Patent Application
20140014084
1. Field of the Invention
This application relates generally to an appliance controller and, more specifically, to a water-resistant, touch-sensitive controller for receiving input commands for controlling an aspect of an appliance.
2. Description of Related Art
Current capacitive touch electronics found in appliances can become insensitive or non-responsive to being contacted by a finger on which moisture has collected. Additionally, during the cooking process it is common for liquids such as water to boil over or otherwise splash out of a cooking vessel. When such liquids land on a conventional capacitive sensor they can alter the sensed capacitance, possibly inputting a signal that affects an operational feature of the appliance without knowledge/interaction by the user.
Attempts to alleviate the impact of moisture on an array of capacitive touch sensors have traditionally involved depositing a dedicated copper shield surrounding the array. The shield is dedicated to counteracting parasitic capacitance, and conducts a signal to negate the parasitic capacitance caused by the presence of conductive liquid droplets on the touch surface. Offsetting this parasitic capacitance with the dedicated shield located externally of the array of touch sensors allows the system to detect an actual touch in the presences of the liquid on the touch surface. As electronic circuits become smaller and more technology is added to appliances, there is often insufficient space available to deposit the dedicated shield outside of the array of touch sensors.
Accordingly, there is a need in the art for a touch-sensitive system that mitigates an effect of a conductive liquid present on a surface of the touch-sensitive system. The system includes a capacitive sensor that includes a plurality of adjacent capacitive, touch-sensing regions, each for detecting a user-input instruction to control operation of a component of an appliance. The touch-sensitive system can mitigate the effect of the conductive liquid without a conductive shield adjacent to the plurality of touch-sensing regions dedicated, or dedicated at least primarily for conducting a signal to counteract parasitic capacitance.
According to one aspect, the subject application involves a touch-sensitive input apparatus that includes a capacitive sensor including a plurality of adjacent capacitive, touch-sensing regions for detecting a foreign object in close proximity to a surface of the capacitive sensor. The foreign object can be brought into contact with, or at least in close proximity to the surface to enter an instruction for controlling a device associated with the touch-sensitive input apparatus. A controller is operatively connected to the plurality of touch-sensing regions to receive a signal indicative of a capacitance sensed by a first region included in the plurality of touch-sensing regions during application of a shield signal to a second region included in the plurality of touch-sensing regions. The second region is immediately adjacent to the first region.
According to another aspect, the subject application involves a method of sensing an input utilizing a capacitive sensor. According to such an aspect, the capacitive sensor includes a plurality of adjacent capacitive, touch-sensing regions for detecting a foreign object in close proximity to a surface of the capacitive sensor and receiving a user-input instruction for controlling a device associated with the touch-sensitive input apparatus. The method of the present aspect includes designating a first region included in the plurality of touch-sensing regions as an active sensor that is to sense a capacitance value for determining whether the foreign object is located adjacent to the first region. A second region included in the plurality of touch-sensing regions is designated as a shield sensor to which a shield signal is to be applied. The second region can be immediately adjacent to the first region. A signal indicative of the capacitance value sensed by the first region while the shield signal is applied to the second region is received. The second region can then be designated as the active sensor that is to sense another capacitance value for determining whether the foreign object is located adjacent to the second region. A second signal indicative of the capacitance value sensed by the second region while the shield signal is applied to at least one of the plurality of touch-sensing regions is also received.
According to another aspect, the subject application involves a cooking appliance that includes a heating device that is operable to elevate a temperature of a food item. A support is provided to maintain a position of the food item adjacent to the heating device. A capacitive sensor is also provided, and includes a plurality of adjacent capacitive, touch-sensing regions for detecting a foreign object in close proximity to a surface of the capacitive sensor entering an instruction to control operation of the heating device. A controller is operatively connected to the plurality of touch-sensing regions to receive a signal indicative of a capacitance sensed by a first region included in the plurality of touch-sensing regions during application of a shield signal to a second region included in the plurality of touch-sensing regions. The second region is immediately adjacent to the first region.
The above summary presents a simplified summary in order to provide a basic understanding of some aspects of the systems and/or methods discussed herein. This summary is not an extensive overview of the systems and/or methods discussed herein. It is not intended to identify key/critical elements or to delineate the scope of such systems and/or methods. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.
The invention may take physical form in certain parts and arrangement of parts, embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein:
Certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention. Relative language used herein is best understood with reference to the drawings, in which like numerals are used to identify like or similar items. Further, in the drawings, certain features may be shown in somewhat schematic form.
It is also to be noted that the phrase “at least one of”, if used herein, followed by a plurality of members herein means one of the members, or a combination of more than one of the members. For example, the phrase “at least one of a first widget and a second widget” means in the present application: the first widget, the second widget, or the first widget and the second widget. Likewise, “at least one of a first widget, a second widget and a third widget” means in the present application: the first widget, the second widget, the third widget, the first widget and the second widget, the first widget and the third widget, the second widget and the third widget, or the first widget and the second widget and the third widget.
