the motor 84A when a signal corresponding to a decrease in the height direction of the sheet located at the uppermost position by a predetermined amount is input from the sheet position detection sensor. The paper placing plate 88 is raised again. The paper position detection sensor can be attached to, for example, an upper frame (not shown) that forms the ceiling of the arm member 76 or the main body 60.

  On the other hand, as shown in FIG. 2, the paper storage unit 62 includes a paper cassette 86. The paper cassette 86 has an opening 86 </ b> A that opens upward and a front wall 86 </ b> B. The paper cassette 86 is a rectangular box that forms the outer shell of the paper storage unit 62, and stores the paper P. The paper cassette 86 is formed so as to accommodate a larger amount of paper P than the paper feed cassette 50. The paper cassette 86 is replenished with paper P from the opening 86 </ b> A while being detached from the main body 60. In the paper cassette 86, a paper placement plate 88 is provided so as to be vertically movable while facing the bottom surface of the paper cassette 86. The paper placement plate 88 corresponds to a “paper stacking unit” in the present invention, and the paper P accommodated in the paper cassette 86 is stacked on the paper placement plate 88 in a stacked state.

  The paper placement plate 88 has a width of the front end portion 88A corresponding to the width in the left-right direction of the paper, and at the same time, the portion excluding the front end portion 88A is narrower than the paper and is formed in a substantially T-shaped planar shape as a whole. Has been. Therefore, the paper placing plate 88 supports the paper over the entire width at the front end portion 88A (step forming member 90 described later) located almost directly below the nudger roller 68 with the paper storage portion 62 mounted on the main body portion 60. Is configured to do.

  Below the paper placement plate 88, a placement plate up / down mechanism (not shown) for raising the paper placement plate 88 is provided. The mounting plate up-and-down mechanism engages with the chuck portion 84B of the mounting plate driving unit 84 in a state where the paper storage unit 62 is mounted on the main body unit 60, and increases the rotational motion transmitted from the mounting plate driving unit 84. Movement, in other words, movement in a direction away from the bottom surface of the paper cassette 86 is converted to raise the paper placement plate 88. Therefore, when the paper storage portion 62 is mounted on the main body portion 60, the chuck portion 84B and the placement plate up-and-down mechanism described above are engaged, and the paper placement plate 88 is a paper feed position where the paper P is pressed against the nudger roller 68. It is automatically raised until it is held at this position. Then, as the number of sheets P decreases, the sheet placing plate 88 rises again and holds the sheet feeding position. On the other hand, when the paper storage portion 62 is detached from the main body portion 60, the meshing between the placement plate up-and-down mechanism and the chuck portion 84B is released, and the paper placement plate 88 is self-weighted to the paper replenishment position near the bottom surface of the paper cassette 86. Fall by.

  Further, as shown in FIGS. 2 and 3, a step forming member 90 is attached on the front end 88 </ b> A of the sheet placing plate 88. The step forming member 90 is a wedge-shaped member that increases in thickness along the feeding direction A of the paper P, in other words, forward, and extends along the front end portion 88A. The step forming member 90 extends over the entire front end portion 88A, and supports the front end portion of the paper stacked on the paper placement plate 88 from below over the entire width. In other words, the front end portion of the paper forms a step. It is loaded on the member 90.

  At the front end portion of the upper surface of the step forming member 90, a horizontal surface 90A substantially parallel to the upper surface of the sheet placing plate 88 is formed, and an inclined surface 90B inclined backward is formed continuously with the horizontal surface 90A. ing. At the rear end of the step forming member 90, a vertical surface 90C is formed continuously with the inclined surface 90B along a direction substantially orthogonal to the upper surface of the sheet placing plate 88.

  A height h1 from the upper surface of the sheet placing plate 88 to the horizontal plane 90A, a height h2 of the vertical plane 90C, a length L1 in the front-rear direction of the horizontal plane 90A, and a length L2 along the front-rear direction of the inclined plane 90B (both shown in FIG. 4 (A) is determined according to the strength of the waist of the paper, but in the first embodiment, for example, for a delivery slip paper P (described later) having a length in the front-rear direction of about 210 mm (A4 size). , Height h1 = 12 mm, height h2 = 4 mm, length L1 = 30 mm, and length L2 = 20 mm. Further, the horizontal plane 90A is set to have a length L1 so as to support a portion including a contact portion of the paper with the nudger roller 68 in the front-rear direction in a state where the paper storage portion 62 is mounted on the main body portion 60. Yes.

