JP4877968B2 - Paper supply device - Google Patents

Description

  The present invention relates to a paper supply device such as a cut paper, which can be applied to an image forming apparatus represented by a copying machine or a printer.

  The paper supply device is indispensable for feeding cut paper or the like in an image forming apparatus represented by a copying machine or a printer. In a paper supply device in an image forming apparatus, a large number of sheets before printing are stored in advance in a paper storage unit such as a paper feed cassette or a paper feed tray, and one sheet is stacked from the top layer of the paper stacked in the paper storage unit. Many papers are supplied separately. Such a paper supply device is used for a cassette type paper feeding unit, a manual paper feeding unit, a document feeding unit, and the like of an image forming apparatus.

  There are a roller supply method and a suction supply method as a method of feeding paper from the paper supply device to the outside, and the roller supply method is generally widely used. In the roller supply method, a pickup roller presses against the uppermost layer of the sheet bundle, delivers the sheet to a sheet feeding roller on the downstream side in the sheet feeding direction, and feeds the sheet to the outside of the sheet feeding apparatus. As a method of pressing the uppermost layer of the sheet bundle against the pickup roller, a method of lifting the lift plate on which the sheets are stacked from below by a driving device equipped with a motor or the like and a method of lifting by a biasing means such as a spring And exist.

  Here, in a paper supply device equipped with a paper cassette that can be pulled out from the device main body, when the paper cassette is pulled out or stored from the device main body, the upper part of the paper bundle contacts the frame above the paper cassette. Therefore, it is desirable to lower the lift plate in order to avoid damage. Furthermore, when the paper is replenished inside the paper cassette after the paper cassette is pulled out, it is desirable to hold the lift plate near the bottom surface of the paper cassette in consideration of replenishment workability.

When the sheet feeding cassette is pulled out and stored, the operation and holding of the lift plate can be easily realized when the drive device is used to change the posture of the lift plate. However, when a biasing means such as a spring is used to change the posture of the lift plate, devise to realize the operation and holding of the lift plate when pulling out and storing the paper feed cassette as described above. A sophisticated mechanism design is required. An example of such a paper supply device can be seen in Japanese Patent Application Laid-Open No. 2005-228561. In the sheet supply device (paper supply device) described in Patent Document 1, the bottom plate (lift plate) is pushed down by a latch member when the paper feed cassette is pulled out from the apparatus main body.
Japanese Patent Laid-Open No. 2001-2251 (page 7, FIG. 7)

  Since the sheet supply device (paper supply device) described in Patent Document 1 is provided with a latch member, the bottom plate (lift plate) can be pushed down when the paper feed cassette is pulled out from the apparatus main body. It is possible to avoid damage to the upper part of the sheet bundle when the sheet cassette is pulled out and stored. Furthermore, the sheet supply device described in Patent Document 1 operates in response to the vertical movement of the bottom plate (lift plate), thereby displaying the remaining amount of paper stored in the paper feed cassette. Display means (paper remaining amount display mechanism) is also provided. However, in such a configuration, the latch member that is a member that pushes down the bottom plate (lift plate) is a member that is independent from the member that constitutes the remaining amount display means (paper remaining amount display mechanism), and the latch member. And the remaining amount display means (paper remaining amount display mechanism) are arranged at a distance from each other. As a result, the number of parts constituting the paper supply device is greatly increased, and a space for constituting these mechanisms must be secured separately. Therefore, there arises a problem that the paper supply device is increased in cost and size.

  The present invention has been made in view of the above points, and includes a paper feed cassette that can be pulled out from the apparatus main body, and a lift plate that is disposed in the paper feed cassette and on which the paper is placed on the upper surface. By reducing the number of parts and saving space with a simple mechanism in the supply device, it is possible to reduce costs and size, and to push down the lift plate when pulling out the paper cassette and to reduce the remaining amount of paper. An object of the present invention is to provide a paper supply device capable of reliably performing display.

