JP2012246076A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus which can reduce unpleasant noise generated when a cassette is inserted in a configuration where the cassette is electrically grounded in an apparatus body.SOLUTION: A printer having a paper cassette d2 for accommodating sheets on which an image is formed, and an apparatus body having a cassette inserting path into which the paper cassette d2 can be inserted and metal base plates 14 and 15 which are provided on the cassette inserting path and which are electrically grounded, further has a ground spring 20 which is provided at the paper cassette d2 and can appear between a contact position where it can contact with the metal base plates 14 and 15 and an evacuation position where it is evacuated from the contact position, and a moving device 50 that puts the ground spring 20 at the contact position behind a predetermined position on the cassette inserting path, and puts the ground spring 20 at the evacuation position before the predetermined position.

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, or a facsimile machine.

  In general, an image forming apparatus includes a cassette that accommodates a sheet material on which an image is formed. The cassette is configured to be detachable from the apparatus main body, and the apparatus main body is provided with a cassette insertion path through which the cassette can be inserted. Therefore, after the user stores the sheet material in the cassette, the user feeds the cassette along the cassette insertion path and mounts the cassette on the apparatus main body, thereby replenishing the sheet material.

  By the way, in the process of feeding the sheet material from the cassette to the main body of the sheet, if charges are accumulated due to rubbing between the sheet materials, the sheet material is heavyly transported and defective image formation in the main body of the apparatus May be caused. Therefore, it is necessary to take an electrical ground in order to release static electricity in the cassette.

  In the following prior art document, when the cassette bottom plate is cut out at a position corresponding to an end portion that is a pivotal fulcrum of the intermediate plate that supports the sheet material, and the cassette is mounted at a predetermined position of the apparatus main body, A configuration is disclosed in which a grounding spring provided on the main body side and biased upward enters the cassette from the notched portion and comes into contact with the end of the middle plate to release static electricity to the outside of the cassette. Yes.

No. 4-9834

However, in the above configuration, the grounding spring and the cassette bottom plate are always rubbed during the cassette insertion process until the cassette is mounted on the apparatus main body. If it does so, the metal sound emitted by the said rubbing may be uncomfortable for some users.
On the other hand, in order to avoid the rubbing, it is possible to adopt means for changing the casing shape of the cassette or the apparatus main body. However, since the strength of the casing itself may be reduced, the casing shape is significantly changed. It ’s difficult.

  The present invention has been made in view of the above problems, and in adopting a structure in which the cassette is electrically grounded in the apparatus main body, image formation capable of reducing unpleasant sound generated when the cassette is inserted is formed. An object is to provide an apparatus.

In order to solve the above-described problems, the present invention provides a cassette that accommodates a sheet material on which an image is formed, a cassette insertion path into which the cassette can be inserted, and a cassette insertion path that is provided in the cassette insertion path and is electrically grounded. An image forming apparatus having a grounding unit, wherein the grounding member is provided in the cassette and can be moved in and out between a contact position capable of contacting the grounding unit and a retracted position retracted from the contact position. And a moving device that positions the grounding member at the contact position on the back side of the predetermined position in the cassette insertion path and positions the grounding member at the retracted position on the near side of the predetermined position; The structure of having is adopted.
By adopting this configuration, in the present invention, in the cassette insertion process, when the cassette reaches the back side from the predetermined position of the cassette insertion path, the grounding member provided in the cassette protrudes and is provided in the apparatus main body. Although it is possible to contact the grounding part, the grounding member is immersed in the cassette and cannot contact the grounding part provided in the main body of the device on the near side before reaching the predetermined position. And the grounding portion are not always rubbed, and the metal sound generated by the rub can be reduced.

In the present invention, the moving device includes a guide groove provided along the cassette insertion path, an engagement member provided in the cassette, which contacts the grounding member and engages the guide groove. The structure of having is adopted.
By adopting this configuration, in the present invention, when the cassette is inserted, the engaging member provided in the cassette is guided by the guide groove to move the grounding member to the contact position and the retracted position.