  By providing the step forming member 90 on the sheet placing plate 88 in this way, the stacked sheets P can be conveyed while being separated one by one.

  Specifically, as shown in FIG. 5A, the sheets P stacked in a stacked state on the sheet placing plate 88 and the step forming member 90 are the upper surface of the sheet placing plate 88 and the inclined surface of the step forming member 90. 90B and the horizontal plane 90A are deformed, and the laminated state collapses so as to be displaced in the front-rear direction. That is, the step forming member 90 is configured to continuously incline imaginary straight lines connecting the front and rear edges of the stacked sheets (groups) with respect to the vertical direction so that the upper side is located behind the lower side. Then, the laminated state of the paper is destroyed. This makes it easier to separate the stacked sheets one by one.

  In addition, the front end portion of the sheet P is deformed so as to follow the inclined surface 90B and the horizontal surface 90A of the step forming member 90. In other words, the front end portion of the sheet deformed upward on the inclined surface 90B (self-weight or nudger roller). 68. When the paper P is relatively stiff, the force that the front end of each paper P is scattered in the vertical direction by the waist (elasticity) of the paper P itself, in other words, In this case, a force is generated to make the stacked sheets P one by one. Accordingly, the step forming member 90 also has a function of making it easy to spread the leading edge portion, which is the free end of the sheet, in the vertical direction. Then, as shown in FIGS. 5B and 5C, when the paper placement plate 88 is raised and the nudger roller 68 is brought into contact with the upper surface of the uppermost sheet, the sheet P is brought into contact with the nugger roller 68 ( The dispersal state is corrected at the front and rear direction and the contact portion in the left and right direction), but the surface of the step forming member 90 is lifted from the lower sheet P by its own waist (elasticity) at a portion behind the horizontal plane 90A. For this reason, friction between the upper and lower sheets is reduced, and the lower sheet is prevented from being sent out following the upper sheet.

  Further, the step forming member 90 is provided on the front end 88A of the sheet placing plate 88, that is, on the sheet conveying side, thereby functioning as a weir with respect to the sheet P to be conveyed and directly conveyed by the nudger roller 68. Is prevented from being conveyed in the direction of arrow A following the upper sheet.

  In the first embodiment, the step forming member 90 can be attached to and detached from the paper placing plate 88. Specifically, as shown in FIGS. 2 and 3, mounting holes 90D are provided in the vicinity of both longitudinal ends of the step forming member 90, and the step forming members 90 are inserted into the mounting holes 90D, respectively. The screw 102 (see FIG. 3) is fixedly and detachably attached to the paper placing plate 88. However, the step forming member 90 may be formed integrally with the sheet placing plate 88, or may be formed by bending the front end portion 88A upward.

  Further, a pair of left and right guide members 92 are provided in the paper cassette 86 as shown in FIG. Each guide member 92 has a substantially flat guide wall 92A along the front-rear direction and the up-down direction, and each guide wall 92A corresponds to the left and right edges of the paper stacked on the paper placement plate 88, respectively. Are arranged. That is, the facing distance between the pair of guide walls 92A corresponds to the width in the left-right direction of the sheet. Thus, the sheet is conveyed forward while being guided by the pair of guide walls 92A.

  Each guide member 92 can be changed in the left-right mounting position with respect to the paper cassette 86 in accordance with the size of the paper. For this reason, the front end of each guide member 92 (guide wall 92 </ b> A) is located behind the front end portion 88 </ b> A of the sheet placing plate 88. In other words, the pair of left and right guide walls 92 </ b> A are provided behind the nudger roller 68 (upstream in the sheet conveyance direction with respect to the nudger roller 68) with the sheet storage unit 62 mounted on the main body 60.

