One or more examples relate to a sheet supplying apparatus that feeds one sheet at a time from a loading table, a sheet processing apparatus employing the sheet supplying apparatus, and an image forming apparatus.
Apparatuses using a sheet-type medium, for example, a cut sheet (hereinafter, referred to as paper), such as, printers, scanners, and ticket machines, employ a sheet supplying apparatus that feeds one sheet at a time from a loading table on which a plurality of sheets are placed.
Examples of a sheet supplying apparatus, a sheet processing apparatus employing the sheet supplying apparatus, and an image forming apparatus will now be described with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements, and, in the drawings, the sizes or thicknesses of elements may be exaggerated for clarity of explanation.
A pickup roller that picks up a sheet of paper from a loading table contacts paper when feeding is performed, but is apart from the paper when feeding is not performed. The pickup roller is provided on a holder supported to be pivotable about a shaft. The pickup roller is connected to the shaft and is rotatable by the shaft. A spring clutch, a torque limiter, and the like are mounted on the shaft to rotate the holder due to a load when the shaft rotates, thereby making the pickup roller be in contact with/apart from paper. However, the spring clutch and the torque limiter may increase a driving load and generate noise when being operated. A difference between pressing forces with which the pickup roller presses paper may increase a risk of multi-feeding.
A stopper that switches between a location for aligning fore-ends of papers contained on the loading table and a location allowing paper to be fed and transported may be employed. In this case, driving equipment, such as a solenoid, is employed to drive the stopper, which causes a cost increase.
One or more examples include a sheet supplying apparatus capable of switching locations of a pickup member and an alignment member, and a sheet processing apparatus employing the sheet supplying apparatus.
One or more examples include an image forming apparatus capable of pressing/releasing a pressing roller to/from a fixing roller.
One or more examples include an image forming apparatus capable of pressing/releasing an intermediate transfer roller to/from a photoconductor.
Additional examples will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the disclosed examples.
According to one or more examples, a sheet supplying apparatus may include a loading table on which media of a sheet type are contained, a pickup member configured to pick up the media, an alignment member pivotable to an alignment location for blocking and aligning fore-ends of the media on the loading table, and a transport-allowing location for allowing a medium picked up by the pickup member to be transported, a cam gear including a gear portion partially including a tooth-omitted portion, and a cam portion for switching the alignment member between the alignment location and the transport-allowing location at first and second rotating locations, a main gear, a swing arm pivotable about a same axis as a rotation axis of the main gear, and first and second swing gears supported by the swing arm to interlock with the main gear, selectively interlocking with the gear portion according to a rotating direction of the main gear, and rotating the cam gear to the first and second rotating locations.
According to one or more examples, a sheet processing apparatus may include the above-described sheet supplying apparatus, and a sheet processing unit configured to perform processing on a medium supplied by the sheet supplying apparatus.
According to one or more examples, an image forming apparatus may include a printing unit configured to form a visible toner image on a sheet via electrophotography, a fixing unit configured to fix the visible toner image on the sheet, the fixing unit including a fixing roller and a pressing roller that rotate in mesh with each other, a spring configured to provide an elastic force in a direction allowing the pressing roller to press the fixing roller, a release lever pivotable to a pressing location for providing a pressing force of the spring to the pressing roller, and a releasing location for releasing the pressing force of the spring, a cam gear including a gear portion partially including a tooth-omitted portion, and a cam portion for switching the release lever between the pressing location and the releasing location at first and second rotating locations, a main gear, a swing arm pivotable about a same axis as a rotation axis of the main gear, and first and second swing gears supported by the swing arm to interlock with the main gear, selectively interlocking with the gear portion according to a rotating direction of the main gear, and rotating the cam gear to the first and second rotating locations.
According to one or more examples, an image forming apparatus may include a printing unit configured to form a visible toner image on a plurality of photoconductors via electrophotography, a plurality of intermediate transfer rollers opposite the plurality of photoconductors, an intermediate transfer belt interposed between the plurality of intermediate transfer roller and the plurality of photoconductors, a spring configured to apply an elastic force to the plurality of intermediate transfer rollers such that the plurality of intermediate transfer rollers approach the plurality of photoconductors, a releasing member movable to a pressing location for allowing at least one of the plurality of intermediate transfer rollers to approach a photoconductor corresponding to the at least one intermediate transfer roller and a releasing location for spacing the at least one of the plurality of intermediate transfer rollers apart from the photoconductor corresponding to the at least one intermediate transfer roller, a cam gear including a gear portion partially including a tooth-omitted portion, and a cam portion for switching the releasing member between the pressing location and the releasing location at first and second rotating locations, a main gear, a swing arm pivotable about a same axis as a rotation axis of the main gear, and first and second swing gears supported by the swing arm to interlock with the main gear, selectively interlocking with the gear portion according to a rotating direction of the main gear, and rotating the cam gear to the first and second rotating locations.
