CN105281737B

CN105281737B - Proximity switch assembly with slot between adjacent proximity sensors

Info

Publication number: CN105281737B
Application number: CN201510359027.4A
Authority: CN
Inventors: 摩晒陀·色姆萨若·达萨纳亚克; 彼得罗·布托洛; 斯图尔特·C·萨尔特
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2014-06-25
Filing date: 2015-06-25
Publication date: 2021-06-04
Anticipated expiration: 2035-06-25
Also published as: BR102015015181A2; MX2015008054A; MX351155B; DE102015109549A1; CN105281737A; RU2676913C2; TR201507630A2; RU2015125008A; RU2015125008A3

Abstract

A proximity switch assembly and a method for detecting activation of the proximity switch assembly are 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 flexible material covers the proximity sensor. The control circuit monitors the activation field and determines activation of the proximity switch based on a signal generated by the sensor when the user's finger presses the flexible material as compared to a threshold value. The flexible material may further include a raised portion and an air gap between the raised portion and the sensor.

Description

Proximity switch assembly with slot between adjacent proximity sensors

Cross Reference to Related Applications

The present application is a partial continuation application entitled "PROXIMITY SWITCH ASSEMBLY AND ACTIVATION METHOD WITH VIRTUAL BUTTON MODE" (a partial continuation application of the application entitled "PROXIMITY SWITCH ASSEMBLY AND ACTIVATION METHOD WITH VIRTUAL BUTTON MODE"), which is filed under the united states patent application No. 14/284,659, filed under the application date of 2014, 5, 22, 2014, entitled "flexible PROXIMITY SWITCH ASSEMBLY AND ACTIVATION METHOD (program SWITCH ASSEMBLY AND ACTIVATION METHOD)", which is a partial continuation application of the application under the application date of 2014, 1, 30, 2014, AND the application entitled "PROXIMITY SWITCH ASSEMBLY AND ACTIVATION METHOD WITH VIRTUAL BUTTON MODE" is a partial continuation application of the application under the application number 13/444,393, filed under the application date of 2012, 4, 11, AND filed under the application title of "PROXIMITY SWITCH ASSEMBLY AND ACTIVATION METHOD WITH EXPLORATION MODE)". The foregoing related applications are all incorporated herein by reference.

Technical Field

The present invention relates generally to switches and, more particularly, to a proximity switch with enhanced switch turn-on determination.

Background

Motor vehicles are typically equipped with various user-actuatable switches, such as switches for operating devices including power windows, headlamps, windshield wipers, sunroofs or skylights, interior lights, broadcast and infotainment devices, and various other devices. Generally, these types of switches need to be actuated by a user to turn the device on or off or to perform some type of control function. Proximity switches, such as capacitive switches, employ one or more proximity sensors to generate a sense activation field (sense activation field) and sense a change in the activation field indicative of a user actuating the switch, typically caused by a user's finger being in close proximity or touching the sensor. The capacitive switch is typically configured to detect a user actuated switch based on a comparison of the sensed turn-on field to a threshold.

Switch assemblies often employ multiple capacitive switches in close proximity to each other and generally require a user to select a single desired capacitive switch to perform the desired operation. In some applications, such as use in automobiles, the ability of the driver of the vehicle to view the switch is limited due to driver distraction. In these applications, it is desirable to allow the user to explore the switch assembly to find a particular button while avoiding premature determination of switch activation. Thus, there is a need to distinguish whether a user intends to turn on a switch, whether he is simply exploring a particular switch button while focusing on a high priority task such as driving, or whether he is inadvertently turning on a switch. Accordingly, there is a need to provide a proximity switch arrangement that enhances the use of the proximity switch by, for example, a vehicle driver.

Disclosure of Invention

According to one aspect of the present invention, a proximity switch assembly is provided. The proximity switch assembly includes a proximity sensor that generates an activation field, a flexible material covering the proximity sensor, and a control circuit that monitors the activation field and determines that the proximity switch is activated based on a signal generated by the sensor when a user's finger presses the flexible material as compared to a threshold value.

In accordance with another aspect of the present invention, a method of turning on a proximity switch is provided. The method includes the steps of generating an on field associated with the proximity sensor and monitoring a signal indicative of the on field. The method further includes the steps of determining an amplitude when the signal is stable for a minimum time and generating an on output when the amplitude exceeds the first amplitude by a known amount, the on output indicating that a user pressed a flexible material covering the proximity sensor.

According to the present invention, there is provided a proximity switch assembly comprising:

a rigid carrier having an upper surface and a bottom surface;

a first proximity sensor proximate to a surface of the carrier;

a second proximity sensor proximate to the surface of the carrier, adjacent to the first sensor, having an area therebetween;

a flexible material disposed on an upper surface of the carrier; and

a slot formed in the carrier in a region between the first and second proximity sensors.

According to an embodiment of the invention, wherein the slot has a dimension longer than the sensor.

According to one embodiment of the invention, the slot dimension exceeds the sensor by 5 to 10 mm.

According to an embodiment of the invention, wherein the flexible material is rubber.

According to an embodiment of the invention, wherein the groove has a thickness in the range of 0.5 to 2.0 mm.

According to one embodiment of the invention, the proximity switch assembly further comprises a control circuit that monitors an activation field associated with the proximity sensor and determines activation of the proximity switch based on a signal generated by the sensor about a threshold value when the flexible material is pressed by a finger of a user.

According to one embodiment of the invention, the proximity switch assembly further comprises a first recess formed on the rigid carrier between the flexible material and the first proximity sensor.

According to one embodiment of the invention, the proximity switch assembly further comprises a second recess formed on the rigid carrier between the flexible material and the second proximity sensor.

According to one embodiment of the invention, wherein the proximity switch comprises a capacitive switch comprising one or more capacitive sensors.

According to one embodiment of the invention, wherein the assembly is mounted on a vehicle.

According to the present invention, there is provided a vehicle proximity switch assembly comprising:

a rigid carrier having first and second surfaces;

a first proximity sensor mounted on a bottom surface of the carrier;

a second proximity sensor mounted on the bottom surface of the carrier adjacent the first sensor with an area therebetween;

a flexible material disposed on an upper surface of the carrier; and

According to one embodiment of the invention, the mesoslot has a dimension longer than the sensor.

According to one embodiment of the invention, the tap-in switch assembly further comprises a control circuit that monitors an activation field associated with the proximity sensor and determines activation of the proximity switch based on a signal generated by the sensor about a threshold value when the flexible material is pressed by a finger of a user.

These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.

Drawings

FIG. 1 is a perspective view of a passenger compartment of an automotive vehicle having an overhead console that employs a proximity switch assembly in accordance with one embodiment;

fig. 2 is an enlarged view of the overhead console and proximity switch assembly shown in fig. 1;

FIG. 3 is an enlarged cross-sectional view taken through line III-III of FIG. 2 showing the alignment of the proximity switch with respect to the user's finger;

FIG. 4 is a schematic diagram of a capacitive sensor employed by each of the capacitive switches shown in FIG. 3;

FIG. 5 is a block diagram illustrating a proximity switch assembly according to one embodiment;

FIG. 6 is a graph illustrating a signal count for one channel associated with a capacitive sensor, showing an opening motion curve;

FIG. 7 is a graph illustrating signal counts for two channels associated with a capacitive sensor, showing a sliding seek motion profile;

FIG. 8 is a graph illustrating signal counts of signal channels associated with a capacitive sensor showing a slow opening motion profile;

FIG. 9 is a graph illustrating signal counts for two channels associated with a capacitive sensor showing a fast slide exploration/search motion curve;

FIG. 10 is a graph illustrating signal counts for three channels associated with a capacitive sensor in an exploration/search mode illustrating a steady press on at peak according to an embodiment;

FIG. 11 is a graph illustrating signal counts for three channels associated with a capacitive sensor in an exploration/search mode illustrating a steady press on when the signal falls below a peak value, according to another embodiment;

FIG. 12 is a graph illustrating signal counts for three channels associated with a capacitive sensor in an exploration/search mode illustrating increased steady pressure on a keypad (pad) to open a switch, in accordance with yet another embodiment;

FIG. 13 is a graph illustrating signal counts for three channels associated with a capacitive sensor in an exploration mode, which selects a keypad according to increasing steady pressure, in accordance with yet another embodiment;

FIG. 14 is a state diagram illustrating five states of a capacitive switch assembly implemented with a state machine according to one embodiment;

FIG. 15 is a flow diagram illustrating a routine for performing a method of opening a switch of a switch assembly according to one embodiment;

FIG. 16 is a flow chart illustrating a switch on and switch off process;

FIG. 17 is a flow chart illustrating the logic for transitioning between the no-switch-on (switch none) and switch-on (switch active) states;

FIG. 18 is a flow chart illustrating the logic for transitioning from a switch ON state to a no switch ON state or a switch threshold state;

FIG. 19 is a flow diagram illustrative of a routine for transitioning between switch threshold and switch search states;

FIG. 20 is a flow chart illustrating a virtual button method of implementing a switch search state;

FIG. 21 is a graph illustrating signal counts for channels associated with a capacitive sensor having an exploration mode for opening a switch and a virtual button mode, in accordance with yet another embodiment;

FIG. 22 is a graph illustrating signal counts for a virtual button mode in which turn-on is not triggered;

FIG. 23 is a graph illustrating signal counts for a capacitive sensor in an exploration mode, further illustrating a switch being opened, according to the embodiment of FIG. 21;

FIG. 24 is a graph illustrating signal counts for the capacitive sensor according to the embodiment of FIG. 21, further illustrating that turn-on is triggered;

FIG. 25 is a graph illustrating signal counts for the capacitive sensor according to the embodiment of FIG. 21, further illustrating timeouts for exiting the virtual button mode and re-entering the virtual button mode;

FIG. 26 is a flow diagram illustrative of a routine for processing signal channels in the virtual button mode in accordance with the embodiment shown in FIG. 21;

FIG. 27 is a flow diagram illustrating a virtual button method of processing signal channels according to the embodiment of FIG. 21;

FIG. 28A is a cross-sectional view of a proximity switch assembly having a proximity switch and a covering flexible material relative to a user's finger shown in a first position in accordance with another embodiment;

FIG. 28B is a cross-sectional view of the proximity switch assembly of FIG. 28A, further illustrating the user's finger in a second position;

FIG. 28C is a cross-sectional view of the proximity switch assembly of FIG. 28A, further illustrating the finger pressing into the flexible layer in a third position;

FIG. 28D is a graph illustrating a signal generated by one of the proximity sensors in response to the movement of the finger and depression of the flexible cover shown in FIGS. 28A-28C;

