JP2014234281A - Paper feed cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feed cassette capable of facilitating design.SOLUTION: A paper feed cassette 15 includes: a form tray 16; a push-up plate 42 which is disposed on a bottom surface of the form tray 16 and loads a plurality of forms thereon; a coil spring 43 which exerts an elastic force to the push-up plate 42 such that the push-up plate 42 pushes up an edge part of the downstream side in the transportation direction of the plurality of forms; an auxiliary push-up plate 46; a coil spring which exerts an elastic force to the auxiliary push-up plate 46 such that the auxiliary push-up plate 46 pushes up the push-up plate 42; and a regulation member 44b which is configured movably in the width direction of the plurality of forms and regulates the movement in the width direction of the plurality of forms. Therein, the force with which the push-up plate 42 is pushed up by the auxiliary push-up plate 46 is changed in accordance with a position of the regulation member 44b.

Description

  The present invention relates to a paper feed cassette, and more particularly to a paper feed cassette used in an image forming apparatus.

  As an invention relating to a conventional paper feed cassette having a paper feed mechanism capable of varying the paper feed pressure in accordance with the state of the paper, for example, a paper feed cassette described in Patent Document 1 is known. The paper feed cassette includes a bottom plate, a first elastic member, a second elastic member, and a position regulating member. The bottom plate is accommodated inside the paper feed cassette housing, on which paper is placed. The first elastic member is a coil spring that pushes up the bottom plate. The second elastic member is a leaf spring that pushes up the bottom plate. The paper pushed up to the bottom plate is pushed against the paper feed roller. The position restricting member restricts the side surface and the rear end of the sheet.

  In the paper feed cassette as described above, the position in the width direction of the position regulating member is changed according to the width of the paper. And the magnitude | size of the urging | biasing force of a 2nd elastic member is switched according to the position of the width direction of a position control member. As a result, the paper is pushed up with a force suitable for the paper size.

  However, the paper feed cassette described in Patent Document 1 has a problem that the design of the second elastic member is complicated. More specifically, the second elastic member functions as a push-up member that pushes up the bottom plate and also functions as a leaf spring. Therefore, it has been necessary to design the second elastic member so as to generate an appropriate urging force while designing the second elastic member in an appropriate shape as the push-up member.

JP 2003-95449 A

  Therefore, an object of the present invention is to provide a paper feed cassette that can be easily designed.

  A sheet feeding cassette according to an aspect of the present invention includes a main body, a first push-up member provided on a bottom surface of the main body, on which a plurality of print media are stacked, and a conveyance direction of the plurality of print media. A first elastic body that exerts an elastic force on the first push-up member, a second push-up member, the first push-up member, or the first push-up member so that the first push-up member pushes up the downstream end. A second elastic body that exerts an elastic force on the second push-up member and a width direction perpendicular to the transport direction of the plurality of print media so that the second push-up member pushes up the plurality of print media And a restricting member that restricts movement in the width direction of the plurality of print media, and the second push-up member pushes up the first push-up member or the plurality of print media. At the position of the regulating member Can vary Flip, it characterized.

  According to the present invention, the design can be easily performed.

1 is a diagram illustrating an overall configuration of an image forming apparatus. It is the external appearance perspective view and partial enlarged view of a paper feed cassette. FIG. 6 is a plan view of the paper feed cassette from above. FIG. 4 is a cross-sectional structural view taken along the line AA of the paper feed cassette of FIGS. 2 and 3. FIG. 4 is a cross-sectional structural view taken along the line BB of the paper feeding cassette of FIGS. 2 and 3. It is an external appearance perspective view of an auxiliary push-up plate, a shaft, a lever, a coil spring, and a pedestal. It is the external appearance perspective view and partial enlarged view of a paper feed cassette. FIG. 8 is a cross-sectional structural view taken along the line AA of the paper feed cassette in FIG. 7. FIG. 8 is a cross-sectional structural view taken along the line BB of the paper feed cassette of FIG. 7. 6 is a graph showing the relationship between the paper size and the paper feed pressure in the first comparative example. 6 is a graph showing a relationship between a sheet size and a sheet feeding pressure in an example. FIG. 10 is a plan view of a comparative example in which sheets having a relatively long length in the transport direction are stacked. FIG. 10 is a plan view of a comparative example in which sheets having a relatively short length in the transport direction are stacked. 6 is a graph showing the relationship between the paper length or paper width and the paper feed pressure.