  Further, each guide member 92 has a lid placement portion 92B extending outward in the left-right direction from the upper end portion of each guide wall 92A, and after extending inward in the left-right direction from the rear end portion of each guide wall 92A. Wall 92C. A lid-like member 96 is bridged and placed on each lid placement portion 92B. Each rear wall 92C has a function of restricting the backward movement of the paper P. The front surface of each rear wall 92C is located slightly behind the rear end portion of each lid placing portion 92B. Further, the rear part of the upper end edge of the guide wall 92A and the rear wall 92C behind the rear end portion of the lid placing portion 92B is formed slightly lower than the upper surface of the lid placing portion 92B, and the lid placing portion 92B A step is formed between the two.

  Further, as shown in FIGS. 2 and 3, the tongue portion 86 </ b> C projects obliquely toward the front upper side from between the left edge of the paper in the left-right direction of the front wall 86 </ b> B of the paper cassette 86 and the feed roller 70 installation position. ing. A sheet-shaped or pad-shaped sheet-spreading pad 94 is fixed to the right end portion of the upper surface of the tongue portion 86C. The sheet contact surface 94A, which is the upstream surface of the sheet spreading pad 94 with respect to the conveyance direction A of the sheet P, is a surface on which the sheet P conveyed by the nudger roller 68 first contacts, and in FIG. As shown in FIG. 5, the position where the paper P is sandwiched between the feed roller 70 and the retard roller 72, that is, the position upstream of the position where the feed roller 70 and the retard roller 72 are in contact, and the transport direction A It is formed so as to incline upward along the line. As shown in FIG. 7, the angle α formed by the uppermost sheet P and the sheet contact surface 94A is preferably 140 to 160 degrees as shown in FIG. 7, and 145 degrees is an optimum value. When the frictional resistance of the contact surface 94A is high, the optimum value may be 155 degrees. If the angle α is within the above range, it is preferable that the sheet P does not hit the sheeting pad 94 and is damaged, or the sheet P is not double-fed. However, the preferred range of the angle may vary depending on the dynamic friction coefficient between the paper P and the paper contact surface 94A, and is not necessarily limited to the above range, and may be set as appropriate according to the dynamic friction coefficient. Can do. Further, the sheet contact surface 94A preferably has a dynamic friction coefficient with the sheet of 0.5 to 1.0, particularly preferably 0.7 to 0.9, and 0.8 to 0.9. Most preferred. Examples of the material of the paper spreading pad 94 include foamed elastomer sheets such as foamed polyurethane resin. Specifically, EX foam (trade name) manufactured by Toppan Foam Co., Ltd. can be used.

  Since the paper spreading pad 94 is provided on the upper surface of the tongue portion 86C as described above, when the paper storage portion 62 is mounted on the main body portion 60, it overlaps the retard roller 72 in a side view and the nudger roller 68. Is arranged so that the sheet conveyed by the sheet abuts before the sheet contacts the feed roller 70. Accordingly, the sheet separating pad 94 itself is adjacent to the roller unit 66 corresponding to the sheet feeding means in the present invention, and the sheet contact surface 94A is more transported than the position where the feed roller 70 and the retard roller 72 are in contact with each other. Located slightly upstream from A. Accordingly, as shown in FIG. 6A, even when a plurality of sheets P are conveyed by the nudger roller 68, the sheets P come into contact with the sheet separation pad 94 and the leading ends of the respective sheets P are shifted. As shown in FIG. 5B, only one sheet P located at the uppermost portion to which the conveying force is directly applied by the nudger roller 68 is sandwiched between the feed roller 70 and the retard roller 72 and sent out. It is. In other words, the sheet spreading pad 94 has a function of shifting the leading edge of the sheet before being sandwiched between the feed roller 70 and the retard roller 72 as described above, and the sheet with which the leading edge is in contact by frictional force (conveying force between the sheets). Therefore, the plurality of stacked sheets P are separated one by one by the sheet-spreading pad 94, in other words, the sheets are separated. Further, as described above, since the paper P is easily separated one by one by the step forming member 90, the paper supply device 14 according to the first embodiment reliably separates the paper P one by one. Can be transported. The step forming member 90 has a function of easily separating the stiff paper (even if the friction coefficient is relatively large), whereas the paper spreading pad 94 depends on characteristics such as the strength of the back. It has a function to facilitate separation.