  In order to solve the above-described problems, the present invention provides a paper feed cassette that can stack and store paper and can be pulled out from the apparatus body, and a lift that is disposed in the paper feed cassette and on which the paper is placed on the upper surface. In a paper supply device equipped with a plate, a push-down mechanism that pushes down the lift plate to the vicinity of the bottom surface of the paper cassette when the paper cassette is pulled out from the device main body, and the remaining amount of paper placed on the lift plate is displayed. A link member comprising a pressing member that engages with and lifts the lift plate, and a variable member that displaces the indicating piece that indicates the remaining amount of paper. I decided to prepare.

  Further, in the paper supply apparatus having the above-described configuration, the link member engages with the lift plate at one end, engages with the indicating piece at the other end, and a support shaft portion at a substantially central portion between these end portions. It was decided to make a seesaw shape.

  In the paper supply apparatus having the above-described configuration, a lock mechanism that locks the lift plate in the vicinity of the bottom surface of the paper feed cassette is provided, and the lock mechanism locks the lift plate by engaging with the link member. did.

  Further, the paper supply device having the above-described configuration includes a lock release mechanism that releases the lock of the lift plate by releasing the engagement between the link member and the lock mechanism when the paper cassette is stored in the apparatus main body. It was.

  According to the configuration of the present invention, it is provided with a paper feed cassette that can stack and store paper and can be pulled out from the apparatus main body, and a lift plate that is disposed in the paper feed cassette and on which the paper is placed on the upper surface. In the paper supply device, when the paper cassette is pulled out from the device body, a push-down mechanism that pushes down the lift plate to the vicinity of the bottom surface of the paper feed cassette, and a paper remaining amount display mechanism that displays the remaining amount of paper placed on the lift plate And a pressing member that engages with the lift plate and pushes it down, and a variable member that displaces the indicating piece that indicates the remaining amount of paper are provided with an integrally formed link member. The push-down member for the lift plate and the variable member for displacing the indicator piece can be configured as a single member. Further, the lift plate push-down mechanism and the remaining paper amount display mechanism can be brought close to each other to be compactly accommodated. As a result, the number of parts can be reduced and the space can be saved with a simple mechanism, and the cost and size of the paper supply device can be reduced. In addition, it is possible to provide a paper supply device that can reliably perform the push-down of the lift plate and the display of the remaining amount of paper when the paper cassette is pulled out.

  In addition, the link member is engaged with the lift plate at one end, and is engaged with the indicating piece at the other end, so that a seesaw shape having a support shaft portion at a substantially central portion between these ends is formed. It is possible to configure the lift plate push-down mechanism and the remaining sheet amount display mechanism with simple mechanisms, and it is possible to reduce the size of these mechanisms. Thus, the lift plate push-down mechanism and the remaining sheet amount display mechanism can be compactly accommodated in the sheet feeding cassette. Accordingly, it is possible to further improve the downsizing and cost reduction of the paper supply device.

  In addition, a lock mechanism for locking the lift plate near the inner bottom surface of the paper feed cassette is provided, and this lock mechanism locks the lift plate by engaging with the link member. There is no need to separately provide a member necessary for locking. Accordingly, the number of parts is reduced, and the downsizing and cost reduction of the lift plate pressing mechanism can be further enhanced.

  In addition, when the paper cassette is stored in the device body, the lock release mechanism is released to release the lock of the lift plate by releasing the engagement between the link member and the lock mechanism. The pickup roller can be pressed against the uppermost layer of the sheet bundle. As a result, a simple mechanism using a link member can reliably push down the lift plate when the paper cassette is pulled out, and easily urge the lift plate upward when the paper cassette is stored. Is possible.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. Here, it is assumed that the paper supply apparatus of the present invention is designed to be disposed below an image forming apparatus (printer) as a device.

  First, an outline of the structure of a paper supply apparatus according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a right side view of a vertical section of a paper supply device, FIG. 2 is a partial perspective view of a front portion of the paper supply device, as viewed from the front, and FIG. 3 is a perspective view of a link member provided in the front portion of the paper supply device. . In FIG. 1, the left side indicates the front side of the paper supply apparatus, and the right side indicates the back side.

