Patent Publication Number: US-11039730-B2

Title: Dishwashing appliance with moisture-resistant capacitive touch sensor

Description:
FIELD 
     The present subject matter relates generally to user inputs for appliances, such as touch sensors for dishwashing appliances. 
     BACKGROUND 
     Appliances generally include a control panel having a plurality of buttons, keys, or other input devices. Utilizing the control panel, an appliance user can input control commands to the appliance and operate the appliance. Certain control panels include capacitive touch sensors that utilize a user&#39;s body capacitance to operate. In particular, capacitive touch sensors can detect a change in capacitance when the user touches the control panel. 
     Capacitive touch sensors have various benefits. For example, capacitive touch sensors can assist with providing a clean appearance for an associated appliance. In particular, capacitive touch sensors are frequently positioned behind a dielectric panel. A user touches an outer surface of the dielectric panel opposite the capacitive touch sensors to actuate the capacitive touch sensors. The smooth outer surface can have a pleasant cosmetic appearance, e.g., particularly compared to tactile buttons, knobs, etc. 
     Some capacitive touch sensors can register a “false touch,” e.g., when something other than the user touches the sensors or the dielectric panel such capacitive touch sensors may be actuated in an undesirable manner. For example, water or other liquids splashed or spilled on the control panel may cause capacitive touch sensors of the control panel to register a false touch. 
     Dishwashing appliances generally include a tub that defines a wash chamber. Rack assemblies can be mounted within the wash chamber for receipt of articles for washing. Various cycles may be included as part of the overall cleaning process. For example, a typical, user-selected cleaning option may include a wash cycle and rinse cycle (referred to collectively as a wet cycle), as well as a drying cycle. In addition, spray-arm assemblies within the wash chamber may be used to apply or direct fluid towards the articles disposed within the rack assemblies in order to clean such articles. As is generally understood, dishwashing appliances may often include multiple spray-arm assemblies, such as a lower spray-arm assembly mounted to the tub at a bottom of the wash chamber, a mid-level spray-arm assembly mounted to one of the rack assemblies, and/or an upper spray-arm assembly mounted to the tub at a top of the wash chamber. 
     While it is desirable to incorporate a capacitive touch sensor or sensors in a dishwashing appliance for the above-noted reasons, it is also challenging to do so given the presence of water and other liquids utilized by such appliances, e.g., during a wash cycle and/or rinse cycle, as mentioned above. 
     Accordingly, an improved capacitive touch sensor for an appliance would be welcomed, in particular, a capacitive touch sensor with improved resistance to moisture, e.g., water and/or wash liquids, for use in a dishwashing appliance would be welcomed. 
     BRIEF DESCRIPTION 
     Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention. 
     In one aspect, the present subject matter is directed to a dishwashing appliance. The dishwashing appliance includes a cabinet and a tub in the cabinet. The tub defines a wash chamber for receipt of articles for washing. A door is rotatably mounted to the cabinet for movement between a closed position wherein the wash chamber is sealingly enclosed and an open position permitting access to the wash chamber for loading and unloading of articles from the dishwashing appliance. The dishwashing appliance also includes a control console positioned on the door. The control console includes a console cover on an exterior surface of the door, a console bracket mounted within an interior of the door and proximate the console cover, and a circuit board attached to an interior surface of the console cover with a double-sided adhesive film. The double-sided adhesive film sealingly engages the console cover and the console bracket. 
     In another aspect, the present subject matter is directed to a dishwashing appliance. The dishwashing appliance includes a cabinet. The cabinet defines a vertical direction, a lateral direction, and a transverse direction that are mutually perpendicular. A tub is located in the cabinet. The tub defines a wash chamber for receipt of articles for washing. A door is rotatably mounted to the cabinet for movement between a closed vertical position wherein the wash chamber is sealingly enclosed and an open position permitting access to the wash chamber for loading and unloading of articles from the dishwashing appliance. The dishwashing appliance also includes a control console positioned on the door. The control console includes a console cover on an exterior surface of the door. The exterior surface of the door faces upward along the vertical direction when the door is in the closed position. The control console also includes a console bracket mounted within an interior of the door and below the console cover along the vertical direction when the door is in the closed position and a circuit board attached to an interior surface of the console cover with a double-sided adhesive film. The double-sided adhesive film sealingly engages the console cover and the console bracket. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures. 
         FIG. 1  illustrates a front view of one embodiment of a dishwashing appliance in accordance with aspects of the present subject matter. 
         FIG. 2  illustrates a cross-sectional side view of the dishwashing appliance shown in  FIG. 1 , particularly illustrating various internal components of the dishwashing appliance. 
