Patent Publication Number: US-2022214640-A1

Title: Structure for cleaning sensor

Description:
BACKGROUND 
     An image forming apparatus is an apparatus for generating, printing, receiving, or transmitting image data. Examples of the image forming apparatus include a printer, a scanner, a copy machine, a fax machine, and a multifunction printer integrating these functions. 
     The image forming apparatus is equipped with a plurality of sensors for sensing a size, a position, a material, etc. of a printing paper. During the printing process, dust generated from printing paper or the like may contaminate the sensor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view illustrating an image forming apparatus according to an example. 
         FIG. 2  is a perspective view illustrating a detection apparatus provided with a sensor cleaning device according to an example. 
         FIG. 3  is a block diagram of an image forming apparatus according to an example. 
         FIG. 4  is a side view illustrating a detection apparatus provided with a sensor cleaning device according to an example. 
         FIG. 5  is a partial perspective view illustrating a detection apparatus provided with a sensor cleaning device according to an example. 
         FIG. 6  is a partial enlarged perspective view illustrating a sensor cleaning device according to an example. 
         FIG. 7  and  FIG. 8  are partial exploded perspective views illustrating a sensor cleaning device according to an example. 
         FIG. 9A  and  FIG. 9B  are cross-sectional view views illustrating operations of a sensor cleaning device according to an example. 
         FIG. 10A  and  FIG. 10B  are drawings illustrating a driver applicable to of a sensor cleaning device according to an example. 
     
    
    
     DETAILED DESCRIPTION 
     As those skilled in the art will realize, the following described examples may be modified in various different ways, all without departing from the spirit or scope of the present disclosure. In order to clarify the present disclosure, parts that are not relevant to the description will be omitted, and the same elements or equivalents are referred to by the same reference numerals throughout the specification. Each of the size and thickness of each element is arbitrarily shown in the drawings and the present disclosure is not necessarily limited thereto. In the drawings, the thickness of layers, films, panels, regions, etc., may be exaggerated for clarity. 
       FIG. 1  is a cross-sectional view illustrating an image forming apparatus according to an example. 
     As shown in  FIG. 1 , an image forming apparatus  1  may include a main body  10 , first and second printing medium supply devices  20  and  90  for storage and for supplying of printing medium S, a developing device  30  to form an image on each printing medium S supplied via the first and second printing medium supply devices  20  and  90 , a toner device  40  to feed toner to the developing device  30 , a light scanning device  50  to form an electrostatic latent image on a photoconductor  32 , a fixing device  80  to fix a toner image transferred onto the printing medium S to the printing medium S, and a printing medium discharge device  70  to discharge the printing medium S on which the image has been completely formed to the outside of the main body  10 . 
     The first printing medium supply device  20  may store and supply the printing medium S, and may be located below the main body  10  to supply the printing medium S to the developing device  30 . 
     The printing medium supply device  20  may include a printing medium cassette  21  to be withdrawn from the main body  10  to store the printing medium S, and a delivery member  25  to pick up the printing medium S stored in the printing medium cassette  21  one by one and deliver the same to the developing device  30 . 
     To guide the loaded printing medium S to the delivery member  25 , a knock-up plate  23  may be installed in the printing medium cassette  21  such that one end of the knock-up plate  23  is rotatably coupled to the printing medium cassette  21  and the other end of the knock-up plate  23  is supported by a pressure spring  22 . 
     The delivery member  25  may include a pickup roller  27  to pick up the printing medium S loaded on the knock-up plate  23  one by one, and a feed roller  28  to deliver each printing medium S picked up by the pickup roller  27  to the developing device  30 . 
     The developing device  30  may include a housing  31  defining an external appearance of the developing device  30 , the photoconductor  32  rotatably installed in the housing  31  such that an electrostatic latent image is formed thereon, agitator screws  33   a,    33   b  to agitate toner fed into the toner device  40 , a developing roller  34  to feed the toner agitated by the agitator screws  33   a,    33   b  to the photoconductor  32 , and a charge member  35  to charge the photoconductor  32 . 
     The toner fed from the toner device  40  may be introduced into the housing  31  and is agitated and delivered to one side of the housing  31  by the agitator screws  33   a,    33   b.  The delivered toner may be fed to the photoconductor  32  by the developing roller  34  to form a visible toner image. 
     To transfer the visible toner image formed on the photoconductor  32  to the printing medium S, the photoconductor  32  may come into contact with the transfer roller  14  to define a transfer nip N 1  with a transfer roller  14 . The transfer roller  14  may be rotatably placed within the main body  10 . 
