JP2001097561A - Paper feed cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feed cassette capable of expanding and contracting according to the size of recording sheets contained therein, oscillating an end guide as a bottom plate supporting the recording sheets oscillates, even if the paper feed cassette is expanded, and surely aligning the ends of the recording sheets in a predetermined position. SOLUTION: This paper feed cassette has a cassette expanding/contracting part 2b provided in such a way as to freely expand and contract relative to a cassette body 2a and adjusted in fixed position according to the size of recording sheets P contained in the cassette body 2a, and has also a connecting means for connecting an end guide 28 stood on the cassette expanding/contracting part 2b to a bottom plate 23 supporting the recording sheets P within the cassette body 2a. The connecting means oscillates the sheet alignment face 33 of the end guide 28 as the bottom plate 23 oscillates, regardless of the fixed position of the cassette expanding/contracting part 2b to the cassette body 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed cassette for supplying a recording sheet to an image forming apparatus such as a copying machine or a laser beam printer, and more particularly, to aligning the trailing edge of the recording sheet. The present invention relates to an improvement in a sheet cassette in which an end guide swings according to the remaining amount of recording sheets.

[0002]

2. Description of the Related Art Conventionally, as a paper feed cassette for supplying recording sheets to an image forming apparatus such as a copying machine or a laser beam printer, a bottom plate which can swing freely inside a substantially rectangular cassette main body. There is known a type in which the recording sheet housed in the cassette body is pushed upward by this bottom plate, whereby the uppermost recording sheet is brought into contact with a paper feed roll. I have. In this type of paper cassette,
The position of the recording sheet in the cassette main body is regulated by side guides and end guides, and by changing the standing positions of these side guides and end guides in the cassette main body according to the size of the recording sheet, various sizes are provided. Recording sheets can be handled by one sheet feeding cassette.

However, in this type of paper feed cassette, the number of recording sheets in the cassette body decreases because the bottom plate that supports the recording sheets from below swings so as to lift the leading ends of the recording sheets. Thus, there is a disadvantage that the leading end of the recording sheet aligned with the end guide is retracted from the contact position of the sheet feeding roll, and a sheet feeding error of the recording sheet easily occurs.

In order to solve such a problem, the end guide is swung in accordance with the movement of the bottom plate, and the recording sheet is constantly applied perpendicularly to the end guide to raise the bottom plate. There has been proposed a sheet cassette in which the retraction of the recording sheet due to the above is suppressed (JP-A-8-151134, JP-A-10-134134).
329957).

In the former paper feed cassette disclosed in Japanese Patent Application Laid-Open No. 8-151134, an interlocking plate that slides back and forth in accordance with the swing of the bottom plate is provided at the bottom of the cassette body, and stands upright on the cassette body. An end guide is connected to this interlocking plate. Thus, when the bottom plate swings, the movement is transmitted to the end guide via the interlocking plate, and the end guide swings so that the recording sheet always vertically contacts. On the other hand, in the latter paper feed cassette disclosed in Japanese Patent Application Laid-Open No. 10-329957, an end guide is provided upright on a swinging bottom plate so that the end guide swings together with the bottom plate. It is configured.

[0006]

In recent years, the miniaturization of image forming apparatuses has been rapidly progressing. In particular, in the case of a small laser beam printer used on a table, the installation space is limited in terms of effective use of the desk space. The need for reduction is extremely high. For this reason, the paper feed cassette for supplying the recording sheets to the image forming apparatus is also required to be reduced in size. As one countermeasure, a cassette body is formed based on a frequently used, for example, A4 size recording sheet. In addition, it is conceivable to cope with a recording sheet having a larger size by expanding and contracting the sheet cassette itself. Specifically, an extendable cassette extendable portion is provided for the cassette main body, and the fixing position of the cassette extendable portion with respect to the cassette main body is changed according to the size of the recording sheet accommodated in the paper feed cassette. According to this,
The area occupied by the sheet cassette can always be minimized, and the size of the image forming apparatus can be reduced.

However, in such a retractable paper feed cassette, the size of the paper feed cassette itself expands and contracts according to the recording sheet size, and the distance between the bottom plate and the end guide changes. As described above, it is difficult to link the swing of the end guide to the swing operation of the bottom plate.

