Backlight Detection Circuit for LED Shutdown
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Solution Overview
Problem
Conventional LCD devices experience abnormal color display and reduced quality due to uncontrolled power release from capacitors and windings when AC power is cut off, leading to noise colors like red and blue noise.
Innovation Solution
A backlight system with a detection circuit that monitors the power input circuit's connection state and sends signals to a control circuit to control the light emitting diode driving circuit, ensuring immediate shutdown of the LED array when disconnected from the external power source, preventing uncontrolled power release and noise colors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If capacitors and windings are used to filter surge voltages and store electrical power, then power stability is improved, but abnormal color display occurs when AC power is cut off due to uncontrolled power release
Solution Approach 1:
The detection circuit continuously monitors the AC power input state and provides feedback to the control circuit. When AC power disconnection is detected, the control circuit immediately responds by shutting down the LED array through the LED driving circuit, preventing the harmful effect of uncontrolled power release from capacitors and windings.
Solution Approach 2:
The detection circuit is configured to detect AC power disconnection in advance before the stored electrical power in capacitors and windings can cause abnormal color display. By detecting the power state change preliminarily, the system can take preventive action to shut down the LED array before the harmful effect occurs.
2Manufacturing precision
If a detection circuit and control circuit are added to detect power connection state and control LED shutdown, then display quality is improved, but device complexity increases
Solution Approach 1:
The detection circuit serves multiple functions: it detects AC power connection state, generates control signals for the LED array shutdown, and prevents abnormal color display. By making the detection circuit multi-functional, the patent reduces the need for separate dedicated circuits for each function, thereby minimizing the increase in device complexity while achieving the goal of improving display quality.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively eliminates color noise and improves display quality by ensuring immediate shutdown of the LED array when AC power is cut off, maintaining aesthetic appeal and display integrity.
Implementation Method 1
a light emitting diode array 26. The backlight system is coupled to the power input circuit and is configured to detect a connection state of the power input circuit with respect to an external power source, and is further configured to provide or stop providing light beams to illuminate the liquid crystal display panel
Data Source
AI summary
An exemplary backlight system includes a power input circuit (21), a detection circuit (27), a control circuit (28), a light emitting diode driving circuit (25), and a light emitting diode array (26). The detection circuit is configured to detect a connection state of the power input circuit with respect to an external power source, and send a corresponding connection states signal to the control circuit. The control circuit is configured to output a control signal to the light emitting diode driving circuit according to the connection state signal. The light emitting diode driving circuit is configured to drive or shut down the light emitting diode array according to the control signal.