JP2007119175A - Sheet storage tray and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure the proper carrying state of a printing sheet by installing a side-pressure changing mechanism changing a side-pressure applied to the printing sheet according to the amount of the movement of a lift plate. <P>SOLUTION: This sheet storage tray comprises a side guide 18 movable in the direction crossing perpendicular to the stacking direction of the printing sheets 100 and providing the side-pressure to the printing sheets from the perpendicularly crossing direction, the lift plate 16 moved in the directions of approaching and separating from a sheet take-out roller 5 and pressing the printing sheets stored in a storage part 3f against the sheet take-out roller when it is moved in the direction of approaching the sheet take-out roller, and a side-pressure changing mechanism 26 changing the side-pressure of a side guide against the printing sheets according to the amount of the movement of the lift plate 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet storage tray and an image forming apparatus. More specifically, the present invention relates to a technical field in which a lateral pressure variation mechanism that varies the lateral pressure applied to the printing sheet according to the amount of movement of the lift plate is provided to ensure an appropriate conveyance state of the printing sheet.

  Examples of the image forming apparatus include a printer that performs printing on a printing sheet such as printing paper or printing film by thermal transfer, laser, or the like, a copying machine that performs copying on the printing sheet, and the like.

  In such an image forming apparatus, for example, a sheet conveying mechanism that conveys a printing sheet and a printing head that prints on the printing sheet are arranged in the apparatus main body, and is taken out from a sheet storage tray attached to the apparatus main body. In some cases, the printed sheet is conveyed by a sheet conveying mechanism and printed on the printed sheet by a printing head.

  In the image forming apparatus, when the print sheet is conveyed by the sheet conveyance mechanism, for example, if the conveyance direction of the print sheet is inclined with respect to an appropriate conveyance direction, each part of the sheet conveyance mechanism in addition to the folding or bending of the print sheet In some cases, the printing sheet is jammed, so-called paper jamming (jamming) occurs, which may hinder the conveying operation of the sheet conveying mechanism.

  In view of this, some conventional image forming apparatuses are provided with a mechanism for optimizing the conveyance direction of the print sheet (see, for example, Patent Document 1).

  In the image forming apparatus described in Patent Document 1, printing sheets (printing in Patent Document 1) are stored in a stacked manner in a sheet storage tray (the paper feed tray 20 in Patent Document 1). A lift plate (up plate 25 in Patent Document 1) that presses the paper 40) against the sheet take-out roller is rotatably provided and a pair of side guides that guide the side edges of the printing sheet (In Patent Document 1) The paper push guides 26, 26) are provided, and in a state where the printing sheet is stored in the sheet storage tray, one side guide on the movable side is urged by the urging spring to the other side guide side on the fixed side, thereby The orientation in the storage tray is optimized.

JP-A-7-285696

  However, in the above-described conventional image forming apparatus, one side guide on the movable side is always urged to the other side guide side on the fixed side with a constant urging force. Depending on the number of printing sheets stored in the tray, the urging force (side pressure) applied to each printing sheet varies.

  Accordingly, when the number of print sheets stored in the sheet storage tray is small, the lateral pressure applied to the print sheets per sheet increases, and the print sheets may be bent, deformed, or folded. .

  In order to prevent the occurrence of such a problem, it is possible to design the urging force of the urging spring based on the case where the number of printing sheets stored in the sheet storage tray is small. When the number of printing sheets stored in the sheet storage tray is large, the lateral pressure applied to the printing sheets per sheet is reduced, and sufficient lateral pressure is not applied to the printing sheets. There is a possibility that the sheet may be inclined.

  Accordingly, an object of the sheet storage tray and the image forming apparatus of the present invention is to overcome the above-described problems and to ensure an appropriate conveyance state of the print sheet.

