JP2010030692A - Paper feeding cassette and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of impact sound to be generated when pulling out a cassette. <P>SOLUTION: This paper feeding cassette is provided with a case body part 301 provided to be inserted and pulled out in/of the image forming device, an elevating plate 304 provided in the case body part 301, being upward turned above the case body part 301 by external force while the case body part 301 is inserted into the image forming device, and being turned toward a bottom face part 301b of the case body part 301 due to its self-weight by releasing the external force while the case body part 301 is pulled out of the image forming device, a tray 302 tilting in accordance with the turn of the elevating plate 304 to load papers to be fed into the image forming device on its main surface, and a distal end part 10a of an earth spring 10 being always abutted on the elevating plate 304 in a scope of turn of the elevating plate 304 to reduce the force for turning the elevating plate 304 when releasing the external force. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a paper feed cassette used in an image forming apparatus such as a copying machine or a printer, and an image forming apparatus using the same.

  2. Description of the Related Art Conventionally, image forming apparatuses such as copiers and printers have a built-in paper feeding device that supplies paper to be subjected to image formation. FIG. 10 is a schematic configuration diagram of such an image forming apparatus.

  As illustrated in FIG. 10, the image forming apparatus 100 generates an image as a toner image and forms an image forming unit 130 on a sheet supplied from the manual feed tray 110 or the sheet feeding device 120, and the toner image on the sheet. An image fixing unit 140 that fixes the printed matter is provided.

  A plurality of sheet feeding devices 120 are stacked below the image forming unit 130 and the like.

  Each paper feeding device 120 includes a paper feeding cassette that stores paper and a paper feeding mechanism that guides the paper from the paper feeding cassette to the image forming unit 130. It is carried into the image forming unit 130 through a common conveyance path.

  FIG. 11 is a schematic side view illustrating the configuration of the paper feeding device 120. As shown in FIG. 11, in the paper feeding device 120, the paper feeding mechanism 200 includes a pick roller 201, a feed roller 202, a retard roller 203, and the like provided on the main body side of the image forming apparatus 100. Has a structure separable from the main body side of the image forming apparatus 100.

  In the paper feed mechanism 200, the pick roller 201 contacts the surface of the paper placed on the tray 302 in the paper feed cassette 300 and feeds it to the feed roller 202 side. Further, the feed roller 202 and the retard roller 203 are disposed to face each other, rotate so as to sandwich the sheet in the nip, and guide the conveyance path to the image forming apparatus 100 indicated by an arrow in the drawing.

  In addition, the paper feed cassette 300 includes a tray 302 disposed in the housing unit 301. One end portion of the tray 302 is fixed to the wall surface portion 301 a of the housing portion 301 by a rotation end 303 so as to be rotatable.

  A rising plate 304 is provided in a direction facing the other end of the tray 302. The ascending plate 304 is fixed to a rotating shaft 305 provided in the vicinity of the retard roller 203, and changes the inclination angle according to the rotation of the rotating shaft 305. The rotation shaft 305 extends to the main body side of the image forming apparatus 100, and a rotational force is transmitted by a power source such as an actuator provided in the image forming apparatus 100. The end 304a of the rising plate 304 is in contact with the back surface of the tray 302 to lift the tray 302. When the rising plate 304 is rotated, the contact position between the end 304a and the back surface of the tray 302 is changed. Change the tilt angle. This creates a state in which the paper placed on the main surface of the tray 302 can be supplied to the paper feed mechanism 200.

  In the image forming apparatus 100 as described above, the following problems have been known for the paper feed cassette 300.

  As shown in FIG. 12, the paper feed cassette 300 is pulled out from the image forming apparatus 100 in the direction of the arrow B in the figure when paper is replenished. At this time, the tray 302, the pick roller 201 in the image forming apparatus 100, etc. In order to prevent interference with the tray 302, the inclined state of the tray 302 is forcibly released, and the tray 302 is rotated and dropped by its own weight toward the bottom surface portion 301b of the housing portion 301.

  This is due to the following mechanism. As shown in FIG. 13, the rising plate 304 is fixed to the rotation shaft 305, and the sector gear 306 provided at the end of the rotation shaft 305 receives the rotational force from the input gear 307, whereby the tray 302. Rotate to lift up.

  On the other hand, the end 309 of the rotation shaft 308 provided with the input gear 307 and the end 311 of the rotation shaft 310 of the actuator of the image forming apparatus 100 are connected by an uneven joint structure. When the paper feed cassette 300 is pulled out in the direction B, the end 309 and the end 311 are separated.

