Patent Application
20160257507
1. Field of the Invention
The present invention relates to a sheet feeding apparatus applicable to an image forming apparatus such as a printer and to an image forming apparatus including the same.
2. Description of the Related Art
Hitherto, there is known a sheet feeding apparatus comprising a first storage portion in which a sheet is stacked, a feed roller feeding the sheet from the first storage portion, a second storage portion arrayed horizontally with the first storage portion, and a sheet bundle shifting plate shifting sheets within the second storage portion collectively to the first storage portion as disclosed in Japanese Patent No. 3411135 for example. The sheet feeding apparatus also includes a shift home sensor. A state of the shift home sensor is determined when a sheet feed cassette is set after turning the power ON. The shift home sensor is turned ON when a back fence (sheet shift portion) is located at a home position and is turned OFF when the back fence is not located at the home position. Then, in a case when the sheet feed cassette is drawn out of an apparatus body while shifting the sheets during which the sensor is turned OFF, the back fence is moved when the sheet feed cassette is set again to continue the operation of shifting the sheet bundle from the second storage portion to the first storage portion.
However, in a case when the sheet feed cassette is erroneously drawn out of the apparatus body while shifting the sheets, there is a possibility of causing the following problem in resetting the sheet feed cassette by noticing that the sheet is left in the first storage portion in the sheet feeding apparatus described above. That is, it is conceivable to erroneously end up setting a sheet bundle to a back side of the back fence (on the second storage portion side of the back fence) stopping on the first storage portion side in setting the sheet bundle to the sheet feed cassette drawn out of the apparatus body. In this case, the back fence cannot return to its home position on the second storage portion side because the sheet bundle stacked on the back of the back fence obstructs. Thereby, such problems that the apparatus body stops to operate and an alarm is indicated occur, and recovery is not made until when an user removes the sheet bundle erroneously stacked as described above, thus inviting a cumbersome resetting work.
According to an embodiment of the invention, a sheet feeding apparatus comprises an apparatus body, a feed member feeding a sheet, a sheet storage member configured to be movable to an attachment position where the sheet storage member is attached to the apparatus body and to a draw-out position where the sheet storage member is drawn out of the attachment position, and comprising a first sheet storage portion in which the sheet to be fed by the feed member is stored and a second sheet storage portion being provided adjacent horizontally to the first sheet storage portion and storing a sheet, a sheet shifting portion configured to shift the sheet in the second sheet storage portion to the first sheet storage portion, the sheet shifting portion being capable of positioning at a first position and a second position farther than the first position from the first sheet storage portion, a driving unit moving the sheet shifting portion by linking with the sheet shifting portion in a state in which the sheet storage member is located at the attachment position, and a moving portion configured to move the sheet shifting portion from the first position to the second position in a state in which the link of the sheet shifting portion with the driving unit is disconnected in response to a drawing operation of the sheet storage member from the apparatus body in a state in which the sheet shifting portion has moved to the first position by the driving unit.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
An embodiment of the present invention will be described in detail below with reference to the drawings. At first, an image forming apparatus comprising a sheet feeding apparatus of the embodiment of the present invention will be described with reference to
As illustrated in
The apparatus body 201a is provided with a discharge space S for discharging a sheet below the image reading apparatus 202. Toner cartridges 215 are disposed under the discharge space S, and a plurality (three in the present embodiment) of sheet feeding apparatuses 51, 52, and 53 is disposed at a lower part of the apparatus body 201a. The apparatus body 201a is provided with attachment spaces, not illustrated, into/out of which sheet feed cassettes 91 and 92 described later in sheet feeding apparatuses 51 and 52 can be attached/drawn. The apparatus body 201a is also provided with an attachment space 15 (see
The image forming portion 201b is what adopts a four drum full-color system and includes a laser scanner 210 and four process cartridges 211 of forming four color toner images of yellow (Y), magenta (M), cyan (C), and black (K).
Here, each process cartridge 211 includes a photosensitive drum 212, i.e., a photosensitive body, a charger 213, a developer 214, and a cleaner not illustrated. The image forming portion 201b also includes an intermediate transfer unit 201c above the process cartridge 211.
