MEDIA CONVEYING APPARATUS, MEDIA CONVEYING METHOD, AND NON-TRANSITORY RECORDING MEDIUM

BACKGROUND

The present disclosure relates to a media conveying apparatus, a media conveying method, and a non-transitory recording medium.

For media conveying apparatuses such as scanners that convey and image media, an alignment function has been developed to correct the inclination of a conveyed medium. Specifically, the alignment function is to rotate a conveyance roller, which is used to convey media, for a predetermined period of time in a direction in which the medium is reversed and align the leading end of the medium.

An automatic document feeder (ADF) unit that separates a fed document by applying conveyance resistance to the document using a separation roller and then conveys the document to a document reading position is known. The ADF unit is provided with a load torque generating mechanism to apply a load torque as the conveyance resistance to the separation roller. The load torque generating mechanism can change the magnitude of the load torque. The ADF unit changes the load torque generated by the load torque generating mechanism from a first value at the start of sheet feeding to a smaller second value after the leading end of the fed document passing through a registration nip on the downstream from the separation roller and before the leading end of the fed document reaches the document reading position.

SUMMARY

In one aspect, a media conveying apparatus includes a feed roller to feed a medium, a separation roller located facing the feed roller, a conveyance roller located downstream from the feed roller in a media conveyance direction to convey the medium by rotating in a first direction and to align a leading end of the medium by stopping or rotating in a second direction opposite to the first direction, and circuitry configured to set a torque applied to the separation roller. The circuitry sets the torque applied to the separation roller after the conveyance roller starts to align the leading end of the medium to a value smaller than the torque applied to the separation roller before the conveyance roller starts to align the leading end of the medium.

In another aspect, a media conveying method includes feeding a medium by a feed roller, conveying the medium by a conveyance roller located downstream from the feed roller in a media conveyance direction rotating in a first direction and aligning a leading end of the medium by the conveyance roller stopping or rotating in a second direction opposite to the first direction, and setting a torque applied to a separation roller located facing the feed roller. The setting includes setting the torque applied to the separation roller after the conveyance roller starts to align the leading end of the medium to a value smaller than the torque applied to the separation roller before the conveyance roller starts to align the leading end of the medium.

In another aspect, a non-transitory recording medium stores a plurality of instructions which, when executed by one or more processors of a media conveying apparatus, causes the one or more processors to perform a method. The method includes feeding a medium by a feed roller, conveying the medium by a conveyance roller located downstream from the feed roller in a media conveyance direction rotating in a first direction and aligning a leading end of the medium by the conveyance roller stopping or rotating in a second direction opposite to the first direction, and setting a torque applied to a separation roller located facing the feed roller. The setting includes setting the torque applied to the separation roller after the conveyance roller starts to align the leading end of the medium to a value smaller than the torque applied to the separation roller before the conveyance roller starts to align the leading end of the medium.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of embodiments of the present disclosure and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view of a media conveying apparatus according to an embodiment;

FIG. 2 is a diagram illustrating a conveyance passage inside the media conveying apparatus of FIG. 1;

FIG. 3 is a block diagram schematically illustrating a configuration of the media conveying apparatus of FIG. 1;

FIG. 4 is a block diagram schematically illustrating a configuration of a storage device and a processing circuit of the media conveying apparatus of FIG. 1;

FIG. 5 is a flowchart illustrating an example of a media reading process;

FIG. 6 is a continuation of the flowchart of FIG. 5;

FIG. 7 is a graph illustrating changes in the speed of a first conveyance roller and other rollers;

FIG. 8 is a schematic diagram illustrating the alignment of the leading end of a medium;

FIG. 9 is a flowchart illustrating another example of a part of the media reading process; and

FIG. 10 is a block diagram schematically illustrating a configuration of a processing circuit according to another embodiment.

The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. Also, identical or similar reference numerals designate identical or similar components throughout the several views.

DETAILED DESCRIPTION

In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result.

Referring now to the drawings, embodiments of the present disclosure are described below. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The objects and advantages of the present invention are recognized and achieved by the elements particularly pointed out in the appended claims and the combinations thereof. It is to be understood that both the above-described general description and the detailed description described below are exemplary and explanatory only and are not intended to restrict the claimed invention.

A media conveying apparatus, a media conveying method, and a control program according to an aspect of the present disclosure are described below with reference to the drawings. However, the technical scope of the present disclosure is not limited to the embodiments described below but includes the scope of the appended claims and the equivalents thereof.

FIG. 1 is a perspective view of a media conveying apparatus 100 as an image scanner. The media conveying apparatus 100 conveys media that are documents and images the media. Examples of the media include sheets of plain paper, sheets of thin paper, sheets of thick paper, cards, and booklets. The media conveying apparatus 100 may be, for example, a facsimile machine, a copier, or a multifunction peripheral (MFP). The media to be conveyed may be printing material (e.g., paper sheets) instead of documents. In this case, the media conveying apparatus 100 may be, for example, a printer.

The media conveying apparatus 100 includes a lower housing 101, an upper housing 102, a media tray 103, an ejection tray 104, an operation device 105, and a display device 106. In FIG. 1, Arrow A1 indicates the direction in which media are conveyed (may be referred to as a “media conveyance direction A1” in the following description). Arrow A2 indicates the width direction of the media conveying apparatus 100 (may be referred to as a “width direction A2” in the following description) perpendicular to the media conveyance direction A1. Arrow A3 indicates the height direction perpendicular to a media conveyance passage. In the following description, the term “upstream” refers to upstream in the media conveyance direction A1, and the term “downstream” refers to downstream in the media conveyance direction A1.

The upper housing 102 is located at a position covering the upper face of the media conveying apparatus 100, and is engaged with the lower housing 101 via a hinge such that the upper housing 102 can be opened and closed to for example remove a jammed medium or clean the inside of the media conveying apparatus 100.

The media tray 103 is engaged with the lower housing 101. Media to be fed and conveyed are placed on the media tray 103. The ejection tray 104 is engaged with the upper housing 102 and stacks ejected media. The ejection tray 104 may be engaged with the lower housing 101.

The operation device 105 includes an input device such as keys and an interface circuit that acquires signals from the input device. The operation device 105 receives an input operation performed by a user and outputs an operation signal corresponding to the input operation. The display device 106 includes a display and an interface circuit that outputs image data to the display, and displays image data on the display. Examples of the display include a liquid crystal display and an organic electroluminescent (EL) display.

FIG. 2 is a diagram illustrating a conveyance passage inside the media conveying apparatus 100.

The media conveying apparatus 100 includes a first media sensor 111, a feed roller 112, a separation roller 113, a second media sensor 114, a third media sensor 115, a first conveyance roller 116, a first driven roller 117, a fourth media sensor 118, an imaging device 119, a fifth media sensor 120, a second conveyance roller 121, and a second driven roller 122 along the conveyance passage.

The number of each of the feed roller 112, the separation roller 113, the first conveyance roller 116, the first driven roller 117, the second conveyance roller 121, and/or the second driven roller 122 is not limited to one but may be two or more. In this case, the two or more rollers of the feed rollers 112, the separation rollers 113, the first conveyance rollers 116, the first driven rollers 117, the second conveyance rollers 121, and/or the second driven roller 122 are aligned and spaced apart in the width direction A2 perpendicular to the media conveyance direction.