FIG. 29A is a cross-sectional view of a proximity switch assembly and a user's finger shown in a first position, where the proximity switch assembly employs a flexible cover material having a raised area with an air gap, in accordance with yet another embodiment;

FIG. 29B is a cross-sectional view of the proximity switch assembly of FIG. 29A, further illustrating the user's finger in a second position;

FIG. 29C is a cross-sectional view of the proximity switch assembly shown in FIG. 29A, further illustrating the switch being depressed by a user's finger in a third position;

FIG. 29D is a graph illustrating a signal generated by one of the sensors in response to the movement of a finger as shown in FIGS. 29A-29C;

FIG. 30 is a state diagram illustrating various states of a capacitive switch assembly having a flexible material cover and a virtual button mode;

FIG. 31 is a flow diagram illustrating a routine for processing signals generated by a proximity switch covered with a flexible material according to one embodiment;

fig. 32 is a perspective cut-away view of a vehicle overhead console having a proximity switch assembly employing a recess and a flexible cover on a carrier in accordance with one embodiment;

fig. 33 is a top plan view of the overhead console and switch assembly of fig. 32, with the sensors and recesses shown in hidden dashed lines;

FIG. 34A is a cross-sectional view of the proximity switch assembly shown in FIG. 32 and a user's finger shown in a first position, in accordance with one embodiment;

FIG. 34B is a cross-sectional view of the proximity switch assembly of FIG. 34A, further illustrating the user's finger in a second position;

FIG. 34C is a cross-sectional view of the proximity switch assembly seen in FIG. 34A, further illustrating the switch being depressed by the user's finger in a third position;

FIG. 34D is a graph illustrating a signal generated by one of the proximity sensors in response to movement of the finger as shown in FIGS. 34A-34C;

fig. 35 is a perspective cut-away view of a vehicle overhead console having a proximity switch assembly employing slots between adjacent sensors in accordance with another embodiment;

fig. 36 is a top view of the overhead console and switch assembly of fig. 35 with the sensors, recesses and slots shown in hidden lines;

FIG. 37A is a cross-sectional view of the proximity switch assembly shown in FIG. 35 and a user's finger shown in a first position, in accordance with one embodiment;

FIG. 37B is a cross-sectional view of the proximity switch assembly of FIG. 37A, further illustrating the user's finger in a second position;

FIG. 37C is a cross-sectional view of the proximity switch assembly shown in FIG. 37A, further illustrating the user's finger in a third position;

FIG. 37D is a cross-sectional view of the proximity switch assembly seen in FIG. 37A, further illustrating the user's finger in a fourth position;

FIG. 37E is a graph illustrating two signals generated by two sensors in response to the movement of the finger shown in FIGS. 37A-37D; and

FIG. 38 is a cross-sectional view of a proximity switch assembly in accordance with yet another embodiment wherein the proximity switch assembly employs a flexible covering material having recesses and raised areas in the flexible material over each recess.

Detailed Description

As stated, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The drawings are not necessarily of a particular design; some diagrams may be enlarged or reduced to show a functional overview. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

Referring to fig. 1 and 2, an interior of a vehicle 10 is generally shown having a passenger compartment and a switch assembly 20, the switch assembly 20 employing a plurality of proximity switches 22, the proximity switches 22 having switch activation monitoring and determination, according to one embodiment. The vehicle 10 generally includes an overhead console 12 mounted on the roof or ceiling below the ceiling of the roof of the passenger compartment of the vehicle, generally above the front passenger seating area. According to one embodiment, the switch assembly 20 has a plurality of proximity switches 22 positioned adjacent to each other on the overhead console 12. The various proximity switches 22 may control any of a number of vehicle devices and functions, such as controlling movement of the sunroof or glass 16, controlling movement of the sunroof 18, controlling activation of one or more lighting devices, such as interior map/reading lights and overhead lights 30, and controlling various other devices and functions. However, it should be appreciated that the proximity switch 22 may be located elsewhere in the vehicle 10, such as in the dashboard, in other consoles, such as a center console, in touch screen displays 14 coupled to a broadcast or infotainment system, such as a navigation and/or audio display, or in other locations within the vehicle 10 depending on the different vehicle applications.

The proximity switch 22 is shown and described herein as a capacitive switch, according to one embodiment. Each proximity switch 22 includes at least one proximity sensor that provides a sense turn-on field to sense user contact or close proximity (e.g., within 1 millimeter) to one or more proximity sensors, such as the motion of a user's finger rubbing. Thus, in the exemplary embodiment the sensing activation field of each proximity switch 22 is a capacitive electric field, and it should be apparent to those skilled in the art that the user's finger has conductive and dielectric properties that cause variations and perturbations in the sensing activation field. However, those skilled in the art will recognize that additional or alternative types of proximity sensors may also be used, such as, but not limited to, inductive sensors, optical sensors, temperature sensors, resistive sensors, and the like, or combinations thereof. 4 and 9 days in 2009

An exemplary proximity sensor is described in the touch sensor design guide, 10620D-AT42-04/09, the entire contents of which are incorporated herein by reference.

The proximity switches 22 shown in fig. 1 and 2 each provide control of a vehicle component or device, or provide designated control functions. One or more proximity switches 22 may be dedicated to controlling movement of the skylight or skylight 16 to move the skylight 16 in an opening or closing direction, tilt the skylight, or stop movement of the skylight in accordance with a control algorithm. One or more other proximity switches 22 may be dedicated to controlling movement of the sunroof visor 18 between the open and closed positions. The sunroof 16 and visor 18 may each be actuated by a motor in response to actuation of a corresponding proximity switch 22. Other proximity switches 22 may be dedicated to controlling other devices, such as turning on the interior map/reading light 30, turning off the interior map/reading light 30, turning on or off a dome light, unlocking the trunk, turning on the rear doors, or eliminating the door light switch. Other controls via the proximity switch 22 may include actuating the door power window up or down. Various other vehicle controllers may be controlled by the proximity sensor 22 described herein.

Referring to fig. 3, there is shown a portion of the proximity switch assembly 20 relative to a user's finger 34 during use of the switch assembly 20 having an array of 3 proximity switches 22 in close proximity to each other in a sequential arrangement. Each proximity switch 22 includes one or more proximity sensors 24 for generating a sensing turn-on field. According to one embodiment, each proximity sensor 24 may be formed by printing conductive ink on the upper surface of the polymeric overhead console 12. An example of a printed ink proximity sensor 24 having generally drive electrodes 26 and receive electrodes 28 is shown in fig. 4, the drive electrodes 26 and receive electrodes 28 each having interdigitated fingers for generating a capacitive electric field 32. It should be appreciated that each proximity sensor 24 may be made in other ways, for example, by wire-mounting a pre-fabricated conductive circuit onto a carrier according to further embodiments. The driving electrode 26 receives a voltage V_IAn applied square wave drive pulse. The receiving electrode 28 has a voltage generating circuit for generating an output voltage V_OTo output of (c). It should be appreciated that the

electrodes

26 and 28 may be arranged in various other configurations to generate a capacitive electric field such as the turn-on field 32.

In the embodiment shown and described herein, a square wave pulse voltage input V is applied to the drive electrode 26 of each proximity sensor 24_IThe square wave pulse has a charging pulse period sufficient to charge the receiving electrode 28 to a desired voltage. The receiving electrode 28 thus functions as a measuring electrode. In the illustrated embodiment, the adjacent sense on fields 32 generated by adjacent proximity switches 22 slightly overlap, however, according to other embodiments, there may be no heavyAnd (5) stacking. When a user or operator, such as a user's finger 34, enters the opening field 32, the proximity switch assembly 20 detects the disturbance caused by the finger 34 to the opening field 32 and determines whether the disturbance is sufficient to open the corresponding proximity switch 22. The perturbation of the opening field 32 is detected by processing the charging pulse signal (charge pulse signal) associated with the corresponding signal channel (signal channel). When a user's finger 34 contacts both turn-on fields 32, the proximity switch assembly 20 detects the perturbation of both contacted turn-on fields 32 through separate signal channels. Each proximity switch 22 has its own dedicated signal channel that generates a charge pulse count that is processed as described herein.

Referring to fig. 5, a proximity switch assembly 20 is shown according to one embodiment. A plurality of proximity sensors 24 are shown providing input to a controller 40, such as a microcontroller. The controller 40 may include control circuitry, such as a microprocessor 42 and a memory 48. The control circuitry may include sensory control circuitry that processes the activation field of each sensor 22 to sense a user activation of the corresponding switch by comparing the activation field signal to one or more thresholds in accordance with one or more control routines. It should be appreciated that other analog and/or digital control circuits may be used to process each turn-on field, determine that the user is on, and initiate actions. According to one embodiment, the controller 40 may employ

Available QMatrix acquisition method (QMatrix acquisition method). ATMEL acquisition method

The host C/C + + compiler and the WinAVR debugger simplify development and testing of the eagle eye utility, which allows real-time monitoring of the internal state of software key variables and collection of data logs for post-processing.

The controller 40 provides output signals to one or more devices configured to perform a dedicated action in response to proper activation of the proximity switch. For example, one or more of the devices may include a sunroof 16 having a motor that moves a sunroof panel between open and closed positions and a tilted position, a sunroof visor 18 that moves between open and closed positions, and an illumination device 30 that may be turned on and off. Other devices may be controlled, such as radios that perform on and off functions, volume control, scanning, and other types of devices for performing other dedicated functions. One proximity switch 22 may be dedicated to actuating the glazing closed, another proximity switch 22 may be dedicated to actuating the glazing open, and another proximity switch 22 may be dedicated to actuating the glazing into the tilted position, all of which will cause the motor to move the glazing into the desired position. The sunroof visor 18 may be opened in response to one proximity switch 22 and may be closed in response to the other proximity switch 22.

The controller 40 is further shown as having an analog to digital (A/D) comparator 44 coupled to a microprocessor (μ P) 42. A/D comparator 44 receives the voltage output V from each proximity switch 22_OConverts the analog signal to a digital signal and provides the digital signal to the microprocessor 42. In addition, the controller 40 includes a pulse counter (pulse counter)46 coupled to the microprocessor 42. The pulse counter 46 counts the charge signal pulses applied to each drive electrode of each proximity sensor, performs the counting of the required pulses to charge the capacitor until the voltage output V_OReaches a preset voltage and provides the count to the microprocessor 42. The pulse count is an indication of the change in capacitance of the corresponding capacitive sensor. The controller 40 is further shown in communication with a pulse width modulated drive buffer (pulse width modulated buffer) 15. The controller 40 provides a pulse width modulated signal to the pulse width modulated drive buffer 15 to generate a square wave pulse train V applied to each drive electrode of each proximity sensor/switch 22_I. The controller 40 processes a control routine 100 stored in memory to monitor and make a determination to activate one of the proximity switches.