The intermediate transfer unit 201c includes an intermediate transfer belt 216 wrapped around a driving roller 216a and a tension roller 216b. The intermediate transfer unit 201c also includes primary transfer rollers 219 disposed inside of the intermediate transfer belt 216 and being in contact with an inner surface of the intermediate transfer belt 216 at positions facing the photosensitive drums 212. The intermediate transfer belt 216 is composed of a film-like member, is in contact with the respective photosensitive drums 212 and is rotated in a direction of an arrow in
The respective color toner images having negative polarity on the photosensitive drums 212 are sequentially superimposed and transferred onto the intermediate transfer belt 216 by positive transfer bias applied from the primary transfer rollers 219 to the intermediate transfer belt 216. Thereby, a color image is formed on the intermediate transfer belt 216. Disposed at a position facing the driving roller 216a is a secondary transfer roller 217 transferring the color image formed on the intermediate transfer belt 216 onto a sheet P. It is noted that a secondary transfer portion is constructed by a secondary transfer nip portion N formed by the driving roller 216a and the secondary transfer roller 217 being in pressure contact with the driving roller 216a.
A fixing portion 220 is disposed downstream in a sheet conveyance direction of the secondary transfer roller 217, and a first discharge roller pair 225a, a second discharge roller pair 225b, and a double-side inverting portion 201d are disposed above the fixing portion 220. The double-side inverting portion 201d includes an inverse roller pair 222 configured to rotate normally and reversely, a re-conveyance passage R conveying a sheet of which an image has been formed on a first surface thereof again to the image forming portion 201b, and others. It is noted that an image forming unit 27 forming the image on the sheet P delivered from the sheet feeding apparatuses 51, 52, and 53 is constructed by the image forming portion 201b, the secondary transfer nip portion N, and the fixing portion 220.
The image forming apparatus constructed as described above operates as follows. Image information read by the image reading apparatus 202 or inputted from an outside device such as a personal computer (PC) not illustrated is converted into electrical signals after undergoing image processing and is transmitted to a laser scanner 210 of the image forming portion 201b.
Then, in the image forming portion 201b, surfaces of the photosensitive drums 212 of the respective process cartridges 211 are scanned by laser beams corresponding to image information of yellow, magenta, cyan, and black component colors emitted from the laser scanner 210. Thereby, the surfaces of the photosensitive drums 212 charged homogeneously with a predetermined polarity and potential by the charger 213 are sequentially exposed, and electrostatic latent images of yellow, magenta, cyan, and black are sequentially formed on the photosensitive drums 212 of the respective process cartridges 211.
Then, the electrostatic latent images are developed and visualized by toners of the respective colors of yellow, magenta, cyan, and black, and the respective color toner images on the respective photosensitive drums 212 are sequentially superimposed and transferred onto the intermediate transfer belt 216 by the primary transfer bias applied to the primary transfer rollers 219. Thereby, a color toner image is formed on the intermediate transfer belt 216.
Meanwhile, the sheet P delivered from either one of the sheet feeding apparatuses 51, 52, and 53 passes through a registration roller pair 240 and is sent to the secondary transfer nip portion N. Here, the registration roller pair 240 corrects a skew of the sheet P by making a front end of the sheet P follow a nip portion of the registration roller pair 240 such that the sheet P abutting against the nip portion forms a loop. The toner images formed in the image forming portion 201b are secondarily and collectively transferred onto the sheet P at the secondary transfer nip portion N.
In succession, the sheet P onto which the toner images have been secondarily transferred as described above is conveyed to the fixing portion 220 to be heated and pressed to fix the toner images on the sheet P as a color image. After that, the sheet P on which the color image has been fixed is discharged to the discharge space S by the first discharge roller pair 225a and is stacked on a stacking portion 26 provided within the discharge space S.
