JP2853565B2 - Paper tray - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed tray having a paper stacking member on which sheets are stacked and which can swing in the sheet stacking direction.

[0002]

2. Description of the Related Art Conventionally, this type of paper feed tray has been applied to various apparatuses such as an image forming apparatus such as a laser printer and a word processor. For example, the following are known. That is, a sheet stacking member in which sheets are stacked on the upper surface and a pair of shafts or bearing holes each having an axis extending in the left-right direction formed on both left and right side walls erected at right angles to the upper surface on both sides in the sheet conveyance direction. And a paper feed tray body having a bearing hole or a shaft fitted to the shaft or the bearing hole so as to swing about the axis and to be slidable in the axial direction, and formed on a lower surface of the paper stacking member. Formed on the upper surface of the paper feed tray main body facing the paper stacking member, and the paper stacking member can swing about the axis by fitting with the projection or the recess. And a concave portion or a convex portion that is held so as not to slide in the axial direction.

When assembling this type of paper feed tray, first, a pair of shafts or bearing holes formed in the paper stacking member and a pair of bearing holes or shafts formed in the paper feed tray body are mutually connected. Fit. Subsequently, the paper loading member is appropriately slid in the axial direction so that the convex portion and the concave portion are opposed to each other, and then the paper loading member is swung in a direction in which the convex portion and the concave portion approach. Through such an operation, the above-mentioned convex portion and concave portion can be fitted.

[0004]

However, when performing the fitting operation between the convex portion and the concave portion, the convex portion and the concave portion are hidden behind the lower surface of the sheet stacking member and cannot be seen. For this reason, the operator slides the paper stacking member depending on intuition, and swings the paper stacking member in a direction in which the convex portion and the concave portion approach each other at a position where the convex portion and the concave portion are considered to be opposed to each other. ing. Therefore, the assembling work of this type of paper feeding tray requires skill, and a beginner has to adjust the sliding position of the paper stacking member many times until the convex portion and the concave portion are fitted.

Further, a lateral force acts on the convex portion due to a sliding operation during the assembling operation, and the convex portion is damaged. The impact force acts on the projection, and the projection may be damaged. Therefore, the present invention can easily fit the above-mentioned convex portion and concave portion at the time of assembling, and thus can improve the efficiency of the assembling work, and furthermore, the sheet feeding tray without damaging the convex portion. Made with the purpose of providing.

[0006]

According to a first aspect of the present invention, there is provided an image forming apparatus, comprising: a plurality of sheets stacked on an upper surface; and left and right erected at right angles to the upper surface on both sides in a sheet conveying direction. A paper stacking member having a pair of shafts or bearing holes formed on both side walls and having an axis extending in the left-right direction. The shaft or bearing hole can swing about the axis and can slide in the axis direction. A paper feed tray body having a bearing hole or a shaft that fits in, a convex portion or a concave portion formed on the lower surface of the paper stacking member, and formed on the upper surface of the paper feed tray main body facing the paper stack member; By fitting the projection or the recess, the sheet stacking member can swing about the axis, and a recess or a projection that holds the sheet stacking member non-slidably in the axial direction. The protrusions and recesses are Fitted with each other within approximately a predetermined range in which the sheet stacking member is rocked in accordance with the load of the paper, it is configured to a size which deviates when pivoted beyond its predetermined range,
When the paper stacking member slides in one of the axial directions in a state where the protrusion and the recess are disengaged from each other, the other shaft and the bearing hole are disengaged, and the paper stacking member is disengaged. When the side wall of the paper stacking member slides to the other side in the axial direction and the side wall of the paper stacking member substantially abuts on the paper feed tray main body, the tip of the pair of shafts has a length that fits the other shaft and the bearing hole. The distance between the pair of bearing holes and the distance between the pair of bearing holes are set, and when the side wall of the sheet stacking member substantially abuts on the sheet feed tray, the convex portion and the recessed portion cause the sheet stacking member to swing. Accordingly, they are formed at predetermined positions substantially opposed to each other so as to be fittable with each other.

