JP4393396B2 - Paper storage device - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper storage device for storing paper used in an image forming apparatus such as a digital copying machine and a laser printer, and more particularly to a display member mechanism for displaying the remaining amount of paper in the paper feeding device. .

  The configuration of a conventional image forming apparatus is shown in FIG. In an image forming apparatus (for example, a printer) 1, when performing an image forming operation, a photosensitive drum 5 that rotates clockwise in the drawing is uniformly charged by a charging unit 4, and an exposure unit (laser scanning unit) based on document image data. Etc.) An electrostatic latent image is formed on the photosensitive drum 5 by the laser beam from 7, and a developer (hereinafter referred to as toner) is attached to the electrostatic latent image by the developing unit 8 to form a toner image.

  The toner is supplied to the developing unit 8 from the toner container 9. The image data is transmitted from a personal computer (not shown) or the like. Further, a static elimination device (not shown) for removing residual charges on the surface of the photosensitive drum 5 is provided on the downstream side of the cleaning device 18.

  The sheet is conveyed from the sheet feeding cassette 10 via the sheet conveyance path 11 and the registration roller pair 12 toward the photosensitive drum 5 on which the toner image is formed as described above, and is transferred by the transfer roller 13 (image transfer unit). A toner image formed on the surface of the photosensitive drum 5 is transferred to a sheet. The sheet onto which the toner image has been transferred is separated from the photosensitive drum 5 and conveyed to a fixing unit 14 having a fixing roller pair 14a to fix the toner image. The sheet that has passed through the fixing unit 14 is conveyed to the upper part of the apparatus by the sheet conveying path 15 and is discharged from the discharge roller pair 16 to the discharge tray 17.

  Next, the configuration of the paper feed cassette will be described. FIG. 8 is a side cross-sectional view of the paper feed cassette 10 and shows a state where the paper feed cassette 10 is viewed from the back side of the paper of FIG. The paper 26 set on the cassette base 25 of the paper feed cassette 10 is applied to a pickup roller 29 provided on the apparatus main body side at a predetermined pressure by a paper stacking plate 28 biased upward by a conical compression spring 27. Pressed. Here, when the copy start button of the image forming apparatus is turned on, the pickup roller 29 and the driving roller 30a of the conveying roller pair 30 are rotationally driven in the direction of the arrow in the drawing.

  The paper 26 set on the paper stacking plate 28 is normally fed by a pickup roller 29 to a plurality of conveying rollers 30 at the upper stage. The plurality of sheets sent to the conveyance roller pair 30 are separated and conveyed toward the sheet conveyance path 11 by the separation roller 30b rotating in the same direction as the stop or drive roller 30a. Reference numeral 31 denotes a rear end cursor for aligning the rear ends of the paper 26, and is provided so as to be movable in the paper transport direction (left-right direction).

  In such an image forming apparatus, a technique of providing a display member for displaying the remaining amount of paper stored inside to prevent the paper from running out during continuous image formation and preventing the image forming process from being interrupted. It has been known. For example, in Patent Document 1, a display device including a curved arm and an arch-shaped display unit is rotatably provided in a paper feed cassette, and the curved arm is moved up and down in accordance with the upper and lower sides of the paper stacking plate, thereby displaying the display unit. A paper feeding device is disclosed that switches the position between a position that can be viewed from the outside and a position that cannot be viewed from the outside.

  Further, Patent Document 2 includes a display component that allows the display member to be visually recognized from the outside, and a movable component that is pivotally supported so that the display component can be moved up and down. A sheet stacking device is disclosed in which a display component sandwiched between U-shaped grooves provided at the other end of the movable component is moved up and down by swinging the movable component. Further, Patent Document 3 discloses a method of solving a malfunction of a display device by engaging a sheet stacking plate and a display component so as to be sandwiched by an arm in the vertical direction.