  As shown in FIG. 1, the paper supply device 1 is provided in a lower portion of a printer 100 that is a device. The paper supply device 1 is provided with a paper feed cassette 2. As shown in FIG. 2, a guide rail 3 extending in the front-rear direction of the printer 100 is provided on the side surface of the paper feed cassette 2. By engaging a not-shown horizontal projection (not shown) provided inside the paper supply device 1 inside the guide rail 3, the paper feed cassette 2 is placed horizontally with respect to the main body of the printer 100, that is, in the left-right direction in FIG. It is possible to pull it out.

  As shown in FIG. 1, the paper feed cassette 2 is constituted by a flat box whose upper surface is open, and a front panel 4 is provided on the front surface thereof. The front panel 4 plays a role of constituting a part of a housing at the lower front of the printer 100. The sheets P are stacked and accommodated from the upper surface of the sheet cassette 2 and are moved from the right to the left by the sheet feeder 5 provided at the upper front of the sheet cassette 2, that is, the upper left side in FIG. Sent out.

  A lift plate 6 is provided inside the paper feed cassette 2. The paper P is placed on the upper surface of the lift plate 6. The lift plate 6 is supported at its upstream end in the sheet feeding direction, that is, the right end in FIG. 1, on both side walls in the sheet width direction of the sheet feeding cassette 2 perpendicular to the sheet feeding direction. The lift plate 6 can rotate in a vertical plane with the support portion as the center and the downstream end as a free end.

  A spring 7 is provided below the lift plate 6 on the downstream side in the sheet feeding direction between the lift plate 6 and the inner bottom surface of the sheet feeding cassette 2. The spring 7 is a biasing means that biases the downstream portion of the lift plate 6 to displace upward. The lift plate 6 is lifted upward by the action of the spring 7, and the uppermost layer of the sheet bundle is in contact with the pickup roller 5 a of the paper feed device 5 provided above the downstream portion of the paper supply device 1. Displace to supply position. The sheets P on the lift plate 6 are separated one by one by the sheet feeding device 5 and sent out to the outside of the sheet feeding device 1, that is, toward the upper left side in FIG.

  As shown in FIG. 2, a push-down mechanism 10 for the lift plate 6 and a remaining paper amount display mechanism 20 are provided on the right side of the sheet feeding cassette 2 as viewed from the front and in the vicinity of the front. ing. The push-down mechanism 10 is provided near the downstream end of the lift plate 6, and the remaining paper amount display mechanism 20 is provided immediately behind the front panel 4. A link member 8 extending in the front-rear direction is disposed so as to straddle between the push-down mechanism 10 and the remaining paper amount display mechanism 20. The link member 8 is provided inside the side wall of the paper feed cassette 2.

  The link member 8 plays an important role in the operation of the push-down mechanism 10 of the lift plate 6 on the upstream side in the paper feeding direction, that is, in the vicinity of the rear side, and on the downstream side in the paper feeding direction, that is, near the end on the front side. It is a member that plays an important role related to the operation of the remaining paper amount display mechanism 20. As shown in FIG. 3, the link member 8 has a support shaft portion 8a at a substantially central portion between these end portions, and has a seesaw shape that swings in a vertical plane about an axis center extending substantially horizontally in the paper width direction. There is no.

  Next, the detailed configuration and operation of the push-down mechanism 10 of the lift plate 6 and the remaining paper amount display mechanism 20 will be described with reference to FIGS. 4 to 15 in addition to FIGS. .

  First, the configuration of the push-down mechanism 10 for the lift plate 6 will be described with reference to FIGS. 4 to 6 in addition to FIGS. 2 and 3. 4 is a partial perspective view of the front portion of the paper supply device, as viewed from the rear, FIG. 5 is a partial perspective view showing an engagement position with a link member inside the paper supply device, and FIG. 6 is a vertical sectional rear view around the lock mechanism. It is. In FIG. 5, drawing is performed in such a manner that only the link member 8 provided in the sheet feeding cassette 2 is arranged on the inner side surface of the sheet feeding device 1, and drawing of the sheet feeding cassette 2 itself is omitted.