In the present invention, the grounding member is urged toward the retracted position, and the guide groove contacts the grounding member against the urging on the back side of the predetermined position. A configuration is adopted in which the engagement member is guided to a position to be positioned.
By adopting this configuration, in the present invention, in the cassette insertion path, the engagement member is positioned at the contact position against the urging at the back side from the predetermined position in the cassette insertion path, and is further in front of the predetermined position. On the side, the grounding member is located at the retracted position by the biasing.

In the present invention, the apparatus main body has a configuration in which a second grounding portion is provided on the near side of the predetermined position.
By adopting this configuration, in the present invention, when the cassette is inserted, the grounding member and the second grounding portion provided on the near side of the predetermined position do not come into contact with each other and are not rubbed.

  According to the present invention, in the cassette insertion process, the ground member on the cassette side and the ground portion on the apparatus main body are not always rubbed, so that unpleasant metal sound generated when inserting the cassette can be reduced.

1 is a schematic configuration diagram of a printer according to an embodiment of the present invention. 1 is a perspective view illustrating an appearance of a printer according to an embodiment of the present invention. It is a perspective view which shows the metal housing | casing and cassette guide of the apparatus main body in embodiment of this invention. It is a perspective view which shows the structure by the side of the bottom face of the metal housing | casing in embodiment of this invention. It is a perspective view which shows the paper feed cassette in embodiment of this invention. It is a perspective view which shows the principal part of the paper feed cassette in embodiment of this invention. It is a top view which shows the principal part of the paper feed cassette in embodiment of this invention. FIG. 4 is a perspective view illustrating a configuration of a grounding spring provided in a paper feed cassette in the embodiment of the present invention. It is a perspective view which shows the structure of the engaging member provided in the paper feed cassette in embodiment of this invention. It is a perspective view which shows the cassette guide in embodiment of this invention. It is a figure which shows the mode of the vertical motion of the grounding spring in embodiment of this invention. It is a figure which shows sectional drawing before the cassette insertion in embodiment of this invention, and its principal part enlarged view. It is a figure which shows the principal part enlarged view in the middle of cassette insertion in embodiment of this invention. It is a figure which shows sectional drawing after cassette insertion in the embodiment of this invention, and its principal part enlarged view.

  Hereinafter, an embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size. In the following description, an XYZ orthogonal coordinate system may be set, and the positional relationship of each member may be described with reference to this XYZ orthogonal coordinate system.

(Schematic configuration of image forming apparatus)
FIG. 1 is a schematic configuration diagram of a printer P according to an embodiment of the present invention.
The printer (image forming apparatus) P includes a discharge portion a, a toner cartridge storage portion b, an image forming portion c, and a paper portion d. Further, the printer P is provided with a transport unit e from a paper part d located at the lower part to a discharge part a located at the upper part.

  The discharge unit a is configured such that a sheet (sheet material) on which a predetermined image is formed is discharged through the transport unit e. The bottom surface of the discharge part a is inclined so that when a plurality of sheets are discharged, one end side is aligned and stacked.

  The toner cartridge storage section b can store a black toner (BK) toner cartridge b1, a yellow toner (Y) toner cartridge b2, a cyan toner (C) toner cartridge b3, and a magenta toner (M) toner cartridge b4. It is configured. The cartridges b1 to b4 are configured to be able to supply toner to the developing unit c2 of the image forming unit c.

  The image forming unit c includes a laser scanning unit c1, a developing unit c2, an intermediate transfer belt unit c3, a cleaning unit c4, a secondary transfer unit c5, and a fixing unit c6.

  Similarly to the known laser scanning unit, the laser scanning unit c1 includes a light beam generator that generates laser light, a polygon mirror that scans a light beam emitted from the light beam generator, and the polygon mirror. And an fθ lens that forms an image on the photosensitive drums 1a to 1d described later.

  The developing unit c2 develops the electrostatic latent images formed on the peripheral surfaces of the photosensitive drums 1a to 1d by supplying toner to the photosensitive drums 1a to 1d, and each color (BK, Y, Four developing units c21 corresponding to C, M) are provided.

