Patent Description:
For example, a device described in <CIT> (Detailed Descriptions and <FIG>) is known as this type of medium feeding device.

<CIT> (Detailed Descriptions and <FIG>) describes a sheet feeding device including a sheet feeding belt disposed above sheets set on a set board and having a suction hole, a suction device that sucks air from the sheet feeding belt to produce floating air to suck the set sheets, a discharging mechanism that discharges sheets by rotating the sheet feeding belt, an interval measuring unit that measures an interval between the sheets while the suction device sucks the sheets, and a controller that identifies the interval between the sheets based on an output from the interval measuring unit, and adjusts the airflow rate of the floating air based on the identified interval between the sheets.

Accordingly, it is an object of the present disclosure to further reduce, while performing a method of feeding media by floating and sucking the media one by one, sheet feeding failures by determining an operation of floating each medium than when feeding media with constantly unchanged parameters.

According to a first aspect of the present disclosure, there is provided a medium feeding device including a container member that accommodates sheet media, a discharging member located further than the media accommodated in the container member in a discharging direction in which the media are discharged to discharge the media one by one, a hand-over member disposed above the container member to suck the media accommodated in the container member with air and pass the media to the discharging member, a floating device disposed on a side of the media accommodated in the container member to blow air to an upper area of a side end surface of the media to float the media while an upper portion of the media is separated, a detector that detects a separation state of the medium floated by the floating device, and a controller that controls a medium-feeding operation including a pre-feeding blowing operation and a during-feeding blowing operation, the pre-feeding blowing operation serving as an air blowing operation performed by the floating device before the medium is fed, and the during-feeding blowing operation serving as an air blowing operation performed by the floating device from a start of feeding the medium to an end of feeding the medium, wherein while performing the pre-feeding blowing operation or the during-feeding blowing operation, the controller performs detection with the detector. On condition that a result of the detection fails to satisfy a preset target range, the controller changes a parameter for the medium-feeding operation including at least one of the pre-feeding blowing operation or the during-feeding blowing operation.

According to a second aspect of the present disclosure, there is a medium feeding device having the first aspect, wherein after the media are feedably accommodated in the container member and at a time point when a predetermined time elapses from a start of the pre-feeding blowing operation while the pre-feeding blowing operation is performed, the controller performs detection with the detector, and on condition that a result of the detection fails to satisfy the preset target range, the controller changes a parameter for the medium-feeding operation including at least the pre-feeding blowing operation.

According to a third aspect of the present disclosure, there is a medium feeding device having the second aspect wherein, on condition that the controller has changed the parameter after performing detection with the detector while the pre-feeding blowing operation is performed, the controller performs detection with the detector again on the pre-feeding blowing operation performed using the parameter previously changed while the pre-feeding blowing operation is performed after an elapse of predetermined time, and on condition that a result of the detection fails to satisfy the preset target range, the controller changes a parameter for the medium-feeding operation including at least the pre-feeding blowing operation.

According to a fourth aspect of the present disclosure, there is a medium feeding device having the first aspect wherein after the media are feedably accommodated in the container member and while the during-feeding blowing operation is performed, the controller performs detection with the detector at a predetermined time interval, and on condition that a result of the detection fails to satisfy the preset target range, the controller changes a parameter for the medium-feeding operation including at least the during-feeding blowing operation.

According to a fifth aspect of the present disclosure, there is a medium feeding device having the fourth aspect wherein, on condition that the controller has changed the parameter after performing detection with the detector while the during-feeding blowing operation is performed, the controller performs detection with the detector again on the during-feeding blowing operation performed using the parameter previously changed after an elapse of predetermined time, and on condition that a result of the detection fails to satisfy the preset target range, the controller changes a parameter for the medium-feeding operation including at least the during-feeding blowing operation.

According to a sixth aspect of the present disclosure, there is a medium feeding device having the first aspect wherein after the media are feedably accommodated in the container member and while the pre-feeding blowing operation and the during-feeding blowing operation are both performed, the controller performs detection with the detector, and on condition that a result of the detection fails to satisfy the preset target range, the controller changes a parameter for the medium-feeding operation including at least the pre-feeding blowing operation or the during-feeding blowing operation.

According to a seventh aspect of the present disclosure, there is a medium feeding device having the sixth aspect wherein, to perform detection with the detector first during a period when the during-feeding blowing operation is performed, on condition that the controller has changed the parameter after performing detection with the detector while the pre-feeding blowing operation is performed, the controller performs detection with the detector on the during-feeding blowing operation performed using the parameter changed in the pre-feeding blowing operation, and on condition that a result of the detection fails to satisfy the preset target range, the controller changes a parameter for the medium-feeding operation including at least the during-feeding blowing operation, and wherein to perform detection with the detector for second and subsequent times during a period when the during-feeding blowing operation is performed, on condition that the controller has changed the parameter after performing previous detection with the detector while the during-feeding blowing operation is performed, the controller performs detection with the detector again on the during-feeding blowing operation performed using the parameter previously changed after an elapse of predetermined time, and operation on condition that a result of the detection fails to satisfy the preset target range, the controller changes a parameter for the medium-feeding operation including at least the during-feeding blowing operation.

According to an eighth aspect of the present disclosure, there is a medium feeding device having the first aspect wherein the controller performs detection with the detector while the during-feeding blowing operation is performed immediately after the discharging member finishes an operation of transporting one of the media and before the hand-over member sucks a next one of the media.

According to a ninth aspect of the present disclosure, there is a medium feeding device having the first aspect wherein the controller determines, as a timing to change the parameter, a timing when intermittent operations performed intermittently during the medium-feeding operation are not performed while the during-feeding blowing operation is performed.

According to a tenth aspect of the present disclosure, there is a medium feeding device having the ninth aspect wherein the controller does not perform next detection with the detector on condition that the parameter determined to be changed based on a result of previous detection from the detector is left unchanged while the during-feeding blowing operation is performed.

According to an eleventh aspect of the present disclosure, there is a medium feeding device having the ninth aspect wherein the controller does not perform any of detection with the detector, a change of the parameter, and the detection and the change in a predetermined time period after the change of the parameter while the during-feeding blowing operation is performed.

According to the first aspect of the present disclosure, after repeating detection with the detector and a change of the parameter a predetermined number of times while the during-feeding blowing operation is performed, the controller performs detection with the detector, and the controller includes a limiter that limits, on condition that a result of the detection fails to satisfy the target range, a medium feeding operation to be performed after the operation of feeding a medium that is being fed is finished.

According to a twelfth aspect of the present disclosure, there is a medium feeding device having the first aspect wherein after repeating detection with the detector and a change of the parameter a predetermined number of times while the pre-feeding blowing operation is performed, the controller performs detection with the detector, and the controller includes a terminator that terminates, on condition that a result of the detection fails to satisfy the target range, the pre-feeding blowing operation.

A thirteenth aspect of the present disclosure is a medium feeding device having the first aspect including an air handling member that blows separation air to an upper medium and a medium located below the upper medium, the upper medium being floated by the floating device toward an end of the floated medium in a direction in which the medium is discharged, wherein the controller controls, as a control target, an air blowing operation of the air handling member in addition to the pre-feeding blowing operation and the during-feeding blowing operation performed by the floating device, and is capable of changing a parameter of the control target.

A fourteenth aspect of the present disclosure is a medium feeding device having the first aspect wherein the parameter for the medium-feeding operation includes at least one of an airflow rate, a direction of air, an area to which air is blown, an air temperature, an air suction rate, an initial uppermost position of the accommodated media, or a separation position of overlapping media.

The first aspect of the present disclosure is capable of further reducing failures in feeding media when the media are floated and sucked one by one to be fed, while the operation of floating the media is determined unlike in the case where the media are kept being fed at the same parameter.

The second aspect of the present disclosure is capable of preventing and reducing failures in feeding media during a pre-feeding blowing operation performed with a floating device while determining a floating operation of the media.

The third aspect of the present disclosure is capable of determining the floating operation of the media multiple times during the pre-feeding blowing operation performed with the floating device, and is capable of further reducing failures in feeding media than when determining the floating operation once.

