CASSETTE AND PRINTING APPARATUS

A cassette comprises a housing portion configured to have a placement face on which sheets are placed and to house sheets; and a standing wall configured to constitute a portion of the housing portion, and to regulate sheets on a back end side in a conveyance direction of sheets to be conveyed from the placement face to a printing apparatus, wherein the standing wall includes a protrusion that protrudes toward the placement face at a position above a predetermined position, which is at a height of sheets that can be stacked on the placement face.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a cassette to be used in a printing apparatus such as a printer.

Description of the Related Art

An image forming apparatus such as a printer is provided with a sheet feed cassette for stacking unprinted sheets.

For example, in a technique disclosed in Japanese Patent No. 6642051, a cassette cover that can be attached and detached is arranged on side walls of a sheet feed cassette, the cassette cover can pivot upward, and the sheet feed cassette includes a gripping portion having a sufficient rigidness.

However, in a sheet feed cassette disclosed in Japanese Patent No. 6642051, the sheet feed cassette protrudes from an image forming apparatus body, in an attaching and detaching direction thereof, depending on the sheet size, and therefore a design issue arises. In order to minimize the size of the sheet feed cassette in the attaching and detaching direction, it is desirable that a face of the sheet feed cassette opposite to a face that is inserted into an apparatus body (an opposite face in the insertion direction) is configured by one standing wall. However, when the opposite face is configured by one standing wall, it is difficult to secure a gripping portion of the sheet feed cassette, and secure the rigidness of the gripping portion when gripped.

SUMMARY OF THE INVENTION

The present invention has been made in view of the problems described above, and provides a technique for improving the operability by securing the rigidness of a cassette.

According to a first aspect of the present invention, there is provided a cassette comprising: a housing portion configured to have a placement face on which sheets are placed and to house sheets; and a standing wall configured to constitute a portion of the housing portion, and to regulate sheets on a back end side in a conveyance direction of sheets to be conveyed from the placement face to a printing apparatus, wherein the standing wall includes a protrusion that protrudes toward the placement face at a position above a predetermined position, which is at a height of sheets that can be stacked on the placement face.

According to a second aspect of the present invention, there is provided a printing apparatus to which the cassette described above.

DESCRIPTION OF THE EMBODIMENTS

Note that, although a case where the sheets on which printing is performed are paper will be described in the following embodiments, the sheets may also be made of a material other than paper, and need only be sheet type printing media on which printing can be performed.

First Embodiment

FIG.1is an exterior perspective view of an image forming apparatus (printing apparatus)1according to a first embodiment of the present invention.

InFIG.1, the image forming apparatus1has a document print function, a document scan function, and the like, and sheets are housed on a placement face of a sheet housing portion, which is inside of a sheet feed cassette6. A console panel2is arranged on a front face side of the apparatus, and a user can operate the image forming apparatus1in front of the console panel2.

The sheet feed cassette6can be attached to the image forming apparatus1, and is inserted in a depth direction through an opening portion8for inserting the sheet feed cassette that is formed in the image forming apparatus1, which will be described later. Here, the directions are defined. The insertion and removal direction of the sheet feed cassette of the image forming apparatus1matches a front-and-back direction of the apparatus, and the direction oriented toward back is defined as a back side in the insertion direction, as shown by an arrow3, and the opposite direction thereof is defined as a near side in the insertion direction. Also, left and right of the image forming apparatus1are defined as shown by an arrow4. Also, upward and downward of the image forming apparatus are defined as shown by an arrow5.

The configuration of this diagram will be described in more detail. A cassette cover7is attached above the sheet feed cassette6and prevents sheets from being exposed. When printing is executed, the console panel2is opened automatically or manually, and a print operation is executed.

FIG.2is a cross-sectional view schematically illustrating the inside of the image forming apparatus1, and shows a state in which main devices for performing printing are arranged. The print function will be described using this diagram.

