Paper feed apparatus and image forming apparatus

A paper feed apparatus includes a paper feeding roller and a separating pad for separating paper one by one and feeding the paper. This separating pad is supported by a separating pad holder to be abutted onto the paper feeding roller with a predetermined pressure. Furthermore, the separating pad holder is provided with a weight member in a loosely-fitted state.

CROSS REFERENCE OF RELATED APPLICATION

The disclosure of Japanese Patent Application No. 2015-119649 filed on Jun. 12, 2015 is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a paper feed apparatus and an image forming apparatus, and more specifically, a paper feed apparatus and an image forming apparatus, which separates paper placed in a paper placing tray one by one and feeds the paper.

Description of the Related Art

An example of a related art is disclosed in Japanese Patent Application Laying-open No. 2007-197171 [B65H 3/52] laid-open on Aug. 9, 2007 (Literature 1). A paper feed apparatus of Literature 1 is mounted with a sheet member separation apparatus comprising a paper feeding roller that feeds a sheet member, a holding arm (support member) having a friction pad (separating member) that separates the sheet member and a base member that is a base portion. This sheet member separation apparatus comprises a rotation holding portion that is constituted with a rotation shaft having a concentric cross-section that is tapered toward a shaft end portion and a concave rotation bearing portion that has a concentric cross-section that is tapered toward an inner portion and is to be fit to the rotation shaft. Then, the holding arm having the friction pad is sandwiched with pressure by this rotation holding portion.

In the structure that suppresses a minute vibration of the separating member (and support member) by sandwiching the support member of the separation member with pressured, it is necessary to make a pressure-sandwiching force by the rotation holding portion large to appropriately suppress the minute vibration of the separating member. However, since the rotation holding portion needs to hold the support member free rotation, there is a limit in enlarging the pressure-sandwiching force. Therefore, suppression of the minute vibration becomes insufficient with the technology of Literature 1, and therefore, there is a possibility the minute vibration of the separating member and a sound (vibration sound) accompanying the minute vibration cannot be adequately suppressed. Especially, since a frictional resistance becomes high when the paper feeding roller and the separating member rub directly in a state where there is no paper at the time of paper feeding, the minute vibration of the separating member is increased and a possibility that the sound may occur also becomes high.

SUMMARY OF THE INVENTION

Therefore, it is a primary object of the present invention to provide a novel paper feed apparatus and image forming apparatus.

It is another object of the present invention to provide a paper feed apparatus and image forming apparatus, capable of adequately suppressing a minute vibration of a separating member and a sound accompanying the minute vibration.

A first invention is a paper feed apparatus that feeds a paper placed in a paper placing tray, comprising: a paper feeding roller that feeds a paper; a separating member that separates a paper fed by the paper feeding roller one by one; a support member that supports the separating member to be abutted onto the paper feeding roller with a predetermined pressure; and a weight member that is provided to the support member in a loosely-fitted state.

In the first invention, the paper feed apparatus is an apparatus that feeds a paper placed in the paper placing tray, and is used in an image forming apparatus such as a copying machine, a facsimile, a printer, a multifunction machine compounding these, etc. The paper feed apparatus comprises the paper feed roller and the separating member for separating a paper one by one and feeding the paper. The separating member is a separating pad etc., and is supported by the support member to be abutted onto the paper feeding roller with the predetermined pressure. Then, this support member is provided with the weight member in the loosely-fitted state.

In such the paper feed apparatus, even if the separating member and the support member minute-vibrate at the time of paper feeding, the minute vibration of separating member can be attenuated promptly since the weight member in the loosely-fitted state moves out of synchronization with the support member. Furthermore, since it does not perform making the separating member into a low frictional resistance or decreasing an abutting pressure of the separating member against the paper feeding roller in order to suppress the minute vibration of the separating member, paper separation and feeding performance by the paper feeding roller and the separating member does not fall.

According to the first invention, it is possible to adequately suppress the minute vibration of separating member and the sound accompanying the minute vibration while keeping the paper separation and feeding performance with simple structure of providing the weight member to the support member of the separating member in a loosely-fitted state.

