Backlight Unit Enable Signal Circuit for Unconnected Module Protection
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Solution Overview
Problem
Existing backlight units for liquid crystal displays (LCDs) face reliability issues due to potential damage from unconnected light source modules, leading to malfunction and reduced reliability.
Innovation Solution
The proposed solution involves a backlight unit design that stops generating driving voltage when the light source module is not connected to the connector, preventing damage and ensuring the unit remains operational and reliable by using enable signals to control the power converter and driving circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the power converter continuously generates driving voltage, then the backlight unit can operate without interruption, but the backlight unit may be damaged or malfunction when the light source module is not connected
Solution Approach 1:
The patent applies preliminary action by detecting whether the light source module is connected to the connector before the power converter generates driving voltage. The connector detection circuit checks the connection status in advance, and only when connection is confirmed does the enable signal allow voltage generation. This prevents damage from unconnected modules while ensuring continuous operation when properly connected.
2Duration of action of stationary object
If the enable signal is always active, then the driving circuit operates continuously ensuring no interruption, but the driving circuit may cause malfunction when light source module is unconnected
Solution Approach 1:
The patent implements feedback by using the connector detection circuit to monitor the connection status of the light source module and providing this information back to the control circuit. The control circuit adjusts the enable signal based on this feedback - activating it when connected and deactivating it when unconnected, thus ensuring continuous operation only under safe conditions.
3Device complexity
If no connection detection is implemented, then the device structure remains simple, but the backlight unit cannot prevent damage from unconnected light source modules
Solution Approach 1:
The patent introduces an intermediary element - the connector detection circuit - that mediates between the power converter and the light source module connection status. This detection circuit acts as a intermediary that checks connection status and controls the enable signal accordingly, preventing damage without requiring major structural changes to the overall system.
Data Source
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AI summary
A backlight unit (10) includes a light source module (150) including a first connection pin (P1) and a second connection pin (P2) electrically connected to the first connection pin via a signal line (L1). Also provided is a light source driving circuit board (100) including a power converter (120) which provides a driving voltage (VLED) to the light source module, a connector (140) which receives a first enable signal (EN1) via a first enable signal line (SL1) and which provides a second enable signal (EN2) via a second enable signal line (SL2), and a driving circuit (130) which controls (CTRLV) a generation of the driving voltage from the power converter in response to the second enable signal. When the connector is electrically connected to the first and second connection pins, the first enable signal (EN1) is transmitted to the first connection pin (P1) whereby, via the signal line (L1), the second enable signal (EN2) emerges from the second connection pin (P2) and is provided to the driving circuit (130) via the connector and the second enable signal line (SL2).