JP6733173B2 - Feeder - Google Patents

Description

The present invention relates to a feeding device that feeds a sheet-shaped medium.

Patent Document 1 describes a feeding device including a paper feeding tray and a feeding unit that feeds a sheet-shaped medium in the paper feeding tray. The feeding unit of the feeding device includes a feeding roller and an arm that rotatably supports the feeding roller and that is swingably supported by the housing via a shaft portion. The feeding roller is always in contact with the medium due to the rotation of the arm as the remaining amount of the medium decreases. Then, as the feeding roller rotates, the sheet-shaped medium is fed from the paper feed tray.

Patent Document 2 describes a remaining amount detection device having an actuator rotatably supported by a housing and two optical sensors. The remaining amount detecting device detects the remaining amount of the medium in the sheet feeding tray by detecting the state of the actuator that rotates according to the remaining amount of the sheet-shaped medium in the sheet feeding tray by two optical sensors. To do.

JP, 2014-118248, A JP-A-5-97278

The inventor of the present application has found that the following problems occur when the remaining amount detecting device described in Patent Document 2 is adopted in the feeding device described in Patent Document 1. The rotation fulcrum of the actuator of the remaining amount detection device is arranged above the uppermost medium in the state where the maximum number of sheets of sheet-shaped medium is accommodated in the paper feed tray. Therefore, if a small-sized actuator having a short length is adopted, the tip of the actuator cannot reach the medium and is separated from the medium when the medium is reduced to some extent, and the remaining amount of the medium cannot be detected. That is, the problem that the remaining amount detectable range of a plurality of media becomes narrow arises. On the other hand, if the range in which the remaining amount can be detected is widened, for example, from the maximum number of stored media to zero, a long actuator is required. Since the actuator rotates depending on the remaining amount of the medium, when the actuator becomes long, the occupied area of the actuator in the feeding device and the space that must be secured for the movement of the actuator become large. As a result, there arises a problem that the feeding device becomes large.

Therefore, an object of the present invention is to provide a feeding device capable of achieving both miniaturization of the device by miniaturization of the actuator and improvement of convenience by expanding the remaining amount detection range of the medium.

The feeding device of the present invention feeds media by rotating a stacking unit capable of stacking a plurality of sheet-shaped media in a stacked state and contacting the media stacked on the stacking unit. Feeding roller, an arm swingable about a first fulcrum, and rotatably supporting the feeding roller, the first fulcrum, and the feeding roller with respect to the first fulcrum. An actuator supported by the arm so as to be swingable about a second fulcrum provided between the tip of the arm and the farthest from the first fulcrum on the same side, and a swinging posture of the actuator are The sensor includes a sensor that outputs a signal for distinguishing between the first posture and the second posture which is different from the first posture. Then, the actuator is in contact with the medium loaded in the loading unit and the loading amount of the medium while the loading amount of the medium in the loading unit changes from the first predetermined amount to the second predetermined amount smaller than the first loading amount. As the load decreases, the actuator swings about the second fulcrum, and the actuator swings while the loading amount of the medium in the loading unit changes from the first predetermined amount to the second predetermined amount. The moving posture is configured to be switched at least once between the first posture and the second posture, and a linear distance from the second fulcrum of the arm to the tip of the arm is equal to the first distance of the actuator. The linear distance from the second fulcrum of the arm to the first fulcrum is longer than the linear distance from the position farthest from the first fulcrum to the second fulcrum, and the linear distance from the position closest to the first fulcrum of the actuator is It is longer than the straight line distance to the second fulcrum .

In another aspect, a feeding device of the present invention is a stacking unit capable of stacking a plurality of sheet-shaped media in a stacked state, and a medium loaded on the stacking unit while rotating in contact with the media. A feeding roller for feeding a sheet, an arm swingable around a first fulcrum, and rotatably supporting the feeding roller, and the first fulcrum and the first fulcrum. An actuator supported on the arm so as to be swingable about a second fulcrum provided on the same side as the feeding roller and farthest from the first fulcrum and the tip of the arm, and the actuator. And a sensor that outputs a signal for distinguishing the swinging posture with respect to the arm from the first posture and the second posture which is different from the first posture. The linear distance from the second fulcrum of the arm to the tip of the arm is longer than the linear distance from the position farthest from the first fulcrum of the actuator to the second fulcrum, The linear distance from the second fulcrum to the first fulcrum is longer than the linear distance from the position closest to the first fulcrum of the actuator to the second fulcrum.
In still another aspect, the feeding device of the present invention comprises a stacking unit capable of stacking a plurality of sheet-shaped media in a stacked state, and rotating by contacting the media stacked on the stacking unit. A feeding roller for feeding a medium, an arm swingable around a first fulcrum and rotatably supporting the feeding roller, and the first fulcrum and the first fulcrum. And an actuator supported by the arm so as to be swingable about a second fulcrum provided on the same side as the feeding roller and farthest from the first fulcrum and the tip of the arm. The actuator outputs a signal for distinguishing the swinging posture of the actuator from the first posture and the second posture different from the first posture, and outputs the second posture, the first posture, and the first posture. A sensor that outputs a signal for distinguishing a third posture that is different from any of the two postures, and an abutting member configured to come into contact with the actuator are provided, and the actuator includes When the loading amount is equal to or more than the first predetermined amount, the loading amount of the medium in the loading unit is maintained at the first posture by being in contact with the medium loaded in the loading unit and the contact member. When it is less than one predetermined amount, it is configured to be separated from the contact member and switched to the second posture, and further, the actuator is configured such that the loading amount of the medium in the loading unit is from the first predetermined amount to the first predetermined amount. The second posture can be switched from the second posture to the third posture while contacting the medium loaded on the loading unit and swinging about the second fulcrum during the decrease to the second predetermined amount smaller than A linear distance from the second fulcrum of the arm to the tip of the arm is longer than a linear distance from a position farthest from the first fulcrum of the actuator to the second fulcrum. The linear distance from the second fulcrum to the first fulcrum is longer than the linear distance from the position closest to the first fulcrum of the actuator to the second fulcrum .

According to the feeding device of the present invention, the position of the second fulcrum of the actuator changes due to the swing of the arm due to the change in the remaining amount of the medium loaded in the stacking unit, and the actuator itself is centered on the second fulcrum. Rock. Therefore, even when using a relatively short and small actuator, it is possible to widen the range of the loading amount of the medium in the loading unit in which the actuator can contact the medium by following the change in the remaining amount of the medium. As a result, the remaining amount of the medium when the swinging posture of the actuator is switched between the first posture and the second posture can be appropriately selected from the wide load range. Therefore, it is possible to achieve both the miniaturization of the device by miniaturization of the actuator and the improvement of convenience by the expansion of the remaining amount detectable range of the medium.

FIG. 1 is a perspective view of a multi-function peripheral that employs a sheet feeding device according to an embodiment of the present invention. FIG. 2 is a schematic side view showing the internal structure of the printer unit shown in FIG. 1. FIG. 3 is a perspective view showing a paper feeding unit. (A) is an explanatory view for explaining a length relationship between an arm main body of the paper feeding unit and two actuators, and (b) is an explanatory view for explaining an arrangement angle of two sensors of the paper feeding unit. Is. It is a schematic plan view of a sensor. FIG. 7A is a schematic diagram showing a positional relationship between two actuators and two sensors when the paper stacking amount of the paper feed tray is a predetermined amount A1, and FIG. It is a schematic side view which shows the positional relationship of two actuators and two sensors at the time of quantity A2. (A) is a schematic diagram showing a positional relationship between two actuators and two sensors in a state where one sheet has been reduced from the predetermined amount A2 in the sheet tray, and (b) is a sheet feeding method. FIG. 6 is a schematic diagram showing a positional relationship between two actuators and two sensors when the sheet stacking amount on the tray is a predetermined amount A3. (A) is a schematic diagram showing a positional relationship between two actuators and two sensors in a state where one sheet has been reduced from the predetermined amount A3 in the sheet tray, and (b) is a sheet feeding method. FIG. 9 is a schematic side view showing a positional relationship between two actuators and two sensors when the sheet stacking amount on the tray is a predetermined amount A4. FIG. 6 is a schematic side view showing the positional relationship between two actuators and two sensors when there is no paper in the paper feed tray. It is a block diagram of a control unit. It is explanatory drawing which shows the remaining amount of paper corresponding to the state of two sensors. FIG. 8 is a plan view of a modified example of the sheet feeding unit of the sheet feeding device according to the embodiment of the present invention when viewed from below.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate. In the following description, the up-and-down direction D1 is defined with reference to the state (state of FIG. 1) in which the multi-function device 10 including the sheet feeding device 20 according to the embodiment of the present invention is installed in a usable state, The front-back direction D2 is defined with the side on which the opening 13 is provided as the front side (front side), and the left-right direction D3 is defined when the multifunction peripheral 10 is viewed from the front side (front side). Note that the present invention can be realized regardless of the number of actuators included in the feeding device, but here, as an example, a feeding device including two actuators will be described.

