Patent 9900569

Derivative works

Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.

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Derivative works

Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.

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Defensive Disclosure for U.S. Patent 9,900,569

Publication Date: May 14, 2026
Subject: Derivative Works and Obvious Variations of Projection-Type Image Display Devices with Lamp-Wear Compensation

This document discloses a series of derivative works and improvements upon the core technological principles described in U.S. Patent 9,900,569. The intent of this disclosure is to place these concepts into the public domain, thereby establishing prior art against future patent applications for similar or incremental innovations. The following descriptions are intended to be enabling for a Person Having Ordinary Skill In The Art (PHOSITA).

Section 1: Derivative Works Based on Core Claims

The core claim of US 9,900,569 describes a system that compensates for discharge lamp degradation by using lamp voltage and accumulated usage time to control image correction. The following are derivative variations that expand upon this concept.

Axis 1: Material & Component Substitution

Derivative 1.1: Solid-State Electroluminescent Sensor for Voltage and Spectral Shift Detection

  • Enabling Description: The lamp voltage detection unit is replaced with a thin-film, solid-state electroluminescent (EL) sensor positioned proximate to the discharge lamp's arc tube. This EL sensor is fabricated from a doped zinc sulfide (ZnS) phosphor composite. The intensity of electroluminescence is directly proportional to the applied electric field, providing a non-contact method of inferring the inter-electrode voltage. Furthermore, the spectral characteristics of the EL sensor are designed to shift in response to changes in the spectral power distribution of the aging discharge lamp (e.g., color temperature shifts in a mercury-vapor lamp). The control unit receives both luminescence intensity and spectral shift data, using the latter as an additional input parameter for the image correction algorithm, allowing for more precise color balance correction (e.g., compensating for yellowing) in addition to brightness/contrast adjustments. The lighting period is managed by a simple, non-volatile ferroelectric RAM (FeRAM) counter, chosen for its high endurance and low power consumption.

  • Mermaid Diagram:

    graph TD
    A[Discharge Lamp] -- Electric Field & Spectral Output --> B(ZnS EL Sensor);
    B -- Luminescence Intensity --> C{Control Unit};
    B -- Spectral Shift Data --> C;
    D[FeRAM Counter] -- Accumulated Time --> C;
    C -- Correction Parameters --> E[Image Correction Processor];
    F[Input Image Signal] --> E;
    E -- Corrected Signal --> G[Image Display Element];

Derivative 1.2: Current Shunt Resistor with Thermoelectric Compensation

  • Enabling Description: Instead of directly measuring voltage, this variation infers the lamp's operational state by measuring current. A high-precision, low-inductance Manganin alloy current shunt resistor is placed in series with the lamp in the ballast power supply. A thermoelectric module (Peltier device) is thermally coupled to the shunt resistor, actively maintaining its temperature at a constant setpoint (e.g., 50°C ± 0.1°C) to eliminate temperature-induced resistance changes. The voltage drop across this thermally-stabilized shunt provides a highly accurate lamp current measurement. The control unit correlates this current measurement with the lamp usage period (stored in an EEPROM) and a pre-loaded lamp model (V-I curve degradation model) to estimate the effective lamp voltage and degradation state, which then dictates the image correction amount.

  • Mermaid Diagram:

    sequenceDiagram
    participant B as Ballast
    participant S as Shunt Resistor
    participant T as Peltier Module
    participant C as Control Unit
    participant I as Image Correction
    B->>S: Supplies Lamp Current
    activate S
    S->>C: Voltage Drop Signal
    T->>S: Active Cooling/Heating
    C->>T: Setpoint Control
    deactivate S
    C->>C: Correlate Current, Time, and V-I Model
    C->>I: Send Correction Parameters

Axis 2: Operational Parameter Expansion

Derivative 2.1: Cryogenic Temperature Projector for Superconducting Magnet Environments

  • Enabling Description: This disclosure describes the application of the invention in a projection system designed to operate within the cryostat of a superconducting magnet, for applications like functional MRI (fMRI) data visualization. The discharge lamp is a specialized Xenon arc lamp tolerant to low temperatures (e.g., 77 Kelvin). At these temperatures, the lamp's voltage-time degradation curve is significantly altered. The control unit stores a family of cryogenic-specific degradation curves. The "lamp voltage detection unit" is an optically isolated measurement circuit to prevent electromagnetic interference with the MRI's sensitive detectors. The "lighting period managing unit" logs not only time but also thermal cycles (warm-up/cool-down events), as these induce mechanical stress and are a primary failure factor in this environment. The image correction algorithm applies aggressive pre-compensation for both brightness decay and the significant blue-shift in color temperature that occurs when operating the lamp at cryogenic temperatures.

