Derivative works — US Patent 7936415

Defensive Disclosure and Prior Art Generation for Modular Lighting Systems

Publication Date: April 26, 2026
Reference Patent: US 7,936,415 B2 ("the '415 patent")
Purpose: This document discloses a series of derivative inventions, enhancements, and alternative embodiments related to the modular light source apparatus described in the '415 patent. The intent is to place these concepts into the public domain to serve as prior art for future patent applications in this field. The disclosures herein are described in sufficient detail to enable a Person Having Ordinary Skill in the Art (PHOSITA) to practice the inventions without undue experimentation.

Axis 1: Material & Component Substitution

1.1. Flexible Graphene-on-Polyimide Substrate for Conformal Lighting

Enabling Description: The module substrate (analogous to 121 in the '415 patent) is fabricated from a flexible polyimide film. The conductive circuit patterns (135) and LED lead electrodes (131) are formed using transparent, flexible graphene traces deposited via chemical vapor deposition (CVD). The connecting substrates (140) are similarly constructed. Micro-LEDs (< 100µm) are mounted using a flip-chip thermocompression bonding process. The termination substrate (145) is also flexible and includes a printed resistor to form the closed-loop circuit termination. This assembly allows the entire LED light bar to conform to curved surfaces, such as the inside of a vehicle's A-pillar or a cylindrical display, while maintaining electrical integrity. The use of transparent graphene conductors minimizes light obstruction and improves overall optical efficiency.

Mermaid Diagram:

graph TD
    subgraph Flexible LED Bar
        A[Module 1: Graphene on Polyimide] -- Connector --> B[Module 2: Graphene on Polyimide];
        B -- Connector --> C[Module N: Graphene on Polyimide];
        C -- Terminator --> D{Termination Circuit};
    end
    A -- contains --> A_LEDs[Micro-LEDs];
    B -- contains --> B_LEDs[Micro-LEDs];
    C -- contains --> C_LEDs[Micro-LEDs];
    E[Curved Surface] --> A;
    E --> B;
    E --> C;

1.2. High-Thermal-Conductivity Ceramic Modules with Liquid Metal Interconnects

Enabling Description: For high-power applications (e.g., stadium lighting, industrial UV curing), the module substrate is fabricated from Aluminum Nitride (AlN) or Beryllium Oxide (BeO), offering thermal conductivity >150 W/mK. High-power Chip-on-Board (COB) LEDs are directly bonded to the ceramic substrate. Instead of solder-based connections, the connecting terminals at the ends of each module are recessed wells. The connecting substrates feature corresponding protrusions. The electrical connection is made by injecting a Gallium-Indium-Tin eutectic alloy (Galinstan) into the wells after mating the modules. The termination substrate contains a closed-loop pattern formed by a thick-film resistor printed and fired directly onto the ceramic. This design provides superior thermal management and a robust, vibration-resistant electrical connection.

Mermaid Diagram:

sequenceDiagram
    participant Mod1 as AlN Module 1
    participant Conn as Connecting Substrate
    participant Mod2 as AlN Module 2
    Mod1->>Conn: Mechanical Mating (Protrusion in Well)
    activate Conn
    participant Injector
    Injector->>Conn: Inject Galinstan
    Conn->>Mod1: Liquid Metal fills Terminal 1 Well
    Conn->>Mod2: Liquid Metal fills Terminal 2 Well
    deactivate Conn
    Note right of Mod2: Electrical & Thermal Path Established

Axis 2: Operational Parameter Expansion

2.1. Micro-Scale Modular Light Engine for Waveguides

Enabling Description: The invention is scaled down for use in near-eye displays, such as augmented reality glasses. The "module substrates" are silicon interposers less than 1mm wide, each carrying a linear array of three Gallium Nitride (GaN) micro-LEDs (Red, Green, Blue). The connecting terminals are micro-bumps (e.g., copper pillars with solder caps). The "connecting substrates" are flexible, single-layer polyimide bridges with traces that are fan-out bonded to the silicon interposers. The termination substrate is a silicon chip containing a feedback photodiode and a resistive network to close the loop, enabling real-time color and brightness calibration. The entire assembled light bar, measuring less than 10mm in length, is optically coupled to the edge of a diffractive waveguide.