  Hereinafter, an image forming apparatus including a paper feed cassette according to an embodiment of the present invention will be described with reference to the drawings.

(Configuration of image forming apparatus)
Hereinafter, an image forming apparatus including a paper feed cassette according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating an overall configuration of the image forming apparatus 1. In FIG. 1, the left-right direction of the paper surface is simply referred to as the left-right direction, the front-rear direction of the paper surface is simply referred to as the front-rear direction, and the up-down direction of the paper surface is simply referred to as the up-down direction.

  The image forming apparatus 1 is an electrophotographic color printer and is configured to synthesize images of four colors (Y: yellow, M: magenta, C: cyan, K: black) in a so-called tandem system. is there. The image forming apparatus 1 may be a monochrome image forming apparatus or an inkjet image forming apparatus. The image forming apparatus 1 has a function of forming an image on a sheet (printing medium) based on image data read by a scanner. As shown in FIG. 1, the printing unit 2, the main body 3, and a paper feeding cassette 15 are provided. , A timing roller pair 19, a fixing unit 20, a paper discharge roller pair 21, and a paper discharge tray 23.

  The main body 3 is a housing of the image forming apparatus 1 and houses the printing unit 2, the paper feed cassette 15, the timing roller pair 19, the fixing unit 20, and the paper discharge roller pair 21.

  The paper feed cassette 15 serves to supply paper one by one, and generally includes a paper tray 16 and a paper feed roller 17. A plurality of sheets in a state before printing are stacked on the sheet tray 16. The paper feed roller 17 takes out the paper placed on the paper tray 16 one by one. The timing roller pair 19 conveys the paper while adjusting the timing so that the toner image is secondarily transferred to the paper in the printing unit 2. Details of the paper feed cassette 15 will be described later.

  The printing unit 2 forms a toner image on the paper supplied from the paper feed cassette 15, and forms image forming units 22Y, 22M, 22C, and 22K, optical scanning devices 6Y, 6M, 6C, and 6K, and transfer units 8Y, 8M, and so on. 8C and 8K, an intermediate transfer belt 11, a driving roller 12, a driven roller 13, a secondary transfer roller 14, and a cleaning device 18. The image forming units 22Y, 22M, 22C and 22K include photosensitive drums 4Y, 4M, 4C and 4K, chargers 5Y, 5M, 5C and 5K, developing devices 7Y, 7M, 7C and 7K, and cleaners 9Y, 9M and 9C, 9K are included.

  The photosensitive drums 4Y, 4M, 4C, and 4K are provided in the main body 3 and have a cylindrical shape. The photosensitive drums 4Y, 4M, 4C, and 4K are rotated clockwise in FIG. The chargers 5Y, 5M, 5C, and 5K charge the peripheral surfaces of the photosensitive drums 4Y, 4M, 4C, and 4K. The optical scanning devices 6Y, 6M, 6C, and 6K scan the beams BY, BM, BC, and BK on the peripheral surfaces of the photosensitive drums 4Y, 4M, 4C, and 4K under the control of a CPU (not shown). As a result, electrostatic latent images are formed on the peripheral surfaces of the photosensitive drums 4Y, 4M, 4C, and 4K.

  The developing devices 7Y, 7M, 7C, and 7K are provided in the main body 3, and apply toner to the photosensitive drums 4Y, 4M, 4C, and 4K to develop a toner image based on the electrostatic latent image.

