Density Detection Sensor Placement in Image Forming Apparatus
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Solution Overview
Problem
Image forming apparatuses face challenges in reducing the number of density detection parts without compromising density fluctuation correction accuracy, especially when dealing with multiple light-emitting parts, which increases costs and complexity.
Innovation Solution
The apparatus employs plural light-emitting parts with density detection sensors positioned at central and end portions of the image carrier to detect image density, allowing for reduced sensor numbers while maintaining accuracy through strategic placement and use of different sensor performance levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If equal numbers of density detection parts are provided for each light-emitting part, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent applies local quality by differentiating the functional requirements of different detection positions. Central positions use density detection parts to monitor overall density, while end portions use reflection type density detection parts specifically for edge density correction. This localized differentiation allows reducing the total number of sensors while maintaining correction accuracy where most needed.
Solution Approach 2:
The patent segments the detection function into two distinct types: density detection parts for central regions and reflection type density detection parts for end portions. This segmentation allows each sensor type to be optimized for its specific location's requirements, reducing the overall sensor count while maintaining comprehensive coverage.
2Measurement precision
If equal numbers of density detection parts are provided for each light-emitting part, then measurement precision is improved, but cost increases
Solution Approach 1:
The patent applies local quality by differentiating the functional requirements of different detection positions. Central positions use density detection parts to monitor overall density, while end portions use reflection type density detection parts specifically for edge density correction. This localized differentiation allows reducing the total number of sensors while maintaining correction accuracy where most needed.
Solution Approach 2:
The patent implements partial action by providing density detection parts for only three positions (central and two end portions) rather than for every light-emitting part. This partial coverage is sufficient to capture the essential density variations needed for correction, reducing the quantity of detection parts while maintaining adequate measurement precision.
3Device complexity
If density detection parts are positioned at central and end portions only, then device complexity is reduced, but measurement precision may deteriorate
Solution Approach 1:
The patent applies local quality by differentiating the functional requirements of different detection positions. Central positions use density detection parts to monitor overall density, while end portions use reflection type density detection parts specifically for edge density correction. This localized differentiation allows reducing the total number of sensors while maintaining correction accuracy where most needed.
Solution Approach 2:
The control unit acts as an intermediary that processes density information from the strategically positioned sensors and generates appropriate correction data. It synthesizes the density values from central and end portion detections to create comprehensive correction patterns, maintaining measurement precision despite reduced sensor quantity through intelligent data processing.
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 configuration effectively reduces the number of density detection parts required, minimizing costs while maintaining accurate density fluctuation correction across the image forming process, even with multiple light-emitting parts.
Implementation Method 1
an exposure part having plural light-emitting parts that are shifted from one another so as to face the image carrier and in each of which plural light-emitting elements are aligned and forms an electrostatic latent image on the image carrier by exposing the image carrier to light
Implementation Method 2
plural density detection parts that are disposed at positions corresponding to substantially central positions of the plural light-emitting parts and at positions corresponding to end portions closer to end portions of the image carrier among end portions of two light-emitting parts disposed close to the end portions of the image carrier among the plural light-emitting parts and detect a density of an image obtained by developing the electrostatic latent image on the image carrier
Data Source
AI summary
An image forming apparatus includes: an image carrier that carries an image developed by a developer; an exposure part that has plural light-emitting parts that are shifted from one another so as to face the image carrier and in each of which plural light-emitting elements are aligned and forms an electrostatic latent image on the image carrier by exposing the image carrier to light; and plural density detection parts that are disposed at positions corresponding to substantially central positions of the plural light-emitting parts and at positions corresponding to end portions closer to end portions of the image carrier among end portions of two light-emitting parts disposed close to the end portions of the image carrier among the plural light-emitting parts and detect a density of an image obtained by developing the electrostatic latent image on the image carrier.