Sheets100that are stacked and housed inside the sheet feed cassette are fed out one by one by a sheet feed roller101in response to an instruction to start printing, and are conveyed to a printing portion103through a guide portion102. In the printing portion103, a printing head104discharges ink while horizontally and reciprocally moving inside the image forming apparatus1, and as a result, an image is printed on a sheet that is conveyed by a conveyance roller106. The sheet on which an image is printed is discharged to a sheet discharge tray105. The sheet discharge tray105is arranged behind the console panel2inFIG.1, and the sheet discharge tray105is automatically or manually drawn out forward at the time of printing.

FIG.3is a perspective view of the sheet feed cassette in a state in which the cassette cover is attached. The cassette cover7can be attached to the sheet feed cassette (cassette main body)6in a direction shown by an arrow10. A later-described gripping portion (standing wall upper portion)11is provided in the sheet feed cassette6on the near side in the insertion direction thereof, and later-described rails12, and the like, for attaching the sheet feed cassette6to the image forming apparatus1are arranged on left and right side faces. Note that the console panel2is located on a placement face41side relative to a standing wall28, when the sheet feed cassette6is attached to the image forming apparatus1(refer to later-describedFIGS.5A and5B). Therefore, the gripping portion11and at least a portion of the cassette cover7are exposed outside the image forming apparatus1.

FIGS.4A to4Fare perspective views of the cassette cover.FIG.4Ais a perspective view of the entire upper face, andFIG.4Bis a perspective view of the entire lower face. Also,FIGS.4C to4Fare respectively enlarged views in the vicinities of left and right claws on the back side in the insertion direction and on the near side in the insertion direction. A branch number1of reference numerals indicates the left side, and a branch number2of reference numerals indicates the right side.

In the present embodiment, back side claw installation faces21respectively formed in back side projections20provided on the left and right sides are oriented in the same direction as the insertion direction of the sheet feed cassette6, and a back side claw22is provided on each of the faces. Also, near side claw installation faces24in near side projections23are oriented in a direction opposite to the insertion direction of the sheet feed cassette6, and a near side claw25is provided on each of the faces. Furthermore, positioning projections26for regulating the positional relationship between the sheet feed cassette6and the cassette cover7are respectively provided in the cassette cover7on the left and right sides. Also, a rib is formed in a horizontal direction in an end portion of the cassette cover7on the near side in the insertion direction, and contact parts43for contact with later-described hoods31(refer toFIG.5) are formed so as to be cut out of this rib. Note that a recess7ato be gripped by a user, along with the gripping portion11of the sheet feed cassette6, is formed at a position between the left and right contact parts43of the cassette cover7.

FIGS.5A and5Bare partial perspective views of the sheet feed cassette6on a near side in the insertion direction. There are cases where the sheet feed cassette6dominates the size of the image forming apparatus1, specifically, the size of the sheet feed cassette6in the insertion and removal direction. Therefore, in order to reduce the entire size of the image forming apparatus1, it is effective to reduce the size of the sheet feed cassette6in the insertion and removal direction. In order to minimize the size of the sheet feed cassette6in the insertion and removal direction, it is necessary to minimize the number of components of the sheet feed cassette6on the near side in the insertion direction, as far as possible.

The necessary component is the standing wall28on the near side in the insertion direction (back end side in a conveyance direction of sheets) for preventing stacked unprinted sheets from jutting out. The thickness of the standing wall28is about 1 to 5 mm. A configuration is appropriate in which an inner face29of the standing wall28regulates back ends of unprinted sheets in the conveyance direction, and an outer face30of the standing wall28forms a portion of the exterior of the image forming apparatus1. Furthermore, two hoods31(31-1,31-2) are provided on the inner face29of the standing wall28of the sheet feed cassette6. The height positions of lower faces of the hoods (protrusion)31are at a position that is higher than a predetermined position, which is an upper limit of stacking when unprinted sheets are stacked on the stacking face as a sheet bundle, and the positions of the hoods31in the transverse direction are positions separated from a center, which is in the vicinity of the gripping portion11of the sheet feed cassette6, by an approximately same distance toward left and right.