  The intermediate transfer belt 11 is stretched between the driving roller 12 and the driven roller 13. To the intermediate transfer belt 11, the toner images developed on the photosensitive drums 4Y, 4M, 4C, and 4K are primarily transferred. The transfer portions 8Y, 8M, 8C, and 8K are disposed so as to face the inner peripheral surface of the intermediate transfer belt 11, and the toner images formed on the photosensitive drums 4Y, 4M, 4C, and 4K are transferred to the intermediate transfer belt 11. It plays the role of primary transfer. The cleaners 9Y, 9M, 9C, and 9K collect toner remaining on the peripheral surfaces of the photosensitive drums 4Y, 4M, 4C, and 4K after the primary transfer. The driving roller 12 is rotated by an intermediate transfer belt driving unit (not shown in FIG. 1) to drive the intermediate transfer belt 11 counterclockwise. As a result, the intermediate transfer belt 11 conveys the toner image to the secondary transfer roller 14.

  The secondary transfer roller 14 faces the intermediate transfer belt 11 and has a drum shape. The secondary transfer roller 14 secondarily transfers the toner image carried by the intermediate transfer belt 11 to a sheet passing between the secondary transfer roller 14 and the intermediate transfer belt 11 by applying a transfer voltage. The cleaning device 18 removes the toner remaining on the intermediate transfer belt 11 after the secondary transfer of the toner image onto the paper.

  The sheet on which the toner image is secondarily transferred is conveyed to the fixing unit 20. The fixing unit 20 fixes the toner image on the paper by performing heat treatment and pressure treatment on the paper.

  The paper discharge roller pair 21 discharges the paper P that has passed through the fixing unit 20 onto the paper discharge tray 23. Printed paper P is stacked on the paper discharge tray 23.

(Structure of paper cassette)
Hereinafter, the configuration of the paper feed cassette 15 will be described with reference to the drawings. FIG. 2 is an external perspective view and a partially enlarged view of the paper feed cassette 15. FIG. 2 shows the paper feed cassette 15 when a paper having a relatively large width (for example, A3 size) is set. In FIG. 2, the push-up plate 42 is omitted. FIG. 3 is a plan view of the paper feed cassette 15 from above. FIG. 4 is a cross-sectional structural view taken along line AA of the paper feed cassette 15 of FIGS. 2 and 3. FIG. 5 is a cross-sectional structural view taken along the line BB of the paper feed cassette 15 of FIGS. 2 and 3. FIG. 6 is an external perspective view of the auxiliary push-up plate 46, the shaft 48, the lever 50, the coil spring 52, and the pedestal 54. Note that the paper P is conveyed in the right direction. Therefore, in the following, the left-right direction is referred to as the transport direction, and the front-rear direction is referred to as the paper width direction.

  The paper feed cassette 15 is inserted into the bottom of the main body 3 of the image forming apparatus 1 from the front side, and is configured to be detachable from the main body 3. 2 to 6, the paper feed cassette 15 includes a paper tray 16, a paper feed roller 17, a push-up plate 42, a coil spring 43, regulating members 44a and 44b, pins 45a and 45b, and an auxiliary push-up plate 46. , A shaft 48, a lever 50, a coil spring 52 and a pedestal 54.

  As shown in FIG. 3, the paper tray 16 constitutes a main body of the paper feed cassette 15 and is a rectangular parallelepiped box having an upper surface opened. The paper tray 16 includes a bottom surface 16a, a right surface 16b, a left surface 16c, a back surface 16d, a front surface 16e, and a panel 16f. The panel 16f is disposed with a gap in front of the front surface 16e. The panel 16f is provided with a handle for the user to pull out the paper feed cassette 15.

  The paper feed roller 17 is a cylindrical roller provided on the upper side of the right surface 16b at the center in the front-rear direction of the right surface 16b. The paper feed roller 17 is rotatably supported by a shaft and is rotated by a motor (not shown).