That is, when the bottom plate and the end guide are connected by an interlocking plate as in the paper feeding cassette disclosed in Japanese Patent Application Laid-Open No. 8-151134, the length of the interlocking plate corresponds to the smallest size of the paper feeding cassette. When the cassette expansion / contraction part is extended, the interlocking plate cannot be connected to the end guide, and the length of the interlocking plate is determined according to the maximum size of the paper cassette. In this case, when the cassette expansion / contraction part is accommodated in the cassette main body, the interlocking plate projects from the paper feed cassette, which does not meet the demand for downsizing the paper feed cassette.

Further, when the end guide is provided upright on the bottom plate as in the paper feed cassette disclosed in Japanese Patent Application Laid-Open No. 10-329957, it is necessary to extend the bottom plate when the cassette expandable portion is extended. As a result, the structure of the bottom plate becomes complicated. Further, the bottom plate needs to be pivotally supported with respect to the cassette main body in relation to the positioning of the recording sheet. However, when the bottom plate is extended together with the cassette expandable portion, the rear end of the bottom plate swings downward. As a result, the bottom plate and the cassette expandable portion interfere with each other.

The present invention has been made in view of such a problem, and an object of the present invention is to make it possible to expand and contract the size of a sheet feeding cassette according to the size of a recording sheet to be stored. At the same time, even when the paper cassette is extended, the end guide can be swung in accordance with the swing of the bottom plate supporting the recording sheet, and the leading edge of the recording sheet is reliably aligned with a predetermined position. It is an object of the present invention to provide a paper feed cassette capable of performing the following.

[0011]

In order to achieve the above object, a paper feed cassette according to the present invention comprises a cassette body for accommodating recording sheets, and a recording medium rotatably provided and accommodated in the cassette body. A bottom plate that lifts the recording sheet according to the amount of the sheet; and a cassette extender that is provided to be extendable with respect to the cassette body and that has a fixed position that is adjusted according to the size of the recording sheet housed in the cassette body. And an end guide that is erected on the cassette expandable portion and has a sheet alignment surface that aligns the trailing edge of the recording sheet, and the bottom plate and the end guide are connected regardless of the fixed position of the cassette expandable portion, Connecting means for swinging the sheet alignment surface of the end guide in accordance with the swing of the bottom plate. .

According to such a technical means, even if the size of the sheet feeding cassette is changed by adjusting the fixing position of the cassette expanding / contracting portion with respect to the cassette main body in accordance with the size of the recording sheet, the connecting means can be used. Since the bottom plate and the end guide are connected regardless of the fixing position of the section, the sheet alignment surface of the end guide can be swung in conjunction with the swing of the bottom plate, and the recording sheets accommodated in such a sheet feed tray Can always be applied perpendicular to the sheet alignment surface.

Here, the connecting means expands and contracts according to the amount of expansion and contraction of the cassette expandable portion with respect to the cassette body.
In addition, the bottom plate is provided so as to be swingable with respect to the cassette body, while the end guide is provided upright with respect to the cassette expandable portion. In consideration of the above, such a connecting means is provided as follows, namely, a main body side rod slidably provided on the cassette main body and moved by the bottom plate, and a sheet of the end guide provided slidably on the cassette expandable portion. A telescopic part-side rod that swings the alignment surface, and a connecting rod that connects the main body-side rod and the telescopic part-side rod and disconnects the two when adjusting the fixing position of the cassette telescopic part. Is preferred.

Further, since the end guide is erected on the cassette extendable portion, it is necessary to disconnect the bottom plate from the end guide when changing the fixing position of the cassette extendable portion with respect to the cassette body. Is performed separately, the operation of changing the size of the paper feed cassette becomes complicated. Therefore, from this point of view, locking means for determining the fixing position of the cassette extendable portion with respect to the cassette body is provided, and by operating the lock means, the fixed state of the cassette body and the cassette extendable portion is released, and the connecting rod It is preferable that the connection between the main body side rod and the telescopic part side rod is disconnected.

