MX2015001216A - Proximity switch assembly and activation method having virtual button mode. - Google Patents

Abstract

A proximity switch assembly and method for detecting activation of a proximity switch assembly is provided. The assembly includes a plurality of proximity switches each having a proximity sensor providing a sense activation field and control circuitry processing the activation field of each proximity switch to sense activation. The control circuitry controls the activation field of each proximity switch to sense activation, monitors signals indicative of the activation field, and determines a first stable signal amplitude and a subsequent second signal amplitude, and generates an activation output when the second stable signal amplitude exceeds the first stable amplitude by a known amount.

Description

ASSEMBLY OF A PROXIMITY SWITCH AND A METHOD OF ACTIVATION THAT HAS A VIRTUAL BUTTON MODE CROSS REFERENCE WITH A RELATED APPLICATION This application is a continuation in part of U.S. Patent Application No. 13 / 444,393, filed on April 11, 2012, entitled "ASSEMBLY OF THE PROXIMITY SWITCH AND AN ACTIVATION METHOD IN AN EXPLORING MODE." The related application mentioned above is hereby incorporated by reference.

FIELD OF THE INVENTION The present invention relates generally to switches and, more specifically, relates to proximity switches having an enhanced determination of switch activation.

BACKGROUND OF THE INVENTION Motor vehicles are usually equipped with several switches that can be activated by a user, such as switches to operate devices that include electric windows, headlights, windshield wipers, lunar roofs or sunroofs, interior lighting, radio and information and entertainment devices, and several other devices. Generally, it is necessary for a user to activate these types of switches in order to activate or deactivate a device or perform some type of control function. Proximity switches, such as capacitive switches, employ one or more proximity sensors to generate a detection activation field and detection changes in the activation field indicative of the user's actuation of the switch, normally generated by a finger of the user in close proximity or in contact with the sensor. The capacitive switches are normally configured to detect the operation of the switch by the user based on a comparison of the detection activation field with a threshold.

Switch assemblies frequently employ a plurality of capacitive switches in close proximity to each other and generally require a user to select a single capacitive switch desired to perform the intended operation. In some applications, such as use in a car, the driver of the vehicle has limited ability to see the switches due to driver distraction. In such applications, it is desired to allow the user to explore the switch assembly in search of a specific button while preventing the premature determination of switch activation. Thus, it is desired to detect if the user intends to activate a switch, or if he is simply scanning for a specific switch button while focusing on a higher priority task, such as driving, or if he does not intend to activate a switch. In this way, it is desired to provide a proximity switch arrangement that enhances the use of proximity switches by a person, such as the driver of a vehicle.

BRIEF DESCRIPTION OF THE INVENTION In accordance with one aspect of the present invention, a method of activating a proximity switch is provided. The method includes the steps of generating an activation field associated with each of a proximity sensor, and monitoring a signal indicative of each associated activation field. The method also includes the steps of determining a first amplitude when the signal is stable for a minimum period of time, and determining a second subsequent amplitude when the signal is stable for a minimum period of time. The method further includes the step of generating an activation emission when the second amplitude exceeds the first amplitude by a known amount.

In accordance with another aspect of the present invention, a method of activating a proximity switch is provided. The method includes the steps of generating a plurality of activation fields with a plurality of proximity sensors, and monitor the signals indicative of the activation fields. The method also includes the steps of detecting the sliding of a user's finger based on multiple signals and entering a scanning mode, determining a first stable amplitude during one of the signals over a period of time, and determining a second stable amplitude of a of the signs over a period of time. The method further includes the step of generating an activation field when the second stable amplitude exceeds the first stable amplitude by a known amount.

In accordance with a further aspect of the present invention, a proximity switch assembly is provided. The proximity switch assembly includes a plurality of proximity switches each providing a detection activation field. The proximity switch assembly further includes control circuitry that monitors the signals indicative of the activation fields, determines a first stable amplitude of the signal for a period of time, determines a second subsequent stable amplitude of the signal during a period of time. time, and generates an activation emission when the second stable signal exceeds the first stable signal by a known amount.

Those skilled in the art will understand and appreciate these and other aspects, objects, and attributes of the present invention after analyzing the following specification, claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is a perspective view of a passenger compartment of a motor vehicle having a top console employing a proximity switch assembly, according to one embodiment; FIG. 2 is an enlarged view of an upper console and a proximity switch assembly shown in FIG. 1; FIG. 3 is an enlarged cross-sectional view taken through line III-III in FIG. 2 showing a variety of proximity switches in relation to a user's finger; FIG. 4 is a schematic diagram of a capacitive sensor employed in each of the capacitive switches shown in FIG. 3; FIG. 5 is a block diagram illustrating the assembly of the proximity switch, according to one embodiment; FIG. 6 is a graph illustrating the signal count for a channel associated with a capacitive sensor showing an activation movement profile; FIG. 7 is a graph illustrating the signal count for two channels associated with the capacitive sensors showing a sliding scan / search movement profile; FIG. 8 is a graph illustrating the signal count for a signal channel associated with the capacitive sensors showing a slow motion profile of activation; FIG.9 is a graph illustrating the signal count for two channels associated with the capacitive sensors showing a fast sliding scan / search movement profile; FIG. 10 is a graph illustrating the signal count for three channels associated with the capacitive sensors in a scan / search mode illustrating a stable pressure activation at the peak, according to one embodiment; FIG. 11 is a graph illustrating the count of signals for three channels associated with the capacitive sensors in a scan / search mode illustrating the activation by stable pressure on a downward signal below the peak, according to another embodiment; FIG. 12 is a graph illustrating the signal count for three channels associated with capacitive sensors in a scan / search mode illustrating the highest stable pressure on a bearing to activate a switch, in accordance with a further embodiment; FIG. 13 is a graph illustrating the signal count for three channels associated with the capacitive sensors in a scan mode and the selection of a bearing based on the highest stable pressure, according to a further embodiment; FIG. 14 is a state diagram illustrating five states of the capacitive switch assembly implemented with a state machine, according to one embodiment; FIG. 15 is a flow chart illustrating a routine for executing a method of activating my switch assembly switch, in accordance with one embodiment; FIG. 16 is a flow chart illustrating the processing of the switch activation and the release of the switch; FIG. 17 is a flow chart illustrating the logic for switching between the neutral and active states of the switch; FIG. 18 is a flow diagram illustrating the logic for switching from an active state of the switch to the neutral state of the switch or switch threshold; FIG. 19 is a flow diagram illustrating a routine for switching between the switch threshold states and the switch search mode; FIG. 20 is a flow chart illustrating a virtual button method that implements the search state of the switch; FIG.21 is a graph illustrating the signal count for a channel associated with a capacitive sensor having a scan mode and a virtual button mode for activating a switch, according to a further embodiment; FIG.22 is a graph illustrating the count of signals for the virtual button mode in which an activation is not triggered; FIG. 23 is a graph illustrating the signal count for the capacitive sensor in scan mode which further illustrates the moment when the switch is activated, according to the embodiment of FIG. 21; FIG. 24 is a graph illustrating the signal count for a capacitive sensor which further illustrates the moment when the activations are triggered, according to the embodiment of FIG.21; FIG.25 is a graph illustrating the signal count for a capacitive sensor that further illustrates a pause to exit virtual button mode and re-enter virtual button mode, according to the embodiment of FIG.21; FIG. 26 is a flow diagram illustrating a routine for processing the signal channel with a virtual button mode, according to the embodiment shown in FIG.21; Y FIG. 27 is a flow chart illustrating a virtual button method for processing the signal channel, according to the embodiment of FIG. twenty-one.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As required, detailed embodiments of the present invention are disclosed herein; however, it will be understood that the disclosed embodiments are merely by way of example of the invention, which may be performed in various ways and in alternative ways. The figures are not necessarily for a detailed design; some schemes they can be exaggerated or minimized to show generalities of their function. Therefore, the specific structural and functional details disclosed herein are not construed as limiting, but merely as a representative basis for teaching a skilled person in the art the varied use of the present invention.

