Patent Application
20160244284
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2015-035162 filed on Feb. 25, 2015, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a sheet feeder for supplying a sheet(s) of paper to an image forming section of an image forming apparatus, and the image forming apparatus using the sheet feeder, and more particularly to a sheet feeder having a sheet stacking tray provided to be opened and closed with respect to a main body and being mainly suitable for manual sheet feeding, and an image forming apparatus using the sheet feeder.
2. Description of Related Art
Conventionally, an image forming apparatus is provided with a manual sheet feeder formed of an outer panel a part of which will be opened to allow manual loading of a sheet(s) therein in addition to a sheet cassette for supplying a sheet(s) therefrom. One example of such sheet feeders is disclosed in Japanese patent application publication No. 2005-298112. The sheet feeder in this publication is provided with guide members placed in contact with side edges of a stack of sheets to regulate the stacked sheets. Each guide member includes a posture maintaining means at one end to maintain the posture of the guide member. Each guide member further includes a pressing means at the other end to press the side edges of the stacked sheets. These guide members are used to prevent skewing (oblique shift) of a sheet to be conveyed.
However, the conventional sheet feeder mentioned above has the following disadvantages. In response to recent demands for downsizing of apparatus, it is becoming difficult to prevent the occurrence of sheet skewing. In association with downsizing of the image forming apparatus, a sheet tray such as a manual sheet feeding tray to be used by opening and closing a part of the apparatus also has been reduced in size of a lifting plate and other surrounding parts or components. Accordingly, sheet guides additionally provided in the lifting plate also have been reduced in size. This is a disadvantageous condition to prevent sheet skewing. Size reduction of the sheet guides will cause difficulty in adjusting the sheet guides to fit close to the sheet width. This is because such small sheet guides are unnoticeable and also difficult to grasp.
The present invention has been made to solve the foregoing problems of the conventional techniques. Specifically, the present invention has objects of providing a sheet feeder capable of properly conveying a sheet loaded on a tray with even an apparatus configuration adapted for downsizing, and providing an image forming apparatus using the sheet feeder.
To achieve at least one of the abovementioned objects, one aspect of the present invention provides a sheet feeder comprising: a sheet stacking tray provided to stack a sheet to be supplied to a main body, the sheet stacking tray being configured to be opened and closed with respect to the main body by rotation about a rotation axis defined in a direction perpendicular to a sheet feeding direction; a first width regulating member provided in the sheet stacking tray and configured to regulate a side edge of the sheet in a sheet width direction and to have a variable regulating width; an auxiliary tray provided at a position in the main body where the auxiliary tray does not move in association with an opening/closing operation of the sheet stacking tray, the auxiliary tray being configured to stack the sheet in cooperation with the sheet stacking tray; a second width regulating member provided in the auxiliary tray and configured to regulate the side edge of the sheet in the sheet width direction and to have a variable regulating width; a link member interlocking the first width regulating member and the second width regulating member in a regulating width changing operation; and a sheet feeding member provided in the main body and configured to feed one by one the sheets stacked over the sheet stacking tray and the auxiliary tray.
In the sheet feeder in the above aspect, sheet feeding from the sheet stacking tray is performed while the sheet stacking tray is in an open position. A sheet(s) to be fed from the sheet stacking tray is stacked over the sheet stacking tray and the auxiliary tray. The side edge of the sheet(s) in the sheet width direction is regulated by the first width regulating member on the sheet stacking tray and by the second width regulating member on the auxiliary tray. Since the first width regulating member and the second width regulating member are interlocked with each other through the link member, these regulating members regulate the sheet(s) with the same regulating width. Under such a regulation in the sheet width direction by the first width regulating member and the second width regulating member, sheets stacked on the sheet stacking tray and the auxiliary tray are fed one by one by the sheet feeding member.
In the sheet feeder configured as above, regulating the sheet(s) in the width direction is performed on both the sheet stacking tray and the auxiliary tray. Thus, the first width regulating member and the second width regulating member, even though they are individually small in size, can provide as a whole a great regulating effect in the width direction and also can be visible to a user. Since the sheet(s) is subjected to width-direction regulation even on the auxiliary tray located near the sheet feeding member, the occurrence of sheet skewing can be satisfactorily prevented.
Another aspect of the present invention provides an image forming apparatus provided with an image forming section and a sheet feeder for supplying a sheet to the image forming section, wherein the sheet feeder is configured in the above aspect.