  As shown in FIGS. 3 and 5, the push-up plate 42 is provided on the bottom surface 16 a of the paper tray 16 and is configured by bending a metal plate or the like. The push-up plate 42 includes a main body 42a and bent portions 42b and 42c. The main body 42a is provided on the bottom surface 16a and has a rectangular shape. However, the main body 42a is provided with openings for attaching regulating members 44a and 44b described later. The bent portion 42b is formed by being bent upward from the rear side of the main body 42a. Thereby, the bending part 42b has opposed the back surface 16d. The bent portion 42c is formed by being bent upward from the front side of the main body 42a. Thereby, the bending part 42c has opposed the front surface 16e.

  As shown in FIG. 3, the pin 45a is a shaft that protrudes rearward from the front surface 16e, and penetrates the vicinity of the left end of the bent portion 42c. The pin 45b is a shaft that protrudes from the back surface 16d toward the front side, and penetrates the vicinity of the left end of the bent portion 42a. As a result, the push-up plate 42 is rotatably attached to the paper tray 16 with the pins 45a and 45b positioned near the left end of the push-up plate 42 as the central axis.

  As shown in FIG. 5, the coil spring 43 is an elastic body that exerts an elastic force on the push-up plate 42 so that the push-up plate 42 pushes up the right end of the paper P (that is, the end on the downstream side in the transport direction). The coil spring 43 is provided between the bottom surface 16 a and the main body 42 a and is located immediately below the paper feed roller 17.

  The restricting members 44a and 44b are configured to be movable in the width direction (that is, the front-rear direction) and restrict the movement of the paper in the width direction. As shown in FIG. 2, the restricting members 44a and 44b are plate-like members having surfaces that face each other and are perpendicular to the front-rear direction. The restricting members 44a and 44b are attached to the bottom surface 16a through openings provided in the main body 42a. The restricting members 44a and 44b can be slid in opposite directions in conjunction with each other by a rack and pinion mechanism (not shown). An opening (concave portion) Op is provided near the lower end of the regulating member 44b.

  As shown in FIGS. 3 and 6, the auxiliary push-up plate 46 is provided between the bottom surface 16a of the paper tray 16 and the main body 42a of the push-up plate 42, and is configured by bending a metal plate or the like. . The auxiliary push-up plate 46 includes a main body 46a and a convex portion 46b. The main body 46a has a rectangular shape. The protrusion 46b protrudes from the right rear corner of the main body 46a toward the rear side.

  As shown in FIGS. 2 and 6, the shaft 48 is an axis that extends in the width direction and penetrates the back surface 16d and the front surface 16e. The left end of the main body 46 a of the auxiliary push-up plate 46 is attached to the center of the shaft 48 in the front-rear direction. Thus, the shaft 48 supports the auxiliary push-up plate 46 so as to be rotatable with respect to the paper tray 16.

  As shown in FIGS. 4 and 6, the lever 50 is a triangular plate-like member, and is provided in a gap between the front surface 16e and the panel 16f. The lower end of the lever 50 is connected to the front end of the shaft 48. As a result, the auxiliary push-up plate 46 and the lever 50 can rotate about the shaft 48 as a central axis.

  As shown in FIGS. 4 and 6, the pedestal 54 is fixed on the bottom surface 16a in a gap between the front surface 16e and the panel 16f. The coil spring 52 is connected between the upper end of the lever 50 and the pedestal 54. The coil spring 52 pulls the lever 50 so that the lever 50 falls to the left side. As a result, a force is exerted on the auxiliary push-up plate 46 to rotate counterclockwise about the shaft 48. The right end of the main body 46 a of the auxiliary push-up plate 46 pushes up the push-up plate 42. In this manner, the coil spring 52 exerts an elastic force on the auxiliary push-up plate 46 so that the push-up plate 42 is pushed up by the auxiliary push-up plate 46.

