JP2006154557A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device which can easily load or unload a paper feed cassette, without leaking noise, such as friction noise, to the outside. <P>SOLUTION: A sponge 70 is sandwiched between an opposed surface 73a (the 1st surface) of an upper peripheral portion 73, having a surface orthogonal to the direction to pull out the paper feed cassette 9 and an opposed surface 74a (the 2nd surface) of a pressing wall 74. Thus, friction noise is prevented by the sponge 70 from leaking to the outside through between an aperture 2a and the paper feed cassette 9. Moreover, the sponge 70 can be prevented from peeling or rubbing and wearing, during work to out the paper feed cassette 9. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus.

  In general, an image forming apparatus has an opening formed in a side surface of an apparatus main body case, and accommodates a sheet feeding cassette in which sheets are stacked so that the sheet feeding cassette can be pulled out through the opening. During the image forming operation, the sheets in the sheet feeding cassette are sent one by one to the sheet conveying path by the sheet feeding roller in the apparatus main body case, and the sheets are image-formed by the image forming unit while being conveyed by the respective conveying rollers. Then, the sheet is discharged to a discharge tray through a fixing device.

  By the way, in this type of image forming apparatus, it is necessary to provide a gap between the opening of the apparatus body case and the paper feed cassette so that the paper feed cassette can be smoothly attached and detached. Therefore, from the gap, the sound of the paper being transported rubs along the paper transport path, the sound of rubs with various rollers, and the sound when the paper is separated one by one by friction (hereinafter referred to as “scraping sound, etc.”). ") Is likely to leak from the gap.

In addition, in the image forming apparatus, as disclosed in Patent Document 1 below, a so-called S-shaped path in which a sheet is reversed and conveyed so as to be folded near the front side where a paper cassette is attached and detached. There is a method. In this case, there is a problem that rubbing sound or the like during the reversal conveyance is likely to leak from the gap between the opening and the paper feed cassette.
JP 2004-157463 A

  Here, in order to suppress the rubbing noise and the like, an elastic member such as a sponge is attached to the opening portion of the apparatus main body case or the sheet feeding cassette at a portion facing in the vertical direction in the gap between them. A method for shielding the light can be considered. However, the gap is provided to facilitate the attachment and detachment of the paper feed cassette. If the gap is closed with a sponge so as to sandwich the paper feed cassette in the vertical direction, the elastic member becomes stronger every time the paper feed cassette is attached and detached. There may arise a problem that the sealing property (soundproof property) is deteriorated due to rubbing and peeling or abrasion, and the paper feeding cassette cannot be smoothly attached and detached.

  The present invention has been completed based on the above-described circumstances, and provides an image forming apparatus capable of suppressing the leakage of a rubbing sound or the like while allowing a paper feed cassette to be smoothly attached and detached. The purpose is to do.

As means for achieving the above object, an image forming apparatus according to the invention of claim 1 includes a cassette for storing a recording medium and an opening opened to the outside, and the cassette is formed through the opening. And an apparatus main body having a cassette housing portion that detachably accommodates the apparatus main body, wherein the apparatus main body has a first surface having an angle with respect to a drawing direction of the cassette at a peripheral portion of the opening. The cassette is housed in the cassette housing portion, and at least the first surface of the peripheral portion of the opening overlaps with the first surface, and a second surface is formed at a portion facing the first surface. And at least one of the first surface and the second surface between the first surface and the second surface in a state where the cassette is accommodated in the cassette accommodating portion. And an elastic member sandwiched are provided.
The “recording medium” is not limited to a paper recording medium such as paper but may be a plastic recording medium such as an OHP sheet.
Further, the “image forming apparatus” may be not only a printing apparatus such as a printer (laser printer) but also a facsimile machine or a multi-function machine having a printer function and a scanner function.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the first surface and the second surface are surfaces orthogonal to a drawing direction of the cassette.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the opening is formed in a recessed portion with a step with respect to the outer surface of the apparatus main body, and the opening is in the recessed portion. The first surface is formed at a peripheral portion of the opening, and the elastic member is arranged on the first surface without protruding to the cassette side.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the elastic member is arranged on the second surface so as not to protrude toward the opening. And

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the first surface is a gap between the apparatus main body and the cassette in a peripheral portion of the opening. It is formed in the part which continues to.

  According to a sixth aspect of the present invention, in the image forming apparatus according to the fifth aspect, the first surface, the second surface, and the elastic member have a width that is at least equal to a width of a recording medium that can be stored in the cassette. It is characterized by that.

  According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects, the cassette housing portion resists a reaction force of the elastic member pressed in a state where the cassette is housed. And holding means for holding the cassette.

  According to an eighth aspect of the present invention, in the image forming apparatus according to the seventh aspect, the holding means is provided on an elastic locking piece projecting in the cassette housing portion and on the cassette side, and the cassette is accommodated therein. It is provided with the to-be-latched part engaged with the said elastic latching piece in the state where it met.