  In order to solve the above-described problems, the sheet storage tray and the image forming apparatus of the present invention are movable in a direction orthogonal to the stacking direction of the printing sheets, and a side guide that applies a lateral pressure to the printing sheet from the orthogonal direction; A lift plate that presses the printed sheet stored in the storage unit against the sheet take-out roller when moved in a direction to move away from or in contact with the sheet take-out roller and a direction closer to the sheet take-out roller, and a movement amount of the lift plate Accordingly, a side pressure variation mechanism for varying the side pressure of the side guide with respect to the printing sheet is provided.

  Therefore, in the sheet storage tray and the image forming apparatus of the present invention, a substantially constant lateral pressure is applied to each one of the print sheets regardless of the number of print sheets stored in the sheet storage tray. .

  The sheet storage tray of the present invention is a sheet storage tray having a storage portion for storing printed sheets taken out by a sheet take-out roller in a stacked manner, and is movable in a direction orthogonal to the stacking direction of the printed sheets. The side guide for applying a lateral pressure to the print sheet from the sheet, and the sheet take-out roller for moving the print sheet stored in the storage unit when moved in the direction away from the sheet take-out roller and in the direction approaching the sheet take-out roller And a side pressure variation mechanism that varies the side pressure of the side guide with respect to the printing sheet in accordance with the amount of movement of the lift plate.

  Accordingly, a lateral pressure corresponding to the number of print sheets stored in the storage portion of the sheet storage tray can be applied to the print sheet by the side guide, so that the print sheet is prevented from being bent, deformed, folded, or the like. The sheet transport operation can be optimized.

  In the invention described in claim 2, since an urging spring is provided to urge and extend the side guide in a direction to apply a side pressure to the printing sheet according to the amount of movement of the lift plate, it is simple. With the configuration, an appropriate lateral pressure can be reliably applied to the printing sheet.

  In the invention described in claim 3, as the lateral pressure variation mechanism, a drive gear that is rotated as the lift plate moves, a cam member that is rotated according to the rotation of the drive gear, and the cam member A slider that is slidably engaged with the print sheet and that is movable in a direction perpendicular to the stacking direction of the printing sheets and that is moved in accordance with the rotational position of the cam member. Therefore, the moving force of the lift plate is reliably converted to the urging force of the urging spring, and the operation reliability of the lateral pressure variation mechanism can be ensured.

  In the invention described in claim 4, the side pressure variation mechanism includes a drive gear that is rotated as the lift plate moves, a cam member that is rotated according to the rotation of the drive gear, and a side guide. The slider is fixed and movable in the direction perpendicular to the stacking direction of the printing sheets and is moved according to the rotational position of the cam member. The slider and the cam member are connected by the biasing spring. The moving force of the plate is reliably converted into the biasing force of the biasing spring, and the reliability of the operation of the lateral pressure variation mechanism can be ensured.

  The image forming apparatus according to the present invention includes a sheet storage tray having a storage unit for storing the print sheets taken out by the sheet take-out roller in a stacked manner, and printing on the print sheet attached to the sheet storage tray and taken out from the sheet storage tray. An image forming apparatus having an apparatus main body having a printing head to perform, a side guide that is movable in a direction orthogonal to the stacking direction of the printing sheets and applies a lateral pressure to the printing sheet from the orthogonal direction, and a sheet take-out A lift plate that presses the print sheet stored in the storage unit against the sheet take-out roller when moved in a direction to move away from or in contact with the roller and a direction closer to the sheet take-out roller, and according to the amount of movement of the lift plate And a side pressure variation mechanism that varies the side pressure of the side guide with respect to the printing sheet.

  Accordingly, a lateral pressure corresponding to the number of print sheets stored in the storage portion of the sheet storage tray can be applied to the print sheet by the side guide, so that the print sheet is prevented from being bent, deformed, folded, or the like. The sheet transport operation can be optimized.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  In the embodiment described below, the image forming apparatus of the present invention is applied to a printer, and the sheet storage tray of the present invention is applied to a sheet storage tray provided in the printer.

  The scope of application of the present invention is not limited to a printer and a sheet storage tray provided therein, but various image forming apparatuses having a function of forming an image such as a copying machine and various sheets provided therein. It can be widely applied to storage trays.