  As shown in FIGS. 2 to 5, the push-down mechanism 10 for the lift plate 6 is provided near the downstream end of the lift plate 6, and includes a lift plate engaging portion 11, a push-down guide engaging portion 12, and a push-down guide member 13. And.

  As shown in FIG. 3, the lift plate engaging portion 11 is provided on the upstream side of the link member 8 in the sheet feeding direction, that is, on the end on the rear side. As shown in FIG. 5, the lift plate engaging portion 11 is provided with two plate-like protrusions 11 a extending toward the inside of the paper feed cassette 2. As shown in FIGS. 2 and 4, the lift plate 6 is disposed between the two plate-like protrusions 11 a. As a result, the link member 8 rotates about the support shaft portion 8a, and when the lift plate engaging portion 11 moves up and down with this, the downstream end of the lift plate 6 is caught by the two plate-like protrusions 11a. The edge is displaced vertically. Alternatively, the lift plate engaging portion 11 is displaced in the vertical direction as the downstream end of the lift plate 6 moves up and down, and the link member 8 rotates about the support shaft portion 8a.

  As shown in FIG. 3, the push-down guide engaging portion 12 is provided at a position slightly ahead of the lift plate engaging portion 11 of the link member 8 and near the support shaft portion 8 a. The push-down guide engaging portion 12 is provided with an engaging pin 12a extending toward the outside of the paper feed cassette 2. The engaging pin 12a is provided on the side wall of the paper feed cassette 2, and protrudes toward the outside of the paper feed cassette 2 through an opening 9 extending in the vertical direction.

  As shown in FIG. 5, the push-down guide member 13 is provided on the outer side in the paper width direction of the paper feed cassette 2 and on a substantially vertical side surface inside the paper supply device 1. The push-down guide member 13 is provided with a rear guide portion 13a that is inclined downward from the rear to the front of the paper supply device 1, and a front guide portion 13b that is inclined downward from the front to the rear. . The push-down guide member 13 is disposed at a position corresponding to the engagement pin 12a of the push-down guide engagement portion 12. The rear guide portion 13a and the front guide portion 13b are engagement pins when the paper feed cassette 2 is pulled out and stored. 12a is engaged and engaged.

  A lock mechanism 30 for the lift plate 6 is provided below the push-down mechanism 10 for the lift plate 6 having such a configuration, as shown in FIG. The lock mechanism 30 is disposed below the portion corresponding to the lift plate engaging portion 11 of the push-down mechanism 10 and on the link member 8 and the inner bottom surface of the paper feed cassette 2. As shown in FIGS. 4 to 6, the lock mechanism 30 includes a lock piece 31, a guide groove 32, a spring 33, and a lock piece engaging portion 34.

  The lock piece 31 is a plate-like member extending substantially in the horizontal direction, and is provided so as to be movable only in the horizontal direction in the paper width direction along the guide groove 32 shown in FIG. The guide groove 32 is a groove provided on the inner bottom surface of the paper feed cassette 2 and extending substantially horizontally in the paper width direction. A through hole 31 a that penetrates in the vertical direction is provided at the center of the lock piece 31. Further, as shown in FIG. 6, the lock piece 31 has an outer end 31 b protruding from the side wall of the paper feed cassette 2 to the outside.

  The spring 33 is arranged between the wall portion extending upward from the inner bottom surface of the sheet feeding cassette 2 and the lock piece 31 so that the axis is substantially horizontal. The spring 33 urges the lock piece 31 substantially horizontally toward the outside of the paper feed cassette 2. Note that the lock piece 31 does not jump out of the sheet feeding cassette 2 beyond the position shown in FIGS. 2, 4, and 6 due to the action of a stopper (not shown).

