JP5264425B2 - Curl holding member, sheet package, sheet feeding apparatus, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curling preventive member pressing curling of a loaded sheet with a simple structure without imparting damage to the sheet, and also to provide a sheet package, a sheet feeding device, and an image forming device. <P>SOLUTION: This sheet-like curling pressing member 11 is mounted on an upper face of the sheet S loaded in a paper feeding tray 1 to press the curling of the sheet S. When the sheet S loaded in the paper feeding tray 1 is fed by a paper feeding roller 5, moving of the curling pressing member 11 accompanying feeding of the sheet S by the paper feeding roller 5 is regulated by a moving regulation part 30. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a technique for preventing warping (curling) of a sheet of recording paper or the like stored in an image forming apparatus such as a printer, a copying machine, or a printing machine.

  2. Description of the Related Art Today, image forming apparatuses such as printers and copiers are widely used in which an image is formed by feeding a sheet to an image forming unit. In general, such an image forming apparatus includes a sheet feeding apparatus that feeds sheets stacked in a sheet feeding cassette to an image forming unit using a sheet feeding member.

  FIG. 9 is a sectional view of such a conventional sheet feeding apparatus. In FIG. 9, reference numeral 1 denotes a paper feed tray for storing sheets S, and an intermediate plate 2 on which the sheets S are stacked is provided on the paper feed tray 1 so as to be lifted and lowered. The intermediate plate 2 is biased upward by the intermediate plate spring 4, whereby the uppermost sheet S 1 of the sheets S stacked on the intermediate plate 2 is pressed against the paper feed roller 5.

  Then, when the uppermost sheet S1 is pressed in this manner, the sheet feeding roller 5 rotates in the direction of the arrow, whereby the uppermost sheet S1 is fed. The separation pad 6 is in pressure contact with the paper feed roller 5 and when two or more sheets S are to be fed, the second and subsequent sheets are stopped by the separation pad 6, whereby the sheet weight is reduced. Sending is prevented.

  FIG. 10 is a view taken in the direction of arrow A of the sheet feeding apparatus. As shown in FIG. 10A, the sheet S is placed at both ends of the sheet feeding tray 1 in the width direction orthogonal to the sheet feeding direction. Width regulating guides 7 and 8 are provided for regulating the position in the width direction. When the sheet is fed, the sheet S is fed while its both ends are regulated by the width regulation guides 7 and 8, and therefore the sheet S is fed toward the image forming unit without being skewed.

  By the way, curled sheets S such as label sheets at low temperatures and sheets left for a long time at high temperatures are stacked on the intermediate plate 2 on the sheet feed tray 1 having such width regulation guides 7 and 8. There is a case. Here, when the sheet to be stacked is, for example, a sheet that is greatly curled upward (in a bowl shape), both ends of the sheet S get over the width regulation guides 7 and 8 as shown in FIG. For this reason, it is impossible to regulate both side edges of the sheet S.

  When the sheet S is fed by rotating the sheet feeding roller 5 in this state, the sheet S is skewed and a problem such as jam (paper jam) occurs. Further, for example, when the sheet feeding tray 1 on which the sheets S are stacked is not attached to the image forming apparatus main body and left in a high temperature environment, the curling of the sheet S becomes large and protrudes upward from the sheet feeding tray 1. In this case, when the paper feed tray 1 is to be mounted on the image forming apparatus main body, there is a problem that the protruding sheet S hits the image forming apparatus main body and damages the sheet.

  Therefore, in order to prevent the sheet S from getting over and protruding when the curled sheets are stacked on the intermediate plate, there has conventionally been provided a curl pressing member that presses both ends of the sheet from above (Patent Document). 1).

  FIG. 11 is a diagram showing the configuration of such a conventional paper feed cassette. In FIG. 11, reference numerals 9 and 10 denote curl pressing members provided on the width regulation guides 7 and 8 of the paper feed tray 1. When the curled sheet S is stacked on the middle plate, the curl of the sheet S is pressed by the curl pressing members 9 and 10.