A detailed description of preferred embodiments of the present invention will now be given referring to the accompanying drawings. In the present embodiment, the invention is applied to an image forming apparatus 1 shown in
The image forming apparatus 1 is further provided with a fixing section 26, ejecting rollers 27, and an output tray 28. Accordingly, a sheet formed with an image is stacked onto the output tray 28. The image forming apparatus 1 is further provided with an exposer 29, a toner supplying section 30, a belt cleaner 31, and others, which are auxiliary devices for image formation in addition to the foregoing sections or components.
Besides the above components, the image forming apparatus is further provided with a manual feeding tray (a sheet stacking tray) 40. This manual feeding tray 40 can be opened and closed. In a closed state, the manual feeding tray 40 forms a part of an outer panel of the image forming apparatus 1. In an open state shown with a solid line in
On the sheet stacking surface 43 of the manual feeding tray 40, sheet width regulating members (first width regulating members) 44 are placed one on each of the front F side and the rear B side. The sheet width regulating members 44 are used to regulate both side edges, in the width direction W, of a sheet(s) stacked on the sheet stacking surface 43. The sheet width regulating members 44 are slidable symmetrically on the F side and the B side in the width direction W on the sheet stacking surface 43. Accordingly, various sheet sizes can be treated. Such sheet width regulating members 44 are located on the manual feeding tray 40 on a side close to the main body 20.
In
The auxiliary tray 45 is also provided with sheet width regulating members (second width regulating members) 46. In
The sheet width regulating members 44, the sheet width regulating members 46, and the link members 47 will be further explained referring to
As is clear from
The space area in each sheet width regulating member 46 opens at least on a side toward the corresponding sheet width regulating member 44 and on an opposite side to the auxiliary tray 45 (an upper side in
Each link member 47 is formed, on the other end, with a rounded portion 50 having a convex shape protruding downward, i.e., toward the sheet stacking surface 43. Further, in the sheet width regulating member 44 in which the rounded portion 50 of the link member 47 is inserted, the internal space area opens toward the sheet width regulating member 46 and the lower side, i.e., toward the sheet stacking surface 43. Accordingly, the rounded portion 50 is placed in contact with the sheet stacking surface 43 within the sheet width regulating member 44.
Consequently, the sheet width regulating members 44, the sheet width regulating members 46, and the link members 47 provide as a whole a sheet width change adapting function and also react to the opening and closing operations of the manual feeding tray 40. Specifically, the operation of the manual feeding tray 40 from the open state to the closed state is counterclockwise tilting or flapping motion indicated by an arrow A in
Sliding of the rounded portion 50 absorbs variations in distance between the sheet width regulating member 44 and the sheet width regulating member 46 caused by the opening/closing operation of the manual feeding tray 40. In this manner, the paired sheet width regulating members 44 and 46 are integrally moved in the width direction W and can adjust to the opening/closing operation of the manual feeding tray 40.
The sheet width regulating members 44, the sheet width regulating members 46, and the link members 47 are, as mentioned above, integrally moved in the width direction W to fit various sizes of the sheets in the width direction. For this end, the manual feeding tray 40 and the auxiliary tray 45 are respectively formed with a guide groove 53 and a guide groove 54 to guide movement of the sheet width regulating members 44 and the sheet width regulating member 46 in the width direction W.
Herein, the rounded portion 50 of the above-mentioned link member 47 is designed such that a smallest curvature radius R of the convex shape is larger than the width P of the guide groove 53. Preferably, the curvature radius R is more than 1.1 times as large as the width P. This is because, as long as the curvature radius R is larger than the width P, even when the rounded portion 50 moves across the guide groove 53, the rounded portion 50 does not largely fall into the guide groove 53. This allows the rounded portion 50 to smoothly slide on the sheet stacking surface 43. In some apparatus structures, the guide groove 53 may be located within a slidable range of the rounded portion 50. In this case, it is necessary to take account of a relationship between the curvature radius R and the width P. For another apparatus structure in which the guide groove 53 is located out of the slidable range of the rounded portion 50, the above relationship does not need to be taken account. Each sheet width regulating member 44 may be formed with a bottom closing the cavity or space area in which the rounded portion 50 is placed, instead of allowing the cavity area opening toward the sheet stacking surface 43. In this case, the foregoing relationship between the curvature radius R and the width P also does not need to be considered.