The fourth aspect of the present disclosure is capable of reducing failures in feeding media during the during-feeding blowing operation performed with the floating device while determining the floating operation of the media.

The fifth aspect of the present disclosure is capable of determining the floating operation of the media multiple times during the during-feeding blowing operation performed with the floating device, and thus further reducing failures in feeding media.

The sixth aspect of the present disclosure is capable of determining the floating operation of the media in the pre-feeding blowing operation and the during-feeding blowing operation performed with the floating device, and is capable of further reducing failures in feeding media than when the floating operation of the media is not determined in the pre-feeding blowing operation.

The seventh aspect of the present disclosure is capable of effectively using check information of the floating operation of the media performed in the pre-feeding blowing operation during the during-feeding blowing operation performed with the floating device, and is capable of correcting the floating operation of the media as appropriate.

The eighth aspect of the present disclosure is capable of detecting a separation state of media floated by only the during-feeding blowing operation with the floating device without being affected by the medium feeding operation performed with the floating device.

The ninth aspect of the present disclosure is capable of preventing a change of the parameter during the intermittent operations performed intermittently during the during-feeding blowing operation with the floating device.

The tenth aspect of the present disclosure is capable of preventing a useless operation check by preceding a previous determination and restricting the following operation check when a parameter change performed by the controller takes time.

The eleventh aspect of the present disclosure is capable of stabilizing the effect of a parameter change without a useless operation check when the controller performs the parameter change.

The first aspect of the present disclosure is capable of preventing a failure in feeding media by restricting the operation of feeding media when detection on the during-feeding blowing operation repeated a specific number of times fails to satisfy the target range while the during-feeding blowing operation is performed.

The twelfth aspect of the present disclosure is capable of proceeding to the operation of feeding media by forcibly terminating the pre-feeding blowing operation when detection on the pre-feeding blowing operation repeated a specific number of times fails to satisfy the target range while the pre-feeding blowing operation is performed.

The thirteenth aspect of the present disclosure is capable of changing the parameter for the medium feeding operation performed with the floating device and an air handling member.

The fourteenth aspect of the present disclosure is capable of appropriately selecting the parameter for the medium feeding operation.

<FIG> is a rough diagram of a medium feeding device according to an exemplary embodiment of the present disclosure.

In <FIG>, the medium feeding device includes a container member <NUM> that accommodates sheet media S, a discharging member <NUM> that is disposed further than the media S accommodated in the container member <NUM> in a discharging direction in which the media S are discharged to discharge the media S one by one, a hand-over member <NUM> that is disposed above the container member <NUM>, sucks the media S (more specifically, a medium S1 located uppermost) accommodated in the container member <NUM> with air and passes the media S to the discharging member <NUM>, a floating device <NUM> that is disposed on a side of the media S accommodated in the container member <NUM>, that blows air to an upper area of a side end surface of the media to float the media S while an upper portion of the media S is separated, a detector <NUM> that detects a separation state of the media floated by the floating device <NUM>, and a controller <NUM> that controls a medium-feeding operation including a pre-feeding blowing operation BL0 serving as an air blowing operation performed by the floating device <NUM> before the media S are fed, and a during-feeding blowing operation BL1 serving as an air blowing operation performed by the floating device <NUM> from a start of feeding the media S to an end of feeding the media S. As illustrated in <FIG>, while performing the pre-feeding blowing operation BL0 or the during-feeding blowing operation BL1, the controller <NUM> performs detection with the detector <NUM>. When a result of the detection fails to satisfy a preset target range, the controller <NUM> changes a parameter for a medium-feeding operation including at least one of the pre-feeding blowing operation BL0 or the during-feeding blowing operation BL1.

The medium feeding device of this type is installed in a medium processing device including a processing member not illustrated that performs a predetermined process on the media S, and used as a device that embodies a function of feeding the media S to the processing member.

In this case, in addition to an image forming member that forms images on the media S, examples of the processing member include a device that performs various processing on media such as forming holes in media, cutting media, sorting media, or folding media.

In such as a technical member, the container member <NUM> generally includes a mount that receives the media S thereon, and the mount is usually supported by a hoist mechanism to be movable upward and downward. In an aspect of accommodating the media S of various different sizes, the container member <NUM> includes side guides and a rear guide.

Examples of the discharging member <NUM> include a wide range of members that discharge media, and a typical example of the discharging member <NUM> includes a pair of discharging rollers or a set of a discharging roller and a discharging belt.

Any member, such as a transport shuttle (a component of a vacuum head) or a transport belt, that sucks media one by one, passes the media to the discharging member <NUM>, and returns to the initial position may be appropriately selected as the hand-over member <NUM>.

Any member that blows air to the upper area of the accommodated media S from the side of the container member <NUM> (including from the front or rear side in a medium discharging direction besides from the side in a width direction crossing the medium discharging direction) may be selected as the floating device <NUM>.

Any member that images a side end surface of each medium such as a camera or sensor and that detects the separation state of the media S floated by the floating device <NUM> may be selected as the detector <NUM> as appropriate.

In addition, instead of an aspect of controlling the pre-feeding blowing operation BL0 before medium feeding and the during-feeding blowing operation BL1 during medium feeding, the controller <NUM> controls parameters for the medium-feeding operation including these operations BL0 and BL1 (including an air suction operation performed by the hand-over member <NUM>, and including, in an aspect including an air handling member <NUM> that blows air to separate an upper medium S1 that has floated toward the side end in a discharging direction of the floating medium S from a medium S located below the upper medium S1, an air blowing operation performed by the air handling member <NUM>, an operation of controlling the position of the uppermost one of the media S1 accommodated in the container member <NUM>, and a control operation for separating media transported in an overlapping manner). The controller <NUM> identifies the separation state of the media S that float during the pre-feeding blowing operation BL0 or the during-feeding blowing operation BL1, and changes, when the separation state of the media S deviates from a predetermined tolerance range, the parameters for the medium-feeding operation to change the medium-feeding operation conditions to more appropriate conditions.

Subsequently, a typical aspect or a preferable aspect of a medium feeding device according to an exemplary embodiment will be described.

First, as a typical aspect of the controller <NUM> that performs the pre-feeding blowing operation BL0, as illustrated in <FIG>, after the media S are feedably accommodated in the container member <NUM> (corresponding to "medium setting ST" in the drawing), the controller <NUM> performs detection with the detector <NUM> at a timing when predetermined time elapses from the start of the pre-feeding blowing operation BL0 and during the pre-feeding blowing operation BL0, and changes a parameter for a medium-feeding operation including at least the pre-feeding blowing operation BL0, on condition that a result of the detection fails to satisfy a preset target range.

In this example, on condition that the controller <NUM> has changed a parameter after performing detection with the detector <NUM>, while performing the pre-feeding blowing operation BL0 after an elapse of predetermined time, the controller <NUM> preferably performs detection with the detector again on the pre-feeding blowing operation BL0 performed using the previously changed parameter, and on condition that a result of the detection fails to satisfy a preset target range, the controller <NUM> preferably changes a parameter for the medium-feeding operation at least including the pre-feeding blowing operation BL0.

As a typical aspect of the controller <NUM> that performs the during-feeding blowing operation BL1, as illustrated in <FIG>, after the media S are feedably accommodated in the container member <NUM> and during the during-feeding blowing operation BL1, the controller <NUM> performs detection with the detector <NUM> at predetermined time intervals, and on condition that a result of the detection fails to satisfy a preset target range, the controller <NUM> changes a parameter for a medium-feeding operation including at least the during-feeding blowing operation BL1.

In this example, on condition that the controller <NUM> has changed a parameter after performing detection with the detector <NUM> while performing the during-feeding blowing operation BL1, the controller <NUM> preferably performs detection with the detector <NUM> again on the during-feeding blowing operation BL1 performed using the previously changed parameter after an elapse of predetermined time, and on condition that a result of the detection fails to satisfy a preset target range, the controller <NUM> preferably changes a parameter for the medium-feeding operation at least including the during-feeding blowing operation BL1.