Holes40(40-1,40-2) are arranged in the placement face41on which sheets are placed, at positions opposing the hoods31. These holes40are used to remove a mold when injection molding of the sheet feed cassette6is performed. As a result of using such a manufacturing method, the standing wall28and hoods31can be integrally formed. Note that, even in a case of injection molding, a placement face41in which holes are not provided at positions corresponding to the holes40can be adopted, as shown inFIG.12. In the present embodiment, sheets can be placed under the hoods31. Note that the strength of the hoods can be increased by semicircularly and continuously projecting portions between the hoods and the placement face, for example.

In order to make sheets unlikely be caught when unprinted sheets are set, the shape of each hood31viewed from above is formed as a rounded-off shape. The upper face of the hood31is in parallel with the upper face of the standing wall28. Also, side wall upper faces32of the sheet feed cassette6on the left and right sides are provided with holes33into which the back side projections20of the cassette cover7enter. Similarly, holes34to which the near side projections23of the cassette cover7enter are provided in the sheet feed cassette6on the near side in the insertion direction. Furthermore, positioning holes35for receiving the positioning projections26of the cassette cover7are arranged in the left and right side wall upper faces32of the sheet feed cassette6, in order to determine the positional relationship with the cassette cover7.

FIG.6is an A-A cross-sectional view ofFIG.3. In a state in which the cassette cover7is fitted into a prescribed position, an end portion27of the cassette cover7on the near side in the insertion direction is arranged at a position adjacent to the inner face29of the standing wall28of the sheet feed cassette6on the near side in the insertion direction. Therefore, the contact parts43of the cassette cover7for contact with the hoods31are positioned immediately above the hoods31. Here, the cassette cover7and the hoods31need not be brought into contact, and a gap may be present therebetween.

FIGS.7A to7Care B-B cross-sectional views ofFIG.3.FIG.7Ais a general drawing of the cross-sectional view, andFIGS.7B and7Care respectively enlarged views in the vicinity of the claws on the back side in the insertion direction and on the near side in the insertion direction.

In the state in which the cassette cover7is fitted into the prescribed position, the back side claws (claw portions)22of the cassette cover7are fixed (engaged with) to the sheet feed cassette6by engagement faces37, as shown inFIG.7B. Here, an angle38of the engagement face37of the back side claw22is set to an angle α relative to the direction of removing the cassette cover7. The angle α is an angle larger than 90°, in the present embodiment.

On the other hand, the near side claws (claw portions)25of the cassette cover7are fixed (engaged with) to the sheet feed cassette6by engagement faces39, as shown inFIG.7C. Here, an angle40of the engagement face39of the near side claw25is set to an angle β relative to the direction of removing the cassette cover. The angle β is an angle less than or equal to 90°, in the present embodiment.

When unprinted sheets are set to the sheet feed cassette6, the cassette cover7needs to be removed, and when the cassette cover7is removed, the cassette cover7is lifted upward in a state shown inFIG.3, or a back side end portion36of the cassette cover7inFIG.6is lifted upward. Then, the cassette cover7pivots and opens in a direction of an arrow13inFIG.3, with portions in the vicinity of the hoods31and a near side end portion27of the cassette cover7thereabove being pivot axes.

This pivot motion is realized as a result of the back side claws22easily coming off by an upward force, because the angle α of the engagement faces37of the back side claws22is larger than the angle β of the engagement faces39of the near side claws25.

After the cassette cover7is opened, unprinted sheets are set to the sheet feed cassette6, and the cassette cover7is attached to the sheet feed cassette6from above. When the cassette cover7is attached, attachment can be performed from one of the back side claw22side and the near side claw25side, or attachment can be performed on the both sides at the same time. Then, the positioning projections26of the cassette cover7are inserted into the respective positioning holes35of the sheet feed cassette6, and as a result, the positional relationship between the sheet feed cassette6and the cassette cover7is correctly regulated. Note that, in the present embodiment, the positioning projections26are each located between the back side projection20and the near side projection23, but the position is not limited thereto.

