Bi-color/Multicolor LED

Bi-Color & Multi-Color LEDs

Tech-LED’s Bi-Color and Multi-Color LED category includes LEDs that emit two or more colors from a single package. These devices integrate multiple LED chips of different wavelengths, allowing one component to produce various colors or a combined output (for example, blending colors for an intermediate hue or broad spectrum). Our bi-color LEDs typically have two chips (often with separate leads or a common cathode/anode configuration), while multi-color LEDs may have three or more chips (such as RGB LEDs or even 4-in-1 and 5-in-1 packages). We engineer these LEDs so that the different dies are closely co-located, ensuring that light originates from virtually the same point for good color mixing. The multi-color lineup spans from simple two-color indicator LEDs to advanced multi-wavelength emitters for specialized uses (like combined IR+Visible for biometric sensing). Each device in this family exemplifies versatility – one LED, multiple functions.

Features of Tech-LED Bi/Multi-Color LEDs

• Diverse Color Combinations: We offer standard combinations such as Red/Green bi-color LEDs (commonly used in indicators where one device shows red or green status) and Red/Blue, Blue/Green etc. On the multi-color side, our RGB LEDs pack red, green, and blue chips to produce any color via mixing. We also have unique combos like RGB+IR (for devices that need both illumination and IR night-vision capabilities) or UV + visible combinations. A specialty example is a dual-IR LED with 850 nm and 940 nm chips together, used in eye tracking or IR illumination systems to allow switching between wavelengths for stealth or range considerations. Essentially, if you need two specific wavelengths in one package, there’s a good chance we either have it or can customize it – custom multi-wavelength LED solutions are a forte of ours.
• Single Package, Multiple Chips: By integrating chips in one package, these LEDs save board space and ensure the colors emanate from the same location. This is crucial for color mixing and uniform illumination. For instance, our 5 mm through-hole bi-color LEDs have two chips oriented so their light overlaps within the epoxy lens – so when both are on, you see a combined color, not two separate points. In SMD formats, we often use a 4-pad design (for two chips) or 6-pad (for three chips like RGB), or a common cathode/anode arrangement to reduce pin count. The chips can be driven independently to produce static colors or dynamically mixed for millions of colors (in the case of RGB under PWM control). Multi-color packages are carefully designed so that each chip has a balanced luminous intensity; we match chips that complement each other in brightness so that one color doesn’t overpower the others unless intended.
• Wide Wavelength Range (365 nm to IR): What sets Tech-LED’s multi-color offerings apart is that we include non-visible wavelengths too. We have bi-color LEDs that mix visible and infrared, or even UV and visible, in one package. For example, a vital sign monitoring LED might combine a 660 nm red and a 940 nm IR LED in one device – which is exactly what’s used in pulse oximetry probes to measure oxygen saturation (red and IR transmitted through tissue). We provide such dual-wavelength LEDs in convenient packages for medical OEMs. Likewise, an agriculture sensor LED might have a blue chip and an NIR chip to do dual-band reflectance (blue for chlorophyll, NIR for biomass). We cover from UVA to SWIR in these combos, allowing very creative sensor and illumination design in one compact unit.
• Applications Built-In (Indicator & Sensor Friendly): Many of our bi-color LEDs are tailored for common uses. For instance, we have dual-color LEDs for status indicators where the LED has opposite polarities for each color (apply voltage one way for, say, green, reverse for red). These are used in equipment panels to indicate different states (standby vs active, etc.) without needing two separate LEDs. For multi-color illumination, our packages ensure good color mixing, often by using diffused lenses or close chip spacing. A good example is our RGB SMT LED which has a diffused epoxy that blends the output into a uniform color at a short distance – perfect for signage or displays. On the other hand, for spectroscopy uses, we keep the emissions separate but in one package for alignment – e.g., a UV + blue + IR triple-LED for a portable spectrometer, where each can fire sequentially onto a sample but they emanate from the same spot for consistent geometry.
• Custom Multi-LED Modules: Beyond single-package multi-color LEDs, this category also covers small modules like LED arrays with multiple colors (for example, a small PCB with an array of alternating red and IR LEDs for an SpO₂ sensor). These are essentially pre-configured multi-color solutions. Tech-LED is open to customizing such modules if you need multiple different LEDs arranged in a certain way for uniform coverage or certain ratios. But even at the single component level, our multi-color LEDs often have carefully chosen chip size ratios to get desired color balance (for example, using a larger die for a color that is typically less efficient so that its brightness matches the others). We also pay attention to forward voltage and drive current matching so that driving circuits can be simpler when transitioning between colors.

