Capacitive Touchpen Segmented Conductive Tip for Pressure and Tilt Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitive touch sensors struggle to accurately measure pen pressure and tilt using passive pens, as they rely on pointer size interpretations, which are inadequate for precise pen input, especially with small tips like graphite pens, limiting the sensitivity and feedback in drawing and writing applications.
Innovation Solution
A capacitive touchpen with an elongated conductive body and a thinner conductive tip that generates a capacitive footprint based on position changes, allowing detection of both pressure and tilt without additional sensors, by measuring the distortion of the electrostatic field caused by the conductive part, enabling precise pen input similar to active pen technology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a small tip is used for better visual feedback during drawing, then drawing precision is improved, but the ability to measure pressure is lost
Solution Approach 1:
The pen is divided into two distinct conductive components: a small tip for precise visual feedback and a larger conductive body portion for pressure sensing. The tip contacts the screen at a precise point while the body portion, being larger and softer, deforms under pressure to provide measurable capacitive changes.
Solution Approach 2:
Different parts of the pen have different properties optimized for different functions. The tip is small and hard for precise positioning and visual feedback, while the body portion is larger and softer to allow deformation under pressure, enabling pressure measurement without compromising drawing precision.
2Device complexity
If passive pen technology is used to reduce cost, then device complexity is reduced, but the ability to detect tilt and pressure is lost
Solution Approach 1:
The passive pen itself generates the sensing capability through its conductive body portion that deforms under pressure and tilts. No additional sensors or active electronics are needed in the pen - the capacitive material in the body portion serves dual purposes: maintaining electrical connection and providing pressure/tilt sensing through its physical deformation.
Solution Approach 2:
The conductive body portion serves multiple functions simultaneously: it maintains electrical connection with the capacitive sensor, provides pressure sensing through deformation, and enables tilt detection through its orientation-dependent capacitive coupling. This multi-functionality is achieved without adding separate sensing components.
3Measurement precision
If a large soft pen tip is used to measure pressure, then pressure measurement is improved, but visual feedback during drawing deteriorates
Solution Approach 1:
The pen is divided into two distinct conductive components: a small tip for precise visual feedback and a larger conductive body portion for pressure sensing. The tip contacts the screen at a precise point while the body portion, being larger and softer, deforms under pressure to provide measurable capacitive changes.
4Ease of operation
If graphite pens are used for writing, then writing capability is improved, but the ability to measure pressure is lost due to stiff material
Solution Approach 1:
The pen combines graphite material (providing writing capability and conductivity) with a softer structural material (allowing deformation). The graphite forms the conductive core while the softer outer material enables the pen body to deform under pressure, combining the advantages of both material types.
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
Enables accurate detection of pen position, tilt, and pressure without additional cost, allowing for detailed drawing and writing with passive pens, enhancing the sensitivity and feedback in capacitive touch systems.
Implementation Method 1
the distortion of the screen's electrostatic field caused by the conductive part when changing the position of the touchpen in relation to the capacitive touch panel
Implementation Method 2
is sufficient to register a change in capacitance by the capacitive touch panel
Data Source
AI summary
The disclosure relates to the technical field of capacitive touch panels and discloses a touchpen which may be used in mobile phones, computers and other devices with touch panels for writing characters, letters and other symbols. In particular it relates to a capacitive touchpen 10 for inputting information into an electronic device 1 through touching of a capacitive touch panel 30, the capacitive pen comprising an elongated body member 11 comprising a conductive part 13 and a tip 12 disposed at one end of the body member 11 having a contact surface 14 for contacting the capacitive touch panel 30. The conductive part 13 is configured such that the distortion of the touch panel's electrostatic field caused by the conductive part 13 when changing the position of the touchpen 10 in relation to the capacitive touch panel 30, when the contact surface is kept in contact with the touch panel 30, is sufficient to register a change in capacitance by the capacitive touch panel 30. The disclosure further relates to methods for detecting the position of a touch pen as well as to an electronic device and a computer program.