Further, the invention according to claim 2 is characterized in that at least one of the convex portion and the concave portion is provided when the sheet stacking member swings from the predetermined position in a direction in which the convex portion and the concave portion come close to each other. An inclined surface that contacts the other of the concave portion or the convex portion and slides the paper stacking member in a direction in which a side wall that is in contact with the paper feed tray main body is separated, and the paper stacking member is arranged in accordance with the inclined surface. The paper feed tray according to claim 1, wherein the protrusion and the recess are fitted by sliding.

Further, the invention according to claim 3 is characterized in that the convex portion comprises a pair of flat plates provided to face each other, and a reinforcing plate for connecting between the flat plates. The gist is the paper feed tray described in No. 1.

[0009]

According to the first aspect of the present invention,
It can be assembled as follows. First, the paper loading member and the one shaft of the paper feed tray main body are fitted with the bearing hole, and the paper loading member is slid to the one side. Then, the other shaft and the bearing hole face each other without fitting. Subsequently, when the sheet stacking member is slid to the other side, the other shaft and the bearing hole are fitted, and the side wall of the sheet stacking member substantially abuts on the paper feed tray main body. In this state, the convex portion and the concave portion substantially face each other at a predetermined position where they can be fitted to each other. Then, the convex portion and the concave portion can be fitted only by swinging the sheet stacking member from the predetermined position in the direction in which the convex portion and the concave portion approach each other.

According to the second aspect of the present invention, at least one of the convex portion and the concave portion has an inclined surface, and when the sheet stacking member swings in the direction in which the convex portion and the concave portion come close to each other, the inclined surface is inclined. The convex portion and the concave portion are fitted by sliding the sheet stacking member on the surface. For this reason, the side wall of the sheet stacking member is slightly separated from a state in which the side wall substantially abuts on the sheet feeding tray main body, and the sheet stacking member swings smoothly without interference with the sheet feeding tray.

Further, according to the third aspect of the present invention, the convex portion includes a pair of flat plates provided to face each other, and a reinforcing plate for connecting the flat plates. The projection configured in this way has extremely good strength, and is not easily damaged even when stress is applied in the sliding direction of the sheet stacking member. For this reason,
It is also possible to prevent the impact force from being applied from the outside or the breakage of the convex portion during the assembling work of the sheet feeding tray. In addition, the fitting of the convex portion and the concave portion allows the position of the sheet stacking member in the left-right direction to be accurately regulated, so that the image forming position on the sheet can be made accurate.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view schematically showing a configuration of a laser printer 1 according to an embodiment to which the inventions of claims 1 to 3 are applied. As shown in the figure, the laser printer 1 of the present embodiment
A paper feed tray 3 is detachably provided on the upper surface of the rear part (left side in the figure) of the main body cover 2. A paper feed roller 4 and a holder 5 that is pressed against the paper feed roller 4 are provided in a mounting portion of the paper feed tray 3 of the laser printer 1, and the paper P stacked on the paper feed tray 3 (FIG. 2). Are separated and transported one by one from the top one.

The paper P transported one by one by the paper feed roller 4 is further transported by a transport roller pair 6 and sent to a developing unit 9 having a photosensitive drum 7 and a transfer roller 8. The developing unit 9 is further provided with a toner cartridge 11 for holding the toner and a developing device 13 to which the toner is supplied from the toner cartridge 11, and the image corresponding to the laser light 19 emitted from the scanner unit 17 is formed. Formed on paper P. Further, the sheet P discharged from the developing unit 9 is conveyed to a fixing unit 23 having a heating roller 21 and a pressing roller 22, and subsequently discharged to a sheet discharge tray 25 via a sheet discharge roller 24.