JP 2001-88970 A

  However, in the conventional sheet feeding apparatus and the image forming apparatus including the same, when such a curl pressing member is provided in the sheet feeding cassette, the structure becomes complicated and the cost is increased.

  Further, in the case where the middle plate is lowered when the paper feed cassette is not attached to the image forming apparatus main body and is raised after the paper feed cassette is attached to the image forming apparatus main body, until the paper feed cassette is attached. During this period, the intermediate plate is lowered. When the intermediate plate is lowered as described above, for example, when the number of sheets stacked in the sheet feeding cassette is small, the curled sheet does not come into contact with the curl pressing member, so the curl pressing member presses the curl. I can't.

  If the sheet is label paper, the sheet will start to curl immediately after the sheet package is unpacked and immediately after the sheet is stacked on the middle plate. Cheap.

  Therefore, the present invention has been made in view of such a current situation, and has a simple structure, and a sheet feeding apparatus and an image forming apparatus that can suppress the curling of the sheets without damaging the stacked sheets. Is intended to provide. It is another object of the present invention to provide a curl pressing member and a sheet package that can press the curl of a sheet with a simple structure without damaging the stacked sheets.

The present invention provides a sheet feeding device that feeds a sheet stacked on a sheet stacking unit and whose position is regulated by a regulating member by a sheet feeding member, and is placed on an upper surface of the sheet stacked on the sheet stacking unit. comprises Luca Lumpur pressing member pressing the sheet curl, said curl pressing member has a plurality of provided the sheet feeding member along a first notch portion and the sheet feeding direction for contacting the sheet A first sheet member formed with a to-be-latched portion, a second notch portion for bringing the sheet feeding member into contact with the sheet, and the plurality of to-be-latched portions of the first sheet member selectively. And a second sheet member formed with an engaging part that engages with the restricting member, and when pressing a sheet of a predetermined size, the first notch part and the second sheet member Match the second notch The locking portion is locked to the locked portion on the downstream side in the sheet feeding direction of the plurality of locked portions, and the first sheet member and the second sheet member are connected so as to overlap each other. When pressing a sheet having a larger size, the first sheet member and the second sheet are obtained by locking the locking portions to the locked portions on the upstream side of the plurality of locked portions in the sheet feeding direction. The members are connected so as to be connected, and the engaging portion is engaged with the regulating member by engaging the first sheet member and the second sheet member, which are engaged by engaging the engaging portion with the engaged portion. Therefore, the movement on the upper surface of the sheet is restricted .

  By mounting the curl pressing member on the upper surface of the sheets stacked on the sheet stacking portion as in the present invention, the curl of the sheets can be pressed without damaging the stacked sheets with a simple structure. .

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram illustrating a schematic configuration of a printer which is an example of an image forming apparatus including a sheet feeding device according to a reference example of the invention.

  In FIG. 1, 50 is a printer, 51 is a printer main body which is an apparatus main body, 52 is provided in the printer main body 51, and forms an image by an electrophotographic method, and 54 feeds a sheet S to the image forming section 52. This is a sheet feeding device.

  Here, the image forming unit 52 includes a photosensitive drum 53 that forms a toner image, a transfer roller 15 that transfers the toner image formed on the photosensitive drum 53 to the sheet S, and the like. In the image forming section 52 having such a configuration, when an image forming operation is started, first, light corresponding to an image signal is irradiated to the photosensitive drum 53 from a laser exposure device (not shown). Then, by irradiating light according to such an image signal, a latent image is formed on the photosensitive drum. Next, the latent image on the photosensitive drum is developed with the toner supplied by the developing means and visualized as a toner image.

  The sheet feeding device 54 is detachably attached to the printer main body 51 and is a sheet feeding tray 1 that is a sheet stacking unit for stacking sheets, and a sheet feeding member that feeds sheets S stored in the sheet feeding tray 1. The paper feed roller 5 is provided. Here, the sheet feeding tray 1 regulates the middle plate 2 that can rotate in the vertical direction on which the sheets S are stacked, and the positions of both ends in the width direction perpendicular to the sheet feeding direction of the sheets S, which will be described later. And a rear end regulating member 12 that regulates the rear end of the sheet S.