  • Mermaid Diagram:

    stateDiagram-v2
    [*] --> Cryo_Stable
    Cryo_Stable --> Thermal_Cycling: MRI Ramp Down
    Thermal_Cycling --> Cryo_Stable: MRI Ramp Up
    Cryo_Stable: Control Unit applies cryo-specific V-T curve for image correction.
    Thermal_Cycling: Lighting Period Manager logs cycle count. Correction is temporarily suspended.

Derivative 2.2: Ultra-High-Frequency AC Lamp Operation for Reduced Flicker

  • Enabling Description: To eliminate perceptible flicker in high-frame-rate scientific imaging applications (e.g., 1000 fps), the discharge lamp is driven by a ballast power supply operating at an ultra-high frequency (e.g., >200 kHz), as opposed to the conventional low-frequency square wave. At these frequencies, electrode wear mechanisms change, favoring sputtering over evaporative processes. The control unit uses a Fast Fourier Transform (FFT) analysis of the high-frequency voltage signal to detect harmonic distortions, which are correlated with specific electrode erosion patterns. This harmonic distortion signature, combined with the accumulated usage time, provides a more nuanced predictor of illuminance decay than the DC-equivalent voltage alone. The image correction unit can thus apply non-linear correction curves that better match the actual light output decay.

  • Mermaid Diagram:

    flowchart LR
    subgraph Ballast
        A(200kHz AC Power)
    end
    subgraph Lamp Assembly
        B{Lamp}
    end
    subgraph Control System
        C(Voltage Sampler) --> D(FFT Processor)
        D -- Harmonic Signature --> E{Control Unit}
        F(Time Counter) --> E
        E -- Correction Curve --> G(Image Corrector)
    end
    A --> B --> C
    G --> H(Display)

Axis 3: Cross-Domain Application

Derivative 3.1: AgTech - Grow-Light Spectral Compensation

  • Enabling Description: The system is adapted for horticultural lighting (grow lights) using high-pressure sodium (HPS) or metal-halide (MH) discharge lamps. As these lamps age, their spectral output shifts, which can negatively impact plant morphogenesis. A compact spectrometer, acting as the "voltage and spectral detection unit," continuously monitors the lamp's output spectrum. The "control unit" compares the real-time spectrum to an ideal photosynthetic active radiation (PAR) curve for a specific plant species. The "image correction processing unit" is replaced by a "spectral compensation unit," which controls an array of supplemental narrow-band LEDs (e.g., deep red at 660nm, far-red at 730nm, blue at 450nm). The control unit uses the deviation from the ideal PAR spectrum and the total usage hours to dynamically adjust the LED array's output, filling in spectral gaps created by the aging primary lamp, thus maintaining optimal growing conditions for the plant's entire life cycle.

  • Mermaid Diagram:

    graph TD
    A[HPS/MH Lamp] -- Light Output --> B(Spectrometer);
    A -- Voltage/Current --> C(Ballast);
    C -- Lamp Usage Time --> D{Control Unit};
    B -- Real-time Spectrum --> D;
    D -- Compares to Ideal PAR --> D;
    D -- LED Control Signals --> E[Supplemental LED Array];
    E -- Compensating Light --> F(Plants);
    A -- Primary Light --> F;

Derivative 3.2: Aerospace - Aircraft Landing Light Predictive Maintenance

  • Enabling Description: The invention is applied to high-intensity discharge (HID) Xenon landing and taxi lights on an aircraft. The "control unit" is integrated into the aircraft's health and usage monitoring system (HUMS). It continuously monitors the lamp voltage and logs the "lighting period" in terms of both hours and number of ignition cycles (a key stressor). Using a known degradation model for the specific lamp part number, the control unit calculates a "Remaining Useful Life" (RUL) estimate. Instead of correcting an image, the system's output controls a maintenance indicator on the flight deck or ground crew terminal. When the RUL drops below a predefined threshold (e.g., 50 hours), it triggers a maintenance alert, allowing for proactive replacement of the lamp during scheduled service, preventing mission delays or safety issues from in-flight failures.

