Medium feeding device, medium feeding method, and control program

Abstract

To provide a medium feeding device, a medium feeding method, and a control program capable of appropriately feeding a plurality of types of media.SOLUTION: A medium feeding device includes: a pick roller that is disposed above a placement table, is provided so as to be capable of raising, and feeds a medium placed on the placement table; a pressure member that can apply a downward pressing force to the pick roller; and, when a tip of the medium does not reach a predetermined position within a predetermined time after the start of feeding the medium, or when a moving speed during feeding of the medium is equal to or lower than a predetermined speed, a control part that raises the placement table so as to press the medium placed on the placement table against the pick roller. The pressure member does not apply the pressing force to the pick roller when the pick roller is arranged at a first position, and applies the pressing force to the pick roller when the control part raises the placement table and the pick roller is arranged at a second position higher than the first position.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a medium feeding device, a medium feeding method, and a control program. [Background technology]

[0002] Media feeding devices such as scanners are required to support various types of media. In such media feeding devices, if the force with which the rollers that feed the media press the media is too strong, media jams or multiple feeds may occur. On the other hand, if the force with which the rollers that feed the media press the media is too weak, the media may slip and fail to feed depending on the type of media.

[0003] A sheet material supplying device is disclosed that includes a liftable hopper on which sheet material is loaded, and a pick-up roller that is rotatably supported and is pressed against the sheet material as the hopper is lifted and lowered to feed the sheet material (see Patent Document 1). This sheet material supplying device detects the contact pressure of the pick-up roller against the sheet material, and adjusts the pressure that presses the pick-up roller against the sheet material based on the detected contact pressure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-37575 A Summary of the Invention [Problem to be solved by the invention]

[0005] A media feeding device is required to appropriately feed a plurality of types of media.

[0006] An object of the present invention is to provide a medium feeding device, a medium feeding method, and a control program that are capable of appropriately feeding a plurality of types of media. [Means for solving the problem]

[0007] A medium feeding device according to one aspect of the present invention comprises a mounting table that is capable of being raised and on which a medium is placed, a pick roller that is arranged above the mounting table and is capable of being raised and that feeds the medium placed on the mounting table, a pressing member that is capable of applying a downward pressing force to the pick roller, and a control unit that raises the mounting table so as to press the medium placed on the mounting table toward the pick roller if the leading edge of the medium does not reach a predetermined position within a predetermined time after starting to feed the medium or if the moving speed during feeding of the medium is equal to or lower than a predetermined speed, and the pressing member does not apply a pressing force to the pick roller when the pick roller is located at a first position, and applies a pressing force to the pick roller when the mounting table is raised by the control unit and the pick roller is located at a second position higher than the first position.

[0008] A medium feeding method according to one aspect of the present invention includes feeding a medium placed on the mounting table by a pick roller that is arranged to be able to be lifted and is arranged above a mounting table on which the medium is placed, applying a downward pressing force to the pick roller by a pressing member, and raising the mounting table so as to press the medium placed on the mounting table toward the pick roller if the leading edge of the medium does not reach a predetermined position within a predetermined time after starting to feed the medium or if the moving speed of the medium during feeding is equal to or lower than a predetermined speed, wherein the pressing member does not apply a pressing force to the pick roller when the pick roller is located at a first position, and applies a pressing force to the pick roller when the mounting table is raised and the pick roller is located at a second position higher than the first position.

[0009] A control program according to one aspect of the present invention is a control program for a medium feeding device having a mounting table that is capable of being raised and on which a medium is placed, a pick roller that is arranged above the mounting table and is capable of being raised and that feeds the medium placed on the mounting table, and a pressing member that can apply a downward pressing force to the pick roller, and if the leading edge of the medium does not reach a predetermined position within a predetermined time after starting to feed the medium, or if the moving speed of the medium during feeding is equal to or lower than a predetermined speed, causes the medium feeding device to raise the mounting table so as to press the medium placed on the mounting table toward the pick roller, and the pressing member causes the medium feeding device to not apply a pressing force to the pick roller when the pick roller is located at a first position, and to apply a pressing force to the pick roller when the pick roller is located at a second position higher than the first position due to the lifting of the mounting table. Effect of the Invention

[0010] According to the present invention, the medium feeding device, the medium feeding method, and the control program are capable of appropriately feeding a plurality of types of media. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing a medium feeding device 100. [Diagram 2] 2 is a diagram for explaining a transport path inside the medium feeding device 100. FIG. [Diagram 3] 2 is a schematic diagram for explaining a pick roller 112. FIG. [Figure 4] 2 is a schematic diagram for explaining a pick roller 112. FIG. [Diagram 5] 2 is a schematic diagram for explaining a pick roller 112. FIG. [Figure 6] 1 is a block diagram showing a schematic configuration of a medium feeding device 100. FIG. [Figure 7] FIG. 2 is a diagram showing a schematic configuration of a storage device 140 and a processing circuit 150. [Figure 8] 10 is a flowchart illustrating an example of the operation of a medium reading process. [Figure 9] 10 is a flowchart illustrating an example of the operation of a medium reading process. [Figure 10] 10 is a graph 1000 showing the relationship between the angle of the arm 122 and the applied pressure. [Figure 11] 2 is a schematic diagram for explaining a pick roller 112. FIG. [Figure 12] 2 is a schematic diagram for explaining a pick roller 112. FIG. [Figure 13] 2 is a schematic diagram for explaining a pick roller 112. FIG. [Figure 14] FIG. 13 is a diagram showing a schematic configuration of a processing circuit 350 according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a medium feeding device, a medium feeding method, and a control program according to one aspect of the present invention will be described with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to the embodiments, but extends to the inventions described in the claims and their equivalents.

[0013] 1 is a perspective view showing a medium feeding device 100 configured as an image scanner. Medium feeding device 100 conveys a medium, which is an original document, and captures an image. The medium is paper, cardboard, card, or the like. Medium feeding device 100 may be a facsimile, a copier, a multifunction printer (MFP, Multifunction Peripheral), or the like. Note that the medium being conveyed may not be an original document, but may be a print target, or the like, and medium feeding device 100 may be a printer, or the like.

[0014] 1, arrow A1 indicates the substantially vertical direction (height direction), arrow A2 indicates the medium transport direction, arrow A3 indicates the medium discharge direction, and arrow A4 indicates the width direction perpendicular to the medium transport direction A2 or the medium discharge direction A3. In the following, upstream refers to the upstream of the medium transport direction A2 or the medium discharge direction A3, and downstream refers to the downstream of the medium transport direction A2 or the medium discharge direction A3.

[0015] The medium feeding device 100 includes a first housing 101, a second housing 102, a placement table 103, a discharge table 104, an operation device 105, a display device 106, and the like.

[0016] The second housing 102 is disposed inside the first housing 101 and rotatably engaged with the first housing 101 by a hinge so that the second housing 102 can be opened and closed when a medium is jammed or when the inside of the medium feeding device 100 is cleaned.

[0017] The placement table 103 engages with the first housing 101 so as to place the medium to be transported thereon. The placement table 103 is provided on the side surface of the first housing 101 on the medium supply side so as to be movable in the height direction A1, i.e., so as to be able to rise and fall. The placement table 103 is disposed at the bottom end position so that the medium can be easily placed on it when the medium is not being transported, and when the medium is being transported, the uppermost medium placed on the placement table 103 rises to a position where it comes into contact with a pick roller, which will be described later.