  As a result, the rotation shaft 308 loses support, and the rising plate 304 falls in the direction of arrow C in the figure. As the rising plate 304 is dropped, the tray 302 is released from contact with the end 304a of the rising plate 304 and falls in the direction of arrow D in the figure. As a result, both the ascending plate 304 and the tray 302 collide with the bottom surface portion 301b of the housing portion 301 to generate an impact sound.

As a technique for reducing such an impact sound, as shown in FIG. 14, a technique is known in which a spring 400 for absorbing an impact is provided on a bottom surface portion 301b of a housing 301 (see Patent Document 1). ). The spring 400 is located immediately below the tray 302. When the paper feeding cassette 300 is pulled out, the dropped tray 302 collides with the spring 400 first, and the momentum of the drop is reduced, so that the impact with the bottom surface portion 301b is reduced. Sound is reduced.
Japanese Patent Laid-Open No. 10-329958

  However, the paper feed cassette as shown in Patent Document 1 has the following problems. That is, the spring 400 directly receives the impact of the tray 302, but the tray 302 changes in weight from the state where the maximum number of sheets are loaded to the state where it is emptied when the image forming apparatus 100 is used. Variations in impact mitigation performance occur with changes in weight. Further, as shown in FIG. 13, the rising plate 304 is actually already provided at the position where the spring 400 is provided, and it is considered that a design difficulty arises in the installation of the spring 400 which is a new member.

  The present invention has been made in view of such problems, and an object thereof is to provide a paper feed cassette capable of reliably reducing the impact sound generated when the cassette is pulled out, and an image forming apparatus using the same. .

In order to achieve the above object, a first aspect of the present invention is a paper feed cassette for feeding paper to an image forming apparatus,
A casing provided so as to be freely inserted and removed from the image forming apparatus;
Provided in the casing, and when the casing is inserted into the image forming apparatus, the casing is rotated upward by the external force, and the casing is extracted from the image forming apparatus. In a state where the external force is released, a rising plate that rotates by its own weight toward the bottom surface of the housing part,
A mounting plate that mounts a sheet fed to the image forming apparatus on its main surface, which is inclined according to the rotation of the rising plate;
A sheet feeding cassette provided with a buffer member that is in constant contact with the rising plate in the rotation range of the rising plate and softens the rotational force of the rising plate when the external force is released.

The second aspect of the present invention includes an earth spring disposed on the bottom surface of the casing portion,
The shock-absorbing member is the paper feed cassette according to the first aspect of the present invention, wherein the tip of the earth spring protrudes from the bottom surface and comes into contact with the rising plate.

  A third aspect of the present invention is the paper feed cassette according to the second aspect of the present invention, wherein a tip of the earth spring is in contact with the rising plate on a side adjacent to the rotating shaft of the rising plate.

Moreover, 4th this invention is arrange | positioned in the direction orthogonal to the rotating shaft of the said rising plate, and the said earth spring containing the said buffer member,
The tip of the earth spring is the paper feed cassette according to the second aspect of the present invention, which is inclined in the same direction as the mounting plate and is in contact with the rising plate.

Further, in the fifth aspect of the present invention, the tip of the earth spring is curved in an annular shape toward the bottom surface of the housing part,
The paper feeding cassette according to the second aspect of the present invention, wherein a concave portion for accommodating the tip of the earth spring is formed on the bottom surface of the casing.

According to a sixth aspect of the present invention, there is provided an image forming unit that forms an image on a sheet;
A paper feeding unit that feeds the paper to the image forming unit,
The sheet feeding unit is an image forming apparatus having any one of the first to fifth sheet feeding cassettes of the present invention.

  According to the present invention as described above, it is possible to provide a paper feed cassette capable of reliably reducing the impact sound generated when the cassette is pulled out, and an image forming apparatus using the paper feed cassette.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing a configuration in the vicinity of a paper feeding device including a paper feeding cassette 1 according to an embodiment of the present invention. However, the same parts as those in the conventional example shown in FIG. In FIG. 1, the ground spring 10 is provided on the bottom surface portion 301 b of the housing portion 301 and is a means for grounding by being connected to an electric system such as the paper feed mechanism 200. Further, the tip portion 10a of the ground spring 10 is curved so as to protrude from the bottom surface portion 301b as shown in the figure, and is in contact with the rising plate 304. In addition, an opening 20 is provided at a portion corresponding to a position directly below the tip portion 10a of the ground spring 10 on the bottom surface portion 301b.