     The toner device  40  may be coupled to the developing device  30  and receive and store toner used to form an image on the printing medium S. The toner device  40  may feed toner to the developing device  30  during an image forming operation. 
     The light scanning device  50  may emit light including image information to the photoconductor  32  to form an electrostatic latent image on the photoconductor  32 . 
     The fixing device  80  may fix the toner image formed on the printing medium S to the printing medium S by applying heat and pressure to the printing medium S. 
     The printing medium discharge device  70  may include a first discharge roller  71  and a second discharge roller  72  which are sequentially arranged to discharge the printing medium S having passed through the fixing device  80  to the outside of the main body  10 . 
     A guide rib  16  may be disposed between the transfer nip N 1  and the fixing device  80  and may guide the printing medium S to pass through the transfer nip N 1  to the fixing device  80 . The guide rib  16  may define a portion of a transferring path P of the printing medium S between the transfer nip N 1  and the fixing device  80 . 
     The second printing medium supply device  90  may store and feed the printing medium S separately from the first printing medium supply device  20  and may be provided on a side of the main body  10  to supply the printing medium S toward the developing device  30 . 
     A detection apparatus  100  may be interposed between the first and second printing medium supply apparatuses  20  and  90  and the detection apparatus  100  may include a driving roller  120  and a driven roller  122  to transfer the printing medium S. 
     As an example, the detection apparatus  100  may include a sensor to detect a size, a position or a material, etc. of the printing medium S. The detection apparatus  100  may also include a sensor cleaning device to remove dirt, such as dust, from the sensor. 
       FIG. 2  is a perspective view illustrating a detection apparatus provided with a sensor cleaning device according to an example and  FIG. 3  is a block diagram of an image forming apparatus according to an example. 
       FIG. 4  is a side view illustrating a detection apparatus provided with a sensor cleaning device according to an example and  FIG. 5  is a partial perspective view illustrating a detection apparatus provided with a sensor cleaning device according to an example. 
       FIG. 6  is a partial enlarged perspective view illustrating a sensor cleaning device according to an example and  FIG. 7  and  FIG. 8  are partial exploded perspective views illustrating a sensor cleaning device according to an example. 
       FIG. 9A  and  FIG. 9B  are cross-sectional view views illustrating operations of a sensor cleaning device according to an example. 
     In describing the sensor cleaning device according to an example of the present disclosure, a sensor cleaning device mounted on a detection apparatus is described as an example for convenience of understanding, but the sensor cleaning device is not limited thereto. The sensor cleaning device can be applied to various configurations. 
     The detection apparatus according to an example of the present disclosure may include, for example, a pick up unit to move a sheet of the printing medium S from the printing medium cassette  21 , a speed adjusting unit to adjust a moving speed of the printing medium S, a registration unit for detecting paper type and/or material and the like. 
     In describing the detection apparatus according to an example of the present disclosure, for the convenience of understanding, the detection apparatus  100  will be described as an example of a registration unit. 
     The sensor cleaning device according to an example of the present disclosure is provided to clean a sensor that senses the printing medium S on the transferring path P. 
     Here, the transferring path P may refer to a path through which the printing medium S moves, as described above. 
     The sensor cleaning device according to an example of the present disclosure may include a cleaning lever  150  connected with a cleaner  152  at one end and a driver  170  to drive the cleaning lever  150 . 
     The cleaner  152  may move from a first position to a second position and back to the first position, the first position being away from the transferring path P and the second position being in contact with the sensor according to an operation of the driver  170 . 
     The sensor may include a first sensor  130  disposed on one side of the transferring path P and a second sensor  132  disposed on the other side of the transferring path P to face the first sensor  130 . 
     One of the first sensor  130  and the second sensor  132  may be a light emitting portion to irradiate light toward the printing medium S, and the other may be a light receiving portion. 
     The cleaner  152  may clean the light emitting portion and/or the light receiving portion according to the operation of the driver  170 . 
     The first position, as shown in  FIG. 9A , may be defined as a position at which the cleaner  152  and the cleaning lever  150  deviate from the transferring path P so as not to interfere with the movement of the printing medium S. 
     The second position, as shown in  FIG. 9B , may be defined as a position on the transferring path P protruded such that the cleaner  152  cleans the light emitting portion and/or the light receiving portion. 