Herein, as an alternative, the link member 47 may be configured, opposite to the above, such that one end is attached to be rotatable about a boss with respect to the sheet width regulating member 44 and the other end is slidable on the auxiliary tray 45 side. The relationship between the curvature radius R and the width P in such a case can be considered in relation to the width of the guide groove 54 if necessary.
It is alternatively conceivable that the link member 47 is configured such that both the sheet width regulating member 44 and the sheet width regulating member 46 are attached to be rotatable about respective bosses and held against sliding with respect to the manual feeding tray 40 or the auxiliary tray 45. In this case, however, the distance between both ends of the link member 47 has to be variable. It is accordingly conceivable that the link member is made up of two pieces as shown in
The manual feeding tray 40 internally contains, under the sheet stacking surface 43, a mechanism for moving the pair of sheet width regulating members 44 on the F side and the B side in a symmetric way with respect to the center in the width direction W. This mechanism will be explained below referring to a bottom view in
As shown in
Similarly, an elongated member 57 is attached to the bottom surface of the sheet width regulating member 44 on the B side, even though it is beyond the range of
At least one of the elongated member 55 and the elongated member 57 (the elongated member 55 in
This configuration can therefore prevent easy movement of the sheet width regulating members 44 even when each sheet width regulating member 44 receives a force in the width direction W generated by for example turbulence or unstable motion of a sheet(s) at the time of start of sheet feeding. Further, the sliding resistance member 63 placed in the manual feeding tray 40 can also prevent undesired movement of the sheet width regulating members 44 due to machine vibrations transmitted thereto from the main body 20 side.
One of the elongated member 55 and the elongated member 57 (the elongated member 57 in
Upon detection of this electrical resistance Z, the main body 20 of the image forming apparatus 1 can grasp the positions of the sheet width regulating members 44, i.e., the size in the width direction W of a sheet(s) currently stacked on the manual feeding tray 40. Specifically, the volume resistor 65 is configured to output a signal representing the regulating width of the sheet width regulating members 44. Since the volume resistor 65 is mounted in the manual feeding tray 40, the positions of the sheet width regulating members 44 can be detected without being greatly influenced by noise due to mechanical vibrations of the main body 20. The main body 20 that receives the foregoing signal from the volume resistor 65 can control automatic magnification adjustment and other adjustments for image formation.
The aforementioned elongated member 57 may be provided with only the rack teeth member 59 without including the rack teeth member 64. In this case, the gear teeth 86 of the volume resistor 65 may be arranged to mesh with the rack teeth member 59 or with the pinion gear 60. As an alternative, the volume resistor 65 and the pinion gear 60 are provided coaxially and instead the gear teeth 86 may be fixed. The elongated member 55 or the elongated member 57 may be provided with a resistance wire instead of using the volume resistor 65, and the manual feeding tray 40 may be provided with a fixed contact to obtain changes in resistance value. Further, instead of the electrical resistance, electrical capacity or electrical physical quantity that changes depending on the positions of the sheet width regulating members 44 may be used. As another alternative, a signal representing the positions of the sheet width regulating members 44 may be acquired through some optical means. An elastic member that can expand and contract according to the positions of the sheet width regulating members 44 may be provided to acquire the relevant signal from its distortion.
The elongated member 61 is also provided to a back surface of the sheet width regulating member 46 on the auxiliary tray 45 as shown in
Instead of providing the sliding resistance member 63, the foregoing volume resistor 65 may be configured as a resistor with a gear teeth 86 that generates a certain degree of mechanical resistance to movement.
The sheet width regulating surface 52 of each sheet width regulating member 46 is provided with a soft member 66 projecting to a sheet side. The position of the soft member 66 in the sheet width regulating surface 52 is near a leading edge (a left end in
The sheet stacking surface 43 of the manual feeding tray 40 is attached with a scale label 69. Specifically, the scale label 69 is attached in an area to be overlapped by the outer surface 67, that is, in a position close to the shoulder portion 68 of the sheet width regulating member 44 on the F side on the sheet stacking surface 43. When the sheet width regulating members 44 are moved in the width direction W to fit to the sheet width, the shoulder portion 68 moves over the scale label 69. This scale label 69 is ruled with a dividing line 70 parallel to the width direction W. The dividing line 70 indicates a pathway along with the shoulder portion 68 will move as the sheet width regulating member 44 is moved in the width direction W.