In addition, in a typical aspect of the controller <NUM> that performs both the pre-feeding blowing operation BL0 and the during-feeding blowing operation BL1, as illustrated in <FIG>, after the media S are feedably accommodated in the container member <NUM>, the controller <NUM> performs detection with the detector <NUM> during both the pre-feeding blowing operation BL0 and the during-feeding blowing operation BL1, and on condition that a result of the detection fails to satisfy a preset target range, the controller <NUM> changes a parameter for a medium-feeding operation including at least one of the pre-feeding blowing operation BL0 or the during-feeding blowing operation BL1.

In this example, to perform detection with the detector <NUM> first while performing the during-feeding blowing operation BL1, on condition that the controller <NUM> has changed a parameter after performing detection with the detector <NUM> during the pre-feeding blowing operation BL0, the controller <NUM> preferably performs detection with the detector <NUM> on the during-feeding blowing operation BL1 performed using the parameter changed during the pre-feeding blowing operation BL0. On condition that a result of the detection fails to satisfy a preset target range, the controller <NUM> preferably changes a parameter for the medium-feeding operation at least including the during-feeding blowing operation BL1. To perform second or later detection with the detector <NUM> while performing the during-feeding blowing operation BL1, on condition that the controller <NUM> has changed a parameter after performing previous detection with the detector <NUM> while performing the during-feeding blowing operation BL1, the controller <NUM> preferably performs detection with the detector <NUM> again on the during-feeding blowing operation BL1 performed using the previously changed parameter after an elapse of predetermined time. On condition that a result of the detection fails to satisfy a preset target range, the controller <NUM> preferably changes a parameter for the medium-feeding operation at least including the during-feeding blowing operation BL1.

In a preferable aspect of the controller <NUM>, the controller <NUM> preferably performs detection with the detector <NUM> during the during-feeding blowing operation BL1 and in a period immediately after the discharging member <NUM> finishes delivering the medium S and before a next medium S adheres to the hand-over member <NUM>. In this example, the detector <NUM> performs detection on the floating state of the medium S depending only on the floating device <NUM>. This example is preferable in that the detection is not affected by the medium-feeding operation performed by any device other than the floating device <NUM>.

Examples of other preferable aspects of the controller <NUM> include an aspect where, when intermittent operations are intermittently performed during the medium-feeding operation while the during-feeding blowing operation BL1 is performed, a timing when the intermittent operations are not performed is set as a parameter change timing. In other words, in this example, parameters are not changed during the intermittent operations performed intermittently.

For example, as illustrated in <FIG>, assume an example case where detection is performed with the detector <NUM> during an operation of feeding a first medium S. In this case, examples of intermittent operations intermittently performed in the medium-feeding operation include an air suction operation performed by the hand-over member <NUM>, and an air blowing operation performed by the air handling member <NUM>. For these operations, parameters are changed at a timing when each intermittent operation is not performed (for example, in a non-operational time period in the medium-feeding operation or a time period between the operation of feeding a first medium S and the operation of feeding a second medium S).

As illustrated in <FIG>, the during-feeding blowing operation BL1 performed by the floating device <NUM> is not finished during the medium-feeding operation. As indicated with a solid line in <FIG>, when the during-feeding blowing operation BL1 is finished in a time period when the medium-feeding operation is finished, a parameter change for the floating device <NUM> may be performed. However, for example, when a job of feeding successive media S is instructed, to efficiently perform the medium-feeding operation, the during-feeding blowing operation BL1 is frequently successively performed without being stopped during the time period between the medium-feeding operations as illustrated in <FIG>. In such a case, the parameter change for the floating device <NUM> is performed after the during-feeding blowing operation is finished as indicated with a virtual line in <FIG>.

In this example, in a preferable aspect, to avoid useless detection with the detector <NUM>, the controller <NUM> does not perform next detection with the detector <NUM> while performing the during-feeding blowing operation BL1 on condition that a parameter change determined from a previous detection result from the detector <NUM> is not yet performed.

In another preferable aspect, to avoid useless detection and parameter change performed by the detector <NUM>, the controller <NUM> does not perform any of detection with the detector <NUM>, parameter change, and detection and parameter change for a predetermined time length after a parameter change while the during-feeding blowing operation BL1 is performed.

In a preferable aspect, the controller <NUM> performs detection with the detector <NUM> after repeatedly performing detection and a parameter change a specific number of times while performing the during-feeding blowing operation BL1, and includes a limiter that limits, on condition that a result of the detection fails to satisfy a target range, the operation of feeding subsequent media S after finishing the operation of feeding the currently fed medium S.

Examples of the "limiter" in this case include a form of stopping the operation of feeding the media S, a form of notifying that the operation of feeding the media S is out of a target range, and a form of repeating a determining operation until a result of the detection satisfies the target range after the operation of feeding the media S is temporarily stopped.

In another preferable aspect, the controller <NUM> performs detection with the detector <NUM> after repeating, a specific number of times, detection with the detector <NUM> and a parameter change while performing the pre-feeding blowing operation BL0, and includes a terminator that terminates the pre-feeding blowing operation on condition that a result of the detection fails to satisfy the target range.

When the "terminator" terminates the pre-feeding blowing operation, the termination may be notified to a user, or may directly shift to the during-feeding blowing operation, counting on the subsequent step.

As a typical aspect, to keep the interval between the media S within an appropriate range, the detector <NUM> detects the interval between, of all the media S that float in the detection area as a medium separation state, media vertically adjacent to each other to determine whether the interval is within a target range, for example, whether no interval is narrower than a predetermined range.

As another typical aspect, to keep the media S in a separation state instead of being piled, the detector <NUM> detects the thickness of the media S floating in the detection area, to determine whether the thickness is within a target range, for example, whether none of the media has a thickness exceeding a predetermined range.

Preferably, the target range is variably set depending on the information of type of media S. In this case, "the information of type of media S" includes, for example, a brand, a size, and a basis weight.

In another preferable aspect, the controller <NUM> controls an air suction operation performed by the hand-over member <NUM> in addition to the pre-feeding blowing operation BL0 and the during-feeding blowing operation BL1 performed by the floating device <NUM>, and is capable of changing the parameters to be controlled.

In another preferable aspect, the controller <NUM> includes the air handling member <NUM> that blows air to separate an upper medium S floated by the floating device <NUM> toward an end of the floating medium S in the discharging direction from a medium located below the upper medium S. The controller <NUM> controls an air blowing operation performed by the air handling member <NUM> in addition to the pre-feeding blowing operation BL0 and the during-feeding blowing operation BL1 performed by the floating device <NUM>, and is capable of changing the parameters to be controlled.

Parameters for the medium-feeding operation may be selected as appropriate, and typical examples of parameters include at least one of an airflow rate, a direction of air, an area to which air is blown, an air temperature, an air suction rate, an initial uppermost position of the accommodated media, or a separation position of overlapping media.

Hereinbelow, the present disclosure will be further described in detail based on exemplary embodiments illustrated in appended drawings.

<FIG> is a diagram of the entire structure of a medium processing device according to a first exemplary embodiment.

In <FIG>, a medium processing device <NUM> includes a medium feeding device <NUM> that feeds sheet media one by one, and a processing unit <NUM> that serves as a processing member that performs a predetermined process on the media fed from the medium feeding device <NUM>.

In the present example, the processing unit <NUM> includes an image forming unit <NUM> that forms images on the media. The image forming unit <NUM> employs various image forming methods such as an electrophotographic system or an inkjet printing method. The processing unit <NUM> includes an importing path <NUM> along which media fed from the medium feeding device <NUM> are transported to the image forming unit <NUM>, and an exporting path <NUM> along which media undergoing image formation at the image forming unit <NUM> are transported out of the processing unit <NUM>. In this example, the processing unit <NUM> separately includes a built-in medium feeder <NUM> below the image forming unit <NUM>. Media from the medium feeder <NUM> are also fed to the image forming unit <NUM> through a feed transport path <NUM>. Importing rollers <NUM> are disposed at the entrance of the importing path <NUM>. An appropriate number of transporting members are disposed at the importing path <NUM>, the exporting path <NUM>, and the feed transport path <NUM>.