With reference to FIGS. 1 and 2, the interior of a motor vehicle 10 is generally illustrated with a passenger compartment and a switch assembly 20 employing a plurality of proximity switches 22 having monitoring and determination of switch activation, in accordance with an embodiment . The vehicle 10 generally includes an upper console 12 mounted to the interior trim of the roof over the lower part of the roof or maximum height in the upper part of the passenger compartment of the vehicle, generally above the front passenger seating area. The switch assembly 20 has a plurality of proximity switches 22 arranged close to each other in the upper console 12, according to one embodiment. The various proximity switches 22 can control any number of devices and functions of the vehicle, such as controlling the movement of a sunroof or a moon roof 16, controlling the movement of a moon-roof screen 18, controlling the activation of one or more lighting devices such as interior and dome 30 reading / reading map and various other devices and various other functions. However, it should be appreciated that the proximity switches 22 can be located in some other part of the vehicle 10, such as the dashboard, in other consoles such as in a central console, integrated in a touch screen monitor 14 for a system radio or information and entertainment, or elsewhere on board vehicle 10 according to various vehicle applications.

Proximity switches 22 are shown and described herein as capacitive switches, in accordance with one embodiment. Each proximity switch 22 includes at least one proximity sensor that provides a detection trigger field for detecting contact or close proximity (eg, within one millimeter) of a user relative to the one or more sensors of the sensor. proximity, such as a sweeping motion performed by a user's finger. Thus, the detection activation field of each proximity switch 22 is a capacitive field in the exemplary embodiment and the user's finger has electrical conductivity and dielectric properties that produce a change or modification in the detection activation field as it will be evident for those people trained in the technique. However, those skilled in the art should appreciate that alternative or additional types of proximity sensors can be used, such as, but not limited to, inductive sensors, optical sensors, temperature sensors, resistive sensors, the like or a combination of the previous Proximity sensors by way of example are described in the text of April 9, 2009, ATMEL® Touch Sensors Design Guide, 10620 D-AT42-04 / 09, the complete reference of which is incorporated herein by reference.

The proximity switches 22 shown in FIGS. 1 and 2 each provide control of a component or device of the vehicle or provide a designated control function. One or more of the proximity switches 22 can be dedicated to controlling the movement of a sunroof or a moon roof 16 in order to make the moonroof 16 move in an open or closed direction, tilt the moon roof, or stop the movement of the moon ceiling based on a control algorithm. One or more other proximity switches 22 can be dedicated to controlling the movement of a moon roof screen 18 between the open and closed positions. Each of the moon roof 16 and the screen 18 can be operated by an electric motor in response to the operation of the corresponding proximity switch 22. Other proximity switches 22 can be dedicated to controlling other devices, such as turning on a map reading / reading light. interior 30, turn off an interior map reading / reading light 30, turn a dome light on or off, unlock a trunk, open a rear hatch, or turn off a door light switch. Additional controls by means of the proximity switches 22 may include operating to raise and lower the electric windows of the doors. Various other controls of the vehicle can be controlled by means of the proximity switches 22 described herein.

With reference to FIG. 3, a portion of the proximity switch assembly 20 having an arrangement of three proximity switches 22 arranged sequentially in close relationship to each other relative to a user's finger 34 during use of the switch assembly 20 is illustrated. Proximity switch 22 includes one or more proximity sensors 24 to generate a detection trigger field. According to one embodiment, each of the proximity sensors 24 can be formed by conductive ink for printing on the upper surface of the polymeric upper console 12.

An example of a proximity sensor with printed ink 24 is shown in FIG. 4 which generally has a conductive electrode 26 and a receiving electrode 28 each with interdigitated fingers to generate a capacitive field 32. It should be appreciated that each of the proximity sensors 24 can be formed in another way such as by mounting a trace of a conducting circuit made on a substrate according to other embodiments. The conductive electrode 26 receives square wave conductive pulses applied to a voltage Vj. The receiving electrode 28 has an emission to generate an emission voltage V0. It should be appreciated that the electrodes 26 and 28 may be arranged in various other configurations to generate the capacitive field as the activation field 32.

In the embodiment shown and described herein, the conductive electrode 26 of each proximity sensor 24 is applied with voltage supply V, such as square wave pulses having a sufficient charge pulse cycle to charge the voltage. receiving electrode 28 to a desired voltage. The receiving electrode 28 therefore serves as a measuring electrode. In the embodiment shown, the adjacent detection activation fields 32 generated by the adjacent proximity switches 22 overlap slightly, however, the overlap may not exist in accordance with other embodiments. When a user or operator, such as the finger of the user 34, enters an activation field 32, the assembly of the proximity switch 20 detects the alteration caused by the finger 34 to the activation field 32 and determines whether the alteration is sufficient to activate the corresponding proximity switch 22. The alteration of the activation field 32 is detected by the processing of the charge pulse signal associated with the corresponding signal channel. When the finger of the user 34 contacts two activation fields 32, the assembly of the proximity switch 20 detects the alteration of both activated activation fields 32 by means of separate signal channels. Each proximity switch 22 has its own unique signal channel that generates charge pulse counts which is processed as described herein.

With reference to FIG. 5, the assembly of the proximity switch 20 is illustrated according to one embodiment. A plurality of proximity sensors 24 is shown which provides inputs to a controller 40, such as a microcontroller. The controller 40 may include control circuits, such as a microprocessor 42 and a memory 48. The control circuits may include detection control circuits that process the activation field of each sensor 22 to detect user activation of the corresponding switch by comparing the activation field signal with one or more thresholds according to one or more routines of control. It should be noted that other control circuits, analog and / or digital, can be used to process each activation field, determine the activation of the user and initiate an action. The controller 40 may employ a QMatrix acquisition method available through ATMEL®, in accordance with one embodiment. The ATMEL acquisition method uses a C / C ++ compiler from the WINDOWS® central system and the WinAVR debugger program to simplify the development and analysis of the Hawkeye utility, which allows real-time monitoring of the internal state of critical variables in the software. of data records for further processing.