The pickup roller 20 is supported by a holder 40 that is pivotable. As shown in
When the pickup roller 20 rotates at the pickup location, the sheet P1 is picked up and fed out of the loading table 10. In some case, the sheet P1 and at least one sheet P2 below the sheet P1 may be guided out together, which is referred to as multi-feeding.
The sheet supplying apparatus 1 may further include a separating unit 30 separating and transporting one sheet, for example, the sheet P1, when multi-feeding occurs. The separating unit 30 may have various structures, such as a friction separation structure and a retard-type separation structure. Because the structure of the separating unit 30 is well known, a separating unit 30 having a retard-type separation structure will now be described in brief.
The separating unit 30 may include a feed roller 31, a retard roller 32, and a torque limiter 33. The feed roller 31 and the retard roller 32 rotate in mesh with each other. The feed roller 31 is connected to, for example, a motor 100, and is rotated in a first direction B1 such that the papers P are transported in a withdrawing direction A1. A driving force in a second direction B2 to transport the papers P in a direction A2 opposite the withdrawing direction A1 is transmitted from the motor 100 to the retard roller 32. The torque limiter 33 limits the driving force in the second direction B2 transmitted to the retard roller 32. The torque limiter 33 may have various well-known structures. For example, the torque limiter 33 may be implemented by a spring clutch structure. The torque limiter 33 may be provided between, for example, a rotation shaft 32-1 and the retard roller 32 or between a gear 34 transmitting the driving force of the motor 100 in the second direction B2 to the rotation shaft 32-1 and the rotation shaft 32-1.
The torque limiter 33 limits the driving force in the second direction B2 transmitted to the retard roller 32, according to the size of a load torque applied to the retard roller 32. When the load torque applied to the retard roller 32 is less than a threshold torque provided by the torque limiter 33, the driving force in the second direction B2 is transmitted to the retard roller 32, and thus the retard roller 32 rotates in the second direction B2. When the load torque applied to the retard roller 32 exceeds the threshold torque provided by the torque limiter 33, the driving force in the second direction B2 transmitted to the retard roller 32 is blocked by the torque limiter 33. In this case, the retard roller 32 is rotated in a third direction B3 by the feed roller 31.
A separating operation according to such a structure will now be described in brief.
When no paper P or one sheet of paper P is guided between the feed roller 31 and the retard roller 32, the load torque applied to the retard roller 32 is greater than the threshold torque of the torque limiter 33, and thus the torque limiter 33 blocks the driving force toward the retard roller 32. Accordingly, the retard roller 32 rotates in the third direction B3 for transporting the papers P in the withdrawing direction A1 in corporation with the feed roller 31.
When at least two sheets of paper P, for example, the sheet P1 and the sheet P2, are guided between the feed roller 31 and the retard roller 32, the sheet P1 and the sheet P2 contact the feed roller 31 and the retard roller 32, respectively. At this time, friction between the sheet P1 and the sheet P2 is less than friction between the sheet P2 and the retard roller 32. Thus, a slip occurs between the sheet P1 and the sheet P2, and the load torque applied to the retard roller 32 is less than the threshold torque provided by the torque limiter 33. The retard roller 32 rotates in the second direction B2, and the sheet P2 is transported in the direction A2 opposite the withdrawing direction A1 by the retard roller 32. Accordingly, the sheet P1 passes between the feed roller 31 and the retard roller 32 and is transported in the withdrawing direction A1.
The sheet supplying apparatus 1 may further include an alignment member 60. The alignment member 60 is positioned at an alignment location, as shown in
The alignment member 60 may be coupled to a pivoting shaft 120.
For example, the holder 40 is provided to be pivotable about a rotation shaft 31-1 of the feed roller 31. The pickup roller 20 rotates in connection with the feed roller 31. According to an example, the pickup roller 20 is connected to the feed roller 31 via a timing belt 80, but a gear (not shown) may be used instead of the timing belt 80. In this case, an odd number of gears are employed so that the pickup roller 20 and the feed roller 31 rotate in the same direction.
