Sheet supply device

A sheet supply device in an embodiment includes a cassette, a housing, a drawing-in device, a roller, and a guide member. The housing supports the cassette to be movable in a first direction. The drawing-in device draws the cassette into the housing. The roller is supported by one of the cassette and the housing. The guide member is supported by another of the cassette and the housing. The guide member includes a groove having the first direction as a longitudinal direction and having a third direction orthogonal to the first direction and the second direction as a width direction. The roller is disposed in a first portion in the first direction of the groove in a state in which the cassette is housed in the housing.

FIELD

Embodiments described herein relate generally to a sheet supply device.

BACKGROUND

An image forming apparatus disposed in a workplace forms an image on a sheet. The image forming apparatus includes a sheet supply device that supplies the sheet. The sheet supply device includes a cassette and a housing. The cassette is capable of storing sheets. The housing supports the cassette to be movable in a first direction. The cassette moves in the first direction to be housed in the housing. There has been a demand for a sheet supply device that can reduce a load at a cassette housing time when the cassette is housed in the housing.

DETAILED DESCRIPTION

A sheet supply device in an embodiment includes a cassette, a housing, a drawing-in device, a roller, and a guide member. The cassette is capable of storing sheets. The housing supports the cassette to be movable in a first direction. The drawing-in device draws the cassette into the housing. The roller is supported by one of the cassette and the housing. The roller is capable of rotating around a rotation axis parallel to a second direction orthogonal to the first direction. The guide member is supported by another of the cassette and the housing. The guide member includes a groove having the first direction as a longitudinal direction and having a third direction orthogonal to the first direction and the second direction as a width direction. An inner surface in the third direction of the groove is capable of coming into contact with an outer circumferential surface of the roller. The roller is disposed in a first portion in the first direction of the groove in a state in which the cassette is housed in the housing. If the cassette moves in the third direction according to the drawing-in of the cassette in the first direction by the drawing-in device, a first inner surface on a first side in the third direction of the groove in contact with the roller extends in parallel to the first direction from the first portion. If the drawing-in device starts to draw in the cassette, the roller is disposed in a second portion in the first direction of the groove. A second inner surface on a second side, which is an opposite side of the first side, in the third direction in the second portion of the groove is disposed further on the second side in the third direction than the second inner surface in the first portion.

The sheet supply device in the embodiment is explained below with reference to the drawings.

FIG.1is a perspective view of an image forming apparatus1. In this application, a Z direction, an X direction, and a Y direction of an orthogonal coordinate system and a0direction are defined as follows. The Z direction (a second direction) is the vertical direction and a +Z direction is the upward direction. The X direction and the Y direction are the horizontal direction. The X direction (a first direction) is the front-rear direction of the image forming apparatus1. A +X direction is the forward direction. The Y direction (a third direction) is the left-right direction of the image forming apparatus1. A +Y direction (a second side in the third direction) is a direction in which a sheet stored in a cassette20is supplied. A −Y direction (a first side in the third direction) is the opposite direction of the +Y direction. The θ direction is a circumferential direction in the Z direction. A +θ direction is a rotating direction of a right-handed screw advancing in a −Z direction.

The image forming apparatus1disposed in a workplace forms an image on a sheet. The image forming apparatus1is, for example, a multi function printer (MFP) or a copying machine. The image forming apparatus1may subject the image formed on the sheet to image processing. Examples of the image processing performed using the image forming apparatus1include processing for, for example, heating an image formed by decoloring toner to erase the image.

The image forming apparatus1includes a display2, a control panel unit3, an image reading unit4, an image forming unit5, and a sheet supply device10.

The display2and the control panel unit3are used by a user to perform operation input for causing the image forming apparatus1to operate. The display2displays operation content performed by the user and a message to the user.

The image reading unit4reads a document and forms an image signal of an image to be formed by the image forming unit5.

The image forming unit5forms an image on a sheet based on the operation input or a signal from the outside.

The sheet supply device (a paper feeding device)10is disposed in a lower part of the image forming apparatus1. The sheet supply device10supplies a sheet to the image forming unit5.

FIG.2is a plan view of the sheet supply device10in the embodiment. The sheet supply device10includes a cassette20and a housing (a frame)11.

The cassette20is formed in a box shape, the upper surface of which is opened. The cassette20includes a sheet storing unit21capable of storing sheets S. The sheets S are placed on a tray24of the sheet storing unit21. The sheets S are picked up one by one by a pickup roller12and supplied to the image forming unit5. The sheet S is supplied in the +Y direction from the sheet storing unit21.