  However, in the method of Patent Document 1, when the display unit rises from the bottom to the top (the sheet is fully loaded from the state where there is no sheet), when the sheet 26 is replenished, the sheet stacking plate is used by the sheet 26 or the user's hand. Since 28 is pressed against the urging force of the compression spring 27, the display member can be moved without any problem. However, when the display unit descends from top to bottom (gradually descends as the paper is fed from a fully loaded state), the display unit is caught by the housing or the like and does not descend as the paper stacking plate 28 rises. Problems may occur.

  In order to solve this problem, a method of providing a spring member that rotationally biases the display member in a direction to lower the display member so as to reliably follow the movement of the sheet stacking plate 28 can be considered. However, such a spring member must be a highly accurate member having a very low elastic force that does not affect the pressure (feed pressure) for pressing the paper 26 against the pickup roller 29. It is difficult to manufacture and the shape of the display member is complicated.

In addition, in the methods of Patent Documents 2 and 3, although the display member can be reliably prevented from malfunctioning in the vertical direction, vibration and impact are applied from the left and right when the paper storage device is detached from the image forming apparatus main body. In this case, the display member and the movable member may be disengaged. There are also a method to harden the engagement and make it difficult to disengage, or a method to make the engagement portion not disengaged in advance, but in that case, the display member does not operate smoothly, the assembly workability decreases and the parts There was a problem that it led to cost increase.
JP-A-6-21380 JP 10-297793 A JP-A-10-245139

  In view of the above problems, an object of the present invention is to provide a paper storage device having a function of reliably displaying the remaining amount of paper in the paper storage device at a low cost.

  In order to achieve the above object, the present invention includes a paper stacking plate that can be moved up and down in accordance with the load amount of paper, a movable lever that is swingable in conjunction with the lifting and lowering of the paper stacking plate, And a display member that is engaged with the movable lever and displays the remaining amount of paper by moving up and down in conjunction with the swing of the movable lever, and a relationship between the movable lever and the display member. The joint portion is configured such that the movable lever and the display member are sandwiched from each other in the vertical and horizontal directions.

  According to the present invention, in the paper storage device configured as described above, the engaging portion has a predetermined amount of play in the vertical and horizontal directions.

  According to the present invention, in the paper storage device configured as described above, the movable lever is provided with a bifurcated portion including two ribs erected substantially in parallel, and the display member has a substantially U-shaped cross section. A notch portion is provided, and the engaging portion is formed by engaging the bifurcated portion so as to be orthogonal to the notch portion.

  According to the first configuration of the present invention, even if the movable lever or the display member moves in any direction, up, down, left, or right, it is always configured to contact each other at the engaging portion. Even in such a case, the movable lever can be moved smoothly by swinging the movable lever, and there is no possibility that the engagement is disengaged when the engaging portion is shifted to the left or right due to impact or vibration.

  Further, according to the second configuration of the present invention, in the paper storage device of the first configuration, the movable lever and the display member are engaged with each other with a predetermined amount of play in the vertical and horizontal directions. Can be smoothly transmitted to the display member as a driving force in the vertical direction. Further, since the movable lever and the display member can be easily engaged, the assembly workability is improved.

  Further, according to the third configuration of the present invention, in the paper storage device having the first or second configuration, the movable lever is provided with a forked portion and the display member is provided with a notched portion, and the forked portion is separated from the forked portion. By engaging the cutout portion so as to be orthogonal to each other, the structure of the movable lever, the display member, and the engagement portion thereof can be simplified.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a configuration of a paper feed cassette according to an embodiment of the present invention. Portions common to FIG. 8 of the conventional example are denoted by the same reference numerals and description thereof is omitted. In FIG. 1, a sheet stacking plate 28 is provided on a cassette base 25 so as to be vertically movable around fulcrums 32a and 32b. Reference numerals 33a and 33b denote a pair of width alignment cursors for positioning in the width direction of the sheets stacked on the sheet stacking plate 28, and are respectively provided so as to be reciprocally movable in the sheet width direction (arrow AA 'direction in the figure). .