  According to a ninth aspect of the present invention, in the image forming apparatus according to the seventh or eighth aspect, a positioning projection for determining the position of the cassette with respect to the cassette accommodating portion is provided in one of the cassette accommodating portion and the cassette. On the other side, a positioning recess for engaging with the positioning projection is provided, the positioning projection and the positioning recess abut in a state where the cassette is held by the holding means, and the elastic member is the first surface And it positions so that it may be in the state which received the pressing force by the 2nd surface.

  A tenth aspect of the present invention is the image forming apparatus according to any one of the first to ninth aspects, wherein the recording medium is disposed in the apparatus main body at a position close to the opening and is stored in the cassette. A feeding unit that feeds the sheets while separating them one by one, a conveyance unit that folds and conveys the recording medium fed by the feeding unit to the side opposite to the opening, and the conveyance unit Image forming means for forming an image on a recording medium.

<Invention of Claim 1>
In the present invention, between the first surface on the apparatus main body side and the second surface on the cassette side that has an angle with respect to the cassette drawing direction (including an angle perpendicular to the drawing direction and an inclined angle). The elastic member is sandwiched. Thereby, it can suppress that the rub sound etc. from between an opening part and a cassette leak outside by an elastic member. Moreover, it is possible to suppress the elastic member from being peeled off or rubbed and worn during the drawer operation.

<Invention of Claim 2>
In the present invention, the first surface and the second surface are surfaces orthogonal to the cassette drawing-out direction. Therefore, the pinching force between the opening of the apparatus main body and the cover wall of the cassette can be efficiently applied to the elastic member as compared with the configuration in which the first surface and the second surface are inclined with respect to the pull-out direction. It is possible to improve the sealing performance of the gap.

<Invention of Claim 3>
In the present invention, the elastic member is configured to be disposed in the peripheral portion of the opening that is recessed with a step from the outer surface of the apparatus main body. Therefore, even when the cassette is taken out, the elastic member is difficult to see from the outside, and a reduction in the design of the entire apparatus can be avoided. Further, since the elastic member is arranged on the first surface without protruding to the cassette side, it can be prevented that the elastic member comes into contact with the cassette and is peeled off when the cassette is pulled out.

<Invention of Claim 4>
In the present invention, since the elastic member is arranged without protruding to the opening side on the second surface, it is possible to prevent the elastic member from coming off in contact with the apparatus main body when the cassette is pulled out. Further, in combination with the configuration of claim 3, if the elastic member is provided on both the first surface and the second surface, the sealing performance of the gap can be further improved.

<Invention of Claims 5 and 6>
When the image forming apparatus is of a type that picks up a recording medium on the opening side, the recording medium in the cassette is fed into the portion of the peripheral portion of the opening that is connected to the gap between the apparatus main body and the cassette. It is considered that a large rubbing sound or the like leaks from this portion because it is close to the transport route to be transported. Therefore, in the present invention, the first surface is formed in that portion, and the elastic member is sandwiched between the second surface. Further, rubbing noise or the like is mainly generated within the width of the recording medium (the width in the direction perpendicular to the conveyance path). Accordingly, it is desirable that the widths of the first surface, the second surface, and the elastic member be at least equal to or larger than the width of the recording medium that can be stored in the cassette.

<Inventions of Claims 7 and 8>
According to the present invention, the cassette is held and accommodated in the apparatus main body while the elastic member is sandwiched and pressed between the first surface and the second surface. Therefore, the sealing performance by the elastic member can be improved. In addition, if the first surface and the second surface are configured to be orthogonal to the pulling direction as in the second aspect, the holding force by the holding means is applied to the elastic member as compared with the inclined configuration. It can be used efficiently to maintain the state.

<Invention of Claim 9>
According to this configuration, the positioning protrusion and the positioning recess are in contact with each other when the elastic member receives the pressing force while the cassette is held by the holding means, and the cassette moves further to the back side of the cassette housing portion. Is regulated. Therefore, it is possible to prevent the elastic member from being damaged by being pushed more strongly than necessary when the cassette is accommodated.

<Invention of Claim 10>
In the present invention, the rubbing sound of the feeding means and the conveying means is likely to leak from the opening gap. Therefore, the present invention is particularly effective for such a configuration.

An embodiment of the present invention will be described with reference to FIGS.
1. 1 to 3 are perspective views showing the external appearance of a laser printer 1 as an image forming apparatus of the present invention. 1 shows a state in which the paper feed cassette 9 is accommodated and the front cover 7 is closed, and FIG. 2 shows a state in which the paper feed cassette 9 is pulled out. In the following description, the side where the front cover 7 is provided in the laser printer 1 is referred to as “front side”, and the opposite side is referred to as “rear side”. The laser printer 1 with the paper cassette 9 removed corresponds to the “apparatus body 1a” of the present invention.

  As shown in FIG. 1, the laser printer 1 has a box shape as a whole, and is provided with a paper discharge tray 53 on which the printed (image-formed) paper 3 is discharged. A front cover 7 that is opened and closed when the process cartridge 20 is replaced, for example, is rotatably provided on one side surface (front surface) of the laser printer 1. Under the front cover 7, a paper feed cassette 9 that accommodates the paper 3 before printing is provided so that it can be pulled out from the front side (see FIG. 2).