The housing11supports the cassette20to be movable in the X direction. The cassette20moves in the +X direction to be drawn out from the housing11. The cassette20moves in the −X direction to be housed in the housing11. The user of the image forming apparatus1draws out the cassette20from the housing11and fills the sheets S in the cassette20. The user houses the cassette20in the housing11and causes the image forming apparatus1to start image formation.

The sheet supply device10includes a drawing-in device18for drawing the cassette20into the housing11. The drawing-in device18is set in a corner of the −X direction and the −Y direction of the housing11. The cassette20includes a pin28in the corner of the −X direction and the −Y direction. The pin28projects in the −Y direction from the cassette20.

In housing the cassette20, the user of the image forming apparatus1pushes in the cassette20in the −X direction. If the cassette20moves to near the end portion in the −X direction, the pin28enters the drawing-in device18. The drawing-in device18draws in the pin28in the −X direction making use of a restoration force of an urging member. Consequently, the cassette20is housed in the housing11. The drawing-in device18supports housing work for the cassette20by the user. The drawing-in device18houses the cassette20in a predetermined position of the housing11. Consequently, supply accuracy of the sheet S is improved.

The cassette20includes contact sections60. The contact sections60come into contact with the housing11according to the drawing-in of the cassette20by the drawing-in device18. The contact sections60include an attenuation damper61, a sheet size detecting mechanism62, a tray moving mechanism63, and a pickup roller moving mechanism (a paper feeding module)64. The attenuation damper61attenuates vibration (relaxes a shock) at a housing time of the cassette20. The sheet size detecting mechanism62detects a size of the sheets S stored in the cassette20. The tray moving mechanism63raises the tray24on which the sheets S are placed. The pickup roller moving mechanism64lowers the pickup roller12, which picks up the sheets S one by one from the cassette20, and brings the pickup roller12into contact with the sheet S.

The contact sections60are disposed side by side on the end face in the −X direction of the cassette20. The pickup roller moving mechanism64, the tray moving mechanism63, the sheet size detecting mechanism62, and the attenuation damper61are disposed in this order from the +Y direction to the −Y direction. The drawing-in device18is disposed in the −Y direction of the cassette20. The drawing-in device18is disposed in the −Y direction of the contact sections60.

The drawing-in device18causes a force in the −X direction to act on the cassette20and draws in the cassette20in the −X direction. The housing11causes a force in the +X direction in the opposite direction of the drawing-in direction of the cassette20to act on the contact sections60. The housing11causes the force in the +X direction to act on the cassette20via the contact sections60.

The force acting on the contact sections60from the housing11increases in the order of the tray moving mechanism63, the sheet size detecting mechanism62, the attenuation damper61, and the pickup roller moving mechanism64. The sheet size detecting mechanism62, the attenuation damper61, and the pickup roller moving mechanism64receive a large force from the housing11because the sheet size detecting mechanism62, the attenuation damper61, and the pickup roller moving mechanism64make use of elastic forces of coil springs. The force acting on the attenuation damper61from the housing11greatly fluctuates because the force is proportional to a square of moving speed of the cassette20.

If the cassette20is drawn into the housing11, a force in the −X direction acts on the cassette20from the drawing-in device18and a force in the +X direction acts on the cassette20from the housing11and the contact sections60. The drawing-in device18is disposed in the −Y direction of the contact sections60. Consequently, if the cassette20is drawn into the housing11, moment in the +θ direction acts on the cassette20.

The sheet supply device10includes a guide mechanism30. The guide mechanism30prevents the cassette20from turning in the +θ direction and guides the cassette20to move in the −X direction.

The guide mechanism30is disposed in a corner of the +X direction and the +Y direction of the cassette20and on the outer side of the sheet storing unit21. The guide mechanism30includes a roller32and a guide member35.

FIG.3is a plan view of the guide mechanism30.FIG.4is a perspective view of the guide mechanism30.FIG.5is a front view of the guide mechanism30.

The roller32has a cylindrical shape. The roller32is supported by the cassette20. As illustrated inFIG.5, the cassette20includes a supporting plate31parallel to an XY plane. A shaft34is set in the +Z direction of the supporting plate31. The center axis of the shaft34is parallel to the Z direction. The roller32is disposed coaxially with the shaft34. The roller32is capable of rotating around a rotation axis33parallel to the Z direction.

The guide member35is formed by a resin material or the like. The guide member35is supported by the housing11. The guide member35is fixed to the housing11by a fixing member38such as a bolt and a nut.

As illustrated inFIG.3, the guide member35includes a hook hole36. A cassette hook26engages in the hook hole36. The cassette hook26is associated with a handle on the front surface of the cassette20. If the cassette20is housed in the housing11, the user of the image forming apparatus1takes the user's hand off the handle. The cassette hook26lowers and engages in the hook hole36. Consequently, the cassette20is locked in a housed state. Since the hook hole36is formed in the guide member35, the number of components is prevented from increasing.