In fig. 6-13, Sensor charge pulse Count changes, shown as Δ Sensor Count, for a plurality of signal channels associated with a plurality of proximity switches 22, such as the three switches 22 shown in fig. 3, are shown according to various examples. The change in sensor charge pulse count is the difference between the initial reference count value and the corresponding sensor reading when no finger or other object is present in the opening field. In these examples, as the user's finger moves through the switch array, the user's finger enters the turn-on fields 32 associated with each of the three proximity switches, typically one sense turn-on field at a time, with overlap between adjacent turn-on fields 32. Channel 1 is the change in sensor charge pulse count (Δ) associated with a first capacitive sensor 24, channel 2 is the change in sensor charge pulse count associated with an adjacent second capacitive sensor 24, and channel 3 is the change in sensor charge pulse count associated with a third capacitive sensor 24 adjacent the second capacitive sensor. In the disclosed embodiment, the proximity sensor 24 is a capacitive sensor. When a user's finger contacts or comes into close proximity to the sensor 24, the finger changes the capacitance measured on the corresponding sensor 24. The capacitance is parallel to the untouched sensor pad parasitic capacitance (sensor pad parasitic capacitance) and, therefore, the measurement serves as an offset. The capacitance sensed by the user or operator is proportional to the dielectric constant of the user's finger or other body part, the surface exposed to the capacitive keypad, and inversely proportional to the distance of the user's limb from the switch button. According to one embodiment, each sensor is excited with a train of voltage pulses by Pulse Width Modulation (PWM) electronics until the sensor is charged to a set potential. This acquisition method charges the receive electrodes 28 to a known potential. This cycle is repeated until the voltage across the measurement capacitor reaches a preset voltage. Placing the user's finger on the touch surface of the switch 24 introduces an external capacitance that increases the amount of charge delivered per cycle, thereby reducing the total number of cycles required to measure the capacitance to a preset voltage. Because this value is based on the initial reference count minus the sensor reading, the user's finger causes the sensor charge pulse count change to increase.

When a hand, and particularly a finger, is in close proximity to the proximity sensor 22, the proximity switch assembly 20 is able to recognize the user's hand movement to discern whether the user's intent is to turn on the switch 22, to explore a particular switch button while focusing on a high priority task, such as driving, or as a result of a task unrelated to actuation of the proximity switch 22, such as adjusting a rear view mirror. The proximity switch assembly 20 may operate in an exploration or search mode that allows a user to explore a keyboard or button by passing or swiping a finger very close past the switch without causing the switch to open until the user's intent is determined. The proximity switch assembly 20 monitors the amplitude of the signal generated in response to the turn-on field, determines a differential change in the generated signal, and generates a turn-on output when the differential signal exceeds a threshold. Thus, allowing exploration of the access switch assembly 20 so that a user can freely explore the switch interface keypad using his fingers without inadvertent triggering events, the interface response time is fast, opening occurs when the fingers contact the surface panel, preventing or reducing inadvertent opening of the switch.

Referring to FIG. 6, when a user's finger 34 approaches the switch 22 associated with signal channel 1, the finger 34 enters the turn-on field 32 associated with the sensor 24, which causes a perturbation in the capacitance, thereby causing an increase in the sensor count, as shown by signal 50A, which has a typical turn-on motion profile. According to one embodiment, the entry ramp slope method may be used to determine whether the operator intends to press a button or explore the interface based on the slope of the entry ramp of the signal 50A for channel 1, i.e., the slope between the point 52 at which the signal 50A counts through the ACTIVE level (LVL _ ACTIVE) and the point 54 at which the signal 50A counts through the THRESHOLD level (LVL _ THRESHOLD). The slope of the entry ramp is the differential change in the generated signal between

points

52 and 54, which occurs at time t_thAnd t_acIn the time interval in between. Since the counter threshold level-activity level is normally only changed when the presence of a glove is detected, and is otherwise constant, the slope can just be calculated as the time elapsed from the activity level to the threshold level, t_{active2threshold}Which is the time t_thAnd t_acThe difference between them. Direct push switch keypads typically occur in a time interval, referred to as t, in the range of about 40 to 60 milliseconds_directpush. If time t_{active2threshold}Less than or equal to the direct push time t_directpushThen it is determined that switch turn-on has occurred. Otherwise, the switch is determined to be in the exploration mode.

According to another embodiment, the slope of the entry ramp may be calculated as time t at point 52_acAnd time t to reach the peak count value at point 56_pkIs called t_active2peak. Time t_active2peakMay be abbreviated with t_{direct_push_pk}Direct push peak comparison of, according to one embodiment, t_{direct_push_pk}May have a value of 100 milliseconds. If time t_active2peakLess than or equal to t_{direct_push_pk}And judging that the switch is turned on. Otherwise, the switch assembly operates in the sniff mode.

In the example shown in fig. 6, the channel 1 signal is shown to increase as the capacitive disturbance increases, rapidly rising from point 52 to a peak at point 56. The proximity switch assembly 20 determines the entry ramp slope as the time interval t for the signal to rise from the first threshold point 52 to the second threshold at point 54 or the peak threshold at point 56_{active2threshold}Or t_active2peak. The slope or differential change of the generated signal is then used to compare with a typical direct push threshold t_{direct_push}Or t_{direct_push_pk}And comparing to judge the opening of the proximity switch. Specifically, when time t is_active2peakLess than t_{direct_push}Or t_{active2threshold}Less than t_{direct_push}When the judgment switch is turned on, the judgment switch is turned on. Otherwise, the switch assembly remains in the sniff mode.

Referring to fig. 7, one example of a sliding/seeking motion through two switches is the finger passing or sweeping the turn-on fields of two adjacent proximity sensors, shown as signal channel 1 labeled 50A and signal channel 2 labeled 50B. When the user's finger approaches the first switch, the finger enters the turn-on field associated with the first switch sensor, causing a change in the sensor count of signal 50ARises at a slower rate, and thus, the differential change of the determination generation signal is reduced. In this example, the curve of signal channel 1 is not less than or equal to t_{direct_push}Time t of_active2peakUndergoes a change resulting in a search or exploration mode being entered. According to an embodiment, because t_{active2threshold}This is an indication of a slow differential change in the generated signal, so the switch button is not activated to turn on. According to another embodiment, because of time t_active2peakIs not less than or equal to t_{direct_push_pk}Indicating a slow differential change in the generated signal, so turn-on is not initiated. The second signal channel, labeled 50B, is shown as having a maximum signal at transition point 58, and its delta sensor count has a rising change, and the differential change in the signal is similar to signal 50A. Thus, the first and

second channels

50A and 50B reflect the sliding motion of the finger across the two capacitive sensors in the sniff mode, with the result that neither switch is open. Using the time interval t when the capacitance level of the proximity switch reaches the signal peak_{active2threshold}Or t_active2peakA determination may be made to turn on or not turn on the proximity switch.

For a slow direct push action as shown in fig. 8, additional processing may be employed to ensure inadvertent opening. As can be seen in FIG. 8, signal channel 1, labeled signal 50A, is shown at time interval t_{active2threshold}Or t_active2peakAll rise more slowly which will result in entering exploration mode. When such a sliding/exploration condition is detected, time t_{active2threshold}Greater than t_{direct_push}If the channel fails, provided that the first signal channel enters the sniff mode and remains the maximum channel (the channel with the highest intensity) when its capacitance falls below LVL _ KEYUP _ Threshold at point 60, the start switch opens.

Referring to fig. 9, the snap action of a user's finger past the proximity switch assembly is shown with no switch open. In this example, for two channels 1 and 2, represented by

lines

50A and 50B, respectively, a relatively large differential change in the generated signals of channels 1 and 2 is detected. Opening deviceThe off-assembly employs a delay time interval to postpone the on-decision until the second signal channel 50B rises above the transition point 58 at the first signal channel 50A. According to an embodiment, the time delay may be set equal to the time threshold t_{direct_push_pk}. Thus, by employing a delay interval before the switch is determined to be on, the very fast search for proximity to the keyboard prevents inadvertent activation of the switch. Introducing a time delay in the response may make the interface less sensitive and may work better when the operator's finger motion is substantially uniform.

According to one embodiment, the exploration mode may be automatically entered if a previous threshold event that did not result in activation was recently detected. Thus, once inadvertent actuation is detected and rejected, more caution may be exercised for a period of time in the exploration mode.

Another way to allow the operator to enter the exploration mode is to use one or more appropriately marked and/or textured areas or keypads on the switch panel surface associated with a dedicated proximity switch having the function of signaling the proximity switch assembly the operator's blind exploration intent. One or more exploration-reserved keypads may be located in a location that is easily accessible and less likely to generate other signal channel activity. According to another embodiment, a larger exploration reservation keypad around the entire switch interface may be employed, unmarked. When the operator's hand crosses the trim on the overhead console to find a marker and begins a blind search for the proximity switch assembly from that marker, it is likely that such a search keypad will be touched first.

Once the proximity sensor assembly determines that the increase in sensor count change is a result of the switch being open or the exploratory action, the assembly continues to determine whether and how the exploratory action should be terminated or the proximity switch not being open. According to one embodiment, the proximity switch assembly searches for a stable press of the switch button for a minimum amount of time. In a particular embodiment, the predetermined amount of time is equal to or greater than 50 milliseconds, and more preferably about 80 milliseconds. Examples of switch assembly operation using the settling time method are shown in fig. 10-13.

Referring to fig. 10, a search for three proximity switches is shown, corresponding to signal channels 1-3 labeled signals 50A-50C, respectively, with a finger sliding past the first and second switches in search mode and then opening the third switch associated with signal channel 3. When the finger explores the first and second switches associated with channels 1 and 2, it is determined not to turn on since

lines

50A and 50B have no stable signal. The signal on line 50A for channel 1 starts at the maximum signal value until channel 2 on line 50B becomes the maximum value and finally channel 3 becomes the maximum value. Signal channel 3 is shown to have a steady change in sensor count near the peak for a sufficiently long time interval, e.g., 80 milliseconds, that is sufficient to initiate the turn on of the corresponding proximity switch. When the level threshold excitation condition has been met and the peak has been reached, the plateau method is limited to a narrow range of switching levels for at least a time interval t_stableThe switch is then turned on. This allows the operator to explore the various proximity switches and, once it is found, the user's finger remains in a position close to the switch for a stable time interval t_stableThereafter, the desired switch is turned on.