2. Internal Configuration of Laser Printer FIG. 3 is a side cross-sectional view showing a main part of the laser printer 1. The laser printer 1 includes a main body casing 2, a feeder unit 4 for feeding paper 3 as a recording medium (sheet material) accommodated in the main body casing 2, and a fed paper 3. An image forming unit 5 (corresponding to the “image forming unit” of the present invention) for forming an image is provided.

(1) Main Body Casing An attachment / detachment opening 6 for attaching / detaching a process cartridge 20 described later is formed on one side wall of the main body casing 2, and a front cover 7 for opening / closing the attachment / detachment opening 6 is provided. ing. The front cover 7 is rotatably supported by a cover shaft 7a inserted through the lower end portion thereof. As a result, when the front cover 7 is closed around the cover shaft 7a, as shown in FIG. 1, the attachment / detachment port 6 is closed by the front cover 7, and when the front cover 7 is opened with the cover shaft 7a as a fulcrum (when tilted, ), The attachment / detachment opening 6 is opened, and the process cartridge 20 can be attached to / detached from the main casing 2 through the attachment / detachment opening 6.

(2) Feeder unit The feeder unit 4 has an opening 2a formed on the front surface of the bottom in the main body casing 2, and has a cassette housing unit 4a capable of housing the paper feed cassette 9 through the opening 2a. (See also FIG. 2). The feeder unit 4 includes a sheet feeding cassette 9 detachably accommodated in the cassette accommodating unit 4 a, a separation roller 10 and a separation pad 11 provided above the front end of the sheet feeding cassette 9, and a separation roller 10. And a paper feed roller 12 provided on the rear side (upstream in the conveyance direction of the paper 3 with respect to the separation pad 11). The separation roller 10, the separation pad 11, and the paper feed roller 12 correspond to the “feeding unit” of the present invention.

  In addition, the feeder unit 4 is disposed opposite to the paper dust removing roller 8 disposed opposite to the front upper side of the separating roller 10 (on the downstream side in the conveyance direction of the sheet 3 with respect to the separating roller). A counter roller 13 is provided. Then, the conveyance path of the paper 3 is folded back in the U-shape from the vicinity of the arrangement of the paper dust removing roller 8, and further below the process cartridge 20 on the downstream side in the conveyance direction from a pair of rollers. The registration roller 14 is provided. The paper dust removing roller 8, the opposing roller 13, and the registration roller 14 correspond to the “conveying means” of the present invention.

  Inside the paper feed cassette 9 is provided a paper pressing plate 15 on which the paper 3 can be stacked. The sheet pressing plate 15 is supported at the rear end so as to be swingable, so that the front end is disposed below, the mounting position along the bottom plate 16 of the sheet feeding cassette 9 and the front end are disposed above. It can be swung to an inclined supply position.

  A lever 17 for lifting the front end portion of the paper pressing plate 15 upward is provided at the front end portion of the paper feed cassette 9. The lever 17 is supported at a position below the front end portion of the paper pressing plate 15 so that the rear end portion is swingably supported by the lever shaft 18, and the front end portion of the lever 17 is lying on the bottom plate 16 of the paper feed cassette 9. The portion can swing between the inclined posture in which the paper pressing plate 15 is lifted. When a rotational driving force is input to the lever shaft 18, the lever 17 rotates counterclockwise in the figure with the lever shaft 18 as a fulcrum, and the front end of the lever 17 lifts the front end of the paper pressing plate 15. The pressing plate 15 is moved to the supply position.

  When the paper pressing plate 15 is positioned at the supply position, the paper 3 on the paper pressing plate 15 is pressed by the paper feed roller 12 and is rotated between the separation roller 10 and the separation pad 11 by the rotation of the paper feed roller 12. Paper feeding is started toward the separation position.

  On the other hand, when the paper feed cassette 9 is detached from the apparatus main body 1a, the front end of the paper pressing plate 15 moves downward due to its own weight, and the paper pressing plate 15 is positioned at the placement position. When the paper pressing plate 15 is positioned at the mounting position, the paper 3 can be stacked on the paper pressing plate 15. The separation pad 11, the paper dust removing roller 8, the paper pressing plate 15 and the lever 17 are provided in the paper feed cassette 9, and the paper feed roller 12, the separation roller 10, the opposing roller 13 and the registration roller 14 are the apparatus main body 1a. Is provided.

  The sheet 3 fed toward the separation position by the sheet feeding roller 12 is rolled and fed one by one when it is sandwiched between the separation roller 10 and the separation pad 11 by the rotation of the separation roller 10. Is done. The fed paper 3 is folded along the U-shaped transport path 56. More specifically, the fed paper 3 is first conveyed upward between the separation roller 10 and the separation pad 11, and further passed between the paper dust removing roller 8 and the opposing roller 13. Here, after the paper dust is removed, it is conveyed to the registration roller 14.

