Paper feed cassette

Abstract

To provide a paper feed cassette having a rotary plate capable of making a tip position of a sheet stable.SOLUTION: A paper feed cassette 10 is constituted by a paper storage part 11, a rotary plate 30 which is provided below the paper storage part 11 and lifts up paper stored in the paper storage part, and springs 29a, 29b lifting the rotary plate 30. The paper storage part 11 is provided with a vertical guide part 36 for guiding in the vertical movement of the rotary plate 30, and the rotary plate 30 has a guide member 38 sliding with the vertical guide part 36.SELECTED DRAWING: Figure 4B

Description

Technical Field

[0001] The present disclosure relates to a paper feed cassette.

Background Art

[0002] A paper feed cassette is provided with a rotating plate that is used to lift up the paper and press it against a pickup roller for conveyance. Conventionally, the rotation axis of the rotating plate is fixed, and it was common for the leading edge of the paper to retreat significantly after being lifted up compared to before. On the other hand, a paper feed cassette having a vertical guide portion that raises and lowers the paper feed side end of this rotating plate and no rotation axis provided at the opposite end is disclosed in, for example, Japanese Patent Application Laid-Open No. 2006-347662 (Patent Document 1). According to this publication, a pinion gear engages with the vertical guide portion, and a rack is provided on the vertical guide portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The rotating plate of the conventional paper feed cassette was configured as described above. In the rotating plate disclosed in Patent Document 1, although there is no rotation axis provided and the lift guide is vertical, the leading edge position of the paper cannot be brought to the foremost end of the rotating plate, so there was a problem that the leading edge position of the paper could not be stabilized before and after lifting.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a paper feed cassette having a rotating plate that can stabilize the leading edge position of the paper before and after lifting.

Means for Solving the Problems

[0006] The paper feed cassette according to the present disclosure includes a paper storage unit, a rotating plate provided below the paper storage unit for lifting the paper stored in the paper storage unit, an elastic member for lifting the downstream side of the rotating plate in the paper transport direction, and a support unit for supporting the upstream side of the rotating plate in the paper transport direction below the rotating plate. The paper feed cassette is provided with a vertical guide unit for guiding the rotating plate when the rotating plate moves up and down in the paper storage unit. The rotating plate projects the width of the vertical guide unit in a direction perpendicular to the paper transport direction of the rotating plate, and has guide members that slide with the vertical guide unit at the upstream end and the downstream end in the paper transport direction. The upstream end and the downstream end in the paper transport direction of the guide member that slide with the vertical guide unit are part of the side surface of a cylinder when a cylinder having the width of the vertical guide unit as the diameter is assumed.

[0007] Preferably, the rotating shaft located on the opposite side of the vertical guide unit is not fixed and is free.

[0008] The guide member may be formed of a material different from that of the rotating plate.

[0009] The guide member may have a thickness larger than the thickness of the rotating plate.

[0010] In a horizontal state where the rotating plate is not lifted up, it is preferable that the inclination between the straight line connecting the upper end of the upstream end of the guide member in the paper transport direction and the lower end of the downstream end of the guide member in the transport direction and the horizontal direction is greater than or equal to the maximum inclination that the rotating plate can take.

Advantages of the Invention

[0011] According to the present disclosure, there is a vertical guide unit for guiding a guide member that guides the rotating plate when the rotating plate is lifted up. Since the guide member slides with the vertical guide unit, the gap between the guide member and the vertical guide unit does not change before and after the lift-up.

[0012] As a result, it is possible to provide a paper feed cassette having a rotating plate that can stabilize the leading edge position of the paper before and after lift-up.

[0013] The above objects, other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description of the embodiments with reference to the drawings.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 3A

Figure 3B

Figure 3C

Figure 4A

Figure 4B

Embodiments for Carrying Out the Invention

[0015] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. FIG. 1 is a plan view showing a paper feed cassette according to an embodiment of the present disclosure. Referring to FIG. 1, a paper feed cassette 10 detachably attached to an image forming apparatus (not shown) includes a paper feed tray (paper storage section) 11 and an extension tray 20 drawn out as an extension portion with respect to the paper feed tray 11. Here, the extension tray 20 moves leftward in the drawing on an extension portion (guide plate 15, see FIG. 2A) of the paper feed tray 11.

[0016] The paper feed tray 11 has a bottom plate 12, left and right side plates 13a, 13b, and a back plate 14 connecting the left and right side plates 13a, 13b, and these parts are integrally formed of synthetic resin. The extension tray 20 has a bottom plate 21, left and right side plates 22a, 22b, and a standing wall portion 23 connecting the left and right side plates 22a, 22b, and these parts are integrally formed of synthetic resin. The left and right side plates 22a, 22b of the extension tray 20 are slidably inserted into the side plates 13a, 13b of the paper feed tray 11, and the bottom plate 21 is guided by the lower surface of the bottom plate 12 of the paper feed tray 11 and is slidable. A handle (not shown) is provided on the standing wall portion 23.