Further, from the viewpoint that recording sheets of various sizes can be set in the sheet feeding cassette of the present invention, the end guide for aligning the trailing edge of the recording sheet is provided with respect to the cassette expanding / contracting portion. A base member is provided so as to be movable up and down, and a sheet regulating member having the sheet alignment surface and swingably provided with respect to the base member. It is preferable to have interlocking claws that fit together. According to this structure, the movement of the bottom plate is transmitted to the sheet regulating member by engaging the interlocking claw of the sheet regulating member with the telescopic portion side rod irrespective of the standing position of the base member with respect to the cassette extending and contracting portion. Therefore, even when recording sheets of various sizes are set in the sheet feeding cassette, and the sheet feeding cassette expands and contracts according to the size and the standing position of the end guide changes, the sheet regulating member is provided. It is possible to swing the aligned sheet alignment surface with the bottom plate.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a paper feed cassette according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view schematically showing a small laser beam printer (hereinafter, referred to as “LBP”) on which a sheet cassette according to the present invention is mounted. In the figure, reference numeral 11 denotes a photosensitive drum, reference numeral 12 denotes a charging roll for uniformly charging the photosensitive drum 11 to a predetermined background potential, and reference numeral 13 denotes a photosensitive beam modulated by a light beam according to image information. A laser beam scanner (ROS) for exposing the body drum 11, reference numeral 14 denotes a developing device for developing the electrostatic latent image formed on the photoconductor drum 11 by exposure with toner, and reference numeral 15 denotes a developing device on the photoconductor drum 11. A transfer roll for transferring the visualized toner image onto the recording sheet P;
Reference numeral 16 denotes a cleaner for removing residual toner from the photosensitive drum 11. These devices except the ROS 13 and the transfer roll 15 are integrated as a print cartridge 10 and a front cover 1 a provided on the printer housing 1.
By pulling it open (to the left in the drawing), it can be easily replaced.

The recording sheet P is supplied from a paper feed cassette 2 stored in a lower portion of the printer housing 1 or a manual feed tray 5 provided on the front side of the printer housing 1 to the inside of the printer, specifically, the photosensitive drum 11. Is supplied to a transfer position between the transfer roller 15 and the transfer roller 15. The paper feed cassette 2 is configured to be set by being pushed into the lower part of the printer housing 1 from the front side.
A pickup roll 20 and a paper feed roll 21 for pulling out the recording sheets P stored in the cassette 2 are arranged side by side at an upper portion of the cassette 2. Further, on the paper feed cassette 2 side, a retard roll 22 that faces the paper feed roll 21 to prevent double feeding of the recording sheet P, and a bottom plate 23 that pushes up the recording sheet P toward the pickup roll 20
Are arranged.

On the other hand, the manual feed tray 5 is provided as a part of the front cover 1a of the printer so as to be openable and closable. When used, the recording sheet is placed on the manual feed tray 5 pulled down as shown in FIG. P is set, and only the leading end of the recording sheet P is inserted into the manual feed port 50 formed by opening the manual feed tray for use. Immediately inside the manual paper feed port 50, a paper feed roll 51 and a retard pad 52 that presses against the paper feed roll 51 are provided. Are separated one by one and supplied to the toner image transfer position.

The recording sheet P supplied from the paper feed cassette 2 or the manual feed tray 5 in this manner is transferred to the transfer roll 1
After the registration with respect to the transfer timing of the toner image is performed by the registration roller 17 disposed before the transfer roller 5, the toner image is fed between the photosensitive drum 11 and the transfer roller 15, and image information is recorded on the recording sheet P. The corresponding toner image is transferred. Then, the recording sheet P on which the toner image has been transferred is inserted into the fixing device 6 to fix the toner image, and then passes through a discharge roller 18 to a discharge tray 1b provided on an upper portion of the printer housing 1 in a face. It is discharged in the down state. Reference numeral 19 in FIG. 1 denotes a sheet reversing path for double-sided printing, which is configured to pull back the recording sheet P discharged from the fixing device 6 and re-feed it to the registration roll 17.

