Derivative works — US Patent 8267537

Defensive Disclosure and Prior Art Derivations for U.S. Patent 8,267,537

Publication Date: May 13, 2026
Subject: Derivative designs and applications of a backlight unit fastening mechanism, as described in U.S. Patent 8,267,537, for the purpose of establishing prior art.

This document details novel variations, applications, and combinations of the core inventive concept of U.S. Patent 8,267,537 ("Backlight unit and display device having the same"). The patent describes a system comprising an LED module, a case with an integrated "bending part" to fix one end of the module, and a separate "fixing part" to secure another part of the module. The following disclosures expand upon this concept to render obvious future incremental improvements.

Derivations Based on Independent Claim 1: Backlight Unit

1. Material & Component Substitution

Derivative 1.1: Shape-Memory Alloy (SMA) Bending Part with Thermal Release

Enabling Description: The bending part (140) is fabricated from a shape-memory alloy, such as Nickel-Titanium (Nitinol). In its martensitic state at ambient temperature, the bending part is shaped to guide and securely clamp the end of the LED module (120). To release the module, a localized heating element (e.g., a resistive trace on the case or a focused infrared beam) heats the SMA bending part above its austenite transition temperature (e.g., 70°C). In its austenitic state, the SMA changes shape to a pre-programmed "open" position, releasing its clamping force on the LED module. The separate fixing part (130) is then removed, allowing for tool-less extraction of the module. This enables automated or remote servicing of backlight units.

Mermaid.js Diagram:

stateDiagram-v2
    [*] --> Unlocked
    Unlocked: Bending part is in "open" shape (Austenite)
    Unlocked --> Locked: Cools below transition temp.
    Locked: Bending part clamps LED module (Martensite)
    Locked --> Unlocked: Apply heat (>70°C)

Derivative 1.2: Magnetically Coupled Fixing Part and Conductive Case

Enabling Description: The fixing part (130) is replaced with a high-coercivity neodymium magnet assembly embedded within the LED module's housing. The case (110) is made from a ferromagnetic material (e.g., 400-series stainless steel). The LED module is inserted into the non-magnetic bending part (e.g., made of aluminum or a polymer) and then brought into proximity with the case, where the magnetic fixing part snaps it into place. The case and bending part also serve as electrical conductors (ground and V+), with contacts on the module completing the circuit upon installation, eliminating the need for separate wiring harnesses.

Mermaid.js Diagram:

flowchart TD
    A[Insert LED module into non-magnetic bending part] --> B{Bring module near ferromagnetic case};
    B --> C[Magnetic fixing part engages with case];
    C --> D[Electrical contacts on module mate with case/bending part];
    D --> E[LED module is secured and powered];

Derivative 1.3: Ceramic Case with Integrated Heat Pipe Bending Part

Enabling Description: The case (110) is molded from a thermally conductive ceramic, such as aluminum nitride (AlN) or beryllium oxide (BeO), providing superior thermal dissipation and electrical isolation. The bending part (140) is not merely a bent piece of the case material but is a hollow, micro-fabricated heat pipe integrated directly into the ceramic structure. One end of the heat pipe (the evaporator) makes direct thermal contact with the LED module's PCB. The other end (the condenser) is part of the larger case structure, dissipating heat to the ambient environment. This design combines the guiding/fixing function with active thermal management.

Mermaid.js Diagram:

classDiagram
    CeramicCase {
        +material: AlN
        +electricalIsolation: high
    }
    HeatPipeBendingPart {
        +isHollow: true
        +workingFluid: water/ammonia
        +evaporatorZone: contact with LED module
        +condenserZone: integrated with case
    }
    LEDModule {
        +pcb: MetalCorePCB
    }
    CeramicCase "1" -- "1..*" HeatPipeBendingPart : integrates
    HeatPipeBendingPart "1" -- "1" LEDModule : cools and fixes

2. Operational Parameter Expansion

Derivative 2.1: Cryogenic-Rated Backlight for Scientific Imaging

Enabling Description: A backlight unit designed for operation in cryogenic environments (e.g., liquid nitrogen at 77 K). The case (110) and bending part (140) are machined from an Invar alloy (FeNi36) to minimize thermal contraction and prevent stress on the LED module. The LED module (120) utilizes a ceramic substrate PCB to withstand thermal shock. The fixing part (130) is a spring-loaded latch made of beryllium copper, which retains its elasticity at cryogenic temperatures, ensuring a constant securing force on the module despite material contraction.

