Optical Tracking Light Diffuser for Stray Light Control

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Solution Overview

Problem

Existing optical tracking devices have complex mechanical designs and high manufacturing costs due to complicated casing mechanisms and high-precision assembly requirements, leading to increased production costs and reduced product competitiveness.

Innovation Solution

An optical tracking device with a light diffuser comprising a diffusion film and a light shielding layer, which includes a transparent pattern, is used to block stray light and reorganize the light path, enhancing sharpness and accuracy while simplifying the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If surface-treated casing mechanisms or optical lenses combined with point light sources are used, then light emission quality and stability are improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvelight emission stabilityVSAvoidcasing mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the light shielding function from the complex casing mechanism and integrates it directly into the diffusion film through a light shielding layer. This separation of functions simplifies the overall structure by eliminating the need for separate casing mechanisms while maintaining light emission stability through the combined diffusion and shielding properties of the film.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges multiple functions into a single component: the diffusion film simultaneously provides light diffusion, light shielding (through the integrated light shielding layer), and structural support. This consolidation eliminates the need for separate optical lenses and complex casing mechanisms, reducing device complexity while maintaining reliability.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If high-precision assembly and alignment of optical elements are implemented, then optical tracking accuracy is improved, but manufacturing cost and production time increase

Engineering Contradiction:
Improvetracking accuracyVSAvoidproduction efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent segments the optical system into modular components (diffusion film, light shielding layer, transparent pattern) that can be independently manufactured and then easily assembled. This segmentation allows for standardization of components, reducing the need for high-precision custom assembly while maintaining tracking accuracy through the designed optical paths.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses a transparent pattern on the diffusion film that acts as a template or copy of the desired light emission geometry. This pattern can be mass-produced using printing or adhesive processes, eliminating the need for high-precision manual alignment while ensuring consistent optical performance across production batches.

Inventive Principle:
Principle #26Copying

3Manufacturing precision

If complex manufacturing processes are used, then product quality is improved, but production cost increases

Engineering Contradiction:
Improveoptical element qualityVSAvoidmanufacturing simplicity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent changes the manufacturing approach from precision mechanical fabrication to material property-based solutions. By utilizing the optical properties of the diffusion film and light shielding layer (transparency, diffusion coefficient, absorption characteristics), the system achieves high manufacturing precision through material selection rather than complex processing, enabling easier and more cost-effective production.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces expensive, durable optical lenses and precision-machined optical elements with more economical diffusion films and light shielding layers. These materials can be produced through simpler, lower-cost processes (printing, adhesive application) while achieving the required optical performance, thereby reducing manufacturing costs without sacrificing quality.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Measurement precision

If light shielding structures are added to block stray light, then sensing accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvesensing accuracyVSAvoidoptical structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The light shielding layer integrated into the diffusion film serves multiple functions simultaneously: it shields stray light, maintains the structural integrity of the optical assembly, and works in conjunction with the transparent pattern to define the emission geometry. This multi-functionality eliminates the need for separate light shielding structures, reducing device complexity while improving sensing accuracy.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 reduces production costs and improves yield by eliminating stray light interference, increasing sensing stability and accuracy, and allowing for low-cost mass production.

Implementation Method 1

The diffusion film overlaps the sensing light source... The diffusion effect of the diffusion film on the sensing light is equivalent to changing the shape of a point light source of the sensing light source into the shape of a light spot of the transparent pattern

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

The light shielding layer of the light diffuser can provide a light shielding effect, which can block unexpected light exit regions and absorb stray light, further enhancing the sharpness of the sensing light

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 3

The light shielding layer is disposed on the diffusion film and includes a transparent pattern. The transparent pattern overlaps the sensing light source

Methodology Applied
Scientific EffectLight transmission: Reflection

Data Source

PatentEP4679165A1Optical tracking device
Publication Date: 2026.01.14 HTC CORP
  • EP4679165A1 patent drawingFigure 1
  • EP4679165A1 patent drawingFigure 2
  • EP4679165A1 patent drawingFigure 3A~3C

AI summary

An optical tracking device includes a circuit substrate, a sensing light source, and a light diffuser. The sensing light source is electrically connected to the circuit substrate and configured to emit sensing light. The sensing light source is disposed between the light diffuser and the circuit substrate. The light diffuser includes a diffusion film and a light shielding layer. The diffusion film overlaps the sensing light source. The light shielding layer is disposed on the diffusion film and includes a transparent pattern. The transparent pattern overlaps the sensing light source.