The sheet feeding apparatuses 51 and 52 are provided respectively with sheet feed cassettes 91 and 92 storing the sheet P. The sheet feeding apparatus 51 is also provided with a sheet feed portion 24 delivering the sheet P stored in the sheet feed cassette 91 toward a sheet drawing roller pair 14. The sheet feeding apparatus 52 is provided with the sheet feed portion 24 delivering the sheet P stored in the sheet feed cassette 92 toward a drawing roller pair 25.
The sheet feed portion 24 corresponding to the sheet feed cassette 91 includes a pickup roller 11, a feed roller 12, and a retard roller 13 disposed above and downstream in a sheet feed direction of the sheet feed cassette 91. The sheet feed portion 24 corresponding to the sheet feed cassette 92 includes a pickup roller 21, a feed roller 22, and a retard roller 23 disposed above and downstream in the sheet feed direction of the sheet feed cassette 92.
The sheet feeding apparatus 53 is provided with a sheet feed cassette 93 storing the sheet P and a sheet feed portion 24 delivering the sheet P stored in a sheet feed cassette 93 toward a pull-out roller pair 34 located downstream of the sheet feed portion 24. The sheet feed portion 24 corresponding to the sheet feed cassette 93 includes a pickup roller 31, a feed roller 32, and a retard roller 33 disposed above and downstream in the sheet feed direction of the sheet feed cassette 93.
The pickup rollers 11 and 21 are turnably supported by arms not illustrated respectively turnable centering on the feed rollers 12 and 22 and deliver the sheet P by rotating while being in pressure contact with the sheet P stored respectively in the sheet feed cassettes 91 and 92. The sheet feed cassettes 91 and 92 are supported such that they can be attached to/drawn out of the apparatus body 201a in a front-back direction of
The pickup roller 31 is turnably supported by an arm not illustrated turnable centering on the feed roller 32 and delivers the sheet P stored in the sheet feed cassette 93 by rotating while being in pressure contact with the sheet P stored in the sheet feed cassette 93. It is noted that the sheet feed cassette 93 is supported such that the sheet feed cassette 93 can be attached to/drawn out of the apparatus body 201a along drawing rails 61 and 62 in the front-back direction of
Then, in response to a start of an image forming operation, the sheet P is separated and fed one by one from either one of the sheet feed cassettes 91, 92, and 93 by the sheet feed portion 24. The sheet P sent out by either one of the pickup rollers 11, 21, and 31 is conveyed by either corresponding one of the feed rollers 12, 22, and 32. If the sheets are doubly fed at this time, the sheet P of the second one and thereafter are returned to a side of the sheet feed cassettes 91, 92, and 93 by either corresponding one of the retard rollers 13, 23, and 33. The sheet P separated and conveyed by either corresponding one of the feed rollers 12, 22, and 32 and the retard rollers 13, 23, and 33 is sent downstream farther by either one of the pull-out roller pairs 14, 25, and 34 and is conveyed to the registration roller pair 240.
Next, the sheet feeding apparatus 53 of the present embodiment will be described in detail below with reference to
As illustrated in
The sheet feeding apparatus 53 is provided with a lifter plate 35 supported so as to lift the stacked sheet P within the first sheet storage portion 28b. The pickup roller 31, disposed above the lifter plate 35, of the apparatus body 201a (see
As illustrated in
The sheet feed cassette 93 includes the first sheet storage portion 28b on the right side of the drawings and the second sheet storage portion 28a on the left side of the drawings, and is supported so as to be attachable to/drawable out of an attachment space 15 (see
The sheet feeding apparatus 53 also comprises a fixed set tray 88 formed such a part thereof extends from a bottom of the second sheet storage portion 28a to a side of the first sheet storage portion 28b. The sheet bundle moving member 37 supported so as to slidably move from the second sheet storage portion 28a to the first sheet storage portion 28b side along the set tray 88 is disposed in the sheet feed cassette 93. The sheet bundle moving member 37 is provided so as to be able to be in contact with the sheet bundle Sb set in the second sheet storage portion 28a. That is, the sheet bundle moving member is supported so as to be able to slidably move in the horizontal direction in
As illustrated in
The arm member 36 is constructed so as to be able to move between a partitioning position and an opening position by being driven by a partitioning solenoid 20 (see
A home position of the arm member 36 is normally the partitioning position where the arm member 36 projects as a partition between the sheet bundles Sb of the first and second sheet storage portions 28b and 28a. Then, the arm member 36 recedes from the partitioning position to the opening position in shifting the sheet bundle Sb stacked in the second sheet storage portion 28a on the left side to the first sheet storage portion 28b on the right side in
Still further, as illustrated in
Next, the sheet feeding apparatus 53 of the present embodiment will be described in detail with reference to
As illustrated in
Then, as illustrated in
According to the present embodiment, the tensile spring 44 and the charge member 43 compose the forced moving mechanism, i.e., moving portion, 19 forcibly moving the sheet bundle moving member (sheet shifting portion) 37 from the first sheet storage portion 28b side to the second sheet storage portion 28a side. Here, in describing a relationship between two positions of the sheet bundle moving member 37, a position close to the first sheet storage portion 28b will be expressed as ‘the first sheet storage portion 28b side’ and a position far from the first sheet storage portion 28b will be expressed as ‘the second sheet storage portion 28a side’. It is noted that the pair of tensile springs 44 may be one tensile spring 44 or three or more tensile springs 44 may be used depending on their disposition.