  The registration roller 14 conveys the sheet 3 to a transfer position between the photosensitive drum 29 and the transfer roller 32 (to be described later) and to transfer the toner image on the photosensitive drum 29 to the sheet 3 after registration.

(3) Image Forming Unit The image forming unit 5 includes a scanner unit 19, a process cartridge 20, a fixing unit 21, and the like.
(A) Scanner unit The scanner unit 19 is provided in the upper part of the main casing 2 and includes a laser light source (not shown), a polygon mirror 22 that is driven to rotate, an fθ lens 23, a reflecting mirror 24, a lens 25, a reflecting mirror 26, and the like. ing. The laser beam based on the image data emitted from the laser light source is deflected by the polygon mirror 22 as shown by the alternate long and short dash line, passes through the fθ lens 23, and then the optical path is turned back by the reflecting mirror 24. After passing, the optical path is further bent downward by the reflecting mirror 26, so that the surface of a photosensitive drum 29 (to be described later) of the process cartridge 20 is irradiated.

(B) Process Cartridge The process cartridge 20 is detachably attached to the apparatus main body 1 a below the scanner unit 19. The process cartridge 20 includes an upper frame 27 and a lower frame 28 formed separately from the upper frame 27 and combined with the upper frame 27 as a casing. The process cartridge 20 includes a photosensitive drum 29 as an image carrier, a scorotron charger 30 as a charging unit, a developing cartridge 31, a transfer roller 32 as a transfer unit, and a cleaning brush 33 in a housing. .

  The photosensitive drum 29 has a cylindrical shape, the outermost layer is formed of a positively chargeable photosensitive layer made of polycarbonate or the like, and an axial center of the drum main body 34 along the longitudinal direction of the drum main body 34. A metal drum shaft 35 is provided as an extending shaft. The drum shaft 35 is supported by the upper frame 27, and the drum main body 34 is rotatably supported by the drum shaft 35, so that the photosensitive drum 29 is rotatable about the drum shaft 35 in the upper frame 27. Is provided.

  The scorotron charger 30 is supported by the upper frame 27, and is disposed opposite to the photosensitive drum 29 at a predetermined interval so as not to contact the photosensitive drum 29 at an obliquely upper rear side of the photosensitive drum 29. The scorotron charger 30 is provided between the discharge wire 37 and the photosensitive drum 29, and is disposed between the discharge wire 37 and the photosensitive drum 29 so as to face the photosensitive drum 29 at a predetermined interval. And a grid 38 for controlling the amount. In the scorotron charger 30, a bias voltage is applied to the grid 38 and at the same time, a high voltage is applied to the discharge wire 37 to cause corona discharge of the discharge wire 37, so that the surface of the photosensitive drum 29 is uniformly positive. Can be charged.

  The developing cartridge 31 includes a box-shaped storage case 60 whose rear side is opened, and is detachably attached to the lower frame 28. In the developing cartridge 31, a toner storage chamber 39, a toner supply roller 40, a developing roller 41, and a layer thickness regulating blade 42 are provided.

The toner storage chamber 39 is formed as an internal space on the front side of the storage case 60 partitioned by the partition plate 43. The toner storage chamber 39 is filled with a positively chargeable nonmagnetic one-component toner T as a developer. Examples of the toner T include polymerizable monomers such as styrene monomers such as styrene, and acrylic monomers such as acrylic acid, alkyl (C1 to C4) acrylate, and alkyl (C1 to C4) methacrylate. A polymerized toner obtained by copolymerizing the toner by suspension polymerization or the like is used. Such a polymerized toner has a substantially spherical shape, has extremely good fluidity, and can achieve high-quality image formation.
Such a toner is blended with a colorant such as carbon black, wax, and the like, and an external additive such as silica is added to improve fluidity. The average particle size of the toner is about 6 to 10 μm.

  In the toner storage chamber 39, an agitator 44 supported by a rotation shaft 55 provided in the center is provided. The agitator 44 is rotationally driven by the input of power from a motor (not shown). When the agitator 44 is driven to rotate, the toner T in the toner storage chamber 39 is agitated and discharged toward the toner supply roller 40 from the opening 45 communicating in the front-rear direction below the partition plate 43. Further, window members (not shown) are mounted on the left and right side walls of the storage case 60 in regions corresponding to the toner storage chambers 39, respectively. Each window member is cleaned by a wiper that is held by and interlocked with the agitator 44. The main body casing 2 is provided with a light emitting element (not shown) outside the one window member and a light receiving element (not shown) outside the other window member, and is emitted from the light emitting element and accommodated in the housing case. Detection light that has passed through 60 is detected by a light receiving element, and the presence or absence of toner T is determined according to the output value.

  The toner supply roller 40 is disposed on the rear side of the opening 45 and is rotatably supported by the developing cartridge 31. The toner supply roller 40 is configured by covering a metal roller shaft with a roller made of a conductive foam material. The toner supply roller 40 is rotationally driven by power input from a motor (not shown).