Next, below the developing unit 9, the above-described scanner unit 17 having a laser beam generator 30, a lens 31, and a reflecting mirror 32 is provided.
3, 35 and a power supply unit 37 are provided. The scanner unit 17 emits a laser beam 19 according to image data transmitted from an external device such as a computer (not shown). Then, an electrostatic latent image corresponding to the image data is formed on the surface of the photosensitive drum 7 charged in advance by the charger 39 provided in the developing unit 9. Subsequently, after the developing device 13 visualizes the latent image with the magnetized powder toner, the developing device 13 transfers the toner image to the paper P supplied between the photosensitive drum 7 and the transfer roller 8. . Further, the fixing unit 23 applies heat and pressure to the transferred toner image so that the paper P
To fix the toner image.

FIG. 2 is a longitudinal sectional view showing the structure of the sheet feeding tray 3, and FIG. 3A is a transverse sectional view thereof. Note that FIG. 2 corresponds to a cross section taken along line AA in FIG. 3A, and FIG. 3A corresponds to a cross section taken along line BB in FIG. Also,
FIG. 3B is an enlarged view of the vicinity of the convex portion 51 and the concave portion 61 in FIG.

As shown in FIG. 2, a paper receiving plate 41 as a paper stacking member is provided in the paper feed tray 3 at the upstream end in the paper transport direction so as to be swingable about shafts 41a and 41b (FIG. 3). , And is biased upward (to the right in the figure) by a spring 42. The paper feed roller 4 is disposed to face the downstream end of the paper receiving plate 41 in the paper transport direction, and has the following configuration. That is, a feed roller 45 that is formed in a D-shaped side cross section including a circumferential contact surface 4a that contacts the paper P and a non-contact surface 4b that does not contact the paper P, and that rotates integrally with the drive shaft 43, A feed collar 48 that loosely fits on the drive shaft 43 and presses the paper P toward the holder 5 by its own weight. At least the contact surface 4a of the feed roller 45 has a large friction coefficient such as rubber. The collar 48 is made of a slippery member having a significantly smaller coefficient of friction than rubber. The drive shaft 43 rotates intermittently via a drive motor and a transmission gear mechanism (not shown).

Further, near the downstream end of the paper feed tray 3 in the transport direction, a holder 5 having a separation pad body 5a having a large frictional force adhered to the surface thereof is provided so as to be movable up and down in the radial direction of the paper feed roller 4. It is urged by a spring 50 in a direction in which it comes into contact with the paper feed roller 4. When the non-contact surface 4b of the paper feed roller 4 faces, the separation pad body 5a
The raised position of the holder 5 is regulated by the sheet feeding collar 48 so as not to come into contact with the holder b.

Here, the paper feeding operation by the paper feed roller 4 will be described. When a print command is input to the laser printer 1 and a paper feed command is output from the control boards 33 and 35,
The drive motor (not shown) operates to feed the paper feed roller 4 to the paper P.
One rotation in the transport direction (the direction of arrow F in FIG. 2). Due to this rotation, the sheet P at the uppermost position among the sheets P stacked on the sheet feed tray 3 comes into contact with the contact surface 4a of the sheet feed roller 4 and is pressed and sandwiched between the sheet P and the separation pad body 5a to form only one sheet. It is separated and transported in the transport roller pair 6 direction. Each time the paper P is transported, the spring 42 swings the paper receiving plate 41 in the direction of the paper feed roller 4, and the top surface in the transport direction of the uppermost paper P stacked on the paper receiving plate 41 is fed. Color 48
Abut.

Next, the shafts 41a, 41b of the sheet receiving plate 41
A convex portion 51 is formed on the lower surface in the vicinity of the paper receiving plate 41.
A concave portion 61 is formed on the upper surface of the paper feed tray main body 60 for supporting the same via the shafts 41a and 41b. The concave portion 61 includes a groove portion 62 of the paper feed tray main body 60 and a fitting piece 63 protruding around the groove portion 62. The groove portion 62 is formed to be long in the swinging direction of the convex portion 51 in the sheet loading state of the sheet receiving plate 41, and is formed on both left and right sides of the groove portion 62 (both sides in a direction orthogonal to the swinging direction, that is, the shaft 41).
side pieces 63a, 63 of the fitting pieces formed on the (a, 41b side).
b also extends long in the swinging direction. The protruding portion 51 includes a pair of flat plates 51a and 51b extended similarly in the swing direction on both left and right sides as described above, and a pair of reinforcing plates 51c and 51 connecting the flat plates 51a and 51b at both ends in the swing direction.
d (FIG. 2), it is formed in a square shape parallel to the lower surface of the sheet receiving plate 41, that is, a frame shape.