  Incidentally, the paper feed cassette 15 can change the magnitude of the force by which the push-up plate 42 pushes up the paper P in accordance with the width of the paper P. More specifically, in the paper feed cassette 15, the force by which the auxiliary push-up plate 46 pushes up the push-up plate 42 changes according to the positions of the regulating members 44a and 44b. When the width of the paper P is relatively small, the force by which the auxiliary push-up plate 46 pushes up the paper P becomes relatively small, and the force by which the push-up plate 42 pushes up the paper P becomes relatively small. On the other hand, when the width of the paper P is relatively large, the force by which the auxiliary push-up plate 46 pushes up the paper P becomes relatively large, and the force by which the push-up plate 42 pushes up the paper P becomes relatively large. This will be described below with reference to the drawings.

  FIG. 7 is an external perspective view and a partially enlarged view of the paper feed cassette 15. FIG. 7 shows the paper feed cassette 15 when paper having a relatively small width (for example, postcard size) is set. In FIG. 7, the push-up plate 42 is omitted. FIG. 8 is a cross-sectional structural view taken along the line AA of the paper feed cassette 15 of FIG. FIG. 9 is a cross-sectional structure view taken along the line BB of the paper feed cassette 15 of FIG.

  When the width of the paper P is relatively small (that is, when the regulating members 44a and 44b regulate the paper P having a relatively small width), as shown in FIG. 46b is inserted. That is, the opening Op engages with the convex portion 46b. Therefore, as shown in FIGS. 7 to 9, the regulating member 44 b holds the auxiliary push-up plate 46 so that the auxiliary push-up plate 46 does not contact the push-up plate 42. Thereby, the paper P (not shown) stacked on the push-up plate 42 is pushed up by the force by which the push-up plate 42 is pushed up by the coil spring 43. That is, the paper P is pushed up with a relatively small force.

  When the width of the paper P is relatively large (that is, when the regulating members 44a and 44b regulate the paper P having a relatively large width), as shown in FIG. 46b is not inserted. That is, the opening Op and the convex portion 46b are not engaged. For this reason, the restricting member 44b releases the holding of the auxiliary push-up plate 46 so that the auxiliary push-up plate 46 contacts the push-up plate 42. Therefore, the auxiliary push-up plate 46 pushes up the push-up plate 42. Therefore, the paper P (not shown) loaded on the push-up plate 42 is pushed up by the force by which the push-up plate 42 is pushed up by the coil spring 43 and the force by which the auxiliary push-up plate 46 is pushed up by the coil spring 52. That is, the paper P is pushed up with a relatively large force.

(effect)
According to the paper feed cassette 15 configured as described above, the design can be easily performed. More specifically, in the paper feed cassette described in Patent Document 1, the second elastic member functions as a push-up member that pushes up the bottom plate and also functions as a leaf spring. Therefore, it has been necessary to design the second elastic member so as to generate an appropriate urging force while designing the second elastic member in an appropriate shape as the push-up member.

  On the other hand, in the paper feed cassette 15, the auxiliary push-up plate 46 that pushes up the push-up plate 42 and the coil spring 52 that exerts an elastic force on the auxiliary push-up plate 46 are configured by separate members. Therefore, when the auxiliary push-up plate 46 is designed, the auxiliary push-up plate 46 may be designed in an appropriate shape as a push-up member, and it is not necessary to design the auxiliary push-up plate 46 in an appropriate shape as an elastic body. Similarly, when designing the coil spring 52, the coil spring 52 may be designed in an appropriate shape as an elastic body, and it is not necessary to design the coil spring 52 in an appropriate shape as a push-up plate. Therefore, in the paper feed cassette 15, the auxiliary push-up plate 46 and the coil spring 52 can be easily designed.

  Further, in the paper feed cassette 15, the regulating members 44a and 44b can be easily slid. More specifically, in the paper feed cassette described in Patent Document 1, push-up ribs provided on side guides corresponding to the restricting members 44a and 44b are always in contact with the push-up member. For this reason, a frictional force is generated between the push-up rib and the push-up member, and smooth sliding of the side guide is hindered.

