System and method for capacitive information handling system housing and perimeter sensors
A system and method to detect user presence near and capacitive touch of a user at an exterior chassis housing of an information handling system that includes a hardware processor, a data storage device, and a power management unit (PMU) to provide power to the hardware processor and data storage device. The system includes an exterior chassis housing capacitive sensor to detect user proximity near or touch of on an exterior chassis housing surface of the information handling system and a perimeter capacitive sensor to detect user grip of the information handling system when a grounding source of the exterior chassis housing is removed during periodic, brief sense state time duration windows. A capacitive sensor microprocessor to periodically switch the exterior chassis housing capacitive sensor and perimeter capacitive sensor to a sense state to detect user proximity to, capacitive touch of, or grip of the exterior chassis housing.
1 . An information handling system executing computer-readable program code instructions to detect user presence near and capacitive touch of a user at an exterior chassis housing of the information handling system comprising:
a hardware processor, a data storage device, and a power management unit (PMU) to provide power to the hardware processor and data storage device;
an exterior chassis housing capacitive sensor to detect user proximity near the exterior chassis housing of the information handling system and user touch on a surface of the exterior chassis housing when a grounding source of the exterior chassis housing is decoupled;
a perimeter capacitive sensor on the exterior chassis housing to detect user grip of the exterior chassis housing of the information handling system;
a capacitive sensor microprocessor operatively coupled to the exterior chassis housing capacitive sensor and perimeter capacitive sensor to periodically switch the exterior chassis housing capacitive sensor and perimeter capacitive sensor to a sense state to detect user proximity capacitance levels for the user proximity, capacitive touch capacitance levels for the capacitive touch, and grip capacitance levels for the grip by a user; and
the capacitive sensor microprocessor to transmit detected user proximity of the user, detected capacitive touch of the user, or detected grip by the user of the exterior chassis housing to the hardware processor of the information handling system for use as capacitive sensor input or capacitive input commands.
2 . The information handling system of claim 1 further comprising:
the capacitive sensor microprocessor to periodically decouple the grounding source of the exterior chassis housing and switch the exterior chassis housing capacitive sensor and perimeter capacitive sensor to a sense state during plural periodic, brief sense state time duration windows.
3 . The information handling system of claim 1 wherein each periodic, brief sense state time duration window is less than 15 milliseconds in duration and an interval period between the periodic, brief sense state time duration windows is greater than 0.3 seconds.
4 . The information handling system of claim 1 further comprising:
the exterior chassis housing decoupled from the grounding source via a high-pass frequency capacitor to ground high frequency interference and an electrostatic discharge diode.
5 . The information handling system of claim 1 further comprising:
the perimeter capacitive sensor having a capacitive sensing layer and an adhesive layer for operatively coupling to the surface of the exterior chassis housing; and
an electrical lead operatively coupling the capacitive sensing layer to the capacitive sensor microprocessor through a via formed through the adhesive layer and the exterior chassis housing of the information handling system.
6 . The information handling system of claim 1 further comprising:
the perimeter capacitive sensor having a capacitive sensing layer, an insulating layer, an active shield layer, and an adhesive layer for operatively coupling to the surface of the exterior chassis housing; and
an electrical lead operatively coupling the capacitive sensing layer to the capacitive sensor microprocessor with a via formed through the second insulating layer, the active shield layer, the adhesive layer, and the exterior chassis housing of the information handling system, where the active shield layer shields the perimeter capacitive sensor from the exterior chassis housing operating as the exterior chassis housing capacitive sensor.
7 . The information handling system of claim 1 further comprising:
the exterior chassis housing capacitive sensor switched to the sense state by operatively coupling the exterior chassis housing to a capacitive sensor driver circuit and disconnecting the exterior chassis housing from the grounding source during periodic, brief sense state time duration windows.
8 . The information handling system of claim 1 further comprising:
the perimeter capacitive sensor switched to the sense state by operatively coupling the exterior chassis housing capacitive sensor to a capacitive sensor driver circuit and disconnecting the perimeter capacitive sensor from the grounding source during periodic, brief sense state time duration windows.