The controller 40 provides an emission signal to one or more devices that are configured to perform exclusive actions in response to the successful activation of a proximity switch. For example, the one or more devices may include a moon roof 16 that has a motor for moving the moon roof panel between the open and closed and tilted positions, a moon roof screen 18 that moves between the open and closed positions, and the lighting devices 30 that can be turned on and off. Other devices such as a radio can be controlled to perform on and off functions, volume control, scanning and other types of devices to perform other exclusive functions. One of the proximity switches 22 can exclusively drive the moon roof closed, another proximity switch 22 can exclusively operate the open moon roof, and an additional switch 22 can exclusively operate the moon roof until reaching a tilted position, all of which cause An engine moves the moon roof to a desired position. The moon roof screen 18 can be opened in response to a proximity switch 22 and can be closed in response to another proximity switch 22.

It is shown that the controller 40 further has an analog-to-digital (A / D) comparator 44 coupled to the microprocessor 42. The A / D comparator 44 receives the voltage emission V0 from each of the proximity switches 22, converts the signal analog signal in a digital signal and provides the digital signal to the microprocessor 42. In addition, the controller 40 includes a pulse counter 46 coupled to the microprocessor 42. The pulse counter 46 counts the pulses of the charge signal that are applied to each conducting electrode of each proximity sensor, it counts the pulses necessary to charge the capacitor until the VQ voltage emission reaches a predetermined voltage, and provides the count to the microprocessor 42. The pulse count is indicative of the change in capacitance of the corresponding capacitive sensor. The controller 40 is further shown in communication with a pulse width modulated conduction buffer 15. The controller 40 provides a pulse width modulated signal to the pulse amplitude modulated conduction buffer 15 to generate a train of square wave pulses. Vj which is applied to each conductive electrode of each proximity switch / sensor 22. The controller 40 processes a control routine 100 stored in the memory to monitor and make a determination regarding the activation of one of the proximity switches.

In FIGS. 6-13, the change in the sensor load pulse counts that are shown as Sensor Count D for a plurality of signal channels associated with a plurality of proximity switches 22, such as the three switches 22 shown in FIG. FIG. 3, is illustrated according to several examples. The change in the sensor pulse count is the difference between a reference count value initialized without the presence of a finger or other object in the activation field and the corresponding sensor reading. In these examples, the user's finger enters the activation fields 32 associated with each of three proximity switches 22, generally one activation of the detection field at a time with overlap between the adjacent activation fields 32 while the user's finger it moves through a switch arrangement. Channel 1 is the change (D) in the count of charge pulses of the sensor associated with a first capacitive sensor 24, channel 2 is the change in the pulse count of the sensor associated with the second adjacent capacitive sensor 24, and channel 3 is the change in the charge pulse count of the sensor associated with the third capacitive sensor 24 adjacent to the second capacitive sensor. In the disclosed embodiment, the proximity sensors 24 are capacitive sensors. When a finger of the user is in contact with, or in close proximity to, a sensor 24, the finger alters the capacitance measured on the corresponding sensor 24. The capacitance is in parallel with the capacitance parasitic of the sensor bearing without touching, and in this way, it is measured as compensation. Capacitance induced by the user or by the operator is proportional to the user's finger or the dielectric constant of another part of the body, the surface exposed to the capacitive bearing, and is inversely proportional to the distance from the user's end to the switch button. According to one embodiment, each sensor is energized with a train of voltage pulses by means of pulse width modulation (PWM) electronics until the sensor is charged to a given potential voltage. Said acquisition method charges the receiving electrode 28 to a known voltage potential. The cycle is repeated until the voltage across the measuring capacitor reaches a predetermined voltage. Placing a user's finger on the touch surface of switch 24 introduces the external capacitance which increases the amount of charge transferred in each cycle, thereby reducing the total number of cycles required for the measurement capacitance to reach the predetermined voltage. The user's finger causes the change in the sensor pulse count to increase since this value is based on the initialized reference count minus the sensor reading.

The mounting of the proximity switch 20 is able to recognize the movement of the user's hand when the hand, in particular a finger, is in close proximity to the proximity switches 22, to discriminate if the user's intention is to activate a switch 22, scan for a specific switch button while focusing on priority tasks, such as driving, or is the result of a task such as adjusting the rearview mirror that has nothing to do with the operation of a proximity switch 22. The proximity switch assembly 20 can operate in a scan or search mode that allows the user to scan the keypads or buttons by passing or sliding a finger in close proximity to the switches without activating a switch activation until determined by the user's intent . The mounting of the proximity switch 20 monitors the amplitude of a signal generated in response to the activation field, determines a differential change in the generated signal, and generates an activation emission when the differential signal exceeds a threshold. As a result, scanning of the proximity switch assembly 20 is allowed, so that users have the freedom to explore the switch interface pad with their fingers without inadvertently triggering the episode, the response time of the interface is fast, the activation occurs when the finger contacts the surface panel and the involuntary activation of the switch is prevented or reduced.

With reference to FIG. 6, when the finger of the user 34 approaches the switch 22 associated with the signal channel 1, the finger 34 enters the activation field 32 associated with the sensor 24 which produces an interruption to the capacitance, thereby producing an increase in the count of the sensor as shown by the signal 50A having a normal activation movement profile. An inclined inlet plane slope method can be used to determine whether the operator intends to press a button or scan the interface based on the slope of the input inclined plane in signal 50 A of the channel 1 signal that arises from point 52 where the signal 50A crosses the active count of the level (LVL ACTIVE) to the point 54 where the signal 50 A crosses the threshold count of the level (LVL THRESHOLD), according to one embodiment. The slope of the input inclined plane is the differential change in the signal generated between points 52 and 54 that occurred during the time period between times t [h and tac. Since the threshold level - active level of the numerator generally changes only when the presence of gloves is detected, although otherwise it remains constant, the slope can be calculated only as the time elapsed to cross from active level to threshold level, referred to as tactile Ve2threshoid, what is the difference between time? L and tac. A direct pressure on a switch bearing can normally occur in a period of time referred to as tdirectpush in the range of about 40 tao to 60 thousandths of a second. If the tactiV2threshold time is less than or equal to the tdjrectpush direct pressure time, it is determined that the switch activation occurs. Otherwise, it is determined that the switch is in a scan mode.

According to another embodiment, the slope of the input inclined plane can be computed as the difference in time from time tac at point 52 to time tpk to reach the peak count value at point 56, referred to as tactive2peak time. The time tgctiveipeakP11® ^ ® compared with a direct pressure peak, referred to as ^ d¡rect_push_pk F * e It can have a value of 100 milliseconds according to one embodiment. If the time tactive2peak is less than or equal to the tdirectjushjk it is determined that activation occurs. Otherwise, the switch assembly operates in a scan mode.