A first elastic member 50 applies, to the holder 40, an elastic force in a direction allowing the holder 40 to be pivoted to the pickup location. For example, the first elastic member 50 may be one of various types of members including a compression coil spring, a tension coil spring, a torsion spring, and the like.
When the alignment member 60 pivots from the transport-allowing location to the alignment location, the alignment member 60 may push the holder 40 in a direction opposite a direction of the elastic force of the first elastic member 50 and pivots the holder 40 to the separating location. At the alignment location, the alignment member 60 supports the holder 40 and maintains the holder 40 at the separating location. When the alignment member 60 pivots from the alignment location to the transport-allowing location, the holder 40 pivots from the separating location to the pickup location due to the elastic force of the first elastic member 50.
According to this structure, without providing a torque limiter or a spring clutch on the feed roller 31 and the pickup roller 20, the pickup roller 20 may be switched between the pickup location and the separating location. Accordingly, a location of the pickup roller 20 may be switched without an increase in a driving load or generation of noise. Because a pressing force of pressing the pickup roller 20 down on the papers P is determined by the first elastic member 50, a stable pressing force may be applied to the pickup roller 20, and thus the risk of multi-feeding due to a difference between pressing forces applied may be reduced.
An example of a structure for switching the alignment member 60 between the alignment location and the transport-allowing location will now be described. According to an example, the alignment member 60 is switched between the alignment location and the transport-allowing location by using a swinging operation of a gear without using a driver, such as a solenoid.
Referring to
A cam gear 140 switches the alignment member 60 between the alignment location and the transport-allowing location according to a rotation phase of the cam gear 140.
The sheet supplying apparatus 1 may further include a second elastic member 150 which provides an elastic force in a direction allowing the alignment member 60 to be switched to the transport-allowing location. For example, the second elastic member 150 applies, to the pivoting shaft 120, the elastic force in a direction allowing the alignment member 60 to be switched to the transport-allowing location. The second elastic member 150 may be a torsion spring, as shown in
The cam gear 140 is rotated by the motor 100. A main gear 160 is connected to the motor 100. A swing arm 170 is pivotable about the same axis as a rotation axis of the main gear 160. For example, the swing arm 170 may be pivotable about the rotation axis of the main gear 160. First and second swing gears 181 and 182 engage with the main gear 160.
According to such a structure, the swing arm 170 pivots in the same direction as a rotation direction of the main gear 160. Thus, according to the rotation direction of the main gear 160, the first and second swing gears 181 and 182 are selectively connected to the gear portion 141 of the cam gear 140. In order to prevent changing of a rotation direction of the cam gear 140 even when the rotation direction of the main gear 160 is changed, an idle gear 190 is interposed between one of the first and second swing gears 181 and 182 and the gear portion 141. According to an example, the idle gear 190 is interposed between the second swing gear 182 and the gear portion 141. The number of idle gears 190 is an odd number. According to an example, the single idle gear 190 engages with the gear portion 141.
Referring to
In the state shown in
When the motor 100 continuously rotates in the forward direction, the cam gear 140 rotates in a direction D1, as shown in
When the second elastic member 150 is not included, the alignment member 60 may be pushed by the holder 40 pivoted to the pickup location due to the elastic force of the first elastic member 50 and thus pivoted to the transport-allowing location, and consequently the alignment member 60 may contact the stopper 70.
When the contact between the cam portion 143 and the lever 130 is terminated, namely, when the cam gear 140 reaches the second rotating location, the first swing gear 181 is positioned on the tooth-omitted portion 142. The idle gear 190 deviates from the tooth-omitted portion 142 and is connected to the gear portion 141, but the second swing gear 182 is spaced apart from the idle gear 190. Thus, in this state, even when the motor 100 rotates in the forward direction, the cam gear 140 does not rotate, and a sheet P is guided out of the loading table 10 by the pickup roller 20.
When feeding of the sheet P is completed, an operation of switching the alignment member 60 to the alignment location and the holder 40 to the separating location is performed.