[0018] The discharge stage 104 is formed on the second housing 102. The discharge stage 104 places the media discharged from the discharge ports of the first housing 101 and the second housing 102 thereon.

[0019] The operation device 105 has an input device such as a button and an interface circuit for acquiring a signal from the input device, accepts an input operation by a user, and outputs an operation signal according to the user's input operation. The display device 106 has a display including a liquid crystal, an organic EL (Electro-Luminescence), or the like, and an interface circuit for outputting image data to the display, and displays the image data on the display. The display device 106 may be a liquid crystal display with a touch panel function. In that case, the operation device 105 has an interface circuit for acquiring an input signal from the touch panel.

[0020] FIG. 2 is a diagram for explaining the transport path inside the medium feeding device 100. As shown in FIG.

[0021] The transport path inside the media feeding device 100 has a first media sensor 111, a pick roller 112, a speed sensor 113, a feed roller 114, a separation roller 115, a second media sensor 116, first to sixth transport rollers 117a-f, first to sixth driven rollers 118a-f, a third media sensor 119, an imaging device 120, and a moving mechanism 121, etc.

[0022] The number of each of the pick roller 112, the feed roller 114, the separation roller 115, the first to sixth conveying rollers 117a-f, and / or the first to sixth driven rollers 118a-f is not limited to one, and may be more than one. In this case, the multiple feed rollers 114, the separation roller 115, the first to sixth conveying rollers 117a-f, and / or the first to sixth driven rollers 118a-f are arranged at intervals in the width direction A4.

[0023] The second housing 102 is disposed opposite the first housing 101 across the medium transport path. The surface of the first housing 101 facing the second housing 102 forms a first guide 101a of the medium transport path, and the surface of the second housing 102 facing the first housing 101 forms a second guide 102a of the medium transport path.

[0024] The first medium sensor 111 is disposed on the mounting table 103, that is, upstream of the feed roller 114 and the separation roller 115, and detects the state of the medium on the mounting table 103. The first medium sensor 111 determines whether or not a medium is placed on the mounting table 103 by using a contact detection sensor that passes a predetermined current when the medium is in contact or not in contact. The first medium sensor 111 generates and outputs a first medium signal whose signal value changes depending on whether the medium is placed on the mounting table 103 or not. Note that the first medium sensor 111 is not limited to a contact detection sensor, and any other sensor capable of detecting the presence or absence of a medium, such as a light detection sensor, may be used as the first medium sensor 111.

[0025] Pick roller 112 is disposed in second housing 102, upstream of feed roller 114 and separation roller 115 in media transport direction A2. Pick roller 112 is disposed above mounting table 103, and feeds media placed on mounting table 103. Pick roller 112 comes into contact with the uppermost medium among the media placed on mounting table 103, which has been raised to approximately the same height as the media transport path, and feeds the medium downstream.

[0026] The speed sensor 113 is disposed in the second housing 102 downstream of the pick roller 112 and upstream of the feed roller 114 and the separation roller 115 in the medium conveying direction A2, particularly in the vicinity of the feed roller 114, and detects the moving speed (feed speed) of the medium being fed. The speed sensor 113 is, for example, an encoder, and has a disk formed with a number of slits (light transmission holes) and arranged to rotate according to the medium being fed, and a light emitter and a light receiver arranged to face each other across the disk. The light emitter is an LED (Light Emitting Diode) or the like, and emits light toward the disk (light receiver). The light receiver is a photodiode or the like, and receives the light emitted by the light emitter through the disk. The light receiver detects the number of times that a state in which a slit exists between the light emitter and the light receiver changes to a state in which no slit exists and the light is blocked by the disk within a predetermined period. The optical receiver detects the movement distance of the fed medium by multiplying the detected number of changes by the distance that the outer circumferential surface of the speed sensor 113 moves when the disk rotates the distance between two adjacent slits. The optical receiver also detects the movement speed of the fed medium by dividing the detected movement distance by the predetermined period during which the number of changes was detected. The speed sensor 113 generates and outputs a speed signal indicating the detected movement speed.

[0027] The speed sensor 113 is not limited to an optical encoder, and may be any encoder such as a mechanical encoder, a magnetic encoder, or an electromagnetic induction encoder. The speed sensor 113 may also be an optical sensor. The optical sensor includes a light emitter and a light receiver. The light emitter is an LED or the like, and emits light toward the uppermost medium among the media placed on the placement table 103, i.e., the medium being fed. Meanwhile, the light receiver captures an image according to the received light at a predetermined period and detects a common portion between the latest image and the immediately preceding image. The light receiver detects the movement direction and movement amount of the medium being fed based on the change in the position of the detected common portion within the image. The light receiver detects the movement speed of the medium being fed by dividing the movement amount in the medium transport direction A2 by a predetermined period that is the image capture interval of the image.

[0028] The feed roller 114 is provided in the second housing 102 downstream of the pick roller 112, and feeds the medium placed on the placement table 103 and fed by the pick roller 112 further downstream. The separation roller 115 is provided in the first housing 101 facing the feed roller 114. The separation roller 115 is a so-called brake roller, and is provided so as to be able to stop. The feed roller 114 and the separation roller 115 function as a separation unit that separates the media, and separates the media and feeds them one by one. The feed roller 114 is provided above the separation roller 115, and the medium feeding device 100 feeds the media by a so-called top-take method. A separation pad may be used instead of the separation roller 115.

[0029] The second medium sensor 116 is disposed downstream of the feed roller 114 and the separation roller 115 and upstream of the first conveying roller 117a and the first driven roller 118a in the medium conveying direction A2, and detects the medium conveyed to the arrangement position. In particular, the second medium sensor 116 is disposed near the feed roller 114 and the separation roller 115. The second medium sensor 116 includes a light emitter and a light receiver provided on one side of the medium conveying path, and a light guide tube provided at a position facing the light emitter and the light receiver across the medium conveying path. The light emitter is an LED or the like, and emits light toward the medium conveying path. On the other hand, the light receiver is a photodiode or the like, and receives the light emitted by the light emitter and guided by the light guide tube. The second medium sensor 116 generates and outputs a second medium signal whose signal value changes depending on whether a medium is present or not at the position of the second medium sensor 116 based on the intensity of the light received by the light receiver.

[0030] A reflective member such as a mirror may be used instead of the light guide tube. The light emitter and the light receiver may be provided facing each other across the medium transport path. The second medium sensor 116 may be any other sensor capable of detecting the presence or absence of a medium, such as a contact detection sensor that passes a predetermined current when the medium is in contact or when the medium is not in contact.

[0031] The first to sixth transport rollers 117a-f and the first to sixth driven rollers 118a-f are arranged facing each other downstream of the feed roller 114 and the separation roller 115 in the medium transport direction A2. The first to sixth transport rollers 117a-f and the first to sixth driven rollers 118a-f transport the medium fed by the feed roller 114 and the separation roller 115 downstream. The sixth transport roller 117f and the sixth driven roller 118f discharge the medium to the discharge tray 104.