Disposed under the sheet bundle moving member 37 are driving shafts 46a and 40a extending in the width direction orthogonal to the sheet feed direction and rotatably supported upstream and downstream in the sheet feed direction (in the direction of the arrow A in
A bent portion 37a formed at a lower part of the sheet bundle moving member 37 is fixed such that the sheet bundle moving member 37 erects by fixing members 45 on a lower side of an inner circumferential surface of the timing belt 41. The bent portion 37a is configured so as to project in the width direction from the set tray 88 as illustrated in
Next, the driving mechanism and others moving the sheet bundle moving member 37 of the present embodiment will be described with reference to
As illustrated
The sheet feed cassette 93 is provided also with side restricting plates 38 and 39 restricting and aligning the sheet P within the sheet feed cassette 93 in the width direction (in a direction of an arrow B in
In response to a drive of the timing belt 41 driven by the driving pulley 40 as illustrated in
The charge member 43 is supported so as to slidably move within a guide portion 42 illustrated in
As illustrated in
A driving gear 76 is secured to a rotating shaft 77 rotatably supporting the drive transmitting coupling 49 to the apparatus body 201a, and a transmission gear 75 rotatably supported by the apparatus body 201a is engaged with the driving gear 76. A driving shaft 40a supported in this state is supported in a condition in which the driving shaft 40a penetrates through a penetration portion 39a formed through the side restricting plate 39. It is noted that a driving mechanism 29 is composed of the driving motor 50, the pinion 74, the transmission gear 75, and the driving gear 76.
The rotation of the driving motor 50 is transmitted to the driven coupling 48 through the pinion 74, the transmission gear 75, the driving gear 76, the rotating shaft 77, and the drive transmitting coupling 49. Still further, because this rotation is also transmitted to the driving pulley 40 through the driving shaft 40a, the sheet bundle moving member 37 is moved in the direction of the arrow A illustrated in
Still further, according to the present embodiment, the driving mechanism 29 also includes the timing belt 41 rotated by the output of the driving motor 50 transmitted from the drive transmitting coupling 49 to the driven coupling 48. Then, the sheet bundle moving member 37 is linked with the timing belt 41 so as to move between the first and second sheet storage portions 28b and 28a during when the timing belt 41 rotates. This arrangement makes it possibly to steadily move the sheet bundle moving member 37 by transmitting the driving force of the driving motor 50 to the timing belt 41 through the driving shaft 40a and the driving pulley 40.
As illustrated in
Because the sheet bundle moving member 37 returns to a position as indicated in
In the present embodiment, the home position of the sheet bundle moving member 37 is the leftmost position as indicated in
However, if the sheet feed cassette 93 is drawn out of the apparatus body 201a, the transmission route of the driving force of the driving motor 50 is disconnected, so that the sheet bundle moving member 37 cannot return to the home position by the driving force of the driving motor 50. According to the present embodiment, however, the sheet bundle moving member 37 can be moved instantly in the left direction by the operation of the charge member 43 and the tensile spring 44.