  As shown in FIG. 5, the lock piece engaging portion 34 is provided on the upstream side in the sheet feeding direction of the link member 8, that is, on the rear side, and below the lift plate engaging portion 11. Similar to the lift plate engaging portion 11, the lock piece engaging portion 34 is provided with a single plate-like protrusion 34 a extending toward the inside of the paper feed cassette 2. The lock piece 31 is positioned below the lock piece engaging portion 34, and the through hole 31 a of the lock piece 31 is sized to receive the plate-like protrusion 34 a of the lock piece engaging portion 34.

  Further, as shown in FIG. 5, a lock release mechanism 40 is provided for such a lock mechanism 30. The lock release mechanism 40 is provided on the outer side of the paper feed cassette 2 and on a substantially vertical side surface inside the paper supply device 1. The lock release mechanism 40 includes a lock release protrusion 41.

  The unlocking protrusion 41 is provided below the push-down guide member 13 of the push-down mechanism 10. The unlocking protrusion 41 is configured to protrude toward the paper feed cassette 2 at a height corresponding to the lock piece 31 of the lock mechanism 30.

  Next, operations of the push-down mechanism 10, the lock mechanism 30, and the lock release mechanism 40 of the lift plate 6 will be described with reference to FIGS. 7 is a side view showing the position of the push-down mechanism of the lift plate, showing the state where the lift plate is located on the upper side, and FIG. 8 is a side view showing the position of the push-down mechanism similar to FIG. 9 is a lower side view, FIG. 9 is a vertical cross-sectional rear view around the locking mechanism similar to FIG. 6, and shows a state immediately before locking, FIG. 10 is a locking mechanism periphery similar to FIG. FIG. 11 is a vertical sectional rear view of the periphery of the locking mechanism similar to FIG. 10 and shows the unlocked state.

  7 and 8 are views of the position of the push-down mechanism 10 for the lift plate 6 as viewed from the inside of the paper feed cassette 2, and drawing of frames such as the side walls of the paper feed cassette 2 is omitted. . 7 and 8, the right side shows the front side of the sheet feeding apparatus 1, and the left side shows the back side. That is, the paper feed cassette 2 is pulled out to the right in FIGS.

  FIG. 7 shows a state in which the paper P placed on the lift plate 6 has almost disappeared. The lift plate 6 is urged upward by the action of a spring 7 (see FIG. 1) provided between the lift plate 6 and the inner bottom surface of the paper feed cassette 2 below the paper feed direction downstream portion. It has been. The lift plate 6 is engaged with the lift plate engaging portion 11 of the push-down mechanism 10 at this location, and lifts the plate-like protrusion 11a on the upper side. Therefore, the link member 8 is rotated in the clockwise direction in FIG. 7 around the support shaft portion 8a.

  When the paper feeding cassette 2 is pulled out from the printer 100 main body from this state, the engaging pin 12 a of the push-down guide engaging portion 12 of the push-down mechanism 10 comes into contact with the rear guide portion 13 a of the push-down guide member 13. When the sheet feeding cassette 2 is further pulled out, the engaging pin 12a is caught by the rear guide portion 13a, and the link member 8 is rotated counterclockwise in FIG. Thereby, the lift plate 6 is pushed down against the spring 7 (see FIG. 1) by the plate-like protrusion 11a on the upper side of the lift plate engaging portion 11.

  When the paper cassette 2 is further pulled out, the link member 8 is rotated, and the lift plate 6 is pushed down to the vicinity of the inner bottom surface (not shown) of the paper cassette 2 as shown in FIG.

  FIG. 9 shows the position of the lock mechanism 30 immediately before the lift plate 6 is pushed down to the lowest position. The lock piece engaging portion 34 of the lock mechanism 30 reaches the position of the through hole 31 a of the lock piece 31. Here, the lower end of the plate-like protrusion 34a of the lock piece engaging portion 34 contacts the upper portion of the through hole 31a of the lock piece 31, and the lock piece 31 is guided by the guide groove 32 (FIG. 4), the sheet is moved toward the inside of the sheet feeding cassette 2 against the spring 33. And the lock piece engaging part 34 is gradually inserted in the through-hole 31a.