Mermaid Diagram:

graph LR
    subgraph AR Light Engine
        A[Si Interposer R] <--> B(Flex Bridge);
        B <--> C[Si Interposer G];
        C <--> D(Flex Bridge);
        D <--> E[Si Interposer B];
        E <--> F{Terminator w/ Photodiode};
    end
    A -- contains --> uLED1((R));
    C -- contains --> uLED2((G));
    E -- contains --> uLED3((B));
    F -- provides feedback to --> A;
    F -- provides feedback to --> C;
    F -- provides feedback to --> E;
    subgraph Display
       AR_LE[AR Light Engine] --> WG[Diffractive Waveguide];
    end

2.2. Cryogenic-Environment Modular Illuminator

Enabling Description: This variation is designed for operation in cryogenic conditions (-150°C to -270°C) for use in scientific sensor arrays or deep-space instrumentation. The module substrates are made from a sapphire wafer for its thermal stability and low outgassing. The LEDs are quantum dot-based emitters specifically engineered for high efficiency at low temperatures. The connecting terminals are superconducting Niobium-Titanium (NbTi) pads. The connecting and termination substrates are also sapphire-based, and connections are made via ultrasonic wedge bonding with aluminum wires. The closed-loop circuit on the termination substrate is a precision-etched thin-film resistor with a near-zero temperature coefficient of resistance (TCR), ensuring stable electrical properties across the extreme temperature range.

Mermaid Diagram:

classDiagram
    class Module {
        +Substrate : Sapphire
        +LEDs : Quantum Dot
        +Terminals : NbTi Pads
    }
    class Connector {
        +Substrate : Sapphire
        +Bonding : Al Wire
    }
    class Terminator {
        +Substrate : Sapphire
        +Circuit : Zero-TCR Resistor
    }
    Module "1..*" -- "1" Connector
    Module "1" -- "1" Terminator
    Terminator : formsClosedLoop()


---

### **Axis 3: Cross-Domain Application**

#### **3.1. Aerospace: Smart Skin Conformable Lighting**

*   **Enabling Description:** The modular system is integrated into an aircraft's composite fuselage panels. The substrates are flexible polyimide printed circuit boards (PCBs) embedded between composite layers. The system is used for exterior formation lighting or interior mood lighting. Each module can be individually addressed. The termination substrate not only closes the electrical loop but also acts as a diagnostic hub, containing a microcontroller that performs a continuity and impedance check on the entire light bar upon startup, reporting status to the flight control system via a CAN bus interface. The modularity allows maintenance crews to replace only a failed section of the lighting strip without replacing the entire fuselage panel.
*   **Mermaid Diagram:**
    ```mermaid
    flowchart TD
        A[FMS: Flight Management System] -- CAN Bus --> B{Terminator/Gateway};
        B -- Power & Control --> C[Module 1];
        C --> D[Module 2];
        D --> E[...];
        E --> F[Module N];
        B -- senses loop --> F;
        subgraph Composite Fuselage Panel
            direction LR
            G[Outer Skin] -- embeds --> C;
            C -- embeds --> H[Inner Structure];
        end
    ```

