Motion based capacitive sensor system

• US 10,409,426 B2
• Filed: 04/14/2015
• Issued: 09/10/2019
• Est. Priority Date: 04/14/2015
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Buttolo, Pietro, Lobo, Harry, Rankin, II, James Stewart, Ritter, Kassandra, Ghosh, Dipanjan, Salter, Stuart C., Smith, Jessica
• Primary Examiner(s): Mengistu, Amare
• Assistant Examiner(s): Mathews, Crystal
• Application Number:
  US14/686,243
• Publication Number:
  US 20160306455A1
• Time in Patent Office: 1,610 Days
• CPC Class Codes: B60R 25/23 using manual input of alphanumerical codes
• CPC Class Codes: E05B 81/77 comprising sensors detecting the presence of the hand of a user
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 2017/9602 characterised by the type or shape of the sensing electrodes
• CPC Class Codes: H03K 2217/94036 Multiple detection, i.e. where different switching signals are generated after operation of the user is detected at different time instants at different locations during the actuation movement by two or more sensors of the same or different kinds

Abstract

A proximity sensing system may include a conductive first trace and a conductive second trace adjacent to, interleaved with, and electrically isolated from the first trace. A density of the traces varies along a first axis such that rates of change of capacitance between the traces associated with movement, through an electric field, of an object in a direction of the first axis at a constant velocity are indicative of the direction. The sensing system may further include a conductive third trace adjacent to, interleaved with, and electrically isolated from the first trace. A first area between the first trace and second trace is independent of and isolated from a second area between the first trace and the third trace. Also, a density of the first and third traces may vary along the first axis.

Claims

1. A sensing system comprising:

electrically isolated and interleaved conductive transmitting and receiving traces, a density of the traces varying along two axes such that rates of change of a single capacitance signal from the receiving trace associated with movement of an object through an electric field associated with the traces describes, in two dimensions, a direction of the movement; and

a controller to output a signal indicating the direction based on the single capacitance signal.

2. The sensing system of claim 1 further including:

a conductive second receiving trace adjacent to, interleaved with, and electrically isolated from the transmitting trace.

3. The sensing system of claim 2 further comprising:

a display, wherein the controller is further programmed to

increment a modulo counter in response to a first signal based on a first change in capacitance between the transmitting and receiving traces,

output a value of the counter on the display,

enter the value of the counter in a memory in response to a second signal based on a second change in capacitance between the transmitting and second receiving traces to generate an access code, and

unlock a door lock system based on the access code matching a key code.

4. The sensing system of claim 2, wherein the controller is further programmed to

generate an access code in response to a sequence of swipes, each swipe based on a second signal being a change in capacitance between the transmitting and second receiving traces, and

unlock a door lock based on the access code matching a key code.

5. The sensing system of claim 1, wherein the transmitting and receiving traces define a pattern that is asymmetrical.

6. The sensing system of claim 5, wherein the pattern is trapezoidal, square or circular.