The upper face of the lower housing 101 forms a lower guide 101a for the media conveyance passage. The lower face of the upper housing 102 forms an upper guide 102a for the media conveyance passage.

The first media sensor 111 is located upstream from the feed roller 112 and the separation roller 113. The first media sensor 111 includes a contact detection sensor and detects whether a medium is placed on the media tray 103. The first media sensor 111 generates a first media signal of which the signal value changes depending on whether a medium is placed on the media tray 103 and outputs the generated first media signal. The first media sensor 111 is not limited to the contact sensor. The first media sensor 111 may be any other sensor that can detect the presence of a medium such as an optical sensor.

The feed roller 112 is located in the lower housing 101. The feed roller 112 is rotatable in a media feeding direction A4 and sequentially separates and feeds the media on the media tray 103 from the bottom. The separation roller 113 is a so-called brake roller or retard roller. The separation roller is located in the upper housing 102 and faces the feed roller 112. The separation roller 113 is stoppable or rotatable in a direction A5 opposite to the media feeding direction. Alternatively, the feed roller 112 may be located in the upper housing 102 and the separation roller 113 may be located in the lower housing 101 such that the feed roller 112 feeds the media on the media tray 103 from the top.

The second media sensor 114 is located downstream from the feed roller 112 and upstream from the first conveyance roller 116, particularly in the vicinity of the feed roller 112. The second media sensor 114 detects a medium conveyed to the position where the second media sensor 114 is located. The second media sensor 114 includes a light emitter, a light receiver, and a light guide. The light emitter and the light receiver are located on one side of the media conveyance passage. The light guide faces the light emitter and the light receiver across the media conveyance passage. The light emitter is, for example, a light-emitting diode (LED), and emits light toward the media conveyance passage. The light receiver is, for example, a photodiode and receives light emitted from the light emitter and guided by the light guide. When a medium is present at a position facing the second media sensor 114, the light emitted from the light emitter is blocked by the medium, and therefore the light receiver does not detect the light emitted from the light emitter. Based on the intensity of the light received by the light receiver, the second media sensor 114 generates and outputs a second media signal of which the signal value changes between when a medium is present at the position of the second media sensor 114 and when a medium is absent at the position of the second media sensor 114.

A reflector such as a mirror may be used instead of the light guide. The light emitter and the light receiver may be located facing each other with the media conveyance passage therebetween. Further, the second media sensor 114 may detect the presence of the medium with, for example, a contact sensor that causes a predetermined current to flow when a medium is in contact with the contact sensor or when no medium is in contact with the contact sensor.

The third media sensor 115 is located downstream from the second media sensor 114 and upstream from the first conveyance roller 116, in particular in the vicinity of the first conveyance roller 116, and detects a medium conveyed to the position where the third media sensor 115 is located. The third media sensor 115 includes a light emitter, a light receiver, and a light guide. The light emitter and the light receiver are located on one side of the media conveyance passage. The light guide member faces the light emitter and the light receiver across the media conveyance passage. The light emitter is, for example, an LED and emits light toward the media conveyance passage. The light receiver is, for example, a photodiode and receives light that is emitted by the light emitter and guided by the light guide. When a medium is present at a position facing the third media sensor 115, the light emitted from the light emitter is blocked by the medium, and therefore the light receiver does not detect the light emitted from the light emitter. Based on the intensity of the light received by the light receiver, the third media sensor 115 generates and outputs a third media signal of which the signal value changes between when a medium is present at the position of the third media sensor 115 and when a medium is absent at the position of the third media sensor 115.

A reflector such as a mirror may be used instead of the light guide. The light emitter and the light receiver may be located facing each other with the media conveyance passage therebetween. Further, the third media sensor 115 may detect the presence of the medium with, for example, a contact sensor that causes a predetermined current to flow when a medium is in contact with the contact sensor or when no medium is in contact with the contact sensor.

The first conveyance roller 116 and the first driven roller 117 are located downstream from the feed roller 112 and the separation roller 113 in the media conveyance direction A1 and face each other. The first conveyance roller 116 is located in the upper housing 102 and conveys the medium fed by the feed roller 112 and the separation roller 113 to the imaging device 119. Alternatively, the first conveyance roller 116 may be located in the lower housing 101 and the first driven roller 117 may be located in the upper housing 102.

The first conveyance roller 116 is an example of a conveyance roller. The first conveyance roller 116 rotates in a forward direction A6 and applies a force directing the medium downstream. Thus, the first conveyance roller 116 conveys the fed medium downstream. On the other hand, the first conveyance roller 116 stops or rotates in a reverse direction A7 and applies a force directing the medium upstream. Thus, the first conveyance roller 116 stops the forward movement of the leading end of the fed medium to align the leading end of the medium. In other words, the first conveyance roller 116 functions as a registration roller that corrects the inclination of the leading end of the fed medium by stopping or rotating in the reverse direction A7. The forward direction A6 is an example of a first direction. The reverse direction A7 is an example of a second direction opposite to the first direction. When the first conveyance roller 116 rotates in the forward direction A6, the first driven roller 117 is rotated in a forward direction A8 by the rotation of the first conveyance roller 116. When the first conveyance roller 116 rotates in the reverse direction A7, the first driven roller 117 is rotated in a reverse direction A9 by the rotation of the first conveyance roller 116.

The fourth media sensor 118 is located downstream from the first conveyance roller 116 and upstream from the imaging device 119, and detects a medium conveyed to the position where the fourth media sensor 118 is located. The fourth media sensor 118 includes a light emitter, a light receiver, and a light guide. The light emitter and the light receiver are located on one side of the media conveyance passage. The light guide member faces the light emitter and the light receiver across the media conveyance passage. The light emitter is, for example, an LED and emits light toward the media conveyance passage. The light receiver is, for example, a photodiode and receives light that is emitted by the light emitter and guided by the light guide. Based on the intensity of the light received by the light receiver, the fourth media sensor 118 generates and outputs a fourth media signal of which the signal value changes between when a medium is present at the position of the fourth media sensor 118 and when a medium is absent at the position of the fourth media sensor 118.

A reflector such as a mirror may be used instead of the light guide. The light emitter and the light receiver may be located facing each other with the media conveyance passage therebetween. Further, the fourth media sensor 118 may detect the presence of the medium with, for example, a contact sensor that causes a predetermined current to flow when a medium is in contact with the contact sensor or when no medium is in contact with the contact sensor.

The imaging device 119 is an example of an imaging device. The imaging device 119 is located downstream from the first conveyance roller 116 and upstream from the second conveyance roller 121 in the media conveyance direction A1. The imaging device 119 images the medium conveyed by the first conveyance roller 116 and the first driven roller 117. The imaging device 119 includes a first imaging device 119a and a second imaging device 119b facing each other across the media conveyance passage.

The first imaging device 119a includes a line sensor based on a unity-magnification optical system type contact image sensor (CIS) including complementary metal oxide semiconductor- (CMOS-) based imaging elements linearly arranged in a main scanning direction. The first imaging device 119a further includes a lens that forms an image on the imaging elements and an analog-to-digital (A/D) converter that electrical signals output from the imaging elements and performs analog-to-digital (A/D) conversion. The first imaging device 119a generates an input image by imaging the front side of a conveyed medium under control of a processing circuit described later and outputs the generated input image.