The motor 100 rotates in a backward direction. As shown in
When the motor 100 continuously rotates in the backward direction, the cam gear 140 rotates in the direction D1, as shown in
As shown in
When an abnormal feeding-terminated situation occurs, such as, when a jam occurs during feeding or when the sheet supplying apparatus 1 is powered off, an operation of addressing the abnormal feeding-terminated situation and then initializing the location of the cam gear 140 may be needed. In this case, the motor 100 rotates in the forward direction for a certain period of time. Then, the cam gear 140 is positioned at the second rotating location, as shown in
The shape of the cam profile 144 of the cam portion 143 and a connection structure between the cam portion 143 and the lever 130 are not limited to the aforementioned examples. The shape of the cam profile 144 of the cam portion 143 and the connection structure between the cam portion 143 and the lever 130 may be implemented as various examples capable of switching the alignment member 60 between the alignment location and the transport-allowing location.
As such, without employing an additional driving source, such as a solenoid, the alignment member 60 may be switched between the alignment location and the transport-allowing location and the holder 40 may be switched between the pickup location and the separating location, due to the forward rotation and the backward rotation of the motor 100 for driving the sheet supplying apparatus 1. Thus, costs for manufacturing the sheet supplying apparatus 1 may be reduced.
The above-described sheet supplying apparatus 1 is applicable to various apparatuses (sheet processing apparatuses).
The read unit 600b may include a read member 650 for reading an image from the document D. The read member 650 radiates light to the document D, and receives light reflected by the document D to thereby read the image from the document D. For example, a contact type image sensor (CIS), a charge-coupled device (CCD), or the like may be employed as the read member 650.
Types of the scanner 600 include a flatbed type in which the document D is located in a fixed location and a read member, such as a CIS or a CCD, reads an image from the document D while moving, a document feed type in which the read member is located in a fixed location and the document D is transported, and a combination of the two types. The scanner 600 according to an example is a scanner of a combination of the flatbed type and the document feed type.
The read unit 600b further may include a platen glass 660 on which the document D is placed so that an image is read from the document D using a flatbed method. The read unit 600b further may include a read window 670 for reading an image from the document D therethrough by using a document feed method. The read window 670 may be, for example, a transparent member. For example, a top surface of the read window 670 may be at a same level as a top surface of the platen glass 660.
When the document feed method is applied, the read member 650 is located below the read window 670. When the flatbed method is applied, the read member 650 may be moved from below the platen glass 660 in a sub-scanning direction S, namely, a lengthwise direction of the document D, by a transportation unit (not shown). Moreover, when the flatbed method is applied, the platen glass 660 needs to be exposed to the outside such that the document D is placed thereon. To this end, the document transport unit 600a may expose the platen glass 660 by being pivoted with respect to the read unit 600b.
The document transport unit 600a transports the document D such that the read member 650 may read an image from the document D, and discharges the document D from which an image has been read. To this end, the document transport unit 600a may include a document transport path 610, and the read member 650 reads an image from the document D transported along the document transport path 610. For example, the document transport path 610 may include a supply path 611, a read path 612, and a discharge path 613. The read member 650 is disposed on the read path 612, and, while the document D is passing the read path 612, the image recorded on the document D is read out by the read member 650. The supply path 611 is used to supply the document D to the read path 612, and the document D placed on the loading table 10 is supplied to the read path 612 via the supply path 611. The discharge path 613 is used to discharge the document D that has passed the read path 612. Accordingly, the document D placed on the loading table 10 is transported along the supply path 611, the read path 612, and the discharge path 613 and is discharged to a discharge tray 630.
Transporting rollers 621 and 622 for transporting the document D led out of the loading table 10 by the sheet supplying apparatus 1 may be arranged on the document transport path 610. Each of the transporting rollers 621 and 622 has a structure in which a driving roller and a driven roller rotate in mesh with each other.
Transporting rollers 623 and 626 transporting the document D may be arranged on the read path 612. For example, the transporting rollers 623 and 626 transporting the document D may be arranged on both sides of the read member 650, respectively. Each of the transporting rollers 623 and 626 has a structure in which a driving roller and a driven roller rotate in mesh with each other. A read guiding member 624 opposite to the read member 650 is disposed on the read path 612. The read guiding member 624 presses the read window 670 by the own weight of the read guiding member 624 or by an elastic member 625, and the document D is transported between the read window 670 and the read guiding member 624. Although not shown in
A discharge roller 627 discharging the document D on which reading has been completed is disposed on the discharge path 613. The discharge roller 627 has a structure in which a driving roller and a driven roller rotate in mesh with each other.
