Hereinafter, an exemplary embodiment for carrying out the present invention will be described in detail referring to the drawings.
Here, this image forming portion 102 includes a photosensitive drum 107 forming a toner image, a transfer roller 106 transferring the toner image having been formed on the photosensitive drum 107 to the sheet S, a charging device 109 uniformly charging the surface of the photosensitive drum, and a developing device 110. Incidentally, a process cartridge 111 includes the photosensitive drum 107, the developing device 110, and the charging roller 109.
In addition, the sheet feeding apparatus 103 includes a universal cassette 1, being a sheet containing unit in which a large number of sheets S can be contained, and a feed roller 103A made of a high frictional material, being a sheet feeding portion disposed above the universal cassette 1 and configured to feed a sheet S contained in the universal cassette 1.
Moreover, the universal cassette 1 includes a cassette body 1A in which the sheet S is contained, and an intermediate plate 6 on which the sheet S is stacked, as well as which is held pivotally in a vertical direction with a shaft 50a being a fulcrum at the cassette body 1A and biased toward the feed roller 103A by a coil spring 51. Further, by pressing up this intermediate plate 6 toward the feed roller 103A by the coil spring 51, the sheets S that are stacked on the intermediate plate 6 are to be pressed to the feed roller 103A.
Furthermore, there is provided a separation pad 101, being a separation unit configured to separate the sheets having been fed out by the feed roller 103A one by one.
Now, an image forming operation of the laser beam printer 100 constructed in such a way will be described.
First, based on an image signal from a host computer (not illustrated), a laser beam is irradiated onto the photosensitive drum 107 which surface has uniformly been preliminarily charged by the charging roller 109, and which is rotated in a clockwise direction from a laser scanner 122 that is provided at the apparatus main body 2. Whereby, an electrostatic latent image is formed on the surface of the photosensitive drum 107. Next, the electrostatic latent image on the surface of the photosensitive drum 107 is developed with a toner on the developing roller 110, and a toner image is formed on the photosensitive drum 107.
On the other hand, the feed roller 103A starts to rotate in a predetermined timing, and in cooperation therewith, the intermediate plate 6 that is biased onto the feed roller side by the force of the coil spring 51 is rotated upward. As a result, a leading edge portion of the sheets S that are stacked on the intermediate plate 6 is brought into pressure contact with the feed roller 103A by a predetermined force. Here, the feed roller 103A is controlled so as to rotate in a counterclockwise direction only at the time of feeding a sheet, and feeds the pressure-contact sheet S by a frictional force. Incidentally, when plural sheets S on the intermediate plate 6 are fed out at the same time, only the uppermost sheet S is separated from the others by the action of the separation pad 101 to be conveyed to the downstream.
Next, the uppermost sheet S having being separated by the separation pad 101 in such a way is fed to a registration unit 105, and a skew feed thereof is corrected. Thereafter, the sheet S is conveyed by the registration unit 105 to a transfer portion 108 that is formed of the photosensitive drum 107 and a transfer roller 106. At the transfer portion 108, the toner image having been formed on the photosensitive drum 107 as already described is electrically attracted by the transfer roller 106 to be transferred to the sheet S.
Incidentally, the sheet S onto which the toner image has been transferred with the arrangement is thereafter conveyed to a fixing unit 115 that is formed of a heating unit 113 and a pressure roller 114 by a conveying belt 104. Due to that this sheet S is heated and pressed at this fixing unit 115, the toner image will be fixed. Further, thereafter, the sheet S is discharged onto a sheet discharge tray 121 on the top of the apparatus main body by a pair of intermediate discharge rollers 118 and a pair of discharge rollers 119.
Then, when various sizes of sheets are contained in the cassette body, the side edge regulating members 3a and 3b are brought into contact with the side edge of the sheet to regulate the side edge position of the sheet, as well as the trailing edge regulating member 5 is brought into contact with the trailing edge of the sheet to regulate the trailing edge position of the sheet. Whereby, the sheet can be contained in a positioned state.
Incidentally, when a sheet is fed, the universal cassette 1 is mounted in the apparatus main body 2 from a direction indicated by an arrow A. The intermediate plate 6 is pressed upward about a support shaft 7 by the spring 51. Whereby, the sheet that is positioned by the side edge regulating members 3a and 3b and the trailing edge regulating member 5 is pressed to the feed roller 103A. Incidentally, the sheets having been pressed to the feed roller 103A are fed out one by one by a feeding action of the feed roller 103A to be fed to the image forming portion 102.