  The image forming apparatus (printer) 1 includes an apparatus main body 2 and a sheet storage tray 3 that is attached to the apparatus main body 2 and stores printing sheets 100, 100,... (See FIG. 1).

  The apparatus main body 2 is mounted on a mounting table such as a desk or table, and required parts are arranged in the outer casing 4.

  A sheet take-out roller 5 is rotatably supported in the outer casing 4, and a discharge roller 6 is rotatably supported above the sheet take-out roller 5 so as to be movable in a direction away from and in contact with the sheet take-out roller 5.

  Behind the sheet take-out roller 5, a feed roller 7, a separation pad 8, a pair of transport rollers 9, 9, and a platen roller 10 are arranged in this order.

  The feed roller 7 and the separation pad 8 are positioned up and down, and can be rotated in a direction in which the separation pad 8 is separated from and in contact with the feed roller 7. The separation pad 8 is provided with a separation portion made of, for example, a rubber material, and has a function of separating the printing sheets 100, 100,.

  An ink ribbon supply mechanism 11 is disposed in the outer casing 4. The ink ribbon supply mechanism 11 includes a supply roller 11a and a take-up roller 11b that takes up the ink ribbon 200 supplied from the supply reeler 11a, and the ink ribbon 200 is fixed between the supply roller 11a and the take-up roller 11b. A plurality of tension rollers 11c, 11c,...

  A head driving mechanism 12 is disposed on the inner side of the outer casing 4. The head drive mechanism 12 has a cam gear 13 and a head drive arm 14 that is rotated as the cam gear 13 rotates.

  The cam gear 13 has a cam groove 13a formed in a predetermined shape.

  The head drive arm 14 is provided with a cam slide pin 14a slidably engaged with the cam groove 13a. A print head 14 b is provided at the front end of the head drive arm 14, and the print head 14 b is positioned to face the outer peripheral surface of the platen roller 10.

  When the cam gear 13 is rotated in the head driving mechanism 12, the position of the cam sliding pin 14a in the cam groove 13a is changed with the rotation of the cam gear 13, and the head driving arm 14 is rotated to rotate the printing head 14b. Is moved toward and away from the platen roller 10.

  In the image forming apparatus 1, a sheet discharge unit 15 is formed on the front side of the sheet take-out roller 5.

  In the image forming apparatus 1, when the printing operation is started, the printing sheet 100 stored in the sheet storage tray 3 is taken out by the sheet take-out roller 5, passes between the feed roller 7 and the separation pad 8, the transport roller 9, 9 is conveyed to the platen roller 10 side (the conveyance path of the printing sheet 100 is indicated by a broken line in FIG. 1).

  When the printing sheet 100 is conveyed to the platen roller 10, the head driving arm 14 is rotated and the ink ribbon 200 is pressed against the printing sheet 100 by the printing head 14b, and printing by the printing head 14b is performed on the printing sheet 100. Is called.

  The printing sheet 100 on which printing has been performed is once conveyed to the rear of the platen roller 10 and is conveyed again to the sheet take-out roller 5 side by reversing the platen roller 10 and the conveyance rollers 9 and 9. The printing sheet 100 conveyed to the sheet extraction roller 5 side is conveyed to the sheet discharge unit 15 by the sheet extraction roller 5 and the discharge roller 6. When the printing sheet 100 is discharged to the discharge unit 15, the discharge roller 6 is moved in a direction approaching the sheet extraction roller 5, and the printing sheet 100 is fed forward by the rotation of the sheet extraction roller 5 and the discharge roller 6.

  As shown in FIGS. 2 to 4, the sheet storage tray 3 includes a bottom surface portion 3a and one of a front surface portion 3b, a rear surface portion 3c, and a bottom surface portion 3a that are vertically raised from both front and rear side edges of the bottom surface portion 3a. And a side surface portion 3d raised vertically from the rear end portion of the side edge. Guide pins 3e and 3e protruding downward are provided on the lower surface of the bottom surface portion 3a so as to be separated from each other in the front-rear direction.