  Further, a separation pad 6 that is pressed against the paper feed roller 5 is provided on the downstream side of the paper feed tray 1 in the sheet feeding direction. The separation pad 6 is pressed against the paper feed roller 5 by a separation pad spring 6a. It has become. In such a sheet feeding device 54, when an image is formed, the sheet S is fed from the sheet feeding tray 1 by the sheet feeding roller 5, and thereafter, the sheet S is pressed against the sheet feeding roller 5 and separated. The pads 6 are separated one by one.

  Next, an image forming operation in the printer 50 having such a configuration will be described.

  When a print start signal is input, the sheet S stacked on the sheet feeding tray 1 is sent out by friction with the sheet feeding roller 5, and thereafter, the sheet S is urged by the separation pad spring 6a and fed to the sheet feeding roller. The sheets are separated one by one by a separation pad 6 in pressure contact with 5 and fed.

  Next, the sheet S is conveyed by the conveying roller 13 to reach the registration roller pair 14, and the leading edge of the sheet S is aligned by the registration roller pair 14. If the photo sensor (not shown) detects the passage of the sheet S before reaching the registration roller pair 14, the laser exposure device (not shown) irradiates the photosensitive drum 53 with laser light.

  Thereby, an electrostatic latent image is formed on the photosensitive drum, and the electrostatic latent image is visualized by developing the electrostatic latent image with toner. Thereafter, the visualized toner image on the photosensitive drum is transferred to the sheet S by applying a voltage having a polarity opposite to that of the toner image formed on the photosensitive drum 53 to the transfer roller 15.

  Next, the sheet S to which the toner image has been transferred is conveyed to the fixing unit 16 and is pressurized and heated when passing through the fixing unit 16 so that the toner image is permanently fixed on the sheet. Then, the sheet S on which the toner image is fixed is stacked on the paper discharge tray 55 by the paper discharge roller pairs 17-19.

  In FIG. 1, reference numeral 11 denotes a sheet-like curl pressing member placed on the upper surface of the sheet S stacked on the sheet feeding tray 1. This curling pressing member 11 is substantially the same as the sheet S to be fed. It has a shape.

  When the sheet S to be stacked and stored in the paper feed tray 1 is, for example, label paper that starts to curl immediately after being stacked on the middle plate 2, the curl pressing member is used when the sheets are stacked and stored in the paper feed tray 1. 11 is placed on the stacked sheet S. Thus, by placing the curl pressing member 11 on the sheet S, the curl of the sheet S can be pressed. Thus, after that, when the paper feed tray 1 is detachably attached to the printer main body 51, the paper feed tray 1 can be attached without the sheet S being caught.

  The curl pressing member 11 is prevented from coming into contact with the paper feed roller 5 as shown in FIG. 2, for example, in order to avoid being fed by the paper feed roller 5 when placed on the sheet. A notch 11a or an opening (not shown) is formed. As described above, the curl holding member 11 has the notch 11 a for bringing the paper feed roller 5 into contact with the sheet at a position facing the paper feed roller 5. In addition, an opening portion 11 b larger than the rear end regulating member 12 that regulates the rear end position on the upstream side in the sheet feeding direction of the sheet S is formed at the rear end portion of the curl holding member 11.

In this reference example , the sheet feeding roller 5 feeds the sheet by the rear end regulating member 12 of the sheet feeding tray 1 serving as the stopper and the opening 11b of the curl pressing member 11 serving as the engaging portion. A movement restricting portion 30 that restricts the movement of the accompanying curl pressing member 11 is configured.