The dimension between the outer surfaces of the pair of flat plates 51a, 51b is formed to substantially match the dimension between the inner surfaces of the side pieces 63a, 63b. For this reason, the pair of flat plates 51a and 51b is turned into side pieces 63a and 63
While being able to swing in the swinging direction while contacting the inner side surface of the sheet b, the movement of the sheet receiving plate 41 in the left-right direction, that is, the direction orthogonal to the sheet conveying direction is prohibited.

Further, as can be seen from FIG. 2, the sheet receiving plate 41 swings beyond a predetermined range in which the sheet receiving plate 41 swings according to the stacked amount of the sheets P (for example, beyond the position where the sheet feeding roller 4 is disposed). Then, the fitting between the convex portion 51 and the concave portion 61 is released. On the other hand, the above-mentioned shafts 41a and 41b are formed on the right and left side walls 41d and 41e, which are erected at right angles on both sides of the upper surface of the sheet receiving plate 41 in the sheet conveying direction.
From the paper feed tray body 6
The bearing portions 6 as bearing holes into which the shafts 41a and 41b are slidably and slidably fitted in the axial direction are provided on the left and right side walls of the shaft 0.
0a and 60b are formed respectively.

Dimension L between the tips of a pair of shafts 41a and 41b
1 (FIG. 3) is formed to be larger than the dimension L2 between the bearing portions 60a and 60b. The dimension L3 between the outer side surface of the right side wall 41d and the tip of the left shaft 41b is formed to be substantially the same as or slightly smaller than L2. When the convex portion 51 and the concave portion 61 are fitted, a predetermined distance a is provided between the right side wall 41d of the sheet receiving plate 41 and the bearing portion 60a, and a predetermined interval a is provided between the left side wall 41e and the bearing portion 60b. A predetermined interval b opens. Note that the length of the shaft 41b is shorter than the interval a.

Further, as shown in FIG.
The outer edges of the a and 51b and the inner edges of the side pieces 63a and 63b are chamfered to form inclined surfaces 51e and 63e. Then, the inclined surfaces 51e, 63
The sum c of the widths of e in the left-right direction is substantially the same as or larger than the predetermined interval b.

The dimension L4 between the left bearing portion 60b and the upper end of the inclined surface of the left side piece 63b is substantially the same as the dimension L5 between the outer surface of the left side wall 41e and the downstream of the inclined surface of the left flat plate 51a. Or smaller than that by the difference between c and b. To assemble the paper feed tray 3 configured as described above, FIG.
The paper receiving plate 41 with respect to the paper feed tray body 60 as shown in FIG.
First, the right shaft 41a is fitted to the bearing portion 60a as shown in FIG. 5, and the right side wall 41d of the paper receiving plate 41 is attached to the bearing portion in a state where the paper receiving plate 41 is stood at a steeper angle than the normal sheet loading state (FIG. 2). When it is slid in the direction approaching 60a, since L2 <L3 or L2 ≒ L3, the left shaft 41b and the bearing 60
b face each other in a state where they have not yet been fitted (shown by a two-dot chain line in FIG. 5). In this state, as shown by a two-dot chain line in FIG.
Since the paper receiving plate 41 stands at a steep angle, the convex portion 51 is located above the concave portion 61 and has not yet been fitted.