Referring to fig. 11, another embodiment of the level-stabilized approach is shown, where the third signal channel of line 50C has a steady-state sensor count change in signal fall. In this example, the sensor count of the third channel varies beyond a threshold level and has a detection time interval t_stableThus, the third switch is determined to be on.

As shown in fig. 12 and 13, according to another embodiment, the proximity switch assembly may employ a virtual button method that searches for an initial peak of sensor count change in the sniff mode followed by an additional continuous rise with sensor count change to determine switch activation. In FIG. 12, the third signal channel of line 50C rises to an initial peak and then further rises to a sensor count change C_vb. This is equivalent to the user's finger swiping slightly across the switch assembly, touching the desired button, and then pressing on the virtual mechanical switch, such that the user's finger presses on the switch contact surface andand increases the amount of volume that the user's finger is close to the switch. The increased fingertip surface causes an increase in capacitance when the fingertip is squeezed against the keypad surface. The capacitance increase may occur immediately after the peak shown in fig. 12 is detected, or may occur after the sensor count change drops as shown in fig. 13. The proximity switch assembly detects an initial peak followed by a plateau or settling time interval t_stableIs further increased, represented as a capacitance C_vb. The detected steady level generally means a variation of the sensor count value noiseless (sensor count value absent noise), or a small variation of the sensor count value noiseless, which may be preset in the calibration.

It should be appreciated that the shorter time interval t_stableMay result in accidental opening, particularly after reversal of the direction of finger movement, and a longer time interval t_stableA less sensitive interface results.

It should also be appreciated that both the stable value method and the virtual button method may be used. In this case, since the operator can always turn on the button in the virtual button method without waiting for the stabilization push timeout, the stabilization time t can be set_stableRelax to longer, e.g., 1 second.

The proximity switch assembly may further employ robust noise rejection (robust noise rejection) to prevent unwanted actuation by an annoyance. For example, with an overhead console, accidental opening and closing of a glass skylight should be avoided. Excessive noise suppression may eventually reject intentional opening, which should be avoided. One way to suppress noise is to check if multiple adjacent channels report an on event at the same time, and if so, select the signal channel with the highest signal and turn it on, ignoring all other signal channels until the selected signal channel is released.

The proximity switch assembly 20 may include a signature noise rejection method based on two parameters, namely a signature parameter, which is the ratio of the highest intensity channel (max _ channel) to the overall accumulation level (sum _ channel), and a dac parameterNumber, which is the number of channels that is at least proportional to max _ channel. In one embodiment, dac α_dac0.5. The characteristic parameters may be defined by the following equations:

the dac parameter may be defined by the following equation:

according to dac, for an identification to be turned on that is not rejected, the channel must usually be cleared, i.e. the characteristic parameter must be above a predefined threshold. In one embodiment, α_dac＝10.4 and α_dac＝20.67. According to one embodiment, if dac is greater than 2, turn on is denied.

When a decision is made to open or not open the switch in the falling phase of the curve, its peaks peak _ max _ channel and peak _ sum _ channel can be used instead of max _ channel and sum _ channel for calculating the characteristic parameters. The characteristic parameter may be the following equation:

noise suppression causes the possibility of employing a search pattern. The search or exploration mode should be used automatically when a detected opening is rejected due to unclear characteristic parameters. Thus, during blind exploration, the user can touch with all the fingers straight in order to establish the reference frame and thus start the search. This can excite multiple channels simultaneously, thus resulting in poor characterization parameters.

Referring to fig. 14, a state diagram of the proximity switch 20 in one state machine implementation is shown, according to one embodiment. An embodiment of the state machine is shown having five states, including a SW _ NONE state 70, a SW _ ACTIVE state 72, a SW _ THRESHOLD state 74, a SW _ HUNTING state 76, and a SWITCH _ ACTIVATED state 78. The SW _ NONE state 70 is a state in which no sensor activity is detected. The SW _ ACTIVE state is a state in which the sensor detects some activity, but at this point in time is insufficient to cause the switch to open. The SW _ THRESHOLD state is a sensor determined activity high enough to warrant opening, searching/exploration, or accidental action of the switch assembly. The SW _ HUNTING state 76 is entered when the switch assembly determines that the active mode is consistent with the exploration/search interaction. The switched ACTIVATED state 78 is a state in which the SWITCH has been confirmed to be open. In the SWITCH ACTIVATED state 78, the SWITCH buttons will remain on and no further selections can be made until the corresponding SWITCH is released.

The state of the proximity switch assembly 20 changes depending on the detection and processing of the sensing signal. While in the SW _ NONE state 70, the system 20 may advance to the SW _ ACTIVE state 72 when one or more sensors detect certain activity. If activity is detected that is sufficient to warrant a turn-on, search, or contingent action, system 20 may directly enter SW _ THRESHOLD state 74. While in the SW _ THRESHOLD state 74, the system 20 may enter the SW _ HUNTING state 76 when a mode indicating exploration is detected, or the system 20 may directly enter the SWITCH _ ACTIVATED state 78. When the SWITCH is turned on in the SW _ ringing state, the SWITCH turn-on may be detected to change to the SWITCH _ ACTIVATED state 78. If the signal is rejected and unexpected action is detected, system 20 may return to SW _ NONE state 70.

Referring to fig. 15, a primary method 100 of monitoring and determining when to generate a turn-on output using a proximity switch device is shown, according to an embodiment. The method 100 begins at step 102 and then proceeds to step 104 to perform an initial calibration, which may be performed once. At step 106, a calibrated signal channel value is calculated from the raw channel data and the calibration reference value by subtracting the reference value from the raw data. Then, at step 108, the highest count value, referred to as max _ channel, and the sum of all channel sensor readings, referred to as sum _ channel, are calculated from all signal channel sensor readings. In addition, a number of active channels is determined. At step 110, the method 100 calculates the nearest ranges for max _ channel and sum _ channel to subsequently determine if the action is in progress.

Following step 110, the method 100 proceeds to decision step 112 to determine if there is any switch activity. If there is no switching activity, the method 100 proceeds to step 114 to perform an online real-time calibration. Otherwise, the method 116 processes the switch release at step 116. Thus, if the switch has been opened, the method 100 proceeds to a block where all activities are waited and locked until they are released.

After the real-time calibration, the method 100 proceeds to decision step 118 to determine if there is any channel lock indicating a recent opening, and if so, proceeds to step 120 to decrease a channel lock out timer. If channel lock is not detected, the method 100 proceeds to decision step 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 proceeds to step 124 to reset max _ channel, calculate the sum of the ranges, and set the threshold level. Thus, if a new max _ channel is determined, the method resets the nearest signal range and updates the search/exploration parameters, if necessary. If the switch status is less than SW _ ACTIVE, the search/exploration flag is set equal to true (ringing/expansion _ on) and the switch status is set equal to SW _ NONE. If the current max _ channel has not changed, the method 100 proceeds to step 126 to process the max _ channel bare (gloved) finger state. This may include processing logic between different states as shown in the state diagram of FIG. 14.

Following step 126, the method 100 proceeds to decision step 128 to determine if there is any switch activity. If switch activation is not detected, the method 100 proceeds to step 130 to detect the possible presence of a glove on the user's hand. The presence of a glove may be detected from a change in the decrease in the capacitance count value. Method 100 then proceeds to step 132 to update the past history of max _ channel and sum _ channel. Then, before terminating at step 136, the active switch index (index of the active switch), if any, is output to the software hardware module at step 134.

When the switch is turned on, the process switch release routine shown in fig. 16 is turned on. The process switch RELEASE routine 116 begins at step 140 and proceeds to decision step 142 to determine if the active channels are less than LVL _ RELEASE and, if so, ends at step 152. If the active channel is less than LVL _ RELEASE, the routine 116 proceeds to decision step 144 to determine if LVL _ DELTA _ THRESHOLD (level _ Delta _ Threshold) is greater than 0, if not, and proceeds to step 146 to increase the THRESHOLD level if the signal is stronger. This can be achieved by lowering the LVL _ DELTA _ THRESHOLD. Step 146 also sets a threshold, a release level, and an activity level. Routine 116 then proceeds to step 148 to reset the channel max and sum history timers for the long term stable signal search/discovery parameters. Before terminating at step 152, the switch state is set equal to SW _ NONE at step 150. To exit the process switch RELEASE module, the signal of the active channel must fall below LVL _ RELEASE, which is an adaptive threshold that will change when glove intervention is detected. When the toggle button is released, all internal parameters are reset and the lock timer is started to prevent further starting until the end of a certain waiting time, e.g. 100 ms. Further, the threshold level is adjusted according to the presence or absence of gloves.

Referring to FIG. 17, a routine 200 is shown for determining a change in state from SW _ NONE to SW _ ACTIVE according to one embodiment. The routine 200 begins at step 202 to process the SW _ NONE state and then proceeds to decision step 204 to determine if max _ channel is greater than LVL _ ACTIVE. If max _ channel is greater than LVL _ ACTIVE, the proximity switch assembly changes state, changes from SW _ NONE state to SW _ ACTIVE state, and ends at step 210. If max _ channel is not greater than LVL _ ACTIVE, the routine 200 checks to reset the search flag in step 208 before terminating at step 210. Thus, when max _ channel triggers the above-mentioned LVL _ ACTIVE, the state changes from SW _ NONE to SW _ ACTIVE. If the channel remains below this level, after a certain waiting time, the search flag is reset to no search if the search flag is set, which is one of the methods of leaving the search mode.

Referring to FIG. 18, a method 220 of processing a state transition from the SW _ ACTIVE state to the SW _ THRESHOLD state or the SW _ NONE state is shown, according to another embodiment. The method 220 begins at step 222 and then proceeds to decision step 224. If max _ channel is not greater than LVL _ THRESHOLD, the method 220 proceeds to step 226 to determine if max _ channel is less than LVL _ ACTIVE and, if so, to step 228 to change the switch state to SW _ NONE. Thus, when the max _ channel signal falls below LVL _ ACTIVE, the state of the state machine moves from the SW _ ACTIVE state to the SW _ NONE state. A delta value may also be subtracted from LVL ACTIVE to introduce some hysteresis. If max _ channel is greater than LVL _ THRESHOLD, routine 220 proceeds to decision step 230 to determine if the most recent THRESHOLD event or glove has been detected, and if so, sets the search for the flag equal to true (true) at step 232. Before terminating at step 236, the method 220 transitions the state to the SW _ THRESHOLD state at step 234. Therefore, if max _ channel causes LVL _ THRESHOLD as described above, the state changes to SW _ THRESHOLD state. If a glove is detected, or a previous threshold event that did not cause opening has been recently detected, the search/exploration mode may be automatically entered.

