Heating Member Temperature Detection Using Dual Amplification Factors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image forming apparatuses face inaccuracies in determining the temperature of heating members due to quantization errors during analog-to-digital conversion, which can affect the proper fixation of toner images on sheets.
Innovation Solution
The apparatus employs a temperature sensor with a detection thermistor and a compensation thermistor, along with differential amplifiers and an ADC, to generate temperature information with varying amplification factors, allowing for accurate temperature determination within specific ranges by reducing quantization errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single amplification factor is used in the conversion circuit, then the device complexity is reduced, but the temperature measurement precision deteriorates due to quantization errors
Solution Approach 1:
The temperature detection range is segmented into multiple ranges, with different amplification factors applied to different segments. The conversion circuit includes a first amplifier with a first amplification factor for a first temperature range and a second amplifier with a second amplification factor for a second temperature range, dividing the detection task into segments to maintain precision across the full range while managing complexity.
Solution Approach 2:
The amplification factor is made dynamic rather than fixed, allowing the circuit to switch between different amplification factors based on the detected temperature range. This dynamic adjustment optimizes measurement precision for different temperature conditions while keeping the overall device design manageable through controlled complexity.
2Measurement precision
If a higher amplification factor is used, then the temperature measurement precision is improved, but the device complexity increases due to multiple amplifiers
Solution Approach 1:
The temperature detection system is segmented into multiple ranges, each handled by a dedicated amplifier with an optimized amplification factor. This segmentation allows high precision measurement across the full temperature range while organizing the circuit complexity into manageable, functionally distinct segments rather than a single complex amplifier.
Solution Approach 2:
Different amplification factors are applied to different temperature ranges based on local requirements. The first amplifier uses a first amplification factor optimized for the first temperature range, while the second amplifier uses a second amplification factor optimized for the second temperature range, allowing each part of the system to have the quality needed for its specific operating conditions.
3Adaptability or versatility
If the temperature detection range is expanded, then the adaptability is improved, but the measurement precision deteriorates due to quantization errors across the full range
Solution Approach 1:
The amplification factor dynamically adapts to the detected temperature range, allowing the system to maintain high measurement precision across an expanded temperature range. By switching between different amplification factors based on the current temperature range, the system achieves both wide adaptability and consistent precision that would be impossible with a single fixed amplification factor.
Solution Approach 2:
The amplification parameter is changed based on the detected temperature range, allowing the system to optimize measurement precision for different temperature conditions. The conversion circuit adjusts the amplification factor from a first value to a second value depending on which temperature range is detected, maintaining accuracy across the full expanded range.
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 enables precise temperature control of the heating member, ensuring accurate toner image fixation by minimizing the impact of quantization errors, particularly in the temperature range where image fixing occurs.
Implementation Method 1
a temperature sensor including a film configured to absorb infrared rays from the heating member
Implementation Method 2
a detection thermistor configured to output a first detection value corresponding to a temperature of the film, and a compensation thermistor configured to output a second detection value corresponding to a temperature of a holder holding the film
Data Source
AI summary
An image forming apparatus includes a heating member, a temperature sensor to output detection values for determining a temperature of the heating member, a first amplifier to amplify a difference value between the detection values with a first amplification factor, a second amplifier to amplify the difference value with a second amplification factor, a converter to generate first temperature information through analog-to-digital conversion of the difference value amplified by the first amplifier, generate second temperature information through analog-to-digital conversion of the difference value amplified by the second amplifier, and generate compensation temperature information, and a temperature determiner to determine the temperature of the heating member based on the second temperature information and the compensation temperature information, in a particular temperature range, and determine the temperature of the heating member based on the first temperature information and the compensation temperature information, outside the particular temperature range.