[0032] The third medium sensor 119 is disposed downstream of the first transport roller 117a and the first driven roller 118a and upstream of the second transport roller 117b and the second driven roller 118b in the medium transport direction A2, and detects the medium transported to the arrangement position. In particular, the third medium sensor 119 is disposed near the first transport roller 117a and the first driven roller 118a. The third medium sensor 119 may be disposed downstream of the second transport roller 117b and the second driven roller 118b. The third medium sensor 119 includes a light emitter and a light receiver provided on one side of the medium transport path, and a light guide tube provided at a position facing the light emitter and the light receiver across the medium transport path. The light emitter is an LED or the like, and emits light toward the medium transport path. On the other hand, the light receiver is a photodiode or the like, and receives the light emitted by the light emitter and guided by the light guide tube. The third medium sensor 119 generates and outputs a third medium signal whose signal value changes depending on whether a medium is present or not at the position of the third medium sensor 119, based on the intensity of light received by the optical receiver.

[0033] A reflective member such as a mirror may be used instead of the light guide tube. The light emitter and the light receiver may be provided facing each other across the medium transport path. The second medium sensor 116 may be any other sensor capable of detecting the presence or absence of a medium, such as a contact detection sensor that passes a predetermined current when the medium is in contact or when the medium is not in contact.

[0034] The imaging device 120 is disposed downstream of the first and second transport rollers 117a-b in the medium transport direction A2, and captures images of the medium transported by the first and second transport rollers 117a-b and the first and second driven rollers 118a-b. The imaging device 120 includes a first imaging device 120a and a second imaging device 120b disposed opposite each other across the medium transport path. The first imaging device 120a is provided in the second housing 102, and the second imaging device 120b is provided in the first housing 101.

[0035] The first imaging device 120a has a line sensor using a CIS (Contact Image Sensor) of a life-size optical system type having imaging elements using CMOS (Complementary Metal Oxide Semiconductor) linearly arranged in the main scanning direction. The first imaging device 120a also has a lens that forms an image on the imaging elements, and an A / D converter that amplifies and analog-to-digital (A / D) converts the electrical signal output from the imaging elements. The first imaging device 120a captures an image of the surface of the medium being transported, generates an input image, and outputs it.

[0036] Similarly, the second imaging device 120b has a line sensor using a CIS of a life-size optical system type having CMOS imaging elements arranged in a line in the main scanning direction. The second imaging device 120b also has a lens that forms an image on the imaging element, and an A / D converter that amplifies and analog-to-digital (A / D) converts the electrical signal output from the imaging element. The second imaging device 120b captures the back side of the medium being transported to generate an input image and output it.

[0037] The medium feeding device 100 may have only one of the first imaging device 120a and the second imaging device 120b arranged to read only one side of the medium. Also, instead of a CIS line sensor of an equal magnification optical system type having a CMOS imaging element, a CIS line sensor of an equal magnification optical system type having a CCD (Charge Coupled Device) imaging element may be used. Also, a reduction optical system type line sensor having a CMOS or CCD imaging element may be used.

[0038] The medium placed on the placement table 103 is transported between the first guide 101a and the second guide 102a in the medium transport direction A2 by the rotation of the pick roller 112 and the feed roller 114 in the medium feed direction A11 and A12, respectively. The medium feeding device 100 has a separation mode in which the medium is separated while being fed, and a non-separation mode in which the medium is not separated while being fed. The feeding mode is set by the user using the operation device 105 or an information processing device that is communicatively connected to the medium feeding device 100. When the feeding mode is set to the separation mode, the separation roller 115 rotates or stops in the direction of the arrow A13, i.e., in the opposite direction to the medium feeding direction. This restricts the feeding of media other than the separated media (preventing double feeding). On the other hand, when the feeding mode is set to the non-separation mode, the separation roller 115 rotates in the opposite direction to the arrow A13, i.e., in the medium feeding direction.

[0039] The medium is guided by the first guide 101a and the second guide 102a and sent to the imaging position of the imaging device 120 by the rotation of the first and second transport rollers 117a-b in the directions of arrows A14-15, and is imaged by the imaging device 120. Furthermore, the medium is discharged onto the discharge table 104 by the rotation of the third to sixth transport rollers 117c-f in the directions of arrows A16-19, respectively.

[0040] The moving mechanism 121 raises and lowers the mounting table 103. The moving mechanism 121 includes a first motor 121a, a pinion 121b, a rack 121c, and the like. The pinion 121b and the rack 121c are disposed at one or both ends of the mounting table 103 in the width direction A4. The first motor 121a rotates under control of a processing circuit described later, and generates a driving force for raising and lowering the mounting table 103. The pinion 121b is attached to the rotating shaft of the first motor 121a, and the pinion 121b is meshed with the rack 121c. The rack 121c is provided so as to be movable up and down along a guide portion such as a rail (not shown) formed along the height direction A1. The mounting table 103 is attached to the rack 121c, and the mounting table 103 is provided so as to be raised and lowered according to the rotation of the pinion 121b. The moving mechanism 121 may raise and lower the mounting table 103 using any member such as a solenoid, a belt, and / or a cam instead of or in addition to the motor, the pinion, and / or the rack.

[0041] 3, 4, and 5 are schematic diagrams for explaining the pick roller 112. FIG.

[0042] As shown in FIGS. 3, 4 and 5, the medium feeding device 100 further includes an arm 122, a first pressing member 123, a second pressing member 124, a first pick roller sensor 125, and a second pick roller sensor 126, and the like.

[0043] The arm 122 extends along the medium transport direction A2 and is provided on the second housing 102 so as to be rotatable (swingable) about the shaft portion 122a. The pick roller 112 is attached to an upstream end portion 122b of the arm 122. Since the arm 122 is provided so as to be swingable about the shaft portion 122a, the pick roller 112 is provided so as to be movable (swingable) in the height direction A1, i.e., to be able to rise and fall, about the shaft portion 122a of the arm 122.

[0044] The first pressing member 123 is an example of a pressing member. The first pressing member 123 is an elastic member such as a compression coil spring, a torsion coil spring, a leaf spring, or rubber. The first pressing member 123 is disposed above the arm 122 and generates an elastic force downward. One end of the first pressing member 123 is fixed to the frame 102b fixed to the second housing 102, and the other end of the first pressing member 123 is disposed at a position facing the protrusion 122c fixed to the upper end of the arm 122. When the other end of the first pressing member 123 abuts against the protrusion 122c, the first pressing member 123 presses the protrusion 122c downward. Thus, the first pressing member 123 is provided so as to be able to apply a first pressing force downward to the pick roller 112. The first pressing force is an example of a pressing force. By using an elastic member as the first pressing member 123, the medium feeding device 100 can apply the first pressing force to the pick roller 112 stably and at low cost.

[0045] The second pressing member 124 is an elastic member such as a tension coil spring. The second pressing member 124 is disposed above the downstream end 122d of the arm 122, and generates an elastic force in an upward direction. One end of the second pressing member 124 is fixed to the frame 102b, and the other end of the second pressing member 124 is attached to the downstream end 122d of the arm 122. The second pressing member 124 applies a second downward pressing force to the pick roller 112 attached to the upstream end 122b of the arm 122 by pulling the downstream end 122d of the arm 122 upward.

