JP4840209B2 - Paper cassette - Google Patents

Description

  The present invention relates to a paper cassette for recording paper that is detachably attached to an image forming apparatus such as a copying machine, a facsimile machine, a printer, or a so-called multifunction machine having these functions.

The image forming apparatus includes an image recording unit, and recording paper is supplied to the image recording unit as needed to record an image based on image information. The recording paper is accumulated in a paper feeding cassette that is detachably mounted in the image forming apparatus, and is conveyed and supplied to the recording unit one by one by the operation of the separation paper feeding device and the conveying device. The recording paper deposited in the paper cassette is urged upward by a paper push-up plate installed in the paper cassette body case so that the leading end of the uppermost layer is always in elastic contact with the separation paper feeder. ing. The paper push-up plate is pivotally supported in the main body case, and the tip side thereof is in an upward biased state by an elastic member such as a compression spring. A paper width regulating width guide member and a paper trailing edge regulating end guide member are installed on the side of the paper push-up plate and on the rear side in the paper feeding direction (see Patent Document 1).
JP 2003-137445 A

  The dimensions of the recording paper set and deposited in the paper feed cassette as described above vary depending on the surrounding environment and cutting errors. Therefore, an elastic member such as sponge is attached to the inner surface (the surface in contact with the recording paper) of the width guide member and the end guide member so as to absorb the variation in the above dimensions. By the way, when a recording sheet larger than a prescribed size is set, the stiffness of the recording sheet is lost by the elastic force of the elastic member and is bent in the cassette. When the width guide member causes such bending in the width direction, it causes skewing in the subsequent sheet conveyance process. Also, if the elastic force of the elastic member is weak, the guide function when the paper is full will not be sufficiently exerted, and if the elastic force is strong, the recording paper will be pushed too much when the number of recording paper sheets is reduced. In particular, in the case of the width guide member, the accumulated recording paper is always urged upward by the recording paper push-up plate, and as the recording paper decreases, the side portion of the accumulated recording paper moves upward while slidingly contacting the width guide member. Then, the accumulated recording paper that has decreased is subjected to the elastic regulation of the elastic member at the upper portion of the width guide member, and the recording paper is bent in the width direction by this elastic force, and the skew is more likely to occur.

  Patent Document 1 discloses that the lower part of the elastic force of the elastic member provided on the end guide member is smaller than the upper part. In this way, by reducing the elastic force of the elastic member of the end guide member in the lower part, the recording paper can be reliably and smoothly fed from the paper feeding cassette regardless of the amount of the accumulated paper, and skew feeding and paper Clogging can be effectively prevented. However, Patent Document 1 focuses on the bending of the end guide member due to the amount of recording paper, but does not refer to the bending of the width guide member in the width direction due to the amount of recording paper. In particular, in the case of the upper-layer recording paper in a full-paper state, the strength of the stiffness to which the accumulated weight is added is smaller than that of the lower-layer portion, that is, the elastic force received from the elastic member of the width guide member is the accumulated weight of the recording paper. Therefore, the upper layer paper may bend in the width direction by the elastic force of the elastic member even when the paper is full, depending on the setting of the elastic force of the elastic member. Moreover, due to the upward movement of the push-up plate accompanying the decrease in the accumulated recording paper, the lower-layer recording paper slides on the width guide member and moves upward. During this movement, the stiffness of the accumulated recording paper gradually decreases. The end guide member in Patent Document 1 does not correspond to the behavior of the recording paper on the push-up plate.

  The present invention has been made in view of the above circumstances, and regardless of the change in the amount of recording paper deposited on the paper push-up plate, due to the change in elastic force received from the elastic member provided in the width guide member, An object of the present invention is to provide a paper feed cassette capable of preventing the occurrence of bending of the recording paper in the width direction.

The sheet cassette according to the present invention includes a main body case for accumulating and storing a large number of sheets, a sheet push-up plate pivotally supported in the main body case so as to swing up and down, and an urging force for upwardly pushing the sheet push-up plate. A paper feed cassette comprising a biasing means and a paper width regulating width guide member installed on a side of the paper push-up plate, wherein the width guide member includes a regulation board, and the side of the recording paper of the regulation board is It is an inclined surface, and an elastic member having a uniform thickness is attached to the inclined surface, and the upper portion of the elastic member is set so that the elastic force is weakened by reducing the degree of compression. .