  The photosensitive drums 1a to 1d are provided at predetermined intervals along the conveyance direction of the intermediate transfer belt unit c3. These photosensitive drums 1a to 1d are provided corresponding to the respective colors (BK, Y, C, M). Each of the photoconductive drums 1a to 1d is provided with a charger, a static eliminator, a cleaner, and the like, and an electrostatic latent image is generated on the charged drum peripheral surface using the laser scanning unit c1. A toner image is formed by the toner supplied from the toner cartridge housing portion b to the developing unit c2.

  The intermediate transfer belt unit c3 has an endless intermediate transfer belt (primary transfer belt) 2 composed of a laminated belt formed by laminating an elastic layer on a synthetic resin belt base. One end side (+ X side) of the intermediate transfer belt 2 is opposed to a part of the conveyance unit e provided on the one end side of the main body of the printer P along the vertical direction (Z direction), and the other end side. (−X side) is located on the other end side of the main body of the printer P, and is provided substantially horizontally. The intermediate transfer belt 2 is configured such that one end side is stretched around a drive roller 3 connected to a drive source (not shown) and the other end side is stretched around a tension roller 4.

  Primary transfer rollers 5 a to 5 d are provided at positions facing the photosensitive drums 1 a to 1 d of the intermediate transfer belt 2 with the intermediate transfer belt 2 interposed therebetween. The primary transfer rollers 5 a to 5 d are configured to be able to rotate as the intermediate transfer belt 2 moves. In addition to the driving roller 3 and the tension roller 4, the intermediate transfer belt 2 is supported by a conversion roller or an idling roller that changes the moving direction of the belt.

The cleaning unit c4 is provided on the tension roller 4 side, and is configured to remove the toner remaining on the intermediate transfer belt 2 using a blade or the like, and to discharge the removed toner to a waste toner bottle (not shown). ing.
The secondary transfer unit c5 includes a driving roller 3 described above and a secondary transfer roller 6 that faces the driving roller 3 and is disposed with the intermediate transfer belt 2 interposed therebetween.

  As described above, the secondary transfer roller 6 faces the drive roller 3 and is disposed with the intermediate transfer belt 2 interposed therebetween. The secondary transfer roller 6 is always provided to press the drive roller 3. Therefore, when the intermediate transfer belt 2 is moved (rotated) by the driving roller 3, the secondary transfer roller 6 can rotate along with the movement. When the sheet is conveyed via the conveying unit e, the secondary transfer roller 6 can be rotated while the sheet is interposed between the intermediate transfer belt 2 and the sheet is fixed to the fixing unit. It can be transported to the c6 side.

  The fixing unit c6 is provided in a part of the transport unit e on the downstream side of the secondary transfer unit c5, and a pair of sheets arranged so as to sandwich the paper transported through the transport unit e. Consists of rollers. The fixing unit c6 is configured so that the toner image on the sheet transferred by the secondary transfer unit c5 by being pressed and heated by the pair of rollers can be fixed on the sheet.

  The paper portion d includes a paper feed tray d1 provided so as to be openable and closable with respect to the apparatus main body 10 and a paper feed cassette (cassette) d2 provided so as to be drawable with respect to the apparatus main body 10. The sheet feeding tray d1 or the sheet feeding cassette d2 is configured to be able to supply sheets one by one to the transport unit e. The sheet feeding cassette d2 and the apparatus main body 10 will be described in detail later with reference to the drawings.

  The conveyance part e is provided from the paper part d located in the lower part to the discharge part a located in the upper part, and includes a plurality of conveyance rollers and a guide plate. The transport unit e is configured to transport the sheets supplied from the sheet unit d one by one toward the discharge unit a.

  In the printer P configured as described above, when the driving roller 3 is started and the intermediate transfer belt 2 starts to rotate, in the case of color printing, the laser scanning unit c1 applies to the photosensitive drums 1a to 1d. A laser beam corresponding to the image data is irradiated to form an electrostatic latent image, and a toner image of each color is formed by the supplied toner. The toner images of the respective colors are sequentially superimposed and transferred onto the intermediate transfer belt 2 to synthesize a color image. Next, the color image synthesized on the intermediate transfer belt 2 is transferred to a sheet by a secondary transfer unit c5, and then subjected to a fixing process by being pressurized and heated by a fixing unit c6. Finally, the paper on which the color image is printed is discharged to the discharge unit a.