#### **3.2. AgTech: Tunable-Spectrum Horticultural Lighting**

*   **Enabling Description:** The light source is an overhead grow light system. Module substrates are designed with specific LED types: one module type for deep red (660nm), another for royal blue (450nm), and a third for far-red (730nm). A grower can physically assemble a light bar with a custom ratio of these modules to create a light spectrum tailored for a specific plant's growth stage (e.g., vegetative vs. flowering). The connecting substrates simply pass power and control lines. The termination substrate contains DIP switches that allow the user to select a pre-programmed lighting cycle (e.g., 18/6 or 12/12 hours), with the closed-loop pattern enabling the terminator's onboard timer to control the entire bar.
*   **Mermaid Diagram:**
    ```mermaid
    erDiagram
        LIGHT_BAR ||--o{ MODULE : "comprises"
        MODULE {
            string type "Deep Red, Royal Blue, etc."
            int position
        }
        LIGHT_BAR ||--|{ TERMINATOR : "is terminated by"
        TERMINATOR {
            string timer_setting "18/6, 12/12"
            bool loop_closed
        }
        MODULE ||--|{ CONNECTOR : "connects"

3.3. Medical: Sterilizable, Disposable Endoscopic Illuminator

Enabling Description: The invention is embodied as a single-use, flexible light strip for disposable endoscopes. The entire assembly (modules, connectors, terminator) is fabricated on a single, thin strip of biocompatible polyether ether ketone (PEEK). The modules are populated with miniature white LEDs. The strip is scored or perforated between modules, allowing the surgeon to snap it to a desired length for a specific procedure. The termination "substrate" is the final section of the strip and contains a simple shorting bar pattern. When the strip is snapped to length, the final exposed terminals are manually shorted with a sterile, conductive cap which completes the circuit and activates the light. This allows a single product SKU to serve multiple procedural needs, reducing inventory.

Mermaid Diagram:

stateDiagram-v2
    [*] --> Uncut
    Uncut --> Snapped: Surgeon snaps to length
    Snapped --> Activated: Attach conductive cap
    state Snapped {
        note right of Snapped
            Final module's second
            terminal is exposed.
        end note
    }
    Activated --> [*]: Procedure complete / Disposed

Axis 4: Integration with Emerging Tech

4.1. AI-Optimized Display Backlight with IoT Monitoring

Enabling Description: Each module substrate (121) is equipped with a microcontroller, a temperature sensor, and a photodiode. The connecting substrates (140) carry a data bus (e.g., I2C). The termination substrate (145) acts as an IoT gateway with a low-power wireless chipset (e.g., LoRaWAN or NB-IoT). Each module reports its temperature, brightness, and power consumption to the gateway. An AI algorithm, running either on the display's main processor or in the cloud, analyzes this data. It builds a thermal and aging model for each LED, predicting failures and dynamically adjusting the drive current to individual modules to maintain uniform brightness across the entire display and maximize lifespan. The termination gateway sends alerts for predictive maintenance.

Mermaid Diagram:

sequenceDiagram
    participant AI as AI Engine
    participant Gateway as Terminator/IoT Gateway
    participant ModN as Module N
    loop Real-time Monitoring
        ModN->>Gateway: Send {Temp, Lumens, Power}
    end
    Gateway->>AI: Aggregate & Forward Data
    AI->>AI: Analyze aging/thermal model
    AI->>Gateway: Send New Drive Current for ModN
    Gateway->>ModN: Set new_current(value)

4.2. Blockchain-Verified Supply Chain for Critical Lighting

Enabling Description: This is applied to a system where component authenticity is critical, such as military or aviation lighting. Each module substrate and termination substrate is manufactured with a physically unclonable function (PUF) chip, which provides a unique, unforgeable hardware ID. At the time of manufacture, the PUF ID and component test data are registered as an asset on a private blockchain. When a light bar is assembled, the termination substrate, acting as a "reader," queries the PUF ID of each module in the chain. It validates each ID against the blockchain ledger to ensure all components are authentic and meet specifications. If an invalid module is detected, the light bar will not activate, preventing the use of counterfeit parts.