  In the present invention, the magnitude of the elastic force in the vertical direction of the elastic member can be set based on a difference in the shape of the elastic member or on a difference in the material of the elastic member. As the elastic member, a resin or rubber foam (sponge), a combination of a foam and a film, or the like is employed. In this case, as an example of setting the magnitude of the elastic force in the vertical direction depending on the shape of the elastic member, it is effective to make the compression thickness different or the width different from each other in the same foam. . In addition, as an example of setting the magnitude of the elastic force in the vertical direction depending on the material of the elastic member, the foaming magnification of the foam may be different up and down, the upper side is only the film, and the lower side is the foam and the film. It is effective to combine them.

  According to the paper feed cassette of the present invention, the width of the sheets stacked and accommodated in the main body case is regulated by the width guide member, and the end portions in the width direction are aligned. Since the width guide member is provided with an elastic member on the side in contact with the stacked paper, variations in width due to the surrounding environment and cutting errors are absorbed by the elastic member, and the paper width alignment function is exhibited. In this case, since the elastic force of the elastic member is set to gradually weaken from the lower part to the upper part, the elastic force is applied to the lower part of the accumulated paper regardless of the stiffness of the sheet to which the accumulated weight is added. However, the lower width of the elastic member, which is set to be strong, can fully exhibit the sheet width alignment function without deterioration. In addition, in the upper part of the accumulated paper, the stiffness of the paper to which the accumulated weight is added is reduced. However, since the elastic force of the upper elastic member is set to be weak, the paper that has received this elastic force The width is aligned without causing bending in the width direction. When the accumulation amount is reduced as the accumulation paper is fed out, the stiffness of the paper to which the accumulation weight of the paper of each layer is added also decreases. The stacked paper is moved up by the urged paper push-up plate, and the sliding contact position of the paper width edge with the elastic member moves upward, so that the elasticity acting on the paper from the width direction as the stiffness of the paper decreases. The force is also weakened, and the width aligning function is maintained without causing bending in the width direction in the process of paper reduction. Therefore, stable and smooth sheet feeding without skew can be realized.

  If the elastic force in the vertical direction of the elastic member is set based on the difference in the shape of the elastic member or the difference in the material of the elastic member, the setting is simple and increases the cost. It is lost and extremely beneficial.

The best mode for carrying out the present invention will be described below with reference to the drawings. 1 is a schematic perspective view of an image forming apparatus using a paper feed cassette of the present invention, FIG. 2 is a schematic perspective view showing an embodiment of the paper feed cassette, and FIG. 3 is a plan view of the paper feed cassette. 4 is an enlarged sectional view taken along line XX in FIG. 3, FIG. 5 is a view similar to FIG. 4 showing a state in which the amount of recording paper deposited in the paper feed cassette of the embodiment is reduced, and FIG. 6 is a reference example. width guide schematic perspective view of a member of the, 7 and 8 are similar views to FIG. 4 showing a reference example by example.

  The image forming apparatus A in FIG. 1 shows a so-called multi-function machine having a copying function, a facsimile function, and a printer function, but it may be a dedicated machine for these functions. The image forming apparatus A in FIG. 1 is configured in a state in which an image reading unit 1, an image recording unit 2, and a recording paper (sheet) paper feeding unit 3 are stacked in this order from above. The image reading unit 1 includes a reading device casing 1a that houses an optical image scanning reading device (not shown), and a document pressing plate 1b that is mounted on the reading device casing 1a so as to be openable and closable. . On the upper surface of the document pressing plate 1b, a document supply tray 1c for automatic document feeding (ADF) and an ADF document discharge tray 1d are provided so as to overlap each other. The reading device casing 1a includes an ADF reading unit (not shown) that reads image information of a document sent by ADF while the image scanning reading device is stationary, and the image scanning reading device is flat on the upper surface of the reading device casing 1a. It comprises an FBS reading unit (not shown) that scans the image information of the document by scanning the document placed on the bed unit (not shown). An operation panel 1e for operating each function of the image forming apparatus A is formed on one side of the reading apparatus housing 1a. The forming part of the operation panel 1e is connected to the front side of the image forming apparatus A. Is done.

  The image recording unit 2 includes a recording device of an electrophotographic system and a recording paper transport device (both not shown) in the recording unit housing 2a, and the recording paper fed out from the paper feeding unit 3 one by one. In addition, an image is recorded based on the input image information. The recording paper on which the image has been recorded is sequentially discharged and deposited on a recording paper discharge portion 2b formed between the upper surface of the recording portion housing 2a and the lower surface of the reading device housing 1a.

