Clock Synchronization via SPDIF for Content Data Transmission
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Solution Overview
Problem
Existing content data transmission systems between content reproduction and output apparatuses face issues with jitter and degradation in audio and video quality due to unsynchronized master clocks, requiring complex signal processing and additional circuits, and user settings can be cumbersome and error-prone.
Innovation Solution
The system employs an operation clock transmission using an SPDIF cable to synchronize the content reproduction apparatus with the content output apparatus, eliminating the need for complex signal processing and additional circuits, and automatically checks compatibility to ensure seamless data transmission without degrading sound or image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If master clocks of content reproduction apparatus and content output apparatus are not synchronized, then the system can operate independently without complex synchronization mechanisms, but jitter is generated in transmitted content data causing noise, audio interruption, or video quality degradation
Solution Approach 1:
The patent introduces an operation clock signal as an intermediary that is transmitted from the content output apparatus to the content reproduction apparatus. This operation clock serves as a mediator to synchronize the clocks of both apparatuses, eliminating jitter in the content data transmission without requiring complex bidirectional synchronization protocols. The operation clock is extracted from the content data transmission path and used to control the reproduction apparatus timing.
Solution Approach 2:
Instead of having the content reproduction apparatus generate its own master clock independently (traditional approach), the patent inverts the approach by having the content output apparatus generate the operation clock and transmit it to the reproduction apparatus. This inversion centralizes clock control at the output apparatus, simplifying the synchronization mechanism while ensuring reliable content data transmission.
2Reliability
If complex signal processing and additional circuits are added to synchronize clocks, then clock synchronization reliability improves, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent makes the operation clock signal serve multiple functions: it is used both for synchronizing the content reproduction apparatus and for controlling the timing of content data transmission. By extracting the operation clock from the existing content data transmission path (SPDIF interface) and reusing it for synchronization purposes, the patent avoids adding dedicated synchronization circuits while maintaining reliable clock synchronization.
Solution Approach 2:
The content output apparatus generates the operation clock from its own internal timing resources and transmits it to the content reproduction apparatus. This self-service approach allows the output apparatus to control the synchronization without requiring external synchronization equipment or complex bidirectional negotiation protocols, simplifying the overall system architecture.
3Measurement precision
If manual clock synchronization settings are required, then precise clock control can be achieved, but ease of operation decreases and user errors increase
Solution Approach 1:
The patent implements automatic clock synchronization where the content reproduction apparatus receives the operation clock signal and automatically adjusts its internal timing based on this feedback signal. The system continuously monitors the operation clock and dynamically synchronizes its operations, eliminating the need for manual setup while maintaining precise synchronization. This closed-loop approach ensures accurate timing without user intervention.
Data Source
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AI summary
[Problem] In a system that transmits content data from a content replay device to a content output device, to prevent a deterioration in audio quality or video data picture quality while being able to increase the simplicity of a setting-altering operation without requiring complicated signal processing. [Solution] The present invention is provided with: the content replay device, which receives an operation clock signal transmitted from the content output device via an operation clock transmission cable, operates on the basis of the operation clock signal, and transmits content data replayed by a replay unit to the content output device via a multimedia transmission cable; and the content output device, which generates the operation clock signal transmitted to the content replay device on the basis of an output device operation clock signal, transmits the operation clock signal to the content replay device via the operation clock transmission cable, and receives, performs signal processing on, and outputs to an external device the content data transmitted from the content replay device via the multimedia transmission cable.