  Further, the sheet spreading pad 94 is disposed so as to maintain the contact state with the sheet P even after the front end of the sheet P is sandwiched between the feed roller 70 and the retard roller 72. Accordingly, the roller unit 66 (particularly the nudger roller 68) is offset with respect to the center line along the front-rear direction of the sheet, so that the sheet P is subjected to a force to skew so that the left side precedes it. The paper spreading pad 94 has a function of antagonizing the force by the frictional force with the paper P and suppressing the skew of the paper.

  As shown in FIGS. 2 and 3, the sheet storage unit 62 includes a lid-like member 96. The lid member 96 includes an attachment portion 98 attached to the paper cassette 86 in a positioning state, an upper surface of the paper stacked on the paper placement plate 88 in a state where the paper storage portion 62 is attached to the main body portion 60, and a predetermined amount. In other words, it includes a bending deformation restricting portion 100 that is opposed in a non-contact state.

  The attachment portion 98 is formed in a substantially rectangular flat plate shape, has a bridge portion 98A that is placed on the lid placement portion 92B of the pair of guide members 92, and has a substantially full width in the left-right direction from the rear end of the bridge portion 98A. A first engaging portion 98B hanging downward, and a second engaging portion 98C extending further downward from a position corresponding to the pair of rear walls 92C at the lower end of the first engaging portion 98B. ing.

  The attachment portion 98 has a bridge portion 98A such that the first engagement portion 98B is located on the rear side of each lid placement portion 92B and the second engagement portions 98C are located on the front side of the corresponding rear wall 92C. The left and right ends of the paper are placed on the corresponding lid placement portions 92B and mounted on the paper cassette 86. As a result, the lid-like member 96 is mounted on the paper cassette 86 (paper housing portion 62) in a positioning state in which movement in the front, rear, left, and right directions is restricted. Further, since the lid-like member 96 is formed so as to be detachable with respect to the paper accommodating portion 62, when the paper cassette 86 of the paper accommodating portion 62 is replenished with paper, if the lid-like member 96 is removed, the paper cassette The paper supply to 86 is not hindered.

  Furthermore, a notch portion 98D that opens forward is provided on the left portion of the bridge portion 98A, and a connecting portion 98E is suspended from the rear edge portion of the notch portion 98D. And the bending deformation control part 100 is extended ahead from the lower end part of this connection part 98E. In the present embodiment, the bending deformation restricting portion 100 is formed integrally with the bridge portion 98A by pressing or the like. The bending deformation restricting portion 100 is formed in a substantially rectangular flat plate shape in plan view, and in the attached state, the front edge thereof substantially coincides with the front end of the guide wall 92A. That is, the bending deformation restricting portion 100 is disposed so as to face the upper surface of the paper on the upstream side in the paper transport direction with respect to the nudger roller 68. Further, in the mounted state, the bending deformation restricting portion 100 corresponds to a substantially intermediate portion between the left edge of the sheet and the sheet separating pad 94 and has a right edge left of the center line in the front-rear direction of the sheet. And slightly to the right with respect to the nudger roller 68.

The bending deformation restricting portion 100 includes a rear end portion 100A that is substantially parallel to the bridge portion 98A, and a front end portion 100B that is continuous with the front end of the rear end portion 100A and is inclined upward toward the front. Therefore, the bending deformation restricting unit 100 is configured so that the rear end portion 100A is substantially parallel to the paper P stacked on the paper placing plate 88 in a state where the lid-like member 96 is attached to the paper accommodating portion 62. Relative to P. On the other hand, the front end portion 100B has an inclination angle so that the paper bundle of the paper P deforms following the step forming member 90 and does not come into contact with the front end portion of the paper bundle that is pressed by the nudger roller 68 and floats. Then, as shown in FIG. 4B, the dimensions of the guide member 92 so that the facing distance G between the rear end portion 100A of the bending deformation restricting portion 100 and the uppermost sheet P is within a predetermined range. The dimensions of each part of the lid-like member 96 such as the height of the connecting part 98E and the thickness of the bridge part 98A are set. The range of the facing gap G is the gap G ₁ (for example, 3 mm) when the paper storage unit 62 is mounted on the main body 60 and the paper placement plate 88 stops after being raised, and the paper placement plate 88 when the paper is reduced. Is a range between the distance G ₂ (for example, 5 mm) just before the rise again. Specific numerical values are set according to the strength of the paper. Further, in the present embodiment, as will be described later, since the delivery slip sheet P that is relatively stiff is transported, the range of the delivery slip sheet P that floats from the step forming member 90 (the lower layer paper that follows) is relatively wide. At the same time, the distance G is set to be relatively large in consideration of the fact that the amount of floating increases.