[0046] A compression coil spring, a torsion coil spring, a leaf spring, rubber, or the like may be used as the second pressing member 124. In this case, the second pressing member 124 is disposed above the upstream end 122b of the arm 122 so as to generate a downward elastic force. In this case, the second pressing member 124 presses the upstream end 122b of the arm 122 downward, thereby applying a second downward pressing force to the pick roller 112 attached to the upstream end 122b of the arm 122. The second pressing member 124 may be omitted, and only a downward force due to its own weight may be applied to the arm 122.

[0047] When the second pressing member 124 applies the second pressing force to the pick roller 112, the pick roller 112 is stopped by a stopper (not shown) and placed in the lowest initial position when it is not in contact with the medium placed on the placement table 103 as shown in Fig. 3. When the pick roller 112 is placed in the initial position, the first pressing member 123 is not in contact with the protrusion 122c and does not apply the first pressing force to the pick roller 112.

[0048] On the other hand, as shown in FIG. 4, when the placement table 103 is raised, the pick roller 112 comes into contact with the medium placed on the placement table 103, is pushed up by the medium placed on the placement table 103, and is positioned at a first position above the initial position. When the pick roller 112 is positioned at the first position, the pick roller 112 presses the medium placed on the placement table 103 downward by the second pressing force of the second pressing member 124 and / or its own weight. This generates an appropriate frictional force between the pick roller 112 and the medium, and the pick roller 112 can feed the medium appropriately. When the pick roller 112 is positioned at the first position, the first pressing member 123 does not come into contact with the protrusion 122c, and does not apply the first pressing force to the pick roller 112.

[0049] As shown in FIG. 5, when the placement table 103 is further raised from the position shown in FIG. 5, the pick roller 112 is further pushed up by the medium placed on the placement table 103, and is raised to a second position above the first position. When the pick roller 112 is placed at the second position, the pick roller 112 presses the medium placed on the placement table 103 downward by the second pressing force of the second pressing member 124 and / or its own weight, in the same manner as when the pick roller 112 is placed at the first position. That is, the second pressing member 124 applies the second pressing force to the pick roller 112 whether the pick roller 112 is placed at the first position or the second position. This generates an appropriate frictional force between the pick roller 112 and the medium, and the pick roller 112 can feed the medium appropriately. Furthermore, when pick roller 112 is disposed at the second position, first pressing member 123 comes into contact with protrusion 122c and applies a first pressing force to pick roller 112 via protrusion 122c. This generates a greater frictional force between pick roller 112 and the medium, enabling pick roller 112 to feed the medium with greater force.

[0050] First pick roller sensor 125 and second pick roller sensor 126 are examples of sensors for detecting the position of the pick roller.

[0051] The first pick roller sensor 125 includes a first light emitter 125a and a first light receiver 125b fixed on the second housing 102 and arranged opposite to each other. The first light emitter 125a is an LED or the like, and emits light toward the first light receiver 125b. On the other hand, the first light receiver 125b is a photodiode or the like, and receives the light emitted by the first light emitter 125a. A first shielding member 125c is provided on the side of the arm 122. As shown in FIG. 3, the first shielding member 125c is arranged so as to be located between the first light emitter 125a and the first light receiver 125b when the pick roller 112 is arranged at the initial position. On the other hand, as shown in FIG. 4 and FIG. 5, the first shielding member 125c is arranged so as not to be located between the first light emitter 125a and the first light receiver 125b when the pick roller 112 is arranged at the first position or the second position, that is, when the pick roller 112 is not arranged at the initial position. The first pick roller sensor 125 generates and outputs a first pick roller signal whose signal value changes depending on whether the pick roller 112 is positioned at the initial position or not, based on the intensity of light received by the first light receiver 125b.

[0052] The second pick roller sensor 126 includes a second light emitter 126a and a second light receiver 126b fixed on the second housing 102 and arranged opposite to each other. The second light emitter 126a is an LED or the like, and emits light toward the second light receiver 126b. On the other hand, the second light receiver 126b is a photodiode or the like, and receives the light emitted by the second light emitter 126a. A second shielding member 126c is provided on the side of the arm 122. As shown in FIG. 3 and FIG. 4, the first shielding member 125c is arranged so as to be located between the second light emitter 126a and the second light receiver 126b when the pick roller 112 is arranged in the initial position or the first position, that is, when the pick roller 112 is not arranged in the second position. On the other hand, as shown in FIG. 5, the first shielding member 125c is arranged so as not to be located between the second light emitter 126a and the second light receiver 126b when the pick roller 112 is arranged in the second position. The second pick roller sensor 126 generates and outputs a second pick roller signal whose signal value changes depending on whether the pick roller 112 is positioned at the second position or not, based on the intensity of light received by the second light receiver 126b.

[0053] In addition, the first light receiver 125b and the first light receiver 125b, and / or the second light emitter 126a and the second light receiver 126b may be provided on the side of the arm 122, and the first shielding member 125c and the second shielding member 126c may be fixed onto the second housing 102.

[0054] FIG. 6 is a block diagram showing a schematic configuration of the medium feeding device 100. As shown in FIG.

[0055] In addition to the above-mentioned components, the medium feeding device 100 further includes a second motor 131, an interface device 132, a storage device 140, a processing circuit 150, and the like.

[0056] The second motor 131 includes one or more motors, and rotates the pick roller 112, the feed roller 114, the separation roller 115, and the first to sixth transport rollers 117a-f to feed and transport the medium in response to a control signal from the processing circuit 150. In the following, of the motors included in the second motor 131, the motor for rotating the feed roller 114 may be referred to as a feed motor. Note that the first to sixth driven rollers 118a-f may be provided so as to rotate according to the driving force of the second motor 131, rather than being driven to rotate by the first to sixth transport rollers 117a-f.

[0057] The interface device 132 has an interface circuit conforming to a serial bus such as USB, and is electrically connected to an information processing device (not shown, for example, a personal computer, a mobile information terminal, etc.) to transmit and receive input images and various information. Also, instead of the interface device 132, a communication unit having an antenna for transmitting and receiving wireless signals and a wireless communication interface circuit for transmitting and receiving signals through a wireless communication line in accordance with a predetermined communication protocol may be used. The predetermined communication protocol is, for example, a wireless LAN (Local Area Network). The communication unit may have a wired communication interface circuit for transmitting and receiving signals through a wired communication line in accordance with a communication protocol such as a wired LAN.

[0058] The storage device 140 includes a memory device such as a random access memory (RAM) or a read only memory (ROM), a fixed disk device such as a hard disk, or a portable storage device such as a flexible disk or an optical disk. The storage device 140 also stores computer programs, databases, tables, and the like used for various processes of the medium feeding device 100. The computer programs may be installed in the storage device 140 from a computer-readable portable recording medium using a known setup program or the like. 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 computer programs may be distributed from a server or the like and installed in the storage device 140.

[0059] The processing circuit 150 operates based on a program previously stored in the storage device 140. The processing circuit is, for example, a CPU (Central Processing Unit). The processing circuit 150 may be, for example, a DSP (digital signal processor), an LSI (large scale integration), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field-Programmable Gate Array).

[0060] The processing circuit 150 is connected to the operation device 105, the display device 106, the first medium sensor 111, the speed sensor 113, the second medium sensor 116, the third medium sensor 119, the imaging device 120, the first pick roller sensor 125, the second pick roller sensor 126, the first motor 121a, the second motor 131, the interface device 132, the storage device 140, and the like, and controls each of these components. The processing circuit 150 performs drive control of the first motor 121a and the second motor 131, image capture control of the imaging device 120, and the like, based on signals received from each sensor. The processing circuit 150 acquires an input image from the imaging device 120, and transmits it to the information processing device via the interface device 132.