  By moving the width alignment cursors 33 a and 33 b and the rear end cursor 31 according to the size of the stacked paper, the paper is stored in a predetermined position in the paper feed cassette 10. Reference numeral 34 denotes a cassette cover, whose front side (side seen from the direction of arrow B) is exposed to the outside and constitutes a part of the exterior surface of the main body of the image forming apparatus 1 (see FIG. 7).

  A display member 35 that displays the remaining amount of paper in the paper feed cassette 10 is provided at the end of the cassette cover 34. The display member 35 is connected to the paper stacking plate 28 through a movable lever 36 that swings in conjunction with the elevation of the paper stacking plate 28. On both the left and right ends of the paper stacking plate 28, there are provided pressing portions 28a that contact a part of the apparatus main body and push down the paper stacking board 28 when the paper feed cassette 10 is pulled out from the apparatus main body. The configuration of the display member 35 and the movable lever 36 will be described later.

  FIG. 2 is a perspective view of the paper feed cassette 10 as viewed from the direction of arrow B in FIG. A slit-like display window 34a is provided on the surface of the cassette cover 34, and the display portion 35a of the display member 35 (see FIG. 1) is engaged therewith. The display portion 35a slides up and down along the display window 34a so that the remaining amount of paper in the paper feed cassette 10 can be visually recognized from the outside.

  Next, the configuration of the display member 35 and the movable lever 36 will be described in detail. FIG. 3 is an enlarged view of the vicinity of the display member 35 of FIG. The movable lever 36 includes a first arm portion 36b that engages with the display member 35 and a lower portion of the pressing portion 28a of the paper stacking plate 28 from both ends of a support portion 36a that is supported so as to swing up and down with a boss 37 as a fulcrum. And a second arm portion 36c that abuts each other are integrally formed in a crank shape projecting in opposite directions. In addition, a bifurcated portion 38 made up of two ribs 38a and 38b erected substantially in parallel is formed at the tip of the first arm portion 36b. On the other hand, a notch 39 having a substantially U-shaped cross section that is open to the first arm portion 36b is formed in the lower portion of the display member 35.

  The present embodiment is characterized in that the engaging portion J between the first arm portion 36 b and the display member 35 is configured such that the bifurcated portion 38 is engaged so as to be orthogonal to the notch portion 39. With this configuration, the display member 35 is sandwiched from the left and right by the ribs 38 a and 38 b of the bifurcated portion 38, and the first arm portion 36 b is sandwiched from the top and bottom by the top and bottom surfaces of the cutout portion 39. Can be moved smoothly in any direction, and there is no risk of disengagement between the display member 35 and the first arm portion 36b due to impact or vibration in the left-right direction.

  Next, a mechanism in which the display member 35 moves up and down in conjunction with the elevation of the paper stacking plate 28 will be described. 4 and 5 are enlarged side views of the periphery of the movable lever 36 in the paper storage device of the present invention. FIG. 4 shows a state where the paper is fully loaded in the paper feed cassette 10, and FIG. This indicates a state in which no paper is left. For convenience of explanation, the engaging portion J of the display member 35 and the movable lever 36 is shown in a cross section (CC ′ cross section in FIG. 3). In FIG. 4, the paper is not shown.

  When replenishing paper in the paper cassette 10, the paper stacking plate 28 is lowered to the bottom surface of the cassette base 25 by pulling out the paper cassette 10 from the apparatus main body or by manual pressing operation by the user. The second arm portion 36c (see FIG. 3) of the movable lever 36 that is in contact with the lower surface of the stacking plate 28 is also pushed downward. Accordingly, the support portion 36a rotates clockwise with the boss 37 as a fulcrum, and as shown in FIG. 4, the forked portion 38 of the first arm portion 36b is formed on the notch portion 39 provided on the display member 35. Lift the top surface 39a. As a result, the display member 35 slides along the display window 34a, and the display portion 35a moves to the top of the display window 34a, so that the user can see that the sheet is full when viewed from the outside (left side of the drawing). recognize.