Referring to FIG. 19, a method 240 of determining switch turn-on from the SW _ THRESHOLD state is shown, according to one embodiment. Method 240 begins at step 242 with processing the SW _ THRESHOLD state and proceeds to decision block 244 to determine whether the signal is stable or whether the signal channel is at a peak, and if not, terminates at step 256. If the signal is stable or the signal channel is at a peak, then the method 240 proceeds to decision step 246 to determine if the search or exploration mode is on and, if so, jumps to step 250. If the seek or exploration mode is not on, the method 240 proceeds to decision step 248 to determine if the signal channel is clear and fast on is greater than a threshold, and if so, the switch _ active is set equal to maximum _ channel in step 250. The method 240 proceeds to decision block 252 to determine if there is switching activity and, if so, terminates at step 256. If there is no switching activity, the method 240 proceeds to step 254, where the search variable SWITCH _ STATUS is initially set equal to SWITCH _ HUNTING (SW _ EXPLORATION/HUNTING) and PEAK _ MAX _ BASE (Peak _ Max _ cardinal) is initially set equal to MAX _ CHANNELS before terminating at step 256.

In the SW _ THRESHOLD state, no determination is made until a peak value of MAX _ CHANNEL is detected. The condition for detecting a peak is a reversal of the signal direction, or MAX _ CHANNEL and SUM _ CHANNEL remain stable (within a range) for at least a certain time interval, e.g. 60 milliseconds. Once a peak is detected, the search flag is checked. If the search mode is off, the entry ramp slope method is applied. If the time from SW _ ACTIVE to SW _ THRESHOLD is less than a THRESHOLD, e.g., 16 milliseconds, and the characteristics of the noise suppression method indicate that it is a valid ON event, the state changes to SWITCH _ ACTIVE and the PROCESS moves to the PROCESS _ SWITCH _ RELEASE module, otherwise the search flag is set equal to true. If a delay-on method is adopted instead of immediately turning on the switch, the state transitions to SW _ delay _ activity, in which a delay is enforced, and at the end of the delay, the button is turned on if the current MAX _ CHANNEL index has not changed.

Referring to FIG. 20, a virtual button method implementing the SW _ HUNTING state is shown, according to one embodiment. The method 260 begins at step 262 to process the SW _ HUNTING state and proceeds to decision step 264 to determine if MAX _ CHANNEL has fallen below LVL _ KEYUP _ THRESHOLD, and if so, sets MAX _ PEAK _ BASE equal to MIN (MAX _ PEAK _ BASE, MAX _ CHANNEL) at step 272. If MAX _ CHANNEL has fallen below LVL _ KEYUP _ THRESHOLD, the method 260 proceeds to step 266 to check if the event will cause the button to turn on using a first CHANNEL cause search. Depending on whether it is decided to cross the first and only channel and the signal is clear. If so, before terminating at step 282, the method 260 sets switch _ active equal to maximum _ channel at step 270. If the first and unique channel is not traversed and the signal is not clear, the method 260 proceeds to step 268 to stop and determine accidental actuation and sets SWITCH _ STATUS equal to SW _ NONE before terminating at step 282.

Following step 272, the method 260 proceeds to decision step 274 to determine whether the channel is selected (clicked). This depends on whether MAX _ CHANNEL is greater than MAX _ PEAK _ BASE plus a delta value (delta). If the channel is selected, the method 260 proceeds to decision step 276 to determine if the signal is stable and clear and if so, sets the switch activity state to the maximum channel at step 280 before terminating at step 282. If the channel is not selected, the method 260 proceeds to decision step 278 to check if the signal is long, stable, and clear, and if so, to step 280 to set switch _ active equal to maximum _ channel before terminating at step 282.

According to another embodiment, the proximity switch assembly 20 may include a virtual button pattern. Referring to fig. 21-27, a proximity switch assembly having a virtual button mode and a method of actuating a proximity switch using the virtual button mode are shown therein according to the present embodiment. The proximity switch assembly may include one or more proximity switches, each of which provides a sensing turn-on field, and control circuitry for controlling the turn-on field of each proximity switch to sense turn-on. The control circuit monitors the signal indicative of the turn-on field, determines a first stable amplitude of the signal for a period of time, determines a subsequent second stable amplitude of the signal for the period of time, and generates a turn-on output when the second stable signal exceeds the first stable signal by a known amount. The method may be employed with a proximity switch assembly and include the steps of generating an activation field associated with each of one or more proximity sensors, and monitoring a signal indicative of each associated activation field. The method further includes the steps of determining a first amplitude when the signal is stable for a minimum time, and determining a second amplitude when the signal is stable for the minimum time. The method further includes the step of generating an on output when the second amplitude exceeds the first amplitude by a known amount. Thus, the virtual button mode provides a proximity switch that prevents or reduces inadvertent or false activation that may be caused by exploring multiple proximity switch buttons and redirecting fingers or by gloved fingers.

In FIG. 21, the exploration and activation of proximity switches is shown for entry when a user's finger slides over the corresponding switchExplore mode and proceed to one of the signal channels labeled signal 50 when the switch is turned on in virtual button mode. It should be appreciated that a user's finger may explore a plurality of capacitive switches as shown in fig. 10-12, wherein the signals associated with each respective signal channel are generated as the finger crosses the turn-on field of each channel. Multiple signal channels may be processed simultaneously and the largest signal channel may be processed to determine the activation of the corresponding proximity switch. In the example provided in the signal diagrams of fig. 21-25, a single signal channel associated with one switch is shown, however, multiple signal channels may be processed. The signal 50 associated with one of the signal channels shown in fig. 21 is shown rising to a threshold activity level 320 at point 300, at which point the signal enters an exploration mode. The signal 50 thereafter continues to rise and reaches the first amplitude at which point the signal stabilizes for a minimum period of time, as indicated by the Tstable displayed at point 302. At point 302, signal 50 enters the virtual button mode and creates a first base value Cbase, which is the incremental signal count at point 302. At this point, the virtual button mode is multiplied by a constant K according to the base value Cbase_vbAn incremental opening threshold is created. The turn-on threshold for determining turn-on may be passed through (1+ K)_vb) X Cbase where K is_vbIs a constant greater than zero. The virtual button mode continues to monitor the signal 50 to determine when it reaches a second stable amplitude for a minimum time Tstable, which occurs at point 304. At this point 304, the virtual button mode compares the second stable amplitude to the first stable amplitude and determines whether the second amplitude exceeds the first amplitude by K_vbKnown amount of x Cbase. If the second amplitude exceeds the first amplitude by a known amount, an on output is generated for the proximity switch.

According to this embodiment, the amplitude of the steady signal must be maintained through the signal channel for at least a minimum period Tstable before entering the virtual button mode or determining the turning on of the switch. The sensor value when it enters the virtual button mode is recorded as Cbase. The method monitors when the amplitude of a subsequent steady signal is again achieved before the timeout period. If the amplitude of the steady signal is greater than the expired timeout periodThe delta count value of the desired percentage of the previously recorded Cbase (say 12.5% of the previously recorded Cbase) is again achieved and the turn on is triggered. According to one embodiment, the percentage increment signal count increase of at least 10% is by K_vbX Cbase.

According to one embodiment, the multiplier K_vbIs a factor of at least 0.1, or at least 10% of the value of Cbase. According to another embodiment, the multiplier K_vbSet to about 0.125, which corresponds to 12.5%. According to an embodiment, the stabilization period Tstable may be set to a time of at least 50 milliseconds. According to another embodiment, the stabilization period Tstable may be set in the range of 50 to 100 milliseconds. The stable amplitude may be determined by the signal amplitude being substantially stable, according to an embodiment within a range of twice the magnitude of the estimated signal noise, or according to another embodiment within 2.5 to 5.0% of the signal level, or according to yet another embodiment a combination of twice the estimated signal noise plus a signal level of 2.5 to 5.0%.

Referring to fig. 22, a signal 50 for a signal channel associated with a proximity switch is illustrated that enters an exploration mode at point 300 and proceeds to reach a stable first amplitude when the amplitude of the stable signal exists for a minimum time Tstable at point 302 (where the virtual button mode is entered). At this point, the Cbase value is determined. Thereafter, the signal 50 is shown falling and rising again to a second amplitude when the signal stabilizes for a minimum time Tstable at point 306. In this case, however, the second amplitude at point 306 does not exceed the base value of the signal at point 302 Cbase by K_vbA known amount of x Cbase, and therefore will not generate an on output for the switch.

Referring to fig. 23, a signal 50 associated with a signal channel is illustrated entering an exploration mode at point 300 and continuing to reach a first amplitude stabilization period Tstable at point 302, where a virtual button mode is entered and Cbase is determined. Thereafter, the signal 50 continues to rise to a second amplitude, which stabilizes at a point 308 for a minimum time Tstable. However, at point 308, the second amplitude does not exceed the base value Cbase of the signal created at the first amplitude at point 302 by K_vbKnown amount of x Cbase, so close toThe switch assembly does not trigger the switch output. However, a new updated base value for Cbase at point 308 is generated and used to determine the known quantity to compare to the next stable amplitude. The signal 50 is shown to fall and then rise to a third amplitude, which stabilizes at a point 310 for a minimum time Tstable. The third amplitude exceeds the second amplitude by more than a known amount K_vbX Cbase so that an on output for the switch is generated.

Referring to fig. 24, another example of a signal 50 is illustrated that enters the exploration mode at point 300 and continues to rise at point 302 for a first amplitude stabilization period Tstable, where the virtual button mode is entered and Cbase is determined. Thereafter, the signal 50 shows a drop to a second amplitude, which stabilizes at a point 312 for a minimum time Tstable. At point 312, the second amplitude does not exceed the first amplitude by K_vbX Cbase, so that a trigger for the signal is not generated. However, an updated base value Cbase may be generated at point 312. Thereafter, the signal 50 continues to rise to a third amplitude, which stabilizes at a point 310 for a minimum time Tstable. The third amplitude exceeds the second amplitude by a known amount K_vbX Cbase so that an on output for the switch is generated.