     The sensor cleaning device according to an example of the present disclosure may further include a guide rail  190  disposed adjacent to the transferring path P and a guide projection part  154  formed to the cleaning lever  150  in contact with the guide rail  190  to guide movement of the cleaning lever  150 . 
     The guide rail  190  may include a first rail  192  inclined to the transferring path P to protrude the cleaning lever  150  and a second rail  194  parallel to the transferring path P for the cleaner  152  to contact the sensor  130  and/or  132  and clean the sensor  130  and/or  132 . In addition, the guide rail  190  may further include a stopper  195  for limiting movement of the cleaning lever  150 . 
     The sensor cleaning device may further include a lever spring  158  providing the cleaning lever  150  with restoring force in the first position direction. 
     The sensor cleaning device may further include a guide block  185  formed adjacent to the guide rail  190  to guide movement of the cleaner  152 . 
     The cleaner  152  may be made of a cloth material, for example. The material may be made of a flexible material such as felt, woven fabric, non-woven fabric, knit, and band. The material may be a suitable material for removing contaminants of the sensor  130  and/or  132 . 
     The first sensor  130  may be mounted to a first housing  102 , and the second sensor  132  facing the first sensor  130  may be coupled to a second housing  104  and the guide rail  190  may be formed inside the first housing  102 . 
     The driving roller  120 , the driven roller  122 , the first housing  102  and the second housing  104  may be coupled to the main body  10 . 
     The image forming apparatus according to an example of the present disclosure may further include a processer  110  that controls operations of the first sensor  130  and the second sensor  132  and detects an operation state. 
     The processer  110  may control the operation of the driver  170  such that the cleaner  152  is positioned at the first position when the printing medium S on the transferring path P passes, and may control the operation of the driver  170  such that the cleaner  152  cleans the sensor  130  and/or  132  at the second position when there is no printing medium S on the transferring path P. 
     For example, the processer  110  may determine whether the printing medium S exists on the transferring path P and control the operation of the driver  170  according to the output signal of the sensor  130  and/or  132 . 
     The image forming apparatus according to an example of the present disclosure may further include a memory  200  communicating with the processer  110 . 
     The processer  110  may determine whether a number of operations stored in the memory  200  exceed a predetermined number of operations, or whether a sensitivity of the light emitting portion or the light receiving portion is less than a predetermined sensitivity. 
     One of the first sensor  130  and the second sensor  132  may be the light emitting portion, and the other may be the light receiving portion. 
     The light emitting portion is a light-emitting device that emits light, and may be, for example, a light emitting diode (LED), but is not limited thereto. The light receiving portion may be disposed almost in line with the light path of the light emitted from the light emitting portion and may include a light receiving element that detects an amount of light passing through the printing medium S from the light emitting portion. 
     The light emitting portion may also include a light receiving element that detects the amount of light reflected from the printing medium S. 
     The first sensor  130  and the second sensor  132  may be, for example, a reflective type medium sensor, but is not limited. 
     The light emitting portion and the light receiving portion may detect the type and/or material of the printing medium S, and the printing medium S may be a printing substance of various forms such as a paper, a paperboard, a overhead project film OHP and the like. 
     The processer  110  may operate the driver  170  when the number of operations stored in the memory  200  exceeds a predetermined number of operations or when the sensitivity of one of the light emitting portion and the light receiving portion is less than the predetermined sensitivity. 
       FIG. 10A  and  FIG. 10B  are drawings illustrating a driver applicable to of a sensor cleaning device according to an example. 
     Referring to  FIG. 2 ,  FIG. 4  and  FIG. 10 , the driver  170  may include a guide plate  176  coupled to a driving lever  177  to drive the cleaning lever  150 , of which a driving groove  178  into which a driving shaft  175  is inserted to be movable is formed to the guide plate  176 , and the guide plate  176  to be relatively movable to a driving guider  173 . 
     The driving guider  173  may include guide shafts  173   a  and  173   b  provided along the first position and the second position directions, and the guide plate  176  may be formed with a guide groove  179  into which the guide shafts  173   a  and  173   b  are inserted. 
     The driving guider  173  is provided on the driving plate  172 , and a driving motor  180  is coupled to the driving plate  172 . A main gear  174  engaged with the driving motor  180  is rotatably coupled to the driving plate  172  via a rotation axis  171 , and the driving shaft  175  is coupled to the main gear  174 . 
     The driving guider  173  and the driving groove  178  may be formed in a perpendicular direction. 
