Reflective Optical Sensor Calibration for Sheet Detection Accuracy
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Solution Overview
Problem
Reflective optical sensors in image processing apparatuses face challenges in accurately detecting sheet presence and position due to variations in image density and distance, leading to erroneous detection results.
Innovation Solution
An inspection apparatus with a movable reflective optical sensor and adjustable light emission, using reference sheets of different image densities to calibrate and correct the detection distance and light emission, ensuring accurate sheet detection by comparing output signals to predetermined threshold values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a reflective optical sensor is used to detect sheet presence and position, then the detection function is provided, but detection accuracy deteriorates due to variations in image density and distance
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the light emission intensity of the light emitter based on the detected image density of the sheet. The control unit modifies the light emission parameters to compensate for variations in sheet reflectivity, ensuring consistent detection accuracy across different image densities and distances.
2Measurement precision
If the light emission intensity is increased to improve detection of dark images, then detection capability for dark images is improved, but energy consumption increases
Solution Approach 1:
The patent implements dynamics by making the light emission intensity adjustable and adaptive rather than fixed. The control unit dynamically changes the light emission intensity based on real-time detection of sheet image density, using higher intensity for dark images and lower intensity for light images, thereby optimizing both detection accuracy and energy consumption.
Solution Approach 2:
The system changes the light emission parameter (intensity) based on the detected sheet characteristics. By adjusting this parameter dynamically, the system achieves efficient energy utilization while maintaining detection accuracy across varying image densities.
3Device complexity
If the sensor position is fixed, then device structure is simplified, but detection accuracy deteriorates due to distance variations
Solution Approach 1:
The patent compensates for fixed sensor position limitations by changing the light emission intensity parameter. The control unit adjusts the light intensity to account for distance variations between the sensor and sheet, maintaining detection accuracy without requiring mechanical sensor position adjustment.
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 ensures accurate detection of sheets with varying image densities and distances, reducing errors and ensuring reliable operation of image processing apparatuses by adjusting light emission and sensor position dynamically.
Implementation Method 1
The reflective optical sensor applies light to a document to be detected, and receives light reflected by the document
Implementation Method 2
a photodetector that receives the light and outputs a received-light signal as an output signal
Data Source
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AI summary
A control portion of a sheet detection device causes a light emitter to emit light with a predetermined amount of light emission, to determine whether or not a first reference sheet is in a detection area. When the first reference sheet is not in the area, a sheet detection sensor is moved upward by a predetermined movement pitch. When the first reference sheet is in the area, the present detection distance between the sheet detection sensor and the first reference sheet is stored. The control portion performs the same process for the second reference sheet. When both of the detection distances are correct, the control portion determines that an output from the sheet detection sensor is correct, and sets the present amount of light emission as an amount of light emission for a document detection process. When both of the detection distances are not correct, the output is determined as being incorrect, and an amount of light emission from the light emitter is increased by one step.