A second invention is according to the first invention, wherein the support member has a loosely-fitting shaft and two engaging portions that are provided at a predetermined interval in an axial direction of the loosely-fitting shaft, and the weight member has a loosely-fitting hole into which the loosely-fitting shaft is inserted.

In the second invention, the support member has the loosely-fitting shaft extending in a direction that is the same or approximately the same direction as a direction of the minute vibration of separating member, for example, and the two engaging portions provided at the predetermined interval in the axial direction of the loosely-fitting shaft. On the other hand, the weight member is formed with the loosely-fitting hole into which the loosely-fitting shaft is inserted. Then, by fitting the loosely-fitting shaft and the loosely-fitting hole to each other between the two engaging portions, the weight member is attached to the support member in the loosely-fitted state, whereby it is brought into a state where the weight member can move (minute-vibrate) in the direction of the minute vibration of separating member. Accordingly, the minute vibration of separating member and the sound accompanying it can be suppressed adequately.

A third invention is according to the first invention, wherein the support member has a loosely-fitting hole, and the weight member has a loosely-fitting shaft that is inserted into the loosely-fitting hole and two engaging portions provided at a predetermined interval in an axial direction of the loosely-fitting shaft.

In the third invention, the support member is formed with the loosely-fitting hole extending in a direction that is the same or approximately the same as the direction of the minute vibration of separation member, for example. On the other hand, the weight member is formed so as to have the loosely-fitting shaft that is inserted into the loosely-fitting hole and the two engaging portions provided at the predetermined interval in an axial direction of the loosely-fitting shaft. Then, by fitting the loosely-fitting shaft and the loosely-fitting hole to each other between the two engaging portions, the weight member is attached to the support member in the loosely-fitted state, whereby it is brought into a state where the weight member can move (minute-vibrate) in the direction of the minute vibration of separating member. Accordingly, the minute vibration of separating member and the sound accompanying it can be suppressed adequately.

A fourth invention is according to the first invention, wherein the support member is provided in a rockable manner with a support shaft that is provided in a position deviated from the separating member to an upstream side or a downstream side in a paper feeding direction as a fulcrum, and the weight member is arranged in a position near the separating member than the support shaft in the paper feeding direction.

In the fourth invention, the support member is provided in a rockable manner with the support shaft as a fulcrum and the separating member is provided in the position deviated from the support shaft to the upstream side or the downstream side in the paper feeding direction. Then, the weight member is arranged in the position near the separating member than the support shaft of the support member, that is, a position far from the support shaft.

According to the fourth invention, a minute vibration suppressing effect is shown more largely.

A fifth invention is a paper feed apparatus that feeds a paper placed in a paper placing tray, comprising: a paper feeding roller that feeds a paper; a separating member that separates a paper fed by the paper feeding roller one by one; a support member that supports the separating member to be abutted onto the paper feeding roller with a predetermined pressure and has an accommodating portion; and a weight member that is accommodated within the accommodating potion in a movable state.

In the fifth invention, the paper feed apparatus is an apparatus that feeds a paper placed in the paper placing tray, and is used in an image forming apparatus such as a copying machine, a facsimile, a printer, a multifunction machine compounding these, etc. The paper feed apparatus comprises the feed roller and the separating member for separating a paper one by one and feeding the paper. The separating member is a separating pad etc., and is supported by the support member to be abutted onto the paper feeding roller with the predetermined pressure. The accommodating portion is formed in the support member. Then, the weight member is accommodated in the accommodating portion in a state where there is a room leaving a part of an internal volume, and therefore, the weight member is brought into a state where the weight member can move (minute-vibrate) in a direction of a minute vibration of separating member within the accommodating portion.

In such the paper feed apparatus, even if the separating member and the support member minute-vibrate at the time of paper feeding, the minute vibration of separating member can be attenuated promptly since the weight member is moved out of synchronization with the support member. Furthermore, since it does not perform making the separating member into a low frictional resistance or decreasing an abutting pressure of the separating member against the paper feeding roller in order to suppress the minute vibration of separating member, paper separation and feeding performance by the paper feeding roller and the separating member does not fall.

According to the fifth invention, it is possible to adequately suppress the minute vibration of the separating member and the sound accompanying the minute vibration while keeping the paper separation and feeding performance with simple structure of accommodating the weight member in a movable state within the accommodating portion.

