DDC Communication Module Using Repeater to Extend EDID Signal Distance

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Solution Overview

Problem

Conventional DDC communication modules experience noise and signal attenuation in long-range communication.

Innovation Solution

A DDC communication module comprising a serial EEPROM, a comparator, and a controller that reads and stores EDID from a display device and provides it to a host device, using a modified access address based on the comparator's logical output to differentiate between connections to display and host devices, thereby overcoming noise and signal attenuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If conventional DDC communication modules are used for long-range communication, then communication distance can be extended, but noise and signal attenuation occur

Engineering Contradiction:
Improvecommunication distanceVSAvoidsignal quality
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The patent introduces a repeater as an intermediary device between the host device and display device. The repeater receives EDID data from the display device and retransmits it to the host device, acting as a signal mediator that regenerates and strengthens the signal along the communication path, thereby enabling long-range communication without noise and signal attenuation

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The repeater creates a copy of the EDID data transmitted from the display device and retransmits this copied data to the host device. This copying process allows the signal to be regenerated and refreshed at intermediate points, maintaining signal quality over extended communication distances

Inventive Principle:
Principle #26Copying

2Length of stationary object

If a DDC communication cable is used for long-range communication, then communication distance can be extended, but noise and signal attenuation occur

Engineering Contradiction:
Improvecommunication distanceVSAvoidnoise and signal attenuation
Core Design Contradiction:
Length of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The repeater serves as an intermediary that receives, processes, and retransmits signals, eliminating the need for extended cable lengths. By placing repeaters at strategic intervals, the system achieves long-range communication while keeping individual cable segments short, thereby avoiding noise and signal attenuation associated with long cables

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The communication path is segmented into multiple shorter segments separated by repeaters. Instead of using one long cable, the system divides the communication channel into multiple short links, each immune to noise and attenuation, with repeaters bridging the segments

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2055081B1DDC communication module
Publication Date: 2018.09.26 OPTICIS CO LTD
  • EP2055081B1 patent drawingFigure 1
  • EP2055081B1 patent drawingFigure 2
  • EP2055081B1 patent drawingFigure 3

AI summary

Provided is a display data channel (DDC) communication module reading and storing extended display identification data (EDID) of a display device and providing the stored EDID to a host device. The DDC communication module includes: a serial electrically erasable and programmable read only memory (EEPFROM) in which the EDID is stored; a comparator outputting logic data indicating that the comparator is connected to the display device or the host device; and a controller reading and storing EDID, or providing EDID stored in the serial EEPROM to the host device, according to the logic data output from the comparator.