[Overall Structure of Multifunction Device 10]
As shown in FIG. 1, the multi-function device 10 has a substantially rectangular parallelepiped shape, and a printer unit 11 is provided at the bottom. The multi-function device 10 has various functions such as a facsimile function and a print function. The multi-function device 10 has a print function of recording an image on one side of a sheet 12 (sheet-shaped medium: see FIG. 2) by an inkjet method. The multifunction device 10 may record images on both sides of the paper 12. A display unit 150 is provided in front of the upper surface of the multi-function device 10. The display 150 displays the state of the multifunction device 10 (for example, the remaining amount of paper).

As shown in FIG. 2, the printer unit 11 includes a housing 11 a, a transport device 1 that transports the paper 12 inside the multifunction machine 10, a recording unit 40, a control unit 180, and the like. The housing 11a is a main body frame of the printer unit 11, and houses the transport device 1, the recording unit 40, and the control unit 180 as illustrated in FIG. The transport device 1 transports the paper 12 inside the multifunction peripheral 10. The transport device 1 includes a sheet feeding device 20, a platen 42, a transport roller pair 50, and a discharge roller pair 60, which will be described later.

The sheet feeding device 20 picks up the sheet 12 from the sheet feeding tray 21 and feeds the sheet 12 to the conveyance path 35. The conveyance roller pair 50 conveys the paper 12 fed by the paper feed device 20 to the conveyance path 35 to the downstream side of the conveyance direction 15 indicated by the dashed-dotted line arrow in FIG. 2, that is, to the front. The platen 42 supports the sheet 12 conveyed by the pair of conveying rollers 50 from below. The recording unit 40 records an image by ejecting ink droplets onto the paper 12 supported by the platen 42. The discharge roller pair 60 conveys the paper 12 on which the image is recorded by the recording unit 40 to the front and discharges it to the discharge tray 22.

[Paper feeder 20]
Next, the sheet feeding device 20 will be described below with reference to FIGS. As shown in FIG. 2, the paper feeding device (feeding device) 20 has a paper feeding tray 21 and a paper feeding unit 70. The paper feed unit 70 picks up the paper 12 from the paper feed tray 21 and feeds the paper 12 to the transport path 35. The paper feed unit 70 in the present embodiment feeds the paper 12 backward.

As shown in FIG. 1, an opening 13 is formed on the front surface of the printer unit 11. The paper feed tray (stacking unit) 21 is supported by the housing 11 a through the opening 13 so that it can be inserted and removed in the front-rear direction D2. The paper feed tray 21 accommodates the plurality of papers 12 by stacking the plurality of papers 12 on the bottom surface 21a thereof in a stacked state. A discharge tray 22 is arranged above the paper feed tray 21. The discharge tray 22 moves together with the paper feed tray 21. The discharge tray 22 supports the paper 12 on which an image is recorded by the recording unit 40 and which is discharged by the discharge roller pair 60.

[Paper feeder 70]
As shown in FIG. 2, the paper feeding unit 70 is provided on the upstream side in the transport direction 15 from the transport path 35, above the paper feeding tray 21, and below the recording unit 40. As shown in FIGS. 2 and 3, the paper feeding unit 70 includes a paper feeding roller 71, an arm 72, a transmission mechanism 73, two actuators 74 and 75, and two sensors 76 and 77.

As shown in FIG. 3, the arm 72 has an arm body 72a and a support frame 72b integrated with the arm body 72a. As shown in FIG. 2, when the arm main body 72a is viewed from left to right in the left-right direction D3 with a support shaft 79 (first fulcrum) provided at the front end portion in the front-rear direction D2 as the center. Further, it is supported by the housing 11a so as to be swingable in the direction of arrow E1 (counterclockwise) and in the direction of arrow E2 (clockwise). Accordingly, the arm 72 is also configured to be swingable in the arrow E1 direction and the arrow E2 direction with respect to the housing 11a. The support shaft 79 is fixed to the housing 11a and is arranged above the paper feed tray 21 in the vertical direction D1. The arm main body 72a rotatably supports the paper feed roller 71 at a tip end portion thereof located rearward in the front-rear direction D2, and due to its own weight, the arm main body 72a moves downward in an arrow E1 direction (counterclockwise direction in FIG. 1). Being energized. As a result, in the state where the paper feed tray 21 is attached to the housing 11 a, the paper feed roller 71 can contact the paper 12 stacked on the paper feed tray 21.

It should be noted that the arm 72 is pivotally engaged with the side wall of the paper feed tray 21 when the paper feed tray 21 is inserted into or removed from the housing 11a, thereby rotating the arm 72 to support the entire arm 72. A retracting member (not shown) for temporarily raising and retracting to the same level as the shaft 79 is provided. As a result, when the paper feed tray 21 in which the maximum amount of paper 12 is stored is inserted into or removed from the housing 11a, the paper 12 in the paper feed tray 21, the paper feed roller 71, and the two actuators 74 and 75 are Does not interfere with each other, and the insertion/removal operation of the paper feed tray 21 can be smoothly performed.

As shown in FIG. 3, the transmission mechanism 73 has a plurality of gears 73a rotatably supported in the arm body 72a about a rotation axis (not shown) along the left-right direction D3. Although four gears 73a are shown in FIG. 3, one gear 73a (not shown in FIG. 3) is provided in the tip portion of the arm body 72a and between a pair of rollers 71a described later. Has been. The plurality of gears 73a are arranged in mesh with each other. Then, the driving force of the sheet feeding motor 71M (see FIG. 9) is transmitted to the gear 73a arranged at the base end of the arm body 72a, whereby the plurality of gears 73a rotate.

The paper feed roller (feed roller) 71 has a pair of rollers 71a. The pair of rollers 71a is arranged so as to sandwich the inside of the tip portion of the arm body 72a in the left-right direction D3. The pair of rollers 71a is fixed to a rotation shaft of a gear 73a (not shown) provided in the tip of the arm body 72a. Accordingly, the plurality of gears 73a of the transmission mechanism 73 are rotated by the driving force of the sheet feeding motor 71M, and the sheet feeding roller 71 is also rotated. By the rotation of the paper feed roller 71, the paper 12 in the paper feed tray 21 is fed toward the transport path 35.

As shown in FIG. 3, the support frame 72b has a substantially box shape, and is provided on the left side wall of the arm body 72a in the left-right direction D3. Two actuators 74 and 75 and two sensors 76 and 77 are provided in the support frame 72b. That is, the support frame 72b is a frame for supporting the actuators 74 and 75 and the sensors 76 and 77. The support frame 72b is provided with two support shafts 72b1 and 72b2 extending in the left-right direction D3. The support shaft 72b1 is arranged between the support shaft 79 and the support shaft 72b2, as shown in FIG. 4(a). More specifically, the support shaft 72b1 is disposed between the support shaft 79 and the support shaft 72b2 in the vertical direction D1, and is also disposed between the support shaft 79 and the support shaft 72b2 in the front-rear direction D2. There is. In other words, the support shaft 72b2 is farther from the support shaft 79 than the support shaft 72b1. The bottom 72b3 of the support frame 72b is formed with two openings (not shown) penetrating in the vertical direction D1. These openings are opposed to the actuators 74 and 75 in the vertical direction D1. As a result, the actuators 74 and 75 can move in and out of the support frame 72b through the openings, and can come into contact with the paper 12.