As illustrated inFIG.4, the guide member35is formed in a substantially U-shape in a plan view. The guide member35includes a groove40. The groove40has the X direction and a longitudinal direction and has the Y direction as a width direction. The groove40includes an opening at the end portion in the +X direction. The roller32enters the inner side of the groove40through the opening of the groove40. The guide member35includes a connecting section45that connects both the sides in the Y direction of the groove40. The connecting section45is formed at the end portion in the +Z direction of the groove40and allows the entry of the roller32. The connecting section45is formed at least at the end portion in the +X direction of the groove40and suppresses deformation near the opening of the groove40.

As illustrated inFIG.5, the groove40is formed in the +Z direction of the supporting plate31that supports the roller32. At least a part of the roller32is disposed on the inner side of the groove40. For example, a part in the +Z direction of the roller32and a part in the −Z direction of the groove40are disposed to overlap in the Z direction. As illustrated inFIG.3, the inner surface of the groove40is parallel to the Z direction and is capable of coming into contact with the outer circumferential surface of the roller32. The inner surface in the −X direction of the groove40has a cylindrical surface shape conforming to the outer circumferential surface of the roller32. A first inner surface41in the −Y direction and a second inner surface42in the +Y direction of the groove40have a plane shape.

If the cassette20is housed in the housing11, the cassette20moves in the −X direction. The roller32supported by the cassette20enters the groove40of the guide member35supported by the housing11. The roller32enters the inner side of the groove40from the opening at the end portion in the +X direction of the groove40. After the roller32enters the groove40, the drawing-in device18starts to draw in the cassette20. At a point in time of completion of the drawing-in of the cassette20, the roller32is disposed near the end portion in the −X direction of the groove40.

FIG.6is a sectional view taken along a VI-VI line inFIG.5.

In a state in which the cassette20is housed in the housing11, the roller32is disposed in a first portion51in the X direction of the groove40. The first portion51is the vicinity of the end portion in the −X direction of the groove40.

If the drawing-in device18starts to draw in the cassette20, the roller32is disposed in a second portion52in the X direction of the groove40. The second portion52is a position deeper in the −X direction from the opening at the end portion in the +X direction of the groove40. A section from the second portion52to the first portion51in the X direction of the groove40is represented as an A section. If the drawing-in device18draws in the cassette20, the roller32is located in the A section of the groove40.

As illustrated inFIG.2, if the drawing-in device18draws in the cassette20in the −X direction, moment in the +θ direction acts on the cassette20. At this time, the cassette20moves in the −Y direction in the position of the guide mechanism30. If the cassette20moves in the Y direction, a load in housing the cassette20increases.

If the cassette20moves in the −Y direction, the roller32supported by the cassette20comes into contact with the first inner surface41in the −Y direction of the groove40illustrated inFIG.6.

The first inner surface41in the −Y direction of the groove40extends in the +X direction in parallel to the X direction from the first portion51. The first inner surface41of the groove40comes into contact with the outer circumferential surface of the roller32and restricts movement of the roller32in the −Y direction. Movement of the cassette20, which supports the roller32, in the −Y direction is restricted. The roller32is capable of moving in the −X direction while rotating. Sliding resistance between the roller32and the groove40is reduced. Consequently, the load in housing the cassette20is reduced. According to the reduction in the load, a drawing-in force of the drawing-in device18can be set small. If the cassette20is drawn out, the cassette20can be drawn out with a small force resisting the drawing-in force of the drawing-in device18.

The second inner surface42in the +Y direction in the second portion52of the groove40is disposed further in the +Y direction than the second inner surface42in the first portion51. The width in the Y direction of the groove40in the first portion51is equivalent to the diameter of the roller32. If the roller32is disposed in the first portion51at the completion time of the drawing-in of the cassette20by the drawing-in device18, the cassette20is positioned in the Y direction with respect to the housing11. The width in the Y direction of the groove40in the second portion52is larger than the diameter of the roller32. Even if the roller32irregularly moves in the +Y direction at a start time of the drawing-in of the cassette20by the drawing-in device18, the roller32less easily comes into contact with the second inner surface42. Consequently, the load in housing the cassette20is reduced.

The groove40extends to the opposite side of the first portion51across the second portion52in the X direction. The groove40includes a third portion53in the +X direction of the second portion52. The first inner surface41and the second inner surface42between the second portion52and the third portion53are parallel to the X direction. The movement of the roller32in the Y direction is restricted in the same manner from before the start to the start time of the drawing-in of the cassette20by the drawing-in device18. Therefore, the cassette20is smoothly started to be drawn in by the drawing-in device18.