The scale label 69 is further ruled with a plurality of scale lines 71 on a right side or a left side of the dividing line 70. Furthermore, a character string 72 is described under each scale line 71 in
Each scale line 71 is drawn at a position to which the outer surface 67 of the sheet width regulating member 44 is to be adjusted to bring the regulating width of the sheet width regulating members 44 to a target width. The target width is a width of a sheet(s) whose size and orientation indicated by the character string 72 located just outside the corresponding scale line 71. Naturally, the scale lines 71 on the right side of the dividing line 70 are drawn based on the thickness (a thinner one) of the sheet width regulating member 44 on the right side relative to the shoulder portion 68. The scale lines 71 on the left side of the dividing line 70 are drawn based on the thickness (a thicker one) of the sheet width regulating member 44 on the left side relative to the shoulder portion 68.
Using the outer shape of each sheet width regulating member 44 and the scale label 69 mentioned above can provide the following advantages. Since the scale lines 71 are drawn based on the outer surface of the sheet width regulating member 44, not based on the inner surface, it is easy for a user to visually recognize a target for positioning of the sheet width regulating member 44. This is because a user who stands on the front side (on the F side in
Furthermore, a scale line conformal to the shape of the shoulder portion 68 of the sheet width regulating member 44 may be drawn across both sides of the dividing line 70. Such a scale line cannot be adjusted to the inner surface of the sheet width regulating member 44 because this inner surface is linear. Therefore, even a user who has less experience with the image forming apparatus 1 is less likely to erroneously adjust the sheet width regulating member 44. It is to be noted that the dividing line 70 is not indispensable.
According to the present embodiment explained in detail above, there are provided the sheet width regulating members 44 on the manual feeding tray 40 and the sheet width regulating members 46 on the auxiliary tray 45 as the members used for sheet-width regulation on the manual feeding tray 40. The sheet width regulating members 44 are connected to the corresponding sheet width regulating members 46 through the link members 47 to enable simultaneous adjustment of the regulating width of the sheet width regulating members 44 and the sheet width regulating members 46.
This can provide the following advantages. One advantage is that the sheet width regulating can be performed both on the manual feed tray 40 and on the auxiliary tray 45. Accordingly, even if the sheet width regulating members 44 and the sheet width regulating members 46 are each small in size, the total size of the sheet width regulating members 44 and 46 enables the width regulating over a relatively wide area with respect to the sheet longitudinal direction L. This allows reliable sheet-width regulating and less causes skewed feeding. Since the sheet width regulating members 46 are particularly placed on the auxiliary tray 45, they regulate the sheet width on a just upstream side of the manual sheet feeding roller 41 corresponding to a subsequent sheet feeding member. Thus, the sheet width regulating members 46 largely contribute to the sheet skew preventing function. According to the image forming apparatus 1 in the present embodiment configured as above, there can be realized the sheet feeder capable of properly feeding a sheet(s) stacked on the manual feeding tray 40 without causing sheet skewing even where the sheet feeder has an apparatus structure adapted to downsizing, and the image forming apparatus 1 using the sheet feeder.
As another advantage, it is easy for a user to perform an operation of adjusting the regulating width of the sheet width regulating members 44. Even if the sheet width regulating members 44 and the sheet width regulating members 46 are each small in size, the total size of the sheet width regulating members 44 and 46 is large enough to be conspicuous. As still another advantage, the sheet width regulating members 44 placed on the manual feeding tray 40 protruding from the main body 20 makes it easy for a user to reach the sheet width regulating members 44.
According to the present embodiment described above, there are provided the sheet feeder capable of properly feeding a sheet(s) stacked on the tray without causing sheet skewing even if the apparatus structure is adapted to downsizing, and the image forming apparatus using the sheet feeder.
The present embodiment is a mere example and does not give any limitations to the present invention. Thus, the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. For instance, the image forming apparatus 1 shown in
In the sheet feeder configured as above, furthermore, it is preferable that the link member has: a first end attached to one of the first width regulating member and the second width regulating member so that the link member is rotatable about an axis parallel to the sheet width direction at the first end and is fixed to the width regulating member in the sheet width direction; and a second end attached to the other one of the first width regulating member and the second width regulating member so that the link member can perform sliding movement in a sheet feeding direction at the second end and is fixed to the other width regulating member in the sheet width direction. Accordingly, the link member configured as above can deal with both interlocking of the first width regulating member and the second width regulating member in width-direction movement and changes in distance between the first width regulating member and the second width regulating member in association with opening/closing operations of the sheet stacking tray.