A sixth invention is according to the fifth invention, wherein the weight member is constituted with a plurality of granular bodies.

In the sixth invention, a plurality of granular bodies such as iron powder are used as the weight member.

A seventh invention is an image forming apparatus comprising the paper feed apparatus according to the first invention.

According to the seventh invention, the same action and effect as those of the first invention can be effectuated, and it is possible to adequately suppress the minute vibration of separating member and the sound accompanying it.

An eighth invention is an image forming apparatus comprising the paper feed apparatus according to the fifth invention.

According to the eighth invention, the same action and effect as those of the first invention can be effectuated, and it is possible to adequately suppress the minute vibration of separating member and the sound accompanying it.

DETAILED DESCRIPTION OF NON-LIMITING EXAMPLE EMBODIMENTS

With referring toFIG. 1andFIG. 2, a paper feed apparatus10that is one embodiment according to the present invention is used in an image forming apparatus such as a copying machine, a facsimile, a printer, a multifunction machine compounding these, etc. As details will be described later, the paper feed apparatus10comprises a paper feeding roller52, a separation unit56, etc., and feeds an original (paper) placed in an original placing tray (paper placing tray)44to an image reading position34one by one. In this embodiment, an example that the paper feed apparatus10is applied to a multifunction machine100having a copying machine function, a printer function, a scanner function, a facsimile function, etc. is shown.

First, structure of the multifunction machine100is roughly described. As shown inFIG. 1andFIG. 2, the multifunction machine100includes the paper feed apparatus10, a multifunction machine body12and an image reading apparatus14. A control portion20that controls operations of respective components of the multifunction machine100is provided in a predetermined position in the multifunction machine body12. The control portion20comprises a CPU, memories, etc., and transmits control signals according to an input operation to an operating portion22by a touch panel, operating button, etc. to respective components of the multifunction machine100to make the multifunction machine100perform a various kinds of operations.

Furthermore, an image forming portion24that is provided with a photoreceptor drum, a charging apparatus, an exposure apparatus, a developing apparatus, a transfer apparatus, a fixing apparatus, etc. is incorporated within the multifunction machine body12. The image forming portion24forms an image on a recording paper that is fed from a paper cassette26or the like by an electrophotography system, and discharges the recording paper on which the image has been formed onto a discharging tray28. As image data for forming an image on the recording paper, image data that is read by an image reading portion32of the image reading apparatus14, image data that is transmitted by an external computer, etc. can be utilized.

The image reading apparatus14comprises a housing30that has an original platen30amade of a transparent material on a top surface thereof. Within the housing30, there is provided with the image reading portion32that comprises a light source, a plurality of mirrors, a focusing lens, a line sensor, etc. In the image reading portion32, an original surface is exposed by the light source, and a reflected light that is reflected by the original surface is conducted to the focusing lens by the plurality of mirrors. Then, the reflected light is focused onto photoreceptors of the line sensor by the focusing lens. In the line sensor, a luminance and a chromaticity of the reflected light being focused onto the photoreceptors are detected to produce image data based on the image of the original surface. As the line sensor, a CCD (Charge Coupled Device), a CIS (Contact Image Sensor) or the like can be used.

In addition, the image reading portion32has a home position at a position opposite to an image reading position34, and in a case where an image of an original placed in the original placing tray44is to be read, the image reading portion32reads an image on the original surface when the original passes the image reading position34, thereby to acquire image data. Furthermore, in a case where an image of an original that is put on the original platen30aon the top surface of the housing30is to be read, by adequately moving the light source, mirrors, etc. beneath the original platen30a, an image of the original is read, thereby to acquire image data.

In addition, a platen cover36is attached to the original platen30aof the image reading apparatus14in an openable/closable manner via a hinge. The paper feed apparatus10is provided on the platen cover36.

In the following, structure of the paper feed apparatus10will be specifically described by suitably referring toFIG. 2toFIG. 7. In addition, it should be noted that a term “upstream” or “downstream” means, in this specification, an upstream or a downstream in an original feeding direction (paper feeding direction).