  • Mermaid Diagram:

    sequenceDiagram
    participant L as Landing Light
    participant C as Control Unit (HUMS)
    participant M as Maintenance System
    loop Continuous Monitoring
        L->>C: Lamp Voltage
    end
    C->>C: Log Time & Ignition Cycles
    C->>C: Calculate RUL based on V, T, Cycles
    alt RUL < Threshold
        C->>M: Trigger Maintenance Alert
    end

Derivative 3.3: Medical Tech - Endoscopic Illuminator Quality Control

  • Enabling Description: In a medical endoscope, a powerful external Xenon or metal-halide lamp provides illumination via a fiber-optic light guide. The color rendering index (CRI) and color temperature of this light are critical for accurate tissue diagnosis. This system integrates a miniaturized color sensor (e.g., an AS7262 6-channel visible spectral sensor) at the illuminator's output port. This sensor provides data on the light's color properties. The control unit monitors this color data along with the lamp voltage and usage hours. The "image correction" is performed on the video signal coming from the endoscope's camera. The control unit generates a real-time color correction matrix (CCM) that is applied to the video feed, ensuring that the image displayed to the surgeon maintains a consistent, calibrated color balance (e.g., D65 white point) throughout the lamp's life, preventing misinterpretation of tissue color due to lamp aging.

  • Mermaid Diagram:

    flowchart TD
    A[Xenon Lamp] --> B(Fiber Optic Cable) --> C(Endoscope);
    A --> D(Voltage Sensor) --> E{Control Unit};
    F(Usage Timer) --> E;
    subgraph Illuminator
        G(Color Sensor) -- Color Data --> E;
    end
    H(Endoscope Camera) --> I(Video Processor);
    E -- Real-time CCM --> I;
    I -- Corrected Video --> J(Surgeon's Display);
    A --> G;

Axis 4: Integration with Emerging Tech

Derivative 4.1: AI-Driven Predictive Correction

  • Enabling Description: The control unit incorporates a trained neural network (e.g., a recurrent neural network - RNN) model. This model is trained on a large dataset of lamp voltage, current, usage time, and corresponding measured light output (luminance and spectral data) from hundreds of lamps tested to failure. The on-board control unit uses real-time lamp voltage and usage time as inputs to the RNN, which predicts the illuminance and spectral decay curve for the next 100 hours of operation with a high degree of accuracy. The image correction unit proactively applies a slowly changing correction factor based on this prediction, ensuring smoother and more imperceptible compensation to the user, rather than reacting to past changes. IoT connectivity allows the device to upload its operational data to a central server, contributing to the continuous retraining and improvement of the predictive model.

  • Mermaid Diagram:

    graph TD
    subgraph Projector
        A[Lamp] -- Voltage --> B(Controller);
        C[Timer] -- Usage --> B;
        B -- Input Vector --> D(On-board RNN);
        D -- Predicted Decay Curve --> E(Image Correction Unit);
    end
    subgraph Cloud
        F(Training Dataset) -- Trains --> G(Master AI Model);
        H(Data from Fleet) -- Updates --> F;
        G -- Deploys --> D;
    end
    B -- IoT Upload --> H;

Derivative 4.2: Blockchain for Lamp Authenticity and Supply Chain Verification

  • Enabling Description: Each lamp block is equipped with a secure microcontroller (e.g., an ATECC608A) that stores a unique private key. At the time of manufacture, the lamp's unique ID, initial performance data (voltage, luminance), and manufacturing date are recorded as a transaction on a private blockchain. When a new lamp is installed in the projector, the control unit initiates a cryptographic challenge-response with the lamp's secure microcontroller to verify its authenticity. It then queries the blockchain using the lamp's public ID to retrieve its certified initial performance data. This prevents the use of counterfeit lamps and provides the control unit with exact baseline data for its degradation calculations (as described in Example 2 of the patent), rather than relying on generic averages. The lighting period managing unit also writes major usage milestones (e.g., every 500 hours) to the blockchain as immutable records.

