Optical Scanning Head Light Intensity Correction for LED Arrays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical scanning heads for image processing apparatuses face challenges in maintaining consistent light intensity across light-emitting elements due to variations in wiring lengths, leading to uneven light emission and image quality issues.
Innovation Solution
An optical scanning head with plural light-emitting element arrays, a light-emitting control unit, and a correction unit that uses a storage unit to store and apply correction values for light intensity variations, allowing for timely adjustments in light-emitting timing signals to ensure consistent light emission across all elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If light-emitting elements are arranged in arrays along the scanning direction, then the image processing capability is improved, but light intensity variation occurs due to arrival time differences of signals
Solution Approach 1:
The patent applies preliminary action by storing correction values in advance in a storage unit (ROM or RAM) that compensates for light intensity variations. These correction values are prepared beforehand based on the known wiring length differences and signal arrival time variations, allowing the system to pre-correct the light emission timing without real-time calculation delays.
Solution Approach 2:
The patent changes the timing parameter of light emission by adding correction values to the light-emitting timing signals. This parameter adjustment compensates for the arrival time differences caused by varying wiring lengths, ensuring that all light-emitting elements emit light with consistent intensity despite their different positions in the array.
2Area of stationary object
If wiring lengths to light-emitting elements are varied due to array arrangement, then the device coverage is improved, but light intensity consistency deteriorates
Solution Approach 1:
The patent applies local quality by providing individual correction values for each light-emitting element or group of elements. The storage unit contains specific correction data tailored to the local wiring length characteristics of different regions in the array, allowing each local area to be corrected according to its specific signal arrival time differences.
Solution Approach 2:
The patent adjusts the timing parameter of light emission locally for different elements by adding specific correction values. This parameter change compensates for the local wiring length variations, ensuring that elements at different positions (with different wiring lengths) all emit light with consistent intensity.
3Device complexity
If correction values are stored in a common storage unit, then the device complexity is reduced, but the correction precision for different element groups may be compromised
Solution Approach 1:
The patent applies universality by using a single common storage unit that serves all light-emitting element arrays. This storage unit stores correction values for multiple elements or groups of elements, allowing one component to perform the correction function for the entire array without requiring separate storage units for each element.
Solution Approach 2:
The patent segments the correction data into different correction values for different light-emitting elements or groups of elements, all stored within the common storage unit. This segmentation allows precise correction for each element while maintaining a unified storage structure, balancing precision requirements with device simplicity.
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 effectively corrects light intensity variations, enhancing image quality by ensuring uniform light emission and reducing defects in the printed images.
Implementation Method 1
An image processing apparatus that uses, as the optical recording unit, an LED print head (LPH) in which plural light-emitting elements (for example, plural light-emitting diodes (LEDs)) are arranged
Data Source
AI summary
Provided is an optical scanning head including plural light-emitting element arrays that are arranged along a scanning direction, each of which includes plural light-emitting elements, a light-emitting control unit that outputs a light-emitting timing signal generated based on image information to each light-emitting element of the plural light-emitting element arrays to control light emission of the light-emitting element, a storage unit that is common to the plural light-emitting element arrays and stores a correction value of a light intensity variation due to an arrival time difference between the light-emitting timing signals to the plural light-emitting elements, and a correction unit that corrects the light-emitting timing signal based on the correction value.