As shown in FIGS. 3 and 4, the actuator 74 is supported by the support frame 72b so as to be swingable about a support shaft 72b1 (second support point). The actuator 74 has a front portion 74a located closer to the front in the front-rear direction D2, a rear portion 74b located closer to the rear, and a connecting portion 74c connecting the front portion 74a and the rear portion 74b. Both the front part 74a and the rear part 74b extend along a direction orthogonal to the support shaft 72b1. The connecting portion 74c extends in the left-right direction D3. The front portion 74a and the rear portion 74b are arranged so as to be offset from each other in the left-right direction D3. The actuator 74 is supported by the support shaft 72b1 at the lower portion in the up-down direction D1 at the central portion of the rear portion 74b in the extending direction. A coil spring 74d (biasing member) is provided on the outer periphery of the support shaft 72b1 as shown in FIG. 4(a). One end of the coil spring 74d is engaged with the rear portion 74b and the other end is engaged with the support frame 72b. As shown in FIG. 4A, when viewed from left to right in the left-right direction D3. The coil spring 74d biases the actuator 74 counterclockwise, that is, in the direction of arrow F1.

As shown in FIG. 4A, a contact portion 74e where the actuator 74 and the paper 12 stacked on the paper feed tray 21 come into contact is a lower portion of the rear portion 74b in the vertical direction D1, and with respect to the front-back direction D2. It is located farther from the support shaft 79 than the support shaft 72b1. From this point on, the actuator 74 will continue to swing in the same direction as the arm 72. Specifically, when the number of sheets 12 in the sheet feed tray 21 decreases, the arm 72 swings in the direction of arrow E1. At this time, the actuator 74 also swings in the same direction (arrow F1).

The front portion 74a of the actuator 74 is provided with an interference portion 74a1 and an abutting portion 74a2. The interference portion 74a1 is formed on the front side of the front portion 74a in the front-rear direction D2, and is configured to interfere with the sensor 76 as described later. The contact portion 74a2 projects upward in the vertical direction D1 from the interference portion 74a1 in the rearward direction in the front-rear direction D2 with respect to the interference portion 74a1, and contacts the frame 11a1 (contact member) of the housing 11a described later. It is configured to be possible.

As shown in FIG. 4A, the actuator 74 has a shorter length than the arm body 72a. Specifically, a virtual straight line from the support shaft 72b1 of the arm body 72a to the tip of the arm body 72a (the tip of the arm 72 that is on the same side as the paper feed roller 71 with respect to the support shaft 79 and is farthest from the support shaft 79). The distance L1a is longer than the distance of the virtual straight line L1b from the position farthest from the support shaft 79 of the actuator 74 to the support shaft 72b1. Further, the distance of the virtual straight line L1c from the support shaft 72b1 of the arm body 72a to the support shaft 79 is longer than the distance of the virtual straight line L1d from the position closest to the support shaft 79 of the actuator 74 to the support shaft 72b1.

As shown in FIGS. 3 and 4A, the actuator 75 is supported by the support frame 72b so as to be swingable around a support shaft 72b2 (second support point). The actuator 75 has a front portion 75a located closer to the front in the front-rear direction D2, a rear portion 75b located closer to the rear, and a connecting portion 75c connecting the front portion 75a and the rear portion 75b. The rear part 75b extends in a direction orthogonal to the support shaft 72b2. The connecting portion 75c extends in the left-right direction D3 from a portion slightly forward of the center of the rear portion 75b in the extending direction. The front part 75a extends forward from the right end of the connecting part 75c. In this way, the actuator 75 is also arranged such that the front portion 75a and the rear portion 75b are displaced in the left-right direction D3. The front portion 75a has an interference portion 75a1 capable of interfering with the sensor 77 as described later. The actuator 75 is supported by the support shaft 72b2 at the rear end portion of the rear portion 75b. As a result, the actuator 75 is biased by its own weight in the clockwise direction in FIG. 4, that is, in the direction of arrow F2.

As shown in FIG. 4A, a contact portion 75e where the actuator 75 and the paper 12 stacked on the paper feed tray 21 come into contact is a lower portion in the vertical direction D1 at the center of the rear portion 75b, and is in the front-back direction. With respect to D2, the support shaft 72b2 is located farther from the support shaft 79 than the contact point 75e. The actuator 75 will continue to swing in the direction opposite to the arm 72. Specifically, when the number of sheets 12 in the sheet feed tray 21 decreases, the arm 72 swings in the direction of arrow E1. At this time, the actuator 75 swings in the direction of arrow F2.

The actuator 75 is also configured to have a length shorter than that of the arm body 72a, as shown in FIG. That is, a virtual straight line L2a from the support shaft 72b2 of the arm body 72a to the tip of the arm body 72a (the tip of the arm 72 on the same side as the paper feed roller 71 with respect to the support shaft 79 and farthest from the support shaft 79). The distance is longer than the distance of the virtual straight line L2b from the position farthest from the support shaft 79 of the actuator 75 to the support shaft 72b2. The distance of the virtual straight line L2c from the support shaft 72b2 of the arm body 72a to the support shaft 79 is longer than the distance of the virtual straight line L2d from the position closest to the support shaft 79 of the actuator 75 to the support shaft 72b2. In this way, the actuator 75 is configured so that its length is shorter than that of the arm body 72a.

Further, the actuator 75 is arranged side by side with the actuator 74 along the left-right direction D3. In other words, the two actuators 74 and 75 are arranged at substantially the same position in the front-rear direction D2 (the feeding direction of the paper 12 by the paper feed roller 71). Therefore, the size of the paper feeding device 20 in the front-rear direction D2 can be reduced.

As shown in FIG. 4A, in the actuator 74, the interference portion 74a1 (interference point) and the contact point 74e are located on the opposite sides of the support shaft 72b1. Further, in the actuator 75, the interference portion 75a1 (interference point) and the support shaft 72b2 are located on the opposite sides of the contact point 75e. As described above, the two actuators 74 and 75 swing in the opposite directions (the actuator 74 is an arrow F1 and the actuator 75 is an arrow F2) as the sheets 12 stacked on the paper feed tray 21 decrease.

As shown in FIGS. 3 and 4, the two sensors 76 and 77 are arranged at slightly different positions in the left-right direction D3 and the up-down direction D1, but are arranged at substantially the same position in the front-rear direction D2. Therefore, the two sensors 76 and 77 can be arranged at positions close to each other. For this reason, it becomes easy to attach to one wiring board 78 provided on the support frame 72b. By mounting the two sensors 76 and 77 on the single substrate 78 in this manner, it is possible to reduce the number of components and the manufacturing cost as compared with the case where a wiring substrate is provided for each sensor. Further, since the two sensors 76 and 77 are supported by the support frame 72b that supports the actuators 74 and 75 via the wiring board 78, the interference portion 74a1 between the sensor 76 and the actuator 74, and the sensor 77 and the actuator. It becomes easy to align the 75 with the interference portion 75a1. Therefore, it is possible to detect the remaining amount with high accuracy.

As shown in FIG. 5, the two sensors 76 and 77 respectively include light emitting elements 76a and 77a such as light emitting diodes (LEDs), light receiving elements 76b and 77b such as phototransistors, and housings 76c and 77c. Type optical sensor. Since these two sensors 76 and 77 have the same configuration, the sensor 76 will be described.

The light emitting element 76a and the light receiving element 76b are each surrounded by a housing 76c. The housing 76c has a U-shaped planar shape as shown in FIG. The light emitting element 76a is provided on the right side wall portion of the housing 76c, and is arranged so that light can be emitted to the left. The light receiving element 76b is provided on the left side wall portion of the housing 76c, and is arranged so as to be able to receive the light emitted from the light emitting element 76a. In this way, the light emitting element 76a and the light receiving element 76b are arranged to face each other in the left-right direction D3 at a predetermined interval in the U-shaped casing 76c. The interference portion 74a1 of the actuator 74 can enter the space (light path of the sensor 76) between the light emitting element 76a and the light receiving element 76b of the sensor 76. When the interference part 74a1 enters the optical path of the sensor 76 and blocks the light from the light emitting element 76a to the light receiving element 76b (that is, when the sensor 76 interferes with the actuator 74), the sensor 76 is in the "ON state", and the sensor 76 is controlled. A signal indicating the ON state is output to the unit 180. On the other hand, when the interference section 74a1 retracts from the optical path of the sensor 76 and the light receiving element 76b receives the light from the light emitting element 76a, the sensor 76 is in the "OFF state", and the sensor 76 is in the OFF state. Output the signal shown.