  FIG. 2 is a perspective view of an essential part of the configuration shown in FIG. However, portions such as the paper feed mechanism 200 included on the image forming apparatus 100 side are omitted. As shown in FIG. 2, the bottom surface portion 301b is provided with a groove 301c for arranging the earth spring 10. Further, the tray 302 is fixed in an inclined state by being supported by the rising plate 304. The input gear 307 fixes the rotating shaft 305 to which the rising plate 304 is connected by fixing the sector gear 306 at a predetermined angle.

  Next, FIG. 3 is a block diagram showing further essential parts such as the tray 302 and the rising plate 304 in FIG. As shown in FIG. 3, the ground spring 10 has a shape bent along the layout of the grooves 301c shown in FIG. The side end portion 10 c is electrically connected to an electrical system such as the paper feed mechanism 200 in a state where the paper feed cassette 1 is inserted into the image forming apparatus 100. However, as shown in FIG. 1, the only part of the earth spring 10 that is lifted from the groove 301 c and protrudes from the bottom surface part 301 b is the tip part 10 a, and the tip part 10 a is in contact with the ascending plate 304 as shown in the figure. The state is maintained.

  The paper feed cassette 1 according to the present embodiment having the above-described configuration uses the ground spring 10 provided on the bottom surface portion 301b of the housing portion 301 to brake the fall of the rising plate 304.

  In the above configuration, the paper feed cassette 1 corresponds to the paper feed cassette of the present invention, the casing 301 corresponds to the casing of the present invention, and the rising plate 304 corresponds to the rising plate of the present invention. The tray 302 corresponds to the mounting plate of the present invention, the ground spring 10 corresponds to the ground spring of the present invention, and the tip end portion 10a corresponds to the buffer member of the present invention. Moreover, the opening part 20 is corresponded to the recessed part of this invention.

  Hereinafter, the operation of the sheet feeding cassette 1 according to the embodiment of the present invention will be described with reference to the configuration diagrams of FIGS. 1 to 3 and the explanatory diagrams of FIGS.

  Also in this embodiment, the operation of the paper feed cassette 1 is the same as that of the conventional example. That is, in the case of paper replenishment or the like, the paper feed cassette 1 is pulled out from the image forming apparatus 100. At this time, the connection between the end of the rotation shaft 305 of the input gear 307 and the actuator of the image forming apparatus 100 is released. As a result, the rotation shaft 305 is freely rotatable.

  On the other hand, as shown in FIG. 4, the tip portion 10 a of the earth spring 10 is in contact with the side of the rising plate 304 adjacent to the rotation shaft 305. The tip portion 10 a is elastic because it is bent from the other portion of the earth spring 10, and applies a constant urging force to the ascending plate 304.

  Therefore, when the rotation shaft 305 becomes rotatable, the ascending plate 304 rotates toward the bottom surface portion 301b along the direction of arrow E in FIG. 4, but due to the urging force from the tip portion 10a of the ground spring 10 That momentum will be relieved. As a result, as shown in the states (a), (b), and (c) of FIG. 5, the end portion 304 a of the rising plate 304 rotates while always contacting the back surface of the tray 302.

  That is, the tray 302 loses its support by the rising plate 304 and rotates by its own weight toward the bottom surface portion 301b. However, the support by the rising plate 304 is not completely lost as in the conventional example, and the tip of the ground spring 10 is not lost. The urging force from 10a acts as a drag force. For this reason, the tray 302 is gently rotated while being applied with an upward force (upwardly of the housing 301) by the ascending plate 304 and reaches the bottom surface 301b.

  Immediately before the rising plate 304 reaches the bottom surface portion 301b, the contact between the end portion 304a and the tray 302 is released, and the tray 302 collides with the bottom surface portion 301b due to free fall, but until then, the momentum of rotation is sufficiently eased. Therefore, the impact sound can be kept small.

  FIG. 6 shows a state when the tray 302 has completely reached the bottom surface portion 301b. The positional relationship between the tray 302 and the rising plate 304 is the same as that of the conventional example. However, when the rising plate 304 is in a state of landing on the bottom surface portion 301b, the tip portion 10a of the earth spring 10 is restrained by the rising plate 304 and the bottom surface portion. It sinks into the opening 20 of 301b.

  That is, since the tip end portion 10a of the earth spring 10 is allowed to escape from the opening 20, the folded state of the tray 302 and the rising plate 304 can be ensured as in the conventional example. In the present embodiment, the opening 20 is a through-hole that reaches the back side of the bottom surface portion 301b. However, it is sufficient that a space necessary for fitting the tip portion 10a is formed as a recess. It may be formed. 4 and 6, the tip portion 10a of the earth spring 10 is always in contact with the rising plate 304 in the movable range of the rising plate 304.