In the example shown in FIG. 6, the signal of channel 1 is shown to increase as the alteration of the capacitance increases rapidly rising from point 52 to the peak value at point 56. The assembly of proximity switch 20 determines the slope of the input inclined plane as any period of time tactjve2threshold or tactive2Peak To flue the signal from a first threshold point 52 to either the second threshold point 54 or the peak threshold at point 56. The slope or differential change in the generated signal is used for comparison with a representative direct pressure threshold tdirectJush or tdjrectjushjk to determine the activation of the proximity switch. Specifically, when the time tactive2peak is less than the tdjrectjush or tactive2threshoid it is less than ctjush 'the activation of the switch is determined. Otherwise, the switch assembly remains in the scan mode.

With reference to FIG. 7, an example of a sliding / scanning movement through the switches is illustrated as the finger passes or slides through the activation field of two adjacent proximity sensors which are shown as signal channel 1 labeled 50 A and the signal channel 2 labeled 50B. When the user's finger approaches a first switch, the finger enters the activation field associated with the first switch sensor causing the change in the sensor count on signal 50A to increase at a slower rate so that it is determined a reduced differential change in the generated signal. In this example, the profile of the signal channel 1 undergoes a change in time tactive2peak which is not less than or equal to tdirectjush, thus resulting in entering the search or scan mode. Since the tactive2threshoid is indicative of a slow differential change in the generated signal, activation of the switch button is not initiated, according to one embodiment. According to another embodiment, since the time tactive2peak is not less than or equal to tdirectjushj) k, indicative of a slow differential change in a generated signal, activation is not initiated, according to another embodiment. The second signal channel labeled 50B is shown to be transformed into the maximum signal at the transition point 58 and has an increasing change in the Sensor Count D with a differential change in the signal similar to that of the signal 50A. As a result, the first and second channels 50A and 50B reflect a sliding motion of the finger through two sensors capacitive in the exploration mode which does not produce activation of any of the switches. With the use of the tactive2threshold or tactjve2peak time period, a decision can be made to activate or not a proximity switch when its capacitance level reaches the peak of the signal.

For a slow movement of direct pressure as shown in FIG. 8, additional processing may be employed to ensure that activation is not sought. As shown in Fig. 8, the signal channel 1 identified as signal 50A is shown with a slower elevation during any time period tactive2threshold or tactive2peak which would result in entering the scan mode. When such sliding / scanning is detected, with time tactive2threshold greater than tdirect_push if the channel that does not meet the condition was the first signal channel that enters the exploration mode and is still the maximum channel (the channel with the highest intensity) and that its capacitance falls below LVL_KEYUP_Threshold at point 60, then the activation of the switch is initiated.

With reference to FIG. 9, a quick movement of a user's finger through the proximity switch assembly is illustrated without activation of the switches. In this example, the relatively large differential change in the signal generated for channels 1 and 2 is detected, for both channels 1 and 2 shown by lines 50A and 50B, respectively. The switch assembly employs a delayed period of time to delay the activation of a decision to the transition point 58 in which the second signal channel 50B rises above the first signal channel 50A. It could be determined that the delay in time is equal to the time threshold tdirect hk according to one embodiment. Thus, by employing a delay period before determining the activation of a switch, very fast scanning of keyboards by proximity prevents unintentional activation of a switch. The introduction of the delay in response can make the interface less sensitive and work better when the movement of the operator's finger is substantially uniform.

If a previous threshold event that did not trigger was recently detected, it can be automatically entered into the scan mode, according to one embodiment. As a result, once an inadvertent actuation is detected and rejected, more caution may be applied for a period of time in the scanning mode.

Another way to allow an operator to enter the scan mode is to use one or more areas or bearings marked and / or appropriately textured on the surface of the switch panel associated with the exclusive proximity switches with the function of signaling the switch assembly proximity of the operator's intention to explore blindly. The one or more scan start bearings can be located in an easily accessible location to generate activity with other signal channels. According to another embodiment, a larger, unmarked scanning bearing that surrounds the entire switch interface can be employed. Said scanning bearing would probably first be encountered when the operator's hand slides across the edge in the upper console in search of a mark from which to start the blind exploration of the proximity switch assembly.

Once the proximity sensor assembly determines whether an increase in the change in the sensor count is to the activation of the switch or the result of a scan mode, the assembly proceeds to determine if, and how, the scanning movement should terminate or not in an activation of the proximity switch. According to one embodiment, the proximity switch assembly seeks stable pressure on the switch button for at least a predetermined amount of time. In a specific embodiment, the predetermined amount of time is equal to or greater than 50 thousandths of a second, and more preferably about 80 thousandths of a second. Examples of the operation of the switch assembly employing a stable time methodology are illustrated in FIGS. 10-13.

With reference to FIG. 10, the scanning of three proximity switches corresponding to the signal channels 1-3 labeled 50A-50C signals, respectively, is illustrated, while one finger slides through the first and second switches in the scan mode and then activates the third switch associated with signal channel 3. When the finger scans the first and second switches associated with channels 1 and 2, activation is not determined because there is no stable signal on lines 50A and 50B. The signal on line 50 A for channel 1 starts as the maximum value of the signal until channel 2 on line 50B becomes the maximum value and finally channel 3 becomes the maximum value. It is shown that signal channel 3 has a stable change in the count of the sensor near the peak value for a sufficiently long period of time such as 80 milliseconds which is sufficient to initiate the activation of the corresponding proximity switch. When the condition of activating the level threshold has been met and a peak has been reached, the stable level method activates the switch after the level in the switch is within a narrow range for at least the tstable time period It allows the operator to scan the various proximity switches and activate a desired switch once it is found by maintaining the position of the user's finger in proximity to the switch for a stable period of stable time.

With reference to FIG. 11, another embodiment of the stable level method is illustrated in which the third signal channel on the line 50C has a change in the count of the sensor which has a stable condition on the signal descent. In this example, the change in the count of the sensor for the third channel exceeds the level threshold and has a stable pressure detected for a period of time tstaWe so that the activation of the third switch is determined.

According to another embodiment, the proximity switch assembly can employ a virtual button method that searches for an initial peak value of the change in the sensor count while in the scan mode followed by an additional sustained increase in the change in the count of the sensor to make a determination to activate the switch as shown in FIGS. 12 and 13. In FIG. 12, the third signal channel on the line 50C is raised to an initial peak value and then further increased by a change in the count of the Cvb sensor. This is equivalent to a user's finger gently combing the surface of the switch assembly as it slides through the switch assembly, reaching the desired button, and then pressing the virtual mechanical switch so that the user's finger presses the surface of the switch. switch contact and increase the amount of finger volume closer to the switch. The increase in capacitance is caused by the increase in the surface of the fingertip when it is compressed on the surface of the bearing. The increase in capacitance can occur immediately after detection of a peak value shown in FIG. 12 or may occur after a decline in the change in the sensor count as shown in FIG. 13. The proximity switch assembly detects a peak value initial followed by a further major change in the sensor count indicated by capacitance Cyb at a stable level or a stable stable time period. A stable level of detection generally means that there is no change in the value of the sensor count without noise or a small change in the value of the sensor count without noise that can be determined during calibration.

