Patent Publication Number: US-2018041208-A1

Title: Capacitive Keypad, Vehicle Trim Component, Vehicle, and Method for Implementing Such Capacitive Keypad

Description:
TECHNOLOGICAL FIELD 
     The present description concerns a capacitive keypad, designed to equip a vehicle. The present description also concerns a vehicle trim component and a vehicle equipped with such capacitive keypad. The present description also concerns a method for implementing such capacitive keypad. 
     The field of the present description is that of capacitive keypads equipping automotive vehicles, especially for unlocking or locking vehicle openings such as doors and rear trunk. Generally, the user of the capacitive device is the vehicle driver. 
     BACKGROUND 
     CA2894297A1 discloses an example of capacitive keypad, configured to interact with a user via a swipe-up input. The vehicle controller is configured to control the vehicle operation in response to detecting the swipe-up input on the capacitive keypad, or another input via an application independent of the swipe-up input, within a predetermined time. 
     US2010315267A1 discloses an example of capacitive keypad, configured to unlock vehicle doors by pressing a series of keys according to a predetermined sequence, and to lock the doors by pressing two particular keys during a predetermined time. 
     WO2015168459A1 discloses another example of capacitive keypad, integrating a NFC device. 
     In practice, inadvertent actuation of capacitive keys may occur. Such inadvertent actuation may be exacerbated by environmental factors such as rain, frost, and condensation. In some instances, a user may touch one capacitive key and moisture on the keypad may cause cross-talk with another capacitive key. Thus, a complex touch area suppression algorithm is provided to prevent inadvertent actuation from cross-talk. 
     SUMMARY OF THE DISCLOSURE 
     The aim of the presently described embodiments is to provide an improved capacitive keypad, having an improved sensor arrangement. 
     To this end, the described embodiments concern a capacitive keypad, designed to equip a vehicle, comprising several capacitive keys and configured to activate particular functions, including a primary lock function, consisting in locking or unlocking at least one vehicle opening; and a secondary lock function, consisting in locking the at least one vehicle opening by a user equipped with a passive entry device. According to the described embodiments, the particular functions further include an antiswipe function, consisting in deactivating one of the lock functions among the primary lock function and the secondary lock function, upon droplet detection or finger slippage detection. Furthermore, a single specific key among the capacitive keys is configured to selectively activate either the secondary lock function or the antiswipe function of the capacitive keypad. 
     Thanks to the presently described embodiments, the capacitive keypad is provided with several functions while being compact, in comparison with a capacitive keypad having separated functions associated with separated capacitive keys. 
     Moreover, the presently described embodiments allows reducing the number of printed tracks arranged under the capacitive keys acting as sensors, the number of connectors linking the sensors arranged on the printed tracks to an electronic card, and the size of the processor arranged on the electronic card. 
     According to further aspects of the presently described embodiments which are advantageous but not compulsory, such a capacitive keypad may incorporate one or several of the following features: 
     The antiswipe function is configured to deactivate the primary lock function, upon droplet detection or finger slippage detection by the specific key. 
     The antiswipe function is configured to deactivate the secondary lock function, upon droplet detection or finger slippage detection by an other key than the specific key. 
     The other key is positioned directly next to the specific key. 
     The other key is positioned directly above the specific key. 
     The specific key is positioned under other capacitive keys. 
     The specific key displays a padlock symbol. 
     The specific key displays a closed padlock symbol when the at least one vehicle opening is closed and an opened padlock symbol when the at least one vehicle opening is opened. 
     The primary lock function and the secondary lock function are associated with all vehicle openings, including several doors and at least one trunk. 
     The presently described embodiments also concern a method for implementing a capacitive keypad as mentioned here-above, wherein the method comprises a step of selectively activating the secondary lock function or the antiswipe function of the capacitive keypad by contacting the specific key. 
     Preferably, the antiswipe function is automatically activated upon droplet detection or finger slippage detection by the specific key, while the secondary lock function is manually activated by a user equipped with a passive entry device and pressing the specific key. 
     The presently described embodiments also concern a capacitive keypad, designed to equip a vehicle, comprising several capacitive keys and configured to activate particular functions including a primary lock function, consisting in locking or unlocking at least one vehicle opening; and a secondary lock function, consisting in locking the at least one vehicle opening by a user equipped with a passive entry device. According to the presently described embodiments, the particular functions further include an antiswipe function, consisting in deactivating one of the lock functions among the primary lock function and the secondary lock function, upon droplet detection or finger slippage detection. Furthermore, a first key among the capacitive keys is configured to activate the antiswipe function for deactivating the primary lock function, while a second key different from the first key is configured to activate the antiswipe function for deactivating the secondary lock function. 