[0061] FIG. 7 is a diagram showing a schematic configuration of the storage device 140 and the processing circuit 150. As shown in FIG.

[0062] 7, the storage device 140 stores a control program 141, an image acquisition program 142, and the like. Each of these programs is a functional module implemented by software that runs on a processor. The processing circuitry 150 reads each program stored in the storage device 140 and operates according to the read program. In this way, the processing circuitry 150 functions as a control unit 151 and an image acquisition unit 152.

[0063] 8 and 9 are flowcharts showing an example of the operation of the medium reading process of the medium feeding device 100. In FIG.

[0064] An example of the operation of the medium reading process of the medium feeding device 100 will be described below with reference to the flowcharts shown in Figures 8 and 9. The flow of the operation described below is executed mainly by the processing circuit 150 in cooperation with each element of the medium feeding device 100 based on a program previously stored in the storage device 140. This flowchart describes the case where the feeding mode is set to the separation mode. Also, it is assumed that the placement table 103 is placed in the lowest position before this flowchart is executed.

[0065] First, the control unit 151 waits until a user inputs an instruction to read a medium using the operation device 105 or an information processing device, and an operation signal instructing the user to read a medium is received from the operation device 105 or the interface device 132 (step S101).

[0066] Next, control unit 151 acquires a medium signal from first medium sensor 111, and determines whether or not a medium is placed on mounting table 103 based on the acquired medium signal (step S102). If no medium is placed on mounting table 103, control unit 151 ends the series of steps.

[0067] On the other hand, when a medium is placed on the placement table 103, the control unit 151 drives the first motor 121a, controls the moving mechanism 121 to raise the placement table 103, and places the pick roller 112 at the first position (step S103). The control unit 151 rotates the first motor 121a in a direction to move the placement table 103 upward. The control unit 151 periodically acquires a first pick roller signal from the first pick roller sensor 125. The control unit 151 stops the first motor 121a when the signal value of the first pick roller signal changes from a state indicating that the pick roller 112 is placed at the initial position to a state indicating that the pick roller 112 is not placed at the initial position. As a result, the control unit 151 places the pick roller 112 at the first position where the medium can be fed.

[0068] Next, the control unit 151 drives the second motor 131 to rotate the separation roller 115, the first to sixth conveying rollers 117a-f, and / or the first to sixth driven rollers 118a-f (step S104). At this time, the pick roller 112 and the feeding roller 114 are not yet rotating, and the medium is not fed.

[0069] Next, the control unit 151 drives the second motor 131 to rotate the feed roller 114 and the pick roller 112 to feed the medium (step S105). Note that the control unit 151 starts the rotation of the feed roller 114 and then the rotation of the pick roller 112. This allows the medium feeding device 100 to prevent the medium from being bent between the pick roller 112 and the feed roller 114 due to the pick roller 112 starting to rotate before the feed roller 114, thereby preventing a medium jam from occurring.

[0070] Next, control unit 151 determines whether the leading edge of the medium has passed through the separation unit (step S106). Control unit 151 periodically acquires a second medium signal from second medium sensor 116, and determines that second medium sensor 116 has detected the leading edge of the medium when the signal value of the second medium signal changes from a value indicating a state in which the medium is not present to a value indicating a state in which the medium is present. Control unit 151 determines that the leading edge of the medium has passed through the separation unit when second medium sensor 116 detects the leading edge of the medium. If the leading edge of the medium has passed through the separation unit, control unit 151 transitions the process to step S121.

[0071] On the other hand, if the leading edge of the medium has not yet passed the separation section, the control unit 151 determines whether the moving speed of the medium during feeding is equal to or lower than the predetermined speed (step S107). The control unit 151 acquires a speed signal from the speed sensor 113, and determines whether the moving speed indicated by the speed signal is equal to or lower than the predetermined speed, thereby determining whether the moving speed of the medium during feeding is equal to or lower than the predetermined speed. The predetermined speed is set in advance to, for example, the minimum moving speed when the medium is normally fed in a prior experiment in which various types of media are fed. If the moving speed of the medium during feeding is equal to or lower than the predetermined speed, the control unit 151 shifts the process to step S112.

[0072] If the moving speed of the medium during feeding is higher than the predetermined speed, the control unit 151 judges whether the drive amount of the feeding motor is equal to or greater than the predetermined amount (step S108). The predetermined amount is set in advance to, for example, the maximum drive amount of the feeding motor until the medium passes through the separation unit when the medium is normally fed in a previous experiment in which various types of media are fed. If the drive amount of the feeding motor is still less than the predetermined amount, the control unit 151 returns the process to step S106 and repeats the processes from step S106 onwards.

[0073] On the other hand, when the drive amount of the feed motor becomes equal to or greater than the predetermined amount, the control unit 151 determines that a failure in feeding the medium has occurred. Then, the control unit 151 determines whether the number of times that the medium feeding has been retried (re-feeded) is equal to or greater than the predetermined number (step S109). The medium feeding retry is performed by stopping the pick roller 112 and the feed roller 114 once and rotating them again. The predetermined number is preset to an arbitrary number equal to or greater than 0 (for example, 1 or 2). When the number of times that the medium feeding retry has been performed is equal to or greater than the predetermined number, the control unit 151 determines that the leading edge of the medium has not reached the predetermined position within a predetermined time from the start of feeding the medium, and shifts the process to step S112. The predetermined time is the time required to drive the feed motor by a predetermined amount multiplied by the number of times that the feed motor has been driven by a predetermined amount. The predetermined position is the arrangement position of the second medium sensor 116.

[0074] On the other hand, if the number of retries to feed the medium is still less than the predetermined number, the control unit 151 controls the second motor 131 to temporarily stop the pick roller 112 and the feed roller 114 (step S110). Note that the control unit 151 stops the rotation of the pick roller 112 and then the feed roller 114. This allows the medium feeding device 100 to prevent the medium from bending between the pick roller 112 and the feed roller 114 due to the feed roller 114 stopping before the pick roller 112, causing a medium jam.

[0075] Next, control unit 151 drives second motor 131 to rotate feed roller 114 and pick roller 112 again to re-feed the medium (step S111). Note that control unit 151 starts the rotation of feed roller 114 and then the rotation of pick roller 112, similar to the processing of step S105. Next, control unit 151 returns the processing to step S106, and repeats the processing from step S106 onwards.

[0076] On the other hand, if the moving speed during feeding of the medium in step S107 is equal to or lower than the predetermined speed, or if the leading edge of the medium does not reach the predetermined position within the predetermined time after feeding of the medium is started in step S109, control unit 151 controls second motor 131 to temporarily stop pick roller 112 and feed roller 114 (step S112). Note that control unit 151 stops the rotation of pick roller 112 and then stops the rotation of feed roller 114, similar to the process of step S110.