The sensor 77, like the sensor 76, has a light emitting element 77a and a light receiving element 77b. The light emitting element 77a and the light receiving element 77b are also arranged to face each other in the left-right direction D3 at a predetermined interval in the U-shaped casing 77c. The interference portion 75a1 of the actuator 75 can enter the space (light path of the sensor 77) between the light emitting element 77a and the light receiving element 77b of the sensor 77. When the interference part 75a1 enters the optical path of the sensor 77 and blocks the light from the light emitting element 77a to the light receiving element 77b (that is, when the sensor 77 interferes with the actuator 75), the sensor 77 is turned on and the sensor 77 controls. A signal indicating the ON state is output to the unit 180. On the other hand, when the interference section 75a1 is retracted from the optical path of the sensor 77 and the light receiving element 77b receives the light from the light emitting element 77a, the sensor 77 is in the "OFF state", and the sensor 77 is in the OFF state. Output the signal shown.

In this way, the sensor 76 takes the “ON state” when it interferes with the actuator 74, the “OFF state” when it does not interfere with the actuator 74, and the sensor 77 the “ON state” when it interferes with the actuator 75. When it does not interfere with the actuator 75, it takes the “OFF state”. The sensors 76 and 77 output different signals depending on whether or not they interfere with the actuators 74 and 75.

As shown in FIG. 4B, the two sensors 76, 77 and the two support shafts 72b1, 72b2 are arranged so that the angle θ1 and the angle θ2 are different from each other (angle θ1>angle θ2). As for the angle θ1, a virtual line segment L3 passing through the light emitting element 76a (or the light receiving element 76b) of the sensor 76 and the support shaft 72b1 is a virtual horizontal plane H1 passing through the support shaft 72b1 (the paper 12 stacked on the paper feed tray 21 Is a plane parallel to the surface of the). The angle θ2 is an angle formed by a virtual line segment L4 passing through the light emitting element 77a (or the light receiving element 77b) of the sensor 77 and the support shaft 72b2 with a virtual horizontal plane H2 passing through the support shaft 72b2. Thus, it is possible to easily realize a configuration in which the state of the sensor 76 is switched and the state of the sensor 77 is switched and the stacking amounts of the sheets 12 are different from each other.

As shown in FIG. 4B, the two support shafts 72b1 and 72b2 supporting the actuators 74 and 75 are displaced in the vertical direction D1 (direction orthogonal to the surface of the paper 12 stacked on the paper feed tray 21). It is arranged. As a result, it is possible to easily realize a configuration in which the loading amount of the paper 12 is different from each other when the sensor 76 is switched between the ON state and the OFF state and the sensor 77 is switched between the ON state and the OFF state.

Here, switching of the states of the two sensors 76 and 77 associated with the operation of the two actuators 74 and 75 will be described below with reference to FIGS. 6 to 9.

The paper feed tray 21 in the present embodiment can stack, for example, up to 250 sheets of A4 size plain paper. The arm 72 swings counterclockwise in the figure by one sheet at a time as the remaining amount of the paper 12 decreases so that the paper feed roller 71 is arranged at a position where the paper feed roller 71 is in contact with the uppermost paper 12. To do. As shown in FIG. 6A, when a predetermined amount A1 (third predetermined amount of the actuator 74) of paper 12 corresponding to 250 sheets is stacked on the paper feed tray 21, the contact portion of the actuator 74 is 74a2 contacts the frame 11a1 that supports the inner guide member 19, and the actuator 74 is maintained in a state where the contact point 74e is separated from the sheet 12. Further, the actuator 74 at this time is in a state where the interference portion 74a1 is retracted downward from the optical path of the sensor 76, that is, in a non-interference state. That is, the sensor 76 is in the “OFF state (second state)”. On the other hand, when the loading amount is the predetermined amount A1 (first predetermined amount of the actuator 75), the actuator 75 does not come into contact with the frame 11a1 and is attached by its own weight in the clockwise direction in the figure (direction of arrow F2 in FIG. 4). Since it is biased, the contact point 75e comes into contact with the uppermost sheet 12. At this time, the actuator 75 is in a state where the interference portion 75a1 is retracted upward from the optical path of the sensor 77, that is, a non-interference state. That is, the sensor 77 is in the “OFF state (second state)”.

The actuator 74 is entirely displaced downward by the displacement of the support shaft 72b1 accompanying the swing of the arm 72. The contact portion 74a2 of the actuator 74 has a predetermined amount A2 (see FIG. 6A) corresponding to the first predetermined number (for example, 150) of the sheet stacking amount of the sheet feed tray 21 from the predetermined amount A1 (see FIG. 6A). (See (b)) (For the first predetermined amount of the actuator 74), it is in contact with the frame 11a1. Therefore, the actuator 74 swings counterclockwise in the figure (direction of arrow F1 in FIG. 4) while its free swing is restricted. Then, when the sheet stacking amount of the sheet feed tray 21 reaches the predetermined amount A2, the contact portion 74e contacts the sheet 12. When the amount of sheets stacked on the sheet feed tray 21 reaches the predetermined amount A2, the actuator 74 remains in a state (non-interference state) in which the interference portion 74a1 is retracted downward from the optical path of the sensor 76. That is, the sensor 76 is maintained in the "OFF state". In this way, the actuator 74 ensures that the contact portion 74a2 contacts the frame 11a1 and the state of the sensor 76 is set to the “OFF state” when the sheet stacking amount of the sheet feed tray 21 is equal to or smaller than the predetermined amount A1 and equal to or larger than the predetermined amount A2. Can be maintained. On the other hand, the actuator 75 is in the opposite direction to the arm 72 while the actuator 75 is in contact with the paper 12 and the entire shaft is displaced downward due to the displacement of the support shaft 72b2 accompanying the swing of the arm 72, that is, in the figure. Swing clockwise. When the number of sheets stacked on the sheet feed tray 21 reaches the predetermined amount A2, the actuator 75 remains in a state (non-interference state) in which the interference portion 75a1 is retracted upward from the optical path of the sensor 77. That is, the sensor 77 is maintained in the "OFF state". In this way, when the paper stacking amount of the paper feed tray 21 is equal to or larger than the predetermined amount A2, the actuators 74 and 75 have a swinging posture (hereinafter, referred to as “first posture B1”) in which the corresponding sensors 76 and 77 are in the “OFF state”. , C1”) for each arm 72.

Subsequently, when the remaining amount of the paper 12 further decreases, the actuator 74 is entirely displaced further downward due to the displacement of the support shaft 72b1 accompanying the swing of the arm 72. As shown in FIG. 7A, the contact portion 74a2 of the actuator 74 has a frame 11a1 when the sheet stacking amount of the sheet feed tray 21 is less than a predetermined amount A2, that is, when one sheet 12 is reduced from the predetermined amount A2. Stay away from. Therefore, when the stacking amount of sheets on the sheet feed tray 21 becomes less than the predetermined amount A2, the actuator 74 swings counterclockwise in the figure in a state where the regulation by the contact portion 74a2 is released. The actuator 74 is in a state (interference state) in which the interference portion 74a1 has entered the optical path of the sensor 76 when the number of sheets stacked on the sheet feed tray 21 is smaller than the predetermined amount A2 by one sheet 12. That is, the sensor 76 is switched to the "ON state". Then, in the actuator 74, while the sheet stacking amount of the sheet feed tray 21 is reduced to a predetermined amount A3 (see FIG. 7B) corresponding to the second predetermined number (for example, 50 sheets), the interference unit 74a1 is operated by the sensor 76. Remains in the optical path (interference state). That is, the sensor 76 is maintained in the "ON state". On the other hand, the actuator 75 oscillates clockwise in the drawing while the entire body is further displaced downward due to the displacement of the support shaft 72b2 accompanying the oscillation of the arm 72. In the actuator 75, the interference portion 75a1 of the actuator 75 reduces the optical path of the sensor 77 while the stacking amount of sheets on the sheet feeding tray 21 decreases from a predetermined amount A2 (see FIG. 6B) to a predetermined amount A3 (see FIG. 7B). It remains in a state of being retracted upward from (non-interference state). That is, the sensor 77 is maintained in the "OFF state". In this way, when the paper stacking amount of the paper feed tray 21 is less than the predetermined amount A2 and not less than the predetermined amount A3, the actuator 74 swings the sensor 76 to the “ON state” (hereinafter referred to as “second posture B2”). To the arm 72. On the other hand, at this time, the actuator 75 remains in the first posture C1 in which the sensor 77 is in the “OFF state”, as in the case where the sheet stacking amount of the sheet feed tray 21 is equal to or larger than the predetermined amount A2.