  Further, when the lift plate 6 is pushed down to the lowest position and the plate-like protrusion 34a of the lock piece engaging portion 34 passes through the through hole 31a and reaches the lower side of the lock piece 31, as shown in FIG. As a result, the lock piece 31 is pushed toward the outside of the paper feed cassette 2. As a result, the lock mechanism 30 is engaged with the link member 8 and the lock of the lift plate 6 near the inner bottom surface of the paper feed cassette 2 is completed.

  On the other hand, when the paper feed cassette 2 is stored in the printer 100 main body, as shown in FIG. 11, the unlocking projection 41 of the unlocking mechanism 40 has the end of the lock piece 31 protruding outward from the side wall of the paper feed cassette 2. It contacts the part 31b. As a result, the lock piece 31 is pushed inward of the paper feed cassette 2, and the engagement between the lock piece 31 and the lock piece engaging portion 34 is released. As a result, the lift plate 6 is urged upward by the action of a spring 7 (see FIG. 1) provided between the inner bottom surface of the paper feed cassette 2 and lifted. When the sheet P is placed on the upper surface of the lift plate 6, the uppermost layer of the sheet bundle is in contact with the pickup roller 5 a of the sheet feeding device 5 provided above the downstream portion of the sheet feeding device 1. Displace to position.

  Next, the configuration of the remaining paper amount display mechanism 20 will be described with reference to FIGS. 12 and 13 in addition to FIGS. FIG. 12 is a perspective view of the indicating piece, and FIG. 13 is a perspective view showing an engaged state between the indicating piece and the link member.

  As shown in FIGS. 2, 3, 12, and 13, the remaining paper amount display mechanism 20 is provided immediately behind the front panel 4, and includes an indication piece engaging portion 21, an indication piece 22, and a display portion 23. And.

  As shown in FIG. 3, the pointing piece engaging portion 21 is provided on the downstream side of the link member 8 in the sheet feeding direction, that is, on the front end. The indicating piece engaging portion 21 is provided with an engaging pin 21 a extending toward the inside of the sheet feeding cassette 2. The link member 8 is engaged with the indicating piece 22 by the engaging pin 21a of the indicating piece engaging portion 21 (see FIG. 13).

  As shown in FIG. 2, the indication piece 22 is disposed immediately behind the front panel 4. As shown in FIG. 12, the instruction piece 22 is configured by a block whose outer shape is substantially a rectangular parallelepiped shape, and is provided with an instruction portion 22 a that indicates the remaining amount of paper on the front surface thereof. The instructing unit 22a clearly indicates the remaining amount of paper by engraving the scale or applying a coating different from the surroundings.

  As shown in FIGS. 12 and 13, a guide portion 22 b is provided at the lower portion of the instruction piece 22. The guide portion 22b is configured in the form of a recess extending in the front-rear direction of the indication piece 22. The guide portion 22b is a portion that receives the engaging pin 21a of the indicating piece engaging portion 21, and has a size that allows the engaging pin 21a to move smoothly forward and backward.

  Further, as described above, the instruction piece 22 is disposed immediately behind the front panel 4 and is engaged with a guide rail (not shown) extending in the vertical direction. With this guide rail, the indication piece 22 can move smoothly only in the vertical direction.

  The display unit 23 is provided at a location on the front panel 4 corresponding to the instruction unit 22 a of the instruction piece 22. The display unit 23 is configured by a window having an opening shape. An indication piece 22 is disposed immediately behind the front panel 4 at the position of the display unit 23, and the displacement of the indication piece 22, that is, the remaining amount of paper can be confirmed from the front of the paper supply apparatus 1 through the display unit 23. .

  Next, the operation of the remaining paper amount display mechanism 20 as described above will be described with reference to FIGS. FIG. 14 is a right side view showing the remaining paper amount display mechanism, showing a state where the lift plate is positioned on the lower side, and FIG. 15 is a right side view showing the remaining paper amount display mechanism similar to FIG. It shows a state where the lift plate is located on the upper side.

  14 and 15 are views of the remaining paper amount display mechanism 20 as viewed from the outside of the paper feed cassette 2, and drawing of frames such as the side walls of the paper feed cassette 2 is omitted. 14 and 15, the left side indicates the front side of the sheet supply apparatus 1, and the right side indicates the back side.