The groove40includes a fourth portion54at the end portion on the opposite side of the first portion51across the second portion52in the X direction. The fourth portion54is present in the +X direction of the third portion53. The fourth portion54is the end portion in the +X direction of the groove40. The groove40includes a widened section43increased in the width in the Y direction from the third portion53to the fourth portion54. The inner surface of the widened section43is a plane but may be a curved surface. Since an opening width of the end portion in the +X direction of the groove40is large, the roller32easily enters the groove40. Since the roller32is guided to the second portion52by the widened section43, the load in housing the cassette20is reduced.

The groove40includes a fifth portion55between the first portion51and the second portion52in the X direction. A first distance D1 between the first portion51and the fifth portion55in the X direction is shorter than a second distance D2 between the fifth portion55and the second portion52. The fifth portion55is present near the first portion51. The second inner surface42between the fifth portion55and the second portion52is parallel to the X direction. The width in the Y direction of the groove40between the fifth portion55and the second portion52is larger than the diameter of the roller32. Even if the roller32irregularly moves in the +Y direction while the cassette20is drawn in by the drawing-in device18, the roller32less easily comes into contact with the second inner surface42. The width in the Y direction of the groove40decreases from the fifth portion55to the first portion51. The roller32is positioned in the Y direction immediately before the completion of the drawing-in of the cassette20by the drawing-in device18. Consequently, the load in housing the cassette20is reduced.

The guide member35includes the connecting section45that connects both the sides in the Y direction of the groove40. Deformation of the groove40is suppressed by the connecting section45. Accuracy of movement restriction in the Y direction for the roller32by the groove40is improved. Consequently, the load in housing the cassette20is reduced.

The cassette20includes the contact sections60that come into contact with the housing11according to the drawing-in of the cassette20by the drawing-in device18. The contact sections60receive a force in the opposite direction of the drawing-in direction of the cassette20from the housing11. The drawing-in device18is disposed in the −Y direction of the contact sections60.

If the drawing-in device18draws in the cassette20in the −X direction, moment in the +θ direction acts on the cassette20. The cassette20moves in the −Y direction in the position of the guide mechanism30. The roller32supported by the cassette20comes into contact with the first inner surface41in the −Y direction of the groove40. The first inner surface41in the −Y direction of the groove40extends in the +X direction in parallel to the X direction from the first portion51. Movement of the cassette20in the −Y direction is restricted. Consequently, the load in housing the cassette20is reduced.

One of the contact sections60is the pickup roller moving mechanism64that brings the pickup roller12, which picks up the sheets S one by one from the cassette20, into contact with the sheet S.

One of the contact sections60is the attenuation damper61that attenuates vibration at the housing time of the cassette20.

One of the contact sections60is the sheet size detecting mechanism62that detects a size of the sheets S stored in the cassette20.

One of the contact sections60is the tray moving mechanism63that raises the tray24on which the sheets S are placed.

The contact sections60receive a force in the opposite direction of the drawing-in direction of the cassette20from the housing11. In this case as well, in the sheet supply device10in the embodiment, the load in housing the cassette20is reduced.

In the embodiment, the roller32is supported by the cassette20and the guide member35is supported by the housing11. In this case, if the cassette20moves in the −Y direction, the roller32comes into contact with the inner surface in the −Y direction of the groove40of the guide member35. In contrast, the roller32may be supported by the housing11and the guide member35may be supported by the cassette20. In this case, If the cassette20moves in the −Y direction, the inner surface in the +Y direction of the groove40of the guide member35comes into contact with the roller32. The groove40in this case is obtained by inverting the groove40in the embodiment by 180° in the θ direction.

In the embodiment, the drawing-in device18is disposed in the −Y direction of the contact sections60. In this case, if the cassette20is drawn in, the roller32comes into contact with the inner surface in the −Y direction of the groove40. In contrast, the drawing-in device18may be disposed in the +Y direction of the contact sections60. In this case, if the cassette20is drawn in, the roller32comes into contact with the inner surface in the +Y direction of the groove40. The groove40in this case is obtained by mirror-inverting the groove40in the embodiment with an XZ plane passing the center in the Y direction as a plane of symmetry.

According to the at least one embodiment explained above, the first inner surface41in the −Y direction of the groove40extends in parallel to the X direction from the first portion51. The second inner surface42in the +Y direction in the second portion52of the groove40is disposed further in the +Y direction than the second inner surface42in the first portion51. Consequently, the load in housing the cassette20can be reduced.