FIG. 2 is a perspective view showing details of the structure of the paper feed cassette 2. As shown in FIG. The paper feed cassette 2 is formed in a substantially rectangular shape whose upper part is opened, and a front panel 24 which forms a part of the appearance of the printer housing 1 and also functions as a handle is mounted on the front side. I have. The above-mentioned bottom plate 23 is provided inside the concave space 25 in which the recording sheet P is stored. The bottom plate 23 is swingably provided around the support shaft 26 and is stored in the concave space 25. The leading end of the recording sheet P is lifted toward the pickup roll 20 described above. The swing of the bottom plate 23 is performed by a motor (not shown). When the sheet cassette 2 is pushed into the printer housing 1, the bottom plate 23 is moved according to the amount of the recording sheets P stored in the sheet cassette 2. Rise,
The uppermost recording sheet P stops at a position where it comes into contact with the pickup roll 20. FIG. 2 illustrates a state in which the bottom plate 23 is raised for convenience of description, and the recording sheet P is omitted to clearly show the bottom plate 23 and its peripheral devices.

In order to align the recording sheet P with a predetermined position in the sheet feeding cassette 2 and to prevent the recording sheet P from being skewed at the time of sheet feeding, the concave space 25 has a side edge corresponding to the recording sheet P. A side guide 27 that is in contact and an end guide 28 that is in contact with the rear edge are provided.
Since the LBP shown in FIG. 1 employs center registration for transporting the recording sheet P with reference to the center in the width direction of the recording sheet P, the paper feed cassette 2 is provided with a bottom plate 23 from both sides. A pair of side guides 27, 27 are provided so as to be sandwiched between them, and in order to correspond to recording sheets P of various sizes, these side guides 27 can adjust the standing position thereof along the width direction of the recording sheet P. Has become. Further, since the side guide 27 advances and retreats in the sheet feeding cassette 2 along the width direction of the recording sheet P, the notch 29 having a size corresponding to the amount of advance and retreat of the side guide 27 is formed in the bottom plate 23.
Are formed, and the side guide 27 is
Through the paper cassette 2. Reference numeral 30 in the drawing denotes a release lever of a lock mechanism that regulates the standing position of the side guide 27.

On the other hand, the end guide 28 is configured so that its standing position can be adjusted along the sheet feeding direction of the recording sheet P, and the bottom plate 23 also prevents interference with the end guide 28. A notch 31 is formed. At the bottom of the paper feed cassette 2, a rack 32 having multi-stage teeth is formed along the paper feed direction of the recording sheet P, and the end guide 28 is engaged with the rack 32 to be at a specific standing position. It is fixed. Further, the end guide 28 is provided with a sheet aligning surface 33 that abuts against and aligns the trailing edge of the recording sheet P. The sheet aligning surface 33 swings in accordance with the elevation of the bottom plate 23. However, care is taken so that the trailing edge of the recording sheet P always abuts vertically. For this reason, the number of recording sheets P stored in the sheet cassette 2 decreases,
Even when the leading end of the bottom plate 23 rises to the vicinity of the pickup roll 20, the recording sheet P does not slip down on the bottom plate 23 toward the end guide 28, and the recording sheet P on the bottom plate 23 does not slip.
Can always be brought into contact with the pickup roll 20 in an appropriate state.

On one side of the sheet cassette 2 on which the retard roll 22 is provided, the recording sheet P pulled out from the sheet cassette 2 by the sheet roll 21 and the retard roll 22 is directed to the upper image forming section. A guide plate 34 for guiding the guide is provided. The guide plate 34 is formed in a concave shape so as to change the traveling direction of the recording sheet by approximately 90 °, and its longitudinal direction (the width direction of the recording sheet).
From the notch window formed at the approximate center of the retard roll 2
2 is exposed. The support shaft of the retard roll 22 is covered by the guide plate 34, and when the guide plate 34 is opened, the retard roll 22
Can be exchanged. FIG. 2 shows a state in which the guide plate 34 is closed, that is, a normal use state.

