Display Panel Driver PLL Training for Stability

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Solution Overview

Problem

Display devices face challenges in maintaining stable operation, particularly when operating at variable frequency modes, where abnormal operations such as malfunctions due to static electricity can occur, and existing technologies lack effective recovery mechanisms.

Innovation Solution

A display device with a panel driver that includes a data driver and a driving controller, which applies a training synchronizing signal during variable blank periods or holding periods to periodically perform a training operation on the phase locked loop, allowing for recovery from abnormal operations like malfunctions or static electricity issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the data driver operates in variable frequency mode without blank periods, then productivity is improved, but reliability deteriorates due to inability to recover from abnormal operations

Engineering Contradiction:
Improvedisplay refresh rateVSAvoidoperation stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by performing PLL training during holding periods before normal operation. The training synchronizing signal is applied in advance during holding periods to train the PLL, so that when abnormal operations occur, the PLL is already prepared and can recover more effectively. This proactive training during idle holding periods resolves the contradiction by maintaining productivity while preemptively ensuring reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements periodic action by applying the training synchronizing signal at regular intervals during holding periods. The PLL training is performed periodically rather than continuously, allowing the display to maintain high refresh rates while intermittently training the PLL to ensure stability. This periodic training during holding periods resolves the contradiction between productivity and reliability.

Inventive Principle:
Principle #19Periodic action

2Productivity

If blank periods are removed from driving frames, then productivity is improved, but ease of repair deteriorates due to lack of recovery mechanism

Engineering Contradiction:
Improvedisplay refresh rateVSAvoidrecovery from malfunction
Core Design Contradiction:
ProductivityVSEase of repair

Solution Approach 1:

The patent uses preliminary action by preparing the PLL through training during holding periods before potential malfunctions occur. The training synchronizing signal is applied in advance during these periods, so when abnormalities occur, the system is already primed for recovery. This resolves the contradiction by maintaining continuous operation while preemptively enabling repair capabilities.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces the training synchronizing signal as an intermediary element that facilitates PLL recovery. This special signal acts as a mediator between the driving controller and the data driver, enabling recovery from malfunctions without requiring traditional blank periods. The intermediary training signal resolves the contradiction by providing repair capability through a different mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the phase locked loop is trained continuously, then reliability is improved, but use of energy increases

Engineering Contradiction:
ImprovePLL stabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by training the PLL only during holding periods at regular intervals, rather than continuously. The training synchronizing signal is applied periodically during these idle periods, maintaining PLL stability while avoiding continuous energy consumption. This resolves the contradiction between reliability and energy usage by making the training process intermittent rather than continuous.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent maintains continuity of useful action by utilizing holding periods that would otherwise be idle for PLL training. Instead of wasting these periods, the system performs beneficial PLL training, ensuring both reliability and energy efficiency. This resolves the contradiction by making productive use of existing idle time rather than adding continuous training operations.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentUS11972730B2Display device
Publication Date: 2024.04.30 SAMSUNG DISPLAY CO LTD
  • US11972730B2 patent drawing
  • US11972730B2 patent drawing
  • US11972730B2 patent drawing

AI summary

A display device includes: a display panel and a panel driver for driving the display panel during a plurality of driving frames whose frequencies are varied. Among the driving frames, a first driving frame having a first frequency includes a first write period, and a second driving frame having a second frequency lower than the first frequency includes a second write period and a variable blank period. The panel driver includes a data driver and a driving controller. Each of the first and second write periods includes N horizontal periods (N is an integer number equal to or greater than 1), each of the N horizontal periods has a first duration, and each of the first and second write periods has a second duration corresponding to N times of the first duration. The driving controller applies a training synchronizing signal to the data driver during the variable blank period.