Variable Slice Reference Level Generator for VBI Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional television systems face difficulties in accurately slicing vertical blanking interval (VBI) data due to noise, as fixed voltage reference levels are inadequate for varying noise magnitudes in closed-caption and teletext broadcasting services.
Innovation Solution
A device and method for generating variable slice reference levels using a high/low average value generator, reference value detector, and slice level generator, which set window intervals, detect average values, and produce high and low slice levels adjusted by a tuned factor to adapt to changing VBI data magnitudes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed voltage reference level is used for slicing VBI data, then the device complexity is reduced, but the measurement precision deteriorates due to varying noise magnitudes
Solution Approach 1:
The patent implements dynamic slice level adjustment by continuously monitoring the magnitude of VBI data and automatically modifying the reference level accordingly. The system transitions from a static fixed voltage reference to a dynamic reference that adapts to changing signal conditions, thereby maintaining slicing accuracy across varying noise environments without requiring complex manual calibration
Solution Approach 2:
The patent employs a feedback mechanism where the magnitude of incoming VBI data is continuously measured and fed back to the slice level generator. This feedback loop enables the system to detect noise levels and adjust the slice reference level in real-time, ensuring optimal slicing performance. The feedback-driven adaptation resolves the contradiction by automatically compensating for noise variations without adding significant device complexity
2Reliability
If additional reference signals are added to prevent slice errors, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The patent merges the reference signal generation function into the existing slice level generator, eliminating the need for separate additional reference signals. By combining multiple functions (magnitude detection, adaptive level generation, and slice level output) into a single integrated device, the system achieves improved reliability through adaptive behavior while avoiding the complexity increase that would result from adding separate reference signal generators
Solution Approach 2:
The slice level generator performs self-adjustment by automatically detecting the magnitude of VBI data and modifying its own reference level without requiring external control signals or additional reference generators. This self-service capability enhances reliability by enabling automatic compensation for noise and signal variations, while maintaining device simplicity through the elimination of external control mechanisms
3Ease of operation
If the slice level is fixed to an arbitrary voltage level, then the ease of operation is improved, but the manufacturing precision deteriorates for varying noise conditions
Solution Approach 1:
The system eliminates the need for manual slice level calibration by implementing self-adjusting behavior. The slice level generator automatically determines the appropriate reference level by monitoring VBI data magnitude, thereby maintaining ease of operation (no manual adjustment needed) while achieving high precision through adaptive calibration. This self-service approach resolves the contradiction by making the system both easy to operate and precise under varying conditions
Data Source
AI summary
A device and a method for generating a variable slice reference level. At least two variable slice reference levels used for slicing VBI data are generated. The device includes a high/low average value generator, a reference value detector, and a slice level generator. The high/low average value generator generates an average high value and an average low value of the VBI data using a plurality of window signals. The reference value detector generates an average reference value of the VBI data using the window signals. The slice level generator outputs a high slice level and a low slice level using the average high value, the average low value, the average reference value, and a tuned factor.