(Structure of paper cassette and main unit)
FIG. 2 is a perspective view showing an appearance of the printer P according to the embodiment of the present invention. FIG. 3 is a perspective view showing the metal casing 11 and the cassette guide 12 of the apparatus main body 10 according to the embodiment of the present invention. FIG. 4 is a perspective view showing the configuration of the bottom surface side of the metal casing 11 in the embodiment of the present invention.

  As shown in FIG. 2, the paper feed cassette d <b> 2 is attached to the bottom of the apparatus main body 10. The paper feed cassette d2 is inserted into a cassette insertion path 13 (see FIG. 3) provided at the bottom of the apparatus main body 10, and is configured to be removable in the X-axis direction. That is, paper can be replenished by pulling out the paper feed cassette d2 toward the front side (−X side) in the X-axis direction, and the paper feed cassette d2 is inserted along the cassette insertion path 13 toward the back side (+ X side) in the X-axis direction. By doing so, it can be attached to the apparatus main body 10.

  As shown in FIG. 3, the cassette insertion path 13 is provided with a cassette guide 12 that supports the paper feed cassette d2 and guides it in the insertion direction (X-axis direction). The cassette guide 12 is fixed to the side wall portion of the metal casing 11 of the apparatus main body 10. Note that, unlike the metal housing 11, the cassette guide 12 is formed of a plastic frame. The configuration of the cassette guide 12 will be described in detail later with reference to the drawings.

  The metal casing 11 is formed in a substantially box shape, and a plurality of mounting holes for attaching the above-described various components are formed. As shown in FIG. 4, the metal casing 11 has two metal bottom plates 14 and 15 on the bottom surface side. The metal bottom plates 14 and 15 are each provided in a beam shape across both side wall portions of the metal casing 11 and are given a predetermined bend, so that the strength of the metal casing 11 is ensured. Yes.

The paper feed cassette d2 is disposed on the metal bottom plates 14 and 15 when mounted on the apparatus main body 10. That is, the metal bottom plates 14 and 15 are provided in the cassette insertion path 13 and are disposed so as to be accessible to the paper feed cassette d2. The metal bottom plates 14 and 15 are grounding portions that are electrically grounded.
Hereinafter, the metal bottom plate 14 arranged on the back side (+ X side) in the cassette insertion path 13 is the first grounding portion, and the metal bottom plate 15 arranged on the near side (−X side) in the cassette insertion path 13 is the second. It may be referred to as a grounding portion.

  FIG. 5 is a perspective view showing the paper feed cassette d2 in the embodiment of the present invention. FIG. 6 is a perspective view showing a main part of the paper feed cassette d2 in the embodiment of the present invention. FIG. 7 is a plan view showing a main part of the paper feed cassette d2 in the embodiment of the present invention. FIG. 8 is a perspective view showing the configuration of the ground spring 20 provided in the paper feed cassette d2 in the embodiment of the present invention. FIG. 9 is a perspective view showing a configuration of the engaging member 30 provided in the paper feed cassette d2 in the embodiment of the present invention.

As shown in FIG. 5, the paper feed cassette d <b> 2 has a grounding spring (grounding member) 20 that releases static electricity to the metal housing 11. The grounding spring 20 is provided on the back side of the intermediate plate 16 that supports the paper and on the back side (+ X side) in the insertion direction of the paper feed cassette d2.
As shown in FIG. 7, the ground spring 20 has a substantially U shape in plan view, and is arranged so that the U shape opening faces toward the + X side. Sides other than the + Y side of the ground spring 20 are fixed by a plurality of fixing pieces 17 provided on the bottom plate of the paper feed cassette d2.

As shown in FIGS. 6 and 8, a bent portion 21 having a substantially triangular shape with an apex angle facing downward is provided at the tip of the side on the + Y side of the ground spring 20. The side on the + Y side of the ground spring 20 is bent around the axis extending in the Y-axis direction with respect to the other side, and the bent portion 21 is normally positioned above the other side. It has a configuration (see FIGS. 6 and 8).
As shown in FIG. 7, the bottom plate of the sheet feeding cassette d2 is provided with a through-hole 18 at which the bent portion 21 can be exposed on the back side (−Z side) of the bottom plate at a position corresponding to at least the bent portion 21 in plan view. ing.