  The developing roller 41 is rotatably supported by the developing cartridge 31 in a state in which the developing roller 41 is in contact with the toner supplying roller 40 so as to be compressed on the rear side of the toner supplying roller 40. The developing roller 41 is opposed to and contacts the photosensitive drum 29 in a state where the developing cartridge 31 is mounted on the lower frame 28. The developing roller 41 is configured by covering a metal roller shaft 41a with a roller made of a conductive rubber material. The roller shaft 41a projects from the side surface of the developing cartridge 31 outward in the width direction perpendicular to the front-rear direction at the front end portion of the developing cartridge 31. In the roller of the developing roller 41, the surface of a roller body made of conductive urethane rubber or silicone rubber containing carbon fine particles or the like is coated with a coating layer of urethane rubber or silicone rubber containing fluorine. A developing bias is applied to the developing roller 41 during development. The developing roller 41 is rotationally driven in the same direction as the toner supply roller 40 by the input of power from a motor (not shown).

  The layer thickness regulating blade 42 includes a pressing portion 47 having a semicircular cross section made of insulating silicone rubber at the tip of a blade body 46 made of a metal leaf spring material. The layer thickness regulating blade 42 is supported by the developing cartridge 31 above the developing roller 41, and the pressing portion 47 is pressed onto the developing roller 41 by the elastic force of the blade body 46.

  The toner T discharged from the opening 45 is supplied to the developing roller 41 by the rotation of the toner supply roller 40. At this time, the toner T is positively frictionally charged between the toner supply roller 40 and the developing roller 41. The toner T supplied onto the developing roller 41 enters between the pressing portion 47 of the layer thickness regulating blade 42 and the developing roller 41 as the developing roller 41 rotates, and forms the developing roller as a thin layer with a constant thickness. 41 is carried.

  The transfer roller 32 is rotatably supported by the lower frame 28. When the upper frame 27 and the lower frame 28 are combined, the transfer roller 32 is opposed to and contacts the photosensitive drum 29 in the vertical direction. They are arranged to form a nip therebetween. The transfer roller 32 is configured by covering a metal roller shaft with a roller made of a conductive rubber material. A transfer bias is applied to the transfer roller 32 during transfer. The transfer roller 32 is rotationally driven in the opposite direction to the photosensitive drum 29 by the input of power from a motor (not shown).

  The cleaning brush 33 is attached to the lower frame 28, and is arranged to face and contact the photosensitive drum 29 on the rear side of the photosensitive drum 29 in a state where the upper frame 27 and the lower frame 28 are combined. ing.

  The surface of the photosensitive drum 29 is first uniformly charged positively by the scorotron charger 30 as the photosensitive drum 29 rotates, and then exposed by high-speed scanning of the laser beam from the scanner unit 19. An electrostatic latent image corresponding to the image to be formed is formed.

  Next, the electrostatic charge formed on the surface of the photosensitive drum 29 when the positively charged toner carried on the developing roller 41 comes into contact with the photosensitive drum 29 by the rotation of the developing roller 41. The latent image is supplied to an exposed portion of the surface of the photosensitive drum 29 that is uniformly positively charged and exposed to a laser beam and having a lowered potential. As a result, the electrostatic latent image on the photosensitive drum 29 is visualized, and a toner image by reversal development is carried on the surface of the photosensitive drum 29.

Thereafter, as shown in FIG. 1, the toner image carried on the surface of the photosensitive drum 29 is passed through the transfer position between the photosensitive drum 29 and the transfer roller 32 by the sheet 3 conveyed by the registration roller 14. In the meantime, the image is transferred to the paper 3 by a transfer bias applied to the transfer roller 32. The sheet 3 on which the toner image is transferred is conveyed to the fixing unit 21.
The transfer residual toner remaining on the photosensitive drum 29 after the transfer is collected by the developing roller 41. Further, paper dust from the paper 3 adhering to the photosensitive drum 29 after the transfer is collected by the cleaning brush 33.

(C) Fixing Unit The fixing unit 21 is provided on the rear side of the process cartridge 20, and includes a fixing frame 48, and a heating roller 49 and a pressure roller 50 in the fixing frame 48.

  The heating roller 49 includes a metal tube whose surface is coated with a fluororesin, and a halogen lamp for heating in the metal tube, and is rotated by input of power from a motor (not shown). On the other hand, the pressure roller 50 is disposed opposite the heating roller 49 so as to press the heating roller 49. The pressure roller 50 is configured by covering a metal roller shaft with a roller made of a rubber material, and is driven in accordance with the rotational drive of the heating roller 49.

  In the fixing unit 21, the toner transferred onto the paper 3 at the transfer position is thermally fixed while the paper 3 passes between the heating roller 49 and the pressure roller 50. The sheet 3 on which the toner is fixed is conveyed to a sheet discharge path 51 that extends in the vertical direction toward the upper surface of the main casing 2. The sheet 3 conveyed to the sheet discharge path 51 is discharged onto a sheet discharge tray 53 formed on the upper surface of the main body casing 2 by a sheet discharge roller 52 provided on the upper side.