In the meantime, a pair of the side edge regulating members 3a and 3b is provided with rack portions 31a and 31b extended in the same direction (direction indicated by an arrow B) as the width direction, being a moving direction of the side edge regulating members 3a and 3b at bottom portions respectively. Furthermore, these rack portions 31a and 31b are guided by a guide groove (not illustrated) provided in the direction indicated by the arrow B at a bottom plate of the cassette body 1A to be movable in the width direction.
Incidentally, a pinion 4 is provided rotatably at a central portion on the bottom face of the caste body 1A. With this pinion 4, rack teeth that are formed at the rack portions 31a and 31b are meshed and engaged respectively. With the arrangement, when either of the side edge regulating members is made to move in the width direction, by the action of the pinion 4 and the rack portions 31a and 31b, the other side edge regulating member is cooperated to move in the direction opposite to one side edge regulating member.
Then, by causing both of the side edge regulating members 3a and 3b to move in the width direction at the same time by the movement of one side edge regulating member in such a way to bring them into contact with the side edge of sheets stacked on the intermediated plate 6, the sheets can be easily positioned in the width direction.
The trailing edge regulating member 5 is guided by a guide groove (not illustrated) provided in a direction indicated by an arrow C in the bottom plate of the cassette body 1A to be movable in a feeding direction. In addition, as illustrated in
Furthermore, there is provided an operating portion 8 that operates the trailing edge regulating member 5, and that releases the engagement of the holding member 9 with the cassette body 1A by the below-described interlock so that the trailing edge regulating member 5 is movable. Then, in the case where this operating portion 8 is operated to release the engagement of the holding member 9 with the cassette body 1A, the trailing edge regulating member 5 comes to be movable, thus enabling to change a set position. Furthermore, after the trailing edge regulating member 5 has been operated to move, the holding member 9 will be engaged with the cassette body 1A again, thereby enabling to hold the position.
Moreover, at the trailing edge regulating member 5, as illustrated in
Further, when the trailing edge regulating member 5 is moved to a position of regulating a trailing edge position of a standard-size sheet, this click pin 11 is elastically engaged with a click groove 11a formed in positions corresponding to standard-size positions of sheets in the cassette body 1A, a click feeling is generated. Owing to such construction, since the click feeling is generated when the trailing edge regulating member 5 is set in the standard-size positions of sheets, the operability when a user operates the trailing edge regulating member 5 is improved.
The holding member 9, as illustrated in
Here, as in this embodiment, due to that the teeth of the tooth row 9a and the rack tooth row 1a are triangular teeth, a high holding strength can be ensured mechanically. As a result, since the pitch of the tooth row 9a and the rack tooth row 1a can be made smaller, fine adjustments of a set position of the trailing edge regulating member 5 can be conducted.
Moreover, in this embodiment, as illustrated in
With the arrangement, in the case where the trailing edge regulating member 5 is applied with the force in the larger size regulation direction, due to that respective substantially perpendicular faces of the tooth row 9a and the rack tooth row 1a are brought into contact with each other, this force can be received. Whereby, a high holding force of the trailing edge regulating member 5 can be ensured.
In addition, the holding member 9 is pivotably provided in a direction indicated by an arrow E about a pivot shaft 9b at a slide portion 5B (refer to
In addition, the holing member 9 is biased to the rack tooth row 1a side by an elastic member 10 for biasing the click pin 11, whereby the holding member 9 is held in a state in which the tooth row 9a is engaged with the rack tooth row 1a. As a result, the trailing edge regulating member 5 is engaged with the cassette body 1A to be held.
The operating portion 8, as illustrated in
For example, to contain a sheet of a large size, when the operating portion 8 is pressed in the same direction indicated by an arrow F as the moving direction of the trailing edge regulating member 5 so as to move the tailing edge regulating member 5 in the larger size regulation direction indicated by an arrow F in
Whereby, the holding member 9 is pivoted in a direction indicated by an arrow H, being a direction of the engagement with the cassette body 1A being released about the pivot shaft 9b, and thus the tooth row 9a will be disengaged from the rack tooth row 1a. Due to that the engagement between the tooth row 9a and the rack tooth row 1a is released in such a way, thereafter, when the trailing edge regulating member 5 is moved in the larger size regulation direction to change a set position, the tailing edge regulating member 5 can be easily moved.
Incidentally, after having been moved, when the operating portion 8 is released from being pressed, the operating portion 8 is returned to the original state in which the tooth row 9a and the rack tooth row la are engaged with each other, and thus the trailing edge regulating member 5 can be held in a set position.