Similarly, the second imaging device 119b includes a line sensor based on a unity-magnification optical system type CIS including CMOS-based imaging elements linearly arranged in the main scanning direction. The second imaging device 119b further includes a lens that forms an image on the imaging elements and an A/D converter that amplifies electrical signals output from the imaging elements and performs A/D conversion. The second imaging device 119b generates an input image by imaging the back side of a conveyed medium under control of a processing circuit described later and outputs the generated input image.

The media conveying apparatus 100 may include either the first imaging device 119a or the second imaging device 119b and read only one side of the medium. Instead of the line sensor based on a unity-magnification optical system type CIS including CMOS-based imaging elements, a line sensor based on a unity-magnification optical system type CIS including charge-coupled device- (CCD-) based imaging elements may be used. A reduction optical system type line sensor including CMOS-based or CCD-based imaging elements may be used.

The fifth media sensor 120 is located downstream from the imaging device 119 and upstream from the second conveyance roller 121, and detects a medium conveyed to the position where the fifth media sensor 120 is located. The fifth media sensor 120 includes a light emitter, a light receiver, and a light guide. The light emitter and the light receiver are located on one side of the media conveyance passage. The light guide member faces the light emitter and the light receiver across the media conveyance passage. The light emitter is, for example, an LED and emits light toward the media conveyance passage. The light receiver is, for example, a photodiode and receives light that is emitted by the light emitter and guided by the light guide. Based on the intensity of the light received by the light receiver, the fifth media sensor 120 generates and outputs a fifth media signal of which the signal value changes between when a medium is present at the position of the fifth media sensor 120 and when a medium is absent at the position of the fifth media sensor 120.

A reflector such as a mirror may be used instead of the light guide. The light emitter and the light receiver may be located facing each other with the media conveyance passage therebetween. Further, the fifth media sensor 120 may detect the presence of the medium with, for example, a contact sensor that causes a predetermined current to flow when a medium is in contact with the contact sensor or when no medium is in contact with the contact sensor.

The second conveyance roller 121 and the second driven roller 122 are located downstream from the imaging device 119, that is, from the first conveyance roller 116 and the first driven roller 117 in the media conveyance direction A1 and face each other. The second conveyance roller 121 is located in the upper housing 102. The second conveyance roller 121 conveys the medium conveyed by the first conveyance roller 116 and the first driven roller 117 further downstream and ejects the medium to the ejection tray 104. Alternatively, the second conveyance roller 121 may be located in the lower housing 101 and the second driven roller 122 may be located in the upper housing 102.

As the feed roller 112 rotates in the media feeding direction A4, the medium is conveyed from the media tray 103 in the media conveyance direction A1 between the lower guide 101a and the upper guide 102a. The media conveying apparatus 100 has two feeding modes: a separation mode in which media are fed while being separated and a non-separation mode in which media are fed without being separated. The feeding mode is set by a user using the operation device 105 or an information processing apparatus connected to the media conveying apparatus 100 for communication. When the feeding mode is set to the separation mode, the separation roller 113 rotates in the direction A5 opposite to the media feeding direction or stops. Due to the action of the feed roller 112 and the separation roller 113, when a plurality of media is placed on the media tray 103, only a medium in contact with the feed roller 112 among the media placed on the media tray 103 is separated. This prevents the feeding of a medium other than the separated medium. In other words, the multi-feed is prevented. When the feeding mode is set to the non-separation mode, the separation roller 113 rotates in the media feeding direction opposite to the direction A5.

The medium is fed to a nip between the first conveyance roller 116 and the first driven roller 117 while being guided by the lower guide 101a and the upper guide 102b. As the first conveyance roller 116 and the first driven roller 117 rotate in the reverse directions A7 and A9, respectively, for a certain time period, the leading end of the medium is stopped at the nip between the first conveyance roller 116 and the first driven roller 117. During this time, the medium is pushed by the feed roller 112. As a result, the leading end of the medium is aligned. Thereafter, as the first conveyance roller 116 and the first driven roller 117 rotate in the forward directions A6 and A8, respectively, the medium is fed between the first imaging device 119a and the second imaging device 119b. After the imaging device 119 reads the medium, the medium is ejected to the ejection tray 104 as the second conveyance roller 121 and the second driven roller 122 rotate in the directions A10 and A11, respectively.

As illustrated in FIG. 2, the media conveying apparatus 100 includes a first motor 131, a second motor 132, and a third motor 133 as driving sources of the rollers.

The first motor 131 is located in the lower housing 101. The first motor 131 is coupled to the feed roller 112 via a first transmission assembly 131a and drives the feed roller 112. The first motor 131 generates a driving force for rotating the feed roller 112 according to a control signal from the processing circuit such that the feed roller 112 feeds a medium. Alternatively, the first motor 131 may be located in the upper housing 102.

The first transmission assembly 131a includes one or more pulleys, belts, and gears between the first motor 131 and a shaft 112a serving as a rotary shaft of the feed roller 112. The first transmission assembly 131a transmits the driving force generated by the first motor 131 to the feed roller 112.

The second motor 132 is an example of a motor. The second motor 132 is located in the upper housing 102 separately from the first motor 131. The second motor 132 is coupled to the separation roller 113 via a second transmission assembly 132a and drives the separation roller 113. The second motor 132 generates a driving force for rotating the separation roller 113 according to a control signal from the processing circuit such that the separation roller 113 separates, feeds, and conveys a medium. Alternatively, the second motor 132 may be located in the lower housing 101. Examples of the second motor 132 include a direct current (DC) motor such as a brushed DC motor. Alternatively, the second motor 132 may be another type of DC motor such as such as a brushless DC motor, or a stepping motor. The second motor 132 is designed such that the motor torque of the second motor 132 can be changed according to supplied electric power. The motor torque is an example of a motor torque.

The greater the amount of current supplied to the DC motor or the stepping motor, that is, the greater the amount of electric power supplied to the DC motor or the stepping motor, the greater the motor torque of the DC motor or the stepping motor. Conversely, the smaller the amount of current supplied to the DC motor or the stepping motor, that is, the smaller the amount of electric power supplied to the DC motor or the stepping motor, the smaller the motor torque of the DC motor or the stepping motor. Accordingly, the media conveying apparatus 100 can change the motor torque of the second motor 132 by changing the amount of electric power supplied to the second motor 132. The media conveying apparatus 100 can increase the motor torque of the second motor 132 by increasing the amount of electric power supplied to the second motor 132, and thus can increase the torque applied to the separation roller 113 (i.e., a load component applied to a medium by the separation roller 113). On the other hand, the media conveying apparatus 100 can reduce the motor torque of the second motor 132 by reducing the amount of electric power supplied to the second motor 132, and thus can reduce the torque applied to the separation roller 113 (i.e., a load component applied to a medium by the separation roller 113).

The second transmission assembly 132a includes one or more pulleys, belts, and gears between the second motor 132 and a shaft 113a serving as a rotary shaft of the separation roller 113. The second transmission assembly 132a transmits the driving force generated by the second motor 132 to the separation roller 113.

