Endoscope Light Control Using Dynamic Threshold Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Endoscope apparatuses employing semiconductor light-emitting elements face challenges in maintaining optimal color balance and light intensity control, particularly when using multiplexed light from multiple LEDs, which can lead to suboptimal image quality due to variations in light detection and feedback control.
Innovation Solution
An endoscope apparatus with a control system that adjusts the drive signal for semiconductor light-emitting elements based on intensity detection, using optical sensors to maintain a predetermined color balance by controlling current values and duty cycles of PWM pulses, ensuring optimal light adjustment and color balance across different observation modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If feedback control is performed using optical sensors to maintain color balance, then color balance accuracy is improved, but measurement precision deteriorates when light intensity exceeds sensor threshold
Solution Approach 1:
The control method dynamically switches between two control strategies: when detected light intensity is below the threshold, feedback control using optical sensors is applied to maintain color balance accuracy; when intensity exceeds the threshold, the system transitions to open-loop control with predetermined drive signals to ensure reliable operation. This dynamic adaptation resolves the contradiction by selecting the appropriate control mode based on real-time light intensity conditions.
Solution Approach 2:
The invention changes the control parameter from continuous feedback control to pulsed light emission with adjusted duty cycles when light intensity exceeds sensor thresholds. By modifying the duty cycle of pulsed emissions rather than relying on feedback from overloaded sensors, the system maintains both color balance accuracy and detection reliability across different light intensity conditions.
2Illumination intensity
If continuous light emission is used to ensure sufficient illumination, then brightness is improved, but energy consumption increases
Solution Approach 1:
The invention employs periodic pulsed light emission instead of continuous illumination. By emitting light in pulses with controlled duty cycles, the system achieves sufficient average brightness for endoscopic observation while significantly reducing energy consumption compared to continuous operation. The pulsed mode allows the illumination to meet observational requirements without sustained high power draw.
3Use of energy by moving object
If pulsed light emission with adjusted duty cycle is used to reduce energy consumption, then energy efficiency is improved, but light intensity control precision deteriorates
Solution Approach 1:
The system incorporates feedback control using optical sensors to detect actual light intensity and adjust drive signals accordingly. When operating in pulsed mode for energy efficiency, the feedback mechanism monitors the resulting light output and modifies duty cycles or pulse widths to maintain precise light intensity control. This feedback loop ensures that energy-efficient pulsed operation does not sacrifice control precision.
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 system effectively maintains a predetermined color balance and light intensity, enhancing image quality by dynamically adjusting the light output from multiple LEDs, even when sensor values are below threshold, thereby improving the overall performance of the endoscope apparatus.
Implementation Method 1
a first semiconductor light-emitting element configured to generate light having an intensity according to a current value of an inputted drive signal
Implementation Method 2
a first detection section configured to receive a part of the light generated from the first semiconductor light-emitting element and detects the intensity
Data Source
AI summary
An endoscope apparatus includes: a first semiconductor light-emitting element; a light source drive section; a first detection section; a storage section configured to store a threshold value indicating whether or not the first detection section can correctly detect an intensity; and a control section configured to, if the intensity detected by the first detection section exceeds the threshold value stored in the storage section, control the current value of the drive signal based on the intensity detected by the first detection section, for the light source drive section, and if the intensity detected by the first detection section does not exceed the threshold value, perform control so as to make the current value of the drive signal constant to provide pulsed light emission and change a duty cycle or a number of pulses to perform light adjustment, for the light source drive section.