Toner Amount Calculation Using Spatial Filters for Edge Effects
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Solution Overview
Problem
Existing image forming apparatuses face errors in calculating toner consumption due to the 'edge effect' and non-linear relationships between exposure signals and gradation levels, leading to inaccuracies in toner amount calculation.
Innovation Solution
The apparatus includes a toner amount calculating unit that determines a base toner amount and an edge emphasis amount using spatial filters, with a limiter processing unit to correct and control the edge emphasis, ensuring accurate toner consumption calculation by accounting for both laser profiles and edge effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a toner consumption amount is calculated on the basis of an exposure signal with taking the edge effect into account, then the edge effect is considered, but an error may appear in the calculated toner consumption amount due to non-linear characteristic
Solution Approach 1:
The patent segments the toner consumption calculation into two distinct parts: base toner consumption (from exposure signal) and edge effect toner consumption (from edge detection). By calculating these separately and then summing them, the patent avoids the error that occurs when trying to calculate total consumption directly from the non-linear exposure signal while accounting for edge effects.
Solution Approach 2:
The patent extracts the edge effect component from the overall toner consumption calculation. It specifically identifies and separates the additional toner consumption at boundaries between dots and non-dots, calculating this edge effect consumption independently based on the number of edges detected in the image data, rather than relying on the non-linear exposure signal.
2Measurement precision
If gradation correction process is performed to correct image data values, then the relationship between image data and gradation levels gets closer to linear, but the relationship between exposure intensities and gradation levels becomes non-linear
Solution Approach 1:
The patent extracts the edge effect calculation from the gradation correction process. It calculates the number of edges in the image data independently of the gradation correction, then uses this edge count to determine edge effect toner consumption separately, avoiding the complexity of trying to maintain linear relationships through gradation correction.
Solution Approach 2:
The patent uses a simplified model that copies the essential characteristic (number of edges) from the image data to calculate edge effect consumption, rather than attempting to replicate the complex non-linear relationship between exposure intensities and gradation levels. This copying approach maintains accuracy while reducing calculation complexity.
Data Source
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AI summary
A base toner amount determining unit is configured to determine a base toner amount without taking edge effect into account, the base toner amount corresponding to a pixel value of image data for which gradation correction has not been performed. A laser profile applying unit is configured to perform for the base toner amount a first spatial filter process corresponding to a laser profile of an exposure device. An edge emphasis amount determining unit is configured to perform a second spatial filter process for the base toner amount before the first spatial filter process or after the first spatial filter process and thereby determine an edge emphasis amount correspond to the edge effect. A toner counter is configured to count as a toner consumption amount a sum of the base toner amount after the first spatial filter process and the edge emphasis amount.