According to this structure, the document D supplied by the sheet supplying apparatus 1 may be transported along the supply path 611, the read path 612, and the discharge path 613, and the read member 650 may read an image from the document D.
The shape of the scanner 600 is not limited to the example of
The printing unit 700a according to an example may print an image on the sheet P according to any of various methods, such as electrophotography, inkjet printing, thermal transfer printing, and thermal sublimation. The image forming apparatus 700 according to an example prints a color image to the sheet P via electrophotography. Referring to
For color printing, the plurality of developing units 710 may include four developing units 710 for developing images with cyan (C) color, magenta (M) color, yellow (Y) color, and black (K) color, respectively. Toners with cyan (C) color, magenta (M) color, yellow (Y) color, and black (K) color may be contained in the four developing units 710, respectively. The printing unit 700a further may include developing units 710 for containing and developing toners of other various colors such as a light magenta color, a white color, or the like.
Each developing unit 710 may include a photoconductive drum 7a. The photoconductive drum 7a, as a photoconductor on which an electrostatic latent image is formed, may include a conductive metal pipe and a photosensitive layer formed at an outer circumference of the conductive metal pipe. A charging roller 7c is an example of a charger that charges a surface of the photosensitive drum 7a to have a uniform surface potential. A cleaning blade 7d is an example of a cleaning member that removes residual toners and foreign substances attached to the surface of the photosensitive drum 7a after a transfer process to be described below.
The developing unit 710 supplies a toner contained therein to an electrostatic latent image formed on the photoconductive drum 7a, thereby developing the electrostatic latent image to a visible toner image. A developing method may include a one-component developing method using a toner and a two-component developing method using a toner and a carrier. In an example, the developing unit 710 employs the one-component developing method. A developing roller 7b supplies a toner to the photoconductive drum 7a. A developing bias voltage may be applied to the developing roller 7b to supply the toner to the photosensitive drum 7a.
The one-component developing method may be classified into a contact developing method in which the developing roller 7b and the photoconductive drum 7a rotate in contact with each other, or a non-contact developing method in which the developing roller 7b and the photoconductive drum 7a are spaced apart from each other by several tens to several hundreds of micrometers and rotate. A supply roller 7e supplies the toner in the developing unit 710 to a surface of the developing roller 7b. A supply bias voltage for supplying the toner in the developing unit 710 to a surface of the developing roller 7b may be applied to the supply roller 7e.
The exposure unit 720 radiates light modulated in correspondence with image information onto the photoconductive drum 7a and forms the electrostatic latent image on the photoconductive drum 7a. Examples of the exposure unit 720 may include a laser scanning unit (LSU) using a laser diode as a light source and a light emitting diode (LED) exposure unit using an LED as a light source.
The transfer unit may include an intermediate transfer belt 731, an intermediate transfer roller 732, and a transfer roller 733. The intermediate transfer belt 731 temporarily receives a toner image developed on the photoconductive drum 7a of each of the four developing units 710. The intermediate transfer belt 731 is circulated while being supported by supporting rollers 734, 735, and 736. Four intermediate transfer rollers 732 are positioned to face the photoconductive drums 7a of the four developing units 710 with the intermediate transfer belt 731 therebetween. A first transfer bias voltage is applied to the four intermediate transfer rollers 732 so as to firstly transfer toner images, which are developed on the photosensitive drums 7a, to the intermediate transfer belt 731. The transfer roller 733 is positioned to face the intermediate transfer belt 731. A second transfer bias voltage is applied to the transfer roller 733 so as to transfer, to the sheet P, the toner images that are firstly-transferred to the intermediate transfer belt 731.
When a print command is transmitted from a host (not shown) or the like, a controller (not shown) charges, by using the charging roller 7c, the surface of the photoconductive drum 7a to have a uniform surface potential. The exposure unit 720 forms electrostatic latent images on the photoconductive drums 7a by scanning four light-beams to the photoconductive drums 7a of the four developing unit 710, the four light-beams being modulated according to image information corresponding to cyan, magenta, yellow, and black colors, respectively. The developing rollers 7b of the four developing units 710 supply C, M, Y, and K toners to the photoconductive drums 7a, respectively, thereby developing the electrostatic latent images into visible toner images. The developed toner images are firstly transferred to the intermediate transfer belt 731. The sheet P from the sheet supplying apparatus 1 is transported to a transfer nip formed by the transfer roller 733 and the intermediate transfer belt 731. The toner images that are firstly-transferred to the intermediate transfer belt 731 are secondly transferred to the sheet P due to the second transfer bias voltage applied to the transfer roller 733. When the sheet P passes through the fixing unit 740, the toner images are fixed on the sheet P due to heat and pressure. The sheet P on which fixing has been completed is externally discharged by a discharging roller 750.