     The presently described embodiments also concern a method for implementing a capacitive keypad as mentioned here-above, wherein the method comprises a step of activating the antiswipe function for deactivating the primary lock function upon droplet detection or finger slippage detection by the first key or for deactivating the secondary lock function upon droplet detection or finger slippage detection by the second key. 
     The presently described embodiments also concern a vehicle trim component equipped with a capacitive keypad as mentioned here-above. Preferably, the vehicle trim component is a vehicle pillar member. 
     The presently described embodiments also concern a vehicle equipped with a capacitive keypad as mentioned here-above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Contemplated embodiments will now be explained in correspondence with the annexed figures, and as an illustrative example, without restricting the object of the embodiments described. In the annexed figures: 
         FIG. 1  is a partial front view of a vehicle trim component, equipped with a capacitive keypad, displaying a closed padlock symbol; and 
         FIG. 2  is a view at a larger scale of the capacitive keypad of  FIG. 1 ; 
         FIG. 3  is a bottom view of the capacitive keypad of  FIG. 2 ; 
         FIG. 4  is a view similar to  FIG. 2 , with the capacitive keypad displaying an opened padlock symbol. 
     
    
    
     DETAILED DESCRIPTION OF SOME EMBODIMENTS 
       FIGS. 1 to 4  show a capacitive keypad  10  according to the described embodiments, equipping a vehicle  1  partly represented for simplification purpose. 
     More precisely, keypad  10  is integrated to a vehicle trim component  2 , preferably a vehicle pillar member. 
     Keypad  10  includes six capacitive keys  11 ,  12 ,  13 ,  14 ,  15  and  16  connected to an electronic control unit  20  also integrated to component  2 . The electric connection between keys  11 - 16  and unit  20  is done via printed tracks  30 ,  31 ,  32 ,  33 ,  34 ,  35 ,  36  and connectors  40 . 
     Unit  20  may comprise an electronic card formed by a printed circuit board, provided with electronic elements including a processor. Unit  20  is connected to the onboard computer of vehicle  1 . Alternatively, unit  20  may be deported to another location of the vehicle  1 , or be directly integrated to the onboard computer of vehicle  1 . 
     Keypad  10  has a tactile function, known per se. The tactile function of keypad  10  is enabled by default but can be disabled under certain conditions, as detailed below. 
     Keys  11 - 16  can be reached on the external surface  3  of component  2  by a user of vehicle  1 . Thus, the user can generate signals directed to the electronic control unit  20  by pressing surface of keys  11 - 16 , acting as pressure sensors. 
     In particular, some signals are intended to lock the openings of vehicle  1 , by typing a numeric code corresponding to a predetermined sequence of keys  11 - 15 . Generally, those openings include the doors and the rear trunk of vehicle  1 . 
     Keypad  10  is a capacitive system, known per se. Keypad  10  includes a capacitive layer designed to accumulate electrical charges. When the user touches the surface of keypad  10  with his finger, some of these charges are transferred to said finger. Charges leaving the capacitive layer create a measurable deficit, allowing detection of a push on a given key  11 - 16 . The capacitance associated to each key  11 - 16  can be measured and transmitted to unit  20 , either continuous or at regular intervals. 
     For example, the variations of charges may be measured by means of electrodes positioned under keypad  10  and connected to unit  20  via printed tracks  30 - 36  and connectors  40 . 
     Keys  11 - 15  each have two digits, namely digits “1” and “2” on key  11 , digits “3” and “4” on key  12 , digits “5” and “6” on key  13 , digits “7” and “8” on key  14 , and digits “9” and “0” on key  15 . Thus, keypad  10  is more compact in comparison with a keypad provided with ten keys, each having a single digit. 
     A predetermined pressing sequence on keys  11 - 15  sends a numeric code to unit  20 , which then controls locking or unlocking of the openings of vehicle  1  when the code is correct. 
     In practice, a push on key  11  sends a signal corresponding to both digits “1” and “2” indistinctly, and so on for keys  12 - 15 . That allows defining a numeric code based on ten digits, without requiring double-pushes for typing even digits. 
     According to the described embodiments, keypad  10  is configured to activate several particular functions, including a primary lock function, a secondary lock function and an antiswipe function described here-below. 