In order to reduce the installation area of the above-mentioned LBP as much as possible, the paper feed cassette 2 is configured to be able to expand and contract according to the size of the recording sheets P to be stored. That is, the paper feed cassette 2 includes a cassette main body 2a in which a bottom plate 23 is swingably disposed and a cassette main body 2a.
and a cassette extendable portion 2b provided to be able to extend and retract with respect to the cassette extendable portion 2b as shown in FIG.
By sliding b with respect to the cassette body 2a,
The size of the concave space 25 accommodating the recording sheet P can be freely adjusted. Therefore, the end guide 28 for aligning the trailing edge of the recording sheet P is provided in the cassette body 2a.
Instead, the cassette 32 extends and retracts with respect to the cassette extendable portion 2b, and a rack 32 that regulates the standing position of the end guide 28 is also formed in the cassette extendable portion 2b.

In the paper feed cassette 2 of this embodiment, the size of the paper feed cassette 2 is configured to be adjustable in three stages, and is provided in a concave space 25 as shown in FIG. By operating the lock mechanism provided, the size can be changed. The lock mechanism includes a three-stage locking hole 3a provided in the cassette main body 2a along the sliding direction of the cassette expansion / contraction portion 2b, and a lock button provided on the cassette expansion / contraction portion 2b and fitted in the locking hole 3a. When the lock button 3b fitted in the locking hole 3a is pressed down from above, the lock button 3b comes out of the locking hole 3a, and the cassette main body 2a and the cassette elastic portion 2b are connected to each other. The locked state between them is released, and the cassette expandable portion 2b can be slid with respect to the cassette main body 2a as indicated by a white arrow in FIG. When the lock button 3b fits into one of the locking holes 3a as a result of sliding the cassette expansion / contraction part 2b, the cassette expansion / contraction part 2b is fixed to the cassette main body 2a at that time, and The size of is fixed.

Next, connection means for transmitting the swing of the bottom plate 23 to the sheet alignment surface 33 of the end guide 28 will be described. As described above, in this paper feed cassette 2, since the cassette expandable portion 2b slides with respect to the cassette body 2a to change the size of the concave space 25, the bottom plate 23 and the end guide 28 are directly connected. In this case, it becomes impossible to adjust the size of the sheet cassette 2. Therefore, in the sheet cassette 2 of this embodiment, the sheet alignment surface 33 of the end guide 28 can be swung in accordance with the swing of the bottom plate 23 irrespective of the fixed position of the cassette expandable portion 2b with respect to the cassette body 2a. Possible connecting means are provided.

As shown in FIGS. 4 and 5, the connecting means comprises a main body side rod 35 slidably provided at the bottom of the cassette main body 2a, and a telescopic means provided slidably with respect to the cassette telescopic part 2b. And a connecting rod 37 for connecting the main body side rod 35 and the telescopic part side rod 36 to each other. The main body side rod 35 has a hook-like arm projecting from the rear end of the bottom plate 23. 38 is hooked. Further, a rack with which the end guide 28 is engaged is formed on the telescopic portion side rod 36. Since the connecting rod 37 is engaged with the main body rod 35 and the telescopic part side rod 36 from the back side of the sheet cassette 2, it is not exposed to the concave space 25. Not drawn.

As shown in FIG. 4, when the number of recording sheets P in the concave space 25 decreases and the tip of the bottom plate 23 swings upward, the support shaft 26 serving as the swing center of the bottom plate 23 is rotated. The rear end of the bottom plate 23 moves to the front side in the concave space 25 in view of the positional relationship with the above, so that the hook-shaped arm 38 projecting from the rear end of the bottom plate 23 attaches the main body side rod 35 to the cassette. Body 2
It will slide toward the front of the a side. Since the telescopic portion side rod 36 provided in the cassette telescopic portion 2b is connected to the main body side rod 35 by the connecting rod 37, when the bottom plate 23 swings upward, the telescopic portion side rod 36 also moves on the cassette telescopic portion 2b. Is moved to the front side, and the movement of the bottom plate 23 is transmitted to the end guide 28 engaged with the telescopic portion side rod 36. Thus, the sheet alignment surface 33 of the end guide 28 can be swung in accordance with the swing of the bottom plate 23. In addition, the bottom plate 23 drawn by the two-dot chain line in FIG.
The end guides 28 drawn by two-dot chain lines respectively show the state of swinging due to the elevation of the bottom plate 23.