3. Configuration for Soundproofing (1) Sponge Arrangement Position As shown in FIG. 3, a part of the U-shaped transport path 56 is fed in a state where the paper feed cassette 9 is accommodated in the cassette accommodating portion 4 a. The separation pad 11 and the paper dust removing roller 8 on the cassette 9 side, and the separation roller 10 and the opposing roller 13 on the apparatus main body 1a side are formed. The transport path 56 is connected to a gap S between the upper portion on the front side of the paper feed cassette 9 and the main body casing 2. The gap S secures a space necessary for smoothly opening and closing the front cover 7 around the cover shaft 7a. Accordingly, in the process of transporting the paper 3, the rubbing sound of the paper 3 transported between the separation roller 10 and the separation pad 11 and between the paper dust removing roller 8 and the opposing roller 13 leaks from the gap S.

  Therefore, in this embodiment, the sponge 70 is provided so as to close the gap S. FIG. 4 is a partial side view showing a portion of the main casing 2 where the upper peripheral portion 73 of the opening 2 a is formed and the paper feed cassette 9. 5 and 6 are perspective views (No. 1 and No. 2).

  Specifically, as shown in FIGS. 2 and 3, the front end of the paper feed cassette 9 is a cover that covers the entire periphery of the opening 2 a from the front in a state of being accommodated in the cassette accommodating portion 4 a. A wall 9a is provided integrally. The cover wall 9a is formed in a shape that almost completely covers the left and right peripheral edge portions 71 and the lower peripheral edge portion 72 (see FIG. 2) of the opening 2a from the front, and the above-mentioned rubbing sound does not leak so much.

  On the other hand, the cover wall 9a is shaped so as to cover the upper peripheral portion 73 of the opening 2a from the front while leaving a clearance S between the lower end portion of the front cover 7 positioned above. As shown in FIGS. 2 to 4, the cover wall 9a has a lateral width of the conveyance path 56 (the width of the paper 3 that can be stored in the paper feed cassette 9. For example, the shorter width of A4 or letter size, FIG. A pressing wall 74 having a slightly wider width (width W1 shown in FIG. 5) than the width W2 shown in FIG.

  On the other hand, the upper peripheral edge portion 73 of the opening 2a, which is located behind the front cover 7 on the apparatus main body 1a side, has a width W1 slightly wider than the lateral width W2 of the transport path 56, and The lower end portion is covered from the front by the upper end portion of the pressing wall 74 in the drawing direction of the paper feed cassette 9 (the left-right direction in FIG. 3). Each of the facing surfaces 73a and 74a (corresponding to the “first surface” and “second surface” of the present invention) between the upper peripheral edge portion 73 and the pressing wall 74 is a surface orthogonal to the pulling-out direction. For example, an adhesive is attached to the sponge 70 over the entire length of each facing surface 73a.

  As shown in FIGS. 4 to 6, the sponge 70 is pressed between the opposing surfaces 73 a and 74 a and elastically deformed in a state in which the paper feed cassette 9 is accommodated in the cassette accommodating portion 4 a, whereby the gap S is formed. It is blocked and leakage such as rubbing noise can be prevented. The sponge 70 is arranged so as not to protrude downward from the facing surface 73a. In short, when the paper feed cassette 9 is attached or detached, it is arranged so as not to interfere with each part of the paper feed cassette 9.

(2) Cassette lock mechanism In this embodiment, when the paper feed cassette 9 is housed in the cassette housing portion 4a, the paper cassette 9 is held in the cassette housing portion 4a against the reaction force of the pressed sponge 70. Holding means is provided. FIG. 7 is a perspective view showing a pair of inner wall plates 80, 80 arranged as a frame in the main body casing 2 so as to sandwich the cassette housing portion 4 a from the left-right direction. FIG. 8 is a plan view of the paper feed cassette.

  As shown in FIG. 7, guide grooves 81, 81 for guiding the process cartridge 20 are formed in the upper part of the opposing surfaces of the pair of inner wall plates 80, 80 so as to continue to the attachment / detachment opening 6. Further, a guide rib 82 for guiding the paper feed cassette 9 to the cassette housing portion 4a (a guide rib 82 of the inner wall plate 80 on the back side of the paper surface in the figure) is provided at the lower part of the opposing surface of the pair of inner wall plates 80, 80. (Only shown) extends along the pull-out direction. The inner wall plates 80, 80 can be pivoted between a position protruding toward the inside of the cassette housing 4 a and a position retracted in each inner wall plate 80 at a portion near the rear end of the lower portion of the opposing surface. The locking pieces 84 are supported by the spring 83 and biased toward the protruding posture by a spring 83 as biasing means (see also FIG. 8).

  In contrast, on the sheet cassette 9 side, engaged portions 85 that engage with the respective locking pieces 84 are provided on the left and right side surfaces, respectively. As shown in FIG. 8, each engaged portion 85 is formed in a mountain shape when viewed from above. When the paper feed cassette 9 is mounted in the cassette housing portion 4a, each engaged portion 85 guides each locking piece 84 from the projected position to the retracted position by the rear inclined surface 85a.