As shown inFIG. 2, the paper feed apparatus10is an automatic document feeder (ADF) that successively feeds an original that an image thereon is to be read from the original placing tray44to the paper discharging tray46via the image reading position34, and is provided with a main body casing40that is made of a synthetic resin and forms an outer shell. A paper feeding port42is formed in an upper portion of the main body casing40and the original placing tray44is provided so as to extend from the paper feeding port42obliquely upward. The original placing tray44includes a tabular rotating portion44athat is provided in a rotatable manner, the paper feeding port42is opened or closed by rotating the rotating portion44a. Furthermore, a pair of side guides48that are movable in a width direction are provided on an upper surface of the original placing tray44. The side guides48regulate and align the original that is placed in the original placing tray44from both sides.

In the main body casing40, a pickup roller50that picks-up an original placed in the original placing tray44is provided to be movable upward and downward. In a downstream side of the pickup roller50, there is provided with a paper feeding roller52that feeds-out the original that is picked-up from the original placing tray44by the pickup roller50. A pickup holder54is provided so as to cover peripheries and upper parts of the pickup roller50and the paper feeding roller52. The pickup roller50is supported by the pickup holder56to be movable upward and downward around the rotation shaft of the paper feeding roller52.

Furthermore, the separation unit56for preventing a multi-feed of an original is provided in a position opposite to the paper feeding roller52. As details will be described later, the separation unit56comprises a separating pad58that is a separating member that separates an original fed-out by the paper feeding roller52one by one, a separating pad holder60that is a support member that supports the separating pad58, a weight member62, etc.

Furthermore, in a downstream side of the paper feeding roller52, a plurality of feeding rollers64and a paper discharging roller66are provided, and within the main body casing40, an original feeding path70that extends from the paper feeding port42to a paper discharging port68via the image reading position34is formed. The original fed-out by the paper feeding roller52to an original feeding path70is fed by the plurality of feeding rollers64to the image reading position34. Then, an image is read by the image reading portion32of the image reading apparatus14while the original is being fed above the image reading position34. The original that is passed through the image reading position34is guided to the paper discharging port68by the feeding rollers64and the paper discharging roller66, and is discharged onto the paper discharging tray46.

Subsequently, structure of the separation unit56will be described specifically. As shown inFIG. 3-FIG. 7, the separation unit56comprises the separating pad58and separating pad holder60, etc.

The separating pad58is a member that has a shape of a rectangle plate, and is formed of a material having a high coefficient of friction such as a urethane resin etc. The separating pad58is supported by the separating pad holder60to be abutted onto the paper feeding roller52with a predetermined pressure.

The separating pad holder60is formed of a synthetic resin etc., and comprises an arm portion80extending in the original feeding direction. A tabular pad attaching portion82having an upper surface to which the separating pad58is secured is formed in a downstream side end of the arm portion80. Furthermore, a support shaft84is formed in an upstream side end of the arm portion80, that is, in a position deviated from the separating pad58to an upstream side. The support shaft84is supported by a bearing86rotatably, and the separating pad holder60is made to be rockable with the support shaft84as a fulcrum. Furthermore, a spring attaching portion88having a shape of an approximately cylinder is formed on a lower surface of the pad attaching portion82. An elastic member such as a compression spring90is attached to the spring attaching portion88. Then, an upper surface of the separating pad58is abutted onto an outer peripheral surface of the paper feeding roller52with a predetermined pressure by pushing up a downstream side end of the separating pad holder60by the compression spring90, whereby a nip portion for paper-separation and feeding is formed between the separating pad58and the paper feeding roller52.

Furthermore, the separating pad58is made such that a coefficient of friction of an upper surface with the original is smaller than a coefficient of friction of the outer peripheral surface of the paper feeding roller52with the original, but larger than a coefficient of friction between originals with each other. Accordingly, an original can be separated one by one in the nip portion formed by the separating pad58and the paper feeding roller52, and the original is fed-out to the original feeding path70sequentially.

