Scanner Light Adjustment via Black Reference Compensation
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Solution Overview
Problem
Conventional image scanning apparatuses require a long period for light amount adjustment due to variations in black levels among sensor chips, necessitating multiple scanning operations to calculate the target light amount value.
Innovation Solution
An improved image scanning apparatus with a controller that calculates compensation data to adjust light levels by scanning a reference member with the light source off, allowing for real-time adjustment of light emission based on digital data and black reference data, enabling faster light amount adjustment without the need for multiple scanning operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple scanning operations are performed to calculate target light amount value, then light amount adjustment accuracy is improved, but light amount adjustment time increases
Solution Approach 1:
The patent performs preliminary action by obtaining black reference data when the light source is turned off before actual scanning. This pre-acquired reference data is then used during light amount adjustment calculations, eliminating the need for multiple scanning operations with different light amounts. The controller calculates compensation data using the pre-obtained black reference data and digital data from a single scan, thereby reducing adjustment time while maintaining accuracy.
2Stability of the object's composition
If black level variations among sensor chips are compensated, then image quality uniformity is improved, but scanning operation complexity increases
Solution Approach 1:
The patent introduces black reference data as an intermediary element to compensate for black level variations. Instead of directly adjusting each sensor chip's output, the system obtains black reference data when the light source is off, calculates compensation data by comparing digital data with this reference, and uses the compensation data to adjust light amount settings. This intermediary approach simplifies the overall operation while achieving uniform image quality.
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 apparatus can execute light amount adjustment quickly, even with variations in black levels, by using compensation data to set the optimal light emission value, reducing the overall time required for light adjustment.
Implementation Method 1
a light source and a light receiver configured receive reflected light which is light emitted by the light source and reflected by the original sheet
Implementation Method 2
a light receiver configured receive reflected light which is light emitted by the light source and reflected by the original sheet
Data Source
AI summary
In a scanning apparatus, a controller is configured to obtain black reference data, compensated data based on digital data (scan data) by scanning a reference member with the light source turned off, and the black reference data. The controller further compares the compensated data with a first particular value. The controller executes the compensated data obtaining process with setting the light amount adjustment value to be a smaller value when the compensated data is greater than the first particular value, while with setting the light amount adjustment value to be a greater value when the compensated data is less than the first particular value. Further, the controller sets the light amount adjustment value to be a scan-time light amount adjustment value when the light amount adjustment value is equal to the first particular value. Then, the controller executes a scanning process according to the scan-time light amount adjustment value.