  As described above, the lid-like member 96 has the first engagement portion 98B and the second engagement portion 98C formed by bending the rear end portion of the attachment portion 98 downward, and the bending deformation restricting portion also at the front end portion. Since 100 is integrally formed, the rigidity in the thickness direction is high. Further, the bending deformation restricting portion 100 is formed so as to face the uppermost sheet P when the sheet accommodating portion 62 is mounted on the main body 60 in a state where the bundle of sheets P is accommodated in the sheet cassette 86. Yes. Therefore, when the paper storage portion 62 is mounted on the main body portion 60, the upward deformation of the paper P is restricted by the lid member 96, specifically, the bending deformation restricting portion 100, as shown in FIG. For example, as shown in FIG. 8, when the sheet P is skewed so that the left side is preceded, the rear left corner P1 is pressed against the left guide wall 92A so that the rear left corner P1 and the nudger roller 68 When the sheet comes into contact with the bending deformation restricting portion 100 of the lid-like member 96 along with the bending deformation, the bending deformation is restricted.

  The laser printer 10 according to the first embodiment is a laser printer that forms an image on a delivery slip sheet P. Specifically, slip data including delivery destination data, client data, delivery data, and the like is provided on the delivery slip sheet P. Is used to create a delivery slip for home delivery.

  As shown in FIG. 9, the delivery slip sheet P is a label sheet (a release sheet with glue) composed of a separator S and a label body R that is detachably attached to the separator S. In the example shown in FIG. 9, each delivery slip sheet P has nine (9-divided) label bodies R that can be peeled independently from each other on one separator S. Each of the label bodies R is printed to form separate (one set of three) delivery slips.

Thus, since the delivery slip paper P is a label paper, it has a characteristic that it is stiffer than plain paper. In addition, the delivery slip sheet P in which a plurality of label bodies R are attached to a separator S so as to be independently peelable is a friction coefficient (other delivery slip sheets to be laminated) than other portions in each part of the surface. P has a characteristic that there is a portion having a high friction coefficient with P). Specifically, the friction coefficient is higher at the boundary portion between adjacent label bodies R than at other portions. Furthermore, individual differences tend to occur in the characteristics of these delivery slip sheets P.
(2) Operation of Laser Printer 10 In the laser printer 10 having the above-described configuration, the lid member 96 is removed from the paper cassette 86 and opened in a state in which the paper container 62 of the paper supply device 14 is detached from the main body 60. The stacked sheets are stacked (accommodated and supplemented) on the sheet placing plate 88 and the step forming member 90 in the sheet cassette 86 from the opening 86A. After the paper is stored, the lid member 96 is attached to the paper cassette 86, and the paper storage unit 62 (paper cassette 86) is mounted on the main body 60.

  Then, the second arm 80B of the roller holding member 80 is pressed against the paper cassette 86, the nudger roller 68 revolves around the support shaft 70A of the feed roller 70 and moves downward, and the retard roller 72 is below the feed roller 70. Proximity to. Further, the motor 84A is operated in a state where the chuck portion 84B of the placement plate driving portion 84 is engaged with the placement plate vertical mechanism, and the paper placement plate 88 is raised to a predetermined height. As a result, the nudger roller 68 is pressed against the upper surface of the paper (uppermost paper) stacked on the paper placement plate 88.