The media conveying apparatus 100 further includes a torque limiter 113b. The torque limiter 113b is located between the second motor 132 and the separation roller 113. In the example illustrated in FIG. 2, the torque limiter 113b is located on the shaft 113a serving as the rotary shaft of the separation roller 113. The torque limiter 113b defines a limit value of the torque applied to the separation roller 113. The limit value of the torque limiter 113b is set to prevent the rotational force from being transmitted through the torque limiter 113b when a single medium is conveyed, and to transmit the rotational force through the torque limiter 113b when multiple media are conveyed. As a result, when a single medium is conveyed, the separation roller 113 is rotated by the rotation of the feed roller 112 via the media being conveyed, without being rotated by the driving force from the second motor 132. When multiple media are conveyed, the separation roller 113 rotates in the direction A5 opposite to the media feeding direction and separates the medium in contact with the feed roller 112 from the other media to prevent the occurrence of multi-feed. At this time, instead of rotating in the direction A5 opposite to the media feeding direction, the separation roller 113 may be kept stationary such that the outer circumferential surface of the separation roller 113 applies a force in the direction A5 opposite to the media feeding direction to the media.

The third motor 133 is located in the upper housing 102 separately from the first motor 131 and the second motor 132. The third motor 133 is coupled to the first conveyance roller 116 and the second conveyance roller 121 via a third transmission assembly 133a and drives the first conveyance roller 116 and the second conveyance roller 121. The third motor 133 generates a driving force for rotating the first conveyance roller 116 and the second conveyance roller 121 according to a control signal from the processing circuit such that the first conveyance roller 116 and the second conveyance roller 121 convey and eject a medium. Alternatively, the third motor 133 may be located in the lower housing 101.

The third transmission assembly 133a includes one or more pulleys, belts, and gears between the third motor 133, a shaft 116a serving as a rotary shaft of the first conveyance roller 116, and a shaft 121a serving as a rotary shaft of the second conveyance roller 121. The third transmission assembly 133a transmits the driving force generated by the third motor 133 to the first conveyance roller 116 and the second conveyance roller 121.

As described above, the media conveying apparatus 100 includes the third motor 133 as a common motor for driving the first conveyance roller 116 and driving the second conveyance roller 121. Accordingly, the media conveying apparatus 100 can reduce the number of motors and reduce the cost, size, and weight of the media conveying apparatus 100.

The first driven roller 117 is a driven roller that is rotated by the rotation of the first conveyance roller 116. The second driven roller 122 is a driven roller that is rotated by the rotation of the second conveyance roller 121. Alternatively, the first driven roller 117 and/or the second driven roller 122 may be driven by the driving force from the third motor 133. In this case, one or more gears are further located between the shaft 116a of the first conveyance roller 116 and a shaft 117a serving as a rotary shaft of the first driven roller 117 and/or between the shaft 121a of the second conveyance roller 121 and a shaft 122a serving as a rotary shaft of the second driven roller 122, and the third transmission assembly 133a further transmits the driving force generated by the third motor 133 to the first driven roller 117 and/or the second driven roller 122.

FIG. 3 is a block diagram schematically illustrating a configuration of the media conveying apparatus 100.

The media conveying apparatus 100 further includes an interface device 134, a storage device 140, and a processing circuit 150, in addition to the configuration described above.

The interface device 134 includes an interface circuit compatible with a serial bus such as a universal serial bus (USB) and is electrically connected to an information processing apparatus (e.g., a personal computer or a mobile information processing terminal) to transmit and receive an input image and various kinds of information to and from the information processing apparatus. The interface device 134 may be substituted by a communication unit including an antenna to transmit and receive wireless signals and a wireless communication interface device to transmit and receive the signals through a wireless communication line according to a predetermined communication protocol. The predetermined communication protocol is, for example, a wireless local area network (LAN) communication protocol. The communication unit may include a wired communication interface device to transmit and receive signals through a wired communication line according to, for example, a wired LAN communication protocol.

The storage device 140 includes memories such as a random-access memory (RAM) and a read-only memory (ROM), a fixed disk device such as a hard disk, or a portable memory such as a flexible disk or an optical disc. The storage device 140 stores, for example, computer programs, databases, and tables used for various processes performed by the media conveying apparatus 100. The computer programs may be installed in the storage device 140 from a computer-readable portable recording medium using, for example, a known setup program. The portable recording medium is, for example, a compact disc read-only memory (CD-ROM) or a digital versatile disc read-only memory (DVD-ROM). The processing circuit 150 operates according to a program prestored in the storage device 140. The processing circuit 150 is, for example, a central processing unit (CPU). Alternatively, a digital signal processor (DSP), a large-scale integration (LSI), an application-specific integrated circuit (ASIC), or a field-programmable gate array (FPGA) may be used as the processing circuit 150.

The processing circuit 150 is connected to the operation device 105, the display device 106, the first media sensor 111, the second media sensor 114, the third media sensor 115, the fourth media sensor 118, the imaging device 119, the fifth media sensor 120, the first motor 131, the second motor 132, the third motor 133, the interface device 134, and the storage device 140, and controls these components. The processing circuit 150 controls the driving of the motors described above and the imaging by the imaging device 119 according to the media signals received from the media sensors described above. The processing circuit 150 acquires an input image from the imaging device 119 and transmits the input image to the information processing apparatus via the interface device 134. Further, the processing circuit 150 sets torque applied to the separation roller 113 based on the media signals received from the media sensors.

FIG. 4 is a block diagram schematically illustrating a configuration of the storage device 140 and the processing circuit 150.

As illustrated in FIG. 4, the storage device 140 stores a control program 141 and a setting program 142. These programs are functional modules implemented by software operating on a processor. The processing circuit 150 reads the programs from the storage device 140 and operates according to the read programs. Thus, the processing circuit 150 functions as a control unit 151 and a setting unit 152.

FIG. 5 is a flowchart illustrating an example of a media reading process performed by the media conveying apparatus 100. FIG. 6 is a continuation of the flowchart of FIG. 5.

A description is given below of the media reading process performed by the media conveying apparatus 100, with reference to the flowcharts of FIG. 5 and FIG. 6. The operation process described below is executed, for example, by the processing circuit 150 in cooperation with the components of the media conveying apparatus 100 according to the programs prestored in the storage device 140.

The control unit 151 waits until the control unit 151 receives an operation signal instructing the reading of media from the operation device 105 or the interface device 134 (step S101). The operation signal is output when the user inputs an instruction to read media using the operation device 105 or the information processing apparatus.

Subsequently, the control unit 151 acquires the first media signal from the first media sensor 111 and determines whether a medium is placed on the media tray 103 based on the acquired first media signal (step S102). When no medium is present on the media tray 103, the control unit 151 ends the series of steps.

By contrast, when a medium is placed on the media tray 103, the setting unit 152 sets the motor torque of the second motor 132 to a first motor torque value (step S103). The setting unit 152 sets the motor torque of the second motor 132 to the first motor torque value by setting the amount of electric power (current) supplied to the second motor 132 to the amount of electric power (current) corresponding to the first motor torque value. The first motor torque value is set to a value greater than the limit value of the torque limiter 113b. Since the motor torque of the second motor 132 exceeds the limit value of the torque limiter 113b, torque applied to the separation roller 113 is limited to the limit value of the torque limiter 113b. In other words, the setting unit 152 sets the torque applied to the separation roller 113 to the limit value of the torque limiter 113b, and sets the load component applied to the medium by the separation roller 113 to the limit value of the torque limiter 113b.