  The internal space of the sheet storage tray 3 is formed as a storage portion 3f for storing the printing sheets 100, 100,.

  A lift plate 16 is rotatably supported on the bottom surface portion 3a of the sheet storage tray 3, for example. The lift plate 16 is rotated by a drive motor (not shown), and the printing sheets 100, 100,... Are stacked on the lift plate 16.

  The lift plate 16 has a front end portion as a rotation fulcrum 16a, and is rotated with the rotation fulcrum 16a as a reference, whereby the rear end portion is moved in a direction in which the sheet take-out roller 5 is separated from (see FIG. 2). reference).

  When the printing operation is performed on the printing sheet 100 in the image forming apparatus 1, the lift plate 16 is rotated to an angle corresponding to the number of printing sheets 100, 100,... Stored in the storage unit 3 f of the sheet storage tray 3. The That is, when the number of stored printing sheets 100, 100,... Is large, the total thickness of the printing sheets 100, 100,. ), When the number of stored printing sheets 100, 100,... Is small, the rotation angle of the lift plate 16 is large (see the solid line in FIG. 2) because the total thickness of the printing sheets 100, 100,.

  Side guides 17 and 18 are disposed on the left and right sides of the sheet storage tray 3. The side guide 17 is fixed, and the side guide 18 is movable in the left-right direction (see FIGS. 3 and 4).

  A driving gear 19 and a gear body 20 are rotatably supported on the side surface portion 3d of the sheet storage tray 3 separately. The drive gear 19 is formed in a fan shape, and its rotation axis is formed coaxially with the rotation axis of the lift plate 16. The gear body 20 is formed by integrally forming a driven gear 20a and a first bevel gear 20b, and a drive gear 19 is engaged with the driven gear 20a.

  An interlocking gear 21 is rotatably supported on the bottom surface portion 3 a of the sheet storage tray 3. The interlocking gear 21 includes a rotating shaft 21a and a second bevel gear 21b that is rotated about the rotating shaft 21a. The second bevel gear 21 b is meshed with the first bevel gear 20 b of the gear body 20.

  A cam member 22 is rotatably supported on the bottom surface portion 3 a of the sheet storage tray 3. The cam member 22 includes a drive shaft 22a and a cam disk portion 22b that is rotated with reference to the drive shaft 22a. The drive shaft 22a is provided at a position deviated from the center of the cam disk portion 22b.

  A drive belt 23 is wound between the rotation shaft 21 a of the interlocking gear 21 and the drive shaft 22 a of the cam member 22.

  A slider 24 is supported on the bottom surface portion 3a of the sheet storage tray 3 so as to be movable in the left-right direction. The slider 24 has long guided holes 24a and 24a which are elongated to the left and right, and guide pins 3e and 3e provided on the bottom surface portion 3a of the sheet storage tray 3 are inserted into the guided holes 24a and 24a, respectively.

  The slider 24 is connected to the movable side guide 18 by biasing springs 25, 25 that can expand and contract in the left-right direction, and the cam member 22 is positioned between the biasing springs 25, 25. The urging springs 25 and 25 are, for example, tension coil springs. The urging springs 25 and 25 urge the side guide 18 and the slider 24 toward each other in the left-right direction, and the side edge 24 b of the slider 24 is the cam member 22. The cam disk portion 22b is always in contact with the outer peripheral surface.

  The driving gear 19, the gear body 20, the interlocking gear 21, the cam member 22, the driving belt 23, the slider 24, and the urging springs 25, 25 described above are the lateral pressures of the side guide 18 against the printing sheets 100, 100,. This is a component of the side pressure variation mechanism 26 that varies the pressure.

  In the image forming apparatus 1, when the printing operation is started, the lift plate 16 is rotated to press the printing sheet 100 positioned at the uppermost layer against the sheet take-out roller 5, and the print take-out sheet 5 stores the print sheet 100 in the sheet. It is taken out from the tray 3. At this time, the drive gear 19 is rotated integrally with the lift plate 16, and the rotational force of the drive gear 19 is sequentially transmitted to the cam member 22 via the gear body 20, the interlocking gear 21 and the drive belt 23. The member 22 is rotated by an angle corresponding to the rotation angle of the lift plate 16.