When the sheet feed cassette6replenished with sheets is attached to the image forming apparatus1, a user grips the gripping portion11of the sheet feed cassette6, and inserts the sheet feed cassette6into the image forming apparatus1through the later-described opening portion8.

FIG.8is a C-C cross-sectional view ofFIG.3. When the user grips the gripping portion11of the sheet feed cassette6, his/her hand also grips the standing wall28of the sheet feed cassette6and the cassette cover7, and the cassette cover7deforms at this time. This is because there is no hood31, for suppressing deformation of the cassette cover7, immediately below the gripping portion11of the sheet feed cassette6, and a portion in the vicinity of the gripping portion11of the cassette cover7deforms downward, with contact points with the hoods31on the left and right sides being points of support. If there are no hoods31at all, the cassette cover7deforms more than necessary, and it will not feel rigid to the user. As a result of the presence of hoods31, the user can have rigidity feeling when gripping the gripping portion11of the sheet feed cassette6. Also, if the size of the gripping portion11is sufficiently large for being gripped, as a result of reducing the horizontal distance between the two hoods31, a gripping portion that only deforms a small amount and feels rigid to the user can be obtained. That is, as a result of appropriately setting the number of hoods and the arrangement thereof, the feeling of rigidity of the sheet feed cassette6and cassette cover7when the sheet feed cassette6is attached and detached can be appropriately controlled.

Furthermore, the positional relationship between the parts of the sheet feed cassette6and the cassette cover7in the present embodiment will be described. Regarding the height direction, as shownFIGS.7A to7C, the engagement faces37and39of the claws are at positions lower than the upper limit height of sheets that are stacked, and the lower faces of the hoods31are at positions higher than the upper limit height of sheets that are stacked, as described above. The heights of the side wall upper faces32of the sheet feed cassette6are at positions the same as or higher than the upper limit height of sheets that are stacked, and are positioned below the lower faces of the hoods31. Also, the contact parts43of the cassette cover7for contact with the hoods31are arranged immediately above the hoods31with a small gap therebetween. The upper end of the standing wall28of the sheet feed cassette6on the near side in the insertion direction is located at a position higher than the cassette cover7, with which a space of the gripping portion11for the user’s finger being caught is formed.

Regarding the insertion direction of the sheet feed cassette6, the hoods31that protrude from the inner face29of the standing wall28in the near side in the insertion direction protrude toward the back side in the insertion direction beyond the contact faces of the contact parts43of the cassette cover7. This is because, when the user strongly grips the cassette cover7and the sheet feed cassette6, the contact parts43of the cassette cover7are prevented from riding over the hoods31of the sheet feed cassette6and largely moving downward.

Also, in the present embodiment, the projections20and23each having a claw and the positioning projections26that are arranged in the cassette cover7are not arranged horizontally symmetrically. This is because, due to the structure of the image forming apparatus1, although unprinted sheets cannot be arranged at the center of the sheet feed cassette6in the horizontal direction, the gripping portion11of the sheet feed cassette6is arranged at the center of the sheet feed cassette6in the horizontal direction, from a design viewpoint.

When the user grips the gripping portion11, the cassette cover7deforms with the two hoods31being points of support, and the cassette cover7deforms downward at positions closer to the gripping portion11relative to the hoods31, in the horizontal direction, but the cassette cover7deforms so as to be lifted upward at positions farther from the gripping portion11relative to the hoods31. The force of deformation of being lifted upward is larger on the near side in the insertion direction of the sheet feed cassette6than on the back side, because of the closeness to the gripping portion11and the hoods31. In contrast, the engagement faces37and39of the claws resist the force of the cassette cover7lifting upward, and as a result, the cassette cover7is suppressed from coming off. In the present embodiment, the unbalance in force is resolved by arranging the projections23each having a claw on the near side in the insertion direction of the sheet feed cassette6substantially symmetrically in the horizontal direction.

Note that, in the present embodiment, the objective is achieved with the configuration described above, but the present invention is not limited to the configuration described above. For example, the side wall upper faces32may have heights so as to be positioned above the lower faces of the hoods31, and in this case as well, the cassette cover7moves with portions in the vicinity of the near side end portion27of the cassette cover7that are located above the hoods31serving as the pivot axes. In addition thereto, a horizontally symmetrical configuration may also be adopted.

