Capacitive Rotation Grating for Accurate Stage Lamp Angle Sensing
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Solution Overview
Problem
Existing stage lights face inaccuracies and complex structures in capacitive rotation angle detection, particularly for long-distance projection, due to limitations in photoelectric and magnetic encoders, and issues with transmission belts and gear deviations.
Innovation Solution
A stage light with capacitive rotation angle detection using a pivoting member and a supporting member, where a reflecting grating on the pivoting member and a signal grating on the supporting member are oppositely arranged, allowing direct capacitance measurement to improve accuracy and stability, with a simple structure design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If photoelectric encoder or magnetic encoder is used for rotation angle measurement, then measurement function is provided, but measurement precision and cost-effectiveness deteriorate due to limited accuracy and high price
Solution Approach 1:
The patent replaces the mechanical photoelectric encoder or magnetic encoder system with a capacitive detection system consisting of a signal grating and reflecting grating. This substitution eliminates complex mechanical components while achieving high-precision rotation angle measurement through capacitive coupling between the gratings, directly resolving the contradiction between measurement precision and device complexity.
Solution Approach 2:
The patent uses a reflecting grating that replicates the pattern of the signal grating to create capacitive coupling. The reflecting grating acts as a movable copy that, when rotated, changes the capacitive coupling with the stationary signal grating, enabling precise angle detection without complex encoding mechanisms.
2Ease of operation
If transmission belt and gear system is used for rotation transmission, then motion transmission is achieved, but measurement accuracy deteriorates due to elasticity and tooth skipping
Solution Approach 1:
The patent eliminates the transmission belt and gear system by directly coupling the capacitive detection system to the rotating shaft. The capacitive coupling between signal grating and reflecting grating provides direct rotational measurement without intermediate mechanical transmission components, thereby avoiding elasticity and tooth skipping issues.
3Measurement precision
If existing capacitive rotation angle detection is used, then capacitance measurement is provided, but measurement precision and manufacturing simplicity deteriorate due to inadequate accuracy and complex structure
Solution Approach 1:
The patent divides the capacitive detection system into two separate gratings: a stationary signal grating with capacitance emitting and receiving pieces, and a rotating reflecting grating with capacitance reflecting pieces. This segmentation allows each grating to have simpler individual structures while achieving high-precision measurement through their cooperative capacitive coupling.
Solution Approach 2:
The patent introduces a dielectric layer as an intermediary between the signal grating and reflecting grating. This dielectric layer facilitates controlled capacitive coupling while preventing direct contact between the gratings, enabling accurate angle measurement through capacitance changes without mechanical interference.
4Ease of operation
If conventional encoder system is used for long-distance projection positioning, then positioning function is provided, but positioning accuracy deteriorates due to deviation between measurement result and actual situation
Solution Approach 1:
The patent replaces conventional encoder systems with direct capacitive coupling detection that measures rotation angle without intermediate transmission components. This direct measurement approach eliminates the deviation between measured and actual positions, enabling accurate long-distance projection positioning.
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 provides more accurate and stable rotation angle measurement, preventing deviations in long-distance projection by utilizing capacitance change principles, while being resistant to oil pollution, dust, and humidity, and simplifying the design.
Implementation Method 1
the signal grating includes a plurality of capacitance emitting pieces, a capacitance receiving piece, and a shielding piece... the reflecting grating includes a plurality of capacitance reflecting pieces that reflect signals sent from the capacitance emitting pieces to the capacitance receiving piece
Data Source
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AI summary
The present invention discloses a capacitance type rotation angle detection stage light which comprises a pivoting member and a supporting member for supporting the pivoting member. A reflecting grating is attached on the pivoting member, and the reflecting grating rotates along with the pivoting member. A signal grating is attached on the supporting member. The signal grating and the reflecting grating are arranged oppositely. The signal grating comprises capacitance emitting pieces, a capacitance receiving piece and shielding pieces. The reflecting grating comprises capacitance reflecting pieces that reflect signals sent from the capacitance emitting pieces to the capacitance receiving piece. Periodic excitation signals applied to the capacitance emitting pieces finally form a composite signal on the capacitance receiving piece through coupling of two pairs of capacitors that the capacitance emitting pieces and the capacitance reflecting pieces, and the capacitance reflecting pieces and the capacitance receiving piece. Based on a principle of a capacitance change, with proper protection, there are advantages of oil pollution prevention, dust prevention, insensitivity to air humidity and temperature and the like. A rotation angle of the pivoting member is directly measured, a deviation in a transmission process thus will not affect measurement of an actual result.