LED Exposure Chip Control for Magnification Error Compensation
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Solution Overview
Problem
Existing image forming apparatuses using electrophotographic systems face issues with image quality deterioration due to uneven compensation for magnification errors, which can occur from variations in the mounting position of light-emitting chips and thermal expansion, leading to visually recognizable discrepancies.
Innovation Solution
The exposure apparatus employs a light-emitting chip with a plurality of rows and columns, divided into blocks, where each light-emitting element is controlled by a drive circuit to form electrostatic latent images with adjustable spot formation and data insertion/thinning to correct image width and position, excluding elements at block ends.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If data insertion or thinning-out is performed to compensate for magnification error, then image width correction is achieved, but unevenness due to compensation becomes visually recognizable depending on insertion/thinning position
Solution Approach 1:
The light-emitting element array is divided into multiple blocks along the row direction, with each block independently controllable. Data insertion or thinning-out is performed selectively within specific blocks rather than uniformly across the entire array, allowing magnification error compensation to be distributed and blended across block boundaries, thereby reducing visually recognizable unevenness.
Solution Approach 2:
Different regions of the light-emitting element array are treated differently based on their position. The patent selectively performs data insertion or thinning-out in certain blocks while maintaining original data in other blocks, creating local variations in data density that compensate for magnification errors while minimizing visible artifacts through strategic placement of compensation regions.
2Adaptability or versatility
If light-emitting elements at block ends are used for data insertion/thinning, then flexibility in compensation is increased, but light emission unevenness occurs at block boundaries
Solution Approach 1:
Light-emitting elements at the end columns of each block are excluded from participating in data insertion or thinning-out operations. This extraction of boundary elements prevents them from creating light emission unevenness at block boundaries, while interior elements within each block perform the compensation function, maintaining both flexibility and uniformity.
3Measurement precision
If the number of light-emitting elements forming each spot is changed for magnification correction, then image width accuracy is improved, but positions of other spots must be shifted causing alignment complexity
Solution Approach 1:
The image formation process is segmented into multiple blocks, with spot position shifts and light-emitting element count changes confined to specific blocks. This segmentation allows independent control of compensation parameters in each block, reducing the overall complexity of coordinating spot positions across the entire image while maintaining accurate magnification correction.
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 effectively suppresses image quality deterioration by accurately compensating for magnification errors, ensuring consistent image formation across the photoconductive body.
Implementation Method 1
a light-emitting chip including a plurality of light-emitting elements that constitute a plurality of rows and a plurality of columns
Implementation Method 2
control the plurality of light-emitting elements so as to form, on the photoconductive body, an electrostatic latent image that is for forming an image
Data Source
AI summary
An exposure apparatus including a light-emitting chip including light-emitting elements and a controller is provided. The light-emitting elements are divided into blocks. The controller controls the light-emitting elements so as to form an electrostatic latent image that is constituted by spots and each of the spots is formed by a predetermined number of light-emitting elements, and changes the number of light-emitting elements that form a spot from the predetermined number in accordance with correction data for correcting a width of the image in the axial direction, and shifts, in accordance with a change in the number of light-emitting elements that form the spot, positions of some of other spots. The spot is formed by using a light-emitting element excluding light-emitting elements provided on columns at two ends of each block.