[0017] An operation portion (not shown) is provided near the paper feed tray 11 of the extension tray 20 and near one side plate 22b. By operating the operation portion, the extension tray 20 can be pulled out and deployed from the paper feed tray 11.

[0018] FIG. 2A is a plan view showing a state in which the extension tray 20 is deployed in FIG. 1, and is a view showing a state in which the extension tray 20 is deployed from the paper feed tray 11 by operating an operation portion (not shown). FIG. 2B is a side view of a portion indicated by arrow 2B-2B in FIG. 2A (a portion passing through the center of a spring 29a to be described later and extending in the drawing-out direction of the extension tray 20), FIG. 2C is a side view of a portion indicated by arrow 2C-2C in FIG. 2A, and FIG. 2D is a side view of a portion indicated by arrow 2D-2D in FIG. 2A (a portion passing through the centers of springs 29a and 29b to be described later).

[0019] Referring to FIGS. 2A to 2D, a guide plate 15 that enters below the bottom plate 21 of the extension tray 20 is provided on the bottom plate 12 of the paper feed tray 11, and the upper surface of this guide plate 15 guides the bottom plate 21 of the extension tray 20.

[0020] Also, in this embodiment, a pair of springs 29a and 29b that lift up the back plate 14 side are shown for the paper feed tray 11 having the extension tray 20 to feed paper (not shown) in the figure.

[0021] Next, a state in which the conveyance direction side end of the rotary plate 30 is lifted up with the extension tray 20 side end as a fulcrum will be described for the rotary plate 30 provided in the paper feed cassette 10 to convey paper (not shown) accommodated in the paper feed cassette 10 to an image forming unit (not shown). Here, first, a basic configuration for lifting up the right end of the rotary plate 30 will be described.

[0022] FIG. 3A is a side sectional view showing the whole rotary plate 30 provided in the paper feed cassette 10 shown in FIGS. 1 and 2A to 2D, FIG. 3B is an enlarged side sectional view of the vicinity of the extension tray side end of the rotary plate 30 shown by the rectangle 3B in FIG. 3A, FIG. 3C is an enlarged side sectional view of the conveyance direction side end of the rotary plate 30 shown by the rectangle 3C in FIG. 3A, and it is a figure showing a basic configuration for lifting up the conveyance direction side end of the rotary plate 30. Referring to FIGS. 3A to 3C, a case where the rotary plate 30 is attached to the paper feed tray 11 in a state where the extension tray 20 shown in FIG. 2B is extended will be described. Here, the cross-sectional position of the cross-sectional views shown in FIGS. 3A to 3C is the same as that shown in FIG. 2B, and it is a portion passing through the center of the spring 29a and extending in the pulling-out direction of the extension tray 20. Note that in FIGS. 1, 2A to 2D, the illustration of the rotary plate is omitted.

[0023] In the basic configuration as shown in Fig. 3A, the end of the rotary plate 30 on the extension tray side serves as the fulcrum of rotation, and the end of the rotary plate 30 on the conveyance direction side is lifted up by the biasing force of the spring 29a to a predetermined paper feeding position while the displacement range of the guide member 37a along the vertical guide portion 36 is restricted as indicated by the arrow in the figure. In the figure, a state where the paper cassette 10 is almost full of paper (in the figure, the rotary plate 30 is in a horizontal state) and a state where there is no paper in the paper cassette 10 (in the figure, the rotary plate 30 is lifted at the end on the conveyance direction side) are shown.

[0024] The paper cassette 10 lifts up the rotary plate 30 as the paper is supplied one by one to the main body from a state where the paper cassette 10 is almost full of paper, and the amount of paper in the paper cassette 10 decreases. When the rotary plate 30 is lifted up, the guide member 37a moves along the vertical guide portion 36 while the rotary plate 30 is displaced until there is no paper in the paper cassette 10.

[0025] Note that the guide member when the rotary plate 30 is horizontal is denoted as 37b, and the guide member during lift-up is denoted as 37a.

[0026] Fig. 3A also shows the rotary shaft 33 conventionally provided at the end of the rotary plate 30 on the extension tray side and a paper guide 32 for guiding the side surface of the paper (not shown).

[0027] Referring to Fig. 3B, a hemispherical convex portion 34 is provided near the end of the rotary plate 30 on the extension tray side, and a self-weight contact portion that contacts the hemispherical convex portion 34 is provided on the back surface near the end of the rotary plate 30 on the extension tray side at the portion surrounded by the dotted circle ○. Fig. 3B also shows the rotary shaft 33 conventionally provided for reference. In Fig. 3A, the hemispherical convex portion 34 is provided so as to protrude upward from the bottom plate 12, but it may be provided so as to protrude downward from the back surface of the rotary plate 30.