It should be appreciated that a shorter period of time can produce accidental activations, especially after an inversion in the direction of finger movement and that a longer period of time can produce a less sensitive interface.

It should be appreciated that both the stable value method and the virtual button method can be active at the same time. By doing so, the stable time t ^, can be relaxed to be longer, such as a second, since the operator can always activate the button using the virtual button method without waiting for a wait at stable pressure.

The proximity switch assembly can also employ a rejection of powerful noises to avoid inadvertent annoying operations. For example, with a top console, the opening and closing of the moon roof should be avoided. Too much noise rejection may end up rejecting the intended activations, which should be avoided. One approach to reject noise is to see if multiple adjacent channels report on simultaneous activation episodes and, if so, choose the signal channel with the highest signal and activate it, thus ignoring all other signal channels until the release of the selected signal channel.

The mounting of the proximity switch 20 may include a method of rejecting noise by attributes based on two parameters namely an attribute parameter which is the ratio between the channel between the highest intensity (max channel and the general cumulative level (sum channel) and the parameter dac which is the number of channels having at least a certain proportion of the max_channel In one embodiment, the dac adac = 0.5 The attribute parameter can be defined by the following equation: .. max channel maxi = 0 nchanneli attribute = - = - = - -. sum channel 2_, channel i = 0, n The dac parameter can be defined by the following equation: d, ac = Vchannels > ,, 1 < * max channel Depending on the dac, for a recognized activation that will not be rejected, the channel should generally be clean, that is, the attribute must be greater than a predefined threshold. In one embodiment, = 0.4, and «dac = 2 = 0.67. If the dac is greater than 2, the activation is rejected according to one embodiment.

When a decision is made to activate or not a switch in the downward phase of the profile, then instead of max channel and sum_channel its peak values max channel and peak_sum_channel can be used to calculate the attribute. The attribute can have the following equation: attribute _ max (max_channel (t)) peak sum channel max (sum_channel (t)) A search mode can be used that triggers rejection of noise. When a detected activation is rejected due to a dirty attribute, the search or scan mode must be activated automatically. Thus, when you explore blindly, a user can reach with all the extended fingers looking to establish a frame of reference from which to start the search. This can activate multiple channels at the same time, thus producing a deficient attribute.

With reference to FIG. 14, a state diagram for mounting the proximity switch 20 in an implementation of the state machine is shown, according to one embodiment. The implementation of the state machine is shown with five states including the state SW NONE 70, state SW_ACTIVE 72, state SW THRESHOLD 74, state SW_HUNTING 76 and state SWITCH_ACTIVATED 78. State SW_NONE 70 is the state in which it is not detected sensor activity. The SW_ACTIVE state is the state in which some activity is detected by the sensor, but not enough to activate the activation of the switch at that moment. The state SW_THRESHOLD is the state in which the activity as determined by the sensor is high enough to guarantee activation, search / exploration, or casual movement of the switch assembly. The state SW HU TING 76 is entered when the pattern of activity according to determined by mounting the switch is compatible with the exploration / search interaction. The state SWITCH_ACTIVATED 78 is the state in which the activation of a switch has been identified. In SWITCH ACTIVATED state 78, the switch button will remain active and no other selection will be possible until the corresponding switch is released.

The state of the mounting of the proximity switch 20 changes depending on the detection and processing of the detected signals. When in the SW_NONE 70 state, the system 20 can advance to the SW_ACTIVE state 72 when an activity is detected by one or more sensors. If sufficient activity is detected to indiscriminately command activation, search or casual movement, the system 20 can advance directly to the state SW_THRESHOLD 74. When it is in the SW THRESHOLD 74 state, the system 20 can advance to the SW HUNTING 76 status when an indicative scan pattern is detected or it can advance directly to the state of the activated switch 78. When the switch activation is in the SW HUNTING state, it can be detected that a switch activation changes to the state SWITCH ACTIVATED 78. If the signal is rejected and the involuntary action is detected, the system 20 can return to the state SW_NONE 70.

With reference to FIG. 15, the main method 100 of monitoring and determining when to generate an activation emission with the proximity switch arrangement is shown, according to one embodiment. Method 100 begins at step 102 and advances to step 104 to perform an initial calibration that can be performed once. The values of the calibrated signal channel are computed from the unprocessed data and the calibrated reference values by subtracting the reference value from the unprocessed data in step 106. Next, in step 108, of all the readings of the sensor of the signal channel, the highest count value referred to as max channel is calculated and the sum of all the channel sensor readings referred to as sum_channel is calculated. In addition, the number of active channels is determined. In step 110, the method 100 calculates the recent range of the max_channel and the sum_channel to determine later whether movement is in progress or not.

After step 110, method 100 proceeds to decision step 112 to determine if any of the switches are active. If no switch is active, the 100 method proceeds to step 114 to perform a real-time online calibration. Otherwise, method 116 processes the release of the switch in step 116. In this way, if a switch was already active, then method 100 advances to a module where it waits and locks up all activity until it is released.

After real-time calibration, the method 100 proceeds to the decision stage 118 to determine if there is any blocking of the channel indicative of recent activation and, if so, advances to step 120 to reduce the channel blocking timer. If channel blockages are not detected, the method 100 advances to the decision stage 122 to look for a new max_channel. If the current max channel has changed so that there is a new max channel, the method 100 advances to step 124 to reset the max_channel, add the ranges, and set the threshold levels. Thus, if a new max channel is identified, the method resets the recent signal ranges, and updates, if necessary, the search / scan parameters s. If the switch_status is less than SW ACTTVE, then the search / scan mark is set equal to real and the state of the switch is set equal to SW NONE. If the current max channel has not changed, the method 100 advances to step 126 to process the status of the max_channel with the bare finger (no glove). This may include processing the logic between the various states as shown in the state diagram of FIG. 14 After step 126, method 100 proceeds to decision stage 128 to determine if any switch is active. If switch activation is not detected, method 100 advances to step 130 to detect the possible presence of a glove in the hand of a user. The presence of a glove can be detected based on a reduced change in the counting value of the capacitance. The method 100 then advances to step 132 to update the past history of the max channel and sum channel. The index of the active switch, if any, is then output to the software and hardware module in step 134 before ending in step 136.

When a switch is active, a process switch release routine is activated as shown in FIG. 16. The process switch release routine 116 begins at step 140 and proceeds to decision stage 142 to determine if the active channel is less than LVL RELEASE and, if so, ends at step 152. If the channel active is less than the LVL RELEASE then the routine 116 proceeds to the decision stage 144 for determine if the LVL_DELTA_THRESHOLD is greater than 0 and, if not, advance to step 146 to raise the threshold level if the signal is stronger. This can be achieved by reducing LVL_DELTA_THRESHOLD. Step 146 also sets threshold, release and active levels. The routine 116 then proceeds to step 148 to reset the max and sum channel protocol timer for stable long parameters of search / scan of the signal. The state of the switch is set equal to SW NONE in step 150 before ending in step 152. To exit the process switch release module, the signal in the active channel must fall below LVL_RELEASE, which is a flexible threshold that will change when interaction with a glove is detected. When the switch button is released, all internal parameters are reset and a lock timer is started to prevent additional activations before a certain wait time has elapsed, such as 100 milliseconds. In addition, the threshold levels are adapted according to the presence of gloves or not.

