IR Sensing & Remote Control

Infrared LEDs at 850nm and 940nm are the emitters in a wide range of sensing and control applications. At 940nm, silicon photodetectors achieve near-peak response while ambient visible light interference is minimized — this wavelength is the standard for consumer and commercial IR remote control and short-range proximity sensing. At 850nm, output power is higher for a given drive current, making it preferred for longer-range or through-air sensing where detector sensitivity is less of a constraint.

Unlike visible LEDs, IR emitters are specified primarily on radiant intensity (mW/sr) and total radiant flux (mW) rather than luminous intensity (mcd). Drive currents are typically much higher than visible indicators — 50–100mA continuous, with pulse drive up to 500mA for distance sensing applications at low duty cycle. SMD IR packages in 0805 and 0603 footprints provide compact integration for PCB-level sensing circuits.

The IR LED market for sensing and control in North America is estimated at $200M–350M annually, spanning a diverse range of applications:

• Office and commercial equipment — printers, copiers, and multifunction devices use IR sensors extensively for paper path detection, document presence, and tray level monitoring. Each unit may contain 10–20 IR emitter/detector pairs
• Building automation — occupancy sensors, HVAC damper position sensors, and window/door state detectors use IR proximity sensing in commercial and institutional buildings
• Industrial automation — object detection, part counting, and position sensing on automated assembly lines and conveyor systems represent a large and growing segment
• Consumer and commercial AV equipment — IR blasters, repeaters, and custom remote control designs for AV integration remain an active application segment

• Laser printer paper path: 6–8 IR emitter/detector pairs detect paper presence, skew, and jam conditions along the paper path — each emitter is a 940nm LED mounted 15–25mm from a paired detector
• Ceiling occupancy sensor: A PIR occupancy sensor uses an 850nm IR LED for active distance confirmation, supplementing passive PIR detection with a short-range proximity check to reduce false negatives
• IR remote control blaster: A whole-home AV control system uses a 940nm emitter to transmit learned remote codes to equipment in enclosed AV cabinets
• Industrial conveyor part counter: A through-beam sensor with a 940nm emitter and separate detector counts parts as they interrupt the beam at production rates up to 2,000 parts per minute

Radiant intensity consistency is the key supply-chain advantage for IR sensing applications. In a paper path detection system with 8 sensor pairs, variation in emitter output between batches changes the switching threshold of the detector circuit — potentially requiring firmware recalibration or hardware adjustment when replacement components arrive from a different factory batch. This creates a hidden support cost that single-factory sourcing eliminates.

CMH's consistent production process for IR emitters ensures radiant intensity and emission angle specifications are reliably maintained across orders. For OEMs producing high-volume equipment over multi-year runs, this eliminates a significant source of production variability and field return risk.