  On the other hand, in the paper feed cassette 15, when the width of the paper P is relatively small, as shown in FIG. 7, the convex portion 46b is inserted into the opening Op. That is, the opening Op engages with the convex portion 46b. On the other hand, when the width of the paper P is relatively large, as shown in FIG. 2, the opening Op and the convex portion 46b are not engaged. Thus, the regulating member 44b and the auxiliary push-up plate 46 are not always in contact. Therefore, in the paper feed cassette 15, the regulating members 44a and 44b can be easily slid.

  Further, in the paper feed cassette 15, the magnitude of the force with which the paper P contacts the paper feed roller 17 can be brought close to an appropriate value regardless of the width of the paper P, so that paper feed errors can be reduced. More specifically, when the width of the paper P changes, the weight of the paper P also changes. Therefore, the weight of the paper P stacked on the push-up plate also changes. Here, if the magnitude of the force by which the push-up plate pushes up the paper P is constant regardless of the width of the paper P, there is a possibility that a paper feed error such as a pick mistake or double feed may occur as described below. . When the width of the paper P is relatively small, the weight of the paper P stacked on the push-up plate is relatively small. Therefore, the paper P contacts the paper feed roller 17 with a relatively large force. In this case, there is a possibility that multiple feeding in which a plurality of sheets P are simultaneously conveyed by the sheet feeding roller 17 may occur. On the other hand, when the width of the paper P is relatively large, the weight of the paper P stacked on the push-up plate is relatively large. Therefore, the paper P contacts the paper feed roller 17 with a relatively small force. In this case, there is a possibility that a pick mistake that the paper P is not conveyed by the paper feed roller 17 may occur.

  Therefore, in the paper feed cassette 15, since the width of the paper P is relatively small, when the weight of the paper P is small, the paper P is pushed up by the force by which the push-up plate 42 is pushed up by the coil spring 43. That is, the paper P is pushed up with a relatively small force. On the other hand, when the weight of the paper P is large because the width of the paper P is relatively large, the paper P is pushed up by the coil spring 52 and the force by which the push-up plate 42 is pushed up by the coil spring 43 and the auxiliary push-up plate 46. It is pushed up by force. That is, the paper P is pushed up with a relatively large force. As a result, the magnitude of the force with which the paper P contacts the paper feed roller 17 can be brought close to an appropriate value regardless of the width of the paper P, and paper feed errors can be reduced.

  The inventor of the present application conducted the following experiment in order to clarify that the sheet feeding error can be reduced in the sheet feeding cassette 15. Specifically, when the sheet P of A6, B5, A4, and A3 is vertically conveyed in the sheet feeding cassette 15 (hereinafter, an example), the magnitude of the force with which the sheet P contacts the sheet feeding roller 17 (hereinafter, (Also called paper feed pressure). Further, the inventor of the present application produced a paper feed cassette (first comparative example) in which the auxiliary push-up plate 46 and the coil spring 52 were removed from the paper feed cassette 15. Then, in the first comparative example, when the A6, B5, A4, and A3 sheets P were vertically conveyed, the magnitude of the force with which the sheets P contact the sheet feeding roller (hereinafter also referred to as sheet feeding pressure) was examined. .

  FIG. 10 is a graph showing the relationship between the size of the paper P and the paper feed pressure in the first comparative example. FIG. 11 is a graph showing the relationship between the size of the paper P and the paper feed pressure in the example. In the first comparative example, as shown in FIG. 10, it can be seen that when the size of the paper P increases, the paper feed pressure is insufficient and a pick mistake occurs. In the first comparative example, if the spring constant of the coil spring 43 is increased, the size of the paper P is reduced instead of suppressing the occurrence of pick mistakes when the size of the paper P is increased. Sometimes double feed occurs. On the other hand, in the embodiment, as shown in FIG. 11, pick mistakes and double feeding do not occur regardless of the size of the paper P. Therefore, according to the paper feed cassette 15, it can be seen that paper feed errors can be reduced.