Mermaid Diagram:

flowchart LR
    subgraph Assembly
        A[Module 1 w/ PUF] --> B[Module 2 w/ PUF] --> C{Terminator w/ PUF & Reader};
    end
    subgraph Validation
        C -- Query PUF ID --> B;
        C -- Query PUF ID --> A;
        C -- Check IDs --> D[Blockchain Ledger];
        D -- Valid --> E[Activate Light Bar];
        D -- Invalid --> F[Error: Counterfeit Part];
    end


---

### **Axis 5: The "Inverse" or Failure Mode**

#### **5.1. Failsafe Termination Substrate with Redundant Paths**

*   **Enabling Description:** The system is designed for high-reliability applications like egress lighting. The LEDs on each module substrate are arranged in two parallel strings. The connecting substrates have dual sets of traces. The termination substrate contains a small monitoring circuit with a solid-state relay. It continuously monitors the current in both strings. If it detects an open circuit in the primary string (e.g., due to LED failure), it throws the relay, which reroutes power to the secondary, redundant string through a separate closed-loop pattern. This ensures the light bar remains at least partially lit even after a component failure.
*   **Mermaid Diagram:**
    ```mermaid
    graph TD
        subgraph Terminator
            A[Current Sense 1] --> C{Logic};
            B[Current Sense 2] --> C;
            C -- On Failure --> D[Relay];
            D -- Route Power --> E[Primary Loop];
            D -- Route Power --> F[Secondary Loop];
        end
        Terminator -- monitors --> G[Module Chain];

5.2. Graceful Degradation / Low-Power Mode Terminator

Enabling Description: The termination substrate is designed for battery-powered devices. It includes a voltage monitoring circuit. When the main system voltage drops below a predefined threshold, the monitoring circuit activates a secondary circuit path on the termination substrate. This secondary path is a high-resistance closed loop. When engaged, it significantly increases the total series resistance of the LED bar, dimming all LEDs to a very low level. This "safe mode" conserves power while still providing minimal illumination, for instance, as a "low battery" indicator or for emergency-level lighting.

Mermaid Diagram:

stateDiagram-v2
    Normal_Power: Full Brightness
    Low_Power: Dimmed
    [*] --> Normal_Power
    Normal_Power --> Low_Power: onBatteryLow()
    Low_Power --> Normal_Power: onCharge()
    Low_Power --> [*]: onShutdown()

    note right of Low_Power
        Terminator switches to high-R
        closed-loop path.
    end note


---

### **Combination Prior Art with Open-Source Standards**

*   **Scenario 1: DMX512 Integration for Architectural Lighting:** The light source apparatus is adapted for stage or architectural lighting. The connecting terminals on each module substrate include pins for a differential pair (Data+ and Data-). The connecting substrates are flexible PCBs that maintain the 120-ohm characteristic impedance required for the RS-485 physical layer used by DMX512. The termination connecting substrate (145) incorporates a standard 120-ohm resistor across the Data+ and Data- lines, providing the DMX bus termination required at the end of a DMX chain. Each module substrate contains a small DMX slave microcontroller (e.g., an ATtiny) that reads the DMX universe data and controls the local LEDs.

*   **Scenario 2: I2C/SMBus for Smart Display Backlights:** The connecting substrates carry SCL (clock) and SDA (data) lines in addition to power. Each LED module substrate acts as an I2C slave device, with its address set by solder jumpers or a pre-programmed EEPROM. A master controller can query each module for temperature, LED status (open/short), and individual brightness settings. The termination substrate contains the required I2C pull-up resistors for the bus. This allows for fine-grained, dynamic control of local dimming zones in an LCD backlight, compatible with the open SMBus standard for system management.

*   **Scenario 3: CAN Bus for Automotive Lighting Integration:** The modular light bar is designed for use as an interior ambient light or exterior signal light (e.g., a "CHMSL" - Center High Mount Stop Lamp) in a vehicle. The connecting substrates are designed as twisted pairs to carry the CAN_H and CAN_L signals. Each module substrate has a CAN transceiver. The final termination substrate includes a 120-ohm resistor to terminate the CAN bus, as per the ISO 11898 standard. This allows the light bar to connect directly to the vehicle's body control module, receiving commands and reporting diagnostic status without proprietary interfaces.