Then, when the remaining amount of the paper 12 further decreases, the actuator 74 swings counterclockwise in the drawing while the entire body is further displaced downward due to the displacement of the support shaft 72b1 accompanying the swing of the arm 72. The actuator 74 has a predetermined amount A3 (see FIG. 7B) from the predetermined amount A3 (see FIG. 7B) of the sheet stacking tray 21, and a predetermined amount A4 (see FIG. 8B) corresponding to one remaining sheet (second of the actuator 74). The interference portion 74a1 remains in the state of entering the optical path of the sensor 76 (interference state) while decreasing to a predetermined amount). That is, the sensor 76 is maintained in the "ON state". On the other hand, the actuator 75 further swings clockwise in the drawing as the number of sheets 12 decreases. The actuator 75 has its interference portion 75a1 in a state in which one sheet 12 has decreased from the state where the sheet stacking amount of the sheet feed tray 21 shown in FIG. 7B is A3 (see FIG. 8A). Enters the optical path of the sensor 77 (interference state). That is, the sensor 77 is switched to the “ON state”. Then, the actuator 75 causes the interference section 75a1 to enter the optical path of the sensor 77 while the sheet stacking amount of the sheet feed tray 21 decreases to a predetermined amount A4 (see FIG. 8B) (second predetermined amount of the actuator 75). It remains as it is (interference state). That is, the sensor 77 is maintained in the "ON state". In this way, when the paper stacking amount of the paper feed tray 21 is less than the predetermined amount A3 and the predetermined amount A4 or more, the actuator 74 detects the sensor as in the case where the paper stacking amount of the paper feeding tray 21 is less than the predetermined amount A2 and the predetermined amount A3 or more. The second posture B2 in which 76 is in the “ON state” remains as it is. On the other hand, the actuator 75 is configured to take a swinging posture (hereinafter, referred to as “second posture C2”) in which the sensor 77 is in the “ON state” with respect to the arm 72.

When the paper 12 in the paper feed tray 21 is exhausted, as shown in FIG. 9, the arm 72 further swings counterclockwise in the drawing, and the paper feed roller 71 contacts the bottom surface 21 a of the paper feed tray 21. The actuator 74 is further swung counterclockwise in the figure while being displaced downward as a whole, and the contact portion 74e falls into the hole 21b formed in the bottom surface 21a. At this time, the actuator 74 is in a state (non-interference state) in which the interference portion 74a1 is retracted upward from the optical path of the sensor 76. That is, the sensor 76 is switched to the “OFF state”. On the other hand, the actuator 75 is further swung clockwise in the drawing while being displaced downward as a whole, and the contact point 75e contacts the bottom surface 21a. At this time, the actuator 75 remains in a state (interference state) in which the interference portion 75a1 enters the optical path of the sensor 77. That is, the sensor 77 is maintained in the "ON state". In this way, when there is no sheet 12 in the sheet feed tray 21, the actuator 74 takes a swinging posture (hereinafter, referred to as “third posture B3”) with respect to the arm 72 in which the sensor 76 is in the “ON state”. Is configured. As described above, in the first posture B1 and the third posture B3, the position of the interference portion 74a1 with respect to the sensor 76 is opposite. On the other hand, at this time, the actuator 75 is still in the second posture C2 in which the sensor 77 is in the “ON state”, as in the case where the sheet stacking amount of the sheet feed tray 21 is less than the predetermined amount A3 and the predetermined amount A4 or more. When the number of sheets 21 in the sheet feed tray 21 is changed from 1 to 0, the actuator 74 switches the swinging posture from the second posture B2 to the third posture B3, and only the sensor 76 is changed from the “ON state” to the “OFF state”. It switches to. Therefore, it is possible to reliably detect the state where the number of the sheets 12 in the sheet feeding tray 21 is zero.

The first postures B1 and C1 in this embodiment correspond to the “first posture” of the present invention. The second postures B2 and C2 in the present embodiment correspond to the "second posture" of the present invention.

As described above, in the embodiment, the actuator 74 causes the paper feed tray 21 to move while the paper loading amount of the paper feed tray 21 changes from the predetermined amount A2 (first predetermined amount) to the predetermined amount A4 (second predetermined amount). It swings counterclockwise while contacting the loaded sheets. The state of the sensor 76 is switched when the stacking amount of sheets decreases from the predetermined amount A2 by one sheet during this period. That is, with respect to the actuator 74, the swinging posture is between the first posture B1 and the second posture B2 while the loading amount of the medium in the loading unit changes from the first predetermined amount to the second predetermined amount according to the present invention. The configuration that can be switched by is established. On the other hand, the actuator 75 detects the number of sheets stacked on the sheet feed tray 21 while the sheet stacking amount on the sheet feed tray 21 changes from a predetermined amount A1 (first predetermined amount) to a predetermined amount A4 (second predetermined amount). Swing clockwise while touching. The state of the sensor 77 is switched when the stacking amount of sheets decreases from the predetermined amount A3 by one sheet during this period. That is, also with respect to the actuator 75, the swinging postures of the first posture C1 and the second posture C2 according to the present invention while the stacking amount of the medium in the stacking unit changes from the first predetermined amount to the second predetermined amount. The structure that can be switched between is established.

[Transport path 35]
As shown in FIG. 2, the transport path 35 extends from the rear end of the paper feed tray 21. The transport path 35 includes a curved transport path 33 and a straight transport path 34. The curved conveyance path 33 extends while curving with the rear side of the printer unit 11 as the curved outer side and the front side as the curved inner side. The straight transport path 34 extends in the front-rear direction D2. The paper 12 supported by the paper feed tray 21 is conveyed so as to make a U-turn from the lower side to the upper side of the curved conveyance path 33, and then is conveyed forward through the linear conveyance path 34 to be guided to the recording section 40. The sheet 12 on which the image recording has been performed by the recording unit 40 is further transported forward in the straight transport path 34 and discharged to the discharge tray 22.

The curved conveyance path 33 is formed by an outer guide member 18 and an inner guide member 19 that are opposed to each other with a predetermined distance. The outer guide member 18 and the inner guide member 19 are supported by the housing 11a. The inner guide member 19 is fixed to the frame 11a1 arranged below the conveying roller pair 50. The outer guide member 18 has a guide surface 18 a that forms the curved outer side of the curved conveyance path 33. The inner guide member 19 has a guide surface 19 a that forms a curved inner side of the curved conveyance path 33. The linear transport path 34 is formed by a recording unit 40 and a platen 42 that face each other with a predetermined distance therebetween.

[Conveying roller pair 50]
As shown in FIG. 2, the conveyance roller pair 50 is composed of a pair of rollers 52 and 53, and is arranged on the upstream side in the conveyance direction 15 with respect to the recording unit 40. The roller 52 is disposed below the roller 53, and contacts the lower surface of the sheet 12 guided from the curved transport path 33 to the straight transport path 34. The roller 52 is a drive roller which is rotated by being applied with a driving force from the carry motor 50M (see FIG. 10). The roller 53 is arranged so as to face the roller 52, and contacts the upper surface of the sheet 12. The roller 53 follows along with the rotation of the roller 52. The roller 52 and the roller 53 cooperate with each other to nip the sheet 12 in the up-down direction D1 and convey the sheet 12 in the conveyance direction 15.

[Discharge roller pair 60]
As shown in FIG. 2, the discharge roller pair 60 is composed of a pair of rollers 62 and 63, and is arranged downstream of the recording unit 40 in the transport direction 15. The roller 62 is disposed below the roller 63, and contacts the lower surface of the sheet 12 conveyed through the linear conveyance path 34. The roller 62 is a drive roller that is rotated by being applied with a driving force from the carry motor 50M. The roller 63 is arranged so as to face the roller 62, and contacts the upper surface of the paper 12. The roller 63 is a spur roller that rotates along with the rotation of the roller 62. The roller 62 and the roller 63 cooperate to nip the sheet 12 in the up-down direction D1 and convey the sheet 12 in the conveyance direction 15. As a result, the paper 12 is conveyed toward the opening 13 located on the downstream side in the conveyance direction 15 from the discharge roller pair 60, and is discharged onto the discharge tray 21.