  When the curl pressing member 11 is placed on the sheet, the curl pressing member 11 is passed through the opening 11b through the trailing end regulating member 12 and the side edge regulation for regulating the sheet width direction position of the sheet feeding tray 1 is performed. It is made to mount between the width control guides 7 and 8 which are members. As a result, the curl pressing member 11 and the rear end regulating member 12 can be engaged. By providing such a notch 11a and opening 11b, even when the curl pressing member 11 is placed on the sheet, the curl pressing member 11 is fed and fed by the sheet S immediately below it. Can be prevented.

  Further, in order to avoid feeding by the paper feed roller 5, for example, as shown in FIG. 3, the curl holding member 11 is provided in the width direction at the upstream end of the sheet feeding direction, that is, at the rear end. The protrusions 11c and 11d may be formed. The distance in the width direction between the two protrusions 11c and 11d is longer than the width of the sheet S.

  When such a curl pressing member 11 is placed on the sheet, the curl pressing member 11 is placed so as to be engaged with the protrusions 11c and 11d and the rear end portions of the width regulating guides 7 and 8. To do. As a result, the curl pressing member 11 can be prevented from being fed by feeding the sheet S immediately below it.

  That is, in this case, the movement restricting portion 30 is configured by the width restricting guides 7 and 8 (rear end portions) that are stopper portions and the protruding portions 11c and 11d of the curl pressing member 11 that is an engaging portion. If the curl holding member 11 can be engaged with the width regulating guides 7 and 8, the curl holding member 11 is against the stopper portion provided in the region that does not overlap the sheet stacked in the sheet feeding cassette. A protrusion or a hole that can be engaged may be formed.

By the way, if the curl holding member 11 is too light, the curl of the sheet S cannot be pressed, and if the curl holding member 11 is too heavy, the sheet S cannot be fed and a feeding failure occurs. For this reason, in this reference example , the weight of the curl pressing member is set according to the curl amount of the sheet S.

FIG. 4A is a diagram showing the relationship between the weight of the curl pressing member 11 obtained by the experiment and the curl pressing amount (correction amount), and FIG. 4B is the curl pressing member 11 obtained by the experiment. It is a figure which shows the relationship between the weight and non-feeding. 4A and 4B show the relationship when the basis weight is about 170 gf / mm ² , A4 size label paper, and the curl amount is 55 mm.

  Here, it can be seen from FIG. 4A that the curl holding member 11 needs to have a weight of about 30 gf in order to reduce the curl amount to 10 mm or less. Also, from FIG. 4B, it can be seen that the non-feeding occurs when the weight of the curl pressing member 11 exceeds 50 gf. Therefore, it can be seen from FIGS. 4A and 4B that the weight of the curl pressing member 11 under the above-described conditions is reasonable from 30 gf to 50 gf.

  As described above, by placing the curl pressing member 11 on the upper surface of the sheet S stacked on the sheet feeding tray 1, the curling of the sheet can be suppressed, and even when the intermediate plate 2 is lowered, the sheet Curling can be prevented in advance. Further, even for label paper at low temperatures and sheets left for a long time at high temperatures, the curling of the sheets can be suppressed before the paper feed tray 1 is mounted on the printer main body 51, causing skew and jamming. Sheets can be fed without Further, when the sheets stacked on the sheet feeding tray 1 are fed by the movement regulating unit 30, the movement of the curl pressing member 11 accompanying the feeding of the sheets can be regulated.

  Accordingly, it is possible to provide the sheet feeding device 54 and the printer 50 (image forming apparatus) that can suppress the curling of the sheets with a simple structure without damaging the stacked sheets.

Next, a description will be given implementation of the present invention.

  FIG. 5 is a diagram illustrating the configuration of the curl pressing member used in the sheet feeding apparatus according to the present embodiment. In FIG. 5, reference numeral 20 denotes a curl pressing member for an A3 size sheet. The curl pressing member 20 is formed by assembling two (a plurality of) sheet members 20a and 20b.