With reference to FIG. 17, a routine 200 is illustrated to determine the state change from the SW_NONE state to the SW_ACTIVE state, according to one embodiment. The routine 200 begins at step 202 to process the state SW_NONE, and then proceeds to the decision stage 204 to determine whether the max channel is greater than LVL_ACT1VE. If the max channel is greater than LVL ACTIVE, then the proximity switch assembly changes status from the SW_NONE state to the ACTIVE SW state and ends at the step 210. If the max channel is not greater than LVL ACTIVE, the routine 200 controls for determine whether to restart the search mark in step 208 before ending in step 210. Thus, the state changes from the SW NONE state to the ACTIVE SW state when the max_channel is activated above LVL_ACTIVE. If the channel remains below this level, after a certain waiting period, the search mark, if set, is reset to no search, which is my way out of the search mode.

With reference to FIG. 18, a method 220 is illustrated for processing the state change of the SW ACTIVE state to either the SW THRESHOLD state or the SW NONE state, according to one embodiment. Method 220 starts at step 222 and proceeds to decision step 224. If the max channel is not greater than LVL THRESHOLD, then method 220 advances to step 226 to determine if the max channel is less than LVL ACTIVE and, if so, advance to step 228 to change the state of the switch to SW_NONE. From this way, the state of the state machine moves from the state SW_ACTIVE to the state SW_NONE when the signal of the max_channel falls below the LVL_ACTIYE. A delta value can also be subtracted from the LVL ACTIVE to introduce some hysteresis. If the max channel is greater than the LVL_THRESHOLD, then the routine 220 proceeds to the decision stage 230 to determine whether a recent threshold episode or glove has been detected and, if so, fixes the search on the mark equal to real in step 232. In step 234, method 220 switches the state to state SW_THRESHOLD before ending in step 236. Thus, if the max channel is activated above the LVL THRESHOLD, the state changes to state SW THRESHOLD. If gloves are detected or a previous threshold event that did not trigger was recently detected, then it can be automatically entered into search / scan mode.

With reference to FIG. 19, a method 240 for determining the activation of a SW THRESHOLD state switch, according to an embodiment, is illustrated. Method 240 starts in step 242 to process the SW_THRESHOLD state and advances to the decision block 244 to determine whether the signal is stable or if the signal channel is on a peak and, if not, it ends in step 256. whether the signal is stable or the signal channel is on a peak, then method 240 proceeds to decision stage 246 to determine whether the search or scan mode is active and, if so, skips to the step 250. If the search or scan mode is not active, the method 240 advances to the decision stage 248 to determine whether the signal channel is clear and fast active is greater than a threshold and, if so, to set the switch active equal to the maximum channel in step 250. Method 240 advances to decision block 252 to determine if there is an active switch and, if so, ends in step 256. If there is no active switch, method 240 advances until stage 254 to initialize the SWITCH STATUS search variables defined equal to SWITCH SEARCH and PEAK MAX BASE equal to MAX CHANNELS, before ending in step 256.

In the SW THRESHOLD state, no decision is made until a peak is detected in MAX_CHANNEL. Crest value detection is conditioned on either an inversion in the direction of the signal, or both MAX CHANNEL and SUM CHANNEL that remain stable (joined in a range) for at least a certain interval, such as 60 thousandths of a second. second. Once the peak is detected, it is verified the search brand. If the search mode is off, the slope method of the inclined plane is applied. If the ACTIVE SW to SW THRESHOLD was less than a threshold such as 16 thousandths of a second, and the attribute of the noise rejection method indicates it as a valid activation episode, then the status is changed to SWITCH ACTIVE and the process is transferred to the PROCESS SWITCH RELEASE module, otherwise the search mark is set equal to true. If the delayed action method is used instead of immediately activating the switch, the status is changed to SW_DELAYED_ACTIVATION where a delay is applied at the end of which, if the current MAX_CHANNEL index is not changed, the button is activated.

With reference to FIG. 20, a virtual button method that implements the SW HUNTING state is illustrated, in accordance with one embodiment. The method 260 begins at step 262 to process the SW HUNTING state and advances to the decision stage 264 to determine whether the max_channel has fallen below the LVL_KEYUP_THRESHOLD and, if so, set the MAX PEAK BASE equal to MIN (MAX_PEAK_BASE, MAX_CHANNEL) in step 272. If the MAX_CHANNEL has fallen below the LVL_KEYUP_THRESHOLD, then the method 260 advances to step 266 to employ the trigger search method of the first channel to control if the episode must activate the activation of the button. This is determined by determining if the first and only channel is traversed and if the signal is clean. If so, method 260 determines the active switch equal to the maximum channel in step 270 before ending in step 282. If the first and only channel is not traversed or if the signal is not clear, method 260 advances to the step 268 to leave and determine an involuntary activation and set the SWITCH STATUS equal to state SW NONE before ending at step 282.

After step 272, method 260 proceeds to decision step 274 to determine if the channel was selected with the button. This can be determined by whether MAX CHANNEL is greater than MAX_PEAK_BASE plus delta. If the channel was selected with the button, method 260 proceeds to decision stage 276 to determine whether the signal is stable and clean and, if so, sets the active switch state to the maximum channel in step 280 before end in step 282. If the channel has not been selected with the button, method 260 proceeds to decision stage 278 to see if the signal is long, stable and clean, and if so, advances to step 280 to set the active switch equal to the maximum channel before ending in step 282.

The mounting of the proximity switch 20 may include a virtual button mode, according to another embodiment. With reference to FIGS. 21-27, there is shown the mounting of the proximity switch having a virtual button mode and a method of activating the proximity switch with a virtual button mode, according to this embodiment. The proximity switch assembly may include one or more proximity switches providing each of a detection activation field and control circuits to control the activation field of each proximity switch to detect activation. The control circuits monitor the signals indicative of the activation fields, determine a first stable amplitude of the signal for a period of time, determine a second subsequent stable amplitude of the signal for a period of time, and generate an activation emission when the second stable signal exceeds the first stable signal by a known amount. The method can be employed by mounting the proximity switch and includes the steps of generating an activation field associated with each of one or more of a plurality of proximity sensors, and monitoring a signal indicative of each associated activation field. The method also includes the steps of determining a first amplitude when the signal is stable for a minimum period of time, and determining a second amplitude when the signal is stable for a minimum period of time. The method further includes the step of generating an activation emission when the second amplitude exceeds the first amplitude by a known amount. As a result, a virtual button mode is provided for the proximity switch that prevents or reduces false or unintentional activations that may be caused by finger scanning of a plurality of proximity switch and changing directions buttons or by a finger covered by a glove.