[Platen 42]
As shown in FIG. 2, the platen 42 is provided below the linear transport path 34 and between the transport roller pair 50 and the discharge roller pair 60. The platen 42 is a plate-shaped member that is arranged so as to face the recording unit 40 in the up-down direction D1 and supports the sheet 12 conveyed through the linear conveyance path 34 from below.

[Recording unit 40]
As shown in FIG. 2, the recording unit 40 is arranged above the linear transport path 34 and at a position facing the platen 42 in the vertical direction D1. The recording unit 40 has a carriage 41, a recording head 38, and a drive mechanism 40a (see FIG. 10). The carriage 41 is supported by two guide rails 45 and 46. The two guide rails 45 and 46 are arranged apart from each other in the front-rear direction D2 and extend in the left-right direction D3. The carriage 41 is arranged so as to straddle the two guide rails 45 and 46. Further, the drive mechanism 40a has a carriage drive motor 40M, and reciprocates the carriage 41 in the left-right direction D3, which is the main scanning direction, along the two guide rails 45 and 46 under the control of the control unit 180. The recording head 38 is mounted on the carriage 41. The recording head 38 ejects ink supplied from an ink cartridge (not shown) from nozzles 39 provided on the lower surface. That is, while the carriage 41 is moving in the left-right direction D3, ink droplets are ejected from the nozzles 39 of the recording head 38 toward the platen 42, so that an image is formed on the upper surface of the paper 12 supported by the platen 42. Will be recorded.

[Control unit 180]
As shown in FIG. 10, the control unit 180 includes a CPU (Central Processing Unit) 181, a ROM (Read Only Memory) 182, a RAM (Random Access Memory) 183, an ASIC (Application Specific Integrated Circuit) 184, and the like. Together, they control the operations of the carriage drive motor 40M, the recording head 38, the paper feed motor 71M, the conveyance motor 50M, the display unit 150, and the like. For example, the control unit 180 controls the recording head 38, the carriage drive motor 40M, the paper feed motor 71M, the conveyance motor 50M, and the like based on the recording command transmitted from an external device such as a PC, and the image or the like on the paper 12. To record.

Further, the ROM 182 stores four types of combinations of the states of the two sensors 76 and 77. These four types of combinations correspond to the four remaining paper amount states. Specifically, as shown in FIG. 11, when the sensor 76 is in the OFF state and the sensor 77 is in the ON state, it corresponds to the absence of paper, and when the sensor 76 is in the ON state and the sensor 77 is in the ON state, the near empty state is present. When the sensor 76 is in the ON state and the sensor 77 is in the OFF state, it corresponds to the stacking of sheets, and when the sensor 76 is in the OFF state and the sensor 77 is in the OFF state, it corresponds to the large sheet stacking. Then, the control unit 180 causes the display unit 150 to display the remaining amount of paper based on the signals from the sensors 76 and 77.

Although FIG. 10 shows one CPU 181 and one ASIC 184, the control unit 180 may include only one CPU 181, and the one CPU 181 may collectively perform necessary processing. However, a plurality of CPUs 181 may be included, and the plurality of CPUs 181 may share necessary processing. Further, the control unit 180 may include only one ASIC 184 and collectively perform the processing required by this one ASIC 184, or may include a plurality of ASICs 184 and share the processing required by the plurality of ASICs 184. It may be performed by doing.

Subsequently, the detection of the remaining amount of paper will be described below. As shown in FIGS. 6A and 6B, when the paper stacking amount of the paper feed tray 21 is equal to or larger than the predetermined amount A2, the contact portion 74a2 of the actuator 74 contacts the frame 11a1. Take the non-interference state. At this time, the actuator 75 is also in the non-interference state. Both of the two sensors 76 and 77 are turned off, and the control section 180 outputs signals indicating the off state. As a result, the control unit 180 determines, based on the signals from the two sensors 76 and 77, that the sheet 12 in the paper feed tray 21 is in the large stack state indicating that the remaining amount of the sheets 12 is sufficient. Then, the control unit 180 causes the display unit 150 to display that the stacked amount of sheets is large.

In the present embodiment, the remaining amount state of the sheet 12 is displayed on the display unit 150, but the remaining amount state of the sheet 12 may be displayed on an external device (for example, PC).

Next, as recording or the like is performed on the paper 12, the paper 12 decreases, and as shown in FIGS. 7A and 7B, the paper stack amount of the paper feed tray 21 is less than the predetermined amount A2. When the amount is equal to or larger than the predetermined amount A3, the actuator 74 changes from the non-interference state to the interference state, and the actuator 75 continues to be in the non-interference state. At this time, the sensor 76 is in the ON state and outputs a signal indicating the ON state to the control unit 180, and the sensor 77 continues to output a signal indicating the OFF state to the control unit 180. As a result, the control unit 180 determines, based on the signals from the two sensors 76 and 77, that the medium stacking state indicates that the remaining amount of the sheets 12 in the sheet feeding tray 21 is slightly decreasing. Then, the control unit 180 causes the display unit 150 to display that the loading amount of the sheets 12 is medium loading.

Further, as the recording or the like is performed on the paper 12, the paper 12 is reduced, and as shown in FIGS. 8A and 8B, the paper stack amount of the paper feed tray 21 is less than the predetermined amount A3. In the case of the fixed amount A4 or more, the actuator 74 continues to be in the interference state, and the actuator 75 is changed from the non-interference state to the interference state. At this time, the sensor 76 continues to output a signal indicating the ON state to the control unit 180, the sensor 77 is turned on, and outputs a signal indicating the ON state to the control unit 180. As a result, the control unit 180 determines based on the signals from the two sensors 76, 77 that the remaining amount of the paper 12 in the paper feed tray 21 is considerably low, which is a near-empty state. Then, the control unit 180 causes the display unit 150 to display that the stacking amount of the sheets 12 is near empty.

Then, when the paper 12 in the paper feed tray 21 is exhausted, as shown in FIG. 9, the actuator 74 changes from the interference state to the non-interference state, and the actuator 75 continues to be in the interference state. At this time, the sensor 76 is in the OFF state, the control unit 180 outputs a signal indicating the OFF state, and the sensor 77 continues to output the control unit 180 a signal indicating the ON state. As a result, the control unit 180 determines that the empty state indicating that there is no sheet 12 in the sheet feed tray 21 is based on the signals from the two sensors 76 and 77. Then, the control unit 180 causes the display unit 150 to display that the stacking amount of the paper 12 is empty. In this way, the control unit 180 can determine the remaining amount of paper in the paper feed tray 21 based on the signals from the two sensors 76 and 77, and display the remaining amount state on the display unit 150.

As described above, according to the sheet feeding device 20 of this embodiment, the swing of the arm 72 according to the change in the remaining amount of the sheets 12 stacked on the sheet feeding tray 21 causes the swing fulcrums of the actuators 74 and 75. The support shafts 72b1 and 72b2 are moved downward. At this time, the actuators 74 and 75 swing around the support shafts 72b1 and 72b2. Therefore, even if the small-sized actuators 74 and 75 which are relatively short are used, the actuators 74 and 75 can contact the paper 12 in accordance with the change in the remaining amount of the paper 12, and the paper 12 is stacked on the paper feed tray 21. It is possible to widen the range of the amount. That is, the actuator 74 can contact the paper 12 in accordance with the change in the remaining amount of the paper 12 in the range of the load amount from the predetermined amount A2 to the predetermined amount A4. The actuator 75 can follow the change in the remaining amount of the paper 12 and come into contact with the paper 12 in the range of the load amount from the predetermined amount A1 to the predetermined amount A4. Then, in each of the actuators 74 and 75, the remaining amount of the sheet 12 when the swinging posture is switched between the first postures B1 and C1 and the second postures B2 and C2 is determined by the shape of the actuators 74 and 75 and the sensor 76, By adjusting the position of 77 or the like, it is possible to appropriately select from a wide load range. Therefore, it is possible to achieve both the downsizing of the sheet feeding device 20 by downsizing the actuators 74 and 75 and the convenience improvement by expanding the remaining amount detectable range of the sheet 12.