[0028] [First Embodiment] In the present disclosure, without using the conventionally provided rotating shaft, a hemispherical convex portion 34 that abuts against the back surface near the end portion on the extension tray side of the rotating plate 30 is provided on the bottom plate 12 of the paper feed tray, and the rotating shaft disposed on the opposite side of the vertical guide portion 36 is not fixed and is configured to be free. By configuring it to be free in this way, on the one hand, it guides so that the tip position of the rotating plate 30 becomes constant by the guide member 37 and the vertical guide portion 36, and on the other hand, because the inclination of the rotating plate 30 is larger, the end portion on the extension tray side is displaced in the horizontal direction.

[0029] Next, the end portion on the conveyance direction side where the rotating plate 30 is lifted up will be described. Referring to FIG. 3C, there are a vertically extending spring 29a that lifts the end portion on the conveyance direction side of the rotating plate (not shown), a vertical guide portion 36 provided in the paper feed cassette 10 that guides the guide member 37, a guide member 37a of the rotating plate (not shown) that is attached to the end portion on the conveyance direction side of the rotating plate (not shown) guided by the vertical guide portion 36 and is lifted up, and a guide member 37b of the rotating plate (not shown) when the rotating plate (not shown) is in a horizontal state.

[0030] The guide member 37 is a separate member such as resin provided so as to project in a direction orthogonal to the conveyance direction on the end portion side in the conveyance direction of the rotating plate. Note that the rotating plate may be made of sheet metal or may be formed of resin, and the rotating plate 30 and the guide member 37 may be integrally formed or may be formed of a separate member with high slidability.

[0031] Here, the portions of the guide members 37a and 37b that contact the vertical guide portion 36 are each semi-circular in shape with different central positions when viewed from the side of the paper feed cassette, are flat when viewed from the upper part of the paper feed cassette, and have short protrusions downward from the circular central portion. As shown in FIG. 3C, when the rotating plate 30 is substantially horizontal, the guide member 37b is also substantially horizontal and there is almost no gap with the guide groove. On the other hand, when the rotating plate (not shown) is lifted up, since the rotating plate (not shown) is inclined obliquely, The guide member 37 also becomes inclined, assuming the state of the guide member 37a. As shown by the dotted circle in the figure, a large gap is created between the vertical guide portion 36 and the guide member 37a, and the leading edge position of the paper (not shown) becomes unstable. Also, since this gap does not restrict the vibration of the rotating plate, it also becomes a factor of noise during paper feeding.

[0032] Incidentally, as shown in FIG. 3C, the shape of the vertical guide portion 36 provided on the back plate 14 of the paper feed tray 11 is a vertical slit shape. This shape is adopted because it is easy to manage the dimensions.

[0033] Next, the lift-up configuration of the rotating plate 30 according to the present disclosure will be described with respect to the basic lift-up configuration of the rotating plate 30 shown in FIGS. 3A to 3C. FIG. 4A is a side view showing the vertical guide portion 36 on the paper feed cassette 10 side and the guide members 38a and 38b provided at the transport direction side end of the rotating plate (not shown) guided by the vertical guide portion 36, and FIG. 4B is a side view showing the shapes of the guide members 38a and 38b at the upper and lower guide positions of the rotating plate (not shown).

[0034] Referring to FIG. 4A, the guide member 38a in the lifted-up rotating plate (not shown) has almost no gap between the vertical guide portion 36 and the guide member 38a when the transport direction side end of the rotating plate (not shown) is lifted up, as shown by the dotted circle in FIG. 4A. This is the same when the guide member 38b is located at the lower end of the vertical guide portion 36 when the rotating plate (not shown) is horizontal. In this way, since the gap between the vertical guide portion 36 and the guide members 38a and 38b does not change before and after lift-up, the leading edge position of the paper (not shown) becomes stable.

[0035] Incidentally, the positions of the spring 29a and the vertical guide portion 36 shown in FIG. 4A in the paper feed cassette 10 are also shown in FIG. 2B.

[0036] [Second Embodiment] Next, the specific shape of the guide member 38 according to the present disclosure will be described. Referring to FIG. 4B, according to the present disclosure, the end shapes of the guide members 38a and 38b in contact with the vertical guide portion 36 are not partial shapes of semi-circles with different centers as described in FIG. 3C for both the upstream end and the downstream end in the paper passing direction. Instead, as shown by the large circle in FIG. 4B, it is a part of the side surface of a cylinder having the width of the vertical guide portion 36 as the diameter when viewed from the side. By adopting such a configuration, the gap between the vertical guide portion 36 and the guide members 38a and 38b is the same both before and after the lift-up of the rotating plate 30. In this way, regardless of the degree of inclination due to the lift-up of the rotating plate 30, the gap between the vertical guide portion 36 and the guide member 38 slides in the vertical direction while being kept constant.