As shown in FIG. 5, the connecting rod 37 is formed in a leaf spring shape, and one end of the connecting rod 37 is fixed to the telescopic portion side rod 36, and the other end is connected to the main body side rod 35. On the other hand, it is elastically contacted from below. On the lower surface side of the main body side rod 35, three locking grooves 39a, 39b, 39c corresponding to three-stage fixing positions of the cassette expandable portion are formed. It is configured to fit. Therefore, FIG.
As shown in (a), the locking groove 39a of the main body side rod 35
When the free end of the connecting rod 37 fitted to the connector is pushed down, the connecting rod 37 comes out of the locking groove 39a to release the connection state between the main body side rod 35 and the connecting rod 37, and when the pressing force is released. The connecting rod 37 fits into one of the locking grooves 39a, 39b, 39c by its own elastic force.

The connecting rod 37 is fixed to a telescopic part-side rod 36 provided for the cassette telescopic part 2b.
Since the main body side rod 35 is provided on the cassette main body 2a side, if the cassette elastic part 2b is pulled out from the cassette main body 2a with the connected state of the connecting rod 37 and the main body side rod 35 being released, the connecting rod 37 becomes The lower surface of the side rod 35 is moved to the rear side, and as shown in FIG. 5B, is fitted into the next engaging groove 39b adjacent to the first engaging groove 39a. Thereby, the cassette body 2a
Can be changed in accordance with the fixed position of the cassette expansion / contraction part 2b with respect to the main body side rod 35 and the expansion / contraction part side rod 36. The swing can be transmitted to the end guide 28 to swing the sheet alignment surface 33.

In the sheet cassette 2, the lock mechanism including the lock button 3b and the locking hole 3a is located between the main body side rod 35 and the telescopic part side rod 36. It passes right below the lock button 3b and fits into the locking groove 39a of the main body side rod 35. That is, the connecting rod 37 formed in the shape of a leaf spring functions to push up the lock button 3b located directly above the lock rod 3b, and pushes the lock button 3b from below into the locking hole 3b.
a, and the free end of the connecting rod 37 is fitted into the locking groove 39a of the main body side rod 35 in a state where the lock button 3b is fitted into the locking hole 3a. Therefore, when the lock button 3b is pressed to change the size of the paper feed cassette 2, the free end of the connecting rod 37 located below the lock button 3b is simultaneously pressed down, and the release of the fixed state of the cassette elastic part 2b is achieved. In addition, the release of the connection between the main body side rod 35 and the telescopic part side rod 36 can be simultaneously performed only by pressing down the lock button 3b. Therefore, if the cassette expansion / contraction part 2b is slid with respect to the cassette body 2a after the lock button 3b is pressed down, the size of the sheet cassette 2 and the connection state of the bottom plate 23 and the end guide 28 accompanying this change can be changed. Can be done at once,
The size of the sheet cassette 2 can be easily changed, and the configuration of the sheet cassette 2 itself is simplified.

FIG. 6 is an exploded perspective view showing the end guide. The end guide 28 includes a base member 40 erected up and down with respect to the cassette extendable and retractable portion 2b, and a sheet regulating member 41 attached to the base member 40 so as to swing freely. Regulator 41
Are provided with the sheet alignment surface 33 described above. The base member 40 includes a base portion 42 that slides on the cassette expandable portion 2b, a support portion 43 erected on the base portion 42,
A pair of release levers 44, 45 protruding from the left and right sides of the support portion 43 in a substantially L-shape, and a cassette is provided on a lower surface of one of the release levers 44 (hereinafter, referred to as a "fixed release lever"). A locking claw 46 (see FIG. 8) that meshes with the rack 32 formed on the extendable portion 2b is formed. Normally, the locking claw 46 is mounted on the rack 3 of the cassette extendable portion 2b.
2, the cassette expansion and contraction portion 2b
The upright position of the end guide 28 on the upper side is fixed. When the distal ends of a pair of release levers 44 and 45 including the release lever 44 are picked, the release lever 44 and the support portion 43 are fixed. Is elastically bent about the coupling position of, and the locking claw 46 formed on the lower surface of the fixing release lever 44 rises from the rack 25 of the cassette expansion and contraction portion 2b. As a result, the fixing of the base member 40 to the cassette elastic part 2b is released, and the entire end guide 28 including the sheet regulating member 41 is moved to the cassette elastic part 2b.
b can be slid. When the external force is removed and the fixing release lever 44 returns to its original position by its elastic force, the locking claw 46 and the rack 25 are engaged again, and the standing position of the end guide 28 can be fixed.