  When the support shaft 70A of the feed roller 70 is rotationally driven from this state, this driving force is transmitted to the nudger roller 68, and the nudger roller 68 rotates (sends) the delivery slip sheet P in the direction of arrow A. The fed sheet is first brought into contact with the sheet separating pad 94 and then fed between the feed roller 70 and the retard roller 72. As a result, the delivery slip paper P is separated (squeezed) one by one while being discharged from the paper supply device 14 and supplied to the registration rollers 30 of the printer main body 12.

  The delivery slip sheet P is printed on each label body R (that is, one side) with predetermined slip data by the printer main body 12 and discharged onto the discharge tray 44 as a delivery slip (group) for home delivery.

  By the way, as described above, the delivery slip paper P supplied from the paper supply device 14 to the printer main body 12 is stiff and partially has a large coefficient of friction. It may be sent out at once.

  However, as described above, since the step forming member 90 is provided at the front end portion of the sheet placing plate 88, the delivery slip sheet P accommodated in the sheet cassette 86 is lowered by its own waist (elasticity). Therefore, the friction between the upper and lower delivery slip sheets P is reduced, and the lower delivery slip sheet P is prevented from being sent out following the upper delivery slip sheet P. Is done.

  Furthermore, even if the lower delivery slip paper P is sent out following the upper delivery slip paper P, the delivered delivery slip paper P is not displayed as shown in FIG. Also, the leading edge of each sheet is shifted in contact with the sheet-spreading pad 94. Then, only the uppermost sheet to which the conveying force is directly applied by the nudger roller 68 is sandwiched and fed between the feed roller 70 and the retard roller 72. Accordingly, the delivery slip sheet P is not fed multiple times and is stably sent out one by one.

  Further, when the delivery slip sheet P is conveyed by the nudger roller 68 that is arranged offset to the left side, there is a case where the delivery slip sheet P tends to be skewed so that the left side portion is preceded. In this case, as shown in FIG. 8, the delivery slip sheet P has a portion P2 between the rear left corner P1 and the contact portion of the nudger roller 68 with the rear left corner P1 pressed against the left guide wall 92A. Tries to bend so that it swells upward.

  However, since the lid-like member 96 is attached to the upper edge of the paper accommodating portion 62 as described above, the bending portion P2 of the delivery slip paper P contacts the bending deformation regulating portion 100 of the lid-like member 96, Bending deformation is regulated. And since the force which controls this bending deformation resists the force which skews the delivery slip paper P, skewing of the delivery slip paper P itself is suppressed. As a result, the delivery slip sheet P has its skew angle within a range that can be corrected by the registration rollers 30 of the printer main body 12, thereby preventing conveyance failure and printing failure.

  Further, since the guide member 92 is disposed on the upstream side in the sheet conveyance direction with respect to the nudger roller 68 disposed corresponding to the front end portion (front end portion before the start of conveyance) of the delivery slip sheet P, the delivery slip sheet P The left rear corner portion P1 is pressed against the left guide wall 92A in the initial stage of conveyance (skew) and tends to be greatly bent. However, the bending deformation regulation portion 100 restricts the bending deformation of the bending portion P2 of the delivery slip sheet P. Due to the action, the skew of the delivery slip sheet P can be suppressed at the beginning of the conveyance, so that the bending of the left rear corner P1 can be reduced. Further, a measure for arranging the bending deformation restricting portion 100 so as not to interfere with the support shafts 68A and 70A of the roller unit 66 becomes unnecessary, and the structure is simple.

  Further, by offsetting the nudger roller 68 to the left side, the direction in which the delivery slip sheet P is skewed is limited to the direction in which the left side precedes, so that the bending deformation restricting portion 100 offset to the left side corresponding to the nudger roller 68 As described above, the skew of the delivery slip sheet P can be effectively suppressed. That is, the bending deformation restricting unit 100 does not need to be provided symmetrically with respect to the center line along the conveyance direction of the delivery slip sheet P, and suppresses the skew of the delivery slip sheet P without increasing the number or size. Can do.

  As described above, in the paper supply device 14 according to the present embodiment, it is possible to suppress the skew of the paper as it is conveyed. In particular, since the skew of the delivery slip sheet P is also suppressed by the contact between the sheet-spreading pad 94 and the delivery slip sheet P as described above, the sheet feeding device 14 according to the present embodiment is capable of skewing the sheet. Very unlikely to occur.