  When the cam member 22 is rotated, the slider 24 in contact with the cam member 22 is moved in the left-right direction, and the biasing springs 25, 25 are expanded and contracted. Therefore, the urging force of the urging springs 25, 25 against the side guide 18 is changed, and the side pressure of the side guide 18 against the printing sheets 100, 100,... Is changed according to the rotation angle of the lift plate 16.

  The side pressure of the side guide 18 with respect to the printing sheets 100, 100,... Is set to decrease as the rotation angle of the lift plate 16 increases.

  For example, at the start of the printing operation when the number of printing sheets 100, 100,... .5 °, the amount of extension of the biasing springs 25, 25 is increased, and the side pressure of the side guide 18 with respect to the printing sheets 100, 100,... Is increased (see FIGS. 3 and 4).

  Further, for example, at the start of the printing operation when the number of stored printing sheets 100, 100,... The extension amount of the urging springs 25, 25 is made smaller than when the number of stored sheets is about 100 sheets, and the side pressure of the side guide 18 with respect to the printing sheets 100, 100,. (See FIGS. 5 and 6).

  Further, for example, at the start of the printing operation when the number of print sheets 100 stored in the storage portion 3f of the sheet storage tray 3 is one sheet, the rotation angle of the lift plate is about 11.1 ° with respect to the horizontal direction. The extension amount of the urging springs 25, 25 is made smaller than when the number of stored sheets is about 30 sheets, and the side pressure of the side guide 18 against the printing sheets 100, 100,. ).

  The urging force of the urging springs 25 and 25 is set so that the side pressure of the side guide 18 is substantially the same with respect to the printing sheet 100 per sheet regardless of the rotation angle of the lift plate 16. .

  As described above, as the side pressure variation mechanism 26, the drive gear 19 that rotates as the lift plate 16 rotates, the cam member 22 that rotates according to the rotation of the drive gear 19, and the cam member 22 By providing a slider 24 that is slidably engaged and moved according to the rotational position of the cam member 22, and biasing springs 25, 25 that connect the slider 24 and the side guide 18, the rotation of the lift plate 16 is provided. The power is reliably converted into the urging force of the urging springs 25, 25, and the reliability of the operation of the side pressure fluctuation mechanism 26 can be ensured.

  In addition, although the example which used the tension | pulling coil spring as the biasing springs 25 and 25 was shown above, the biasing springs 25 and 25 are not restricted to a tension coil spring, The side guide 18 to the side guide 17 side is shown. Any material that imparts an urging force may be used. For example, rubber, a leaf spring, or the like may be used.

  Further, the number of urging springs 25 is not limited to two and can be any number.

  Next, a modified example of the lateral pressure variation mechanism will be described (see FIGS. 9 and 10).

  The side pressure fluctuation mechanism 26A according to the modification shown below differs from the above-described side pressure fluctuation mechanism 26 only in that the connection parts of the biasing spring and the connection state of the slider and the side guide are different. Only different portions compared to the variation mechanism 26 will be described in detail, and the other portions will be denoted by the same reference numerals as the same portions in the side pressure variation mechanism 26 and description thereof will be omitted.

  The side pressure variation mechanism 26 </ b> A includes a drive gear 19, a gear body 20, an interlocking gear 21, a cam member 22, a drive belt 23, a slider 24, and an urging spring 25.

  A cam member 22 is rotatably supported on the bottom surface 3 a of the sheet storage tray 3 on the opposite side of the side guide 18 with the slider 24 interposed therebetween.

  The slider 24 is connected to the cam disk portion 22b of the cam member 22 by an urging spring 25 that can be expanded and contracted to the left and right. The slider 24 and the side guide 18 are fixed. The side guide 18 and the slider 24 are biased toward the cam member 22 by the biasing spring 25.

