WATER IMMUNE KEYPAD

• US 20150360647A1
• Filed: 06/09/2015
• Published: 12/17/2015
• Est. Priority Date: 06/12/2014
• Status: Active Grant

• Current Assignee: Methode Electronics Incorporated
• Original Assignee: Methode Electronics Incorporated
• Inventors: MATHEWS, Mark R.
• Granted Patent: US 9,965,983 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G09G 3/04 for presentation of a single character by selection from a plurality of characters, or by composing the character by combination of individual elements, e.g. segments using a combination of such display devices for composing words, rows or the like, in a frame with fixed character positions
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2017/9602 characterised by the type or shape of the sensing electrodes

Abstract

A keyless entry system for an automobile includes a capacitive touch screen having at least one drive line and at least one sense line, the drive and sense lines defining a plurality of touch detection nodes. The touch screen is associated with an exterior surface of the automobile. A control circuit coupled to the touch screen is configured to detect proximity of a stimulus to the touch detection nodes. The control circuit provides a control output to a lock or latch controller when the control circuit determines that the stimulus has been placed proximate the touch detection nodes according to predetermined criteria.

Claims

1. A method of using a capacitive touch screen having a plurality of touch detection nodes in a keyless entry system for a vehicle, comprising the steps of:

associating said capacitive touch screen with an exterior surface of said vehicle;

defining a plurality of touch detection zones on said capacitive touch screen, each of said touch detection zones overlying corresponding ones of said touch detection nodes;

associating a touch screen controller with said capacitive touch screen, said touch screen controller configured to detect touch or proximity of a stimulus to ones of said plurality of touch detection nodes and to provide an output indicative of said touch or proximity and the location of said touch or proximity with respect to the form of said touch screen; and

associating a control circuit with said touch screen controller, said control circuit configured to provide a control output only when said touch screen controller detects touch to a first predetermined number of said touch detection nodes underlying a specific one of said plurality of touch detection zones within a predetermined time.

2. The method of claim 1, said control circuit further configured to not provide said control output if said touch screen controller detects touch to a second predetermined number of said touch detection nodes not underlying said specific one of said plurality of touch detection zones within said predetermined time.

3. The method of claim 1, said control circuit further configured to provide said control output only if said touch screen controller first detects touch to said first predetermined number of said touch detection nodes underlying said specific one of said plurality of touch detection zones within said predetermined time and said touch screen controller then detects touch to a first predetermined number of said touch detection nodes underlying a second specific one of said plurality of touch detection zones within a further predetermined time.

4. The method of claim 3 wherein said control output causes locking or unlocking of an entry point of said vehicle.

5. The method of any preceding claim 4 wherein said capacitive touch screen is disposed upon a surface of a said vehicle

6. The method of claim 2, said control circuit further configured to provide said control output only if said touch screen controller first detects touch to said first predetermined number of said touch detection nodes underlying said specific one of said plurality of touch detection zones within said predetermined time and said touch screen controller then detects touch to a first predetermined number of said touch detection nodes underlying a second specific one of said plurality of touch detection zones within a further predetermined time.

7. The method of claim 1 wherein said capacitive touch screen comprises at least one drive line and at least two sense lines.

8. The method of claim 1 wherein said capacitive touch screen comprises at least two drive lines and at least one sense line.

9. The method of claim 1 wherein said control circuit comprises a high signal-to-noise ratio touch screen controller.

10. The method of claim 9 wherein the touch screen controller comprises analog circuitry and noise filtering algorithms.

11. The method of claim 1 wherein said capacitive touch screen further comprises hard coded graphics identifying the location of said plurality of touch detection zones.

12. A keyless entry system for a vehicle, comprising:

a capacitive touch screen comprising a dielectric substrate having a first side and a second side, at least one drive line disposed on said first side of said dielectric substrate and at least one sense line disposed on said second side of said dielectric substrate, said at least one drive line and said at least one sense line defining a plurality of touch detection nodes, said capacitive touch screen associated with an exterior surface of said vehicle, said capacitive touch screen defining a plurality of touch detection zones, each of said touch detection zones overlying corresponding ones of said touch detection nodes;

a touch screen controller electrically coupled to said capacitive touch screen, said touch screen controller configured to detect touch or proximity of a stimulus to ones of said plurality of touch detection nodes and to provide an output indicative of said touch or proximity and the location of said touch or proximity with respect to the form of said touch screen; and

a control circuit electrically coupled to said touch screen controller, said control circuit configured to provide a control output only when said touch screen controller detects touch to a first predetermined number of said touch detection nodes underlying a specific one of said plurality of touch detection zones within a predetermined time.

13. The system of claim 12, said control circuit further configured to not provide said control output if said touch screen controller detects touch to a second predetermined number of said touch detection nodes not underlying said specific one of said plurality of touch detection zones within said predetermined time.

14. The system of claim 13 wherein said control output causes locking or unlocking of an entry point of said vehicle.

15. The system of claim 13, said control circuit further configured to provide said control output only if said touch screen controller first detects touch to said first predetermined number of said touch detection nodes underlying said specific one of said plurality of touch detection zones within said predetermined time and said touch screen controller then detects touch to a first predetermined number of said touch detection nodes underlying a second specific one of said plurality of touch detection zones within a further predetermined time.

16. The system of claim 12 further comprising hard coded graphics disposed on said capacitive touch screen, said hard coded graphics identifying the location of said plurality of touch detection zones.

17. The system of claim 12, said touch detection zones arranged in plural rows and a single column on said capacitive touch screen.

18. The system of claim 12, said touch detection zones arranged in a single row and plural columns on said capacitive touch screen.

19. The system of claim 12, said touch detection zones arranged in plural rows and plural columns on said capacitive touch screen.