  Further, in the paper feed cassette 15, the magnitude of the force with which the paper P contacts the paper feed roller 17 (paper feed pressure) can be brought close to an appropriate value regardless of the width of the paper P for the following reasons. Therefore, paper feeding errors can be reduced. In the paper feed cassette 15 (example), the magnitude of the force for pushing up the paper is changed according to the width of the paper. On the other hand, as a second comparative example, the inventor of the present application manufactured a paper feed cassette that changes the magnitude of the force for pushing up the paper according to the length of the paper. FIG. 12 is a plan view of a comparative example in which sheets P having a relatively long length in the transport direction are stacked. FIG. 13 is a plan view of a comparative example in which sheets P having a relatively short length in the transport direction are stacked. FIG. 14 is a graph showing the relationship between the length of the paper P or the width of the paper P and the paper feed pressure. In FIG. 14, in the comparative example, the horizontal axis indicates the length of the paper P, and in the embodiment, the horizontal axis indicates the width of the paper P. In FIG. 14, the vertical axis indicates the paper feed pressure.

  In the comparative example, a push-up plate (corresponding to the push-up plate 42), an auxiliary push-up plate (corresponding to the auxiliary push-up plate 46), a regulating member 150, a first coil spring (corresponding to the coil spring 43), and a second coil spring (coil) Equivalent to the spring 52). Sheets P are stacked on the push-up plate. The push-up plate is pushed up by the first coil spring. The auxiliary push-up plate is pushed up by the second coil spring and pushes up the push-up plate. When the length in the paper transport direction is relatively long, the paper P is pushed up by the push-up plate, and the push-up plate is pushed up by the auxiliary push-up plate. On the other hand, when the length of the sheet in the conveyance direction is relatively short, the sheet is pushed up by the push-up plate. However, since the regulating member 150 regulates the movement of the auxiliary push-up plate, the push-up plate is not pushed up by the auxiliary push-up plate. Thereby, the magnitude of the force for pushing up the paper is changed according to the length of the paper in the conveyance direction.

  However, in the comparative example, it is difficult to push up the paper with an appropriate force. Hereinafter, A4 horizontal conveyance and A3 vertical conveyance will be described as examples. As shown in FIGS. 12 and 13, the paper width in A4 horizontal conveyance is the same as the paper width in A3 vertical conveyance. On the other hand, the length of the paper in A3 vertical conveyance is twice the length of the paper in A4 horizontal conveyance. In this case, the sheet is pushed up with a relatively small force in the A4 horizontal conveyance, and the sheet is pushed up with a relatively large force in the A3 vertical conveyance.

  However, in the A3 vertical conveyance, as shown in FIG. 12, the vicinity of the rear end in the paper conveyance direction is not stacked on the stacking plate and is not pushed up by the stacking plate. That is, as shown in FIGS. 12 and 13, the weight of the paper stacked on the stacking plate in A3 vertical transport is not significantly different from the weight of the paper stacked on the stacking plate in A4 horizontal transport. On the other hand, the magnitude of the force that pushes up the paper in A3 vertical conveyance is larger than the magnitude of the force that pushes up the paper in A4 horizontal conveyance. For this reason, in A3 vertical conveyance, the force with which the sheet is pushed up becomes too large, and the force with which the sheet comes into contact with the sheet feeding roller (sheet feeding pressure) may become too large. As a result, as shown in FIG. 14, there is a possibility that double feeding may occur in A3 vertical conveyance in which the length of the paper in the conveyance direction is relatively long.

  On the other hand, in the paper feed cassette 15, the magnitude of the force for pushing up the paper is not changed according to the length of the paper, but the magnitude of the force for pushing up the paper is changed according to the width of the paper. As a result, in the paper feed cassette 15, the paper P can be pushed up with a force having a magnitude corresponding to the weight of the paper P stacked on the push-up plate 42. As a result, in the paper feed cassette 15, the magnitude of the force with which the paper P contacts the paper feed roller 17 can be brought close to an appropriate value regardless of the width of the paper P. Therefore, as shown in FIG. Paper errors can be reduced.