Further, in the present embodiment, the remaining amount of the paper 12 is detected by using the two actuators 74 and 75 and the two sensors 76 and 77, and the maximum number of stacked papers 12 to 0 is detected. In the sensor 76, the ON state and the OFF state are switched twice, and in the sensor 77, the ON state and the OFF state are switched once. Then, the switching timings of the states of the sensors 76 and 77 are different from each other. That is, when one sheet 12 is loaded, only one of the two sensors 76 and 77 is switched. Therefore, the remaining amount of the paper 12 in the paper feed tray 21 can be determined in three steps or four steps.

In particular, in the present embodiment, the sensor 76 switches the state twice and the sensor 77 switches the state once while the stacking amount of the sheets 12 on the sheet tray 21 changes from the predetermined amount A1 to 0 sheets. Then, in the sensor 77, when the stacking amount of the paper 12 is between the two stacking amounts corresponding to the two switching of the state of the sensor 76, the switching of the state is performed once. Therefore, the remaining amount of the sheet 12 can be detected in four stages.

Further, as each actuator 74, 75, a relatively short and small actuator that interferes with one corresponding sensor 76, 77 can be used.

Further, there is a range of the stacking amount of the paper 12 in which the two actuators 74 and 75 can contact the same paper 12. More specifically, the two actuators 74 and 75 contact the same sheet 12 within a range in which the number of sheets is equal to or less than the first predetermined number (150 sheets in this embodiment). Therefore, the positions of the two actuators 74 and 75 in the vertical direction D1 do not significantly differ. If there is no range of the stacking amount of the paper 12 where the two actuators can contact the same paper 12, the positions of these actuators greatly differ in the vertical direction D1. In this embodiment, the positions of the two actuators 74 and 75 are substantially the same in the vertical direction D1. Therefore, it is possible to reduce the size of the sheet feeding device 20 in the up-down direction D1 while realizing multi-stage remaining amount detection in four stages.

The actuator 74 is biased in the arrow F1 direction by a coil spring 74d. Therefore, the swinging operation of the actuator 74 due to the reduction of the remaining amount of the paper 12 is surely performed. Further, the actuator 75 is biased in the arrow F2 direction by its own weight. In this case as well, the swinging operation of the actuator 74 is performed as the remaining amount of the paper 12 decreases.

As a modification, the actuator 75 may be biased in the arrow F2 direction by a biasing member. As another modified example, the actuator 74 may not be biased by the coil spring 74d but may be biased in the arrow F1 direction by its own weight. The biasing member may be composed of an elastic member other than the coil spring. In this case, the force X1 applied to the actuator 74 rotating in the direction of the arrow F1 is X1=N×μ×sin σ (N: vertical load of the actuator 74, μ: contact point 74e of the actuator 74 depending on the type of the paper 12) Coefficient of friction between the paper 12 and the paper 12, σ: contact angle of the actuator 74 with the paper 12, specifically, an angle formed between the virtual line connecting the contact point 74e of the actuator 74 and the support shaft 72b1 and the paper 12. ). On the other hand, the force X2 applied to the actuator 74 rotating in the direction opposite to the direction of the arrow F1 is X2=N×tan σ×sin σ (N: vertical load of the actuator 74, σ: contact angle of the actuator 74 to the paper 12, Is an angle formed between an imaginary line connecting the contact portion 74e of the actuator 74 and the support shaft 72b1 and the paper 12. Since it is necessary to satisfy X2>X1 in order to rotate the actuator 74, it is desirable to determine the position of the support shaft 72b1 so as to satisfy this condition.

As another modification, as shown in FIG. 12, in the sheet feeding unit 270, the contact points 274e and 275e of the actuators 274 and 275 are positioned within the width of the sheet feeding roller 71 in the left-right direction D3 (axial direction). The arm 272 may be included. The same parts as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 12, the actuators 274 and 275 are swingably supported by the support frame 272b via support shafts 272b1 and 272b2. The contact point 274e of the actuator 274 with the sheet 12 is arranged at the rear end. The contact point 275e of the actuator 275 with the sheet 12 is arranged at the substantial center in the front-rear direction D2. These actuators 274 and 275 are configured to swing in mutually opposite directions as the remaining amount of the paper 12 decreases, as in the above-described embodiment. When these contact points 274e, 275e are arranged within the width of the paper feed roller 71 in the left-right direction D3, the rotational moment applied to the paper 12 due to the contact between the contact points 274e, 275e and the paper 12 is reduced. For example, when the contact portion of the actuator with the paper is not located within the width of the paper feed roller 71, the paper 12 fed by the paper feed roller 71 causes a rotation moment due to the contact with the actuator. If this rotation moment is large, the sheet 12 will be skewed when the sheet 12 is fed, and a conveyance failure will occur. However, in this modification, since the contact points 274e and 275e are located within the width of the sheet feeding roller 71, the rotation moment is suppressed. Therefore, skew feeding is less likely to occur when the paper 12 is fed.

As a reference example, consider a feeding device in which the swing fulcrum of the actuator is fixed above the arm 72 (for example, the frame 11a1 of the housing 11a). In this case, the range of the stacking amount of the paper 12 in the paper feed tray 21 where the actuator can contact the paper 12 depends on the length of the actuator, and if the actuator is short, it is relatively narrow. Therefore, to extend this range, the actuator must be lengthened. On the other hand, in the present embodiment, as described above, since the swing fulcrums of the actuators 74 and 75 move downward with the swing of the arm 72, the actuators 74 and 75 themselves swing, which is a comparative example. Even with the relatively short actuators 74 and 75, the range of the stacking amount of the paper 12 in the paper feed tray 21 where the actuators 74 and 75 can contact the paper 12 is widened.

As another reference example, a case where an actuator that swings around the swing fulcrum of the arm 72 with the swing of the arm 72 is provided will be considered. In this case, from the viewpoint of downsizing the arm length, the swing fulcrum of the arm 72 is arranged at a position slightly higher than the uppermost sheet in the state where the maximum number of sheets 12 to be stacked is stored in the sheet feed tray 21. The actuator is arranged at a height position higher than the swing fulcrum of the arm 72. As a result, the swing range of the portion of the actuator that interferes with the sensor is provided above the swing fulcrum. Therefore, a space for securing the swing range of the actuator is required above the swing fulcrum of the arm, and the sheet feeding device itself becomes large. However, the actuator according to the present embodiment is supported by the arm 72 so as to be capable of swinging about the swinging fulcrum provided between the swinging fulcrum of the arm 72 and the tip portion thereof, so that the paper feeding device 20 can be downsized. It becomes possible to do.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. As described above, the present invention is applicable regardless of the number of actuators included in the feeding device. That is, in the present invention, the feeding device may have only one actuator. Further, the feeding device may have three or more actuators. In this case, as many sensors as the number of actuators may be provided.

Further, in the above-described embodiment, the first predetermined amount of the actuator 74 is smaller than the maximum sheet loading amount, but the first predetermined amount of the actuator 74 may be the maximum sheet loading amount. Furthermore, in the above-described embodiment, the second predetermined amount of the actuators 74 and 75 is the amount corresponding to one sheet of paper, but it may be larger than that. Further, the second predetermined amount of the actuator 74 and the actuator 75 may be different from each other.

Further, although the transmission type optical sensor fixed to the arm is used as the sensor in the above-described embodiment, in the present invention, the swinging posture of the actuator is set to the first posture and the second posture. A sensor other than the transmissive optical sensor may be used as long as it can output a distinguishable signal, and the installation location of the sensor can be appropriately selected. For example, the sensors 76 and 77 may be mechanical sensors that switch between the ON state and the OFF state when the interference portions 74a1 and 75b of the actuators 74 and 75 contact each other. Further, the sensor may be a sensor capable of taking three or more states. As the sensor, for example, a variable resistor whose resistance value changes by the swing of the actuators 74 and 75 may be provided on the support shafts 72b1 and 72b2. This makes it possible to detect the remaining amount of paper in more stages. Note that the same effect can be obtained by using an encoder sensor. Furthermore, two or more sensors may be arranged on the arm along the swinging direction of the actuator to enable multi-stage remaining amount detection. Further, the transmissive optical sensor may be arranged on the actuator, and two or more slits arranged along the swinging direction of the actuator may be formed on the arm. Modifications of such a sensor can be applied regardless of the number of actuators in the feeding device.