[0077] Next, the control unit 151 drives the first motor 121a and controls the moving mechanism 121 to further raise the placement table 103, and places the pick roller 112 at the second position (step S113). The control unit 151 rotates the first motor 121a in a direction to move the placement table 103 upward. The control unit 151 periodically acquires a second pick roller signal from the second pick roller sensor 126. The control unit 151 stops the first motor 121a when the signal value of the second pick roller signal changes from a state indicating that the pick roller 112 is not placed at the second position to a state indicating that the pick roller 112 is placed at the second position. As a result, the control unit 151 places the pick roller 112 at the second position, which is higher than the first position.

[0078] In this way, when the leading edge of the medium does not reach a predetermined position within a predetermined time after starting to feed the medium, or when the moving speed during feeding of the medium is equal to or lower than a predetermined speed, control unit 151 raises mounting table 103 so as to press the medium placed on mounting table 103 toward pick roller 112. When pick roller 112 is placed at the second position as a result of control unit 151 raising mounting table 103, first pressing member 123 applies a first pressing force to pick roller 112. This generates a greater frictional force between pick roller 112 and the medium, and allows medium feeding device 100 to re-feed the medium that has failed to be fed with a greater force.

[0079] Furthermore, the control unit 151 detects that the pick roller 112 has moved to the second position or a position above the second position using the second pick roller sensor 126, and stops the placement table 103 when the pick roller 112 is located at the second position or a position above the second position. A position above the second position is an example of a third position. By using the second pick roller sensor 126, the medium feeding device 100 can determine with high accuracy whether or not the first pressing member 123 is applying a first pressing force downward to the pick roller 112. Therefore, when a feeding failure of the medium occurs, the medium feeding device 100 can reliably apply the first pressing force to the pick roller 112, thereby increasing the possibility of successful re-feeding.

[0080] Next, the control unit 151 drives the second motor 131 to rotate the feed roller 114 and the pick roller 112 again, in the same manner as in the process of step S111, and causes the medium to be fed again (step S114).

[0081] Next, the control unit 151 determines whether or not the leading edge of the medium has passed through the separation unit, similarly to the process of step S106 (step S115).

[0082] If the leading edge of the medium has not yet passed through the separation unit, the control unit 151 determines whether the drive amount of the feed motor is equal to or greater than a predetermined amount (step S116), in the same manner as in step S108. If the drive amount of the feed motor is still less than the predetermined amount, the control unit 151 returns the process to step S115, and repeats the processes from step S115 onward.

[0083] On the other hand, when the drive amount of the feed motor becomes equal to or greater than the predetermined amount, the control unit 151 determines that the medium could not be fed properly. Then, the control unit 151 executes abnormality processing (step S117) and ends the series of steps. As abnormality processing, the control unit 151 controls the second motor 131 to stop the pick roller 112, the feed roller 114, the separation roller 115, the first to sixth conveying rollers 117a-f, and / or the first to sixth driven rollers 118a-f. As abnormality processing, the control unit 151 also drives the first motor 121a and controls the moving mechanism 121 to lower the placement table 103 to the lowest position, and places the pick roller 112 in the initial position. As abnormality processing, the control unit 151 may also notify the user by displaying information indicating that the medium could not be fed properly on the display device 106 or transmitting the information to the information processing device via the interface device 132.

[0084] On the other hand, if the leading edge of the medium has passed the separation unit in step S115, the control unit 151 controls the second motor 131 to temporarily stop the pick roller 112 and the feed roller 114, similar to the process in step S110 (step S118).

[0085] Next, the control unit 151 drives the first motor 121a and controls the moving mechanism 121 to lower the placement table 103, and places the pick roller 112 at the first position (step S119). The control unit 151 rotates the first motor 121a in a direction to move the placement table 103 downward. The control unit 151 periodically acquires a first pick roller signal from the first pick roller sensor 125. When the signal value of the first pick roller signal changes from a state indicating that the pick roller 112 is not placed at the initial position to a state indicating that the pick roller 112 is placed at the initial position, the control unit 151 temporarily stops the first motor 121a. Next, the control unit 151 rotates the first motor 121a in a direction to move the placement table 103 upward. The control unit 151 again periodically acquires the first pick roller signal from the first pick roller sensor 125. Controller 151 stops first motor 121a when the signal value of the first pick roller signal changes from a state indicating that pick roller 112 is located at the initial position to a state indicating that pick roller 112 is not located at the initial position, thereby causing controller 151 to relocate pick roller 112 to the first position.

[0086] Next, the control unit 151 drives the second motor 131 to rotate the feed roller 114 and the pick roller 112 again, in the same manner as in the process of step S111, and causes the medium to be fed again (step S120).

[0087] Next, control unit 151 waits until the leading edge of the medium passes the position of first conveyor roller 117a (step S121). Control unit 151 periodically acquires a third medium signal from third medium sensor 119, and determines that third medium sensor 119 has detected the leading edge of the medium when the signal value of the third medium signal changes from a value indicating a state in which no medium is present to a value indicating a state in which a medium is present. Control unit 151 determines that the leading edge of the medium has passed the position of first conveyor roller 117a when third medium sensor 119 detects the leading edge of the medium.

[0088] Next, the control unit 151 controls the second motor 131 to stop the pick roller 112 and the feed roller 114 (step S122), similar to the process of step S110. After that, the medium is transported by the first transport roller 117a and the first driven roller 118a.

[0089] Next, the image acquisition unit 152 acquires an input image from the imaging device 120, and outputs the acquired input image by transmitting it to the information processing device via the interface device 132 (step S123). The image acquisition unit 152 causes the imaging device 120 to start imaging before the leading edge of the medium reaches the imaging position of the imaging device 120, for example, at the timing when the third medium sensor 119 detects the leading edge of the medium. The image acquisition unit 152 also causes the imaging device 120 to end imaging after the trailing edge of the medium passes the imaging position of the imaging device 120, for example, at the timing when a predetermined time has elapsed since the third medium sensor 119 detected the trailing edge of the medium, and acquires an input image from the imaging device 120. The image acquisition unit 152 periodically acquires a third medium signal from the third medium sensor 119, and determines that the third medium sensor 119 has detected the trailing edge of the medium when the signal value of the third medium signal changes from a value indicating a state in which the medium is present to a value indicating a state in which the medium is not present. The predetermined time is set to the time it takes for the medium to move from the third medium sensor 119 to the imaging position plus a margin.

[0090] Next, control unit 151 determines whether or not a medium remains on mounting table 103 based on the medium signal received from first medium sensor 111 (step S124).

[0091] If a medium remains on placement table 103, control unit 151 determines whether pick roller 112 is located at the initial position (step S125). Control unit 151 acquires a first pick roller signal from first pick roller sensor 125, and determines whether pick roller 112 is located at the initial position based on the acquired first pick roller signal. If pick roller 112 is not located at the initial position, that is, if pick roller 112 is located at the first position, control unit 151 returns the process to step S105 without executing any particular process, and repeats the processes from step S105 onwards.

[0092] On the other hand, if pick roller 112 is located at the initial position, that is, if pick roller 112 is not located at the first position, control unit 151 places pick roller 112 at the first position (step S126) in the same manner as in the process of step S103. Next, control unit 151 returns the process to step S105 and repeats the processes from step S105 onwards.

[0093] On the other hand, if no media remain on the mounting table 103 in step S124, the control unit 151 controls the second motor 131 to stop the separation roller 115, the first to sixth conveying rollers 117a-f, and / or the first to sixth driven rollers 118a-f (step S127).