On the other hand, the sheet regulating member 41 is configured to be able to swing about a projection 47 projecting from the support portion 43 of the base member 40. On the back side of the above-mentioned sheet alignment surface 33, there is provided a locking lever 49 that can swing around a support shaft 48, and an interlocking claw 50 protrudes from the lower surface of the locking lever 49. The interlocking claw 50 meshes with a rack engraved on the telescopic portion side rod 36 through a window 60 formed in the base portion 42 of the base member 40, and the interlocking claw 50 and the telescopic portion side rod 36 are engaged with each other.
The locking lever 49 is urged by a spring 61 so that the rack always meshes with the rack. Therefore, FIG.
As shown in FIG. 8, when the telescopic portion side rod 36 slides in accordance with the swing of the bottom plate 23, such movement is transmitted to the sheet regulating member 41 via the interlocking claw 50 that meshes with the telescopic portion side rod 36, and the sheet alignment surface The sheet regulating member 41 provided with 33 swings in accordance with the movement of the bottom plate 23.

A flange portion 62 is provided upright on the locking lever 49. When the base member 40 and the sheet regulating member 41 are assembled, the flange portion 62 is provided.
Are housed inside one of the release levers 45 (hereinafter, this is referred to as an “interlock release lever”). Therefore, in order to change the standing position of the end guide 28, a pair of release levers 4 including the interlock release lever 45 are provided.
4 and 45, the locking lever 49 housed in the interlock release lever 45 is forcibly swung in the direction opposite to the biasing direction of the spring 61, and the interlocking claw 50 is expanded and contracted. The meshing state with the unit side rod 36 is released. That is, the end guide 2 of this embodiment
8, as shown in FIG. 8, a pair of release levers 44, 4
5, when the rack 32 of the cassette extendable portion 2b is disengaged from the locking claw 46, the engagement between the extendable portion side rod 36 and the interlocking claw 50 is also disengaged. Thus, the end guide 28 can be slid with respect to the cassette expansion / contraction part 2b to change its standing position.

Such a change in the standing position of the end guide 28 is made by the user who sets the recording sheets P in the sheet feeding cassette 2. However, when the standing position of the end guide 28 is changed, the user must be careful. From the sheet regulating member 41
The interlocking claw 5 of the end guide 28 is
If the zero and the telescopic portion side rod 36 are engaged, the end plate 28 prevents the bottom plate 23 from being lifted due to the swing range of the sheet regulating member 41. If the bottom plate 23 is forcibly lifted, ,
There is a possibility that the interlocking claw 50 or the telescopic part side rod 36 may be damaged. Therefore, the end guide 28 of this embodiment
Takes measures to prohibit the sheet regulating member 41 from swinging when the release levers 44 and 45 are pinched.

That is, the locking projection 62 is formed on the outer surface of the interlock release lever 45, while the sheet regulating member 41 is formed.
A substantially L-shaped hook 63 that interferes with the locking projection 62 is formed. When the release levers 44 and 45 are held, the locking projection 62 moves slightly upward and interferes with the hook 63. In a state where the sheet alignment surface 33 is vertical, the sheet regulating member 41
Rocking is prohibited. Therefore, when the standing position of the end guide 28 is changed by changing the size of the recording sheet P set in the sheet feeding cassette 2 or the like,
In a state where the end guide 28 is moved forward and backward with respect to the cassette extending / contracting portion 2b, the sheet regulating member 41 is fixed such that the sheet alignment surface 33 is always vertical, and the standing position of the end guide 28 is determined and released. Unless the levers 44 and 45 are opened, the fixing of the sheet regulating member 41 is not released. Accordingly, the interlocking pawl 50 that controls the swing of the end guide 28 can always be engaged with the rack of the telescopic unit side rod 36 in an appropriate state, and the above-described trouble can be avoided.