In the above case, additionally, it is preferable that the second end of the link member includes a rounded portion formed in a convex shape located in contact with one of the sheet stacking tray and the auxiliary tray, the one of the sheet stacking tray and the auxiliary tray includes a guide groove in a position within a range where the rounded portion can contact the guide groove during the sliding movement, the guide groove being configured to guide the regulating width changing operation of the first width regulating member or second width regulating member, and the convex shape of the rounded portion has a curvature of radius larger than a groove width of the guide groove. With the above configuration, even when the rounded portion moves across the guide groove in the sliding movement, the rounded portion does not deeply fall into the guide groove. Thus, the sliding movement is performed smoothly. This enables the opening/closing operation of the sheet stacking tray without difficulty.
As an alternative to the foregoing, preferably, the link member has: a first end attached to one of the first width regulating member and the second width regulating member so that the link member is rotatable about an axis parallel to the sheet width direction at the first end and is fixed to the width regulating member in the sheet width direction; and a second end attached to the other one of the first width regulating member and the second width regulating member so that the link member is rotatable about an axis parallel to the sheet width direction at the second end and is fixed to the other width regulating member in the sheet width direction, and a distance between the first end and the second end is variable. This configuration can also deal with both interlocking of the first width regulating member and the second width regulating member in width-direction movement and changes in distance between the first width regulating member and the second width regulating member in association with the opening/closing operations of the sheet stacking tray.
In the sheet feeder configured as above, preferably, the sheet stacking tray is provided with a resistance member configured to generate higher operating resistance of the first width regulating member in the regulating width changing operation than operating resistance of the second width regulating member in the regulating width changing operation. The “resistance” used herein means frictional resistance to mechanical movement of a component, not electrical resistance. The existence of the resistance member can prevent the first width regulating member from unintentionally moving due to turbulence or unstable motion of a sheet(s) at the time of start of sheet feeding. Since the resistance member is provided on the sheet stacking tray side, resistance properties to machine vibrations transmitted from the main body to the sheet stacking tray has been improved. In contrast, the operating resistance of the second width regulating member on the auxiliary tray side is low. Thus, the second width regulating member can accompany well the movement of the first width regulating member operated by a user.
In the sheet feeder provided with the foregoing resistance member, furthermore, it is preferable that the sheet stacking tray is provided with a width signal output section configured to output a signal representing a regulating width of the first width regulating member. Accordingly, the main body can grasp what sheet width the first width regulating member and the second width regulating member are adjusted to. Further, since the width signal output section is located on the sheet stacking tray side as with the resistance member, any noise due to vibration transmitted from the main body side is less likely to enter the output signal.
In the sheet feeder in the above embodiment, alternatively, it is preferable that the second width regulating member includes a pair of second width regulating members arranged one on each side in the sheet width direction, and each of the second width regulating members has a regulating surface for regulating the side edge of the sheet in the width direction and is provided with a soft contact member projecting from the regulating surface to a sheet side. The second width regulating member is interlocked with the first width regulating member through the link member. Thus, rattles to a certain extent may be caused with respect to an end position of a regulated sheet. Therefore, the contact members are placed on the sheet side to absorb the rattles, thereby enabling excellent width-direction regulating.
In the sheet feeder configured as above, it is preferable that the first width regulating member includes a pair of first width regulating members, one of which is located on a front side of the main body and has an outer surface located outside in the sheet width direction, the outer surface being formed with a specific outer contour portion having different protruding amounts in the sheet width direction according to positions in the sheet feeding direction, and the sheet stacking tray has a stacking surface including an area to be overlapped by the specific outer contour portion, the area being provided with: a scale line described along a shape of the specific outer contour portion, the scale line representing a position to which the specific outer contour portion is to be adjusted when a position of the first width regulating member in the sheet width direction is set to fit sheet size; and a character located in a position to a front side of the main body than the scale line, the character specifying the sheet size indicated by the scale line. Accordingly, when a user operates the first width regulating member, he/she is less likely to wrongly adjust the first width regulating member to the scale line based on the inner surface. Further, during adjustment of the first width regulating member, the character assigned to the scale line to which the first width regulating member is to be adjusted is kept visible without getting under the first width regulating member.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-035162 | Feb 2015 | JP | national |