In this example, as illustrated in <FIG>, the medium feeding device <NUM> includes a housing <NUM> that accommodates media. The housing <NUM> includes an upper drawer <NUM> and a lower drawer <NUM> vertically arranged in two stages to be drawable outward, and a manual feeder <NUM> disposed at an upper portion of the housing <NUM> to allow media to be manually fed therethrough. The medium feeding device <NUM> also includes a relay unit <NUM> on the side of the housing <NUM> closer to the processing unit <NUM>. The relay unit <NUM> relays media fed from the upper drawer <NUM>, the lower drawer <NUM>, and the manual feeder <NUM> to transport the media to the processing unit <NUM>.

In this example, both the upper drawer <NUM> and the lower drawer <NUM> accommodate a large number of media and feed the media one by one. The relay unit <NUM> includes a first transport path 17a along which the media fed from the upper drawer <NUM> are transported, a second transport path 17b along which the media fed from the lower drawer <NUM> are transported, and a third transport path 17c along which the media fed from the manual feeder <NUM> are transported. An appropriate number of transport rollers <NUM> are disposed at the first to third transport paths 17a to 17c. A merging transport path 17d that is continuous with an outlet port 17e leading to the processing unit <NUM> is disposed at the exit side of each of the first to third transport paths 17a to 17c. Discharge rollers <NUM> are disposed at the merging transport path 17d. The upper drawer <NUM> and the lower drawer <NUM> respectively include pulls 13a and 14a to be drawable to the near side.

In this example, the upper drawer <NUM> and the lower drawer <NUM> have substantially the same structure. Hereinbelow, the upper drawer <NUM> is described as an example.

In this example, as illustrated in, for example, <FIG>, the upper drawer <NUM> includes a container <NUM> serving as a container member that accommodates sheet media, discharging rollers <NUM> serving as a discharging member disposed further than the media accommodated in the container <NUM> in a discharging direction in which the media are discharged to discharge the media one by one, a vacuum head <NUM> disposed above the container <NUM> to serve as a hand-over member that sucks the media accommodated in the container <NUM> with air and passes the media to the discharging rollers <NUM>, a floating mechanism <NUM> that is disposed on a side in a direction crossing the discharging direction in which the media accommodated in the container <NUM> is discharged, the floating mechanism <NUM> serving as a floating device that blows air to the side of the media to float the media while separating the upper area of the media, an air handling mechanism <NUM> disposed further than the media accommodated in the container <NUM> in a discharging direction in which the media are discharged, the air handling mechanism <NUM> blowing air to separate an upper medium floated by the floating mechanism <NUM> from a medium located below the upper media, and a flotation detector <NUM> that detects a separation state of each medium floated by the floating mechanism <NUM>.

In this example, as illustrated in <FIG> and <FIG>, the container <NUM> includes a receiving bottom plate <NUM> that receives media of various sizes, side guides <NUM> (more specifically, 32a and 32b) disposed on the sides in a width direction crossing the discharging direction of media of various sizes placed on the receiving bottom plate <NUM> to serve as side guide members that fix and guide the side position of the media, an end guide <NUM> disposed at a rear side opposite to the side in the discharging direction in which the media loaded on the receiving bottom plate <NUM> are discharged to serve as a rear guide member that fixes and guides the rear position of the media, and a partitioning plate <NUM> that defines the position of the media loaded on the receiving bottom plate <NUM> in the discharging direction in which the media are discharged.

In this example, the container <NUM> may be designed in accordance with the size of media to be used. However, in view of high versatility, preferably, a normal-size medium is to be mainly used. In this case, examples of the normal-size medium include media with a length up to <NUM>. An example of media with such a size corresponds to media of A3 size or smaller in Japanese Industrial Standards (JIS).

In this example, examples of medium include, in addition to media with a uniform thickness, a medium with an uneven thickness such as an envelope that varies in thickness in the discharging direction.

In this example, the side guides <NUM> are movable in the width direction of the receiving bottom plate <NUM>, and fixed in a predetermined fixed position. The end guide <NUM> is movable in the discharging direction of the media on the receiving bottom plate <NUM>, and fixed in a predetermined fixed position. In this example, a separation plate <NUM> (refer to <FIG>) protrudes upward from the upper edge of the partitioning plate <NUM>. The separation plate <NUM> serves as a stopper wall that stops the upper area of a pile of the media located below the medium sucked by the vacuum head <NUM> with air.

As illustrated in <FIG>, the receiving bottom plate <NUM> is supported by a hoist mechanism <NUM> described below (refer to <FIG>) to be movable upward and downward.

In this example, as illustrated in <FIG>, <FIG>, the hoist mechanism <NUM> includes suspension portions <NUM> disposed at four portions of the receiving bottom plate <NUM> at both sides in the width direction crossing the medium discharging direction, and four wires <NUM> to <NUM> having the far ends coupled to the respective suspension portions <NUM>. After each of the wires <NUM> to <NUM> is wound around one or more guide pulleys <NUM>, a first end of each of the wires <NUM> to <NUM> is stuck to coaxially coupled take-up pulleys <NUM> (97a and 97b in this example), the take-up pulleys <NUM> are rotated by a driving motor <NUM> that is rotatable forward and backward, and the wires <NUM> to <NUM> are moved by a predetermined amount to raise or lower the receiving bottom plate <NUM> while keeping the receiving bottom plate <NUM> in a horizontal position.

A height sensor <NUM> sets the surface of one of the media loaded on the receiving bottom plate <NUM> to a predetermined medium reference height FC (refer to <FIG>).

The medium reference height FC in this case refers to a position where the uppermost position of the medium is set to be capable of undergoing an air suction operation from the vacuum head <NUM> on condition that the media S are accommodated in the container <NUM> in a substantially horizontal position.

In this example, as illustrated in <FIG> and <FIG>, the discharging rollers <NUM> include a driving roller <NUM> that drives to rotate, and a driven roller <NUM> that is driven to rotate following the rotation of the driving roller <NUM>. The discharging rollers <NUM> transport a medium while holding the medium at a contact portion between the driving roller <NUM> and the driven roller <NUM>.

In the present exemplary embodiment, as illustrated in <FIG>, a position sensor <NUM> is disposed downstream from the discharging rollers <NUM> in the medium discharging direction. This position sensor <NUM> detects the passage of a medium through a nip area of the discharging rollers <NUM>, and is disposed in a medium passage area. A detection signal from the position sensor <NUM> notifies the end of the operation of feeding a medium S transported previously, and serves as a trigger of the operation of feeding the subsequent medium S in a successive feeding mode.

In this example, as illustrated in <FIG>, <FIG>, and <FIG>, the vacuum head <NUM> is supported with a guide mechanism <NUM> (for example, a guide rod) by a head frame <NUM> fixed to the housing <NUM> above the container <NUM> to be movable forward and rearward in the medium discharging direction.

In this example, the vacuum head <NUM> includes a hollow box-shaped head body <NUM>. A surface of the head body <NUM> facing the media accommodated in the container <NUM> has a large number of vacuum holes <NUM>. The vacuum head <NUM> also includes a skirt portion 51a around the vacuum holes <NUM> in the head body <NUM> to keep the medium hermetic while sucking the medium with air.

A suction mechanism <NUM> is connected to the head body <NUM>. As illustrated in <FIG>, in this case, an example used as the suction mechanism <NUM> has a structure where a suction blower <NUM> and the head body <NUM> are connected with a connection duct <NUM>, an open-close valve <NUM> that opens and shuts the path is disposed at a portion of the connection duct <NUM>, and the open-close valve <NUM> is opened or shut by a valve motor <NUM>.

A forward/rearward moving mechanism <NUM> that moves the vacuum head <NUM> forward and rearward is disposed at the head frame <NUM>. In this example, as illustrated in <FIG> and <FIG>, the forward/rearward moving mechanism <NUM> fixes a stepping motor <NUM> to the head frame <NUM>, a driving pulley <NUM> is coupled to the stepping motor <NUM>, a predetermined number of transmission pulleys <NUM> are disposed at the head frame <NUM> at appropriate positions, a wire <NUM> is wound around the driving pulley <NUM> and the transmission pulleys <NUM>, and part of the wire <NUM> is stuck to the vacuum head <NUM>. In this example, the driving pulley <NUM> rotates in response to the forward or rearward rotation of the stepping motor <NUM>, the wire <NUM> moves by a predetermined distance in response, and the vacuum head <NUM> moves forward or rearward in the medium discharging direction.