In the paper feed apparatus10comprising such the separation unit56, if the paper feeding roller52rotates at the time of paper feeding, when the separating pad58and the original or the paper feeding roller52rub, a minute vibration may occur on the separating pad58and the separating pad holder60. At this time, since the separating pad holder60is supported with the support shaft84as a fulcrum in a rockable manner, a minute vibration of the separating pad58and the separating pad holder60(hereinafter, called “minute vibration of separating pad58etc.”) occurs in a rocking direction of the separating pad holder60, that is, an abutting direction of the paper feeding roller52and the separating pad58. Especially, since a frictional resistance becomes high when the separating pad58and the paper feeding roller52rub directly, the minute vibration of separating pad58etc. is amplified, and therefore, an abutting state of the separating pad58to the paper feeding roller52becomes unstable, and accordingly, a possibility that a sound (vibration sound) may occur also becomes high.

Then, in this first embodiment, it is intended that by attaching the weight member62to the separating pad holder60in a loosely-fitted state, the minute vibration of separating pad58etc. is suppressed, thereby to reduce a noise. In addition, “loosely-fitting” or “loosely-fitted” means fitting of two members in a state where a play is secured, that is, a state where some gap is formed, and further means in a manner that one member can move apart from the other member.

Briefly describing, the separating pad holder60is provided with a loosely-fitting shaft that is a shape of short cylinder extending in a direction the same or approximately the same as a direction of the minute vibration of separating pad58etc., and two engaging portions are provided at a predetermined interval in an axial direction of the loosely-fitting shaft. On the other hand, the weight member62is formed with a loosely-fitting hole into which the loosely-fitting shaft of the separating pad holder60is inserted. In addition, a diameter of the loosely-fitting shaft of the separating pad holder60is set to be slightly smaller than a diameter of the loosely-fitting hole of the weight member62. Furthermore, a distance between the engaging portions of the separating pad holder60is set slightly larger than a thickness of the weight member62. Then, by fitting the loosely-fitting shaft and the loosely-fitting hole to each other between the two engaging portions, the weight member62is attached to the separating pad holder60in the loosely-fitted state, and therefore, it is brought into a state where the weight member62can move (minute-vibrate) to the axial direction of the loosely-fitting shaft.

In this first embodiment, the loosely-fitting shaft and the two engaging portions of the separating pad holder60are provided using shoulder bolts92. Specifically, two threaded holes that are aligned with each other at a predetermined interval in a direction orthogonally intersecting the original feeding direction are formed in the downstream side end of the arm portion80of the separating pad holder60so as to sandwich the spring attaching portion88. The two threaded holes are formed so as to extend a direction the same or approximately the same as the direction of the minute vibration of separating pad58, and opened downwardly. Then, the shoulder bolts92are screwed into these two threaded holes, respectively. The shoulder bolt92has a head portion92a, a base portion92bthat has a diameter smaller than that of the head portion92aand an outer periphery surface being not threaded, and a screw portion92cthat has a diameter smaller than that of the base portion92b. By tightening the shoulder bolts92into the threaded holes formed on the arm portion80till the last, the loosely-fitting shaft of a length according to an axial length of the base portion92bis formed so as to project from the arm portion80downward. That is, in this first embodiment, the base portions92bof the shoulder bolts92function as the loosely-fitting shafts, and the upper surface of the head portions92aof the shoulder bolts92and the lower surface of the arm portion80function as the two engaging portions.

On the other hand, the weight member62is formed of metal such as iron in a plate shape. This weight member62is formed with the loosely-fitting holes62afor being inserted with the base portions (loosely-fitting shafts)92bin positions corresponding to the base portions92bof the shoulder bolts92, respectively. The weight member62is attached to the separating pad holder60so as to couple the base portions92bto each other.

At this time, a diameter of the loosely-fitting hole62ais set to be slightly larger than the diameter of the base portion92b. Furthermore, a thickness of the weight member62is set to be slightly smaller than an axial length of the base portion92b, that is, a distance between the upper surface of the head portion92aof the shoulder bolt92and the lower surface of the arm portion80. Accordingly, when the weight member62is attached to the separating pad holder60, the weight member62will be in a loosely-fitted state, and a gap94is formed between the upper surface of the weight member62and the lower surface of the arm portion80. A size of this gap94, that is, a difference of a distance between the two engaging portions and the thickness of the weight member62is set as 0.1-0.3 millimeters, for example. Furthermore, a weight of the weight member62is set as 1 gram or more, for example.