Further, in one actuator, the swinging posture is switched between the first posture and the second posture twice or more while the loading amount of the medium in the loading unit changes from the first predetermined amount to the second predetermined amount. May be. Such a configuration can be realized, for example, by adopting the above-described configuration capable of detecting the remaining amount of paper in multiple stages, and in the above-described embodiment, immediately after the sensor 76 related to the actuator 74 changes from ON to OFF. This can also be realized by setting the remaining amount of paper in the paper feed tray 21 to an appropriate number of one or more. That is, in this case, the state of the sensor 76 is switched twice while the actuator 74 is in contact with the sheet. In the present embodiment, the actuator 74 is provided with the contact portion 74a2 so that the contact portion 74a2 contacts the frame 11a1 when the sheet stacking amount of the paper feed tray 21 is equal to or smaller than the predetermined amount A1 and equal to or larger than the predetermined amount A2. Therefore, as described above, the state of the sensor 76 can be reliably maintained in the "OFF state" when the amount is equal to or larger than the predetermined amount A2. Even when the configuration in which a part of the actuator 74 does not abut on the frame 11a1 when the paper stacking amount of the paper feed tray 21 is equal to or less than the predetermined amount A1 and equal to or more than the predetermined amount A2, the sensor 76 of the predetermined amount A2 or more is used. It is possible to set the state to the “OFF state”, that is, the state of the sensor 76 can be switched twice while the actuator 74 is in contact with the sheet.

Further, the contact points 74e, 75e, 274e, 275e of the actuators 74, 75, 274, 275 may be provided anywhere on the actuators 74, 75, 274, 275 as long as they can contact the paper 12. .. The sensors 76 and 77 may be fixed to the housing 11a.

INDUSTRIAL APPLICABILITY The present invention can be applied not only to a multifunction machine, but also to a line type/serial type ink jet printer and a sheet feeding device of a laser type or thermal type recording device. Any sheet other than the sheet 12 may be used.

11a1 frame (contact member)
12 sheets (sheet-shaped medium)
20 Paper feeding device (feeding device)
21 Paper feed tray (stacking section)
71 paper feed roller (feed roller)
72 arm 72b1 support shaft (second support point)
72b2 Support shaft (2nd support point)
74,75,274,275 Actuator 74d Coil spring (biasing member)
74e, 75e, 274e, 275e Contact point 76, 77 Sensor 79 Support shaft (first support point)

Claims (12)

A stacking unit capable of stacking a plurality of sheet-shaped media in a stacked state,
A feeding roller for feeding the medium by rotating while contacting the medium loaded on the loading unit;
An arm that is swingable about a first fulcrum and rotatably supports the feeding roller;
It is possible to swing about a second fulcrum provided between the first fulcrum and the tip of the arm farthest from the first fulcrum on the same side as the feeding roller with respect to the first fulcrum. An actuator supported by the arm,
A sensor that outputs a signal for distinguishing the swinging posture of the actuator from the first posture and the second posture different from the first posture;
The actuator contacts the medium loaded on the loading unit and reduces the loading amount of the medium while the loading amount of the medium on the loading unit changes from a first predetermined amount to a second predetermined amount smaller than the first loading amount. Swinging around the second fulcrum as
The actuator is configured such that the swinging posture is at least between the first posture and the second posture while the stacking amount of the medium in the stacking unit changes from the first predetermined amount to the second predetermined amount. It is configured to be switched once ,
A linear distance from the second fulcrum of the arm to the tip of the arm is longer than a linear distance from a position farthest from the first fulcrum of the actuator to the second fulcrum,
The feeding device , wherein a linear distance from the second fulcrum of the arm to the first fulcrum is longer than a linear distance from a position closest to the first fulcrum of the actuator to the second fulcrum . The feeding device according to claim 1, wherein a contact point of the actuator with the medium is located farther from the first fulcrum than the second fulcrum. The feeding device according to claim 1, wherein the second fulcrum is located farther from the first fulcrum than the contact point between the actuator and the medium. The sensor is a sensor that outputs signals that are different from each other in a first state in which the actuator interferes with the actuator and in a second state in which the actuator does not interfere with each other.
One of the first state and the second state when the actuator is in the first posture, and the other of the first state and the second state when the actuator is in the second posture. feeding apparatus according to claim 1 or 2, characterized in that it is configured. While the stacking amount of the medium in the stacking unit changes from the third predetermined amount, which is larger than the first predetermined amount, to the first predetermined amount, the state of the sensor is changed to the first state by making contact with the actuator. Further comprising an abutting member for maintaining one of the one state and the second state,
When the loading amount of the medium in the loading unit becomes less than the first predetermined amount, the actuator separates from the abutting member, and the state of the sensor changes to the other state of the first state and the second state. The feeding device according to claim 4 , wherein the feeding device is switched. Feeding apparatus according to any one of claims 1 to 5, characterized in that said sensor is supported by the arm. Contact points between the medium of the actuator, the feeding device according to any one of claims 1 to 6, characterized in that it is positioned in the feeding axis direction within the width of the roller. When load of the medium in the loading section become 0 Like the one, of claims 1-7, wherein the swinging posture of the actuator, characterized in that the switch between the second posture and the first posture The feeding device according to claim 1. The swing of the orientation of the actuator with to reduce the load of the medium in the loading section, claim 1-8, characterized in that it further comprises a biasing member for biasing the actuator The feeding device according to item 1. The actuator by its own weight, to any one of claims 1 to 9, characterized in that the loading amount of the medium in the loading section is biased in the direction of oscillation of the actuator associated to reduce The feeding device described. A stacking unit capable of stacking a plurality of sheet-shaped media in a stacked state,
A feeding roller for feeding the medium by rotating while contacting the medium loaded on the loading unit;
An arm that is swingable about a first fulcrum and rotatably supports the feeding roller;
It is possible to swing about a second fulcrum provided between the first fulcrum and the tip of the arm farthest from the first fulcrum on the same side as the feeding roller with respect to the first fulcrum. An actuator supported by the arm,
A sensor that outputs a signal for distinguishing a swinging posture of the actuator with respect to the arm from a first posture and a second posture different from the first posture ;
A linear distance from the second fulcrum of the arm to the tip of the arm is longer than a linear distance from a position farthest from the first fulcrum of the actuator to the second fulcrum,
The feeding device , wherein a linear distance from the second fulcrum of the arm to the first fulcrum is longer than a linear distance from a position closest to the first fulcrum of the actuator to the second fulcrum . A stacking unit capable of stacking a plurality of sheet-shaped media in a stacked state,
A feeding roller for feeding the medium by rotating while contacting the medium loaded on the loading unit;
An arm that is swingable about a first fulcrum and rotatably supports the feeding roller;
It is possible to swing about a second fulcrum provided between the first fulcrum and the tip of the arm farthest from the first fulcrum on the same side as the feeding roller with respect to the first fulcrum. An actuator supported by the arm,
The actuator outputs a signal for distinguishing the swinging posture of the actuator from the first posture and the second posture different from the first posture, and outputs the second posture, the first posture, and the second posture. A sensor that outputs a signal capable of distinguishing a third posture that is different from any of the second postures;
An abutment member configured to contact the actuator,
The actuator is maintained in the first posture by being in contact with the medium loaded in the loading unit and also in contact with the contact member when the loading amount of the medium in the loading unit is equal to or more than a first predetermined amount. When the stacking amount of the medium in the stacking unit becomes less than a first predetermined amount, the stacking unit is separated from the contact member and is switched to the second posture,
Further, the actuator is in contact with the medium loaded in the loading unit while the loading amount of the medium in the loading unit decreases from a first predetermined amount to a second predetermined amount that is less than the first predetermined amount. It swings around a second fulcrum and is configured to switch from the second posture to the third posture ,
A linear distance from the second fulcrum of the arm to the tip of the arm is longer than a linear distance from a position farthest from the first fulcrum of the actuator to the second fulcrum,
The feeding device , wherein a linear distance from the second fulcrum of the arm to the first fulcrum is longer than a linear distance from a position closest to the first fulcrum of the actuator to the second fulcrum .

Images