In this example, as illustrated in <FIG>, <FIG>, <FIG>, and <FIG>, the floating mechanism <NUM> includes, for example, hollow box-shaped side guides <NUM> (32a and 32b). Each side guide <NUM> has multiple air outlets <NUM> at an upper portion facing the side of the media, and has, in the hollow portion, an air duct <NUM> having one end continuous with the corresponding air outlet <NUM> and the other end continuous with a blower <NUM> for blowing air. In this case, the blower <NUM> may be installed inside each side guide <NUM> or disposed outside of the side guide <NUM>.

An air suction duct <NUM> in which a heater <NUM> is installed is connected to the suction port of the blower <NUM>. The temperature inside the air suction duct <NUM> is detected by a temperature sensor <NUM>. The information from the temperature sensor <NUM> is taken into a control device <NUM>, and the heater <NUM> is controlled to be heated with a control signal from the control device <NUM>.

In this example, medium restrictors <NUM> are disposed near the air outlets <NUM> of the side guide <NUM>. The medium restrictors <NUM> in this example are disposed on the side of the media loaded on the receiving bottom plate <NUM>, and protrude to a medium accommodation area to restrict floating excess of media that float while using the floating mechanism <NUM>.

In this example, a shutter mechanism <NUM> that opens or shuts the air outlets <NUM> is disposed. As illustrated in <FIG>, <FIG>, the shutter mechanism <NUM> includes a planar shutter <NUM> covering the air outlet <NUM> and a shutter driving mechanism <NUM> that vertically moves the shutter <NUM> in a reciprocating manner. An example used as the shutter driving mechanism <NUM> in this case includes a driving motor <NUM> formed from a stepping motor, a driving transmission gear <NUM> coaxial with a driving shaft of the driving motor <NUM>, a shutter support member <NUM> that supports a lower portion of the shutter <NUM>, a rack <NUM> vertically extending at a side edge of the shutter support member <NUM>, and a driving transmission gear train <NUM> disposed between the rack <NUM> and the driving transmission gear <NUM> to engage the rack <NUM> and the driving transmission gear <NUM> with each other to transmit the driving force between the rack <NUM> and the driving transmission gear <NUM> via the driving transmission gear train <NUM>. Thus, the driving force from the driving motor <NUM> driven based on the driving signal from the control device <NUM> is transmitted to the shutter <NUM>.

Thus, in this example, each air outlet <NUM> is repeatedly opened and shut by the shutter mechanism <NUM>. Thus, air blown from the air outlets <NUM> is capable of easily floating the upper portion of the medium S in a fluctuation pattern.

In this example, as illustrated in <FIG>, the shutter mechanism <NUM> has a slit <NUM> in a portion of the shutter <NUM>. At an opening edge of the slit <NUM>, a predetermined inclined portion 78a is disposed to direct the direction of air blows blown from the air outlets <NUM> to obliquely below. Thus, this example is preferable in terms of the effect of separating the media S compared to a structure where the direction of all the air blows is substantially uniformly horizontal.

As illustrated in, for example, <FIG>, to change the inclination angle of the inclined portion 78a in the slit <NUM>, the inclined portion 78a in the slit <NUM> in the shutter <NUM> may be formed from a swingable louver <NUM> having its angle adjustable. In this case, the pattern of air blows blown from the air outlets <NUM> is changeable.

In this example, as illustrated in <FIG>, <FIG>, and <FIG>, the air handling mechanism <NUM> includes an air nozzle <NUM> that blows knife-shaped air to obliquely rearward from below to the end of the medium floated by the floating mechanism <NUM> in the discharging direction. An air guide plate <NUM> protrudes from a portion of the vacuum head <NUM> closer to the discharging rollers <NUM> to change the direction of air blown from the air nozzle <NUM>, and to separate the media by blowing air between the upper medium floated by the floating mechanism <NUM> and the media located below the upper medium.

In this example, the air nozzle <NUM> is continuous with an air duct <NUM>, to which an air blowing blower <NUM> is connected. Thus, at a portion of the air duct <NUM>, an open-close valve <NUM> that opens or shuts the flow path is disposed. The open-close valve <NUM> is opened or shut by a valve motor <NUM>. Thus, in this example, while the blower <NUM> is kept driving, air is blown from the air nozzle <NUM> in a switching manner by opening or shutting the open-close valve <NUM>.

In this example, as illustrated in <FIG> and <FIG> to 15D, the flotation detector <NUM> is disposed at an upper portion of each side guide <NUM>, and is formed from an imaging device such as a camera. The number of the flotation detector <NUM> may be at least one, and may be plural.

In this example, as illustrated in <FIG>, the flotation detector <NUM> detects the interval between the floating media S. When an interval g1 is larger than or equal to a predetermined threshold g0 (a level of the medium floating state at which the medium is preferably sucked by the vacuum head <NUM>), the flotation detector <NUM> determines the floating state of the media S as being preferable (good).

In contrast, as illustrated in <FIG>, when an interval g2 between any two of the media S is less than the threshold g0, the flotation detector <NUM> determines the floating state of the media S as being poor (no good).

In this example, when the interval between the floating media S is larger than or equal to the threshold g0, the flotation detector <NUM> determines the floating state of the media S as being preferable. Instead, depending on the type of medium (such as a thin paper sheet), a different upper limit threshold may be set to carefully handle the medium considering that the medium S is more likely to float in a poor floating state when the interval exceeds the upper limit threshold.

In the exemplary embodiment, the flotation detector <NUM> detects the interval between the floating media S, but this is not the only possible example. For example, the flotation detector <NUM> may detect the thickness of the floating media S. In this case, as illustrated in <FIG>, when the floating medium S has a thickness t1 of a predetermined threshold t0 (a specified thickness of a medium to be used is selected as the threshold) or smaller, the flotation detector <NUM> determines that the media S are appropriately separated without being piled together, and thus the flotation detector <NUM> determines the floating state of the media S as being preferable (good).

In contrast, as illustrated in <FIG>, when any of the floating media S has a thickness t2 exceeding the threshold t0, the flotation detector <NUM> determines that the multiple media S are possibly piled without being separated, and thus the flotation detector <NUM> determines the floating state of the media S as being poor (no good).

Naturally, both the interval of the media S and the thickness of the media S may be detected.

As illustrated in <FIG>, the present example includes the control device <NUM> that controls the medium feeding device <NUM>. The control device <NUM> is formed from a microcomputer including various processors. In the embodiments above, the term "processor" refers to a processor in a broad sense. Examples of the processor include general processors (for example, a central processing unit or CPU) and dedicated processors (for example, a graphics processing unit or GPU, an application specific integrated circuit or ASIC, a field programmable gate array or FPGA, and a programmable logic device).

This control device <NUM> captures, into the processors, various information resulting from, for example, job identification, or signals from various sensors (such as the position sensor <NUM>, the height sensor <NUM>, and the flotation detector <NUM>), executes various programs preinstalled into a memory not illustrated (including an improvement process program of the medium floating state (refer to <FIG>)), and transmits a predetermined control signal to each control target.

In this example, examples of the control target include the discharging rollers <NUM>, the vacuum head <NUM> (the suction mechanism <NUM>, and the forward/rearward moving mechanism <NUM>), the floating mechanism <NUM>, the air handling mechanism <NUM>, and the hoist mechanism <NUM>. The control device <NUM> includes a display <NUM> that displays the processing state of the medium feeding job or a warning indicating an abnormal state in medium feeding.

First, a basic medium feeding operation process of a medium feeding device according to an exemplary embodiment will be described with reference to <FIG>.

First, as illustrated in <FIG>, the floating mechanism <NUM> blows floating air from a side of a medium pile to float some upper sheets in the medium pile to the positions to be sucked by the vacuum head <NUM> with air.

