800nm Bandpass Filter

Context: This patent describes a sensor system used for 3D gesture recognition (often found in gaming consoles, automotive controls, or consumer electronics).

Usage of Filter: The bandpass filter is designed to have a passband starting at 800 nm (specifically covering the 800–1100 nm range) and is placed over an optical sensor. Its function is to transmit the Near-Infrared (NIR) light emitted by the system's own light source while blocking visible ambient light.

Function: It acts as a "noise cleaner" for the sensor, ensuring that only the specific wavelength of light used for tracking (800nm+) reaches the detector.

Result: This achieves a high Signal-to-Noise Ratio (SNR), allowing the device to accurately detect hand movements and gestures even in brightly lit rooms where visible light would otherwise flood the sensor.

Context: This patent relates to a medical imaging system used during surgery to visualize blood flow or tumors using fluorescent dyes (like Indocyanine Green, or ICG).

Usage of Filter: An 800 nm bandpass filter (or a filter isolating the ~800 nm emission band) is placed in front of the fluorescence camera sensor.

Function: The filter blocks the excitation light (which might be around 760–785 nm) and allows only the fluorescence emission (which peaks near 800–830 nm) to pass through to the camera.

Result: This results in a high-contrast image where the cancerous tissue or blood vessels "glow" brightly against a dark background, enabling surgeons to see critical structures that are invisible to the naked eye.

Context: This patent covers advanced flow cytometry systems used to analyze cells in a fluid stream for biological research or medical diagnosis.

Usage of Filter: Bandpass filters in the 800 nm region are used in the detection arm of the optical system.

Function: They isolate specific fluorescence signals emitted by cells labeled with NIR-emitting fluorophores (dyes that emit light at 800nm) from other scattering light or overlapping fluorescence channels.

Result: This achieves enhanced image resolution and precise sorting of cells based on their biological properties, allowing researchers to distinguish between different cell types with high accuracy.