[0094] Next, the control unit 151 drives the first motor 121a to control the moving mechanism 121 to lower the placement table 103 to the lowest position, and places the pick roller 112 in the initial position (step S128), thereby completing the series of steps.

[0095] Note that either the process of step S107 or the process of steps S109 to S111 may be omitted. When the processes of steps S109 to S111 are omitted, the control unit 151 executes abnormality processing of step S117 if the number of retries of feeding the medium in step S108 is equal to or greater than a predetermined number. Furthermore, when the drive amount of the feed motor in step S116 becomes equal to or greater than a predetermined amount, the control unit 151 may execute a retry of feeding the medium (re-feeding) in the same manner as the processes of steps S109 to S111.

[0096] FIG. 10 is a graph 1000 showing the relationship between the angle of arm 122 with respect to the mounting surface of mounting table 103 and the pressure applied to pick roller 112, that is, the relationship between the arrangement position of pick roller 112 and the pressure applied to pick roller 112.

[0097] The horizontal axis of FIG. 10 indicates the angle [°] of arm 122 with respect to the placement surface of placement table 103, and the vertical axis indicates the applied pressure [gf] applied to pick roller 112. The larger the angle of arm 122, the higher pick roller 112 is placed. Angle θ1 is the angle at which protrusion 122c of arm 122 changes from a state where it does not contact first pressing member 123 to a state where it contacts first pressing member 123. That is, angle θ1 is the angle between the angle of arm 122 when pick roller 112 is placed at the first position and the angle of arm 122 when pick roller 112 is placed at the second position. Angle θ2 is the angle of arm 122 when pick roller 112 is placed at the second position.

[0098] 10, when the angle of arm 122 is less than angle θ1, that is, when pick roller 112 is located at the first position, only the pressing force of second pressing member 124 is applied to pick roller 112. Therefore, when feeding PPC (plain paper copy) paper or the like, medium feeding device 100 does not press the medium with an extremely large force against pick roller 112, and can prevent the occurrence of medium jams or double feeding.

[0099] Furthermore, medium feeding device 100 can easily change the characteristics of second pressing member 124 for each user by adjusting the pressure applied to pick roller 112 using second pressing member 124. The user can customize second pressing member 124 depending on the application of medium feeding device 100 or the type of medium to be fed. For example, when feeding only thin paper, the user can reduce the pressure applied to pick roller 112 by second pressing member 124, and can appropriately limit the pressure applied to the thin paper by pick roller 112. Therefore, medium feeding device 100 can improve user convenience.

[0100] However, if the force with which the pick roller 112 presses the medium is small, when a medium having a small frictional force between the pick roller 112 and the medium, such as glossy paper, is fed, the medium may slip between the pick roller 112 and the medium, resulting in a failure to feed the medium. When a failure to feed the medium occurs, the medium feeding device 100 raises the pick roller 112 and places it in the second position. As shown in FIG. 10, when the angle of the arm 122 is angle θ2, that is, when the arrangement position of the pick roller 112 is in the second position, the pick roller 112 is subjected to a pressing force by the first pressing member 123 in addition to the pressing force by the second pressing member 124. Therefore, when a failure to feed a medium occurs when a frictional force between the pick roller 112 and the medium fails, the medium feeding device 100 increases the pressing force of the medium by the pick roller 112 to retry feeding the medium, and can feed the medium appropriately.

[0101] In addition, it is desirable that the spring constant of the first pressing member 123 is equal to or less than a predetermined value. In FIG. 10, the applied pressure V1 is an applied pressure that can properly feed glossy paper, and the applied pressure V2 is an applied pressure that is likely to cause a medium jam. As shown in FIG. 10, the applied pressure V2 is greater than the applied pressure V1, but is close to the applied pressure V1. Since the spring constant of the first pressing member 123 is small, the inclination of the graph 1000 when the angle of the arm 122 is greater than the angle θ1 is sufficiently small. Therefore, even if the angle of the arm 122 becomes greater than the angle θ2 due to individual differences in the components such as the pick roller 112, the arm 122, and the first pressing member 123 themselves or the arrangement positions, the applied pressure applied to the pick roller 112 is unlikely to be equal to or greater than the applied pressure V2. Therefore, the medium feeding device 100 can suppress the occurrence of a medium jam due to a positional deviation of the pick roller 112 arranged at the second position caused by individual differences in the components themselves or the arrangement positions of the components.

[0102] In addition, in the medium conveying direction A2, the position of protrusion 122c on arm 122 that abuts against first pressing member 123 is desirably a predetermined distance or more upstream of shaft 122a, which is the swing fulcrum of arm 122. By moving the position on arm 122 where the first pressing force is applied away from the swing fulcrum of arm 122, i.e., away from the position of the center of gravity of arm 122, the ratio of the amount of fluctuation in the first pressing force applied to pick roller 112 to the amount of movement of arm 122 is reduced. Therefore, medium feeding device 100 can suppress the occurrence of medium jams due to misalignment of pick roller 112 arranged at the second position caused by individual differences in the components themselves or the arrangement positions of each component.

[0103] Furthermore, medium feeding device 100 uses second pick roller sensor 126 to detect with high accuracy that pick roller 112 has moved to the second position. This allows medium feeding device 100 to sufficiently reduce the positional deviation amount (angle deviation amount W) of pick roller 112 when pick roller 112 is placed at the second position. Therefore, medium feeding device 100 can prevent the application pressure applied to pick roller 112 from becoming equal to or greater than application pressure V2, causing a medium jam.

[0104] As described above in detail, the medium feeding device 100 raises the placement table 103 when a failure to feed the medium occurs. When the pick roller 112 is disposed at the second position above the first position, the medium feeding device 100 applies a downward pressing force to the pick roller 112, thereby increasing the pressing force of the pick roller 112 against the medium. That is, the medium feeding device 100 changes the magnitude of the pressing force applied to the pick roller 112 in stages when a failure to feed the medium occurs. This allows the medium feeding device 100 to suppress the occurrence of double feeding of the medium when feeding PPC paper or the like, while suppressing the occurrence of slipping of the medium when feeding glossy paper or the like. Therefore, the medium feeding device 100 is capable of appropriately feeding a plurality of types of media.

[0105] The medium feeding device 100 can reduce the frequency with which a user has to reset and re-feed the medium due to a failure in feeding the medium, thereby improving user convenience.

[0106] 11, 12, and 13 are schematic diagrams for explaining a pick roller 112 of a medium feeding device according to another embodiment.

[0107] The medium feeding device according to this embodiment has an arm 222 and a first pressing member 223 instead of the arm 122 and the first pressing member 123.

[0108] The arm 222 has a similar configuration to the arm 122. However, the arm 222 does not have the protrusion 122c, but has a contact portion 222c. The contact portion 222c is provided on the upper end of the arm 222.

[0109] The first pressing member 223 is an example of a pressing member. The first pressing member 223 is a weighted member such as a weight. The first pressing member 223 is disposed above the arm 222 and generates gravity downward. The first pressing member 223 is supported by the frame 102b so as to be swingable so as to be disposed at a position facing the abutment portion 222c. When the first pressing member 223 abuts against the abutment portion 222c, the first pressing member 223 presses the abutment portion 222c downward. Thus, the first pressing member 223 is provided so as to be able to apply a first pressing force downward to the pick roller 112. By using a weighted member as the first pressing member 223, the medium feeding device can apply the first pressing force to the pick roller 112 at a low cost and stably.