Mermaid.js Diagram:

graph TD
    subgraph Cryo Chamber (77K)
        A(Invar Case/Bending Part) -- fixes --> B(Ceramic Substrate LED Module);
        C(Beryllium Copper Latch) -- secures --> B;
    end
    D(External Controller) --> B;

Derivative 2.2: High-G & Vibration-Resistant Unit for Avionics

Enabling Description: For use in aerospace cockpit displays, the system is designed to withstand >20G acceleration and high-frequency vibrations. The bending part (140) is formed with a secondary locking tab that positively engages a slot in the LED module's PCB. The fixing part (130) is not a screw but a castellated nut with a cotter pin or a wired-in-place bolt, preventing any possibility of loosening due to vibration. The entire assembly is potted with a thermally conductive, vibration-damping silicone compound after the module is installed.

Mermaid.js Diagram:

sequenceDiagram
    participant User
    participant LEDModule
    participant BendingPart
    participant FixingPart
    User->>LEDModule: Slide into BendingPart
    BendingPart->>LEDModule: Primary guide engage
    User->>BendingPart: Engage secondary locking tab
    User->>FixingPart: Secure with castellated nut & cotter pin
    User->>User: Pot assembly with silicone

3. Cross-Domain Application

Derivative 3.1: Modular Grow Lighting for Vertical Farming (AgTech)

Enabling Description: The "case" is an extruded aluminum channel that doubles as a heat sink and structural support. The "bending part" is a clip at one end of the channel. The "LED modules" are 1-meter-long light bars with specific spectra (e.g., 450nm blue, 660nm red). A farmer can rapidly swap light bars by releasing a single quarter-turn fixing part at the other end and sliding the bar out of the bending part clip. This allows for changing the "light recipe" for different crops or stages of growth without tools.

Mermaid.js Diagram:

flowchart LR
    subgraph LightBar_Module
        A[PCB with Grow LEDs]
        B[Lens Array]
        C[Housing with contact pads]
    end
    subgraph Extruded_Channel_Case
        D[Bending Part Clip]
        E[Quarter-Turn Fastener]
    end
    LightBar_Module -- slides into --> D;
    LightBar_Module -- secured by --> E;

Derivative 3.2: Interchangeable Surgical Headlamp Modules (Medical)

Enabling Description: A surgeon's headlamp where the case is the main head-worn frame. The LED module is a sealed, sterilizable unit containing the LED and a specific collimating lens (e.g., for wide-field or narrow-spot illumination). A surgeon can switch between different light modules mid-procedure. The module slides into a bending part on the frame, and a single, gloved-hand-operable lever acts as the fixing part, locking the module in place and completing the electrical circuit. The materials are medical-grade PEEK polymer and 316L stainless steel.

Mermaid.js Diagram:

stateDiagram-v2
    state "No Module" as Off
    state "Spotlight Module" as Spot
    state "Floodlight Module" as Flood

    [*] --> Off
    Off --> Spot: Insert Spotlight module, engage lever
    Off --> Flood: Insert Floodlight module, engage lever
    Spot --> Off: Disengage lever, remove module
    Flood --> Off: Disengage lever, remove module

4. Integration with Emerging Tech

Derivative 4.1: IoT-Enabled Predictive Maintenance Backlight

Enabling Description: Each LED module (120) includes a microcontroller, a temperature sensor, and a photodiode to monitor its own health (lumen depreciation, CCT shift). The bending part (140) and fixing part (130) incorporate data and power contacts. When a module is installed, it automatically registers its unique ID and location on a cloud-based dashboard via a gateway. The system uses this real-time data to predict failures. A maintenance order is automatically generated, indicating the exact module to be replaced before catastrophic failure occurs.