Subsequently, the control unit 151 drives the first motor 131 and the second motor 132 to rotate the feed roller 112 and the separation roller 113, respectively, to feed the medium (step S104). The control unit 151 rotates the feed roller 112 in the media feeding direction A4 and rotates the separation roller 113 in the direction A5 opposite to the media feeding direction.

FIG. 7 is a graph illustrating changes in the speed of the feed roller 112, the separation roller 113, and the first conveyance roller 116.

In FIG. 7, a graph G11 indicates a change in the speed of the feed roller 112, a graph G12 indicates a change in the speed of the separation roller 113, and a graph G13 indicates a change in the speed of the first conveyance roller 116. Since the speeds of the first driven roller 117, the second conveyance roller 121, and the second driven roller 122 change like the speed of the first conveyance roller 116, the change in the speed of the first conveyance roller 116 will be described below as a representative example. The horizontal axis of each of the graphs G11 to G13 indicates time, whereas the vertical axis of each of the graphs G11 to G13 indicates speed. The speed of each roller is a moving speed of the surface of each roller (i.e., a conveyance speed of the medium by each roller).

A graph G14 indicates a change in the signal value of the second media sensor 114. A graph G15 indicates a change in the signal value of the third media sensor 115. A graph G16 indicates a change in the signal value of the fourth media sensor 118. A graph G17 indicates a change in the signal value of the fifth media sensor 120. The horizontal axis of each of the graphs G14, G15, G16, and G17 indicates time, whereas the vertical axis of each of the graphs G14, G15, G16, and G17 indicates a signal value. In the present embodiment, when no medium is present at the position of each sensor, the signal value of the corresponding signal indicates L. By contrast, when a medium is present at the position of each sensor, the signal value of the corresponding signal indicates H.

In FIG. 7, time T1 indicates the time to start feeding media. As illustrated in FIG. 7, at the start of feeding of media, the control unit 151 sets the speed of the feed roller 112 to an initial speed V1. The initial speed V1 is set to a speed sufficiently lower than an intermediate speed V2 and a final speed V3 described later. As the control unit 151 sets the speed of the feed roller 112 at the start of feeding of media to the sufficiently low speed, media are reliably separated, and thus the occurrence of the multi-feed of media is prevented. Meanwhile, the control unit 151 sets the speed of the separation roller 113 to a speed U. The speed of the separation roller 113 does not change from the speed U thereafter. Further, the control unit 151 sets the speed of the first conveyance roller 116 to zero such that the first conveyance roller 116 does not rotate.

As illustrated in FIG. 7, after a predetermined through-up period has elapsed since the driving of each motor started at time T1, each roller rotates at the speed being set. Thereafter in substantially the same manner, when the control unit 151 changes the speeds of the rollers, the rollers rotate at the speeds being set after a predetermined through-up period or through-down period elapses from the change of the speeds of the rollers.

Subsequently, the control unit 151 waits until the leading end of the fed medium passes through the nip between the feed roller 112 and the separation roller 113 (step S105). In the following description, the nip between the feed roller 112 and the separation roller 113 may be referred to as a “separation area.” The control unit 151 periodically acquires the second media signal from the second media sensor 114 and determines that the leading end of the medium has passed through the position of the second media sensor 114 when the signal value of the second media signal changes from a value indicating the absence of a medium to a value indicating the presence of a medium. The control unit 151 determines that the leading end of the medium has passed through the separation area when the leading end of the medium has passed through the position of the second media sensor 114. Alternatively, the control unit 151 may determine that the leading end of the medium has passed through the separation area after the elapse of a preset time from the start of the feeding of the medium.

Subsequently, the control unit 151 changes the speed of the feed roller 112 (step S106).

In FIG. 7, time T2 indicates the time when the signal value of the second media signal changes from L to H, i.e., the time when the leading end of the medium has passed through the separation area. As illustrated in FIG. 7, the control unit 151 changes the speed of the feed roller 112 from the initial speed V1 to the intermediate speed V2 at the time T2. The intermediate speed V2 is set to a speed higher than the initial speed V1 and lower than the final speed V3 described later. As the control unit 151 increases the speed of the feed roller 112 when the leading edge of the medium has passed through the separation area, a time period from a time when the leading end of the medium passes through the separation area to a time when the leading end of the medium reaches the position of the first conveyance roller 116 is shorten, and thus the processing time of medium reading process is shorten.

Subsequently, the control unit 151 controls the third motor 133 to stop the first conveyance roller 116 (step S107).

As illustrated in FIG. 7, the control unit 151 stops the first conveyance roller 116 (i.e., changes the speed to zero) at the time T2 when the leading end of the medium has passed through the separation area. However, when the leading end of a medium fed first among media placed on the media tray 103 has passed through the separation area, the first conveyance roller 116 has not yet rotated. Accordingly, when the first medium is fed, the operation of step S107 may be omitted. The control unit 151 aligns the leading end of a medium by stopping or reversely rotating the first conveyance roller 116 when the leading end of the medium reaches the position of the first conveyance roller 116 in a process described later. As the control unit 151 stops the first conveyance roller 116 when the leading end of the medium has passed through the separation area in consideration of the through-down period, the leading end of the medium is reliably stopped when the leading end of the medium reaches the position of the first conveyance roller 116.

Subsequently, the control unit 151 waits until the leading end of the fed medium reaches just in front of the nip between the first conveyance roller 116 and the first driven roller 117 (step S108). In the following description, the nip between the first conveyance roller 116 and the first driven roller 117 may be referred to as a “conveyance area.” The control unit 151 periodically acquires the third media signal from the third media sensor 115 and determines that the leading end of the medium has passed through the position of the third media sensor 115 when the signal value of the third media signal changes from a value indicating the absence of a medium to a value indicating the presence of a medium. The control unit 151 determines that the leading end of the medium has reached just in front of the conveyance area when the leading end of the medium has passed through the position of the third media sensor 115. Alternatively, the control unit 151 may determine that the leading end of the medium has reached just in front of the conveyance area after the elapse of a preset time from the start of the feeding of the medium.

Subsequently, the setting unit 152 sets the motor torque of the second motor 132 to a second motor torque value (step S109). The setting unit 152 sets the motor torque of the second motor 132 to the second motor torque value by setting the amount of electric power (current) supplied to the second motor 132 to the amount of electric power (current) corresponding to the second motor torque value. The second motor torque value is set to a value smaller than the limit value of the torque limiter 113b. Since the motor torque of the second motor 132 is smaller than the limit value of the torque limiter 113b, the torque having the second motor torque value generated by the second motor 132 is applied to the separation roller 113. In other words, the setting unit 152 sets the torque applied to the separation roller 113 to the second motor torque value, and sets the load component applied to the medium by the separation roller 113 to the second motor torque value.

Subsequently, the control unit 151 changes the speed of the feed roller 112 (step S110).