As shown in FIG. 6, the paper feed cassette d <b> 2 is provided with an engagement member 30 that contacts the upper side (+ Z side) of the bent portion 21 of the ground spring 20. The engaging member 30 functions as a moving device 50 that moves the ground spring 20 in cooperation with the cassette guide 12 described later.
The engaging member 30 has a base end portion 31 that is rotatably supported on an axis extending in the Y-axis direction on the bottom plate of the paper feed cassette d2, and a tip end portion 32 that can swing around the base end portion 31. (See FIGS. 6 and 9).

  The distal end portion 32 has a shape protruding on both sides in the Y-axis direction. The 1st convex part 33 which protrudes in the -Y side of the front-end | tip part 32 becomes a structure which contacts the upper side of the bending part 21, as shown in FIG. On the other hand, the second protrusion 34 protruding to the + Y side of the front end portion 32 is configured to protrude outward through the through hole 19 opened in the side wall portion of the sheet feeding cassette d2, as shown in FIG. . The through hole 19 is formed in a size that does not interfere with the movable second convex portion 34.

FIG. 10 is a perspective view showing the cassette guide 12 in the embodiment of the present invention.
The cassette guide 12 is provided along the cassette insertion path 13 as described above, and is configured to guide horizontally in the X-axis direction while supporting the side wall portion of the paper feed cassette d2. The cassette guide 12 is provided with a guide groove (guide groove) 40 for guiding the engaging member 30 provided in the paper feed cassette d2.

The guide groove 40 includes a first straight portion 41 provided on the front side (−X side) of the paper feed cassette d2 in the insertion direction and a second straight line provided on the back side (+ X side) of the paper feed cassette d2 in the insertion direction. Part 42, and an inclined part 43 that connects the first straight part 41 and the second straight part 42.
The first straight portion 41 is provided at a predetermined height in the Z-axis direction, and the second straight portion 42 is parallel to the first straight portion 41 and lower than the first straight portion 41 in the Z-axis direction. It is provided at a height.

The second protrusion 34 of the engagement member 30 engages with the guide groove 40. Therefore, according to the moving device 50 having the guide groove 40 and the engaging member 30 configured as described above, when the second convex portion 34 moves up and down along the guide groove 40 in the cassette insertion process, The grounding spring 20 that contacts the one convex portion 33 moves up and down.
FIG. 11 is a diagram illustrating the vertical movement of the ground spring 20 according to the embodiment of the present invention.

  FIG. 11A shows a ground spring when the engaging member 30 is engaged with the first linear portion 41 of the guide groove 40 or when the engaging member 30 is not yet engaged with the guide groove 40. It is a figure which shows the mode of 20. FIG. At this time, the bent portion 21 of the grounding spring 20 is immersed in the paper feed cassette d2, and is in a position where it cannot contact the metal bottom plates 14 and 15 as the grounding portion (hereinafter sometimes referred to as a retracted position). positioned.

  On the other hand, FIG. 11B is a diagram illustrating the state of the grounding spring 20 when the engaging member 30 is engaged with the second linear portion 42 of the guide groove 40. At this time, the bent portion 21 of the ground spring 20 protrudes to the back side of the bottom plate of the paper feed cassette d2, and is in a position where it can contact the metal bottom plates 14 and 15 that are the ground portions (hereinafter sometimes referred to as a contact position). positioned.

  According to the moving device 50 configured as described above, when the paper feed cassette d2 reaches the back side (+ X side) from the predetermined position of the cassette insertion path 13 in the cassette insertion process, the ground spring 20 provided in the cassette is It protrudes and can come into contact with the metal bottom plates 14 and 15 provided on the apparatus main body 10, but on the near side (−X side) reaching the predetermined position, the ground spring 20 is immersed in the paper feed cassette d <b> 2 and the apparatus main body. 10 cannot be contacted with the metal bottom plates 14, 15 provided in 10.