In this state, as illustrated in <FIG>, the open-close valve <NUM> in the suction mechanism <NUM> in the vacuum head <NUM> is opened to cause the vacuum head <NUM> to form a negative pressure. Thus, the vacuum head <NUM> sucks the floating medium S1 located uppermost with air. At this time, the vacuum head <NUM> has a recessed portion between the surrounding skirt portion 51a and the surfaces of the vacuum holes <NUM> in the head body <NUM>. Thus, the medium S1 is deformed along the recessed portion, and the skirt portion 51a disposed to tightly close the negative pressure area is also raised together with the medium S1.

Thereafter, as illustrated in <FIG>, the open-close valve <NUM> in the air handling mechanism <NUM> is opened, air is applied to the air guide plate <NUM> located on the side of the vacuum head <NUM> facing in the discharging direction, to insert separating air between an uppermost medium S1 sucked by the vacuum head <NUM> with air and second and lower media S located below the uppermost medium S1, and the second and lower media S following the uppermost medium S are dropped down with air.

Thereafter, as illustrated in <FIG>, the vacuum head <NUM> holding the uppermost medium S1 moves forward toward the discharging rollers <NUM>, the vacuum head <NUM> passes the medium S1 to the discharging rollers <NUM>, and then the open-close valve <NUM> in the vacuum head <NUM> and the open-close valve <NUM> in the air handling mechanism <NUM> are shut.

Thereafter, as illustrated in <FIG>, the vacuum head <NUM> is returned to the initial position to be ready for the next medium feeding operation.

<FIG> is a timing chart of each device in the above medium feeding operation process.

In <FIG>, "a vacuum-head blower" corresponds to "the blower <NUM>" (refer to <FIG>) in the suction mechanism <NUM>, "an air-handling blower" corresponds to "the blower <NUM>" (refer to <FIG>) in the air handling mechanism <NUM>, and "a flotation blower" corresponds to "the blower <NUM>" (refer to <FIG>) in the floating mechanism <NUM>.

"A vacuum-valve motor" corresponds to the valve motor <NUM>, "an air-handling valve motor" corresponds to the valve motor <NUM>, and "a vacuum-head motor" corresponds to the stepping motor <NUM> in the forward/rearward moving mechanism <NUM>.

In this example, "the vacuum-head blower", "the air-handling blower", and "the flotation blower" are kept on during the medium feeding job. "The vacuum-valve motor", "the air-handling valve motor", and "the vacuum-head motor" repeat on/off control for each sheet medium to repeatedly perform suction and forward/rearward movement with the vacuum head <NUM> and feeding and stopping feeding of separation air from the air handling mechanism <NUM>.

In this example, the floating mechanism <NUM> performs the air blowing operation (pre-feeding blowing operation BL0) performed before the media S set in the container <NUM> are fed, and the air blowing operation (during-feeding blowing operation BL1) performed after the start of feeding the media S set in the container <NUM> until the end of feeding the media A.

Generally, the floating mechanism <NUM> floats the media S to suck the media S1 with the vacuum head <NUM> with air for feeding the media S.

In this example, in addition to the above-described during-feeding blowing operation, the floating mechanism <NUM> performs the above-described pre-feeding blowing operation to separate a pile of the media S set in the container <NUM> in advance, to preferably float the media S during medium feeding.

In this example, the container <NUM> raises a pile of the media S loaded on the receiving bottom plate <NUM> with the hoist mechanism <NUM> to align the uppermost position of the pile of the media S with the medium reference height FC. During the medium-feeding operation, the loaded media S are sequentially fed. Thus, the pile of the media S in the container <NUM> is raised by the hoist mechanism <NUM>, and the media S located below in the loaded pile of the media S arrive at a position where the media S are to be floated by the floating mechanism <NUM>, and float with an air blow from the floating mechanism <NUM>. At this time, an upper medium group in the loaded pile of the media S located in an upper area, and a lower medium group in the loaded pile located in a lower area differ in the characteristics such as the paper quality attributable to the humidity or dried state. Thus, the upper medium group and the lower medium group may have a floating state differing from the medium floating state of the previously fed medium S although a predetermined parameter is selected as a floating condition (such as airflow rate of a blow) of the floating mechanism <NUM>. In this manner, keeping the medium feeding operation with the same parameter may lead to an inappropriate separation state (paper jamming or overlapping transport) while the floating mechanism <NUM> is performing the operation of floating the media S.

In this example, the medium feeding device <NUM> may be desired to handle various different types of media. Different types of media, for example, a thin paper sheet and a thick paper sheet vary in the medium floating state. For example, when the parameters for the medium-feeding operation (for example, an airflow rate of the floating mechanism <NUM>, an air suction rate of the vacuum head <NUM>, and an air blow rate of the air handling mechanism <NUM>) are set to be suitable for the thick paper sheet, and, for example, when a thin paper sheet is used instead of a thick paper sheet, the parameters for the medium-feeding operation may be inappropriate for the thin paper sheet. In such a case, for example, although a thick paper sheet is floated in a preferable floating state by the floating mechanism <NUM>, a thin paper sheet may be floated in a poor floating state by the floating mechanism <NUM>, and thus may be, for example, unstably sucked and held by the vacuum head <NUM>. Thus, such a parameter setting may interfere with the medium-feeding operation.

Thus, the present exemplary embodiment employs a control method including determining the medium floating state, and, when the medium floating state is inappropriate, changing the parameters for the medium-feeding operation to improve the medium-feeding operation.

In this case, the process of determining the medium floating state is performed in both the pre-feeding blowing operation BL0 and the during-feeding blowing operation BL1.

<FIG> are flowcharts of the process of improving the medium-feeding operation according to the present exemplary embodiment.

First, in this example, as illustrated in <FIG>, the process of improving the medium-feeding operation is performed accompanying the pre-feeding blowing operation BL0. In this example, the pre-feeding blowing operation BL0 may be performed only once, or may be performed multiple times at each predetermined time interval (refer to <FIG>).

More specifically, the floating mechanism <NUM> (the air outlets <NUM> and the shutter mechanism <NUM>) performs an air blow as the pre-feeding blowing operation BL0.

In addition, the vacuum head <NUM> repeatedly performs an operation of sucking air and stopping sucking air multiple times. This operation of the vacuum head <NUM> of sucking air and stopping sucking air is a dummy operation, but is preferable because this operation repeatedly raises or drops upper media, and provides a disturbance to the medium orientation to facilitate separation of the media with a blow.

Thereafter, the flotation detector <NUM> performs detection (detects an interval between sheets serving as media in this example) after an elapse of predetermined time, and determines whether a result of the detection falls within a determined target range.

In this case, when a result of the detection of the flotation detector <NUM> exceeds the target range (refer to <FIG>), the flotation detector <NUM> determines that the floating state of the sheet serving as the medium is poor. When a result of the detection of the flotation detector <NUM> falls within the target range (refer to <FIG>), the flotation detector <NUM> determines that the floating state of the sheet serving as the medium is preferable.

As described above, when a result of the detection of the flotation detector <NUM> is out of the target range, the parameter for the medium-feeding operation (corresponding to "the sheet feeding operation") including the pre-feeding blowing operation BL0, or in this example, a parameter PM1 (refer to <FIG>) for the air blowing operation performed by the floating mechanism <NUM> is changed.

In this example, an air blow rate from the air outlets <NUM> selected as an example of the parameter PM1 is changed to be increased because the floating state is determined as being poor due to a narrow interval between the sheets serving as the media.

Instead of the air blow rate, the parameter PM1 may be selected as appropriate from any conditions that affect the operation of floating the media with the floating mechanism <NUM>, for example, the air temperature, an air blowing direction, or an air blowing pattern.

In this case, to change the air temperature, the heating condition of the heater <NUM> may be changed. To change the air blowing direction or the blowing pattern, the pattern or time of opening or shutting the shutter <NUM>, or the inclination direction of the slit <NUM> in the shutter <NUM> may be changed.

As illustrated in <FIG>, the parameter PM1 may be changed at a timing when the pre-feeding blowing operation BL0 is not performed, and the changed parameter PM1 is applied to the next pre-feeding blowing operation BL0.

When the next pre-feeding blowing operation BL0 is not performed, the changed parameter PM1 is applied to the during-feeding blowing operation BL1 performed first in the medium-feeding operation.

