Horizontal CIS Sensor for Stacker Tray Position Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current paper handling systems in electrostatic marking systems lack a reliable, inexpensive, and real-time method to continuously measure the position and direction of the elevator supporting the paper stack, relying on complex and costly sensor systems that require homing operations and multiple sensors to determine elevator location and motion accurately.

Innovation Solution

A small Contact Image Sensor (CIS) is mounted horizontally to detect a continuously variable slanted shape marker, such as a triangular decal, allowing for accurate and instantaneous elevator positional data without the need for homing operations and reducing sensor size and complexity by using a marker that provides measurable changes in shape, color, or pixel intensity as the sensor moves vertically.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple transmissive sensors and comb brackets are used to detect elevator position, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improveelevator position detection accuracyVSAvoidsensor array complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the position detection function from complex multi-sensor systems and implements it using a single linear encoder. The encoder strip is mounted on the elevator carrier, and a single read head detects position through optical encoding, eliminating the need for multiple discrete sensors and comb brackets while maintaining measurement precision.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses an optical encoding system where the linear encoder strip contains patterned information that is optically copied and read by the encoder read head. This optical copying mechanism allows precise position detection without requiring physical contact or complex mechanical sensor arrays.

Inventive Principle:

Principle #26Copying

2Device complexity

If encoder-style point sensors with transition detection are used, then device complexity is reduced, but measurement precision and real-time location capability deteriorate

Engineering Contradiction:

Improvesensor system simplicityVSAvoidreal-time elevator location accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces mechanical transition-based point sensor detection with an optical encoding system. The linear encoder uses optical patterns on a strip that provide continuous position information, eliminating the need for mechanical homing operations and transition counting while improving real-time location accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If homing operations are implemented to ensure encoder count accuracy, then measurement precision is improved, but productivity decreases due to time loss

Engineering Contradiction:

Improveencoder count accuracyVSAvoidstacker operation efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The linear encoder system is pre-configured with a reference mark or index pattern on the encoder strip that allows the read head to immediately establish absolute position upon power-up or after any interruption. This preliminary positioning capability eliminates the need for homing operations while maintaining encoder count accuracy throughout operation.

Inventive Principle:

Principle #10Preliminary action

4Reliability

If additional sensors are added to detect upper and lower limits, then reliability is improved, but device complexity increases

Engineering Contradiction:

Improveelevator position limit detectionVSAvoidsensor quantity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The linear encoder system serves multiple functions simultaneously: it provides continuous position measurement, detects upper and lower travel limits through the encoder strip patterns, and enables real-time motion detection. This multi-functionality eliminates the need for separate limit sensors while improving reliability through integrated detection.

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

This solution enables accurate and real-time elevator position and motion detection without the need for extensive sensor arrays, reducing costs and complexity while maintaining high accuracy, allowing for efficient operation without the requirement for homing operations.

Implementation Method 1

A small sensor array such as a CIS (contact Image Sensor) horizontally along with a continuously variable slanted shape such as a triangle, the system can provide both accurate and instantaneous elevator positional data

Methodology Applied

Scientific EffectOptical projection and perspective geometry: Geometry

Data Source

PatentUS8585046B2Horizontal sensor and variable pattern for detecting vertical stacker position

Publication Date: 2013.11.19 XEROX CORP

AI summary

This invention provides an effective and inexpensive stacker tray assembly apparatus and method for determining an elevator stacker tray location in the assembly. A sensor is attached to the stacker tray so that it is in sensing proximity to a continuous variable slanted shape marker. The marker has measurables therein where the measurables decrease in measurement as they proceed from a bottom of the marker to an upper portion of the marker. The sensor is substantially shorter than a length of the movable elevator stacker tray travel.