Printed Vernier Scale for Skew Correction

Solution Overview

Problem

Existing imaging devices face challenges in correcting skew errors in print media without introducing costly mechanical components or optical sensors, which can complicate the printer design and increase costs.

Innovation Solution

The implementation of a vernier scale printed on the print medium, which allows for the determination of skew correction values by folding the medium and measuring the overlap of the scales, eliminating the need for complex mechanical correction mechanisms or optical sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If mechanical correction mechanisms or optical sensors are used to correct skew errors, then skew correction capability is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improveskew correction capabilityVSAvoidmechanical components and optical sensors

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses a printed vernier scale copy on the print medium itself to determine skew correction values, replacing the need for complex mechanical correction mechanisms or optical sensors. The vernier scale is printed directly on the print medium and can be measured with simple tools, eliminating the need for expensive and complex skew detection hardware.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent employs a disposable printed vernier scale on the print medium that can be easily manufactured and discarded, replacing expensive, complex mechanical components and optical sensors. The vernier scale is printed using standard printing mechanisms and requires no specialized hardware, significantly reducing device complexity and manufacturing cost.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Measurement precision

If mechanical correction mechanisms are added to correct skew errors, then skew correction capability is improved, but manufacturing cost increases

Engineering Contradiction:

Improveskew correction capabilityVSAvoidproduction cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent uses a printed vernier scale copy on the print medium itself to determine skew correction values, replacing the need for complex mechanical correction mechanisms or optical sensors. The vernier scale is printed directly on the print medium and can be measured with simple tools, eliminating the need for expensive and complex skew detection hardware.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent employs a disposable printed vernier scale on the print medium that can be easily manufactured and discarded, replacing expensive, complex mechanical components and optical sensors. The vernier scale is printed using standard printing mechanisms and requires no specialized hardware, significantly reducing device complexity and manufacturing cost.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If optical sensors are used to detect skew errors, then skew correction capability is improved, but device complexity increases

Engineering Contradiction:

Improveskew detection accuracyVSAvoidoptical sensors and associated mechanisms

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses a printed vernier scale copy on the print medium itself to determine skew correction values, replacing the need for complex mechanical correction mechanisms or optical sensors. The vernier scale is printed directly on the print medium and can be measured with simple tools, eliminating the need for expensive and complex skew detection hardware.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent replaces optical sensing mechanisms with a mechanical measurement approach using a printed vernier scale that can be measured with simple physical tools. This substitution eliminates the need for complex optical sensors and associated electronic systems, reducing device complexity while maintaining skew detection capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3997022B1Print indicia for skew correction

Publication Date: 2025.04.02 HEWLETT PACKARD DEVELOPMENT COMPANY LP

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Figure 3A~3B

AI summary

According to examples, an apparatus may include a processor and a memory on which are stored machine-readable instructions that when executed by the processor, may cause the processor to print a first indicia at a first region on a first side of a print medium. The instructions may also cause the processor to print a second indicia at a second region on the first side of the print medium, in which the second region may be spaced a prescribed distance from the first region along a first edge of the print medium. In some examples, a relative position of the first indicia to the second indicia may correlate to a skew correction value for the first edge of the print medium.