Mermaid.js Diagram:

sequenceDiagram
    participant Technician
    participant LEDModule
    participant Case
    participant Gateway
    participant Cloud
    Technician->>LEDModule: Install into Case
    LEDModule->>Case: Power/Data connection established
    Case->>Gateway: Module ID [XYZ] connected at Loc [R2,C5]
    Gateway->>Cloud: Forward registration data
    loop Health Monitoring
        LEDModule->>Gateway: Send {Temp, Lumens, CCT}
        Gateway->>Cloud: Forward telemetry
    end
    Cloud->>Cloud: Analyze data, predict failure
    Cloud->>Technician: Generate work order for Module ID [XYZ]

Derivative 4.2: Blockchain-Verified Supply Chain for Replacement Modules

Enabling Description: At the point of manufacture, each LED module is assigned a unique, non-fungible token (NFT) on a supply chain blockchain. This token records its manufacturing date, test results, and provenance. The case is equipped with a small reader. When a new module is installed, the reader verifies the module's NFT on the blockchain to ensure it is an authentic, certified part and not a counterfeit. The act of installation is recorded as a transaction on the blockchain, creating an immutable service log for the display device.

Mermaid.js Diagram:

flowchart TD
    A[OEM: Mint NFT for new LED Module] --> B(Module shipped to Service Center);
    B --> C{Technician installs Module into Display};
    C --> D[Display's internal reader scans Module's unique ID];
    D --> E{Reader queries Blockchain for NFT validity};
    E -- Valid --> F[Display accepts Module, records installation transaction];
    E -- Invalid --> G[Display rejects Module, alerts Technician];

5. The "Inverse" or Failure Mode

Derivative 5.1: Bimetallic Strip for Passive Thermal Cut-off

Enabling Description: The bending part (140) is constructed from a bimetallic strip. Under normal operating temperatures, its shape provides the necessary clamping force. If the LED module overheats (e.g., due to LED failure or poor thermal contact), the differential expansion of the metals causes the strip to bend away from the module. This action physically breaks the power connection at that end of the module, de-energizing it and preventing a fire hazard. The module remains held in place by the fixing part (130) but is visibly and electrically disconnected.

Mermaid.js Diagram:

graph TD
    subgraph Normal_Operation
        A(Bimetallic Bending Part) -- clamps & powers --> B(LED Module);
    end
    subgraph Overheat_Condition
        C(Bimetallic Bending Part) -- deforms --> D(Breaks power connection);
        B -- heats --> C;
    end
    Normal_Operation --> Overheat_Condition;

Combination Prior Art Scenarios

Combination with VESA and Open-Source Controller: A large-format display case is designed with standard VESA mounting holes on its exterior. Internally, it uses the bending part/fixing part mechanism to hold a grid of LED backlight modules. Each module communicates its status using the open I2C protocol via contacts in the bending part. An internal controller, based on an open-source Raspberry Pi Compute Module, polls each module via I2C and can report the status of any failed module to a central management system, enabling field-swappable repairs of VESA-mounted digital signage.
Combination with Open-Source Hardware (OSHWA) Chassis: The mechanical design for the case (110) and its integrated bending parts (140), including all CAD files and dimensional tolerances, is published under the CERN Open Hardware License (CERN-OHL-S). This allows third-party manufacturers to build compatible chassis and LED modules, fostering an ecosystem of interchangeable parts for modular video walls, while the core mechanism of retention remains as described.
Combination with USB-C Power Delivery Standard: The connection between the LED module and the case uses a ruggedized connector compliant with the USB Type-C standard. The bending part guides the module into the connector. The fixing part (e.g., a thumbscrew) secures the module, preventing disconnection. This allows the module to be powered and controlled using the USB Power Delivery (USB-PD) protocol, enabling standardized power rails and intelligent power negotiation within the display, reducing the need for proprietary power supplies.