         FIG. 3  illustrates a cross-sectional side view of a portion of a door of the dishwashing appliance of  FIG. 1  according to one or more embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
     As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows. As used herein, terms of approximation such as “generally,” “about,” or “approximately” include values within ten percent greater or less than the stated value. When used in the context of an angle or direction, such terms include within ten degrees greater or less than the stated angle or direction, e.g., “generally vertical” includes forming an angle of up to ten degrees in any direction, e.g., clockwise or counterclockwise, with the vertical direction V. 
     Referring now to the drawings,  FIGS. 1 and 2  illustrate one embodiment of a domestic dishwashing appliance  100  that may be configured in accordance with aspects of the present disclosure. As shown in  FIGS. 1 and 2 , the dishwashing appliance  100  may include a cabinet  102  having a tub  104  therein defining a wash chamber  106 . The tub  104  may generally include a front opening (not shown) and a door  108  hinged at its bottom  110  for movement between a normally closed vertical position (shown in  FIGS. 1 through 3 ), wherein the wash chamber  106  is sealed shut for washing operation, and a horizontal open position for loading and unloading of articles from the dishwashing appliance  100 . 
     As is understood, the tub  104  may generally have a rectangular cross-section defined by various wall panels or walls. For example, as shown in  FIG. 2 , the tub  104  may include a top wall  160  and a bottom wall  162  spaced apart from one another along a vertical direction V of the dishwashing appliance  100 . Additionally, the tub  104  may include a plurality of sidewalls  164  (e.g., four sidewalls) extending between the top and bottom walls  160 ,  162 . It should be appreciated that the tub  104  may generally be formed from any suitable material. However, in several embodiments, the tub  104  may be formed from a ferritic material, such as stainless steel, or a polymeric material. 
     As particularly shown in  FIG. 2 , upper and lower guide rails  124 ,  126  may be mounted on opposing side walls  164  of the tub  104  and may be configured to accommodate roller-equipped rack assemblies  130  and  132 . Each of the rack assemblies  130 ,  132  may be fabricated into lattice structures including a plurality of elongated members  134  (for clarity of illustration, not all elongated members making up assemblies  130  and  132  are shown in  FIG. 2 ). Additionally, each rack  130 ,  132  may be adapted for movement along a transverse direction T between an extended loading position (not shown) in which the rack is substantially positioned outside the wash chamber  106 , and a retracted position (shown in  FIGS. 1 and 2 ) in which the rack is located inside the wash chamber  106 . This may be facilitated by rollers  135  and  139 , for example, mounted onto racks  130  and  132 , respectively. As is generally understood, a silverware basket (not shown) may be removably attached to rack assembly  132  for placement of silverware, utensils, and the like, that are otherwise too small to be accommodated by the racks  130 ,  132 . 
     Additionally, the dishwashing appliance  100  may also include a lower spray-arm assembly  144  that is configured to be rotatably mounted within a lower region  146  of the wash chamber  106  directly above the bottom wall  162  of the tub  104  so as to rotate in relatively close proximity to the rack assembly  132 . As shown in  FIG. 2 , a mid-level spray-arm assembly  148  may be located in an upper region of the wash chamber  106 , such as by being located in close proximity to the upper rack  130 . Moreover, an upper spray assembly  150  may be located above the upper rack  130 . 
     As is generally understood, the lower and mid-level spray-arm assemblies  144 ,  148  and the upper spray assembly  150  may generally form part of a fluid circulation system  152  for circulating fluid (e.g., water and dishwashing fluid which may also include water, detergent, and/or other additives, and may be referred to as wash liquor) within the tub  104 . As shown in  FIG. 2 , the fluid circulation system  152  may also include a recirculation pump  154  located in a machinery compartment  140  below the bottom wall  162  of the tub  104 , as is generally recognized in the art, and one or more fluid conduits for circulating the fluid delivered from the pump  154  to and/or throughout the wash chamber  106 . The tub  104  may include a sump  142  positioned at a bottom of the wash chamber  106  for receiving fluid from the wash chamber  106 . The recirculation pump  154  receives fluid from sump  142  to provide a flow to fluid circulation system  152 , which may include a switching valve or diverter (not shown) to select flow to one or more of the lower and mid-level spray-arm assemblies  144 ,  148  and the upper spray assembly  150 . 
     Moreover, each spray-arm assembly  144 ,  148  may include an arrangement of discharge ports or orifices for directing washing liquid onto dishes or other articles located in rack assemblies  130  and  132 , which may provide a rotational force by virtue of washing fluid flowing through the discharge ports. The resultant rotation of the lower spray-arm assembly  144  provides coverage of dishes and other dishwasher contents with a washing spray. 