  On the other hand, as the paper is fed from the paper feed cassette 10 to the image forming apparatus main body by the pickup roller 29 and the paper on the paper stacking plate 28 decreases, the paper stacking plate 28 is attached with a compression spring 27 (see FIG. 8). Gradually rises with power. Here, the movable lever 36 is designed such that the weight on the first arm portion 36b (see FIG. 3) side of the boss 37 is heavier than that on the second arm portion 36c (see FIG. 3) side. The second arm portion 36c rises following the rise of the lever press 28a, and the support portion 36a rotates counterclockwise with the boss 37 as a fulcrum.

  Accordingly, the first arm portion 36b is also lowered, so that the display member 35 slides along the display window 34a by its own weight, and the display portion 35a moves to the lowermost portion of the display window 34a as shown in FIG. Therefore, the user recognizes that the sheet has run out as viewed from the outside (the left side of the drawing).

  Further, even when the display member 35 is not lowered by its own weight, for example, when the display portion 35a is caught by the display window 34a, the bifurcated portion 38 pushes down the bottom surface 39b of the notch portion 39. Thereby, since the display member 35 is surely lowered along the display window 34a, it is possible to avoid a state in which the sheet runs out even though the display portion 35a is not moved to the lowermost portion.

  Further, in the present embodiment, as is apparent from FIG. 5, in the engaging portion J, the forked portion 38 and the notch portion 39 are engaged with each other with a predetermined amount of play d1 in the vertical direction. This is because the display member 35 moves linearly in the vertical direction, whereas the movable lever 36 swings so as to draw an arc around the boss 37. Therefore, when the play d1 is not provided, the display member 35 is smooth. This is because there is a possibility that it cannot be moved to.

  With the configuration of the present embodiment, out of the rotational force centered on the boss 37, except for the driving force in the vertical direction, it can be released by the play d1, so that only the force necessary for the movement of the display member 35 is smoothly transmitted. be able to. This is particularly effective when the cassette cover 34 is inclined and the display member 35 is desired to be lifted away from the movable lever 36 as in this embodiment. Further, by providing play d1, when assembling the paper feed cassette 10, the display member 35 is inclined and inserted into the display window 34a from the outside (left side of the drawing) and easily engaged with the forked portion 38 of the movable lever 36. Therefore, the assembly workability is also improved.

  Even when the remaining amount of paper is the same, there is a difference in the position of the display portion 35a by the amount of play d1 when the display member 35 is lowered by its own weight and when it is pushed down by the bifurcated portion 38. However, the remaining amount display by the display member 35 is used as a guideline for the sheet replenishment timing by the user, and some error is allowed if there is no risk of running out of sheets during the image forming process. Therefore, the play d1 is preferably set within a range that is allowed as a display error of the remaining amount of paper.

  As shown in FIG. 6, the engaging portion J also has a play d <b> 2 in the left-right direction between the display member 35 and the ribs 38 a and 38 b of the bifurcated portion 38. This facilitates the engagement between the bifurcated portion 38 and the cutout portion 39 during assembly, and allows the display member 35 to be smoothly moved up and down by the rotation of the movable lever 36. Note that the size of the play d2 may be set as appropriate within a range where the above-described effects can be exhibited.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, in the above-described embodiment, the bifurcated portion 38 is configured by the ribs 38a and 38b erected upward. However, if the display member 35 is sandwiched from the left and right, the ribs 38a and 38b are directed downward or horizontally. May be provided. Further, the display member 35 is sandwiched from the left and right by the bifurcated portion 38 of the movable lever 36 and the movable lever 36 is sandwiched from above and below by the cutout portion 39 of the display member 35. May be sandwiched from above and below, and the movable lever 36 may be sandwiched between the display member 35 from the left and right.