Referring to fig. 25, another example of a signal 50 for a signal channel is shown entering an exploration mode at point 300 and continuing to reach a first amplitude for a minimum stabilization period Tstable at point 302 and thus entering a virtual button mode and determining Cbase. Next, the signal 50 continues to rise to a second amplitude, which stabilizes for a time Ttable at point 308. The second amplitude does not exceed the first amplitude by a known amount so that triggering of the switch is not generated at this point. Thereafter, the signal 50 shows a drop to point 314 and in so doing, the reset timer times out because the last stable amplitude was received as indicated by time Treset. When the reset timer times out, at point 314, the virtual button mode is exited and upon exiting the virtual button mode, the exploration mode is entered. When this occurs, the previously determined Cbase is no longer valid. Thereafter, the signal 50 is shown to rise to a third amplitude, which stabilizes for a minimum time at point 316. At this point, the third amplitude creates an updated Cbase that is used to determine the future opening of the switch. Thereafter, signal 50 further shows a drop below threshold activity value 320, in which case virtual button mode is exited without any actuation.

A method of actuating a proximity switch using a virtual button mode using a proximity switch assembly is illustrated in fig. 26 and 27. Referring to fig. 26, the method 400 begins at step 402 and continues at step 404 to obtain all signal channels associated with all proximity switches. The method 400 continues to decision block 406 to determine whether the state is set in the ACTIVE state and, if so, checks for release of the switch at step 414 before ending at step 416. If the state is not set in the ACTIVE state, the method 400 proceeds to step 408 to find the largest Channel (CHT). Next, once the largest channel has been found, the routine 400 proceeds to step 410 to process the largest Channel (CHT) virtual button method before ending at step 416. The procedural maximum channel virtual button method 410 is illustrated in fig. 27 and described below. It should be appreciated that the method 400 may include an optional step 412 that is also used to process the maximum channel signal using a tapping method to detect a user tap on the proximity switch to generate an on output.

The process maximum channel virtual button method 410 shown in fig. 27 begins at step 420 and proceeds to step 422 to input a maximum channel signal. Thus, the maximum signal channel associated with one of the proximity switches is processed to determine the virtual button mode state and the activation of the switch, and at decision step 424, the method 410 determines whether the switch is set to the virtual button mode state, and if so, proceeds to decision step 426 to determine whether the signal channel value is less than the activity threshold. If the signal channel is less than the activity threshold, the method 410 proceeds to step 428 to set the status equal to NONE and returns to the beginning. If the signal channel is not less than the activity threshold, the method 410 proceeds to decision step 430 to determine if the signal has a stable first amplitude for a period of time that is greater than the stable period Tstable. If the stable signal channel at the first amplitude is stable for a period of time greater than Tstable, the method 410 proceeds to decision step 432 to determine if the signal channel is not stable for a period of time exceeding the reset time Treset, and, if not, returns to step 422. If the signal channel has not settled for a period of time exceeding the reset time Treset, the method continues to set the state equal to the exploration/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 stability period Tstable, the method 410 proceeds to decision step 436 to determine whether the signal ch (t) is greater than Cbase for a pass K_vb×C_baseA defined known quantity, and if so, set the switch state to on to generate an on output before ending at step 460. If the signal does not exceed Cbase by K_vb×C_baseThen the method 410 proceeds to set a new Cbase value at the current stable signal amplitude at step 440 before ending at step 460.

Returning to decision step 424, if the switch state is not set to the virtual button mode, the method 410 proceeds to decision step 442 to determine if the state is set to the exploring state, and if so, to decision step 444 to determine if the signal is greater than the activity threshold, and if not, to set the state equal to the NONE state and end at step 460. If the signal is greater than the activity threshold, the method 410 proceeds to decision step 448 to determine if the signal is stable at amplitude for more than a minimum time Ttable, and if not, ends at step 460. If the signal has settled at amplitude for a time exceeding the minimum time Ttable, the method 410 proceeds to step 450 to set the state of the switch to the state of the virtual button and creates a new Cbase value for the signal channel at step 450 before ending at step 460.

Returning to decision step 442, if the state of the switch is not set to the sniff/search state, the method 410 proceeds to decision step 452 to determine if the signal is greater than the activity threshold, and if not, ends at step 460. If the signal is greater than the activity threshold, the method 410 proceeds to decision step 454 to set the state to the exploration/search state before ending at step 460.

Accordingly, the proximity switch assembly with the virtual button method 410 advantageously provides for enhanced virtual button switch actuation detection and enhanced rejection of inadvertent actuations. The method 410 may advantageously detect the opening of the switch while rejecting inadvertent openings that may be detected when the finger exploration switch assembly and reverses direction or where the user's fingers are wearing gloves. The enhanced on detection advantageously provides an enhanced proximity switch assembly.

Thus, the determination routine advantageously determines the activation of the proximity switch. The routine advantageously allows a user to explore a proximity switch keypad, which is particularly useful in automotive applications where driver distraction can be avoided.

According to yet another embodiment, the proximity switch assembly 20 may include a flexible material covering the proximity sensor and control circuitry, wherein the control circuitry may turn on the proximity switch based on a signal generated by the sensor when a user's finger presses the flexible material as compared to a threshold value. In this embodiment, the proximity switch assembly 20 may operate in a virtual button mode and may provide enhanced signal detection by employing a flexible material that deforms to allow a user's finger to move proximate to the proximity sensor. Furthermore, a void space in the form of an air pocket may be provided between the flexible material and the proximity sensor, and a raised or elevated surface may further be provided in the flexible material.

Referring to fig. 28A-31, a proximity switch assembly 20 employing a flexible material and operating in a virtual button mode and a method of actuating a proximity switch using the flexible material in the virtual button mode are shown therein according to the present embodiment. The proximity switch assembly 22 may include a proximity sensor, such as a capacitive sensor, that generates an on field. It should be appreciated that multiple proximity sensors 24, each generating an on field, may be employed. According to one embodiment, the proximity sensor 24 is shown as being provided on a surface of a rigid carrier, such as a polymeric overhead console 12. Each proximity sensor 24 may be formed by printing conductive ink onto the surface of the polymeric overhead console 12. According to other embodiments, the proximity sensor 24 may be formed in other ways, such as by assembling a pre-formed conductive circuit wiring onto the carrier.

The flexible material 500 is shown covering the carrier 12 and is intended to provide a touch surface for the user's finger 34 to interact with the proximity sensor 24 to open the switch 22. According to one embodiment, the flexible material 500 is shown forming a cover layer, which may be comprised of an elastomeric material including rubber. The flexible material 500 is flexible relative to the generally rigid base carrier 12. The flexible material 500 covers the proximity sensor 24 and is deformable when pressure is applied by the user's finger 34 so that the finger 34 compresses the flexible material 500 and moves inwardly toward the proximity sensor 24 as shown in fig. 28C. According to an embodiment, the flexible material 500 may have a layer thickness in the range of 0.1 to 10mm, and more preferably in the range of 1.0 to 2.0 mm.

The proximity switch assembly 20 employs control circuitry for monitoring the activation field associated with each sensor 24 and determining activation of the proximity switch based on a signal generated by the proximity sensor 24 when the user's finger 34 presses against the flexible material 50 as compared to a threshold value. The control circuit may determine a stable amplitude of the signal generated by the proximity sensor 24 for a predetermined time and may generate a switch on output when the stable output exceeds a threshold. According to an embodiment, a control circuit may determine a first stable amplitude of a signal over a period of time, may determine a subsequent second stable amplitude of the signal over the period of time, and may generate an on output for a proximity switch associated with the signal when the second stable signal exceeds the first stable signal by a known amount.

Referring to fig. 28A-28D, the proximity switch assembly 20 is illustrated in accordance with one embodiment using a flexible material 500 covering one or more proximity sensors 24. As shown in fig. 28A, the user's finger 34 shown in the first position contacts the surface of the flexible material 500 at a location proximate to but laterally displaced from the proximity sensor 24. In fig. 28B, the user's finger 34 is shown being moved by sliding laterally to a second position aligned with the proximity sensor 24 without applying pressure to the flexible material 500. This may occur when the user is exploring the proximity sensor assembly 20 in the exploration/search mode without intending to open the switch 22. In fig. 28C, the user's finger 34 is shown applying pressure to the proximity sensor 24 in order to press the flexible material 500 to move the user's finger 34 to a third position proximate to the proximity sensor 24. The user's finger 34 may thus press onto the flexible material 500 and deform the flexible material 500 to move closer to the proximity sensor 24, and may further collapse and thus flatten the finger 34 against the carrier 12 to provide an enhanced surface area or volume of the finger in close proximity to the sensor 24, with the sensor 24 providing greater interaction with the associated turn-on field, and thus, a greater signal.

The sequence of events shown in fig. 28A-28C is further illustrated in the signal response shown in fig. 28D. The signal 506 generated by the proximity sensor 24 is shown rising to a first level 506A indicating that the user's finger 34 is in contact with the proximity switch assembly 20 at a first position laterally away from the proximity sensor 24 as shown in fig. 28. The signal 506 then rises to a level 506B indicating that the user's finger 34, shown in the second position aligned with the proximity sensor 24, has no pressure applied as shown in fig. 28B. Thereafter, the signal 506 then rises to a third elevated level 506C, which instructs the user's finger 34 to apply pressure in a third position to press the flexible material 500 as shown in fig. 28C. Thus, the signal 506 is very large when the user's finger 34 is pressed into the flexible material 500, which allows for virtual button detection.

When the user's finger presses the flexible material 500, the control circuitry monitors the turn-on field and determines to turn on the proximity switch based on the signal 506 when the user's finger presses the flexible material 500 as compared to a threshold value. The processing circuitry may include a controller 400, as shown in fig. 5, for executing a control routine that may include the routine 520 described and illustrated herein in connection with fig. 31. Thus, the processing circuitry may use the virtual button approach described above to detect the exploration mode and the activation of the virtual buttons of the one or more proximity switches.

According to another embodiment, the proximity switch assembly 20 may be further configured with a flexible material 500 having a raised or bumped contact surface portion 502, wherein the contact surface portion 502 is aligned with each proximity sensor 24 and a void space or air gap 504, the void space or air gap 504 being disposed between the raised portion 502 and the proximity sensor 24, as shown in fig. 29A-29C. In this embodiment, the air gap 504 formed between the flexible material 504 and each proximity sensor 24 provides an enhanced pressing distance during switch opening, which may also be used for a tactile feel to the user. According to an embodiment, the air gap 504 may have a height distance of less than 5.0mm, more preferably in the range of 1.0 to 2.0 mm. The raised portion 502 of the flexible material 500 keeps the user's finger 34 farther from the proximity sensor 24 in an unpressed state. As shown in fig. 29A, the user's finger 34 contacts the proximity switch assembly 20 at a location that is close to but laterally distant from the proximity sensor 24 in the first position. Next, at fig. 29B, the user's finger 34 is moved to a second position, wherein the second position is aligned with the proximity sensor 24 on the raised portion 502 of the flexible material 500. In this position, the user's finger 34 may explore the proximity switch 22 in the exploration/search mode without intending to turn on the switch. In fig. 29C, the user's finger 34 is shown in a third position pressing the flexible material 500 on top of the raised portion 502 to move the finger 34 to a fully depressed state, which compresses the flexible material 500 and the air gap 504 to allow the user's finger to be in a closer position relative to the proximity sensor 24. When this occurs, the control circuit detects the user's intent to open the switch 22 and generates an open output signal.