     Hereinafter, referring to  FIG. 1  to  FIG. 8 , an operation of an image forming apparatus equipped with the sensor cleaning device according to an example of the present disclosure will be described. 
     When the first driving roller  120  and the driven roller  122  rotate, the printing medium S is supplied in the arrow direction shown in  FIG. 4 . 
     Referring to  FIG. 2 ,  FIG. 4  and  FIG. 9 , the first sensor  130  and the second sensor  132  are disposed facing the transfer path P, and detect the printing medium S passing through the transferring path P. For example, the first sensor  130  and the second sensor  132  may be a light emitting portion and a light receiving portion for detecting the size, position or material of the printing medium S. 
     If the copying or printing operation is continued, the first sensor  130  and the second sensor  132  may be contaminated by debris or dust of the printing medium S. For example, the sensing surfaces of the first sensor  130  and the second sensor  132  are contaminated, and thus a malfunction of the first sensor  130  and the second sensor  132  may occur. 
     The processer  110  determines whether the number of operations such as copying or printing stored in the memory  200  exceeds the predetermined number of operations. When the number of operations stored in the memory  200  exceeds the predetermined number of operations, the processer  110  may operate the driver  170 . For example, if the number of operations stored in the memory  200  exceeds 10,000, it is determined that the sensor needs to be cleaned, and the processer  110  may operate the driver  170 . The predetermined number of operations is not limited to this example. If the processer  110  runs the driver  170 , the memory  200  may be initialized and applied to a later cleaning operation. 
     In addition, the processer  110  may determine whether or not the sensitivity of the first sensor  130  and the second sensor  132  is less than the predetermined sensitivity. The processer  110  may operate the driver  170  when the sensitivity of the first sensor  130  and the second sensor  132  is below the predetermined sensitivity. For example, if 10% sensitivity is deteriorated compared to the initial sensor sensitivity or the initial design, the sensor needs to be cleaned and the processer  110  may operate the driver  170 . Here, the sensitivity refers to the degree to which the signal output from the first sensor  130  or the second sensor  132  is detected by the second sensor  132  or the first sensor  130 , and in case of deteriorated sensitivity, the detection unit of the first sensor  130  and/or the second sensor  132  may determine that contamination has occurred in the first sensor  130  and/or the second sensor  132 . The predetermined sensitivity is not limited to one example, and may be preset in order to prevent a malfunction of the sensor. 
     Here, the processer  110  determines whether the copying or printing operation is not performed. The copying or printing operation is not performed, when the printing medium S does not pass on the transferring path P. When the printing medium S does not pass on the transferring path, then the driver  170  may be operated. 
     Referring to  FIG. 10 , when the processer  110  operates the driver  170 , the driving motor  180  rotates to rotate the main gear  174  about the rotation axis  171 . 
     Then, the driving shaft  175  coupled to the main gear  174  also rotates about the rotation axis  171 . 
     Since the driving groove  178  into which the driving shaft  175  is inserted is formed in a direction perpendicular to the guide groove  179  and the driving shaft  175  moves relative within the driving groove  178 , the guide plate  176  moves along the driving guider  173 . That is, the guide plate  176  is moved along the driving guider  173  in the arrow direction in  FIG. 10B . Here, the driving guider  173  may include two guide shafts  173   a  and  173   b  as shown in the drawing, but is not limited. 
     When the guide plate  176  moves, the driving lever  177  coupled with the guide plate  176  pushes a lever end  156  formed on the cleaning lever  150 . 
     Then, as shown in of  FIG. 9A , the cleaning lever  150  positioned at the first position by the lever spring  158  moves to the second position as shown in of  FIG. 9B . 
     The guide projection part  154  moves along the first rail  192  formed in an oblique direction, and the cleaner  152  protrudes in the first housing  102 . The guide projection part  154  then moves along the second rail  194  and the cleaner  152  cleans the sensor. That is, the cleaner  152  cleans at least one of the first sensor  130  and the second sensor  132 . The second rail  194  may be formed in a direction parallel to the transferring path P. The stopper  195  contacts the guide projection part  154  to limit the movement of the cleaning lever  150 . 
     The cleaner  152  may be a material of a flexible material such as felt, woven fabric, non-woven fabric, knit, band and the like. 
     The guide block  185  may be formed to be inclined in an oblique direction, that is, the transferring path P, to guide the movement of the cleaner  152  when the cleaner  152  moves. 