Here, the predetermined position of the cassette insertion path 13 means that the engaging member 30 provided in the sheet feeding cassette d2 is a connecting portion 44 between the inclined portion 43 of the guide groove 40 and the second linear portion 42 (see FIG. 10). Means the position where
As will be described later, the position of the connecting portion 44 of the present embodiment is set to a position (position on the + X side of the metal bottom plate 15) beyond the metal bottom plate 15 in the insertion direction (X-axis direction).

Next, a series of operations of the ground spring 20 in the cassette insertion process will be described with reference to FIGS.
FIG. 12 is a diagram showing a cross-sectional view before inserting a cassette and an enlarged view of a main part A1 thereof in the embodiment of the present invention. FIG. 13 is an enlarged view of a main part in the middle of cassette insertion in the embodiment of the present invention. FIG. 14 is a cross-sectional view after inserting the cassette and an enlarged view of the main part A2 thereof in the embodiment of the present invention.

As shown in FIG. 12A, when the paper feed cassette d2 is mounted on the apparatus main body 10, the paper feed cassette d2 is inserted along the cassette insertion path 13 in the X-axis direction.
As shown in FIG. 12B, the grounding spring 20 and the engaging member 30 are provided on the + X side of the paper feed cassette d2. When the grounding spring 20 reaches the metal bottom plate (second grounding part) 15 provided on the near side of the cassette insertion path 13, the engaging member 30 is not engaged with the guide groove 40 and is grounded. Since the spring 20 is in a state where no force is applied, the grounding spring 20 is located at the retracted position immersed in the paper feed cassette d2, and is not in contact with the metal bottom plate 15.

  As shown in FIG. 13, when the sheet feeding cassette d <b> 2 is further pushed forward, the engaging member 30 reaches the inclined portion 43 via the first straight portion 41 of the guide groove 40. When the engaging member 30 is engaged with the first linear portion 41, the non-contact state of the ground spring 20 is maintained as in FIG. Thereafter, when the engaging member 30 engages with the inclined portion 43 from the first linear portion 41, the height of the distal end portion 32 of the engaging member 30 gradually decreases, and in conjunction therewith, the bent portion 21 of the ground spring 20 However, it moves downward from the retracted position to the contact position against its urging force.

  As shown in FIG. 13, when the engaging member 30 is engaged with the inclined portion 43, the bent portion 21 of the ground spring 20 has already passed over the metal bottom plate 15. For this reason, when inserting the paper feed cassette, the bent portion 21 of the ground spring 20 and the metal bottom plate 15 provided on the near side do not come into contact with each other and are not rubbed. Therefore, an unpleasant metal sound is not generated when inserting the paper feed cassette d2.

As shown in FIG. 14A, when the sheet feeding cassette d2 is further pushed further to the back side thereafter, the engaging member 30 passes through the position (predetermined position) of the connecting portion 44 to the second linear portion 42. Then, the sheet feeding cassette d2 is mounted on the apparatus main body 10.
As shown in FIG. 14B, when the engaging member 30 is engaged with the second linear portion 42, the distal end portion 32 is lowered to the height of the proximal end portion 31, and the bent portion 21 of the ground spring 20 is It is located at a contact position protruding from the bottom side of the bottom plate of the paper feed cassette d2, and is in contact with a metal bottom plate (first grounding portion) 14 provided on the back side.

As shown in FIG. 14B, when the bent portion 21 of the ground spring 20 and the metal bottom plate 14 come into contact with each other and are electrically connected, the paper feed cassette d2 is electrically grounded. As a result, static electricity can be released from the paper feed cassette d2, and it is possible to prevent heavy paper transport and image formation defects in the apparatus main body 10.
Thus, the mounting of the paper feed cassette d2 to the apparatus main body 10 is completed.

  When the paper feed cassette d2 is extracted from the apparatus main body 10, the engaging member 30 is lifted by the biasing force of the ground spring 20 in the process from the second straight portion 42 to the inclined portion 43 and the first straight portion 41, and the connection is made. On the near side (−X side) with respect to the portion 44, the bent portion 21 of the ground spring 20 is located at the retracted position. Then, the bent portion 21 of the ground spring 20 and the metal bottom plate 15 do not come into contact with each other and are not rubbed. Therefore, an unpleasant metal sound is not generated when the paper feed cassette d2 is extracted.