     A drain pump  156  may also be provided in the machinery compartment  140  and in fluid communication with the sump  142 . The drain pump  156  may be in fluid communication with an external drain (not shown) to discharge fluid, e.g., used wash liquid, from the sump  142 . 
     The dishwashing appliance  100  may be further equipped with a controller  137  configured to regulate operation of the dishwasher  100 . The controller  137  may generally include one or more memory devices and one or more microprocessors, such as one or more general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. 
     The controller  137  may be positioned in a variety of locations throughout dishwashing appliance  100 . In the illustrated embodiment, the controller  137  is located within a control panel area  121  of the door  108 , as shown in  FIG. 1 . In such an embodiment, input/output (“I/O”) signals may be routed between the control system and various operational components of the dishwashing appliance  100  along wiring harnesses that may be routed through the bottom of the door  108 . Typically, the controller  137  includes a user interface panel/control console  136  through which a user may select various operational features and modes and monitor progress of the dishwasher  100 . In one embodiment, the control console  136  may represent a general purpose I/O (“GPIO”) device or functional block. Additionally, the control console  136  may include input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, touch pads, and touch screens. The control console  136  may also include a display component, such as a digital or analog display device designed to provide operational feedback to a user. As is generally understood, the control console  136  may be in communication with the controller  137  via one or more signal lines or shared communication busses. It should be noted that controllers  137  as disclosed herein are capable of and may be operable to perform any methods and associated method steps as disclosed herein. 
     It should be appreciated that the present subject matter is not limited to any particular style, model, or configuration of dishwashing appliance. The exemplary embodiment depicted in  FIGS. 1 and 2  is simply provided for illustrative purposes only. For example, different locations may be provided for the control console  136 , different configurations may be provided for the racks  130 ,  132 , and other differences may be applied as well. 
       FIG. 3  provides an enlarged view of a portion of the door  108 , with the door  108  in the closed position. As illustrated in  FIG. 3 , the door  108  includes the control console  136  positioned on the door  108  such that the control console  136  forms a portion of an exterior surface  109  of the door  108 . As may be seen in  FIG. 3 , the door  108  extends from a front panel  111  to a back panel  112 , e.g., along the transverse direction T when in the closed position as illustrated in  FIG. 3 . An interior  113  of the door  108  is defined between the front panel  111 , the back panel  112 , the exterior surface  109 , and the bottom  110  ( FIG. 2 ) of the door  108 . The control console  136  includes a console cover  200 . The console cover  200  is positioned on and at least partially defines the exterior surface  109  of the door  108 . The exterior surface  109  generally faces upward along the vertical direction V when the door  108  is in the closed position. For example, the control console  136  may be positioned on a top surface of the door  108 , e.g., as illustrated in  FIG. 3  where, when in the closed position, the exterior surface  109  is located at an uppermost extent of the door  108  along the vertical direction V. 
     Still referring to  FIG. 3 , the control console  136  also includes a console bracket  202  mounted within the interior  113  of the door  108  proximate the console cover  200 . For example, the console bracket  202  may be mounted below the console cover  200  along the vertical direction V when the door  108  is in the closed position. The console bracket  202  extends in a first direction, e.g., the transverse direction T when the door  108  is in the closed position as illustrated in  FIG. 3 , from a front side  206  proximate the front panel  111  of the door  108  to a back side  208  proximate the back panel  112  of the door  108 . The console bracket  202  also includes a base  204  extending from the front side  206  to the back side  208 . In at least some embodiments, the front side  206  may be joined to the back side  208  through the base  204 , whereby the console bracket  202  provides a continuous single structure which can be mounted or mountable to the door  108  (such as at the front and back panels  111  and  112 ) to support and position the remaining components of the control console  136 . The console bracket  202  may be mounted to the door  108  at the front panel  111  and the back panel  112 , e.g., the front side  206  of the console bracket  202  may be coupled to the front panel  111 , e.g., with one or more mechanical fasteners (not shown) or adhesive, etc. and the back side  208  of the console bracket  202  may also be coupled to the back panel  112  of the door  108 , such as with mechanical fasteners, adhesives, or any other suitable coupling as will be understood by those of skill in the art. 