When using such the separation unit56, even if the separating pad58etc. minute-vibrate at the time of paper feeding, the weight member62in the loosely-fitted state to the separating pad holder60moves out of synchronization with the separating pad holder60without following immediately due to inertia. Accordingly, since the weight member62gives a load of an opposite direction to the minute vibration of separating pad58etc., the minute vibration of separating pad58etc. can be reduced promptly. That is, since the weight member62minute-vibrates slightly out of synchronization with the minute vibration of separating pad58etc. without resonating with it, the minute vibration of separating pad58etc. is absorbed and thus attenuated promptly.

Furthermore, since a resonance point of the separating pad58etc. to the paper feeding roller52can be shifted by providing the weight member62to the separating pad holder60, the minute vibration of separating pad58etc. can be suppressed.

Furthermore, the minute vibration of separating pad58etc. can be suppressed only by providing the weight member62in the loosely-fitted state, and therefore, it is not necessary to make the separating pad58into a low frictional resistance or drop the abutting pressure (nip pressure) of the separating pad58to the paper feeding roller52in order to suppress the minute vibration of separating pad58etc., no fall occurs in the separation and feeding performance of the paper by the paper feeding roller52and the separating pad58.

In addition, although not limited in particular, it is preferable that an arranging position of the weight member62to the separating pad holder60is located in a position near the separating pad58than the support shaft84of the separating pad holder60in the original feeding direction, that is, in a position far from the support shaft84. It is because the minute vibration suppression effect by the weight member62is shown more largely by this.

As described above, according to this first embodiment, it is possible to adequately suppress the minute vibration of separating member58etc. and the sound accompanying the minute vibration while keeping the paper separation and feeding performance with simple structure of providing the weight member62in a loosely-fitted state to the separating pad holder60.

Next, with reference toFIG. 8andFIG. 9, a paper feed apparatus10that is the second embodiment of the present invention will be described. This second embodiment differs from the above-described first embodiment in a point of using a shaft member that is loosely fitted into a loosely-fitting hole as the weight member62. Since structure of remaining portions is the same or similar to that of the above-described first embodiment, a duplicate description will be omitted or simplified while applying the same reference numerals to the portions being common in the above-described first embodiment.

Briefly describing, in the second embodiment, a loosely-fitting hole that extends in the same or approximately the same direction as a direction of the minute vibration of separating pad58etc. is formed on the separating pad holder60. On the other hand, the weight member62is provided with loosely-fitting shaft that is inserted into the loosely-fitting hole of the separating pad holder60. On this loosely-fitting shaft, two engaging portions are provided at a predetermined interval in an axial direction. A diameter of the loosely-fitting shaft of the weight member62is set to be slightly smaller than a diameter of the loosely-fitting hole of the separating pad holder60. Furthermore, a distance between the engaging portions of the weight member62is set to be slightly longer than an axial length of the loosely-fitting hole of the separating pad holder60. Then, by fitting the loosely-fitting shaft and the loosely-fitting hole between the two engaging portions, the weight member62is attached to the separating pad holder60in a loosely-fitted state, and therefore, it is brought into a state where the weight member62can move (minute-vibrate) to the axial direction of the loosely-fitting hole. In addition, it is preferable that an arranging position of the weight member62to the separating pad holder60is located in a position near the separating pad58than the support shaft84of the separating pad holder60in an original feeding direction.

The weight member62is constituted by a bolt62band a nut62cin this second embodiment. The bolt62bhas a head portion and a shaft portion, and only a tip end portion of the shaft portion is threaded. Then, the nut62cis screwed to the tip end portion of this shaft portion. That is, in this second embodiment, the shaft portion of the bolt62bfunctions as a loosely-fitting shaft, and a lower surface of the head portion of the bolt62band an upper surface of the nut62cfunction as two engaging portions.

On the other hand, a single loosely-fitting hole80ais formed in a downstream side end of the arm portion80of the separating pad holder60in a center portion in a direction orthogonally intersecting the original feeding direction. At this time, a diameter of the loosely-fitting hole80ais set to be slightly larger than a diameter of the shaft portion of the bolt62b. Furthermore, an axial direction length of the loosely-fitting hole80ais set to be slightly shorter than a distance between the lower surface of the head portion of the bolt62band the upper surface of the nut62c. Accordingly, when the weight member62is attached to the separating pad holder60, the weight member62will be in a loosely-fitted state, and a gap94is formed between the lower surface of the arm portion80and the upper surface of the nut62c.