  Therefore, according to the above-described embodiment, the paper feed cassette d2 that stores the paper on which an image is formed, the cassette insertion path 13 into which the paper feed cassette d2 can be inserted, and the cassette insertion path 13 are provided electrically. A printer P having a grounded metal bottom plate 14 and 15, and a contact position provided in the paper feed cassette d2 and capable of contacting the metal bottom plates 14 and 15, and retracted from the contact position. The grounding spring 20 that can move in and out with respect to the retracted position, and the grounding spring 20 at the contact position on the back side of the predetermined position in the cassette insertion path 13 and the grounding spring 20 on the near side of the predetermined position. By adopting a configuration in which the moving device 50 is positioned at the retracted position, the sheet feeding cassette d2 is located at a position higher than the predetermined position of the cassette insertion path 13. The ground spring 20 provided in the paper feed cassette d2 protrudes and can come into contact with the metal bottom plates 14 and 15 provided in the apparatus main body 10, but on the near side to the predetermined position, The ground spring 20 is immersed in the paper feed cassette d2 and cannot contact the metal bottom plates 14 and 15 provided in the apparatus main body 10.

  Therefore, according to the present embodiment, the grounding spring 20 on the paper feed cassette d2 side does not rub against the metal bottom plates 14 and 15 on the apparatus main body 10 side in the cassette insertion process, so the paper feed cassette d2 is inserted. The unpleasant metal sound that is emitted when performing the process can be reduced. Further, according to the present embodiment, it is possible to establish an electrical ground in the paper feed cassette d2 while maintaining the strength of the casing of the apparatus main body 10 without changing the shape.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above-described embodiment, the beam-shaped metal bottom plates 14 and 15 are described as examples of the grounding portion. However, the present invention is not limited to this configuration. For example, when the entire bottom surface side of the metal casing 11 is formed of a single metal plate, the metal plate may be used as the grounding portion. In this case, if the connection portion 44 is provided on the start end side of the cassette insertion path 13 as in the above-described embodiment, the area where the ground spring 20 and the metal plate are rubbed becomes long, so the connection portion 44 is inserted into the cassette. It is preferably provided on the terminal side of the path 13.

  Further, for example, in the above-described embodiment, the configuration in which the grounding member is provided with a spring property is described as an example. However, a spring member that biases the grounding member may be separately provided. Further, the shape of the grounding member is not limited to the shape as shown in FIG. 8, and can be changed as appropriate in relation to the installation space in the paper feed cassette d2.

  Further, for example, in the above embodiment, a printer is exemplified as the image forming apparatus, but the present invention is also applicable to an image forming apparatus such as a copying machine and a facsimile apparatus.

  P ... printer (image forming apparatus), d2 ... paper feed cassette (cassette), 10 ... apparatus main body, 11 ... metal casing, 12 ... cassette guide, 13 ... cassette insertion path, 14 ... metal bottom plate (grounding part), 15 ... Metal bottom plate (second grounding part), 20 ... Grounding spring (grounding member), 21 ... Bending part, 30 ... Engaging member, 40 ... Guide groove, 44 ... Connection part (predetermined position), 50 ... Moving device

Claims (4)

An image forming apparatus comprising: a cassette for storing a sheet material on which an image is formed; a cassette insertion path into which the cassette can be inserted; and an apparatus main body having a grounding portion provided in the cassette insertion path and electrically grounded. Because
A grounding member that is provided in the cassette and is capable of appearing and retracting between a contact position capable of contacting the grounding portion and a retracted position retracted from the contact position;
A moving device that positions the grounding member at the contact position on the back side of the predetermined position in the cassette insertion path and positions the grounding member at the retracted position on the near side of the predetermined position. An image forming apparatus. The mobile device is
A guide groove provided along the cassette insertion path;
The image forming apparatus according to claim 1, further comprising: an engaging member that is provided in the cassette and contacts the grounding member and engages with the guide groove. The grounding member is biased toward the retracted position;
The said guide groove guides the said engaging member to the position which positions the said grounding member in the said contact position against the said urging | biasing at the back | inner side rather than the said predetermined position. Image forming apparatus.   The image forming apparatus according to claim 1, wherein the apparatus main body includes a second grounding portion on a front side of the predetermined position.

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