Image Forming Apparatus Circumference Measurement Using Toner Waveforms

Solution Overview

Problem

Conventional image forming apparatuses using the electrophotographic method face challenges in accurately measuring the circumference of rotation members, leading to errors in positioning and increased downtime and costs, particularly due to the need for optical detection marks and sensors, as well as excessive toner consumption during circumference measurement.

Innovation Solution

An image forming apparatus that acquires first and second waveform data from a rotation member using a detector and calculates the circumference based on matching between these data sets, allowing for precise density detection and reduced downtime without the need for optical detection marks or sensors, thereby minimizing toner usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an optical detection mark and optical sensor are used to measure the circumference of the rotation member, then the circumference measurement can be performed, but the device complexity increases and the cost increases

Engineering Contradiction:

Improvecircumference measurement accuracyVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The image carrier itself serves as the measurement target by utilizing its inherent image formation function. The detector reads toner images formed on the image carrier to obtain waveform data, eliminating the need for separate optical detection marks and dedicated circumference measurement sensors. The system uses the image carrier's own characteristics (toner adhesion patterns) to provide measurement information.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The detector serves dual purposes: it both forms/detects toner images for image density calibration and measures the circumference of the image carrier through waveform data analysis. This multi-functionality eliminates the need for separate dedicated measurement components, reducing device complexity while maintaining measurement capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If an optical detection mark and optical sensor are used to measure the circumference of the rotation member, then the circumference measurement can be performed, but the cost increases

Engineering Contradiction:

Improvecircumference measurement accuracyVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The image carrier itself serves as the measurement target by utilizing its inherent image formation function. The detector reads toner images formed on the image carrier to obtain waveform data, eliminating the need for separate optical detection marks and dedicated circumference measurement sensors. The system uses the image carrier's own characteristics (toner adhesion patterns) to provide measurement information.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The detector serves dual purposes: it both forms/detects toner images for image density calibration and measures the circumference of the image carrier through waveform data analysis. This multi-functionality eliminates the need for separate dedicated measurement components, reducing device complexity while maintaining measurement capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Measurement precision

If the image carrier rotates multiple rounds to position the mark under the optical sensor for circumference measurement, then the circumference can be measured, but the measurement time increases and productivity decreases

Engineering Contradiction:

Improvecircumference measurement accuracyVSAvoidmeasurement speed

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

Toner images are formed on the image carrier in advance at multiple positions during the normal image formation process. When circumference measurement is needed, the detector simply reads these pre-formed images as the image carrier rotates, eliminating the need to wait for specific mark positioning. The measurement can begin immediately without requiring multiple rotation cycles for mark alignment.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The image carrier continues to rotate continuously for its normal function (image formation and transfer) while the detector simultaneously performs circumference measurement by reading toner images at appropriate positions. This eliminates idle rotation time specifically for measurement purposes, as the measurement occurs during the normal operational rotation of the image carrier.

Inventive Principle:

Principle #20Continuity of useful action

4Measurement precision

If a patch is formed for circumference measurement in a direct transfer method, then the circumference can be measured, but the toner consumption increases

Engineering Contradiction:

Improvecircumference measurement accuracyVSAvoidtoner consumption

Core Design Contradiction:

Measurement precisionVSLoss of substance

Solution Approach 1:

The circumference measurement function is merged with the normal image formation process. Toner images formed for regular printing operations are simultaneously used as the measurement target by the detector. This eliminates the need to form separate dedicated measurement patches, as the functional images serve dual purposes: image formation and circumference measurement reference.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The detector serves dual purposes: it both forms/detects toner images for image density calibration and measures the circumference of the image carrier through waveform data analysis. This multi-functionality eliminates the need for separate dedicated measurement components, reducing device complexity while maintaining measurement capability.

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 approach enables faster and more accurate circumference measurement, reducing downtime and toner consumption while maintaining precision, thus enhancing the usability and cost-effectiveness of the image forming apparatus.

Implementation Method 1

a detector that detects light coming from the rotation member

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS8565627B2Image forming apparatus and control method thereof

Publication Date: 2013.10.22 CANON KK

AI summary

There is provided an image forming apparatus which shortens the time taken for circumference detection and measures the circumference at high precision without obstructing downsizing of the apparatus. To accomplish this, the image forming apparatus detects, at an arbitrary timing, the physical pattern of the image-formed surface of a rotation member that changes over time. In the second round, the image forming apparatus detects the second pattern at a timing a predetermined time after the arbitrary timing. By using the detected patterns, the image forming apparatus obtains information associated with the circumference of the rotation member.