When the pre-feeding blowing operation BL0 is performed multiple times, and the parameter is changed more than or equal to a predetermined number of times N, the operation mode of the medium feeding device <NUM> is selected. When a stop operation mode is selected, the entire device is stopped, and the display <NUM> (refer to <FIG>) displays a warning.

On the other hand, when a non-stop mode is selected as the operation mode, as illustrated in <FIG>, the floating mechanism <NUM> finishes blowing air, and the shutter mechanism <NUM> finishes the opening and shutting operation. This operation is performed to check the medium floating state again during the medium-feeding operation although an appropriate parameter change is not performed during the pre-feeding blowing operation.

When a result of the detection of the flotation detector <NUM> is within a target range, no parameter change is performed in particular, and as illustrated in <FIG>, the floating mechanism <NUM> finishes blowing air, and the shutter mechanism <NUM> finishes the opening and shutting operation.

In this example, as illustrated in <FIG>, a process of improving the medium-feeding operation (sheet feeding operation) is performed accompanying the during-feeding blowing operation BL1. In this example, the during-feeding blowing operation BL1 is performed every time when the medium-feeding operation is performed (refer to <FIG>).

In <FIG>, when an instruction to start feeding sheets serving as media is received, the floating mechanism <NUM> starts blowing air, and the shutter mechanism <NUM> starts the opening and shutting operation.

Thereafter, the vacuum head <NUM> sucks the sheets serving as media, the air handling mechanism <NUM> starts blowing air, and the vacuum head <NUM> transports the sucked sheets serving as media toward the discharging rollers <NUM>.

Thereafter, whether the timing for the flotation detector <NUM> to perform detection has come is determined. When the timing for the flotation detector <NUM> to perform detection has not come yet, the medium-feeding operation is repeated until the number of sheets fed arrives at the prescribed number of sheets.

When the timing for the flotation detector <NUM> to perform detection has come, as illustrated in <FIG>, the flotation detector <NUM> measures the interval between the sheets serving as media to determine whether the interval is within the determined target range.

Thereafter, when the number of times the parameter is changed sequentially fails to arrive at the predetermined prescribed number of times (M times), the parameter is changed (the parameter PM1 is changed in this example) on condition that the parameter is out of the target range (refer to <FIG>).

In this example, for example, when a job of feeding one sheet is specified, the during-feeding blowing operation BL1 is not finished during the sheet feeding operation. After an elapse of predetermined time after the feeding operation is finished, the during-feeding blowing operation BL1 is temporarily finished. In this manner, the shutter mechanism <NUM> and the blower <NUM> in the floating mechanism <NUM> are controlled to be turned on or off for each sheet feeding job.

However, in this example, when, for example, a job of feeding sequential sheets (n sheets) is specified, the floating mechanism <NUM> successively performs the during-feeding blowing operation BL1 also during intermittent sheet feeding operations (an operation of feeding a first sheet, an operation of feeding a second sheet,. , and an operation of feeding an n-th sheet). Specifically, the job of feeding successive sheets is controlled in such a manner that a time period after one sheet feeding operation is finished and before the floating mechanism <NUM> is turned off (after-blow time) is set long, and when the next sheet feeding operation is started before the floating mechanism <NUM> is turned off, turning off the air blowing operation of the floating mechanism <NUM> is cancelled. Thus, the floating mechanism <NUM> successively performs the during-feeding blowing operation BL1, and the floating mechanism <NUM> stably performs the operation of floating the media during the job of feeding successive sheets.

Thus, in this example, as illustrated in <FIG>, for both the job of feeding one sheet each and the job of feeding successive sheets, the floating mechanism <NUM> changes the parameter PM1 when the floating mechanism <NUM> is not performing the during-feeding blowing operation BL1.

Regardless of when a control method of temporarily finishing the during-feeding blowing operation BL1 in a time period between feeding operations in a job of feeding successive sheets is employed, the floating mechanism <NUM> may naturally change the parameter PM1 in the time period between the feeding operations.

As illustrated in <FIG>, the changed parameter is used in the next during-feeding blowing operation BL1.

When a result of the detection of the flotation detector <NUM> is within the determined target range, the process returns to C in <FIG>, and the medium-feeding operation is performed until the number of sheets fed arrives at the prescribed number of sheets.

In <FIG>, when the parameter change successively arrives at the prescribed number of times (M times), the sheet feeding operation is temporarily stopped when the medium-feeding operation (sheet feeding operation) in progress is finished. However, the floating mechanism <NUM> keeps the operation of blowing air.

Thereafter, the flotation detector <NUM> measures the interval between the sheets serving as media, and determines whether the interval is within the determined target range. When the interval is within the determined target range, the flotation detector <NUM> restarts the sheet feeding operation, and then, as illustrated in <FIG>, performs the sheet feeding operation until the number of sheets fed arrives at the prescribed number of sheets.

When a result of the detection of the flotation detector <NUM> fails to fall within the determined target range, the parameter change is performed on condition that the number of times the parameter is changed has not arrived at the prescribed number of times (N times).

In contrast, when the parameter change is performed more than or equal to N times, the entire device is stopped and the display <NUM> (refer to <FIG>) displays a warning. Second Exemplary Embodiment.

<FIG> illustrates a related portion of a medium feeding device according to the second exemplary embodiment.

In <FIG>, the medium feeding device <NUM> has a basic structure substantially the same as that of the first exemplary embodiment, but differs from the first exemplary embodiment in parameters for the medium-feeding operation that are to be changed when a result of the detection of the flotation detector <NUM> deviates from the predetermined target range.

In this example, in addition to the parameter (PM1) for the air blowing operation performed by the floating mechanism <NUM>, a parameter (PM2) for the air suction operation performed by the vacuum head <NUM> and a parameter (PM3) for the air blowing operation performed by the air handling mechanism <NUM> are to be changed.

In this example, the air suction operation performed by the vacuum head <NUM> and the air blowing operation performed by the air handling mechanism <NUM> are intermittently performed for each medium-feeding operation (corresponding to "the sheet feeding operation" in <FIG>). Thus, as illustrated in, for example, <FIG>, the parameters PM2 and PM3 for these operations are changed when the medium-feeding operation is not intermittently performed (for example, in a time period during the medium-feeding operation not intermittently performed or in the time period between the medium-feeding operations).

In this example, the parameter PM1 of the floating mechanism <NUM> is similar to that in the first exemplary embodiment.

Examples of the parameter PM2 of the vacuum head <NUM> include an air suction rate of the vacuum head <NUM>.

In this case, for example, as illustrated in <FIG>, the degree of opening of the open-close valve <NUM> in the suction mechanism <NUM> in the vacuum head <NUM> is adjustable successively or stepwise, and the degree of opening of the open-close valve <NUM> is changeable with the valve motor <NUM>.

For example, when the medium is floated by the floating mechanism <NUM> in a poor floating state, the air suction rate may be increased to enhance the suction force of the vacuum head <NUM> to suck the medium.

As another example of changing the air suction rate of the vacuum head <NUM>, the open-close valve <NUM> may be opened or shut by being turned on or off to change the number of rotations of the blower <NUM>.

Other examples of the parameter PM2 include the time length for which and the start timing at which the vacuum head <NUM> performs air suction.

Examples of the parameter PM3 of the air handling mechanism <NUM> include an air blow rate from the air nozzle <NUM>, an air blow area, and an air blowing direction.

In this case, as illustrated in, for example, <FIG>, "the air blow rate" from the air nozzle <NUM> is changeable by changing, with the valve motor <NUM>, the degree of opening of the open-close valve <NUM> in the air handling mechanism <NUM> that is adjustable successively or stepwise.

For example, when the media are selectively used between the thick paper sheets and the thin paper sheets, changing the air blow rate from the air nozzle <NUM> in accordance with the type of media is effective.

As another example of changing the air blow rate, the open-close valve <NUM> may be opened or shut by being turned on or off to change the number of rotations of the blower <NUM>.

As illustrated in, for example, <FIG>, "the air blow area" may be changed by arranging one or more sets of multiple (three in this example) air handling mechanisms <NUM> (more specifically, 80a to 80c) to orient the respective blow areas toward a blown area Sw of the medium S.