  In the image forming apparatus 1, when the printing operation is started, the lift plate 16 is rotated to press the printing sheet 100 positioned at the uppermost layer against the sheet take-out roller 5, and the print take-out sheet 5 stores the print sheet 100 in the sheet. It is taken out from the tray 3. At this time, the drive gear 19 is rotated integrally with the lift plate 16, and the rotational force of the drive gear 19 is sequentially transmitted to the cam member 22 via the gear body 20, the interlocking gear 21 and the drive belt 23. The member 22 is rotated by an angle corresponding to the rotation angle of the lift plate 16.

  When the cam member 22 is rotated, the connecting position of the urging spring 25 in the cam member 22 is changed in the left-right direction and is expanded and contracted. Therefore, the urging force of the urging spring 25 against the side guide 18 is changed, and the side pressure of the side guide 18 against the printing sheets 100, 100,... Is changed according to the rotation angle of the lift plate 16.

  In the side pressure fluctuation mechanism 26A, unlike the side pressure fluctuation mechanism 26, the slider 24 and the side guide 18 are fixed, and therefore the side pressure against the printing sheets 100, 100,. When the biasing spring 25 is expanded and contracted by the rotation of the cam member 22, the slider 24 is not moved greatly in the left-right direction.

  In the side pressure variation mechanism 26A, the slider 24 and the side guide 18 may be integrally formed. When the slider 24 and the side guide 18 are integrally formed, the number of parts can be reduced.

  As described above, the side pressure variation mechanism 26 </ b> A is connected to the drive gear 19 that rotates as the lift plate 16 rotates, the cam member 22 that rotates according to the rotation of the drive gear 19, and the side guide 18. By providing the slider 24 that is moved in accordance with the rotational position of the cam member 22 and the biasing spring 25 that connects the slider 24 and the cam member 22, the rotational force of the lift plate 16 is reliably biased by the biasing spring 25. Therefore, the reliability of the operation of the lateral pressure variation mechanism 26A can be ensured.

  As described above, in the image forming apparatus 1, the side pressure fluctuation that varies the side pressure of the side guide 18 toward the printing sheets 100, 100,... According to the rotation angle (rotation amount) of the lift plate 16. Since the mechanisms 26 and 26A are provided, a side pressure corresponding to the number of stored printing sheets 100, 100,... With respect to the storage portion 3f of the sheet storage tray 3 is applied to the printing sheets 100, 100,. It can be given to.

  Therefore, it is possible to prevent the printing sheets 100, 100,... From being bent, deformed, bent or the like and to optimize the conveying operation of the printing sheets 100, 100,.

  Further, since the lateral pressure is applied to the printing sheets 100, 100,... Using the biasing springs 25, 25 that expand and contract in accordance with the rotation angle of the lift plate 16, the printing sheet is surely secured with a simple configuration. An appropriate lateral pressure can be applied to 100, 100,.

  In the above example, the side pressure variation mechanisms 26 and 26A are provided in the sheet storage tray 3. However, the side pressure variation mechanisms 26 and 26A may be provided in the apparatus main body 2. In this case, for example, the side guide 18 is also provided in a movable state in the apparatus main body 2, and the lift plate 16 and the drive gear 19 are connected when the sheet storage tray 3 is attached to the apparatus main body 2. Configure.

  By providing the side pressure variation mechanisms 26 and 26A in the apparatus main body 2, the sheet storage tray 3 becomes light, and the attachment and release of the sheet storage tray 3 to the apparatus main body 2 can be performed easily and smoothly.

  In the above description, the lift plate 16 is rotated as an example. For example, the lift plate 16 is moved in the vertical direction (the stacking direction of the printing sheets 100, 100,...). It is also possible to adopt a configuration in which the side pressure of the side guide 18 against the printing sheets 100, 100,. In this case, for example, the drive gear 19 is rotated according to the movement of the lift plate 16.

  Further, in the above description, the configuration in which only one of the side guides 17 and 18 is movable is shown, but both the side guides 17 and 18 may be movable.

  The above-described directions in the up / down / left / right and front / rear directions are for convenience of explanation, and the application of the present invention is not limited to these directions.