Referring to fig. 29D, the signal 506 generated by the proximity sensor 24 in response to the turning on of the turn-on field is displayed relative to the user's finger actuation shown in fig. 29A-29C. The signal 506 is shown to rise to a first level 506A indicating that the user's finger 34 in the first position contacts the proximity switch assembly 20 laterally away from the sensor 24 as shown in fig. 29A. The signal 506 remains at a first level 506A as shown by level 506B while the user's finger is raised to a second position on the raised portion 502 aligned with the proximity sensor top 24 without pressing the flexible material 500, as shown in fig. 29B. Raised portion 502 thus allows signal 506 to remain a low signal when the user's finger is in the sniff mode and is not intended to open switch 22. The signal 506 is shown increasing to a further elevated level 506C that indicates that the user's finger 34 is pressing the flexible material in the third position to open the switch by compressing the raised portion 502 and the air gap 504 as shown in fig. 29C. When this occurs, the control circuit processes signal 506 to detect the opening of switch 22 and may further detect the search/seek mode as described above.

Referring to FIG. 30, a state diagram of a proximity switch assembly in another state machine implementation is shown, utilizing flexible material and a virtual button mode, according to an embodiment. The state machine implementation is shown with four states including a wait state 510, a search state 512, a virtual button state 514, and a button press state 516. The wait state 510 is entered when the signal is less than a threshold indicating that no sensor turn-on is detected. The search state 512 is entered when the signal is greater than a threshold value indicating activity determined to match the exploration/search interaction. When the signal is stable, the virtual button state 514 is entered. The button press state 516 indicates a strong pressure on the switch to compress the flexible material once in the virtual button state. When the signal reaches a certain threshold, the exploration/search mode 512 is entered. When the signal is stable and greater than the base level, virtual button mode 514 is entered. If the signal is stable and greater than the base level plus a delta dome value, the button push mode 516 is entered. It should be appreciated that the base level may be updated as described above.

Referring to fig. 31, a routine 520 for controlling the proximity switch assembly and method of using the flexible material to open as described above in connection with fig. 28A-30 is shown and described herein. According to one embodiment, routine 520 may be stored in memory 48 and executed by controller 40. The routine 520 begins at step 522 to process the bulky or maximum signal channel associated with one of the proximity switches. At step 524, the maximum signal channel is input to the controller. Next, at decision step 526, routine 520 determines whether the current state is set to a wait state and, if so, proceeds to decision step 528 to determine whether the maximum signal channel is greater than a threshold. If the maximum signal channel is not greater than the threshold, routine 520 ends at step 530. If the maximum signal channel is greater than the threshold, routine 520 proceeds to set the state to the search state at step 532 before ending at step 530.

Returning to decision step 526, if the state is set to the wait state, routine 520 proceeds to decision step 534 to determine if the state is set to the search state, and if so, to decision step 536 to determine if the maximum signal channel is less than the threshold. If the maximum signal channel is less than the threshold, routine 520 proceeds to step 538 to set the state to a wait state and then ends at step 530. If the maximum signal channel is not less than the threshold 536, the routine 520 proceeds to decision step 540 to determine if all signal channels are stable, and if not, ends at step 530. If all signal channels are stable, routine 520 proceeds to step 542 to set the state equal to the virtual button state, and thereafter sets the channel floor to the maximum signal channel at step 544 before ending at step 530.

Returning to decision step 534, if the state is not set equal to the search state, then routine 520 proceeds to decision step 546 to determine if the state is in the virtual button state, and if not, to step 548 to set the state to the button push state. Thereafter, routine 520 proceeds to decision step 550 to determine if the maximum signal channel is less than the threshold, and if not, ends at step 530. If the maximum channel (MaxCH) is less than the threshold, routine 520 sets the state equal to the wait state at step 552 and then releases the turn-on at step 554 before ending at step 530.

Returning to decision step 546, if the state is set equal to the virtual button state, routine 520 proceeds to decision step 556 to determine if the maximum signal channel is less than the threshold, and if so, sets the state equal to the wait state at step 558 before ending at step 530. If the maximum signal channel is not less than the threshold, routine 520 proceeds to decision step 560 to determine if the virtual button timer is greater than the timeout, and if so, sets the state to the search state at step 562 before ending at step 530. According to one embodiment, the virtual button timer may be set to a range of one to three seconds. If the virtual button timer has not exceeded the timeout, routine 520 proceeds to decision 564 to determine if all signal channels are stable and, if not, ends at step 530. If all of the signal channels are determined to be stable, routine 520 proceeds to decision step 566 to determine if the rubber dome is depressed, which may be determined by the maximum signal channel being greater than the signal channel floor summed with the single incremental ceiling. If the rubber dome is depressed, the process 520 proceeds to decision step 568 to set the state equal to the button push state and thereafter generates the opening of the largest signal channel at step 570 before ending at step 530. If the rubber dome is not pressed, the routine 520 proceeds to step 572 to determine that the finger is still sliding and updates the base signal ChBase to the maximum signal channel at step 572 before ending at step 530.

Accordingly, the proximity switch assembly 20 having the flexible material 500 and the virtual button pattern advantageously provides enhanced virtual button switch activation detection to enhance rejection of inadvertent activation. The method 520 may advantageously detect the opening of a switch while rejecting inadvertent opening of the switch that may be detected when a finger is exploring the switch assembly. The enhanced activation detection advantageously provides an enhanced proximity switch assembly that may be particularly advantageous or useful in automotive applications where driver distraction may be avoided.

According to one embodiment, the proximity switch assembly 20 may include a rigid carrier having a first upper surface and a second bottom surface, a proximity sensor disposed on the carrier, a flexible material disposed on the upper surface of the carrier, and a recess formed in the upper surface of the carrier in an area between the flexible material and the proximity sensor. The size of the recess is typically larger than the proximity sensor, such that the recess has a longer length and width compared to the proximity sensor. The recess allows the formation of an air gap between the flexible material and the proximity sensor.

Referring to fig. 32-34D, a proximity switch assembly 20 is illustrated according to one embodiment that employs a flexible material 500 covering a rigid carrier 12 and a recess 600 formed in an upper surface of the carrier 12. The proximity switch assembly 20 includes a rigid carrier 12, the rigid carrier 12 being shown generally as a flat plate having first and second surfaces, the first and second surfaces being shown as upper and bottom surfaces. First and second proximity sensors 24, such as capacitive sensors, are shown disposed on the bottom surface of the carrier 12, each sensor generating an activation field for a corresponding proximity switch 22. It will be appreciated that one or more proximity sensors 24 may be included, each sensor generating an on field. According to one embodiment, the proximity sensor 24 is shown disposed on a bottom surface of the rigid carrier 12, such as the polymer overhead console 12. Each proximity sensor 24 may be formed by printing conductive ink onto the bottom surface of the rigid carrier 12. According to other embodiments, the proximity sensor 24 may additionally be formed, for example, by mounting a prefabricated conductive circuit wiring to the carrier 12.

A flexible material 500 is shown covering the carrier 12 and is intended to provide a touch surface for the user's finger 34 to interact with the one or more proximity sensors 24 to activate the one or more proximity switches 22. According to one embodiment, the flexible material 500 may be formed as a covering layer that may be made of an elastic material, including rubber. The flexible material 500 is flexible relative to the generally rigid base carrier 12. The flexible material 500 covers the proximity sensor 24 and is deformable when pressure is applied by the user's finger so that the finger 34 depresses the flexible material 500 and moves toward the proximity sensor 24. The flexible material 500 may have a thickness as described above with respect to other embodiments, for example in the range of 0.1 to 10 millimeters, and more preferably in the range of 1.0 to 2.0 millimeters.

The proximity switch assembly 20 also includes a recess 600 in the upper surface of the rigid carrier 12 in the area between the flexible material 500 and each proximity sensor 24. Individual recesses 600 may be formed in the upper surface of the carrier 12, each generally proximate to one of the proximity sensors 24. The recess 600 has a length and width dimension greater than the proximity sensor 24. The relative size of the recess 600 with respect to the proximity sensor 24 is illustrated in fig. 33. The recess 600 has a first length L_DIn contrast, the proximity sensor 24 has a second length L_SWherein according to one embodiment the first length L_DIs greater than the second length L_SAt least 5 mm. According to a more specific embodiment, the first length L_DExceeds the second length L_SA distance in the range of 5 to 10 mm. The recess 600 also has a width W that is greater than the width Ws of the proximity sensor 24_D. According to one embodiment, the width W_DCan exceed the width W_SAn amount of at least 5 mm and more particularly a distance in the range of 5 to 10 mm. According to one embodiment, the recess 600 may have a thickness in the range of 0.5 to 2.0 millimeters.

Although the proximity switch assembly 20 is shown and described herein as having the respective proximity sensor 24 and recess 600 formed in a rectangular shape, it should be understood that the sensor 24 and recess 600 may comprise other shapes and sizes, such as a circular shape or other shapes. In doing so, the recess 600 has a depth, and also has a dimension size that is greater than the length and/or width dimension of the proximity sensor 24 proximate thereto. For circular proximity sensors 24 and recesses 600, the dimension may be a length measurement of the diameter of the circular shape of each sensor 24 and recess 600, wherein the dimension of the recess 600 is greater than the dimension of the proximity sensor 24 by an amount of at least 5 millimeters, more particularly in the range of 5 to 10 millimeters, according to one embodiment.

According to one embodiment, the recess 600 formed in the rigid carrier 12 provides a space for an air gap to be formed between the bottom surface of the recess 600 of the carrier 12 and the covering flexible material 500. The air gap formed within the recess 600 provides space for the user's finger to press the flexible material 500 inward and into close proximity to the proximity sensor 24. While air gaps are shown and described herein as filling void spaces within the recess 600, it should be appreciated that another material, such as a liquid or other gas, may be disposed therein. It should also be appreciated that a soft flexible material may be disposed within the recess 600, the material being substantially less rigid than the rigid carrier 12.

