Dot Code Pattern for Optical Pen Position Tracking

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Solution Overview

Problem

Existing methods for archiving handwritten documents using optical pens face challenges such as high dot density patterns that are difficult to print and read, noise susceptibility, alignment issues, and the need for mechanical pen contact detection, which complicates real-time position determination and document editing.

Innovation Solution

A printable dot code pattern and process that encodes spatial information on a surface, allowing an optical pen to read the pattern while printing a document, with features like narrow parallel bands and invisible ink to maintain document readability and enable real-time position tracking without mechanical contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a high dot density pattern is used to improve position precision, then measurement precision is improved, but image analysis difficulty increases and processing time increases

Engineering Contradiction:
Improveposition determination precisionVSAvoidimage analysis difficulty
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The dot pattern is segmented into multiple functional zones: a first plurality of dots arranged in a grid pattern for position determination, and a second plurality of dots arranged in alphanumeric patterns for character encoding. This segmentation allows each zone to be optimized independently - the grid dots provide precise position data while the alphanumeric dots provide readable character data, reducing overall analysis complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the position determination function from the character encoding function by using two separate dot patterns. The grid pattern exclusively handles position data while the alphanumeric pattern handles character data, allowing the image analysis system to process position and character information through separate, optimized pathways rather than analyzing a single complex combined pattern

Inventive Principle:
Principle #2Taking out (Extraction)

2Area of stationary object

If small dots are used to increase dot density, then area coverage is improved, but noise susceptibility increases

Engineering Contradiction:
Improvepattern area coverageVSAvoidnoise susceptibility
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

Different dot sizes are used for different functions within the same pattern. The grid dots are larger (reducing noise susceptibility for position data) while the alphanumeric dots can be smaller (allowing higher density for character encoding). This local differentiation of dot quality optimizes each function's performance characteristics

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The dot pattern uses composite structures combining multiple dot sizes and arrangements within a single pattern. The larger grid dots provide robust position information resistant to noise, while smaller alphanumeric dots provide compact character encoding, creating a composite pattern that leverages the advantages of both dot size regimes

Inventive Principle:
Principle #40Composite materials

3Ease of operation

If dots are printed separately from the document, then pattern readability is improved, but alignment accuracy deteriorates

Engineering Contradiction:
Improvepattern readabilityVSAvoidalignment accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The dot pattern and document content are merged into a single printing operation. The pattern includes both visible document content and invisible or subtly visible dot markers that are printed simultaneously on the same substrate, ensuring perfect alignment between the document and the tracking pattern while maintaining readability through the use of invisible ink or patterns that blend with the document background

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses an intermediary printing layer containing the dot pattern that is applied over or with the document. This intermediary layer contains alignment markers and dot patterns that facilitate tracking without obscuring the underlying document content, acting as a mediator between the document and the optical tracking system

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of manufacture

If even distribution of dots is used to simplify pattern design, then manufacturing complexity is reduced, but position precision deteriorates

Engineering Contradiction:
Improvepattern design simplicityVSAvoidposition determination precision
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The dot pattern employs asymmetric arrangements where grid dots are positioned at non-uniform intervals or with varying orientations to encode position information more precisely. The alphanumeric dots are also asymmetrically arranged to represent characters. This asymmetry increases the information content per dot while maintaining manufacturability through standard printing processes

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2591441B1Dot code pattern for absolute position and other information using an optical pen, process of printing the dot code, process of reading the dot code
Publication Date: 2019.11.06 REZENDE MARCELO AMARAL
  • EP2591441B1 patent drawingFigure 1~2
  • EP2591441B1 patent drawingFigure 3~4
  • EP2591441B1 patent drawingFigure 5~6B

AI summary

A manufacture for encoding information from which a position of an optical pen tip can be derived, said manufacture includes a display medium having a supporting base and upon which is encoded a two dimensional code pattern that is continuously arranged on an entire surface of the supporting base; wherein the pattern is formed by a sequence of narrow parallel bands, including at least two parallel lines, of which one line is a base line the remaining lines are secondary lines; wherein each narrow parallel band includes a sequence of dots, the dots being arranged in a pre-determined position in order to represent a number at a selected number base.