  • Mermaid Diagram:

    classDiagram
    class ProjectorController {
        +verifyLamp(lampID)
        +getInitialData(lampID)
        +updateUsage(lampID, hours)
    }
    class SecureLampModule {
        -privateKey
        +uniqueID
        +respondToChallenge()
    }
    class BlockchainLedger {
        +getTransaction(lampID)
        +addTransaction(data)
    }
    ProjectorController --> SecureLampModule : Communicates with
    ProjectorController --> BlockchainLedger : Reads/Writes

Axis 5: The "Inverse" or Failure Mode

Derivative 5.1: Graceful Degradation & Safe Failure Mode

  • Enabling Description: This variation is designed for applications where sudden loss of image is unacceptable (e.g., a control room or public display). The control unit monitors the rate of change of the lamp voltage (dV/dt). A rapidly increasing voltage is a precursor to catastrophic lamp failure (arc tube explosion). If dV/dt exceeds a critical threshold, the control unit initiates a "Safe Failure" mode. It immediately commands the ballast to reduce lamp power by 50%, which extends the remaining life but lowers brightness. Simultaneously, it instructs the image correction unit to apply maximum brightness and contrast gain to make the dimmer image as legible as possible. It also overlays a persistent but non-obstructive "Lamp Replacement Required" icon on the projected image and sends an SNMP trap or other network alert to a management system. This allows the system to continue operating in a limited-functionality state until maintenance can be performed, preventing an abrupt shutdown.

  • Mermaid Diagram:

    stateDiagram-v2
    Normal_Operation: Monitoring V and dV/dt
    [*] --> Normal_Operation
    Normal_Operation --> Safe_Failure : dV/dt > Threshold
    Safe_Failure --> [*] : Lamp Replaced
    
    state Normal_Operation {
        description "Applies standard image correction based on V and T"
    }
    state Safe_Failure {
        description "Reduce lamp power to 50%<br/>Apply max image gain<br/>Display maintenance icon<br/>Send network alert"
    }

Section 2: Combination Prior Art Scenarios

Combination 2.1: VESA DisplayHDR Standard Integration

  • Scenario: The projection system described in US 9,900,569 is combined with the open VESA DisplayHDR standard (e.g., DisplayHDR 1000).
  • Description: The projector is designed to be DisplayHDR compatible. The control unit's function is extended. In addition to compensating for lamp wear, it also uses the real-time lamp degradation data (derived from voltage and time) to dynamically adjust the tone-mapping algorithm for HDR content. As the lamp's peak luminance capability decreases with age, the control unit remaps the HDR Electro-Optical Transfer Function (EOTF), such as the Perceptual Quantizer (PQ), to the new, lower peak brightness. This ensures that HDR content is displayed with the maximum possible dynamic range available from the aging lamp, preventing severe clipping of highlights that would occur if a static tone-mapping curve were used. The correction becomes a dynamic HDR metadata recalculation based on the physical state of the illuminator. This combination is obvious to one skilled in the art seeking to maintain a certified level of display performance over the product's lifetime.

Combination 2.2: DMX512 Lighting Control Protocol Integration

  • Scenario: The system is integrated into a stage or architectural lighting projector that is controlled by the USITT DMX512-A open standard.
  • Description: The projector's control unit functions as a DMX512 node. One of the DMX channels is assigned to report the "Lamp Health" percentage, a value calculated by the control unit from the lamp voltage and usage time (e.g., 100% = new, 10% = nearing end-of-life). A separate DMX channel allows a remote lighting console to enable or disable the automatic image (or beam) correction feature. This allows a lighting director to choose between maintaining consistent output (auto-correction on) or manually compensating for dimming across multiple fixtures from the main console (auto-correction off). The ability to query lamp health and control the compensation feature over an industry-standard lighting network is an obvious integration for professional lighting applications.

Combination 2.3: MQTT Protocol for IoT Fleet Management

  • Scenario: The projector's control unit is equipped with an IoT module that communicates using the open MQTT (Message Queuing Telemetry Transport) protocol.
  • Description: The control unit acts as an MQTT client. It periodically publishes the lamp's status to a specific MQTT topic (e.g., projectors/serial_number/lamp/status). The published message, in a lightweight JSON format, contains the current lamp voltage, total usage hours, calculated illuminance decay percentage, and the currently applied correction level. An enterprise fleet management system subscribes to these topics, allowing an administrator to monitor the health of hundreds or thousands of projectors in real-time from a central dashboard. The system can automatically generate maintenance tickets when the illuminance decay reaches a certain threshold. This use of a standard, lightweight IoT protocol to expose the internal state calculated by the patent's method is an obvious extension for large-scale deployments.

Generated 5/14/2026, 6:48:30 AM