In FIG. 7, time T3 indicates the time when the signal value of the third media signal changes from L to H, i.e., the time when the leading end of the medium reaches just in front of the conveyance area. As illustrated in FIG. 7, the control unit 151 changes the speed of the feed roller 112 from the intermediate speed V2 to the final speed V3. The final speed V3 is set to a speed higher than the initial speed V1 and the intermediate speed V2. As the control unit 151 increases the speed of the feed roller 112 when the leading end of the medium reaches just in front of the conveyance area, the leading end of the medium contact the first conveyance roller 116 and/or the first driven roller 117 with stronger force. Accordingly, the position of the leading end of the medium is more favorably aligned.

Subsequently, the control unit 151 controls the third motor 133 to stop the first conveyance roller 116 or rotate the first conveyance roller 116 in the reverse direction A7 (step S111).

As illustrated in FIG. 7, the control unit 151 rotates the first conveyance roller 116 in the reverse direction A7 (i.e., changes the speed to a negative value) at the time T3 when the leading end of the medium reaches just in front of the conveyance area. At this time, the first driven roller 117 is rotated in the reverse direction A9 by the rotation of the first conveyance roller 116. Although FIG. 7 illustrates an example in which the control unit 151 rotates the first conveyance roller 116 in the reverse direction A7 at the time T3, the control unit 151 may stop the first conveyance roller 116 (i.e., change the speed to zero). In this case, the first driven roller 117 stops together with the first conveyance roller 116.

Subsequently, the control unit 151 waits until a predetermined time elapses while controlling the first conveyance roller 116 to rotate in the reverse direction A7 or stop to align the leading end of the medium (step S112). The predetermined time is set to a maximum value or an average value of times taken until the inclination of a medium is corrected (eliminated) by stopping the medium by the first conveyance roller 116 and the first driven roller 117 in experiments in which various types of media are fed while being inclined at various angles.

FIG. 8 is a schematic diagram illustrating how the leading end of a medium is aligned.

FIG. 8 illustrates an example in which multiple media M1 to M4 are collectively placed on the media tray 103. As illustrated in FIG. 8, only the medium M1 in contact with the feed roller 112 is separated and fed among the media M1 to M4 placed on the media tray 103 and reaches the nip between the first conveyance roller 116 and the first driven roller 117. At this time, as the first conveyance roller 116 and the first driven roller 117 stop or rotate in the reverse directions A7 and A9, respectively, the forward movement of the leading end of the medium M1 is stopped by the first conveyance roller 116 and the first driven roller 117. Meanwhile, the feed roller 112 keeps pushing the medium M1 downstream, and thus the medium M1 is pushed downstream while bending upward. Thus, when the medium M1 has been fed while being inclined with respect to the width direction A2, the leading end of the medium M1 is located along the width direction A2 at the nip between the first conveyance roller 116 and the first driven roller 117. Accordingly, the control unit 151 can correct the skew of a medium by stopping the first conveyance roller 116 or rotating the first conveyance roller 116 in the reverse direction A7 for a predetermined time.

As described above, in step S103, the setting unit 152 sets the torque applied to the separation roller 113 at the start of feeding of media to the limit value of the torque limiter 113b. On the other hand, in step S109, the setting unit 152 sets the torque applied to the separation roller 113 at the alignment of the leading end of a medium to the second motor torque value that is smaller than the limit value of the torque limiter 113b. In other words, the setting unit 152 sets the torque applied to the separation roller 113 after the first conveyance roller 116 starts the alignment of the leading end of a medium to a value smaller than the torque applied to the separation roller 113 before the first conveyance roller 116 starts the alignment of the leading end of the medium.

Thus, the separation roller 113 can apply a sufficiently large load component to media placed on the media tray 103 at the start of feeding of media and separate the media favorably. On the other hand, the separation roller 113 reduces a load component applied to a medium for which the separation is completed and the alignment of the leading end is performed, and thus reduces a force with which the medium is nipped by the feed roller 112 and the separation roller 113. Accordingly, a medium of which the leading end has been aligned is moved more smoothly at the nip between the feed roller 112 and the separation roller 113, and thus the control unit 151 can perform medium skew correction more efficiently.

Specifically, the setting unit 152 sets the motor torque of the second motor 132 before the first conveyance roller 116 starts aligning the leading end of a medium to the first motor torque value that is greater than the limit value of the torque limiter 113b. On the other hand, the setting unit 152 sets the motor torque of the second motor 132 after the first conveyance roller 116 starts aligning the leading end of a medium to the second motor torque value smaller than the limit value of the torque limiter 113b. Thus, the setting unit 152 can reliably set torque applied to the separation roller 113 at the start of feeding of media, i.e., at the separation of media, to a torque value required for separating the media, and the separation roller 113 can separate the media favorably.

Subsequently, the control unit 151 controls the third motor 133 to rotate the first conveyance roller 116 in the forward direction A6 (step S113).

As illustrated in FIG. 7, the control unit 151 rotates the first conveyance roller 116 in the forward direction A6 (changes the speed to a positive value) when a predetermined time P1 has elapsed from the time T3 when the leading end of the medium reaches just in front of the conveyance area. At this time, the first driven roller 117 is rotated in the forward direction A8 by the rotation of the first conveyance roller 116. The control unit 151 sets the speed of the first conveyance roller 116 to a speed W. The speed W of the first conveyance roller 116 is set to a speed higher than the final speed V3 of the feed roller 112. Thus, the control unit 151 can eliminate the medium bending that occurs while the first conveyance roller 116 is aligning the leading end of the medium in a shorter time. The speed W of the first conveyance roller 116 may be set to a speed equal to or lower than the final speed V3 of the feed roller 112.

Subsequently, the control unit 151 waits until the leading end of the fed medium passes through the conveyance area (step S114). The control unit 151 periodically acquires the fourth media signal from the fourth media sensor 118 and determines that the leading end of the medium has passed through the position of the fourth media sensor 118 when the signal value of the fourth media signal changes from a value indicating the absence of a medium to a value indicating the presence of a medium. The control unit 151 determines that the leading end of the medium has passed through the conveyance area when the leading end of the medium has passed through the position of the fourth media sensor 118. Alternatively, the control unit 151 may determine that the leading end of the medium has passed through the conveyance area after the elapse of a preset time from the rotation of the first conveyance roller 116 in the forward direction A6.

Subsequently, the control unit 151 controls the imaging device 119 to start imaging the medium (step S115).

In FIG. 7, time T4 indicates the time when the signal value of the fourth media signal changes from L to H, i.e., the time when the leading end of the medium has passed through the conveyance area. By controlling the imaging device 119 to start imaging the medium when the leading end of the medium has passed through the conveyance area, the control unit 151 can control the imaging device 119 to start imaging of the medium immediately before the medium reaches the imaging position of the imaging device 119. Thus, the control unit 151 can prevent an area where the background appears in the input image from increasing and prevent the data amount of the input image from increasing.

