HDMI Port Detection Circuit Using Duty Cycle Analysis

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Solution Overview

Problem

Existing systems require multiple microprocessor ports to identify and communicate with multiple HDMI ports, leading to inefficient utilization and increased port requirements, especially as the number of HDMI ports increases.

Innovation Solution

A circuit using a 555D integrated timer circuit and field-effect transistors generates a duty cycle alteration signal, allowing a single microprocessor port to detect which HDMI ports are occupied by external devices through changes in impedance, enabling efficient identification and communication with multiple ports.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If each HDMI port is connected to a separate microprocessor port, then each HDMI port can be independently detected and communicated with, but the number of microprocessor ports increases linearly with the number of HDMI ports, leading to inefficient utilization

Engineering Contradiction:
ImproveHDMI port detection accuracyVSAvoidnumber of microprocessor ports
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Multiple HDMI port detection functions are merged into a single microprocessor port. The patent connects multiple HDMI ports to one microprocessor port through a shared circuit that uses duty cycle analysis to distinguish between different ports, thereby reducing the number of microprocessor ports required while maintaining detection accuracy

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

An intermediary circuit is introduced between the HDMI ports and the microprocessor port. This circuit includes components that generate duty cycle signals specific to each HDMI port, acting as a mediator that enables the microprocessor to identify occupied ports through duty cycle analysis rather than requiring direct separate connections

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If multiple microprocessor ports are used for HDMI port detection, then each port can be independently identified, but the system efficiency decreases due to increased port requirements and resource consumption

Engineering Contradiction:
ImproveHDMI port identification reliabilityVSAvoidsystem efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent combines multiple HDMI port monitoring functions into a single microprocessor port by implementing a shared circuit architecture. This merging reduces resource consumption and improves system efficiency while maintaining reliable port identification through duty cycle-based detection

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the detection parameter from direct port connection status to duty cycle characteristics. By analyzing the duty cycle of signals received on the single microprocessor port, the system can reliably identify which HDMI ports are occupied without requiring multiple dedicated ports, thereby improving efficiency

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2028854B1Efficient method and circuit for using HDMI ports
Publication Date: 2011.07.27 VESTEL ELEKTRONIK SANAYI & TICARET ANONIM SIRKETI
  • EP2028854B1 patent drawingFigure 1~2
  • EP2028854B1 patent drawingFigure 3
  • EP2028854B1 patent drawingFigure 4

AI summary

More than one HDMI port is currently used on televisions and on other video systems for enhancing the user's benefit from the device. A microprocessor provided in a system equipped with more than one HDMI port must identify as to which external device is connected to which HDMI port and must communicate with that port during operation. Thanks to the present invention, the presence of connection of external devices to HDMI ports is identified by making use of a single one port of the microprocessor of the system, regardless the number of HDMI ports.