     Thereafter, the cleaning lever  150  is repositioned to the first position by the restoring force of the lever spring  158 , and the cleaning operation may be repeated in an appropriate number. 
     According to the sensor cleaning device and the image forming apparatus including the same according to the present disclosure, the cleaning lever is positioned in the housing and does not affect the movement of the printing medium passing through the transferring path, and the sensor may be cleaned automatically when no copying or printing operation is performed. 
     Further examples of the present disclosure are described below. 
     A sensor cleaning device according to further examples of the present disclosure may clean a sensor for detecting a printable medium on a transferring path, the sensor cleaning device may include a cleaning lever coupled to a cleaner at an end and a driver coupled to the cleaning lever to drive the cleaning lever to move the cleaner from a first position to a second positon and back to the first position, the first position being away from the transferring path and the second position being in contact with the sensor. 
     According to further examples of the present disclosure, the sensor cleaning device may further include a guide rail disposed adjacent to the transferring path and a guide projection part coupled to the cleaning lever in contact with the guide rail to guide movement of the cleaning lever. 
     According to further examples of the present disclosure, the guide rail may include a first rail inclined to the transferring path to protrude the cleaning lever and a second rail parallel to the transferring path to guide the cleaning lever so the cleaner is to contact the sensor and clean the sensor. 
     According to further examples of the present disclosure, the sensor cleaning device may further include a lever spring to provide the cleaning lever with restoring force in the first position direction. 
     According to further examples of the present disclosure, the sensor cleaning device may further include a guide block located adjacent to the guide rail to guide movement of the cleaner. 
     According to further examples of the present disclosure, the driver may include a guide plate coupled to a driving lever to drive the cleaning lever, and a movable driving shaft insertable into a driving groove located in the guide plate, the guide plate being movable to a driving guider. 
     According to further examples of the present disclosure, the driving guider may include a guide shaft disposed along a direction of the first position and the second position, wherein the guide shaft being insertable to a guide groove formed to the guide plate. 
     An image forming apparatus according to further examples of the present disclosure may include a sensor disposed toward a transferring path on a first side of the transferring path to which a printing medium is moved and a cleaning device including a cleaning lever coupled to a cleaner to clean the sensor, and a driver coupled to the cleaning lever to drive the cleaning lever. 
     According to further examples of the present disclosure, the cleaner may move from a first position to a second position and back to the first position, the first position being away from the transferring path and the second position being in contact with the sensor. 
     According to further examples of the present disclosure, the image forming apparatus may further include a second sensor disposed toward the transferring path on a second side of the transferring path to which a printing medium is moved, the second side being different from the first side. The sensor may include a light emitting portion disposed on the first side of the transferring path to irradiate light toward the printing medium and the second sensor comprises a light receiving portion disposed on a second side of the transferring path to face the light emitting portion, and the cleaner may clean the light emitting portion and/or the light receiving portion. 
     According to further examples of the present disclosure, the first position may be the position where the cleaner and the cleaning lever deviate from the transferring path so as not to interfere with the movement of the printing medium. 
     According to further examples of the present disclosure, the second position may be the position on the transferring path where the cleaner cleans the light emitting portion and/or the light receiving portion. 
     According to further examples of the present disclosure, the image forming apparatus may include a processer to detect operating states of the light emitting portion and the light receiving portion and control an operation of the driver. 
     According to further examples of the present disclosure, the processer may control the operation of the driver so that the cleaner is in the first position when the printing medium passes on the transferring path, and the cleaner is in the second position to clean the sensor if there is no printing medium on the transferring path. 
     According to further examples of the present disclosure, the image forming apparatus may further include a memory to communicate with the processer. 
     According to further examples of the present disclosure, the processer may operate the driver when a number of operations stored in the memory exceeds a predetermined number of operations or when a sensitivity of the light emitting portion or the light receiving portion is less than a predetermined sensitivity. 
     According to further examples of the present disclosure, the image forming apparatus may further include a guide rail disposed to adjacent the transferring path and a guide projection part coupled to the cleaning lever to contact the guide rail to guide movement of the cleaning lever. 
     According to further examples of the present disclosure, the guide rail may include a first rail inclined to the transferring path to protrude the cleaning lever and a second rail parallel to the transferring path to guide the cleaning lever so the cleaner is to contact the sensor and clean the sensor. 
     While this disclosure has been described in connection with what is presently considered to be practical examples, it is to be understood that the disclosure is not limited to the disclosed examples. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.