  Next, the paper feed cassette according to the present invention will be described. The recording paper feeding unit 3 in the image forming apparatus A shown in FIG. 1 includes the two-stage recording paper feeding cassettes 4 and 4, but is configured so that the number of stages can be further increased as an optional unit. Is also possible. These paper feed cassettes 4 can be inserted / removed from the front side of the image forming apparatus A (so-called front loading), thereby saving the space of the apparatus. As shown in FIGS. 2 and 3, the paper feed cassette 4 includes a paper push-up plate (flapper) 5 that is pivotally supported in a vertically swingable manner in a body case 4 a having an open top surface, and the paper push-up plate 5. And a compression coil spring (biasing means) 6 that urges the paper upward, and a paper casing push-up plate 5 that is rotatably supported by the main body case 4a on the front side of the paper push-up plate 5 (recording paper feed direction side, which will be described later). The sheet feeding roller 7, an end guide member 8 that regulates the trailing edge of the paper, and paper width regulating width guide members 9 and 10 installed on both sides of the flapper 5 are configured. The separation paper feed roller 7 feeds and feeds one sheet at a time from the uppermost layer paper of the accumulated recording paper by a cooperative action with a separation pad (not shown) installed at a corresponding position of the main body case 4a. As the recording paper separating and feeding device, a separation claw method can also be adopted.

A grip portion 4b is formed on the front side of the main body case 4a in the paper feed cassette 4 and can be inserted and removed from the front side of the image forming apparatus A along the white arrow a direction in FIGS. . The flapper 5 is pivotally supported by the main body case 4a through a pivot pin 5a at the base, and the tip side of the flapper 5 can swing up and down with the pivot pin 5a as a fulcrum. The compression coil spring 6 is elastically mounted between the bottom surface of the main body case 4 a and the front lower surface of the flapper 5, and an upward biasing force is applied to the front side of the flapper 5. The recording paper P (see FIG. 3) is stacked and set in the main body case 4a so as to push down the flapper 5 against the urging force of the compression coil spring 6. At this time, the recording paper P is set by a lock mechanism (not shown). The flapper 5 is locked and maintained in this depressed position. In this state, when the paper feed cassette 4 is mounted at a predetermined position of the paper feed unit 3 of the image forming apparatus A along the white arrow a direction, a lock release mechanism (not shown) provided in the image forming apparatus A is installed. The lock is released by the action, and the upper layer side of the accumulated recording paper P is pressed against the separation paper feed roller 7 from below, and the drive shaft 7a of the separation paper feed roller 7 is driven by a drive system (non- Connected). When the separation paper feeding roller 7 is operated in this mounted state, the stacked recording paper P is fed one by one from the top layer paper in the white arrow b direction (paper feed direction) perpendicular to the white arrow a direction.・ It is sent.

  The end guide member 8 is installed at the bottom of the main body case 4a at the base side rear side (counter feed direction b) of the flapper 5 so that the front and rear positions can be adjusted via the guide rail 4c formed along the feed direction b. Then, the rear end of the recording paper P stored and stored is regulated (rear end alignment). Specifically, the end guide disclosed in Patent Document 1 is preferably employed, but is not limited thereto. The width guide members 9 and 10 for regulating the paper width installed on both sides of the flapper 5 are guide rails formed in the direction perpendicular to the paper feeding direction b at the bottom of the main body case 4a by the operation of the position adjusting unit 10a. The recording paper P placed and deposited on the flapper 5 is regulated from both sides in the width direction (width alignment). In the case of one side alignment, the width guide member 9 is fixed.

  As shown in FIGS. 4 and 5, the width guide member 10 includes a slide substrate 10b that reciprocally slides on the bottom surface of the main body case 4a in the width direction of the flapper 5 (direction perpendicular to the paper feeding direction b), and the slide substrate 10b. The regulation board 10c is erected on one side of the board 10b along the paper feeding direction b, and the elastic member 11 is attached to the inner side surface (recording paper side face) of the regulation board 10c. The inner side surface (same as above) of the regulation substrate 10c is an inclined surface, and the plate thickness is set to be small from the lower part to the upper part. An elastic member 11 is attached to the inclined inner surface of the regulation substrate 10c. The elastic member 11 includes a sponge body 11a attached to the inner side surface of the regulation substrate 10c and a resin film 11b attached integrally to the recording paper side surface of the sponge body 11a. The sponge body 11a is made of a sponge rubber blended with urethane foam, natural rubber or the like, and has a uniform thickness. When the recording paper is not deposited or when there is little remaining recording paper and the flapper 5 is moved upward, The recording paper side surface forms an inclined surface substantially parallel to the inner side surface of the regulating substrate 10c (see the two-dot chain line in FIG. 4 and FIG. 5). The resin film 11b is made of Teflon (registered trademark) having a uniform thickness (0.2 to 1 mm) and excellent in low friction, non-adhesiveness, and wear resistance, and the width edge of the deposited recording paper P. It is stuck on the vertical surface of the sponge body 11a so as to contact the part.