  FIG. 14 shows a state in which the paper P is almost fully loaded in the paper feed cassette 2 (the paper P is not shown in FIG. 14). The lift plate 6 descends to the vicinity of the inner bottom surface of the paper feed cassette 2 due to the weight of the paper bundle. The lift plate 6 is engaged with the lift plate engaging portion 11 of the push-down mechanism 10 at this location, and pushes down the lower plate-like protrusion 11a. Accordingly, the link member 8 is rotated in the clockwise direction in FIG. 14 around the support shaft portion 8a.

  Thereby, the location of the indicator piece engaging part 21 provided in the downstream part of the link member 8, ie, the edge part of the front side, raises. Therefore, the indication piece 22 engaged with the engagement pin 21a of the indication piece engaging portion 21 also rises along a guide rail (not shown) extending in the vertical direction. When the display unit 23 is viewed from the front, the instruction unit 22a of the instruction piece 22 instructs the full state of the paper P.

  As the number of sheets P in the sheet cassette 2 decreases, the downstream end of the lift plate 6 is lifted by the action of a spring 7 (see FIG. 1) provided therebelow. Then, the lift plate 6 lifts the lift plate engaging portion 11 engaged at this location, and the link member 8 gradually rotates counterclockwise in FIG.

  Thereby, the location of the indicating piece engaging portion 21 of the link member 8 is lowered. As a result, the indication piece 22 that engages with the engagement pin 21a of the indication piece engaging portion 21 also descends along the guide rail due to the action of gravity.

  In this way, FIG. 15 depicts a state in which the paper P in the paper feed cassette 2 has almost disappeared. When the display unit 23 is viewed from the front, the instruction unit 22a of the instruction piece 22 indicates that the paper P has been emptied.

  As described above, the paper P is stacked and stored, and can be pulled out from the main body of the printer 100, which is a device. The paper cassette 2 is disposed in the paper cassette 2, and the paper P is placed on the upper surface. In the paper supply device 1 including the lift plate 6, the push-down mechanism 10 that pushes down the lift plate 6 to the vicinity of the inner bottom surface of the paper feed cassette 2 when the paper feed cassette 2 is pulled out from the main body of the printer 100, and the lift plate 6. A sheet remaining amount display mechanism 20 that displays the remaining amount of the sheet P, a push-down member that engages with the lift plate 6 and pushes it down, and a variable member that displaces the indication piece 22 that indicates the remaining sheet amount. However, since the link member 8 formed integrally is provided, the push-down member of the lift plate 6 and the variable member for displacing the indicating piece 22 can be configured as a single member. . In addition, the push-down mechanism 10 of the lift plate 6 and the remaining paper amount display mechanism 20 can be brought close to each other and can be stored compactly. As a result, the number of parts can be reduced and the space can be saved with a simple mechanism, and the paper supply device 1 can be reduced in cost and size. In addition, it is possible to provide the paper supply device 1 that can reliably perform the push-down of the lift plate and the display of the remaining amount of paper when the paper feed cassette 2 is pulled out.

  The link member 8 engages with the lift plate 6 at one end, engages with the indicating piece 22 at the other end, and has a seesaw shape having a support shaft portion 8a at a substantially central portion between these end portions. Therefore, the push-down mechanism 10 of the lift plate 6 and the remaining paper amount display mechanism 20 can be configured with simple mechanisms, and the size of these mechanisms can be reduced. As a result, the push-down mechanism 10 of the lift plate 6 and the remaining paper amount display mechanism 20 can be stored in the paper feed cassette 2 in a compact manner. Accordingly, it is possible to further improve the downsizing and cost reduction of the paper supply device 1.

  The lift plate 6 includes a lock mechanism 30 that locks the lift plate 6 in the vicinity of the inner bottom surface of the sheet cassette 2. The lock mechanism 30 locks the lift plate 6 by engaging with the link member 8. It is not necessary to separately provide a member necessary for locking when locking the door. Therefore, the number of parts is reduced, and the downsizing mechanism 10 of the lift plate 6 can be further reduced in size and cost.