[0037]

As described above, according to the paper feed cassette of the present invention, the size of the paper feed cassette is changed by adjusting the fixing position of the cassette expandable portion with respect to the cassette body in accordance with the size of the recording sheet. Even if such a size change is made, the sheet alignment surface of the end guide can be swung in conjunction with the swinging of the bottom plate, so that the sheet is accommodated in the sheet feeding tray. The trailing edge of the recording sheet can always be applied perpendicular to the sheet alignment surface, and the leading edge of the recording sheet can be surely aligned with a predetermined position.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an example of an LBP in which a sheet cassette according to the present invention is used.

FIG. 2 is a perspective view illustrating an embodiment of the sheet cassette according to the present invention.

FIG. 3 is a perspective view showing a state of expansion and contraction of a sheet cassette according to the embodiment.

FIG. 4 is a perspective view showing a state in which a bottom plate and an end guide of the sheet cassette according to the embodiment are interlocked.

FIG. 5 is a perspective view showing a connected state of a main body side rod and a telescopic part side rod of the paper feed cassette according to the embodiment.

FIG. 6 is an exploded perspective view illustrating an end guide of the sheet cassette according to the embodiment.

FIG. 7 is a side view showing a state in which an end guide and a telescopic portion side rod are engaged with each other in the paper feed cassette according to the embodiment.

FIG. 8 is a schematic diagram illustrating a state in which an upright position of an end guide is changed in a sheet cassette according to the embodiment.

[Explanation of symbols]

Reference numeral 2: paper feed cassette, 2a: cassette body, 2b: cassette expansion / contraction part, 3a: locking hole, 3b: lock button, 23 ...
Bottom plate, 28: End guide, 33: Sheet alignment surface, 35: Body side rod, 36: Telescopic part side rod

Claims (7)

[Claims] A cassette body for accommodating recording sheets;
A bottom plate that is swingably provided in the cassette main body and lifts the recording sheet according to the amount of the stored recording sheet, and is provided to be expandable and contractible with respect to the cassette main body and is stored in the cassette main body. A cassette expansion / contraction part whose fixed position is adjusted according to the size of the recording sheet, an end guide provided on the cassette expansion / contraction part and having a sheet alignment surface for aligning the trailing edge of the recording sheet; And a connecting means for connecting the bottom plate and the end guide irrespective of the fixed position of the end plate and for swinging the sheet alignment surface of the end guide in accordance with the swing of the bottom plate. 2. The connecting means is provided slidably with respect to the cassette main body and is slidable with respect to the cassette extendable portion while being slidable with respect to the cassette extendable portion. It is characterized by comprising a telescopic part side rod that swings, and a connecting rod that connects the main body side rod and the telescopic part side rod and disconnects both when adjusting the fixing position of the cassette telescopic part. The sheet cassette according to claim 1, wherein: 3. A lock means for determining a fixing position of the cassette extendable portion with respect to the cassette main body is provided, and by operating the lock means, the fixed state of the cassette main body and the cassette extendable portion is released, and the main body side by the connecting rod is connected. The paper feed cassette according to claim 2, wherein the connection between the rod and the rod on the telescopic portion side is disconnected. 4. The lock means comprises: a lock hole provided in the cassette body in multiple stages; and a lock button provided in the cassette expandable portion and selectively fitted into the lock hole of the cassette body. The paper feed cassette according to claim 3, wherein the connecting rod biases the lock button toward the locking hole. 5. An end guide according to claim 1, wherein said end guide includes a base member erected so as to be able to advance and retreat with respect to the cassette extendable portion, and a sheet regulating member provided with said sheet alignment surface and slidably provided with respect to said base member. 4. The sheet feeding cassette according to claim 2, wherein the sheet regulating member has an interlocking claw that engages with the telescopic portion side rod. 6. The base member of the end guide has a locking claw that regulates a standing position of the end guide with respect to the cassette expansion and contraction portion, and has a release lever that separates the locking claw from the cassette expansion and contraction portion. The paper feed cassette according to claim 5, wherein the engagement of the interlocking claw with the telescopic portion side rod is released by operating the release lever. 7. The sheet feeding cassette according to claim 6, wherein a stopper member is provided on the base member of the end guide to prevent the sheet regulating member from swinging when the release lever is operated.