  The elastic member 11 configured as described above shows an example in which the setting of the magnitude of the elastic force in the vertical direction is made based on the difference in the shape of the elastic member. In the elastic member 11, the sponge body 11a has a uniform thickness from the lower part to the upper part, the recording paper surface side is inclined, and the distance from the width guide member 9 facing the lower part is set to be gradually reduced. When a large number of recording papers P are placed and deposited on the flapper 5 and the flapper 5 is pushed down, the sponge body 11a is strongly compressed by the width end portion of the recording paper P as shown in FIG. Then, the width of the recording paper P is regulated. At this time, since the lower part of the sponge body 11a is more strongly compressed, the elastic force (elastic reaction force) of the elastic member 11 acting in the width direction of the recording paper P gradually becomes weaker from the lower part to the upper part. FIG. 4 shows a state in which the recording paper P is placed and accumulated in a full state, the width guide member 10 is operated to the recording paper P side, and the resin film 11b is brought into contact with the width end portion of the recording paper P. . In this state, since the lower part of the elastic member 11 having a large elastic force acts on the lower layer part of the recording paper P against the stiffness of the added weight, the width is precisely regulated. The strength of the stiffness added by the accumulated weight gradually decreases toward the upper layer portion, but the elastic force of the elastic member 11 in contact with the width end portion of the recording paper P gradually decreases. It is made accurately. In particular, since the elastic force is the weakest at the uppermost layer, the recording paper P does not bend in the width direction, and the recording paper is inclined in the feeding / feeding and subsequent transport processes by the separation paper feeding roller 7. Thus, the image recording / discharge in the recording unit 2 can be performed smoothly.

  FIG. 5 shows a state where the accumulated recording paper P is reduced by feeding, and the flapper 5 is moved up by the action of the compression coil spring 6 and several recording papers P remain on the flapper 5. ing. In the upward movement process, the width end portion of the accumulated recording paper P slides on the resin film 11b and moves upward. However, the sliding contact is made smooth by the smoothness and low friction of the resin film 11b. In the state shown in FIG. 5, the stiffness of the recording paper P on the flapper 5 is based only on the stiffness of the recording paper P itself because almost no accumulated weight of the recording paper is added. Therefore, if a stronger elastic force than the width direction acts in such a state, the width direction will bend, but the upper part of the elastic member 11 is reduced by the degree of compression of the sponge body 11a as described above. Since the elastic force is set to be weak, the recording paper P is smoothly fed out and conveyed without such bending.

FIG. 6 shows a reference example of an example in which the magnitude of the elastic force in the vertical direction of the elastic member is set based on the difference in the shape of the elastic member. That is, the width guide member 10A of this reference example includes a slide board 10Ab similar to the above, a flat regulation board 10Ac erected on one side along the sheet feeding direction b of the slide board 10Ab, and the regulation board. It is composed of two elastic members 11A and 11A attached to the inner side surface (recording paper side surface) of 10Ac. The two elastic members 11A and 11A are spaced along the paper feeding direction b. Each elastic member 11A includes a sponge body 11Aa having a uniform thickness attached to the inner surface of the regulation substrate 10c, and the sponge body 11Aa. The same resin film 11Ab as described above, which is integrally attached to the recording paper side surface. The sponge body 11Aa is made of urethane foam or the like as described above, is formed in a trapezoidal shape, and is adhered to the inner side surface of the regulation substrate 10c so that the short side portion of the two parallel sides is located at the upper part. As described above, the sponge body 11Aa is formed in a trapezoidal shape, and the short side portion thereof is attached to the inner side surface of the regulation substrate 10c so as to be located at the upper portion, whereby the width direction of the recording paper P as the elastic member 11A. The elastic force acting on is set so as to gradually weaken from the lower part to the upper part. As a result, the same width regulating function as described above is achieved.

FIG. 7 shows an example in which the magnitude of the elastic force in the vertical direction of the elastic member is set based on the difference in the material of the elastic member. That is, the width guide member 10B of this reference example includes a slide board 10Bb similar to the above, a flat regulation board 10Bc erected on one side of the slide board 10Bb along the paper feeding direction b, and the regulation board. And an elastic member 11B attached to the inner side surface (recording paper side surface) of 10Bc. The elastic member 11B is attached to the inner surface of the regulation substrate 10Bc and has a uniform thickness and is prepared so that the expansion ratio changes in the surface area direction, and is attached to the recording paper side surface of the sponge member 11Ba. The resin film 11Bb is the same as the above. The sponge body 11Ba is made of urethane foam or the like as described above, and is set so that the expansion ratio gradually increases from the lower part to the upper part while being adhered to the inner surface of the regulation substrate 10Bc. The elastic force acting in the width direction of the recording paper P gradually decreases from the lower part to the upper part. Therefore, the same width regulating function as described above is achieved.