In FIG. 21, the scanning and activation of a proximity switch is shown for one of the signal channels marked as signal 50 when a user's finger slides through the corresponding switch, enters a scan mode, and advances to activate the switch at the virtual button mode. It should be appreciated that the user's finger can scan a plurality of capacitive switches as illustrated in FIGS. 10-12 in which the signals associated with each of the corresponding signal channels are generated when the finger passes through the activation field of each channel. A plurality of signal channels can be processed at the same time and the maximum signal of the channel can be processed to determine the activation of the corresponding proximity switch. In the examples provided in the signal diagrams of FIGS. 21-25, an individual signal channel associated with a switch is shown, however, a plurality of signal channels could be processed. The signal 50 associated with one of the signal channels is shown in FIG. 21 is raised to an active threshold level 320 at point 300 at which point the signal enters the scan mode. The signal 50 continues to rise upwards and reaches a first amplitude at which point the signal is stable for a minimum period of time, which is shown as Tstable which is shown at point 302. At point 302, signal 50 enters virtual button mode and establishes a first base value Cbase which is the count of the delta signal at point 302. In At this point, the virtual button mode establishes an increasing activation threshold as a function of the base value Cbase multiplied by a constant Kvb. The activation threshold to determine an activation can be represented by: (l + K ^) x Cbase, where it is a constant greater than zero. The virtual button mode continues to monitor the signal 50 to determine when it reaches a stable amplitude for a minimum period of time Tstable which occurs at point 304. At this point 304, the virtual button mode compares the second stable amplitude with the first stable amplitude and determines whether the second amplitude exceeds the first amplitude by the known amount of Kyb x Cbase. If the second amplitude exceeds the first amplitude by the known amount, an activation emission for the proximity switch is then generated.

According to this embodiment, the amplitude of the stable signal must be maintained by the signal channel for at least a minimum period of time Tstable before entering the virtual button mode or determining the interruption of the switch. The value of the sensor when entering virtual button mode is registered as Cbase. The method monitors to determine when a subsequent stable signal amplitude is achieved again before the waiting period. If the amplitude of the stable signal is again achieved before the waiting period that expires with a delta count value greater than a desired percentage, such as 12.5 percent of the previous registered Cbase, then activation is activated. Agree with one embodiment, an increase in the count percentage of the delta signal of at least 10 percent is provided by x Cbase.

The multiplier Kvb is a factor of at least 0.1 or at least 10 percent of the Cbase value, according to one embodiment. According to another embodiment, the multiplier is set to about 0.125 which is equivalent to 12.5 percent. The stable time period Tstable can be set at a time of at least 50 milliseconds, according to one embodiment. According to another embodiment, the stable time period Tstable can be set in the range of 50 to 100 thousandths of a second. The stable amplitude can be determined by the amplitude of the signal that is substantially stable in a range within twice the size of the estimated noise in the signal according to one embodiment, or within 2.5 to 5.0 percent of the level of the signal, according to another embodiment or a combination of twice the estimated noise of the signal added at 2.5 to 5.0 percent of the signal level, according to a further embodiment.

With reference to FIG. 22, a signal 50 is illustrated for a signal channel associated with a proximity switch by entering the scan mode at point 300 and advancing to reach a first stable amplitude when the amplitude of the stable signal exists for a minimum period of time Tstable in the point 302 in which the virtual button mode is entered. At this point, the Cbase value is determined. Thereafter, it is shown that the signal 50 falls and rises again to a second amplitude when the signal is stable for a minimum period of time Tstable at point 306. However, in this situation, the second amplitude at the point 306 does not exceed the base Cbase value of the signal at point 302 by the known amount of x Cbase, and as a result it does not generate a switch activation emission.

With reference to FIG. 23, a signal 50 associated with the signal channel entering scan mode at point 300 is illustrated and advances to reach a first amplitude for a stable time period Tstable at point 302 at which virtual button mode is entered and the Cbase is determined. Thereafter, signal 50 continues to rise to a second amplitude that is stable for a minimum period of time Tstable at point 308. However, at point 308, the second amplitude does not exceed the base value Cbase of the signal established in the first amplitude at point 302 by the known amount of Kvb x Cbase, so that the proximity switch assembly does not cause a switch output. However, a new updated base value is generated for Cbase at point 308 and is used to determine the known quantity for comparison to the next stable amplitude. It is shown that the signal 50 falls and then rises to a third amplitude which is stable for a minimum period of time Tstable at point 310. The third amplitude exceeds the second amplitude by more than the known quantity Kvb x Cbase, so that a switch activation output is generated.

With reference to FIG. 24, another example of a signal 50 entering scan mode at point 300 is illustrated and continuing to rise to a first amplitude that is stable for a minimum period of time Tstable at point 302 at which virtual button mode is entered. and the Cbase is determined. Since then, it is shown that the signal 50 falls to a second amplitude that is stable for a minimum period of time Tstable at point 312. At point 312, the second amplitude does not exceed the first amplitude by the known amount of Kyb x Cbase so that an activation of the signal is not generated. However, an updated base value Cbase is generated at point 312. Thereafter, the signal 50 continues to rise to a third amplitude that is stable for a minimum period of time Tstable at point 310. The third amplitude exceeds the second amplitude by the amount x Known Cbase, so that a trigger or switch activation output is generated.

With reference to FIG. 25, another example of a signal 50 is shown for a signal channel that enters the scan mode at point 300 and advances to reach a first amplitude that is stable for a minimum period of time Tstable at point 302 and therefore enters to virtual button mode and determines Cbase. Next, the signal 50 continues to rise to a second amplitude that is stable for a period of time Tstable at point 308. The second amplitude does not exceed the first amplitude by the known amount so that a switch activation is not generated in this point. Thereafter, it is shown that the signal 50 drops to point 314 and in the process, a restart timer rests since the last stable amplitude was received as shown by the Treset time. When the restart timer rests, at point 314, the virtual button mode is exited and the scan mode is entered once the virtual button mode is exited. When this occurs, the determined previous Chase is no longer valid. Thereafter, the signal 50 is shown to rise to a third amplitude which is stable for a minimum period of time Tstable at point 316. At this point, the third amplitude establishes an updated Cbase which is used to determine future activations of the switch. Thereafter, it is shown that the signal 50 falls further below the active threshold value 320, in which case, the virtual button mode is exited without any activation.

A method of activating a proximity switch with a virtual button mode by using the proximity switch assembly is illustrated in FIGS. 26 and 27. With reference to FIG. 26, method 400 begins at step 402 and proceeds to acquire all signal channels associated with all proximity switches in step 404. Method 400 advances to decision block 406 to determine whether the state is set to the state ACTIVE and, if so, controls to determine the release of the switch in step 414 before ending in step 416. If the state is not set to the ACTIVE state, method 400 advances to step 408 to find the maximum channel (CHT). Then, once the maximum channel has been found, routine 400 advances to step 410 to process the maximum channel virtual button (CHT) method before ending at step 416. The maximum channel virtual button method of process 410 is illustrated in FIG. 27 and described below. It should be appreciated that the method 400 may include an optional step 412 to also process the maximum channel signal by using the knock method to detect a user who hits a proximity switch or to generate an activation output.