  Further, in the paper feed cassette 15, the height of the paper feed cassette 15 can be reduced. More specifically, the lever 50 and the coil spring 52 are provided in the gap between the front surface 16e and the panel 16f, so that they are provided outside the area where the paper P is stacked when viewed from above. . That is, the lever 50 and the coil spring 52 are not provided below the auxiliary push-up plate 46. As a result, the auxiliary push-up plate 46 can be brought close to the bottom surface 16a. As a result, it is possible to reduce the height of the paper feed cassette 15.

(Other embodiments)
The paper feed cassette according to the present invention is not limited to the paper feed cassette 15 and can be changed within the scope of the gist thereof.

  Although the auxiliary push-up plate 46 pushes up the push-up plate 42, the paper P may be pushed up directly.

  The coil spring 52 may be provided between the auxiliary push-up plate 46 and the bottom surface 16a.

  Further, instead of the coil spring 52, an elastic body such as rubber may be used.

  As described above, the present invention is useful for a paper feed cassette, and is particularly excellent in that it can be easily designed.

DESCRIPTION OF SYMBOLS 15 Paper feed cassette 16 Paper tray 17 Paper feed roller 42 Push-up plate 43,52 Coil spring 44a, 44b Restriction member 45a, 45b Pin 46 Auxiliary push-up plate 48 Shaft 50 Lever 54 Base

Claims (7)

The body,
A first push-up member provided on the bottom surface of the main body and on which a plurality of print media are stacked;
A first elastic body that exerts an elastic force on the first push-up member so that the first push-up member pushes up the downstream end in the transport direction of the plurality of print media;
The second push-up member;
A second elastic body that exerts an elastic force on the second push-up member so that the second push-up member pushes up the first push-up member or the plurality of print media;
A restricting member configured to be movable in a width direction orthogonal to a conveying direction of the plurality of print media, and restricting movement in the width direction of the plurality of print media;
With
The force by which the second push-up member pushes up the first push-up member or the plurality of print media varies according to the position of the regulating member;
A paper cassette characterized by When the restriction member restricts the plurality of print media having a relatively small width, the force by which the second push-up member pushes up the first push-up member or the plurality of print media is relatively Small,
When the regulating member regulates the plurality of print media having a relatively large width, the force by which the second push-up member pushes up the first push-up member or the plurality of print media is relatively Big to the
The paper feed cassette according to claim 1. When the restriction member restricts the plurality of print media having a relatively small width, the second push-up member does not come into contact with the first push-up member or the plurality of print media. When the second push-up member is held and the plurality of print media having a relatively large width are regulated, the second push-up member is the first push-up member or the plurality of print media. Releasing the holding of the second push-up member so as to contact
The sheet feeding cassette according to claim 1, wherein the sheet feeding cassette is characterized by the following. The second push-up member is rotatably attached to the main body,
The restriction member is provided with a recess,
The second push-up member is provided with a convex portion,
When the regulating member regulates the plurality of print media having a relatively small width, the concave portion and the convex portion are engaged,
When the restricting member restricts the plurality of print media having a relatively large width, the concave portion and the convex portion are not engaged;
The paper feed cassette according to any one of claims 1 to 3, wherein A central axis extending in the width direction and rotatably supporting the second push-up member;
Outside the region where the plurality of print media are stacked, a lever connected to the central axis;
Is further provided,
The second elastic member is connected to the lever outside an area where the plurality of print media are stacked;
The paper feed cassette according to any one of claims 1 to 4, wherein The second push-up member pushes up the first push-up member;
The paper feed cassette according to any one of claims 1 to 5, wherein The second elastic member is a coil spring;
The paper feed cassette according to any one of claims 1 to 6, wherein:

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