Velocity Detecting Apparatus Stain Correction
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Solution Overview
Problem
The existing velocity detecting apparatuses in multifunction peripherals, such as printers, face inaccuracies in detecting carriage velocity due to stains on the encoder strips, which alter the light reception and lead to erroneous velocity detection.
Innovation Solution
A velocity detecting apparatus comprising a region formation member with alternating optically transmissive and non-transmissive regions, an optical sensor to emit light and output pre-correction pulse signals, and a controller to correct these signals by switching between different levels based on specific conditions, ensuring accurate detection of carriage velocity despite stains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an optical sensor and encoder strip are used to detect carriage velocity, then velocity detection is enabled, but stains on the encoder strip cause light reception errors and reduce measurement precision
Solution Approach 1:
The system dynamically adjusts the pulse signal levels based on detected stains. When a stain is detected in a first region, the system switches the pulse signal from a first level to a second level. When the stain moves to a second region, it switches back. This dynamic adaptation compensates for the harmful effect of stains and maintains measurement precision.
Solution Approach 2:
The invention changes the parameter of pulse signal level in response to stain detection. By switching between first and second levels based on the position of stains relative to the optical sensor, the system compensates for light reception errors caused by stains, thereby maintaining velocity detection precision.
2Reliability
If the optical sensor receives larger light from the second region than the first region, then signal differentiation is enhanced, but stains alter light reception and cause detection errors
Solution Approach 1:
The system uses feedback from the optical sensor to detect stains and adjusts the pulse signal levels accordingly. When the sensor detects altered light reception patterns indicating a stain's presence, the controller switches signal levels to compensate, maintaining both reliability and precision.
Solution Approach 2:
The pulse signal levels are dynamically switched based on real-time detection of stain positions. The system transitions from static signal levels to dynamic adjustment, switching between first and second levels as stains move across different regions, thereby maintaining measurement accuracy despite varying light reception conditions.
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 accurately calculates the moving velocity of the carriage by correcting pulse signals, thereby improving the precision of velocity detection and reducing errors caused by stains on the encoder strips.
Implementation Method 1
The region formation member has a first region and a second region that are arranged cyclically in the scanning direction. The first region and the second region have different optical characteristics from each other. The optical sensor is configured to emit light to the region formation member and to output a pre-correction pulse signal that is on a first level when facing the first region and that is on a second level when facing the second region.
Data Source
AI summary
A controller performs: correcting a pre-correction pulse signal and outputting the corrected pre-correction pulse signal as a post-correction pulse signal that switches between third and fourth levels, the correcting including: switching the post-correction pulse signal from the third to fourth level when first or second condition is satisfied, the first condition being that the pre-correction pulse signal switches from the first to second level, the second condition being that duration of the third level exceeds a first reference period; and switching the post-correction pulse signal from the fourth to third level when both of third and fourth conditions are satisfied, the third condition being that duration of the fourth level exceeds a second reference period, the fourth condition being that the pre-correction pulse signal is on the first level; and calculating a relative moving velocity of the moving device based on temporal changes between the third and fourth levels.