The virtual button method of the maximum channel of the process 410 shown in FIG. 27 starts at step 420 and advances to step 422 to enter the maximum channel signal. Accordingly, the signal of the maximum channel associated with one of the proximity switches is processed to determine the state of the virtual button mode and the activation of the switch. In decision step 424, method 410 determines whether the switch is set to the state of the virtual button mode and, if so, advances to the decision step 426 to determine if the value of the signal channel is less than the threshold. active. If the signal channel is less than the active threshold, method 410 advances to step 428 to set the state equal to NONE and returns to the beginning. If the signal channel is not less than the active threshold value, method 410 proceeds to decision step 430 to determine whether the signal has a first stable amplitude for a period of time greater than the stable time period Tstable. If the stable signal channel in the first amplitude is stable for a period of time greater than Tstable, the method 410 proceeds to the decision step 432 to determine whether the signal channel is not stable for a period of time exceeding the reset time period Treset and, if not, returns to step 422. If the channel of The signal is not stable for a period of time exceeding the reset time period Treset, the method 410 advances to set the state equal to the scan / search state and ends at step 460.

Returning to decision step 430, if the signal channel is stable for a period of time exceeding the stable time period Tstable, method 410 proceeds to decision stage 436 to determine whether the signal Ch (t) is greater that Cbase by a known quantity defined by Kvb x Cbase and, if so, sets the state of the active switch to generate an activation output before ending in step 460. If the signal does not exceed Cbase by the known amount of Kvb x Cbase, method 410 advances to set a new value of Cbase to the current stable signal amplitude in step 440, before ending in step 460.

Returning to decision step 424, if the state of the switch is not set to virtual button mode, method 410 proceeds to decision step 442 to determine whether the state is set to the scan state and, if so, proceeds to decision step 444 to determine if the signal is greater than the active threshold and, if not, sets the state equal to the NONE state and ends at step 460. If the signal is greater than the active threshold, method 410 proceeds to decision step 448 to determine whether the signal is stable at an amplitude for a period of time exceeding the minimum time period Tstable and, if not, ends at step 460. If the signal is stable at an amplitude during a period of time exceeding the minimum time period Tstable, the method 410 advances to step 450 to set the state of the switch to the state of the virtual button and to set a new value of Cbase for the signal channel in step 450 before to finish in stage 460.

Returning to decision step 442, if the state of the switch is not set to the scan / search state, method 410 proceeds to decision step 452 to determine if the signal is greater than the active threshold and, if not, ends at step 460. If the signal is greater that the active threshold, the method 410 advances to the decision stage 454 to set the state in the scan / search state before ending in step 460.

In this way, the proximity switch assembly having the virtual button method 410 advantageously provides enhanced detection of the switch activation with virtual button and improved rejection of involuntary activations. The method 410 can advantageously detect an activation of a switch while rejecting the involuntary activations that can be detected when a finger explores the switch assembly and reverses the reverse direction or in which the user's finger uses a glove. The enhanced activation detection advantageously provides an enhanced proximity switch assembly.

In this way, the determination routine advantageously determines the activation of the proximity switches. The routine advantageously allows a user to explore the proximity switch bearings which can be particularly useful in an automotive application where distraction of the driver can be avoided.

It will be understood that variations and modifications to the aforementioned structure can be made without departing from the concepts of the present invention, and furthermore it will be understood that said concepts are intended to be covered by the following claims unless these claims express otherwise by means of their drafting.

Claims (20)

1. A method of activating a proximity switch, characterized in that it comprises: generate an activation field associated with a proximity sensor; monitor a signal indicative of the activation field; determining a first amplitude when the signal is stable for a minimum period of time; determining a second subsequent amplitude when the signal is stable for a minimum period of time; Y generate an activation emission when the second amplitude exceeds the first amplitude by a known quantity.

2. The method of claim 1 characterized in that it further comprises the step of detecting the slippage of an object in a scanning mode before determining the first and second amplitudes.

3. The method of claim 1, characterized in that the period of time is at least 50 milliseconds.

4. The method of claim 3, characterized in that the period of time is in the range of 50 to 100 thousandths of a second.

5. The method of claim 1, characterized in that the known amount comprises at least 110% of the first amplitude.

6. The method of claim 1, characterized in that, if the second amplitude does not exceed the first amplitude by the known amount, the method further determines when the signal is stable at a third amplitude, and when the third amplitude exceeds the second amplitude by the amount known, the activation output is generated.

7. The method of claim 1 further comprising monitoring the time from the first stable amplitude and requiring the determination of another stable amplitude before the expiration of the restart time before generating the activation output.

8. The method of claim 1, characterized in that the signal comprises a change in the count of the sensor associated with an activation field.

9. The method of claim 1, wherein the proximity switch is installed in a vehicle to be used by a passenger inside the vehicle.

10. The method of claim 1, characterized in that the proximity switch comprises a capacitive switch comprising one or more capacitive sensors.

11. The method of claim 1, characterized in that the method generates an activation field for each of a plurality of proximity sensors and monitors a signal indicative of each driving field and determines the first and second amplitude of the signal having the Greatest value

12. A method of activating a proximity switch, said method being characterized in that it comprises: generating a plurality of activation fields with a plurality of proximity sensors; monitor the signals indicative of the activation fields; detect the sliding of a user's finger based on multiple signals and enter a scan mode; determining a first stable amplitude during one of the signals over a period of time; determining a second stable amplitude of one of the signals over a period of time; Y generate an activation field when the second stable amplitude exceeds the first stable amplitude by a known quantity.

13. The method of claim 12, characterized in that the proximity switch is installed in a vehicle to be used by a passenger inside the vehicle.

14. The method of claim 12, characterized in that the proximity switch comprises a capacitive switch comprising one or more capacitive sensors.

15. The method of claim 12, characterized in that the period of time is at least 50 thousandths of a second.

16. The method of claim 15, characterized in that the period of time is in the range of 50 to 100 thousandths of a second.

17. An assembly of the proximity switch characterized in that it comprises: a plurality of proximity switches each providing a detection activation field; Y control circuitry monitoring signals indicative of the activation fields, determining a first stable amplitude of a signal for a period of time, determining a second subsequent stable amplitude of the signal for a period of time, and generating an activation output of a proximity switch when the second stable signal exceeds the first stable signal by a known amount.

18. The proximity switch assembly of claim 17, characterized in that the plurality of proximity switches are installed in a vehicle to be used by a passenger inside the vehicle.

19. The proximity switch assembly of claim 18, characterized in that the proximity switches comprise capacitive switches comprising one or more capacitive sensors.

20. The proximity switch assembly of claim 17, characterized in that the control circuitry determines the signal as the largest of the monitored signals.