  Further, here, the movable lever 36 is rotated counterclockwise due to the difference in weight between the first arm portion 36b side and the second arm portion 36c side. For example, of the sheet stacking plate 28 and the second arm portion 36c, If one of them is engaged so as to sandwich the other in the vertical direction, even if the display member 35 is firmly hooked and the movable lever 36 does not rotate, it can be moved by the lifting force of the paper stacking plate 28. The lever 36 and the display member 35 can be moved.

  Further, the shapes of the display member 35, the movable lever 36, the forked portion 38, and the cutout portion 39 are merely examples, and the specifications of the paper feed cassette 10 include the arrangement of the display window 34a and the movable range of the display member 35. It can be changed as appropriate.

  The present invention includes a paper stacking plate that can be moved up and down in accordance with a stacking amount of paper, a movable lever that is swingable in conjunction with the lifting and lowering of the paper stacking plate, and a movable lever that is engaged with the movable plate. In the paper storage device having a display member that displays the remaining amount of paper by moving up and down in conjunction with the swing of the movable lever, the movable lever and the engaging member of the display member are connected to the movable lever and the display member. Suppose that it was comprised so that it might mutually pinch from the up-down and left-right direction.

  Thus, even when the display member is not movable, the paper storage device that can be smoothly moved by the swing of the movable lever, and further, the engagement is not likely to be disengaged when the engagement portion is shifted to the left or right due to impact or vibration. This can be realized with a simple configuration.

  In addition, since the movable lever and the display member are engaged with each other with a predetermined amount of play in the vertical and horizontal directions, the rotational force of the movable lever can be smoothly transmitted to the display member as a driving force in the vertical direction. This is effective when it is desired to move the display member diagonally up and down. Further, since the movable lever and the display member can be easily engaged, the assembly workability is improved.

  In addition, the movable lever and the display member are provided with a bifurcated portion and a notch portion on the display member, and the bifurcated portion and the notched portion are engaged so as to be orthogonal to each other. The structure of the joint becomes simple and contributes to the reduction of component costs and manufacturing costs.

These are the perspective views which show the structure of the paper feed cassette which concerns on one Embodiment of this invention. FIG. 4 is a perspective view of the sheet feeding cassette as viewed from the cassette cover side (in the direction of arrow B in FIG. 1). These are the enlarged views which looked at the display member vicinity of the paper feed cassette from the back surface direction of the cassette cover. FIG. 4 is an enlarged side view of the periphery of a movable lever showing a state where sheets are fully loaded in a sheet feeding cassette. FIG. 5 is an enlarged side view of the periphery of the movable lever showing a state in which the paper in the paper feed cassette is exhausted. These are the front views which looked at the engaging part of the display member and movable lever in FIG. 5 from the back surface direction of the cassette cover. FIG. 1 is a schematic cross-sectional view showing an overall configuration of a conventional image forming apparatus. These are sectional side views which show the structure of the conventional paper feed cassette.

Explanation of symbols

1 Image forming apparatus 10 Paper feed cassette (paper storage device)
25 Cassette base (housing)
28 Paper Loading Plate 28a Lever Press 34 Cassette Cover (Housing)
35 display member 35a display part 36 movable lever 36a support part 36b 1st arm part 36c 2nd arm part 38 bifurcated part 39 notch part d1, d2 play J engaging part

Claims (3)

A paper stacking plate provided so as to be able to be raised and lowered in accordance with a paper stacking amount; a movable lever provided to be swingable in conjunction with the raising and lowering of the paper stacking plate; and the movable lever engaged with the movable lever. And a display member that displays the remaining amount of paper by moving up and down in conjunction with the swing of
The paper storage device, wherein the movable lever and the display member engaging portion are configured such that the movable lever and the display member are sandwiched from each other in the vertical and horizontal directions.   The sheet storage device according to claim 1, wherein the engaging portion has a predetermined amount of play in the vertical and horizontal directions.   The movable lever is provided with a bifurcated portion composed of two ribs erected substantially in parallel, and the display member is provided with a notch portion having a substantially U-shaped cross section. The sheet storage device according to claim 1, wherein the bifurcated portion is engaged so as to be orthogonal to the notch portion.

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