9 . A method executing computer-readable program code instructions to detect user presence near and capacitive touch of a user at an exterior chassis housing of an information handling system comprising:
detecting user proximity near the exterior chassis housing of the information handling system and user touch on a surface of the exterior chassis housing with an exterior chassis housing capacitive sensor driven by a capacitive sensor driver circuit and a capacitive sensor microprocessor when a grounding source of the exterior chassis housing is decoupled, where the capacitive sensor microprocessor periodically switches the exterior chassis housing capacitive sensor and a perimeter capacitive sensor to a sense state to detect user proximity capacitance levels and capacitive touch capacitance levels;
detecting user grip of the information handling system via the perimeter capacitive sensor operably coupled to a surface of the exterior chassis housing when the grounding source of the exterior chassis housing is decoupled; and
transmitting, via the capacitive sensor microprocessor a detected user proximity, a detected user touch, or a detected user grip as capacitive sensing input to the hardware processor of the information handling system.
10 . The method of claim 9 further comprising:
decoupling the grounding source of the exterior chassis housing and sequentially switching the exterior chassis housing capacitive sensor and perimeter capacitive sensor, via the capacitive sensor microprocessor, to a sense state during periodic, brief sense state time duration windows.
11 . The method of claim 10 , wherein each periodic, brief sense state time duration window is less than 15 milliseconds in duration and an interval period between the periodic, brief sense state time duration windows is greater than 0.3 seconds.
12 . The method of claim 9 further comprising:
decoupling the grounding source of the exterior chassis housing via a high-pass frequency capacitor to ground high frequency interference and an electrostatic discharge diode.
13 . The method of claim 9 further comprising:
apply voltage to an active shield layer disposed between the exterior chassis housing operation as the exterior chassis housing capacitive sensor and the perimeter capacitive sensor similar to the voltage of the exterior chassis housing capacitive sensor via the capacitive microprocessor.
14 . The method of claim 9 , wherein the perimeter capacitive sensor is placed into a rubber foot formed on a bottom surface of the exterior chassis housing of the information handling system.
15 . The method of claim 9 further comprising:
the exterior chassis housing capacitive sensor switched to the sense state by operatively coupling the exterior chassis housing to the capacitive sensor driver circuit and decoupling the exterior chassis housing from the grounding source; and
the perimeter capacitive sensor switched to the sense state by operatively coupling the exterior chassis housing capacitive sensor to the capacitive sensor driver circuit and disconnecting the perimeter capacitive sensor from the grounding source.
16 . An information handling system executing computer-readable program code instructions to detect user presence near and capacitive touch of a user at an exterior chassis housing of the information handling system comprising:
a hardware processor, a data storage device, and a power management unit (PMU) to provide power to the hardware processor and data storage device;
the exterior chassis housing being activated with a capacitive sensor driver circuit as an exterior chassis housing capacitive sensor to detect user proximity near the exterior chassis housing of the information handling system and user touch on a surface of the exterior chassis housing when a grounding source of the exterior chassis housing is decoupled;
a perimeter capacitive sensor on the exterior chassis housing to be activated by the capacitive sensor driver circuit to detect user grip of the exterior chassis housing of the information handling system when the grounding source of the exterior chassis housing is decoupled;
a capacitive sensor microprocessor operatively coupled to the exterior chassis housing capacitive sensor and perimeter capacitive sensor to periodically switch the exterior chassis housing capacitive sensor and perimeter capacitive sensor to a sense state to detect user proximity capacitance levels for the user proximity, capacitive touch capacitance levels for the capacitive touch, and grip capacitance levels for the grip by a user; and
the capacitive sensor microprocessor to transmit detected user proximity of the user, detected capacitive touch of the user, or detected grip by the user of the exterior chassis housing to the hardware processor of the information handling system for use as capacitive sensor input or capacitive input commands.
17 . The information handling system of claim 16 further comprising:
the perimeter capacitive sensor formed on the exterior chassis housing with a first insulating layer, a capacitive sensing layer, a second insulating layer, an active shield layer, and an adhesive layer; and
an electrical lead operatively coupling the capacitive sensing layer to the capacitive sensor microprocessor through a via formed through the second insulating layer, active shield layer, the adhesive layer, and the exterior chassis housing of the information handling system.
18 . The information handling system of claim 16 further comprising:
the capacitive sensor microprocessor to periodically decouple the grounding source of the exterior chassis housing and sequentially switch the exterior chassis housing capacitive sensor and perimeter capacitive sensor to a sense state during each of plural periodic, brief sense state time duration windows.
19 . The information handling system of claim 17 further comprising:
the capacitive sensor microprocessor to periodically decouple the grounding source of the exterior chassis housing and simultaneously switch the exterior chassis housing capacitive sensor and perimeter capacitive sensor to a sense state during plural periodic, brief sense state time duration windows.
20 . The information handling system of claim 16 further comprising:
the exterior chassis housing decoupled from the grounding source via a high-pass frequency capacitor to ground high frequency interference and an electrostatic discharge diode.