Here, ‘instantly’ means a time, e.g., within one second, less than a time required for the user to draw the sheet feed cassette 93 out of the apparatus body 201a. Because the sheet bundle moving member 37 moves instantly in the left direction as described above, there is no space for setting the sheet bundle Sb on the left set tray 88, and the user will not erroneously set the sheet bundle Sb at this position. Because this arrangement makes is possible to avoid the user from erroneously setting the sheet bundle Sb, it is possible to avoid a stoppage of the printer 201 or the occurrence of a cumbersome resetting work.
Next, a control system involved in the shift of the sheet bundle of the present embodiment will be described with reference to
As illustrated in
The opening/closing sensor 16 is composed of a photo interrupter and detects a state of the sheet feed cassette 93 attached to the apparatus body 201a in response to a light blocking plate 17 (see
The bundle pressing HP sensor 81 (see
The partitioning sensor 83 has substantially the same structure with the opening/closing sensor 16 described above. The partitioning sensor 83 detects whether the arm member 36 is located at the partitioning position or the opening position based on the relationship of the advancing/receding move of the a light blocking plate fixed on the arm member 36 side with a photo interrupter fixed on the sheet feed cassette 93 side.
The lifter HP sensor 84 (see
The driving motor 50 rotationally drives to move the sheet bundle moving member 37 from the second sheet storage portion 28a side to the first sheet storage portion 28b side and to return the sheet bundle moving member 37 from the first sheet storage portion 28b side to the second sheet storage portion 28a side in accordance to the controls made by the control portion 67.
The partitioning solenoid 20 advances/sets back a plunger not illustrated so as to turn the arm member 36 to the partitioning position/opening position in accordance to the controls made by the control portion 67. The driving motor 50 rotates in accordance to the controls of the control portion 67, and the rotation thereof is transmitted to the drive transmitting coupling 49 through the gear train including the pinion 74. The lifter motor 86 operates so as to lift the lifter plate 35 such that the uppermost sheet P on the lifter plate 35 is always and stably in contact with the pickup roller corresponding to a level of the pickup roller 31 in accordance to the controls of the control portion 67.
Corresponding to the detection signals from the various sensors described above, the control portion 67 controls and drives the partitioning solenoid 20, the driving motor 50, and the lifter motor 86. The control portion 67 also controls a display on of an user's operating screen not illustrated.
Here, a series of states in which the sheet bundle Sb within the second sheet storage portion 28a is shifted to the first sheet storage portion 28b when the sheet P within the first sheet storage portion 28b runs out will be described with reference to
That is,
Thus, it is possible to continue an image forming process even if the sheet P within the first sheet storage portion 28b runs out by repeatedly replenishing the sheet bundle Sb by automatically and continuously performing the steps in
As illustrated in
It is noted that the driving unit 10 is composed of the driving mechanism 29 comprising the driving motor 50 as a driving source outputting the driving force, the drive transmitting coupling 49, the driven coupling 48, and the timing belt 41 as the endless belt. The driving unit 10 is linked with the sheet shifting portion through a transmission portion 18 described later to transmit the driving force of the driving unit 10 to the sheet shifting portion and to drive the sheet shifting portion. The present embodiment is configured to be able to move the sheet bundle moving member 37 in an inverse direction toward the second sheet storage portion 28a by the forced moving mechanism (the moving portion) 19 when the transmission of the driving force of the driving unit 10 is disconnected.
This arrangement makes it possible to move the sheet bundle moving member 37 automatically to the home position side when the sheet feed cassette 93 is drawn out at the moment when the shift of the sheet bundle by the move of the sheet bundle moving member 37 is finished (when the sheet feed cassette 93 is drawn out at the moment of finishing to shift the sheet bundle). Thus, it is possible to move the sheet bundle moving member 37 automatically to the home position side of the second sheet storage portion 28a.