In addition, to contain a sheet of a small size, when the operating portion 8 is pressed in the same direction indicated by an arrow G as the moving direction of the trailing edge regulating member 5 so as to move the trailing edge regulating member 5 in the smaller size regulation direction indicted by an arrow G in
Whereby, the holding member 9 is pivoted in a direction indicated by an arrow H about the pivot shaft 9b, and the engagement between the tooth row 9a and the rack tooth row 1a is released, thus enabling to move the trailing edge regulating member 5 in the smaller size regulation direction to change a set position. Incidentally, after having been moved, when the operating portion 8 is released from being pressed, by the action of the elastic member 10, the operating portion 8 is returned to the original state in which the tooth row 9a and the rack tooth row 1a are engage with each other, and thus the trailing edge regulating member 5 can be held in the set position.
With the arrangement, by the interlock 5C according to this embodiment, in both directions (directions indicated by the arrows F and G) in which the operating portion 8 is press-operated, the holding member 9 is pivoted in the direction indicted by the arrow H, and the engagement between the tooth row 9a and the rack tooth row 1a is released, so that the trailing edge regulating member 5 can be moved.
That is, in this embodiment, when the operating portion 8 is operated to move the trailing edge regulating member 5, only by press-operating the operating portion 8 in the same direction as the direction intended to move the trailing edge regulating member 5, the engagement of the holding member 9 can be released. Whereby, by pressing the trailing edge regulating member 5 in the same direction as the pivoted direction of the operating portion 8 while the operating portion 8 is being pivoted, the trailing edge regulating member 5 can be moved by a series of operation, thus to improve the movement operability of the tailing edge regulating member 5. That is, only by pressing the operating portion 8 in a direction intended to move the trailing edge regulating member 5, the trailing edge regulating member 5 can be moved.
Note that, although in this embodiment, the shaft 8b forming the interlock 5C is provided at the operating portion 8 and the groove 9c is provided at the holding member 9, the shaft 8b may be provided at the holding member 9 and the groove 9c may be provided at the holding member 9. Furthermore, although in this embodiment, an example in which the present invention is applied to the trailing edge regulating member 5 is shown, the same construction can be applied to the side edge regulating members 3a and 3b. Whereby, even in the side edge regulating members 3a and 3b, such an effect that a movement operability can be improved, can be obtained.
Now, a second exemplary embodiment according to the present invention will be described.
In this embodiment, as described above, a pair of the side edge regulating members 3a and 3b is constructed such that rack teeth formed at rack portions 31a and 31b are in meshing engagement with a pinion 4 respectively, and thus when one side edge regulating member is moved in the width direction, the other side edge regulating member is moved in the direction opposite to the one side edge regulating member in association with the movement of the other side edge regulating member. Furthermore, one side edge regulating member 3a of a pair of the side edge regulating members 3a and 3b to be guided by a guide groove (not illustrated) that is formed in a direction indicated by the arrow B at a bottom plate of a cassette body is provided with a holding member 13 that is engaged with the cassette body 1A with the below-described engaging portion to hold a predetermined position. In addition, this one side edge regulating member 3a, as illustrated in
Furthermore, by operating the operating portion 12 to disengage the holding member 13 from the cassette body 1A, one side edge regulating member 3a can be moved to change a set position. Furthermore, after having been moved, the holding member 13 is engaged with the cassette body 1A again, whereby the set position of a pair of the side edge regulating members 3a and 3b can be held.
According to this embodiment, at the bottom face of the holding member 13, as illustrated in
Therefore, by the tooth row 13a being engaged with the corresponding rack tooth row 1b as well as biased to the rack tooth row side by the elastic member 14, one side edge regulating member 3a will be engaged with a cassette body 1A, and a pair of the side edge regulating members 3a and 3b is held in a set position corresponding to a sheet size. These teeth row 13a of the holding member 13 and rack tooth row 1b of the cassette body 1A form a holding mechanism.
Here, as this embodiment, due to that the teeth of the tooth row 13a and the rack tooth row 1b are triangular, a high holding strength can be ensured mechanically. As a result, since the pitch of the tooth row 13a and the rack tooth row 1b can be made smaller, fine adjustments of the set position of the side edge regulating members 3a and 3b can be conducted.
Furthermore, in this embodiment, as illustrated in
With the arrangement, in the case where the side edge regulating members 3a and 3b are applied with the force in the larger size regulation direction, respective substantially perpendicular faces of the tooth row 13a and the rack tooth row 1b are brought into pressure contact with each other, whereby this force can be received. As a result, a large holding power of the side edge regulating members 3a and 3b can be ensured.
In this embodiment, the operating portion 12 includes two shafts 12a and 12b. When the operating portion 12 is pressed, depending on a pressing direction, the operating portion 12 is to be pivoted in a direction indicated by an arrow L with respect to the side edge regulating member main body 3A with one of these two shafts 12a and 12b as a fulcrum.