  Further, since the paper feed cassette 9 is inserted into the back side of the cassette housing portion 4a, the front surface of each engaged portion 85 is inclined by the fact that each locking piece 84 gets over the tip end portion of each engaged portion 85. It returns to the projected position guided by the 85b side. The slope 85b on the front side is steeper than the slope 85a on the rear side. In this way, the paper feed cassette 9 is held by the apparatus main body 1 a against the reaction force of the sponge 70 by the engagement between the locking pieces 84 and the engaged portions 85.

(3) Positioning Mechanism As shown in FIG. 8, cylindrical positioning projections 86, 86 project from the side surface of the front end side of the sheet feeding cassette 9. On the other hand, as shown in FIG. 7, the left and right peripheral edge portions 71 of each inner wall plate 80 have positioning recesses that engage with the positioning protrusions 86 in a state where the paper feed cassette 9 is stored in the cassette storage portion 4 a. 87 are formed. Each positioning projection 86 and each positioning recess 87 are in contact with each other in a state in which each locking piece 84 and each engaged portion 85 are engaged, and the engaging force of each positioning projection 86 and each positioning recess 87. The sheet feeding cassette 9 is positioned with respect to the apparatus main body 1a against the reaction force of the sponge 70.

4). Effects of the present embodiment (1) In the present embodiment, the facing surface 73a (first surface) of the upper peripheral edge portion 73 having a surface orthogonal to the drawing direction of the paper feed cassette 9 and the facing surface 74a of the pressing wall 74 The sponge 70 is sandwiched between the second surface and the second surface. Thereby, it is possible to suppress a rubbing sound or the like from between the opening 2a and the sheet feeding cassette 9 from leaking to the outside by the sponge 70. In addition, it is possible to prevent the sponge 70 from being peeled off or rubbed and worn during the drawing operation of the paper feed cassette 9.
(2) Further, the facing surface 73 a and the facing surface 74 a are surfaces orthogonal to the pulling-out direction of the sheet feeding cassette 9. Therefore, the pinching force between the opening 2a of the apparatus main body 1a and the cover wall 9a of the sheet feeding cassette 9 can be efficiently compared with the configuration in which the facing surface 73a and the facing surface 74a are inclined with respect to the pull-out direction. It can be given to the sponge 70 and the sealing property of the gap S can be enhanced.

(3) The sponge 70 is configured to be disposed on the upper peripheral edge portion 73 recessed from the main body casing 2 with a step. Therefore, even when the paper feed cassette 9 is taken out, the sponge 70 is difficult to see from the outside, and the design of the entire apparatus can be prevented from being lowered (see FIG. 2). Further, since the sponge 70 is arranged so as not to protrude from the sheet feeding cassette 9 side on the facing surface 73a, it is possible to prevent the sheet feeding cassette 9 from coming into contact with the sheet feeding cassette 9 and being detached when the sheet feeding cassette 9 is attached or detached.
(4) Further, since the paper feed cassette 9 is held by the apparatus main body 1 a against the reaction force of the sponge 70 due to the engagement between the locking pieces 84 and the engaged portions 85, the sealing by the sponge 70 is performed. Can be improved. In addition, in the present embodiment, since the facing surface 73a and the facing surface 74a are surfaces orthogonal to the pulling direction of the sheet feeding cassette 9, the holding force by the holding means can be efficiently increased compared to the configuration inclined with respect to the pulling direction. It can be used for a pressing force of 70.

  (5) The positioning projection 86 and the positioning recess 87 are in contact with each other when the sponge 70 receives a pressing force while the sheet feeding cassette 9 is held by the holding means, and the sheet feeding cassette 9 is more than the cassette housing portion 4a. The movement to the back side of is restricted. Therefore, it is possible to prevent the sponge 70 from being damaged by being pushed more strongly than necessary when the paper feed cassette 9 is accommodated.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In the above embodiment, the sponge 70 is provided on the facing surface 73a of the upper peripheral edge portion 73 as the first surface. However, the present invention is not limited to this, and the facing surface 74a of the pressing wall 74 as the second surface. The structure provided in the side or both surfaces of the opposing surface 73a and the opposing surface 74a may be sufficient. In the case where it is provided on the facing surface 74a side, it is desirable to provide a sponge so as not to protrude from the facing surface 74a to the apparatus main body 1a side (so as not to interfere). Moreover, if it provides in both the opposing surface 73a and the opposing surface 74a, the sealing performance of the clearance gap S can be improved more.

  (2) In the above-described embodiment, the facing surface 73a and the facing surface 74a are surfaces that are orthogonal to the pulling direction, but are not limited thereto, and may be inclined surfaces. Further, they may be the same angle or different angles with respect to the drawing direction. In short, it is only necessary that the respective angles are such that the sponge 70 can be sandwiched and pressed in the pulling-out direction of the paper feed cassette 9.