  Here, as shown in FIG. 6A, the first sheet member 20a of the two sheet members 20a and 20b has a first cut so as not to contact the sheet feeding roller 5. A notch 21a is formed. Further, a second notch 21b is formed in the first sheet member 20a so as not to contact the rear end regulating member 12. Further, the first sheet member 20a includes first and second engagement openings 23a and 23b formed on the downstream side in the sheet feeding direction, and third and fourth engagements formed on the upstream side in the sheet feeding direction. Joint openings 24a and 24b are formed.

  Further, as shown in FIG. 6B, a cutout 21c is formed in the other second curl pressing member 20b so as not to contact the paper feed roller 5. Further, the second curl pressing member 20b is formed with an opening 21d and first and second engaging protrusions 22a and 22b so as not to contact the rear end regulating member 12.

  When the A3 size sheet is pressed, the first and second engaging protrusions 22a and 22b of the second curl pressing member 20b and the third and fourth engaging openings 24a and 24b of the first sheet member 20a. Are elastically engaged with each other as shown in FIG. Then, by assembling the first and second sheet members 20a and 20b in this way, the curl pressing member 20 for an A3 size sheet is formed.

  As shown in FIG. 7, the first and second engagement protrusions 22a and 22b of the second curl pressing member 20b and the first and second engagement openings 23a and 23b of the first sheet member 20a are engaged with each other. The first and second sheet members 20a and 20b can be assembled together. Then, by assembling the first and second sheet members 20a and 20b in this way, the curl pressing member 20A for an A4 size sheet can be formed.

  In this way, the first and second engagement protrusions 22a and 22b of the second curl pressing member 20b are selectively used as the first to fourth engagement openings 23a, 23b, 24a and 24b of the first sheet member 20a. By engaging, the shape of the curl pressing member 20 can be changed. In other words, the curl pressing member 20 is formed by the two sheet members 20a and 20b, and the combination of the two sheet members 20a and 20b is changed, whereby the curl pressing member 20 having a different shape can be obtained. Then, by allowing the shape of the curl pressing member 20 to be changed in this way, the shape of the curl pressing member 20 can be made to be a shape corresponding to the size of the sheets stacked on the paper feed tray 1.

  By the way, as described above, when the sheet S is a label sheet or the like, curling starts to occur immediately after the sheet package is unpacked and stacked on the intermediate plate 2. Therefore, in order to prevent the occurrence of curling of the sheet, when the sheet S such as label paper is packed as the sheet package P as shown in FIG. 8, the curl holding member 11 is placed on the upper surface of the sheet S. Pack it with. As a result, after unpacking the sheet package P, the user can stack the sheet S and the curl pressing member 11 together on the intermediate plate 2 and prevent the sheet from curling. Further, even when the sheet package P is unpacked and the sheet S is stacked on the intermediate plate 2 before the sheet S is stacked, the curling of the sheet can be prevented.

FIG. 2 is a diagram illustrating a schematic configuration of a printer that is an example of an image forming apparatus including a sheet feeding device according to a reference example of the invention. FIG. 4 is a diagram illustrating a configuration of a curl pressing member that presses a curl of sheets stacked on a sheet feeding tray provided in the sheet feeding apparatus. The figure explaining the other structure of the said curl pressing member. (A) is a chart showing the relationship between the weight of the curl pressing member and the curl pressing amount (correction amount), and (b) is a chart showing the relationship between the weight of the curling pressing member and non-feeding. It illustrates a structure of the curl pressing member used in a sheet feeding apparatus according to implementation of the embodiment of the present invention. The figure explaining the structure of the 1st and 2nd curl pressing member which forms the said curl pressing member. The figure which shows the other assembly methods of the said 1st and 2nd curl pressing member. The figure explaining the sheet package which packed the said curl pressing member with the sheet | seat. Sectional drawing of the conventional sheet feeding apparatus. A direction arrow view of the conventional sheet feeding apparatus. The figure which shows the structure of the conventional paper feed cassette.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feed tray 2 Middle plate 5 Paper feed roller 7, 8 Width control guide 11 Curl presser member 11a Notch 11b Opening part 11c, 11d Projection part 12 Rear end control member 20, 20A Curl presser member 20a, 20b Sheet member 21a First 1 notch 21b second notch 21c notch 21d opening 22a, 22b first and second engaging projections 23a, 23b first and second engaging openings 24a, 24b third and fourth engaging openings Section 30 Movement restriction section 50 Printer 51 Printer main body 52 Image forming section 54 Sheet feeding device P Sheet package S Sheet