Furthermore, in this embodiment, when the operating portion 12 is pressed, the operating portion 12 is pivoted with one of the support shafts 12a and 12b as a fulcrum, as well as the other support shaft 12a, 12b is to press upward a pressing portion 13c, 13d that is provided at the upper portion of the holding member 13. Whereby, the holding member 13 is moved slidingly upward, the teeth of the tooth row 13a and the rack tooth row 1b are spaced apart to release the engagement between the holding member 13 and the cassette body 1A, and thus one side edge regulating member 3a can be moved.
In this embodiment, the two support shafts 12a and 12b of the operating portion 12 and the pressing portions 13c and 13d that are provided at the upper portion of the holding member 13 form an interlock 5C configured to release the engagement between the holding member 13 of one side edge regulating member 3a and the cassette body 1A in association with the operation of the operating portion 12.
Now, with reference to
For example, to contain a sheet of a large size, when the operating portion 12 is pressed in the same direction indicated by an arrow N as a moving direction of the operating portion 12 so as to move one side edge regulating member 3a in the larger size regulation direction indicated by the arrow N in
Whereby, the engagement between the tooth row 13a provided at the holding member 13 and the rack tooth row 1b provided at the cassette body 1A is released, and one side edge regulating member 3a can be moved. Thus, one side edge regulating member 3a can be moved in the larger size regulation direction to change a set position. Accompanied by this movement, the other side edge regulating member 3b is moved in the direction opposite to the moving direction of one side edge regulating member 3a. Incidentally, after having been moved, when the operating portion 12 is released from being pressed, by the action of the elastic member 14, the operating portion 12 is returned to the original state in which the tooth row 13a and the rack tooth row 1b are engaged with each other, and thus the side edge regulating members 3a and 3b can be held (secured) in a set position.
Likewise, to contain a sheet of a small size, when the operating portion 12 is pressed in the same direction indicated by an arrow R as the moving direction of the operating portion 12 so as to move one side edge regulating member 3a in the smaller size regulation direction indicated by the arrow R of
Whereby, the engagement between the tooth row 13a provided at the holding member 13 and the rack tooth row 1b provided at the cassette body 1A is released, and one side edge regulating member 3a can be moved. Thus, one side edge regulating member 3a can be moved in the smaller size regulation direction to change a set position. Accompanied by this movement, the other side edge regulating member 3b is moved in the direction opposite to the moving direction of one side edge regulating member 3a. Incidentally, after having been moved, when the operating portion 12 is released form being pressed, by the action of the elastic member 14, the operating portion 12 is returned (in the direction indicated by the arrow P) to the original state in which the tooth row 13a and the rack tooth row 1b are engaged with each other, and thus the side edge regulating members 3a and 3b can be held (secured) in a set position.
With the arrangement, with the interlock 5C according to this embodiment, in both directions (directions indicated by the arrows N and R), being directions of one side edge regulating member 3a capable of moving in which the operating portion 12 is press-operated, the holding member 13 is moved in the direction indicted by the arrow P, and the engagement between the tooth row 13a and the rack tooth row 1b is released, so that one side edge regulating member 3a can be moved.
That is, in the case of moving the side edge regulating members 3a and 3b, only by pressing the operating portion 12 to be pivoted, the engagement between one side edge regulating member 3a and the cassette body 1A can be released.
Accordingly, only by pressing the operating portion 12 in the same direction as the moving direction of one side edge regulating member 3a, one side edge regulating member 3a can be released from being held and moved at the same time, the movement operability of the side edge regulating members 3a and 3b can be improved.
Incidentally, although in this embodiment, an example in which the present invention is applied to the side edge regulating members 3a and 3b is described, the same construction can be applied to the trailing edge regulating member 5. Whereby, such the same effect that the operability of the trailing edge regulating member 5 can be improved, can be obtained.
In each of the above-mentioned embodiments, although by a meshing engagement between a tooth row of a holding member, being an engaging portion and a rack tooth row of a cassette body, being an engaged portion, regulating members are engaged, the engaging portion and the engaged portion are not limited to the construction of the meshing engagement of teeth. For example, making an engaging portion in a convex shape, and making an engaged portion in a concave shape, by the engagement of the convex portion with the concave portion, the regulating members can be held in a predetermined position.
In this embodiment, although an example in which the present invention is applied to a trailing edge regulating member or a side edge regulating member that is provided at a universal cassette is described, the present invention is not limited to this example. The present invention may be applied to a side edge regulating member to be provided at a manual tray of an image forming apparatus or an original tray for stacking an original of an original conveying apparatus.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2006-267953 filed Sep. 29, 2006, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2006-267953 | Sep 2006 | JP | national |