In also this second embodiment, as similar to the first embodiment, it is possible to adequately suppress the minute vibration of separating member58etc. and the sound accompanying the minute vibration while keeping the paper separation and feeding performance with simple structure of providing the weight member62in a loosely-fitted state to the separating pad holder60.

Next, with reference toFIG. 10andFIG. 11, a paper feed apparatus10that is the third embodiment of the present invention will be described. This third embodiment differs from the above-described first embodiment in a point of using a plurality of granular bodies as a weight member96. Since structure of remaining portions is the same or similar to that of the above-described first embodiment, a duplicate description will be omitted or simplified while applying the same reference numerals to the portions being common in the above-described first embodiment.

Briefly describing, in the third embodiment, metallic granular bodies such as iron powder will be used as the weight member96, and this weight member96is accommodated in an accommodating portion80bthat is formed on the arm portion80of the separating pad holder60. An opening of this accommodating portion80bis suitably sealed by a seal member98. At this time, the weight member96is brought into a state capable of moving in an inside of the accommodating portion80b(capable of minute-vibrating) by being accommodated in a state where there is a room leaving a part of an internal volume of the accommodating portion80b, that is, a state where there is a gap94. In addition, it is preferable that an arranging position of the weight member96to the separating pad holder60is located in a position near the separating pad58than the support shaft84of the separating pad holder60in an original feeding direction.

In also the third embodiment, even if the separating pad58etc. minute-vibrate at the time of paper feeding, since the weight member96moves out of synchronization with the separating pad holder60without following immediately due to inertia, the minute vibration of separating pad58etc. can be absorbed and attenuated promptly.

Accordingly, in the third embodiment, it is possible to adequately suppress the minute vibration of separating member58etc. and the sound accompanying the minute vibration while keeping the paper separation and feeding performance with simple structure of accommodating the weight member96within the accommodating portion80bof the separating pad holder60in a movable state.

In addition, in the above described third embodiment, although the weight member96is directly accommodated in the accommodating portion80bthat is formed on the separating pad holder60, not limited to this. For example, it is thinkable that the weight member96is sealed into a container in a state capable of moving, and the weight member96is embed in the separating pad holder60together with the container. Furthermore, the weight member96is not necessarily needed to be constituted by a plurality of granular bodies, and may be constituted as a single lump.

In addition, although the tabular separating pad58is used as a separating member in each of the above-described embodiments, the separating member may be a separating roller etc. formed in a shape of roller.

Furthermore, in each of the above-described embodiments, although the separating pad holder60is provided with the support shaft84that is provided in a position deviated from the separating pad58to the upstream side, the support shaft84may be provided in a position deviated from the separating pad58to the downstream side. Furthermore, the separating pad holder60is not necessarily needed to be made rockable (rotatable) with the support shaft84that is provided in a position that is deviated from the separating pad58to the upstream side or the downstream side as a fulcrum. For example, it is possible to provide the separating pad holder60in an opposite position to the paper feeding roller52such that the separating pad holder60can move reciprocately linearly against an abutting direction of the paper feeding roller52and the separating pad58.

Furthermore, although the paper feed apparatus10is applied to an automatic document feeder to feed a paper (original) that an image is to be read in each of the above-described embodiments, not limited to this. For example, the paper feed apparatus10is applicable also to a mechanism that feeds a paper (recording paper) on which an image is to be printed from a paper placing tray such as a manual paper feeding tray, a paper feeding cassette, etc. to the image forming portion24.

Furthermore, although the paper feed apparatus10is also applied to the multifunction machine (image forming apparatus)100that the main body12comprising the image forming portion24and the image reading apparatus14are integrated in each of the above-described embodiments, not limited to this. For example, the image reading apparatus14comprising the paper feed apparatus10may be made as an individual product. In this case, the image reading apparatus14is connected to a network and transmits an image having been read to a personal computer, another image forming apparatus, etc., for example.

In addition, the above-described specific numerals of sizes and shapes and the number of pieces of the weight members62and96, etc. are all mere example, and these are changeable according to necessity such as specification of product.