Shared Pin Circuit With Impedance Filtering for Keyboard and Touch Panels

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Solution Overview

Problem

The complexity and cost of chip packaging increase due to the need for multiple pins on integrated circuits to control both keyboard devices and touch panels, which require different stimulation signals, leading to signal interference between the two.

Innovation Solution

A pin sharing circuit with an integrated circuit and a wire containing an impedance element, such as a passive element or diode, is used to filter out the AC component of the stimulation signal, allowing the same pin to be shared between the keyboard device and touch panel without interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate pins are used for keyboard device and touch panel, then signal interference is avoided, but the number of pins on integrated circuit increases

Engineering Contradiction:

Improvesignal interference preventionVSAvoidnumber of pins

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the pins for keyboard device and touch panel into a shared pin structure. The integrated circuit uses a common pin that can be selectively connected to either the keyboard device or the touch panel through switching mechanisms, thereby reducing the total number of pins while maintaining signal integrity and preventing interference between the two devices.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The shared pin is designed with multi-functionality to serve both the keyboard device and the touch panel. By implementing a pin that can dynamically switch between different device connections, the system achieves universal pin usage, reducing pin count while ensuring that each device receives appropriate dedicated signal paths when active.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Device complexity

If pins are shared between keyboard device and touch panel, then the number of pins is reduced, but signal conflicts occur

Engineering Contradiction:

Improvenumber of pinsVSAvoidsignal conflict prevention

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent implements dynamic pin assignment where the connection of the shared pin to either the keyboard device or the touch panel is not fixed but can change based on operational requirements. Switching mechanisms dynamically connect the shared pin to the appropriate device, ensuring that signal conflicts are prevented while maintaining the benefits of pin sharing.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent introduces switching mechanisms as intermediary components between the shared pin and the two devices. These intermediaries control the signal flow, ensuring that only one device is connected to the shared pin at a time, thereby preventing signal conflicts while allowing the pin to be shared between multiple devices.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If multiple pins are used on integrated circuit, then manufacturing cost increases, but signal quality is maintained

Engineering Contradiction:

Improvesignal qualityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

By merging the pin structures for the keyboard device and touch panel into a shared configuration, the patent reduces the total number of pins required on the integrated circuit. This consolidation directly lowers manufacturing costs associated with chip packaging while maintaining signal quality through dedicated switching paths that ensure clean signal transmission to each device when active.

Inventive Principle:

Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution enhances system efficiency by enabling the sharing of pins while preventing signal conflicts, thereby reducing the number of pins required on the integrated circuit and minimizing manufacturing costs.

Implementation Method 1

The first wire includes a first impedance element coupled between the input terminal of the keyboard device and the at least one first shared pin and configured to filter the stimulation signal so as to filter out the AC component of the stimulation signal

Methodology Applied

Scientific EffectImpedance filtering: Filter (electronic)

Data Source

PatentUS10261687B2Pin sharing circuit, pin sharing method, electronic device and electronic wire using the same

Publication Date: 2019.04.16 PIXART IMAGING INC

AI summary

Provided herein are a pin sharing circuit, a pin sharing method and an electronic device, an electronic wire using the same. The pin sharing circuit enables at least one pin on an integrated circuit to be shared by a keyboard device and a touch panel and prevents signal interference between the keyboard device and the touch panel using an impedance element disposed on a wire for the pin, such that the pin can output or receive a stimulation signal and a sensor signal that contain both an AC component and a DC component so as to enhance the efficiency of the overall system and prevent the stimulation signal and the sensor signal from conflicts between the keyboard device and the touch panel.