Subsequently, the control unit 151 waits until the leading end of the fed medium passes through the nip between the second conveyance roller 121 and the second driven roller 122 (step S116). In the following description, the nip between the second conveyance roller 121 and the second driven roller 122 may be referred to as an “ejection area.” The control unit 151 periodically acquires the fifth media signal from the fifth media sensor 120 and determines that the leading end of the medium has passed through the ejection area when the signal value of the fifth media signal changes from a value indicating the absence of a medium to a value indicating the presence of a medium. Alternatively, the control unit 151 may determine that the leading end of the medium has passed through the ejection area after the elapse of a preset time from the rotation of the first conveyance roller 116 in the forward direction A6.

Subsequently, the setting unit 152 sets the motor torque of the second motor 132 to the first motor torque value (step S117). In other words, in substantially the same manner as the operation of step S103, the setting unit 152 sets the torque applied to the separation roller 113 to the limit value of the torque limiter 113b, and sets the load component applied to the medium by the separation roller 113 to the limit value of the torque limiter 113b.

In FIG. 7, time T5 indicates the time when the signal value of the fifth media signal changes from L to H, i.e., the time when the leading end of the medium has passed through the ejection area. When the leading end of the medium has passed through the ejection area, i.e., when the medium being conveyed is reliably nipped by the second conveyance roller 121 and the second driven roller 122, the setting unit 152 returns torque applied to the separation roller 113 to the limit value of the torque limiter 113b. Thus, torque applied to the separation roller 113 is set again to a torque value suitable for the separation of media, and the media conveying apparatus 100 can prevent the occurrence of multi-feed of media.

As described above, the setting unit 152 sets the torque applied to the separation roller 113 during a period P2 from the time T3 when the leading end of the medium has reached just in front of the conveyance area to the time T5 when the leading end of the medium has passed through the ejection area to a value smaller than torque applied to the separation roller 113 during periods other than the period P2. In other words, the setting unit 152 sets torque applied to the separation roller 113 from when the first conveyance roller 116 starts the alignment of the leading end of a medium to when the leading end of the medium passes through the second conveyance roller 121 to a value smaller than torque applied to the separation roller 113 before the first conveyance roller 116 starts the alignment of the leading end of the medium.

As described above, the medium is bent upward by the alignment of the leading end of the medium by the first conveyance roller 116. If torque applied to the separation roller 113 is increased while the medium is being bent upward, a large load is applied to the medium, and thus wrinkles may occur. The setting unit 152 increases (returns) the torque applied to the separation roller 113 after the leading end of the medium has passed through the position of the second conveyance roller 121. The occurrence of wrinkles in the medium is prevented or reduced by increasing the torque applied to the separation roller 113 when the bending of the medium is eliminated. Further, the influence of the load applied to the medium is reduced and the occurrence of wrinkles in the medium is prevented or reduced by increasing the torque applied to the separation roller 113 when the medium is stably nipped by the first conveyance roller 116 and the second conveyance roller 121.

Subsequently, the control unit 151 controls the first motor 131 to stop the feed roller 112 (step S118).

As illustrated in FIG. 7, the control unit 151 stops the feed roller 112 (i.e., changes the speed to zero) at the time T5 when the leading end of the medium has passed through the ejection area. As a result, the medium is thereafter conveyed by the first conveyance roller 116 and the second conveyance roller 121, whereas the feed roller 112 is rotated by the medium being conveyed. By stopping the feed roller 112, the control unit 151 can prevent the medium from being jammed due to the medium being pushed by the feed roller 112 and bent between the feed roller 112 and the first conveyance roller 116.

Subsequently, the control unit 151 determines whether a medium remains on the media tray 103 based on the first media signal received from the first media sensor 111 (step S119).

When a medium remains on the media tray 103, the control unit 151 waits until the trailing end of the conveyed medium passes through the separation area (step S120). The control unit 151 periodically acquires the second media signal from the second media sensor 114 and determines that the trailing end of the medium has passed through the position of the second media sensor 114 when the signal value of the second media signal changes from a value indicating the presence of a medium to a value indicating the absence of a medium. The control unit 151 determines that the trailing end of the medium has passed through the separation area when the trailing end of the medium has passed through the position of the second media sensor 114. Alternatively, the control unit 151 may determine that the trailing end of the medium has passed through the separation area after the elapse of a preset time from the start of the feeding of the medium.

Subsequently, the control unit 151 drives the first motor 131 to rotate the feed roller 112 to feed the medium (step S121). The control unit 151 sets the speed of the feed roller 112 to the initial speed V1 and rotates the feed roller 112 in the media feeding direction A4 in substantially the same manner as the operation of step S104.

In FIG. 7, time T6 indicates the time when the signal value of the second media signal changes from H to L, i.e., the time when the trailing end of the medium has passed through the separation area. When the trailing end of the preceding medium has passed through the separation area, the control unit 151 re-rotates the feed roller 112 to start feeding of the following medium.

Subsequently, the control unit 151 waits until the trailing end of the conveyed medium passes through the imaging position of the imaging device 119 (step S122). The control unit 151 periodically acquires the fifth media signal from the fifth media sensor 120 and determines that the trailing end of the medium has passed through the position of the fifth media sensor 120 when the signal value of the fifth media signal changes from a value indicating the presence of a medium to a value indicating the absence of a medium. The control unit 151 determines that the trailing end of the medium has passed through the imaging position when the trailing end of the medium has passed through the position of the fifth media sensor 120. Alternatively, the control unit 151 may determine that the trailing end of the medium has passed through the imaging position after the elapse of a preset time from the start of the feeding of the medium.

Subsequently, the control unit 151 acquires an input image from the imaging device 119 and transmits (i.e., outputs) the acquired input image to the information processing apparatus via the interface device 134 (step S123).

In FIG. 7, time T7 indicates the time when the signal value of the fifth media signal changes from H to L, i.e., the time when the trailing end of the medium has passed through the imaging position. The control unit 151 acquires an input image from the imaging device 119 when the trailing end of the preceding medium has passed through the imaging position.

The control unit 151 then returns to step S105 and repeats the operations of the step S105 and subsequent steps for the following medium. In this case, in step S107, the control unit 151 controls the third motor 133 to stop the first conveyance roller 116 when the leading end of the following medium has passed through the separation area.

By contrast, when no medium remains on the media tray 103 in step S119, the control unit 151 waits until the trailing end of the conveyed medium passes through the imaging position of the imaging device 119 in substantially the same manner as the operation of step S122 (step S124).

Subsequently, the control unit 151 waits until the trailing end of the conveyed medium passes through the ejection area (step S126). The control unit 151 determines that the trailing end of the medium has passed through the ejection area when a certain time period has elapsed since the trailing end of the medium has passed through the position of the fifth media sensor 120. The certain time period is set to a time taken for a medium to move from the fifth media sensor 120 to the downstream end of the ejection area. Alternatively, the control unit 151 may determine that the trailing end of the medium has passed through the ejection area after the elapse of a preset time from the start of the feeding of the medium.

Subsequently, the control unit 151 controls the second motor 132 and the third motor 133 to stop the separation roller 113, the first conveyance roller 116, the first driven roller 117, the second conveyance roller 121, and/or the second driven roller 122 (step S127). Then, the control unit 151 ends the series of steps.

As described above in detail, the media conveying apparatus 100 reduces torque applied to the separation roller 113 during the alignment of the leading end of a medium by the first conveyance roller 116 located downstream from the separation roller 113. Thus, the media conveying apparatus 100 can align the leading end of the medium with the first conveyance roller 116 more favorably.