  Further, here, the lid-like member 96 having the bending deformation restricting portion 100 is configured such that the bending deformation restricting portion 100 faces the delivery slip sheet P while closing a part of the opening 86A of the paper cassette 86, and the opening portion. Since the opening position for opening 86A can be taken selectively, replenishment of the delivery slip sheet P to the sheet cassette 86 is not hindered. In other words, the paper supply device 14 realizes a function of suppressing the skew feeding of the delivery slip sheet P without deteriorating (sacrificing) the replenishability of the delivery slip sheet P. In particular, since the lid-like member 96 is detachable from the paper cassette 86, the function of selectively taking the facing position and the open position is realized with a simple structure. Further, for example, when transporting a type of paper that does not require a lid-like member 96 such as plain paper, the paper deformation restricting member may be removed, or different specifications depending on the type of paper (facing area, facing distance, facing position with the paper) Or the like) is easily mounted.

  Furthermore, since the bending deformation restricting portion 100 is a plate-like member, the paper supply device 14 is lighter and more compact as a whole compared to, for example, a configuration in which the bending deformation restricting portion 100 is formed in a block shape or a roller shape. It is configured. For this reason, the bending deformation restricting portion 100 has a simple structure and can be easily handled (detached from the paper cassette 86 and handled at the manufacturing stage).

  Furthermore, in the above-described embodiment and modification, the bending deformation restricting portion 100 is a preferable configuration that is a plate-like member. However, the present invention is not limited to this, and the bending deformation restricting portion 100 is accompanied by skew. As long as the upward deformation of the sheet can be regulated, it is sufficient, and it is not limited by the shape, size, material, and the like.

  In the first embodiment, the configuration in which the paper supply device 14 has all of the step forming member 90, the paper spreading pad 94, the weight member 82, and the bending deformation restricting portion 100 has been described, but the present invention is not limited to this, for example, Alternatively, any or all of the step forming member 90, the weight member 82, and the bending deformation restricting portion 100 may be omitted. In particular, in a configuration that does not include the step forming member 90, the bending deformation restricting portion 100 may be simply formed flat. In the case of conveying a relatively weak sheet in the configuration having the step forming member 90, the sheet P is difficult to be deformed following the step forming member 90 (the amount of lifting with respect to the lower sheet is small), so that It is preferable to set the gap G between the deformation restricting portion 100 and the upper surface of the sheet to be small.

  Further, in the above-described embodiment and modification, the configuration including the roller unit 66 having the nudger roller 68 as the sheet feeding unit is illustrated. However, the sheet feeding unit in the present invention includes the nudger roller 68 (the roller unit 66). For example, a feed roller 52 provided in the paper feed cassette 50 may be used. Further, instead of providing the roller unit 66 and the feed roller 70 as the paper feeding means, a belt conveyor that contacts the uppermost paper P, that is, a feeding belt conveyor may be provided, and the paper P may be sent out by the feeding belt conveyor. Further, when a delivery belt conveyor is used as the paper delivery means, a retard belt conveyor may be provided opposite to the downstream end of the delivery belt conveyor with the conveyance path of the paper P in place of the retard roller 72. .

  In the above embodiment, the paper supply device 14 supplies the delivery slip paper P, which is a label paper, to the printer main body 12. However, the present invention is not limited to this, and the paper supply device 14 is not limited thereto. May be supplied to the printer main body 12. In particular, the paper supply device 14 is suitably applied to transport and supply of paper that is stiffer and has a larger coefficient of friction (including electrostatic friction) than plain paper. The paper in the present invention may be a sheet-like member on which an image is formed by the image forming apparatus, and is not limited to paper. Therefore, for example, the paper supply device 14 can be applied to continuous supply of a transparent plastic sheet such as an OHP sheet.

  In addition to laser printers, the present invention can be applied to various printers such as dot impact printers, inkjet printers, heat-melting thermal transfer printers, sublimation thermal transfer printers, thermal printers, and various copying machines.