That is, if the sheet feed cassette 93 is drawn out of the attachment space 15 and the link with the driving unit 10 is disconnected in the state in which the sheet bundle moving member 37 has moved to the first sheet storage portion 28b side, the forced moving mechanism 19 forcibly moves the sheet bundle moving member 37 to the second sheet storage portion 28a side. That is, in the case when the sheet feed cassette 93 is drawn out during when the sheet bundle is being shifted, the sheet bundle moving member 37 can be moved to the second sheet storage portion 28a side instantly by the action of the forced moving mechanism 19. Due to that, even if the sheet feed cassette 93 is erroneously drawn out during the shift of the sheet bundle Sb, it is possible to avoid such problem that the sheet bundle Sb is erroneously stacked from occurring because the sheet bundle moving member 37 can be forcibly moved to the second sheet storage portion 28a side.
That is, no such problem that the user erroneously sets the sheet bundle Sb on the left side of the sheet bundle moving member 37 (the second sheet storage portion 28a side) occurs in a state in which the sheet bundle moving member 37 cannot return to the second sheet storage portion 28a side. Due to that, it is possible to avoid the user from erroneously setting the sheet bundle Sb to the sheet feed cassette 93 drawn out of the apparatus body 201a on the back side of the sheet bundle moving member 37 stopping after having moved to the first sheet storage portion 28b side. Accordingly, it is possible to reliably avoid such situations that the sheet bundle moving member 37 cannot return to the home position and the printer 201 has to be stopped or an alarm is indicated from otherwise occurring by erroneously setting the sheet bundle Sb. Thus, it is possible to steadily prevent such problem requiring the cumbersome work that the printer 201 is not recovered until when the user removes the sheet bundle Sb from occurring.
Still further, according to the present embodiment, the charge member 43, i.e., a pulling member, is linked with the tensile spring 44 so as to pull the tensile spring 44 to the first sheet storage portion 28b side through the sheet bundle moving member 37 moving from the second sheet storage portion 28a side to the first sheet storage portion 28b side. When the load of the driving motor (driving source) 50 to the forced moving mechanism 19 is cut, the sheet bundle moving member 37 receives the forced moving force of the tensile spring 44 through the charge member 43 and is moved to the second sheet storage portion 28a side. This arrangement makes it possible to move the sheet bundle moving member 37 reliably to the second sheet storage portion 28a when the load to the forced moving mechanism 19 is cut.
Still further, the driving unit 10 can move the sheet bundle moving member 37 from the first sheet storage portion 28b to the second sheet storage portion 28a side in the state in which the sheet feed cassette 93 is attached to the attachment space 15. Because the sheet feeding apparatus 53 includes the driving unit 10 as described above, it is possible to move the sheet bundle moving member 37 steadily and smoothly between the first and second sheet storage portions 28b and 28a by such simple mechanical configuration.
Still further, according to the present embodiment, the transmission portion 18 is composed of the drive transmitting coupling 49 supported on the apparatus body 201a side, the driven coupling 48 supported on the sheet feed cassette 93 side, and the timing belt 41. The sheet bundle moving member 37 is firmly linked with the timing belt 41 so as to be able to move between the first and second sheet storage portions 28b and 28a by the rotation of the timing belt 41. The driven coupling 48 can be engaged and coupled with the drive transmitting coupling 49 by attaching the sheet feed cassette 93 to the attachment space 15. Still further, the driven coupling 48 can be decoupled and disconnected from the drive transmitting coupling 49 by drawing the sheet feed cassette 93 out of the attachment space 15.
It is possible to simply and reliably switch the link state and the disconnect state by linking/decoupling the driven coupling 48 on the sheet feed cassette 93 side with/from the drive transmitting coupling 49 on the apparatus body 201a side. Still further, in response to the link of the driven coupling 48 with the drive transmitting coupling 49, the driving force of the driving motor 50 is transmitted from the drive transmitting coupling 49 to the driven coupling 48, and the timing belt 41 is rotated. It is possible to steadily transmit the driving force of the driving motor 50 to the sheet bundle moving member 37 by the simple mechanical configuration as described above.