[0037] More specifically, in FIG. 4B, both the guide member 38a at the inclined position shown above and the guide member 38b at the horizontal position shown below are, when the shape of the sliding portion with the vertical guide portion 36 is assumed to be a cylinder having the width of the vertical guide portion 36 as the diameter, a part of the side surface of that cylinder. As a result, when the guide member 38a is inclined, a part above the end portion on the extension tray side of the guide member 38a and a part below the end portion on the conveyance direction side of the guide member 38a are slidably in contact with the perpendicular vertical guide portion 36, respectively. Further, when the guide member 38b is horizontal, a part near the vertical center of the end portion on the extension tray side of the guide member 38b and a part near the vertical center of the end portion on the conveyance direction side of the guide member 38b are slidably in contact with the vertical guide 36. That is, the guide member 38 needs to maintain contact with the vertical guide portion 36 within the range of inclination in which the rotating plate 30 can move. That is, the straight line connecting the contact portion of the end portion on the extension tray side of the guide member 38a with the vertical guide portion 36 and the contact portion of the end portion on the conveyance direction side of the guide member 38a with the vertical guide portion 36 is parallel to the horizontal direction, and the inclination of the straight line connecting the upper end portion of the end portion on the extension tray side of the guide member 38b and the lower end portion of the end portion on the conveyance direction side of the guide member 38b with respect to the horizontal direction is greater than the maximum inclination that the rotating plate 30 can take.

[0038] In the above-described embodiment, the rotating plate in the state where the extension tray is deployed has been described. However, since the rotating plate is provided on the paper feed tray, it is not affected by whether the extension tray is deployed or stored. That is, the same applies when the extension tray is stored. Note that the hemispherical convex portion 34 that abuts on the rotating plate and the free rotation shaft may be provided on the extension tray. In that case, the rotating plate can be expanded and contracted in accordance with the expansion and contraction of the extension tray.

[0039] The present disclosure can be implemented in various other forms without departing from its spirit or main features. Therefore, the above-described embodiments are merely illustrative and should not be construed in a limiting sense. Modifications and changes belonging to the equivalent scope of the claims of the present disclosure are all within the scope of the present disclosure.

Industrial Applicability

[0040] According to the present disclosure, it is possible to provide a paper feed cassette having a rotating plate capable of stabilizing the leading edge position of the paper before and after lifting, and thus it is useful as a paper feed cassette.

Explanation of Signs

[0041] 10 Paper feed cassette 11 Paper feed tray (paper storage section) 12 Bottom plate 13a, 13b Side plates 14 Rear plate 15 Guide plate 20 Extension tray 21 Bottom plate 22a, 22b Side plates 23 Standing wall portion 26 Lock operation portion 29a, 29b Springs (elastic members) 30 Rotating plate 32 Paper guide 33 Rotation shaft 34 Hemispherical convex portion 36 Vertical guide portion 37 Guide member (basic configuration) 38 Guide member (present disclosure)

Claims

1. A paper storage section, a rotary plate provided below the paper storage section for lifting up the paper stored in the paper storage section, an elastic member for lifting the downstream side in the paper conveyance direction of the rotary plate, a support section for supporting the upstream side in the paper conveyance direction of the rotary plate below the rotary plate, which is a paper feed cassette composed of: a vertical guide section for guiding the rotary plate during its vertical movement is provided in the paper storage section, and the rotary plate projects the width of the vertical guide section in a direction orthogonal to the paper conveyance direction of the rotary plate, and has guide members whose upstream end and downstream end in the paper conveyance direction slide on the vertical guide section, The upstream end and downstream end in the paper conveyance direction of the guide member that slide on the vertical guide section are part of the side surface of a cylinder when a cylinder with the width of the vertical guide section as the diameter is assumed, the paper feed cassette.

2. The paper feed cassette according to claim 1, wherein the rotating shaft located on the opposite side of the vertical guide section is not fixed and is free.

3. The paper feed cassette according to claim 1, wherein the guide member is formed of a material different from that of the rotary plate.

4. The paper feed cassette according to claim 1, wherein the guide member has a thickness larger than the thickness of the rotary plate.

5. The paper feed cassette according to claim 1, wherein in a horizontal state where the rotary plate is not lifted up, the inclination between the straight line connecting the upper end of the upstream end in the paper conveyance direction of the guide member and the lower end of the downstream end in the conveyance direction of the guide member and the horizontal direction is equal to or greater than the maximum inclination that the rotary plate can take.

Images