The touch-sensitive input apparatus 12 can include a decorative overlay 20 visible to a user facing the cooking appliance 10 from the front. The decorative overlay 20 presents a graphical user interface to the user of the cooking device 10. The embodiment of the decorative overlay 20 in
As mentioned, the pattern formed by the touch-sensing regions 24 can be substantially continuous. The finger can be moved from a first touch-sensing region 24 to a second, contiguous touch-sensing region 24 as part of a continuous motion, optionally without encountering any extended gaps of dielectric material between the first and second touch-sensing regions 24. For instance, with reference to the embodiment of the capacitive sensor 26 shown in
An alternate embodiment of a pattern of the touch-sensing regions 24 of the capacitive sensor 26 is shown in
Although an arcuate pattern and a linear pattern have been shown and described, other desired layouts of the touch-sensing regions 24 are also considered within the scope of the present disclosure.
Referring once again to
Regardless of its configuration, the controller 32 is operable to receive signals from the capacitive sensor 26 and determine whether an instruction has been input based on the received signals. The controller 32 is also operable to designate one or more of the touch-sensing regions 24 that can sense a capacitance corresponding to an instruction input with the user's finger as a shield sensor. A shield signal is caused to be applied to the touch-sensing region 24 designated as the shield sensor as described below to shield an immediately-adjacent touch-sensing region 24 that is actively sensing a capacitance corresponding to an instruction input to control operation of a portion of the cooking appliance 10.
Using one or more of the touch-sensing regions 24, when not actively being used to sense a capacitance indicative of an instruction, as a shield sensor eliminates the need for a separate shield 34 dedicated primarily for shielding purposes, such as that shown in broken lines in
An illustrative embodiment of a method of sensing an input utilizing the capacitive sensor 26 can be understood with reference to the flow diagram appearing in
To shield against the effect of any substance such as water, for example, present at a surface of the decorative overlay 20 or otherwise close enough to the touch-sensitive input apparatus 12 to affect the capacitance value sensed by the active region, the controller 32 designates an adjacent touch-sensing region 24B as a shield sensor at step 110. A shield signal is applied to each shield sensor while the active sensor senses the capacitance value that is to be transmitted to the controller 32 for detecting the input of an instruction as described herein. It is not necessary for the shield signal to be applied simultaneously with the sensing operation performed by the active sensor. Instead, the shield signal can be previously applied to the shield sensor and maintained while the capacitance value is sensed by the active sensor. For the embodiment shown in
According to an alternate embodiment, the controller 32 can also optionally designate, at step 120, an additional, third touch-sensing region 24D included among the plurality of touch-sensing regions 24 as another shield sensor to which a shield signal is to be applied to shield the active sensor while the active sensor senses the capacitance value. The third touch-sensing region 24D is a different one of the touch-sensing regions 24 than the touch-sensing region 24B designated as a shield sensor. And according to the embodiment shown in
The designation of a second shield sensor can optionally be dependent upon the availability of another one of the touch-sensing regions 24 on an opposite side of the active sensor relative to the first shield sensor designated. For instance, the embodiment of the capacitive sensor 26 shown in
According to an alternate embodiment, the controller 32 can optionally designate the touch-sensing region 24G in
As mentioned above, a shield signal is being applied to each shield sensor at step 130, optionally under the control of the controller 32, while the active sensor is being used to sense the capacitance value. The controller 32, at step 140, can scan the active sensor and retrieve the signal indicative of the capacitance value sensed by the active sensor while the controller 32 is acting in an active mode, or otherwise receive a transmitted signal indicative of the sensed capacitance value while the controller 32 is acting in a passive mode. At step 150, based at least in part on this signal received, the controller 32 determines whether the capacitance value corresponds to the presence of the user's finger on or near the surface of the decorative overlay 20 at a location corresponding to touch-sensing region 24 that transmitted the signal. If so, the controller 32 can, at step 160, transmit a control signal for bringing about the desired change to an operational feature of the cooking appliance 10 (e.g., adjusting the power supplied to a heating element 14), or log the capacitance value until an additional capacitance value is sensed by one or more of the adjacent touch-sensing regions 24 to determine a direction, and optionally a distance along the capacitive sensor 26 the user's finger is being moved to input the instruction before transmitting the control signal, for example. The method can resume following the reaction to a received instruction.
If the determination at step 150 is negative, the method resumes without transmission of the control signal to bring about any changes with respect to an operational feature of the cooking appliance 10. At step 170, all of the shield sensors are disabled, which involves terminating application of the shield signal to those shield sensors. The controller 32 can also adjust the counter by incrementing or decrementing the counter, for example, to designate the next one of the touch-sensing regions 24 as the active sensor. With continued reference to the illustrative embodiment shown in
Although the method is described with reference to
Illustrative embodiments have been described, hereinabove. It will be apparent to those skilled in the art that the above devices and methods may incorporate changes and modifications without departing from the general scope of this invention. It is intended to include all such modifications and alterations within the scope of the present invention. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.