FIG. 8 shows another reference example in which the magnitude of the elastic force in the vertical direction of the elastic member is set based on the difference in the material of the elastic member. That is, the width guide member 10C of this reference example includes a slide board 10Cb similar to the above, a flat regulation board 10Cc erected on one side of the slide board 10Cb along the paper feeding direction b, and the regulation board. The elastic member 11C is attached to the inner side surface (side surface of the recording paper) of 10Cc. The elastic member 11C is a sponge body 11Ca having a uniform thickness attached to the inner side surface of the regulation substrate 10Cc and a height dimension smaller than that described above, and the same as described above, which is integrally attached to the recording paper side surface of the sponge body 11Ca. It consists of resin film 11Cb. The sponge body 11Ca is made of urethane foam or the like, and the resin film 11Cb has a height dimension larger than that of the sponge body 11Ca and is attached to the inner side surface of the regulation substrate 10c from the upper end of the sponge body 11Ca. The upper end portion of the resin film 11Cb projected upward is provided with a bent piece portion 11Cba that is bent outward (on the side opposite to the recording paper P). Therefore, the lower part of the elastic member 11C has an elastic force in which the elasticity of the sponge body 11Ca and the stiffness of the resin film 11Cb are combined, and only the stiffness of the resin film 11Cb is expressed as an elastic force at the upper part. In addition, since the bending reaction force of the resin film 11Cb based on the characteristics of the bonded integrated structure of the resin film 11Cb and the sponge body 11Ca is gradually reduced upward, the recording paper P as the elastic member 11C is reduced. The elastic force acting in the width direction gradually decreases from the lower part to the upper part. When the recording paper is placed and mounted due to the presence of the bent piece portion 11Cba, the bent piece portion 11Cba serves as a guide and promotes the bending of the resin film 11Cb to the outside. The bending reaction force to the outside of the resin film 11Cb is effective in expressing the change in the elastic force in the vertical direction of the elastic member 11C. Therefore, the same width regulating function as described above is achieved.

  Note that the method of setting the magnitude of the elastic force in the vertical direction of the elastic member is not limited to the above embodiment, and other methods can be employed. In addition, the paper feed cassette 4 of the embodiment can be inserted into and removed from the image forming apparatus A by the front loading method, but may be inserted and removed from the side of the image forming apparatus A.

1 is a schematic perspective view of an image forming apparatus using a paper feed cassette of the present invention. It is a schematic perspective view which shows one Embodiment of the paper feed cassette. It is a top view of the paper feed cassette. FIG. 4 is an enlarged sectional view taken along line XX in FIG. 3. FIG. 5 is a view similar to FIG. 4 showing a state in which the amount of recording paper deposited in the paper feed cassette of the embodiment is reduced. It is a schematic perspective view which shows the reference example of the example from which the magnitude of the elastic force of an up-down direction of an elastic member is set based on the difference in the shape of an elastic member. It is the same figure as FIG. 4 which shows the example which sets the magnitude of the elastic force of the up-down direction of an elastic member based on the difference in the material of an elastic member as a reference example . FIG. 5 is a view similar to FIG. 4 showing another reference example in which the magnitude of the elastic force in the vertical direction of the elastic member is set based on the difference in the material of the elastic member.

Explanation of symbols

4 Paper cassette 4a Body case 5 Flapper (paper push-up plate)
6 Compression coil spring (biasing means)
10, 10A, 10B, 10C Width guide member 11, 11A, 11B, 11C Elastic member A Image forming apparatus P Recording paper (paper)

Claims (2)

A main body case for accumulating and storing a large number of sheets, a paper push-up plate pivotally supported in the main body case so as to swing up and down, an urging means for urging the paper push-up board upward, and a paper push-up board A paper feed cassette provided with a width guide member for restricting paper width installed on a side part,
The width guide member includes a regulation substrate, and the recording paper side surface of the regulation substrate is an inclined surface, and an elastic member having a uniform thickness is attached to the inclined surface, and the upper portion of the elastic member has a small degree of compression. The paper feed cassette is characterized in that the elastic force is set so as to be weakened. In the paper feed cassette according to claim 1,
The sheet feeding cassette according to claim 1, wherein the elastic member includes a sponge body attached to a recording paper side surface of the regulation board and a resin film attached to the recording paper side surface of the sponge body .

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