Hydroxygallium Phthalocyanine Crystal Sensitivity Uniformity

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Solution Overview

Problem

Electrophotographic photosensitive members experience sensitivity unevenness due to thickness unevenness, which is not effectively addressed by existing hydroxygallium phthalocyanine and oxytitanium phthalocyanine crystals.

Innovation Solution

A novel hydroxygallium phthalocyanine crystal with specific X-ray diffraction peaks is developed by adding an amide compound and undergoing milling treatment, resulting in a photosensitive layer with improved sensitivity uniformity, linearly dependent on electric field intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If existing hydroxygallium phthalocyanine or oxytitanium phthalocyanine crystals are used, then high sensitivity to long wavelength light is achieved, but sensitivity unevenness occurs due to thickness unevenness

Engineering Contradiction:

Improvelight sensitivityVSAvoidsensitivity uniformity

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The invention changes the crystal structure parameters of hydroxygallium phthalocyanine by controlling the milling treatment conditions and amide compound addition, transforming it from a non-linear photoelectric conversion material to one with linear photoelectric conversion characteristics, thereby resolving the sensitivity unevenness problem while maintaining high light sensitivity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite system by combining hydroxygallium phthalocyanine crystals with specific crystal forms (obtained through milling treatment) with amide compounds, forming a photosensitive layer that exhibits both high sensitivity and uniform response characteristics, effectively addressing the sensitivity unevenness issue

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If the photosensitive layer thickness is increased to improve sensitivity, then light absorption is enhanced, but sensitivity unevenness due to thickness variation is worsened

Engineering Contradiction:

Improvelight absorption efficiencyVSAvoidthickness uniformity

Core Design Contradiction:

Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

By changing the photoelectric conversion characteristics through crystal form modification, the invention enables the photosensitive layer to maintain linear response even with thickness variations, allowing for improved light absorption without proportionally increasing sensitivity unevenness

Inventive Principle:

Principle #35Parameter changes

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 suppresses sensitivity unevenness caused by thickness variations, enhancing the photoelectric conversion efficiency and stability of the electrophotographic photosensitive member.

Implementation Method 1

the photosensitive layer contains a hydroxygallium phthalocyanine crystal having peaks at Bragg angles 2θ±0.2° of 6.9°, 7.7°, 16.4°, 24.4°, and 26.5° in CuKα X-ray diffraction

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Implementation Method 2

by adding an amide compound and a hydroxygallium phthalocyanine and performing a milling treatment

Methodology Applied

Scientific EffectMilling treatment: Abrasion

Data Source

PatentUS9519232B2Electrophotographic photosensitive member, method for producing electrophotographic photosensitive member, process cartridge and electrophotographic apparatus, and hydroxygallium phthalocyanine crystal

Publication Date: 2016.12.13 CANON KK

AI summary

An electrophotographic photosensitive member includes a support and a photosensitive layer on the support, and the photosensitive layer contains a hydroxygallium phthalocyanine crystal having peaks at Bragg angles 2θ±0.2° of 6.9°, 7.7°, 16.4°, 24.4°, and 26.5° in CuKα X-ray diffraction.