In addition, for example, as illustrated in <FIG>, "the air blowing direction" or an air blowing direction θ (an angle with respect to the horizon) from the air nozzle <NUM> is changeable by swingably disposing a louver <NUM> for restricting the air direction in, for example, the air nozzle <NUM>, and changing the direction of the louver <NUM> that is drivable by an actuator <NUM> such as a solenoid.

As illustrated in <FIG>, another example for changing "the air blow direction" is to connect, to the air duct <NUM>, two air nozzles <NUM> (more specifically, 81a and 81b) that blow air in different directions, disposing a switching valve <NUM> at a connection portion of the air duct <NUM> continuous to the two air nozzles <NUM> (81a and 81b), switching this switching valve <NUM> to be securely connected to either one of the air nozzles <NUM> (81a and 81b) to select the air nozzle <NUM> (81a or 81b) in a switching manner.

In the present exemplary embodiment, in the parameter change, three parameters PM1 to PM3 are changed, but this is not the only possible example. For example, two parameters PM1 and PM2, two parameters PM1 and PM3, or two parameters PM2 and PM3 may be changed, or, only the parameter PM2 or PM3 may be changed instead of the parameter PM1.

<FIG> illustrates a related portion of a medium feeding device according to a third exemplary embodiment.

In <FIG>, the medium feeding device <NUM> has substantially the same basic structure as the first and second exemplary embodiments, but differs from the first and second exemplary embodiments in the parameters for the medium-feeding operation to be changed when a result of the detection of the flotation detector <NUM> deviates from the predetermined target range.

In this example, in addition to the parameters (PM1, PM2, and PM3) to be changed in the second exemplary embodiment, a parameter (PM4, corresponding to the medium reference height FC) for the height position of the pile of the media S loaded on the container <NUM>, and a parameter (PM5) for the upper end position of the separation plate <NUM> are selected.

In this example, the height adjustment of the pile of the media S loaded on the container <NUM> and the adjustment of the vertical position of the separation plate <NUM> are intermittently performed for each medium-feeding operation (corresponding to "the sheet feeding operation" in <FIG>). Thus, as illustrated in, for example, <FIG>, the parameters PM4 and PM5 for these operations are changed at a timing when the medium-feeding operation is not intermittently performed (for example, in the time period during the medium-feeding operation not intermittently performed or in the time period between the medium-feeding operations).

In this example, as illustrated in <FIG>, the medium feeding device <NUM> appropriately raises or lowers the receiving bottom plate <NUM> with the hoist mechanism <NUM> to change the uppermost position of the pile of the media S loaded on the receiving bottom plate <NUM>, that is, the height position of the pile of the media S.

In this case, the height position of the pile of the media S is normally adjusted to correspond to the medium reference height FC. However, when the height position of the pile of the media S facing the air outlets <NUM> of the floating mechanism <NUM> is changed, the number of media accommodated in the area facing the air outlets <NUM> is changed, and thus the number of media separated by the air blown from the air outlets <NUM> is changed. Thus, the floating state of the media S is changed.

In this example, the flotation detector <NUM> performs detection (measures the interval between the sheets serving as media), and determines whether a result of the detection is within a predetermined target range.

In this example, the target range indicates the range between the upper-limit threshold and the lower-limit threshold. For example, in an assumption that the interval between the sheets serving as media in the floating state is larger than the target range, as illustrated in <FIG>, the position of the receiving bottom plate <NUM> may be raised to raise the height position of the pile of the media to change the parameter PM4.

At this time, the sheets are separated by a surplus distance. Thus, as illustrated in <FIG>, when the number of sheets facing the air outlets <NUM> is increased, the number of sheets that receive an air blow is increased, and the number of sheets to be floated and separated is thus increased.

In contrast, when the interval between the sheets serving as media is smaller than the target range, the sheets may be transported while overlapping each other. Thus, as illustrated in <FIG>, the position of the receiving bottom plate <NUM> may be lowered to lower the height position of the pile of the media to change the parameter PM4.

In this case, as illustrated in <FIG>, decreasing the number of sheets facing the air outlets <NUM> allows reduction of the number of sheets receiving an air blow, and reduction of the number of sheets to be floated and separated.

In this example, as illustrated in <FIG>, <FIG>, the medium feeding device <NUM> includes the separation plate <NUM> in front of a contact area (nip area) of the discharging rollers <NUM>. As illustrated in <FIG>, the separation plate <NUM> prevents overlapping transport, or a phenomenon where a sheet S1 transported while being sucked and held by the vacuum head <NUM> and a sheet S2 located below the sheet S1 are transported together.

In this case, as illustrated in <FIG>, when the upper end position of the separation plate <NUM> is low, the overlapping transport is highly likely to occur. In contrast, when the upper end position of the separation plate <NUM> is high, the sheet to be fed is more likely to cause collision and paper jamming.

In this example, as illustrated in <FIG>, the separation plate <NUM> is supported by a position changing mechanism <NUM>. This position changing mechanism <NUM> is formed from, for example, an actuator that moves in the vertical direction to change the vertical position of the separation plate <NUM>.

Also in this example, the flotation detector <NUM> performs detection (measures the interval between the sheets serving as media), and determines whether a result of the detection falls within the predetermined target range.

In this example, the target range indicates the range between the upper-limit threshold and the lower-limit threshold. For example, when the interval between the sheets serving as media in the floating state is smaller than the target range, the upper end position of the separation plate <NUM> may be raised to change the parameter PM5 as illustrated in <FIG>.

In this case, the lower sheet S2 highly likely to cause overlapping transport is easily blocked.

In contrast, when the interval between the sheets serving as media in the floating state is larger than the target range, the upper end position of the separation plate <NUM> may be lowered to change the parameter PM5 as illustrated in <FIG>.

At this time, the lower sheet S2 is more easily blocked. Thus, the sheet S1 that is to be provided may be allowed to flow more easily to less easily cause paper jamming.

In the present exemplary embodiment, the five parameters PM1 to PM5 are changed in the parameter change, but this is not the only possible example. Two, three, or four parameters including the parameter PM4 or PM5 may be changed. Instead, only the parameter PM4 or PM5 may be changed.

Claim 1:
A medium feeding device, comprising:
a container member (<NUM>) that accommodates sheet media (S) ;
a discharging member (<NUM>) located further than the media (S) accommodated in the container member (<NUM>) in a discharging direction in which the media (S) are discharged, to discharge the media (S) one by one;
a hand-over member (<NUM>) disposed above the container member (<NUM>) to suck the media (S) accommodated in the container member (<NUM>) with air and pass the media (S) to the discharging member (<NUM>);
a floating device (<NUM>) disposed on a side of the media (S) accommodated in the container member (<NUM>) to blow air to an upper area of a side end surface of the media (S) to float the media (S) while an upper portion of the media (S) is separated;
a detector (<NUM>) that detects a separation state of the medium (S) floated by the floating device (<NUM>); and
a controller (<NUM>) that controls a medium-feeding operation including a pre-feeding blowing operation (BL0) and a during-feeding blowing operation (BL1), the pre-feeding blowing operation (BL0) serving as an air blowing operation performed by the floating device (<NUM>) before the medium (S) is fed, and the during-feeding blowing operation (BL1) serving as an air blowing operation performed by the floating device (<NUM>) from a start of feeding the medium (S) to an end of feeding the medium (S),
wherein while performing the pre-feeding blowing operation (BL0) or the during-feeding blowing operation (BL1), the controller (<NUM>) performs detection with the detector (<NUM>), and on condition that a result of the detection fails to satisfy a preset target range, the controller changes a parameter for the medium-feeding operation including at least one of the pre-feeding blowing operation (BL0) or the during-feeding blowing operation (BL1),
the medium feeding device characterised in that after repeating detection with the detector (<NUM>) and a change of the parameter a predetermined number of times while the during-feeding blowing operation (BL1) is performed, the controller (<NUM>) performs detection with the detector (<NUM>), and
the controller (<NUM>) includes a limiter that limits, on condition that a result of the detection fails to satisfy the target range, a medium feeding operation to be performed after the operation of feeding a medium (S) that is being fed is finished.