The forced moving mechanism 19 includes the tensile spring, i.e., a spring member, 44 charging the moving force by being dragged by the sheet bundle moving member 37 moving from the second sheet storage portion 28a to the first sheet storage portion 28b. When the sheet feed cassette 93 is drawn out of the attachment space 15, the sheet bundle moving member 37 is moved to the second sheet storage portion 28a side by the tensile spring 44 in the state in which the load of the transmission portion 18 is cut. At this time, it is possible to steadily make the moving force act on the sheet bundle moving member 37 and move the sheet bundle moving member 37 to the second sheet storage portion 28a side just by drawing the sheet feed cassette 93 out of the apparatus body 201a.
The charge member 43 also pulls the tensile spring 44 to the first sheet storage portion 28b side by engaging with the sheet bundle moving member 37 moving from the second sheet storage portion 28a side to the first sheet storage portion 28b side. Then, when the load of the driving motor 50 on the forced moving mechanism 19 is cut, the sheet bundle moving member 37 receives the moving force of the tensile spring 44 through the charge member 43 and is returned to the second sheet storage portion 28a side. Therefore, it is possible to release the load of the driving motor 50 being applied on the forced moving mechanism 19 and to move the sheet bundle moving member 37 to the second sheet storage portion 28a side quickly by the moving force of the tensile spring 44 automatically by drawing the sheet feed cassette 93 out of the apparatus body 201a.
The forced moving mechanism 19 also charges the moving force forcibly moving the sheet bundle moving member 37 to the second sheet storage portion 28a side when the sheet bundle moving member 37 is moved from the second sheet storage portion 28a side to the first sheet storage portion 28b side by the driving unit 10. This arrangement makes it possible to reliably charge the moving force in the direction of returning the sheet bundle moving member 37 after extending the tensile spring 44 just by moving the sheet bundle moving member 37 to the first sheet storage portion 28b side by the driving force of the driving motor 50.
It is noted that while the known tensile spring whose load increases as the spring is dragged more has been exemplified in the present embodiment, another method using a compression type spring in contrary may be adopted as long as the sheet bundle moving member 37 can be moved to the home position side. That is, the spring is not limited to the tensile spring 44 of the present embodiment.
Still further, while the charge member 43 slidably moving within the guide portion 42 illustrated in
It is noted that while the sheet bundle moving member 37 has been configured to instantly move in the left direction by the action of the charge member 43 and the tensile spring 44 when the user draws the sheet feed cassette 93 out of the apparatus body 201a in the present embodiment, the present invention is not limited to such configuration. For instance, the sheet bundle moving member 37 may be moved by the charge member 43 and the tensile spring 44 also at timing when the user draws the sheet feed cassette 93 out to the draw-out position. The user will notice that the sheet bundle moving member 37 is not located at the home position by watching that the sheet bundle moving member 37 is moving to the home position side. Then, it is also possible to urge the user to move the sheet bundle moving member 37 to the home position. In this case, the sheet bundle moving member 37 may not be returned to the home position by the action of the charge member 43 and the tensile spring 44.
Still further, the case when the sheet feed cassette is drawn out of the apparatus body 201a when the sheet bundle moving member 37 is located between the first and second sheet storage portions 28b and 28a has been described with reference to
Next, a first modified example of the embodiment described above will be described with reference to
While a basic part of the first modified example is the same with the configuration of the embodiment described above with reference to
The arrangement described above also makes it possible to move the sheet bundle moving member 37 from the second sheet storage portion 28a side to the first sheet storage portion 28b side by the timing belt 41 rotated by the rotating driving pulley 40 by the first modified example in the same manner with the embodiment described above. At this time, it is possible to charge the moving force by rotating the spiral spring member 70 through the transmission gear 71.
According to the forced moving mechanism 19 of the first modified example constructed as described above, it is possible to charge the moving force by rotating the spiral spring member 70 in linkage with the move of the sheet bundle moving member 37 from the second sheet storage portion 28a side to the first sheet storage portion 28b side. Then, it is possible to move the sheet bundle moving member 37 to the second sheet storage portion 28a side by the spiral spring member 70 in the state in which the load of the transmission portion 18 is cut when the sheet feed cassette 93 is drawn out of the attachment space 15.