The scanner 600 and the image forming apparatus 700 may be used as independent apparatuses or as a combination of a scanner and an image forming apparatus.
Referring to
The swing arm 170, the first and second swing gears 181 and 182, and the cam gear 140 described above may change a mode of an object via forward and backward rotations of a motor. This structure is applicable to various fields. For example, referring back to
Referring to
When the pressing force needs to be released, the main gear 160 rotates in a backward direction. Then, as shown in
When the main gear 160 continuously rotates in the backward direction, the cam gear 140a rotates as shown in
To perform printing again, an operation of switching the release lever 744 to the pressing location is performed.
When the main gear 160 rotates in the forward direction, the second swing gear 182 is connected to the idle gear 190, as shown in
The main gear 160 may be rotated by a motor (not shown) for driving the pressing roller 742 and the fixing roller 741. The motor (not shown) may drive the other components of the image forming apparatus 700. According to the above-described structure, the pressing force may be released/formed by using the motor that drives the fixing unit 740, without employing a special driving source.
Referring back to
By pivoting the support brackets 761, the intermediate transfer rollers 732Y, 732M, and 732C may be switched between pressing locations and releasing locations. A releasing member 770 is slidably supported by each of the frames 760-1 and 760-2. For example, the releasing members 770 may be slidable in traveling directions F1 and F2 of the intermediate transfer belt 731.
A rotation shaft 780 is rotatably supported by the frames 760-1 and 760-2. A cam gear 140b for sliding the releasing member 770 back and forth is coupled to the rotation shaft 780. The cam gear 140b may include a gear portion 141b and a cam portion 143b. A tooth-omitted portion 142b is partially provided on the gear portion 141b. When the cam portion 143b contacts the first contact portion 771, the releasing member 770 slides in the direction F1, in which the inclined portions 773 interfere with the interfering portion 761-1. Then, the support brackets 761 are pivoted in a direction opposite a direction of the elastic forces of the springs 763, and thus the intermediate transfer rollers 732Y, 732M, and 732C are moved to the releasing locations. When the cam portion 143b contacts the second contact portion 772, the releasing member 770 slides in the direction F2, in which the inclined portions 773 are spaced apart from the interfering portion 761-1. Then, due to the elastic forces of the springs 763, the support brackets 761 are pivoted in a direction for positioning the intermediate transfer rollers 732Y, 732M, and 732C at the pressing locations.
The swing arm 170, the first and second swing gears 181 and 182, and the cam gear 140 described above are employed to rotate the cam gear 140b, thereby reducing the costs for image forming apparatuses.
Referring to
When a single-color image, namely, a K color image, desires to be printed, the main gear 160 is rotated in a backward direction. Then, as shown in
When the main gear 160 continuously rotates in the backward direction, the cam gear 140b is rotated, and thus the cam portion 143b contacts the first contact portion 771, as shown in
To print a color image again, an operation of switching the intermediate transfer rollers 732Y, 732M, and 732C to the pressing locations is performed.
When the main gear 160 rotates in the forward direction, the second swing gear 182 is connected to the idle gear 190, as shown in
The main gear 160 may be rotated by a motor (not shown) for driving the intermediate transfer belt 731. The motor (not shown) may drive the other components of the image forming apparatus 700. According to the above-described structure, the intermediate transfer rollers 732Y, 732M, and 732C may be switched between pressing locations and releasing locations without employing a special driving source.
While one or more inventive concepts have been particularly shown and described with reference to examples thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.
Number | Date | Country | Kind |
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10-2016-0085072 | Jul 2016 | KR | national |
This application is a continuation application on U.S. patent application Ser. No. 15/641,711, filed on Jul. 5, 2017, which claims the priority benefit of Korean Patent Application No. 10-2016-0085072, filed on Jul. 5, 2016, in the Korean Intellectual Property Office, the disclosures of each of which are incorporated herein in their entirety by reference.
Number | Date | Country | |
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Parent | 15641711 | Jul 2017 | US |
Child | 16570627 | US |