  The specific shapes and structures of the respective parts shown in the above-described best mode are merely examples of the implementation of the present invention, and the technical scope of the present invention is limited by these. It should not be interpreted in a general way.

FIG. 2 to FIG. 10 show the best mode of the present invention, and this figure is a schematic side view of an image forming apparatus. It is a conceptual diagram which shows the state in which a lift board is rotated. It is a side view which shows the sheet | seat storage tray in the state where the rotation angle of a lift board is small. It is a bottom view showing a sheet storage tray in a state where the rotation angle of the lift plate is small. FIG. 4 is a side view showing the sheet storage tray in a state where the rotation angle of the lift plate is made larger than the state of FIG. 3. FIG. 5 is a bottom view showing the sheet storage tray in a state where the rotation angle of the lift plate is made larger than the state of FIG. 4. FIG. 6 is a side view showing the sheet storage tray in a state where the rotation angle of the lift plate is made larger than the state of FIG. 5. It is a bottom view which shows the sheet | seat storage tray in the state in which the rotation angle of the lift board was made larger than the state of FIG. FIG. 10 shows a modification of the lateral pressure variation mechanism together with FIG. 10, and this figure is a side view. It is a bottom view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Apparatus main body, 3 ... Sheet storage tray, 3f ... Storage part, 5 ... Sheet taking-out roller, 14b ... Printing head, 16 ... Lift plate, 18 ... Side guide, 19 ... Drive gear, 22 ... Cam member, 24 ... slider, 25 ... biasing spring, 26 ... lateral pressure variation mechanism, 100 ... printing sheet, 26A ... lateral pressure variation mechanism

Claims (5)

A sheet storage tray having a storage portion for storing the printing sheets taken out by the sheet take-out roller in a stack,
A side guide that is movable in a direction perpendicular to the stacking direction of the printing sheets and applies a lateral pressure to the printing sheet from the orthogonal direction;
A lift plate that is moved in a direction away from and in contact with the sheet take-out roller and presses the print sheet stored in the storage unit against the sheet take-out roller when moved in a direction approaching the sheet take-out roller;
A sheet storage tray, comprising: a side pressure fluctuation mechanism that fluctuates a side pressure of the side guide with respect to the printing sheet in accordance with a movement amount of the lift plate. 2. The sheet storage tray according to claim 1, further comprising an urging spring configured to expand and contract in accordance with a movement amount of the lift plate and urge the side guide in a direction in which a lateral pressure is applied to the printing sheet. As the side pressure fluctuation mechanism,
A drive gear that rotates as the lift plate moves,
A cam member rotated in accordance with the rotation of the drive gear;
A slider that is slidably engaged with the cam member and is movable in a direction perpendicular to the stacking direction of the printing sheets and is moved according to the rotational position of the cam member;
The sheet storage tray according to claim 2, wherein the slider and the side guide are connected by the biasing spring. As the side pressure fluctuation mechanism,
A drive gear that rotates as the lift plate moves,
A cam member rotated in accordance with the rotation of the drive gear;
A slider fixed to the side guide and movable in a direction orthogonal to the stacking direction of the printing sheets and moved according to the rotational position of the cam member;
The sheet storage tray according to claim 2, wherein the slider and the cam member are connected by the biasing spring. An apparatus main body having a sheet storage tray having a storage section for storing print sheets taken out by a sheet take-out roller in a stacked manner, and a print head on which the sheet storage tray is mounted and performing printing on a print sheet taken out from the sheet storage tray An image forming apparatus comprising:
A side guide that is movable in a direction perpendicular to the stacking direction of the printing sheets and applies a lateral pressure to the printing sheet from the orthogonal direction;
A lift plate that is moved in a direction away from and in contact with the sheet take-out roller and presses the print sheet stored in the storage unit against the sheet take-out roller when moved in a direction approaching the sheet take-out roller;
An image forming apparatus comprising: a side pressure fluctuation mechanism that fluctuates a side pressure of the side guide with respect to the printing sheet in accordance with a movement amount of the lift plate.

Images