Projection Display Diaphragm Control for Noise Reduction
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Solution Overview
Problem
Existing projection display apparatuses face issues with driving sound and motor deterioration due to continuous operation of the diaphragm, particularly when frequent dimming is necessary, as they rely heavily on motor-driven diaphragms which can cause noise and wear.
Innovation Solution
A control apparatus that calculates a target dimming rate based on image data features, controls the diaphragm position, and adjusts the light source quantity to minimize diaphragm operation frequency, using threshold settings and hysteresis characteristics to reduce motor driving noise and deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the diaphragm is used for frequent dimming control, then the light quantity can be adjusted to improve image contrast, but the motor driving the diaphragm experiences continuous operation causing driving sound noise and motor deterioration
Solution Approach 1:
The patent applies periodic action by controlling the light source to operate intermittently rather than continuously. The control apparatus calculates a target dimming rate based on image data features, and the light source controller adjusts the light source output in periodic cycles to achieve the desired dimming effect without requiring continuous diaphragm adjustment. This reduces the operational frequency of the diaphragm motor, thereby suppressing driving sound and motor deterioration while maintaining the ability to adjust light quantity for image contrast improvement.
2Illumination intensity
If the diaphragm is used for frequent dimming control, then the light quantity can be adjusted to improve image contrast, but driving sound of the motor is heard as noise
Solution Approach 1:
The patent applies periodic action by controlling the light source to operate intermittently rather than continuously. The control apparatus calculates a target dimming rate based on image data features, and the light source controller adjusts the light source output in periodic cycles to achieve the desired dimming effect without requiring continuous diaphragm adjustment. This reduces the operational frequency of the diaphragm motor, thereby suppressing driving sound and motor deterioration while maintaining the ability to adjust light quantity for image contrast improvement.
3Reliability
If the light source emission quantity is controlled to adjust light quantity, then the diaphragm operation frequency can be reduced, but the precision of light quantity control may be insufficient
Solution Approach 1:
The patent merges two control mechanisms: diaphragm position control and light source emission quantity control. The control apparatus calculates a target dimming rate based on image data features, then determines both the optimal diaphragm position and light source output level. By combining these two control methods, the system achieves precise light quantity adjustment through light source control while using diaphragm adjustment only when necessary, thereby maintaining control precision while reducing motor operation frequency and extending motor durability.
Data Source
AI summary
A control apparatus includes a calculator that calculates a target dimming rate of a projection display apparatus based on a feature quantity of image data, a diaphragm controller that controls a diaphragm position of a diaphragm based on a target diaphragm position set for each range to which the target dimming rate belongs, and a light source controller that controls a light quantity of a light source on the basis of the target dimming rate and the diaphragm position.