Input Device Calibration Using Position-Encoded Film Offset

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Solution Overview

Problem

Existing input devices face accuracy issues due to misalignment between position-encoded films and pixel arrays on computing device displays, leading to improper operation and control of the device.

Innovation Solution

An input device with a calibrator that uses a sensor to detect its position relative to a position-encoded film and pixel array, calculating a calibration transformation to account for misalignment and enhance accuracy by determining first coordinates of the position-encoded film and second coordinates of the pixel array, and calculating a calibration transformation to control the computing device based on the offset.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If position-encoded film is used to detect input device location, then location detection capability is improved, but misalignment between position-encoded film and pixel array causes calibration accuracy to deteriorate

Engineering Contradiction:
Improvelocation detection capabilityVSAvoidcalibration accuracy
Core Design Contradiction:
Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary calibration process that detects the relative offset between the position-encoded film and pixel array. This intermediary calibration data is then used to transform coordinates from the position-encoded film reference frame to the pixel array reference frame, resolving the misalignment issue while preserving location detection capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the reference frame parameter by detecting the offset between position-encoded film coordinates and pixel array coordinates. This parameter change allows the system to compensate for misalignment by applying coordinate transformations, thereby improving calibration accuracy without sacrificing location detection capability.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If calibration transformation is calculated to account for misalignment, then calibration accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvecalibration accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The input device performs self-calibration by automatically detecting the offset between position-encoded film and pixel array, and calculating the necessary calibration transformation. This self-service approach improves calibration accuracy without requiring external calibration equipment or complex manual procedures, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical calibration procedures with an automated sensor-based detection system. The sensor automatically detects positions and the system automatically calculates transformations, substituting complex manual mechanical adjustment with simpler automated computational processes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

The solution increases the accuracy of input device calibration to within 300 microns, providing enhanced control and operation of the computing device by accurately determining the input device's location and adjusting settings accordingly.

Implementation Method 1

The input device may use a sensor to detect its position relative to a position-encoded film of a display and a pixel array of the display

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Data Source

PatentEP3250992B1Calibration of an input device to a display using the input device
Publication Date: 2021.08.25 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3250992B1 patent drawingFigure 1
  • EP3250992B1 patent drawingFigure 2
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AI summary

Examples disclosed herein involve calibrating an input device to a display using the input device. An example method includes determining first coordinates of a position-encoded film corresponding to a location of an input device relative to the position-encoded film of a display of a computing device based on first position points of the position-encoded film, determining second coordinates of a pixel array corresponding to the location of the input device relative to the pixel array of the display based on a first reference pixel of the display, measuring a first offset between the first coordinates of the position-encoded film and the second coordinates of the pixel array, and calculating a calibration transformation to control the computing device based on the first offset.