  Compared to the configuration of the conventional example using the spring 400 shown in FIG. 14, in the case of this embodiment, the ground spring 10, the rising plate 304, and the tray 302 are kept in contact with each other when the cassette is pulled out. Since the plate 304 and the tray 302 are rotated, the impact mitigation performance is less likely to vary with respect to the change in the weight of the tray 302.

  The ground spring 10 is a member conventionally used in the paper feed cassette 1, and the tip portion 10a can be obtained by a slight processing. In other words, the buffer member of the present invention is obtained as a configuration that also serves as the earth spring 10. Therefore, the installation in the paper feed cassette 1 is easy, and the installation location is not compressed.

  As described above, according to the paper feed cassette 1 according to the embodiment of the present invention, the front end portion 10a of the ground spring 10 disposed on the bottom surface portion 301b of the housing portion 301 is bent and brought into contact with the ascending plate 304. Yes. As a result, a constant urging force is applied to the rising plate 304, and when the pulling plate 304 is pulled out from the image forming apparatus 100, the rotation of the rising plate 304 and the rotation of the tray 302 that follows it are alleviated. It is possible to reduce the impact sound that occurs when the battery collides with the bottom surface portion 301 b of the housing portion 301.

  In the above description, the tip portion 10a of the ground spring 10 has been described as being in contact with the ascending plate 304 on the side adjacent to the rotating shaft 305 of the ascending plate 304, but the dotted line in FIG. As shown by, it is good also as a structure contact | abutted with the raise board 304 in the side near the edge part 304a. In this case, the length of the distal end portion 10a can be increased, and the urging force to the rising plate 304 can be increased.

  Moreover, although the shape of the front-end | tip part 10a was demonstrated as what curves cyclically | annularly toward the bottom face part 301b, as shown in FIG. 8, it is good also as what curves toward the raising board 304 side as reverse direction. . Further, the curved shape is not limited to an annular shape, and may be a hairpin shape or a rectangular shape. Moreover, it is good also as a structure which is not curving. In short, the tip of the ground spring of the present invention is not limited by its specific configuration.

  In the above description, the earth spring 10 has been described as being disposed in the groove 301 c formed in the bottom surface portion 301 b of the housing portion 301.

  FIG. 9A is a schematic plan view of a main part of the paper feed cassette 1 according to the first embodiment for explaining the layout of the ground spring 10, the groove 301 c and the rising plate 304. As shown in FIG. 9, the earth spring 10 is disposed in a groove 301c formed along the bent shape. A portion of the groove 301c that extends opposite to the rising plate 304 is formed along the axis of symmetry of the rising plate 304 that is orthogonal to the extending direction of the rotating shaft 305 of the rising plate 304. The tip 10a of the earth spring 10 is also arranged in this portion. However, the present invention is not limited to this, and a layout corresponding to the arrangement of a conventional earth spring may be used. For example, the groove 302c and the groove 303c may be provided at positions that are asymmetric with respect to the rising plate 304, for example. Alternatively, the groove 301c may be provided in a direction oblique to the rotation shaft 305. In short, the earth spring of the present invention is not limited by its specific arrangement.

  Further, the earth spring 10 can be fixed in the groove 301c at an edge of the groove 301c having a rectangular cross section, as illustrated in FIG. It shall be performed by the stop part 30 provided for every space | interval. When a force from the rising plate 304 is applied to the tip portion 10a, portions other than the tip portion 10a of the earth spring try to lift from the groove 301c by reaction, but the stopper 30 locks the earth spring 10 and lifts up. It is preventing.

  On the other hand, as shown in FIG. 9C, a groove 301d that is a parallelogram in section and does not have the stopper 30 may be used. In this case, the ground spring 10 is arranged by being inserted along the oblique wall surface of the groove 301d, but in use, the reaction of the urging force transmitted from the tip portion 10a is in a direction perpendicular to the bottom surface portion 301b. As a result, the ground spring 10 tries to float in a direction crossing the wall surface and is locked by the resultant groove 301d. In addition, the cross-sectional shape of the groove may be a U-shaped cross-section or a L-shaped cross-section, and the same effect can be obtained.

  As described above, the earth spring 10 may be fixed by an arbitrary method according to the shape and design of the paper feed cassette.