Subsequently, when the sheet receiving plate 41 is slid in the direction of the left shaft 41b, the shaft 41b and the bearing portion 60b are fitted. When the left side wall 41e slides until the left side wall 41e contacts the bearing portion 60b, the convex portion 51 is located substantially above the concave portion 61 so as to oppose it. In this state (indicated by a two-dot chain line in FIG. 4), the paper receiving plate 41 is moved to the position where the paper is loaded in FIG.
Swing around L4 <L5 or L4 ≒ L
5, the convex portion 51 and the concave portion 61 come close to each other and abut on the inclined surfaces 63e and 51e. Further, the rocking of the sheet receiving plate 41 in the same direction causes the inclined surfaces 63e, 51
The convex portion 51 fits into the concave portion 61 while the paper receiving plate 41 slides in the right shaft 41a direction by the action of e. As a result, the paper receiving plate 41 is swingably supported around the shafts 41a and 41b with a gap b provided between the left side wall 41e and the bearing portion 60b, and is movable in the directions of the shafts 41a and 41b. It is forbidden. Thereafter, the paper feed roller 4 is assembled to the paper feed tray main body 60 together with the holder 5 and the shaft 43.

As described above, in the sheet feeding tray 3 of the present embodiment, the sheet receiving plate 41 is projected only by swinging the sheet receiving plate 41 toward the sheet feeding tray main body 60 while the left side wall 41e is in contact with the end face of the bearing portion 60b. The portion 51 and the concave portion 61 can be fitted. That is, the operation of fitting the convex portion 51 and the concave portion 61 hidden on the lower surface of the sheet receiving plate 41 can be easily performed without depending on intuition. Therefore, paper feed tray 3
The assembly work can be streamlined and can be easily performed by a beginner.

In this embodiment, the inclined surfaces 63e, 51
e makes contact with the paper receiving plate 41 on the left side wall 41e.
Slides in a direction away from the bearing portion 60b, so that a predetermined interval b can be provided between the left side wall 41e and the bearing portion 60b. In this manner, by providing the predetermined gaps a and b between the left and right side walls 41d and 41e of the paper receiving plate 41 and the paper feed tray main body 60, the swing of the paper receiving plate 41 can be made sufficiently smooth. it can.

Further, in this embodiment, the convex portion 51 has a very good strength because the cross section is formed in a square shape. Therefore, even if a stress in the left-right direction is applied to the sheet receiving plate 41, the convex portion 51 is not easily damaged. Therefore, it is possible to satisfactorily prevent the projections 51 from being damaged during the assembling operation of the sheet feeding tray 3, and to further facilitate the assembling operation and improve the efficiency. Further, the paper receiving plate 41 is attached to the
In the case where the left and right side walls 41d and 41e are deformed when only the left and right side walls 41d and 41e are deformed, the sheet receiving plate 4 is restricted.
In this embodiment, the right and left positions of the sheet receiving plate 41 are regulated by the convex portions 51 having sufficient strength. Therefore, even if the side walls 41d and 41e are deformed, the image forming position on the sheet is not changed. Can be kept accurate.

It should be noted that the present invention is not limited to the above embodiment, but can be implemented in various modes without departing from the gist of the present invention. For example, in the above embodiment,
Shafts 41a and 41b are protrudingly provided on the left and right sides of the sheet receiving plate 41, and the corresponding bearings 60
a and 60b are formed, but bearing portions are formed on one side or both right and left sides of the sheet receiving plate 41, and the sheet feeding tray main body 60 is formed.
May be provided with a corresponding shaft. Further, a convex portion 51 is provided on the paper feed tray main body 60, and a concave portion 6 is formed on the paper receiving plate 41.
1 may be provided.

[0030]

As described above in detail, according to the first aspect of the present invention, the sheet stacking member is swung to the other side so that the side wall of the sheet stacking member substantially abuts on the paper feed tray main body. The protrusions and the recesses can be fitted only by swinging the loading member in the direction in which the protrusions and the recesses come close to each other. Therefore, the work of fitting the convex portion and the concave portion at the time of assembling is facilitated, and as a result, the work of assembling the paper feed tray is made more efficient, and even a beginner can easily perform the work.