The proximity switch assembly 20 may also employ control circuitry for monitoring the activation field associated with each proximity sensor 24 and determining the activation of the corresponding proximity switch 22 based on a signal generated by the proximity sensor 24 with respect to a threshold value when the user's finger 34 presses the flexible material 500 into the recess 600. As the user's finger moves closer to the proximity sensor 24, the amplitude of the signal generally increases. The control circuit may operate as described above with respect to the embodiment shown in fig. 28A-31.

Referring to fig. 34A-34D, a proximity switch assembly 20 is illustrated with a flexible material 500 covering a recess 600 on each proximity sensor 24, according to a first embodiment. As shown in fig. 34A, the user's finger 34 is shown in a first position contacting the upper surface of the flexible material 500 at a location proximate to but laterally displaced from the proximity sensor 24 and the recess 600. In fig. 34B, the user's finger 34 is shown moving by lateral sliding to a second position above the center alignment of the proximity sensor 24 and the recess 600 without applying force or pressure to the flexible material 500. This may occur when the user is exploring the proximity sensor assembly 20 in the exploration/search mode without intending to turn on the proximity switch 22. In fig. 34C, the user's finger 34 is shown applying a force toward the proximity sensor 24 so as to press the flexible material 500 to move the user's finger 34 to a third position proximate the proximity sensor 24 so as to depress the flexible material 500 and disrupt the air gap disposed within the recess 600, and may further collapse and thereby flatten the finger 34 against the carrier 12 within the bottom of the recess 600 to provide an increased surface area or volume of the finger in close proximity to the sensor 24, which provides for greater interaction of the associated opening fields, and therefore, a greater signal.

The sequence of events shown in fig. 34A-34C is further illustrated in the signal 606 response shown in fig. 34D. The signal 606 generated by the proximity switch 24 is shown rising to a first level 606A indicating that the user's finger 34, seen in fig. 34A, is in contact with the proximity switch assembly 20 at a first location laterally away from the proximity sensor 24. The signal 606 maintains the signal amplitude at a level 606B indicating that the user's finger 34 shown in fig. 34B is at the second position aligned with the proximity sensor 24 and the recess 600 without applying a force. Thereafter, the signal 606 then rises to a third elevated level 606C, which indicates that the user's finger shown in fig. 34C is applying a force in a third location to press the flexible material 500 into the recess 600. Thus, when the user's finger 34 presses the flexible material 500 into the recess 600, the signal 606 is greater, which allows for improved switch detection. The control circuit may then monitor the turn-on field and the signal 606 and determine the turn-on of the proximity switch 22 based on the signal 606 as described herein.

According to another embodiment, the proximity switch assembly 20 may be configured with one or more slots formed in the rigid carrier between the first and second proximity sensors as shown in fig. 35-37E. In the present embodiment, a single slot 610 is shown disposed between adjacent proximity sensors 24 to provide signal isolation between adjacent proximity sensors 24. It should be appreciated that one or more slots may be formed in the rigid carrier 12 between adjacent proximity sensors 24. In this embodiment, the groove 610 may also be used in conjunction with the recess 600 or may be used without the recess 600. By employing the combination of the recess 600 and the slot 610, enhanced signal detection and reduced signal interference may be achieved. By employing the slot 610 without the recess 600, a more compact proximity switch assembly 20 can be achieved with the proximity switch 22 located in close proximity without the increased size recess.

As seen in fig. 35 and 36, a slot 610 is shown formed in the upper surface of the rigid carrier 12 in the area between the first and second proximity sensors 24. The slot 610 may have a length L as shown_GIs shown as width W_GOf a second dimension, length L_GAt least the width W of the sensor 24_SAs long, or at least as long as W in the embodiment with recess 600_DIs equally long and, preferably, is longer than the width W_S5 to 10mm long or wider than the width W in the embodiment with the recess 600_DLength 0 to 5 mm, width W_GIn the range of 1 mm to 5 mm. The depth of the groove 610 may be in the range of 0.5 to 2.0 millimeters. It should be appreciated that the depth of the groove 610 may extend a substantial distance onto the upper surface of the rigid carrier 12. In one embodiment, the rigid carrier 12 is made of plastic. The slot 610 forms an air gap therein. The air gap has a low dielectric which effectively reduces the turn-on field in this region and reduces or prevents signal cross-talk or interference.

Referring to fig. 37A-37E, a proximity switch assembly 20 employing a flexible material 500, a recess 600, and a slot 610 is illustrated, in accordance with one embodiment. As shown in fig. 37A, the user's finger 34, shown in the first position, contacts the surface of the flexible material 500 at a location that is proximate to but laterally displaced from the proximity sensor 24. In fig. 37B, the user's finger 34 is shown moving by lateral sliding to a second position aligned with the first proximity sensor 24 without applying force or pressure to the flexible material 500. This may occur when the user is exploring the proximity sensor assembly 20 in the exploration/search mode without intending to turn on the proximity switch 22. In fig. 37C, the user's finger 34 is shown moving across the slot 610 to a third position aligned with the second proximity sensor by lateral sliding without applying force or pressure to the flexible material 500, such as may occur in an exploration/search mode. In fig. 37D, the user's finger 34 is shown sliding further to a fourth position in the area of the second proximity sensor 34. It should be appreciated that a user may press the flexible material 500 on either the first or second proximity sensor 24 to turn on the first or second proximity switch 22.

The sequence of events shown in fig. 37A-37D is further illustrated in the first and

second signal

608 and 609 responses shown in fig. 37E. The first signal 608 generated by the first proximity sensor 24 is shown at a first level 608A when the user's finger is in contact with the proximity switch assembly 20 at both the first and second positions as seen in fig. 37A and 37B. As the user's finger approaches the slot 610 between the first and second proximity sensors, the first signal 608 drops to a reduced or zero value. As the user's finger moves away from the slot 610 and approaches the third and fourth positions as shown in fig. 37C and 37D, the second signal 609 generated by the second proximity sensor 24 rises back to signal levels 608C and 608D. The results of the

signals

608 and 609 are at a reduced or zero value when the user's finger 34 crosses the slot 610 between the first and second proximity sensors 24. The slot 610 effectively isolates the

signals

608 and 609 to reduce the signal value to a smaller or zero value and thereby prevent interference between adjacent proximity sensors 24. The control circuit may thereby determine the opening of either of the first and second switches 22 based on the

signals

608 and 609 with reduced signal interference.

In accordance with yet another embodiment, it is further illustrated that the proximity switch assembly 20 is configured with a flexible material 500 and a recess 600 having a raised or elevated contact surface portion 620 shown in FIG. 38 aligned with each proximity sensor 24. In this embodiment, the raised surface 620 provides an increased travel distance between switch actuations, which may also serve as a tactile sensation to the user. According to one embodiment, the height of the raised surface 620 may be in the range of 1 to 2 millimeters. The raised surface 620 may keep the user's finger 34 farther away from the proximity sensor in the non-depressed state. It should be appreciated that a raised surface 620 having a depression 600 or one or more grooves 610, or having a depression 600 and one or more grooves 610, may be employed.

Accordingly, the proximity switch assembly 20 having the flexible material 500 may employ the recess 600 and/or the one or more slots 610 to provide enhanced signal detection and switch activation.

It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.

Claims

1. A proximity switch assembly, comprising:

a rigid carrier having an upper surface and a bottom surface;

a first proximity sensor disposed at a bottom surface of the carrier;

a second proximity sensor disposed at a bottom surface of the carrier adjacent to the first sensor with an area therebetween;

a flexible material disposed on an upper surface of the carrier; and

2. The proximity switch assembly according to claim 1, wherein the slot has a dimension that is longer than the sensor.

3. The proximity switch assembly according to claim 1, wherein the slot dimension exceeds the sensor by 5 to 10 millimeters.

4. The proximity switch assembly according to claim 1, wherein the flexible material is rubber.

5. The proximity switch assembly according to claim 1, wherein the slot has a thickness in a range of 0.5 to 2.0 millimeters.

6. The proximity switch assembly of claim 1, further comprising a control circuit that monitors an activation field associated with the proximity sensor and determines activation of the proximity switch based on a signal generated by the sensor about a threshold value when a finger of a user presses the flexible material.

7. The proximity switch assembly according to claim 1, further comprising a first recess formed on the rigid carrier between the flexible material and the first proximity sensor, wherein the first recess is formed within an upper surface of the rigid carrier and is spaced apart from the first proximity sensor.

8. The proximity switch assembly according to claim 7, further comprising a second recess formed on the rigid carrier between the flexible material and the second proximity sensor, wherein the second recess is formed in an upper surface of the rigid carrier and is spaced apart from the second proximity sensor.

9. The proximity switch assembly of claim 1, wherein the proximity switch comprises a capacitive switch including one or more capacitive sensors.

10. The proximity switch assembly according to claim 1, wherein the assembly is mounted on a vehicle.

11. A vehicle proximity switch assembly, comprising:

a rigid carrier having an upper surface and a bottom surface;

a first proximity sensor mounted on a bottom surface of the carrier;

a flexible material disposed on an upper surface of the carrier; and

12. The proximity switch assembly according to claim 11, wherein the slot has a dimension that is longer than the sensor.

13. The proximity switch assembly according to claim 11, wherein the slot dimension exceeds the sensor by 5 to 10 millimeters.

14. The proximity switch assembly according to claim 11, wherein the flexible material is rubber.

15. The proximity switch assembly according to claim 11, wherein the slot has a thickness in a range of 0.5 to 2.0 millimeters.

16. The proximity switch assembly of claim 11, further comprising a control circuit that monitors an activation field associated with the proximity sensor and determines activation of the proximity switch based on a signal generated by the sensor about a threshold value when a finger of a user presses the flexible material.

17. The proximity switch assembly according to claim 11, further comprising a first recess formed on the rigid carrier between the flexible material and the first proximity sensor, wherein the first recess is formed in an upper surface of the rigid carrier and is spaced apart from the first proximity sensor.

18. The proximity switch assembly according to claim 17, further comprising a second recess formed on the rigid carrier between the flexible material and the second proximity sensor, wherein the second recess is formed in an upper surface of the rigid carrier and is spaced apart from the second proximity sensor.

19. The proximity switch assembly of claim 11, wherein the proximity switch comprises a capacitive switch including one or more capacitive sensors.

20. The proximity switch assembly according to claim 11, wherein the assembly is mounted on a vehicle.