Accordingly, the media conveying apparatus 100 can prevent a medium from being skewed, thus can reduce the occurrence of a media jam or the occurrence of an image cut-off in an input image.

FIG. 9 is a flowchart illustrating another example of a part of the media reading process.

The process of flowchart illustrated in FIG. 9 is executed instead of the process of flowchart illustrated in FIG. 6. Since the operations in steps S214, S216 to S217, and S218 to S227 of FIG. 9 are respectively the same as the operations in steps S114, S115 to S116, and S118 to S127 of FIG. 6, redundant descriptions thereof will be omitted. A description is given below of step S215 alone.

After waiting until the leading end of the fed medium passes through the conveyance area in step 214, the setting unit 152 sets the motor torque of the second motor 132 to the first motor torque value (step S215). In other words, in substantially the same manner as the operation of step S117, the setting unit 152 sets the torque applied to the separation roller 113 to the limit value of the torque limiter 113b, and sets the load component applied to the medium by the separation roller 113 to the limit value of the torque limiter 113b. The setting unit 152 sets the motor torque of the second motor 132 to the first motor torque value before controlling the imaging device 119 to start imaging the medium in step S216.

In the example illustrated in FIG. 7, the setting unit 152 returns the torque applied to the separation roller 113 to the limit value of the torque limiter 113b at the time T4 when the leading end of the medium passes through the conveyance area, i.e., immediately before the medium being conveyed is imaged by the imaging device 119. Thus, torque applied to the separation roller 113 is set again to a torque value suitable for the separation of media, and the media conveying apparatus 100 can prevent the occurrence of multi-feed of media.

As described above, the setting unit 152 sets the torque applied to the separation roller 113 during a period P3 from the time T3 when the leading end of the medium has reached just in front of the conveyance area to the time T4 when the leading end of the medium has passed through the conveyance area to a value smaller than the torque applied to the separation roller 113 during periods other than the period P3. In other words, the setting unit 152 sets the torque applied to the separation roller 113 from when the first conveyance roller 116 starts the alignment of the leading end of a medium to when the leading end of the medium reaches the imaging position of the imaging device 119 to a value smaller than the torque applied to the separation roller 113 before the first conveyance roller 116 starts the alignment of the leading end of the medium. Accordingly, the media conveying apparatus 100 can align the leading end of a medium favorably while preventing a load component applied to a medium during the imaging of the medium and reducing the occurrence of the multi-feed of media. Thus, the media conveying apparatus 100 can prevent the occurrence of jitter (shaking) of the medium in the input image.

As described above in detail, the media conveying apparatus 100 can more favorably align the leading end of the medium with the first conveyance roller 116 when torque applied to the separation roller 113 is changed before the medium is imaged.

FIG. 10 is a block diagram schematically illustrating a configuration of a processing circuit 250 of a media conveying apparatus according to another embodiment. The processing circuit 250 substitutes for the processing circuit 150 and performs the media reading process instead of the processing circuit 150. The processing circuit 250 includes a control circuit 251 and a setting circuit 252. These circuits may be implemented by, for example, independent integrated circuits, microprocessors, or firmware.

The control circuit 251 is an example of a control unit and functions in the same or substantially the same manner as the control unit 151. The control circuit 251 receives the operation signal from the operation device 105 or the interface device 134. Further, the control circuit 251 receives the first media signal, the second media signal, the third media signal, the fourth media signal, and the fifth media signal from the first media sensor 111, the second media sensor 114, the third media sensor 115, the fourth media sensor 118, and the fifth media sensor 120, respectively. The control circuit 251 controls the first motor 131, the second motor 132, and the third motor 133 based on the received signals, acquires an input image from the imaging device 119, and outputs the input image to the interface device 134.

The setting circuit 252 is an example of a setting unit and functions in the same or substantially the same manner as the setting unit 152. The setting circuit 252 receives the third media signal, the fourth media signal, and/or the fifth media signal from the third media sensor 115, the fourth media sensor 118, and/or the fifth media sensor 120, respectively, and sets the motor torque of the second motor 132 based on the received signals.

As described above in detail, the media conveying apparatus including the processing circuit 250 also can align the leading end of a medium with the first conveyance roller 116 more favorably.

Although the preferred embodiments have been described above, the embodiments are not limited thereto. For example, the torque limiter 113b may be omitted in the media conveying apparatus. In this case, in step S103 of FIG. 5, step S117 of FIG. 6, or step S215 of FIG. 9, the first motor torque value is set to the same value as the limit value of the torque limiter 113b. In other words, the first motor torque value is set to a value such that the separation roller 113 rotates in the opposite direction A5 to the media feeding direction when multiple media are conveyed, and the separation roller 113 is rotated by the rotation of the feed roller 112 when only one medium is conveyed. Also in this case, the media conveying apparatus can align the leading end of a medium favorably while reducing the occurrence of the multi-feed of media. Further, since the torque limiter 113b is omitted, the media conveying apparatus can reduce the cost of the apparatus.

Alternatively, in the media conveying apparatus, an electromagnetic clutch may be used instead of the torque limiter 113b. The setting unit 152 changes torque applied to the separation roller 113 by controlling the electromagnetic clutch instead of changing the amount of electric power (current) supplied to the second motor 132. In this case, the second motor 132 does not have to be designed to be able to change the motor torque. Also in this case, the media conveying apparatus can align the leading end of a medium favorably while reducing the occurrence of the multi-feed of media.

Still alternatively, in the media conveying apparatus, the first conveyance roller 116 and the second conveyance roller 121 may be driven by different motors, respectively.

Aligning the leading end of a medium by a conveyance roller more favorably is required in a media conveying apparatus.

According to one or more embodiments, the media conveying apparatus, the media conveying method, and the control program can align the leading end of a medium with the conveyance roller more favorably.

The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of the present invention. Any one of the above-described operations may be performed in various other ways, for example, in an order different from the one described above.

The functionality of the elements disclosed herein may be implemented using circuitry or processing circuitry which includes general purpose processors, special purpose processors, integrated circuits, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), and/or combinations thereof which are configured or programmed, using one or more programs stored in one or more memories, to perform the disclosed functionality. Processors are considered processing circuitry or circuitry as they include transistors and other circuitry therein. In the disclosure, the circuitry, units, or means are hardware that carry out or are programmed to perform the recited functionality. The hardware may be any hardware disclosed herein which is programmed or configured to carry out the recited functionality.

There is a memory that stores a computer program which includes computer instructions. These computer instructions provide the logic and routines that enable the hardware (e.g., processing circuitry or circuitry) to perform the method disclosed herein. This computer program can be implemented in known formats as a computer-readable storage medium, a computer program product, a memory device, a record medium such as a CD-ROM or DVD, and/or the memory of an FPGA or ASIC.

	Number	Date	Country
Parent	PCT/JP2022/012438	Mar 2022	WO
Child	18882193		US

MEDIA CONVEYING APPARATUS, MEDIA CONVEYING METHOD, AND NON-TRANSITORY RECORDING MEDIUM

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CPC

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CROSS-REFERENCE TO RELATED APPLICATION

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