  (3) In the above embodiment, the so-called S-shaped path type laser printer 1 having the U-shaped transport path 56 is taken as an example. However, the present invention is not limited to this, and has other transport paths. Also, the effects of the present invention can be obtained. However, in the case where the paper is folded and conveyed close to the gap S between the paper feed cassette 9 and the opening 2a as in the above embodiment, the rubbing sound or the like leaks particularly from the gap S, so that it is particularly effective.

  (4) The sponge 70 has been described as an example of the elastic member. However, the elastic member is not limited thereto, and may be rubber or a film as long as it is an elastic member.

  (5) Moreover, the structure which distribute | arranges an elastic member over the perimeter of the peripheral part of the opening part 2a may be sufficient.

The perspective view which showed the external appearance of the laser printer which concerns on one Embodiment of this invention. Perspective view of laser printer with paper cassette pulled out Cross section of the main part of the laser printer The partial side view which showed the part in which the upper peripheral part of the opening part was formed among the apparatus main bodies, and the paper feed cassette Partial perspective view showing a portion of the apparatus main body in which the upper peripheral edge portion of the opening is formed and a paper feed cassette (part 1) Partial perspective view showing the portion of the apparatus body where the upper peripheral edge of the opening is formed and the paper feed cassette (Part 2) A perspective view showing a pair of inner wall plates Top view of the paper cassette

Explanation of symbols

1. Laser printer (image forming device)
DESCRIPTION OF SYMBOLS 1a ... Apparatus main body 2a ... Opening part 3 ... Paper (recording medium)
4a ... cassette housing part 5 ... image forming part (image forming means)
8 ... Paper dust removing roller (conveying means)
9 ... Paper feed cassette
10: Separation roller (feeding means)
11 ... Separation pad (feeding means)
12: Paper feed roller (feeding means)
13: Opposing roller (conveying means)
14: Registration roller (conveying means)
70 ... Sponge (elastic member)
71, 72, 73 ... Peripheral portion 73a ... Opposing surface (first surface) of upper peripheral portion
74a ... Opposite surface (second surface) of pressing wall
84 ... locking piece (elastic locking piece)
85 ... engaged portion 86 ... positioning protrusion 87 ... positioning recess

Claims (10)

A cassette for storing a recording medium;
An image forming apparatus comprising: an apparatus main body having an opening that is open to the outside and having a cassette housing portion that accommodates the cassette so that the cassette can be pulled out through the opening.
The apparatus main body is formed with a first surface having an angle with respect to a drawing direction of the cassette at a peripheral portion of the opening,
The cassette is a cover wall in which, in a state of being accommodated in the cassette accommodating portion, overlaps at least the first surface of the peripheral portion of the opening, and a second surface is formed at a portion facing the first surface. Have
At least one of the first surface and the second surface is provided with an elastic member that is sandwiched between the first surface and the second surface in a state where the cassette is accommodated in the cassette housing portion. An image forming apparatus. The image forming apparatus according to claim 1, wherein the first surface and the second surface are surfaces orthogonal to a drawing direction of the cassette. The opening is formed in a portion recessed with a step with respect to the outer surface of the apparatus body, and the first surface is formed in a peripheral portion of the opening in the recessed portion,
The image forming apparatus according to claim 1, wherein the elastic member is arranged on the first surface without protruding to the cassette side. The image forming apparatus according to claim 1, wherein the elastic member is arranged on the second surface without protruding to the opening side. The said 1st surface is formed in the part connected to the clearance gap between the said apparatus main body and the said cassette among the peripheral parts of the said opening part, The Claim 1 characterized by the above-mentioned. Image forming apparatus. The image forming apparatus according to claim 5, wherein the first surface, the second surface, and the elastic member have a width that is at least equal to a width of a recording medium that can be stored in the cassette. The said cassette accommodating part is provided with the holding means which hold | maintains the said cassette against the reaction force of the said elastic member pressed in the state which accommodated the said cassette. The image forming apparatus according to claim 6. The holding means includes an elastic locking piece projecting from the cassette housing portion,
The image forming apparatus according to claim 7, further comprising a locked portion that is provided on the cassette side and engages with the elastic locking piece in a state where the cassette is accommodated. Either one of the cassette housing portion and the cassette is provided with a positioning projection for determining the position of the cassette relative to the cassette housing portion, and the other is provided with a positioning recess for engaging with the positioning projection,
The positioning protrusion and the positioning recess are positioned so that the cassette is in contact with the holding means and the elastic member is in a state of receiving a pressing force by the first surface and the second surface. 9. The image forming apparatus according to claim 7, wherein the image forming apparatus is characterized. A feeding unit that is disposed in a position close to the opening in the apparatus main body, and feeds the recording media stored in the cassette one by one while separating them;
Conveying means for conveying the recording medium fed by the feeding means to the side opposite to the opening;
The image forming apparatus according to claim 1, further comprising: an image forming unit that forms an image on the recording medium transported by the transport unit.

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