[0110] 11, when pick roller 112 is disposed at the initial position, first pressing member 223 does not abut against contact portion 222c and does not apply the first pressing force to pick roller 112. Also, as shown in FIG. 12, when pick roller 112 is disposed at the first position, first pressing member 223 does not abut against contact portion 222c and does not apply the first pressing force to pick roller 112. On the other hand, as shown in FIG. 13, when pick roller 112 is disposed at the second position, first pressing member 223 abuts against contact portion 222c and applies the first pressing force to pick roller 112 via contact portion 222c.

[0111] The medium feeding device according to this embodiment executes the medium reading process shown in Figures 8 and 9, similar to medium feeding device 100. The medium feeding device according to this embodiment also gradually changes the magnitude of the pressing force applied to pick roller 112 when a failure to feed the medium occurs. In particular, by using a weight member as first pressing member 223, the medium feeding device is less susceptible to the effects of changes in the arrangement position of mounting table 103, and can adjust the magnitude of the pressing force applied to pick roller 112 with greater precision.

[0112] As described above in detail, even when a weighted member is used as the first pressing member 223, the medium feeding device is able to appropriately feed a plurality of types of media.

[0113] FIG. 14 is a diagram showing a schematic configuration of a processing circuit 350 of a medium feeding device according to still another embodiment.

[0114] The processing circuit 350 is used in place of the processing circuit 150 of the medium feeding device 100, and executes the medium reading process and the like in place of the processing circuit 150. The processing circuit 350 has a control circuit 351, an image acquisition circuit 352, and the like. Note that each of these components may be composed of an independent integrated circuit, microprocessor, firmware, and the like.

[0115] The control circuit 351 is an example of a control unit, and has the same functions as the control unit 151. The control circuit 351 receives an operation signal from the operation device 105 or the interface device 132. The control circuit 351 also receives a first medium signal, a speed signal, a second medium signal, and a third medium signal from the first medium sensor 111, the speed sensor 113, the second medium sensor 116, and the third medium sensor 119, respectively. The control circuit 351 also receives a first pick roller signal and a second pick roller signal from the first pick roller sensor 125 and the second pick roller sensor 126, respectively. The control circuit 351 controls the first motor 121a and the second motor 131 based on the received signals.

[0116] The image acquisition circuit 352 is an example of an image acquisition section, and has the same function as the image acquisition section 152. The image acquisition circuit 352 acquires an input image from the imaging device 120, and outputs it to the interface device 132.

[0117] As described above in detail, the medium feeding device is now capable of appropriately feeding a plurality of types of media, even when using the processing circuit 350.

[0118] Although the preferred embodiments have been described above, the embodiments are not limited thereto. For example, the medium feeding device 100 may have a plurality of first pressing members 123, and the magnitude of the pressing force applied to the pick roller 112 may be changed in three or more stages according to the arrangement position of the pick roller 112. This allows the medium feeding device 100 to appropriately feed more types of media.

[0119] Also, instead of first pick roller sensor 125 and second pick roller sensor 126, an imaging sensor fixed to second housing 102 may be used to capture an image of pick roller 112 and / or arm 122. In this case, the imaging sensor generates an image of pick roller 112 and / or arm 122, and detects the position of pick roller 112 and / or arm 122 in the generated image using a known image processing technique. Based on the detected position of pick roller 112 and / or arm 122, the imaging sensor generates and outputs a pick roller signal indicating whether pick roller 112 is located at the initial position, the first position, or the second position.

[0120] In this case, control unit 151 acquires a pick roller signal from the imaging sensor in steps S103, S113, S119, and S125 in Fig. 8 and Fig. 9. Control unit 151 determines whether pick roller 112 is disposed at the initial position, the first position, or the second position based on the acquired pick roller signal.

[0121] Alternatively, first pick roller sensor 125 and / or second pick roller sensor 126 may be omitted. In that case, control unit 151 determines whether pick roller 112 is disposed at the initial position, the first position, or the second position, based on the drive amount of first motor 121a. [Explanation of symbols]

[0122] 100 medium feeding device, 103 placement table, 112 pick roller, 123 first pressing member, 124 second pressing member, 125 first pick roller sensor, 126 second pick roller sensor, 151 control unit

Claims

1. A mounting platform that is provided to be raised and on which a medium is placed, A pick roller is positioned above the aforementioned mounting platform, is provided to be able to rise, and feeds the medium placed on the aforementioned mounting platform. A first pressing member that applies a first downward pressing force to the pick roller, A second pressing member that applies a second downward pressing force to the pick roller, The system includes a control unit that, in the event of a medium feeding error, raises the aforementioned platform so as to press the medium placed on the platform toward the pick roller, The first pressing member does not apply a first pressing force to the pick roller when the pick roller is positioned in the first position, and applies a first pressing force to the pick roller when the control unit raises the aforementioned base and the pick roller is positioned in a second position above the first position. The second pressing member applies the second pressing force to the pick roller regardless of whether the pick roller is positioned in the first or second position. A media supply and delivery device characterized by the following features.

2. The media feeding device according to Claim 1, wherein the control unit controls the raising of the aforementioned platform if the leading edge of the medium does not reach a predetermined position within a predetermined time after the start of medium feeding, or if the movement speed during medium feeding is less than or equal to a predetermined speed.

3. The medium feeding device according to claim 1 or 2, wherein the first pressing member is an elastic member.

4. The medium feeding device according to claim 1 or 2, wherein the first pressing member is a weighting member.

5. The system further includes a sensor for detecting the position of the pick roller, The media feeding device according to claim 1 or 2, wherein the control unit stops the stand described above when the pick roller is positioned in the second position or a third position above the second position.

6. A pick roller, which is provided to be able to rise and positioned above a platform on which a medium is placed, feeds the medium placed on the aforementioned platform, The first pressing member applies a first downward pressing force to the pick roller. The second pressing member applies a second downward pressing force to the pick roller. If a media feeding error occurs, the above-described platform is raised so as to press the media placed on the platform toward the pick roller. The first pressing member does not apply a first pressing force to the pick roller when the pick roller is positioned in the first position, and applies a first pressing force to the pick roller when the pick roller is positioned in a second position above the first position due to the rise of the aforementioned support stand. The second pressing member applies the second pressing force to the pick roller regardless of whether the pick roller is positioned in the first or second position. A media supply and delivery method characterized by the following:

7. A control program for a media feeding device comprising: a platform that is raised and on which a medium is placed; a pick roller positioned above the platform and raised, for feeding the medium placed on the platform; a first pressing member that applies a first downward pressing force to the pick roller; and a second pressing member that applies a second downward pressing force to the pick roller, wherein If a media feeding error occurs, the media feeding device is instructed to raise the aforementioned platform so as to press the media placed on the platform toward the pick roller. The first pressing member does not apply a first pressing force to the pick roller when the pick roller is positioned in the first position, and applies a first pressing force to the pick roller when the pick roller is positioned in a second position above the first position due to the rise of the aforementioned support stand. The second pressing member applies the second pressing force to the pick roller regardless of whether the pick roller is positioned in the first or second position. A control program characterized by the following features.

Images