     The primary lock function is configured to lock or unlock at least one vehicle opening. The primary lock function is controlled by keys  11 - 15 . For example, locking is activated by simultaneously pressing keys  14  and  15  during a predetermined time (generally around one second), while unlocking is activated by pressing a predetermined sequence of several keys  11 - 15 . 
     The secondary lock function is configured to lock the at least one vehicle opening by a user equipped with a passive entry device, such as an electronic key fob, in wireless communication with vehicle  1 . In the context of the contemplated embodiments, the onboard computer of vehicle  1  is provided with a PEPS function (Passive Entry Passive Start) configured to check if the electronic key fob is located inside or outside vehicle  1 . 
     In practice, the locking is automatically performed when the user equipped with the passive entry device moves away from a certain distance from the vehicle. However, the locking via primary lock function and keys  11 - 15  cannot be activated when the user is close to the vehicle. Under those conditions, the secondary lock function provides a manual lock function in combination with the use of the passive entry device. 
     The antiswipe function is configured to deactivate one of the lock functions upon droplet or finger slippage detection, as detailed here-after. 
     Preferably, the primary lock function and the secondary lock function are associated with all openings, including generally several doors and at least one trunk, of vehicle  1 . 
     According to the described embodiments, key  16  is a specific capacitive key among all keys  11 - 16 , in that key  16  is configured to selectively activate both the secondary lock function and the antiswipe function of keypad  10 . 
     Depending on the pressing sequence on keys  11 - 16 , key  16  is configured to activate either the secondary lock function or the antiswipe function. 
     Thus, the described embodiments allow reducing the number of printed tracks  30 - 36  arranged under keys  11 - 16  acting as sensors, the number of connectors  40  linking the sensors to the electronic card, and the size of the processor arranged on the electronic card. 
     Besides, since no additional key is arranged between key  16  and connectors  40 , the printed track  36  linking key  16  to its connector  40  can be very short. 
     Preferably, the antiswipe function is automatically activated upon droplet detection or finger slippage detection on key  16 , while the secondary lock function is manually activated by a user equipped with a passive entry device and pressing the specific key  16 . 
     On the example of  FIGS. 1 to 4 , key  16  is located under other keys  11 - 15  and displays a padlock symbol. More precisely, key  16  displays a red closed padlock symbol  61  when the openings of vehicle  1  are closed ( FIGS. 1 and 2 ) and a green opened padlock symbol  62  when the openings of vehicle  1  are opened ( FIG. 4 ). 
     According to a first embodiment, the anstiswipe function is configured to deactivate the primary lock function upon droplet detection or finger slippage detection on key  16 , but not configured to deactivate the secondary lock function. 
     In case of pressure detection simultaneously on keys  14  and  15 , while a pressure has previously been detected by key  16 , the anstiswipe function deactivates the primary lock function, which prevents locking of vehicle  1 . 
     In case of pressure detection on keys  11  to  15 , while a pressure has previously been detected on key  16 , the anstiswipe function deactivates the primary lock function, which prevents unlocking of vehicle  1  if the predetermined unlocking sequence has been fortuitously typed. 
     According to a second embodiment, the antiswipe function is configured to selectively deactivate the primary lock function or the secondary lock function. More precisely, the anstiswipe function is configured, on the one hand, to deactivate the primary lock function upon droplet or finger slippage detection by key  16 , as described here-above and, on the other hand, to deactivate the secondary lock function upon droplet or finger slippage detection by another key, preferably by key  15  located directly above key  16 . 
     In case of pressure detection on key  16 , while a pressure has previously been detected by key  15 , the anstiswipe function deactivates the secondary lock function, which prevents locking of vehicle  1  by the user equipped with the passive entry device. 
     In this embodiment, keys  15  or  16  are configured to selectively activate the antiswipe function, but only key  16  is configured to selectively activate both the secondary lock function or the antiswipe function. 
     Keypad  10  also has a non-capacitive space  17  located above key  11 . Alternatively, space  17  may be capacitive and control other features of keypad  10 , which will not be described in so far as they are not object of the present description. 
     Keypad  10  also includes a light emitting diode  18  between key  11  and space  17 , allowing for example to warn the user that he typed a correct or incorrect code 
     Other non-shown embodiments can be implemented within the scope of the description. In addition, technical features of the different embodiments can be, in whole or part, combined with each other. Thus, keypad  10  can be adapted to the specific requirements of the application.