According to the first modified example described above, the driven coupling 48 on the sheet feed cassette 93 side is decoupled from the drive transmitting coupling 49 on the apparatus body 201a side and the driving force of the driving motor 50 is released when the sheet feed cassette 93 is drawn out of the apparatus body 201a. Thereby, the spiral spring member 70 thus set free rotates in an inverse direction, so that the driving pulley 40 is driven in a direction of an arrow B, a lower part of the timing belt 41 rotates in a direction of an arrow C, and the sheet bundle moving member 37 is moved in a direction of an arrow D. This arrangement makes it possible to obtain the same effect with the embodiment described above because the sheet bundle moving member 37 instantly moves toward the home position on the second sheet storage portion 28a side.
It is noted that in the first modified example, it is possible to apply a pre-load by the spiral spring member 70 to the sheet bundle moving member 37 at the home position indicated by a solid line in
In contrary, it is conceivable that the sheet bundle moving member 37 returns only to an intermediate position indicated by a two-dot chain line in
Next, a second modified example of the embodiment described above will be described with reference to
While a basic part of the second modified example is the same with the configuration of the embodiment described above with reference to
The arrangement described above also makes it possible to move the sheet bundle moving member 37 from the second sheet storage portion 28a side to the first sheet storage portion 28b side by the timing belt 41 rotated by the rotating driving pulley 40 by the second modified example in the same manner with the embodiment described above. At this time, it is possible to charge the moving force by lifting the weight 79 while winding the wire 80 around the driving shaft 40a.
According to the forced moving mechanism 19 of the second modified example constructed as described above, it is possible to charge the moving force as a potential energy by the weight 79 lifting in linkage with the move of the sheet bundle moving member 37 from the second sheet storage portion 28a side to the first sheet storage portion 28b side. Then, it is possible to move the sheet bundle moving member 37 to the second sheet storage portion 28a side by the moving force of the weight 79 immediately falling in the state in which the load of the transmission portion 18 is reduced when the sheet feed cassette 93 is drawn out of the attachment space 15.
According to the second modified example described above, the driven coupling 48 on the sheet feed cassette 93 side is decoupled from the drive transmitting coupling 49 on the apparatus body 201a side and the driving force of the driving motor 50 is released when the sheet feed cassette 93 is drawn out of the apparatus body 201a. Thereby, because the weight 79 thus set free falls by its own weight, the driving pulley 40 is rotated in the direction of the arrow B, the lower part of the timing belt 41 rotates in the direction of the arrow C, and the sheet bundle moving member 37 is moved in the direction of the arrow D. This arrangement makes it possible to obtain the same effect with the embodiment described above because the sheet bundle moving member 37 instantly moves toward the home position on the second sheet storage portion 28a side.
It is noted that the configuration in which the sheet bundle moving member 37 is forcibly moved to the second sheet storage portion 28a side in response to the decoupling of the driven coupling 48 from the drive transmitting coupling 49 has been described in the embodiment and in the first and second modified examples. However, the present invention is not limited to such configuration and may be configured as follows. For instance, it is possible to configure such that the driving unit such as the motor and the gear train not illustrated driving the charge member 43 is provided on the sheet feed cassette 93 side and power is supplied to the motor from the apparatus body 201a side through a connector or the like not illustrated. Then, it is possible to configure such that the sheet bundle moving member 37 moves toward the second sheet storage portion 28a when the supply (transmission) of the power through the connector is disconnected. It is noted that in this case, it is preferable to use a normal DC motor not generating cogging torque and others as the motor setting on the sheet feed cassette 93 side. Such arrangement also makes it possible to bring about effects substantially the same with those of the embodiment and the first and second modified examples described above.
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. 2015-043472, filed Mar. 5, 2015 and Japanese Patent Application No. 2015-241946, filed Dec. 11, 2015 which are hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-043472 | Mar 2015 | JP | national |
| 2015-241946 | Dec 2015 | JP | national |