FIG.9is a perspective view illustrating the manner of inserting the sheet feed cassette6to the image forming apparatus1.FIG.10is a cross-sectional view of the opening portion8for receiving the sheet feed cassette6and a portion in the vicinity of a claw engagement face of the cassette cover7, in a state in which the sheet feed cassette6is attached to the image forming apparatus1.

As a result of the user gripping the sheet feed cassette6and the cassette cover7and inserting them into the opening portion8of the image forming apparatus1, the rails12of the sheet feed cassette6align with rails (not shown) inside the image forming apparatus1, the position in the vertical and horizontal directions is determined, and the sheet feed cassette6is attached. At an insertion end, the entering position of the sheet feed cassette6is regulated by an unshown stopper, and the position of the sheet feed cassette6inside the image forming apparatus1in the insertion direction is determined.

Here, as shown inFIG.10, the back side claws22have entered inside the image forming apparatus1relative to the opening portion8. The back side claws22, which are easily coming off, are caused to enter inside the image forming apparatus1, and therefore, the back side claws22are suppressed from coming off. On the other hand, the near side claws25of the cassette cover7are originally structured so as not to easily come off from the sheet feed cassette6, and therefore, although they are exposed from the image forming apparatus1, no problem arises. According to such a structure, when the image forming apparatus1is packaged in a state of the sheet feed cassette6being attached thereto, falling out of the cassette cover7can be prevented without performing processing for suppressing falling out on the cassette cover7by a package material, a tape, or the like.

As described above, according to the present embodiment, the rigidness of the gripping portion of the sheet feed cassette including the cassette cover can be secured while keeping the size of the sheet feed cassette in the insertion and removal direction small. Also, an image forming apparatus can be provided in which the cassette cover is unlikely to come off due to impact at the time of packaging.

Second Embodiment

In the first embodiment, an example in which hoods are provided at two locations has been described. In a second embodiment, a hood is provided at one location will be described. The other configurations are the same as those of the first embodiment described above, and therefore the description thereof will be omitted.

The height position of the hood is similar to the first embodiment, but the position in the transverse direction is set to a position immediately below the gripping portion11(recess7a), for example. The length of the hood in the transverse direction may be the same as the range determined as the gripping portion, or may also extend over the entire width range.

According to such a configuration, the deformation of the cassette cover7when a user grips the gripping portion11of the sheet feed cassette6can be suppressed, and the rigidness can be secured.

Third Embodiment

In the first embodiment, an example has been described in which the orientation of the installation faces21of the back side claws22of the cassette cover7is the same as the insertion direction of the sheet feed cassette6. In the third embodiment, an example will be described in which the installation faces of back side claws22of the cassette cover7face the inside of the sheet feed cassette. The other configurations are the same as those of the first embodiment described above, and therefore the description thereof will be omitted.

In the present embodiment, as shown inFIGS.11A and11B, installation faces51of back side claws of back side projections50provided in the cassette cover7face an inward direction of the sheet feed cassette6, and the back side claws52are provided on the installation faces51.

In accordance therewith, side wall portions of the sheet feed cassette6are provided with holes into which the respective back side projections50enter, and engagement faces (not shown) that engage with the back side claws52. Note that the angle relationship between the engagement faces on the back side and the near side is similar to that of the first embodiment described inFIGS.7A to7C.

In such a configuration as well, as a result of lifting the cassette cover7upward, the portions in the vicinity of the near side end portion27and the hoods31function as pivot axes for the cassette cover7, and as a result, the cassette cover7can be easily removed.

Note that, in the embodiments described above, an ink-jet type multifunction peripheral has been illustrated as the image forming apparatus, but the present invention is not limited thereto, and the image forming apparatus may also be a facsimile or another image forming apparatus such as a laser beam printer. The similar effects can be obtained when the present invention is applied to the sheet feed cassettes used is these image forming apparatuses.