FIG. 1 is a schematic side sectional view showing a schematic overall configuration of an example of a laser printer having a paper supply device according to an embodiment of the present invention. FIG. 2 is a perspective view showing a schematic overall configuration of the paper supply device provided in the laser printer shown in FIG. FIG. 3 is a plan view showing the internal structure of the paper supply apparatus shown in FIG. FIG. 4 is a side view showing a main part of the paper supply apparatus shown in FIG. FIG. 5 is a side view for explaining the function of the step forming member of the paper supply apparatus shown in FIG. FIG. 6 is a side view for explaining the function of the paper spreading pad provided in the paper supply device shown in FIG. FIG. 7 is an explanatory diagram of an angle formed by the sheet contact surface of the sheet separating pad included in the sheet supply device illustrated in FIG. 2 and the sheet. FIG. 8 is a schematic plan view showing a state in which the paper is skewed in the conveyance process by the paper supply device shown in FIG. FIG. 9 is a perspective view of a delivery slip sheet conveyed by the sheet supply apparatus shown in FIG. FIG. 10 is a schematic diagram showing the configuration of a conventional paper supply apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Laser printer 12 Printer main body 14 Paper supply apparatus 15 2004 Housing 18 Image processing part 20 Image output part 22 Photosensitive drum 24 Charging apparatus 26 Optical scanning apparatus 28 Development apparatus 30 Registration roller 32 Transfer apparatus 34 Separation charging apparatus 36 Fixing apparatus 38 Cleaning Device 40 Process cartridge 41 Discharge transport path 44 Discharge tray 46 Double-side transport unit 50 Paper feed cassette 51 Paper feed transport path 52 Feed roller 53 Paper feed transport path 54 Transport roller 56 Tray 58 Paper feed roller 60 Main body 60 Main body 62 Paper storage portion 63 Paper feed conveyance path 64 Housing 66 Roller unit 68 Nudger roller 70 Feed roller 72 Retard roller 78 Front frame 82 Weight member 84 Placement plate drive portion 86 Paper cassette 88A Front end portion 88 Paper placement plate 90 Step forming member 92 Guide member 94 Paper spreading pad 96 Lid member 98 Mounting portion 100 Bending deformation restricting portion 100A Rear end portion 100B Front end portion 1000 Laser printer

Claims (8)

A paper storage unit for storing paper supplied to the image forming means;
A paper feeding means for holding the paper and transporting it toward the image forming means along a predetermined transport path while contacting the paper positioned at the top of the paper stored in the paper storage section;
A paper spreading pad formed with a paper contact surface that contacts the paper so as to incline upward along the transport path upstream of a position where the paper is sandwiched in the paper delivery means; A paper supply device comprising:   The sheet feeding means includes at least one nudger roller provided so as to contact the uppermost sheet among the sheets accommodated in the sheet accommodating portion, and downstream of the nudger roller along the sheet conveyance path. And at least one retard roller positioned on the opposite side of the feed roller across the transport path, and the feed roller and the retard roller are transported by the nudger roller. The sheet-spreading pad has the sheet contact surface on the upstream side of the position where the sheet is sandwiched between the feed roller and the retard roller. The paper supply device according to claim 1, wherein the paper supply device is provided so as to be positioned.   3. The paper supply device according to claim 1, wherein the paper spreading pad has a coefficient of dynamic friction between the paper contact surface and the paper of 0.5 to 1. 3.   The paper spreading pad is disposed so that an angle between the paper contact surface and the uppermost paper is in a range of 140 to 160 degrees when the paper is stored in the paper storage portion. The paper supply device according to any one of claims 1 to 3.   The paper supply device according to any one of claims 1 to 4, wherein the paper spreading pad is formed of a foamed elastomer.   An image forming apparatus comprising: the sheet supply device according to claim 1; and an image forming unit that forms an image on the sheet supplied from the sheet supply device.   The image forming apparatus according to claim 6, wherein the image forming unit is an electrophotographic image forming unit.   The image forming apparatus according to claim 6, wherein the sheet is a label sheet including a label body having an image forming surface on which an image is formed, and a separator to which the label body is detachably attached.

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