     The control console  136  may be or include a capacitive touch sensor. For example, the control console  136  may include a printed circuit board  212  comprising one or more capacitive touch sensors embedded thereon, and the console cover  200  may comprise a dielectric material such that the console cover  200  provides a dielectric panel for the capacitive touch sensor(s). For example, as is generally understood by those of skill in the art, the printed circuit board  212  may include an electrode, e.g., a ground pour of the printed circuit board  212 , and a sensor pad or pads disposed on the printed circuit board  212 . Accordingly, the control console  136  may be responsive to a touch from a user, e.g., on the exterior surface  109 , by sensing or measuring a change in capacitance at the printed circuit board  212  due to the presence of, e.g., the user&#39;s finger on the exterior surface  109 . In various embodiments, the capacitive touch sensor may operate on self capacitance, mutual capacitance, or combinations thereof and/or any other suitable configuration. The structure and function of such capacitive touch sensors are generally understood by those of skill in the art and, as such, are not shown or described in greater detail herein. 
     The printed circuit board  212  may be attached to the console cover  200  by an adhesive film, e.g., tape,  214 , as illustrated in  FIG. 3 . The adhesive film  214  may be double-sided, e.g., may have adhesive on two opposing surfaces of the film  214 . The printed circuit board  212  may be attached to an interior surface  210  of the console cover  200  by the adhesive film  214 . The interior surface  210  may, e.g., oppose and face away from the exterior surface  109  of the door  108 . It should be noted that the film  214  is illustrated with an exaggerated size relative to the surrounding components in  FIG. 3  for the sake of clarity of illustration. In practice, the film  214  may typically be much thinner, e.g., relative to the printed circuit board  212  and the console cover  200 , than is depicted in  FIG. 3 . The printed circuit board  212  may be encompassed within the console bracket  202 , e.g., the console bracket  202  may completely surround the printed circuit board  212  on at least three sides. As shown in  FIG. 3 , the double-sided adhesive film  214  may extend across both the front side  206  and the back side  208  of the console bracket  202 . The double-sided adhesive film  214  may also extend between the console bracket  202  and the console cover  200 . For example, as illustrated in  FIG. 3 , the double-sided adhesive film  214  may extend into the console cover to console bracket joint and may contact or engage each of the console cover  200  and the console bracket  202 . Thus, the double-sided adhesive film  214  may sealingly engage the console cover  200  and the console bracket  202 . As a result of such sealing engagement, the tape or film  214  may form a first seal  218  between the front side  206  of the console bracket  202  and the console cover  200  and may form a second seal  216  between the back side  208  of the console bracket  202  and the console cover  200 . The first seal  218  and the second seal  216  may be coplanar, e.g., the adhesive film  214  may be disposed entirely or substantially (e.g., at least 90%) within a single plane, such as along the interior surface  210  of the console cover  200 . The first seal  218  and the second seal  216  may reduce or prevent moisture, e.g., water and/or wash liquor, from entering into the console bracket  202 , thus avoiding or minimizing interference with the operation of the control console  136 . For example, in embodiments where the control console  136  includes capacitive touch sensor(s), short circuits or false touches may be reduced or prevented by the first seal  218  and the second seal  216 . Advantageously, providing the first seal  218  and the second seal  216  with the double-sided adhesive film  214  which is used to attach the printed circuit board  212  to the console cover  200  permits sealing between the console cover  200  and the console bracket  202  without additional parts and with a relatively simple construction. 
     The control console  136  of the present disclosure provides several advantages. For example, forming the seals  216  and  218  between the console bracket  202  and the console cover  200  with the double-sided adhesive film  214  which attaches the printed circuit board  212  to the console cover  200  provides a sealing engagement between the console bracket  202  and the console cover  200  without needing the console bracket  202  to extend beyond the interior surface  210  of the console cover  200 , e.g., along the vertical direction V when the door  108  is in the closed position. Accordingly, the console cover  200  may provide a smooth and uninterrupted surface for user engagement, e.g., a smooth and uninterrupted touch surface of the capacitive touch sensor in at least some embodiments. Such uninterrupted surface may be advantageous at least in aesthetics and may also reduce the possibility of debris accumulation on the control console  136 , e.g., by reducing the number and size of seams or crevasses in which debris may accumulate. As another example, such design may reduce the overall number of parts in the control console  136  assembly, e.g., by eliminating a need for additional separate sealing components. Accordingly, the printed circuit board  212  may be larger and may thereby provide increased size of the touch surface, e.g., in some embodiments a larger portion of the top surface  109  of the door  108  may be usable as the touch surface than would be possible if additional sealing elements were included. For example, the console cover  200 , including the touch-responsive exterior surface  109  defined thereby, may extend from the front panel  111  of the door  108  to the back panel  112  of the door  108 . As another example, the console bracket  202  may be positioned entirely within the interior  113  of the door  108 , e.g., without extending to or forming a part of the exterior surface  109  of the door  108 . 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.