Further, according to the second aspect of the present invention, the side wall of the sheet stacking member is slightly separated from the state in which the side wall of the sheet stacking member substantially contacts the main body of the sheet feeding tray, and the swing of the sheet stacking member can be made sufficiently smooth. Furthermore, according to the third aspect of the present invention, the convex portion has extremely good strength, and is not easily damaged even when stress is applied in the sliding direction of the sheet stacking member. For this reason, it is also possible to satisfactorily prevent the projection from being damaged during the assembling operation of the sheet feeding tray. Therefore, in addition to the effect of the invention described in claim 1, the assembling work of the paper feed tray can be further facilitated and the efficiency can be improved. Further, the right and left positions of the sheet stacking member are accurately regulated, and the image forming position on the sheet can be accurately maintained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating a configuration of a laser printer according to an embodiment.

FIG. 2 is a longitudinal sectional view illustrating a configuration of a paper feed tray of the laser printer according to the embodiment.

FIG. 3 is a cross-sectional view illustrating a configuration of a paper feed tray of the laser printer according to the embodiment.

FIG. 4 is a vertical sectional view for explaining a method of assembling the paper feed tray.

FIG. 5 is a cross-sectional view illustrating a method of assembling the paper feed tray.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Laser printer 3 ... Paper feed tray 41 ... Paper receiving plate 41a, 41b ... Shaft 41d ... Right side wall 41e ... Left side wall 42 ... Spring 51 ... Convex part 51a, 51b ... Flat plate 51c, 51d ... Reinforcement plate 51e, 63e ... Inclined Surface 60: paper feed tray main body 60a, 60b: bearing 61: recess 62: groove 63: fitting piece

Claims (3)

(57) [Claims] 1. A sheet is stacked on an upper surface, and a pair of shafts or bearing holes having an axis extending in the left-right direction is formed on both right and left side walls erected at right angles to the upper surface on both sides in the sheet transport direction. A sheet loading member, a paper feed tray body having a bearing hole or a shaft fitted into the shaft or the bearing hole so as to swing about the axis and slidably in the axial direction, and the sheet loading member. A convex portion or a concave portion formed on the lower surface of the sheet feeding member, and an upper surface of the paper feed tray body opposed to the sheet loading member. And a concave portion or a convex portion capable of swinging in the axial direction so as not to be slidable in the axial direction. The convex portion and the concave portion are configured such that the sheet stacking member swings according to the sheet stacking amount. Within a predetermined range of movement The paper stacking member is configured to be fitted to each other and to be disengaged when it swings beyond a predetermined range, and the paper stacking member slides in one of the axial directions in a state where the protrusion and the recess are disengaged from each other. Then, the other shaft and the bearing hole are disengaged from each other, the paper stacking member slides to the other side in the axial direction, and the side wall of the paper stacking member substantially abuts the paper feed tray main body. When the distance between the tip of the pair of shafts and the distance between the pair of bearing holes is set to a length at which the other shaft and the bearing hole are fitted, the side wall of the sheet stacking member is disposed on the sheet feeding tray. A sheet feeding tray, wherein the convex portion and the concave portion are formed at predetermined positions which are substantially opposed to each other so as to be fitted together with the swing of the sheet stacking member when almost abutting. 2. The method according to claim 1, wherein at least one of the convex portion and the concave portion is formed on the other of the concave portion and the convex portion when the sheet stacking member swings from the predetermined position in a direction in which the convex portion and the concave portion approach each other. An inclined surface that abuts the paper stacking member and slides in a direction in which a side wall that is in contact with the paper feed tray main body is separated, and the paper stacking member slides according to the inclined surface to form the convex portion. 2. The sheet feeding tray according to claim 1, wherein the recess and the recess are fitted. 3. The paper feed tray according to claim 1, wherein the convex portion includes a pair of flat plates provided to face each other, and a reinforcing plate connecting the flat plates.