  In the above description, the shock-absorbing member of the present invention is described as using the earth spring 10, but the present invention is not limited to this. It may be provided as a separate member for a paper feed cassette having no ground. Moreover, you may make it provide the buffer member of this invention in the earth spring 10 further. In this case, a spring such as a coil spring or a leaf spring, or an elastic body such as silicon rubber may be used. In short, the shock-absorbing member of the present invention can be used in combination with the specific shape, configuration, or other members as long as it can always come into contact with the rising plate within the movable range of the rising plate, or independently. It is not limited by matters such as whether it is provided.

  In the above embodiment, the present invention has been described by taking the paper feed cassette 1 as an example. However, in the image forming apparatus 100 shown in FIG. An image forming apparatus that includes the paper device 120 as the paper feeding unit of the present invention and includes the paper feeding cassette 1 of the present invention is also included in the present invention.

  INDUSTRIAL APPLICABILITY The present invention has an effect of reliably reducing the impact sound generated when a cassette is pulled out, and is useful in a paper feed cassette, an image forming apparatus using the same, and the like.

FIG. 3 is a side view showing a configuration in the vicinity of the paper feeding device including the paper feeding cassette 1 according to the embodiment of the present invention. It is a perspective view which shows the principal part of the paper feed cassette 1 of embodiment of this invention. It is a perspective view which shows the further principal part of the paper feed cassette 1 of embodiment of this invention. It is explanatory drawing for demonstrating operation | movement of the paper feed cassette 1 of embodiment of this invention. It is explanatory drawing for demonstrating operation | movement of the paper feed cassette 1 of embodiment of this invention. It is explanatory drawing for demonstrating operation | movement of the paper feed cassette 1 of embodiment of this invention. It is a principal part side view for showing typically another example of composition of sheet feed cassette 1 of an embodiment of the invention. It is a principal part side view for showing typically another example of composition of sheet feed cassette 1 of an embodiment of the invention. (A) It is a typical principal part top view for demonstrating the layout of the paper feed cassette 1 of embodiment of this invention. (B) It is principal part sectional drawing by the AA straight line of Fig.9 (a). (C) It is principal part sectional drawing corresponding to FIG.9 (b) for showing the other structural example of the paper feed cassette 1 of embodiment of this invention. 1 is a diagram schematically illustrating a configuration of an image forming apparatus. It is a side view which shows the structure of the sheet feeder vicinity containing the sheet feeding cassette 300 by a prior art. It is explanatory drawing for demonstrating operation | movement of the paper feed cassette 300 by a prior art. It is explanatory drawing for demonstrating operation | movement of the tray 302 in the paper feed cassette 300 by a prior art. It is a figure which shows the structure for the shock absorption of the tray 302 by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feed cassette 10 Ground spring 10a Tip part 20 Opening part 30 Stop part 301 Case part 301a Wall part 301b Bottom part 302 Tray 304 Rising plate 304a End part 305 Rotating shaft

Claims (6)

A paper feed cassette for feeding paper to an image forming apparatus,
A casing provided so as to be freely inserted and removed from the image forming apparatus;
Provided in the casing, and when the casing is inserted into the image forming apparatus, the casing is rotated upward by the external force, and the casing is extracted from the image forming apparatus. In a state where the external force is released, a rising plate that rotates by its own weight toward the bottom surface of the housing part,
A mounting plate that mounts a sheet fed to the image forming apparatus on its main surface, which is inclined according to the rotation of the rising plate;
A paper feed cassette comprising: a buffer member that is always in contact with the rising plate in the rotation range of the rising plate and that reduces the rotational force of the rising plate when the external force is released. Having an earth spring disposed on the bottom surface of the housing part;
2. The sheet feeding cassette according to claim 1, wherein the buffer member is configured such that a tip of the earth spring protrudes from the bottom surface and abuts on the rising plate.   The paper feed cassette according to claim 2, wherein a tip of the earth spring is in contact with the rising plate on a side adjacent to a rotation shaft of the rising plate. The earth spring including the buffer member is disposed in a direction perpendicular to the rotation axis of the rising plate,
The paper feed cassette according to claim 2, wherein a tip of the earth spring is inclined in the same direction as the mounting plate and is in contact with the rising plate. The tip of the ground spring is curved in an annular shape toward the bottom surface of the housing part,
The paper feed cassette according to claim 2, wherein a concave portion for accommodating a tip of the earth spring is formed on a bottom surface of the casing portion. An image forming unit for forming an image on paper;
A paper feeding unit that feeds the paper to the image forming unit,
The image forming apparatus, wherein the sheet feeding unit includes the sheet feeding cassette according to claim 1.