  Further, when the paper feed cassette 2 is housed in the printer 100 main body, the lock cassette 30 is provided with a lock release mechanism 40 that releases the engagement of the link member 8 and the lock mechanism 30 and releases the lock of the lift plate 6. The pickup roller 5a can be automatically brought into pressure contact with the uppermost layer of the sheet bundle when the two sheets are stored. Accordingly, the lift plate 6 can be reliably pushed down when the paper cassette 2 is pulled out by a simple mechanism using the link member 6, and the lift plate 6 can be attached to the upper side when the paper cassette 2 is stored. It is possible to carry out the process easily.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  The present invention can be used in a paper supply apparatus including a paper feed cassette that can be pulled out from the apparatus main body, and a lift plate that is arranged in the paper feed cassette and on which the paper is placed.

FIG. 3 is a right side view of the vertical cross section of the paper supply device according to the embodiment of the present invention. FIG. 6 is a partial perspective view of the front portion of the sheet feeding device as viewed from the front. FIG. 6 is a perspective view of a link member provided in the front portion of the paper supply device. FIG. 6 is a partial perspective view of the front portion of the sheet feeding device as viewed from the rear. FIG. 6 is a partial perspective view showing an engagement portion with a link member inside the paper supply device. It is a vertical cross-section rear view around the lock mechanism. The side view which shows the location of the push-down mechanism of a lift board is shown, and the state which a lift board is located in the upper side is shown. It is a side view which shows the location of the pushing down mechanism similar to FIG. 7, and shows the state in which a lift board is located below. FIG. 8 is a vertical sectional rear view around the lock mechanism similar to FIG. 6 and shows a state immediately before locking. FIG. 10 is a vertical cross-sectional rear view around the lock mechanism similar to FIG. 9 and shows a state where the lock is completed. FIG. 11 is a vertical sectional rear view around the lock mechanism similar to FIG. 10, showing a state where the lock is released. It is a perspective view of an indication piece. It is a perspective view which shows the engagement state of an indication piece and a link member. FIG. 5 is a right side view showing the remaining sheet amount display mechanism, and shows a state where the lift plate is positioned on the lower side. FIG. 15 is a right side view showing a remaining sheet amount display mechanism similar to FIG. 14 and shows a state where the lift plate is positioned on the upper side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper supply apparatus 2 Paper feed cassette 4 Front panel 6 Lift board 8 Link member 10 Push-down mechanism 11 Lift board engaging part 12 Push-down guide engaging part 13 Push-down guide member 20 Paper remaining amount display mechanism 21 Instruction piece engaging part 22 Instruction Piece 23 Display portion 30 Lock mechanism 31 Lock piece 34 Lock piece engaging portion 40 Lock release mechanism 100 Printer (equipment)

Claims (3)

In a paper supply apparatus including a paper feed cassette that can be loaded and stored and can be pulled out from the apparatus main body, and a lift plate that is disposed in the paper feed cassette and on which the paper is placed on the upper surface,
A push-down mechanism that pushes down the lift plate to the vicinity of the bottom surface of the paper feed cassette when the paper feed cassette is pulled out from the apparatus body, and a paper remaining amount display mechanism that displays the remaining amount of paper placed on the lift plate. A push-down member that engages with the lift plate and pushes it down, and a variable member that displaces the indicating piece that indicates the remaining amount of paper are integrally formed by engaging the link member and the link member. And a lock mechanism that locks the lift plate near the bottom surface of the paper feed cassette .   The link member engages with the lift plate at one end, engages with the indicating piece at the other end, and has a seesaw shape having a support shaft portion at a substantially central portion between these end portions. The paper supply device according to claim 1. When the paper feed cassette storage to the device main body to overcome the engagement between the link member and the locking mechanism, according to claim 1 or claim characterized in that it comprises an unlocking mechanism to unlock the lift plate sheet feeding apparatus according to 2.