Claims (6)

In a sheet feeding device that feeds a sheet stacked on a sheet stacking unit and whose position is regulated by a regulating member by a sheet feeding member,
Wherein is placed on the upper surface of the stacked sheets on the sheet stacking portion includes a Luca Lumpur pressing member pressing the sheet curl,
The curl pressing member includes a first sheet member in which a first notch for bringing the sheet feeding member into contact with a sheet and a plurality of locked portions provided along the sheet feeding direction; The sheet feeding member engages with a second notch portion for contacting the sheet, a locking portion selectively locked with the plurality of locked portions of the first sheet member, and the regulating member. A second sheet member formed with an engagement portion,
When pressing a sheet of a predetermined size, the engagement is performed on the locked portion on the downstream side in the sheet feeding direction of the plurality of locked portions so that the first cutout portion and the second cutout portion coincide with each other. When the sheet is connected to the first sheet member and the second sheet member so that the first sheet member and the second sheet member overlap with each other, and a sheet having a size larger than a predetermined size is pressed, the sheet feeding of the plurality of locked parts is performed. The locking portion is locked to the locked portion on the upstream side in the direction so that the first sheet member and the second sheet member are connected, and the locking portion is locked to the locked portion. The sheet feeding device is characterized in that movement of the first sheet member and the second sheet member connected in this manner is restricted by engaging the engaging portion with the restricting member . The regulating member is a trailing end regulating member that regulates the trailing end position on the upstream side in the sheet feeding direction of the sheet,
Wherein the engaging portion of the second sheet member, the time of placing the curl pressing member, a sheet feeding apparatus according to claim 1, characterized in that an opening that engages the trailing edge regulating member. The regulating member is a side end regulating member that regulates the position in the width direction orthogonal to the sheet feeding direction of the sheet,
Wherein the engaging portion of the second sheet member, the formed on the side edge of the curl pressing member, the side edge regulating member and the sheet feeding apparatus according to claim 1, characterized in that the projections which engage . Imaging, wherein an image forming unit for forming an image on a sheet, that and a device sheet feeding according to any one of claims 1 to 3 for feeding sheets to the image forming section apparatus. Stacked on the sheet stacking portion provided in the sheet feeding apparatus is placed on the upper surface of the sheet fed by the sheet feeding member in a state in which the position is regulated by the regulating member curled to obtain curling of the push of the sheet A holding member,
A first sheet member formed with a first notch for bringing the sheet feeding member into contact with the sheet and a plurality of locked portions provided along the sheet feeding direction;
The sheet feeding member engages with a second notch portion for contacting the sheet, a locking portion selectively locked with the plurality of locked portions of the first sheet member, and the regulating member. A second sheet member formed with an engagement portion,
When pressing a sheet of a predetermined size, the engagement is performed on the locked portion on the downstream side in the sheet feeding direction of the plurality of locked portions so that the first cutout portion and the second cutout portion coincide with each other. When the sheet is connected to the first sheet member and the second sheet member so that the first sheet member and the second sheet member overlap with each other, and a sheet having a size larger than a predetermined size is pressed, the sheet feeding of the plurality of locked parts is performed. The locking portion is locked to the locked portion on the upstream side in the direction so that the first sheet member and the second sheet member are connected, and the locking portion is locked to the locked portion. A curl pressing member that restricts movement of the first sheet member and the second sheet member that are connected together by engaging the engaging portion with the restricting member, on the upper surface of the sheet . A sheet package in which a plurality of sheets are packed,
A sheet package comprising a plurality of sheets and the curl pressing member according to claim 5 .

Images