Applications of Bi-Color and Multi-Color LEDs

Status and Indicator Lighting: One of the most common uses of bi-color LEDs is status indication. Think of a single LED on a device that glows green during normal operation and red for an error – that’s a bi-color LED at work. Tech-LED supplies these to numerous equipment manufacturers. Our red/green and red/blue through-hole LEDs are found on everything from power supplies to telecom hardware, indicating statuses clearly with one indicator window. The benefit is a simpler, cleaner interface (one LED, two colors) and sometimes reduced drilling/board holes on a PCB. Similarly, in automotive dashboards, bi-color or even tri-color LEDs create multi-function telltales (like a single LED icon that can change color depending on severity of a condition).

Multi-Color illumination and displays: RGB LEDs, in particular, enable full-color displays and lighting that can change color. Our high-brightness RGB SMD LEDs are used in LED signage, message boards, and decorative lighting where millions of colors are needed. By PWM-controlling each die, customers can generate any hue or perform color-changing effects. We also service the stage lighting and entertainment industry with multi-color LEDs (and modules like small RGBW clusters) that serve as building blocks for LED stage lights or pixel mapping LED curtains. Having tightly grouped multi-chips ensures the light is mixed at the source, producing saturated colors or tunable white light for lighting designers.

Medical sensing (Pulse Oximetry & Vital Signs): As mentioned, a critical application for dual-color LEDs is in pulse oximeters and heart rate sensors. These devices typically use a red (~660 nm) and an IR (~940 nm) LED that shine through a fingertip or earlobe, and a photodiode reads the transmitted light to determine oxygen saturation and pulse. Tech-LED’s bi-color red/IR LEDs are used in medical OEM finger clips and even in wearables for this purpose. By integrating the two wavelengths in one package, we ensure they are co-linear – which improves measurement accuracy and simplifies the opto-mechanical design. We also produce green/IR combos for newer wearable heart-rate monitors (some wearables use green for daytime use and IR for night or low-power mode). The eye-tracking and facial recognition systems can also benefit: some designs use a visible LED (for user-facing feedback) and an IR LED (for camera tracking) combined, for example in an AR/VR headset – a single component can provide a visible indicator light as well as an IR illuminator for the eye-tracking camera.

Remote controls and IR communication: A less obvious multi-“color” application is pairing IR LEDs of different wavelengths for improved IR communication. For instance, an IR remote or beacon might use a dual IR LED (850 nm + 940 nm) to take advantage of the higher power of 850 nm and the complete invisibility of 940 nm. Together, they can create a broader IR spectrum that is easier for a receiver to pick up (some sensors respond better at 850, others at 940). Tech-LED has provided custom dual-IR emitters for remote controls that need extended range and reliability under various lighting conditions.

Horticulture and Agriculture: Multicolor LEDs (particularly red + blue, and red + far-red) are significant in smart farming. Plants respond strongly to certain wavelengths (blue ~450 nm for vegetative growth, red ~660 nm for flowering, far-red ~730 nm for phytochrome responses). Our dual-color plant growth LEDs combine, for example, 660 nm and 730 nm in one package. This allows very compact grow light designs where each LED outputs a mix optimized for plant development. Similarly, some of our customers use UV + white dual LEDs to give a mix of UV (to enhance plant color or pest resistance) and white light (for human visibility in the grow area) in greenhouse lighting.

Indicators with configurable color: Some devices let users or systems change the indicator color (for example, an LED ring on a smart speaker that can be any color). These often use our tri-color (RGB) LEDs underneath a light guide to create a smooth, uniformly colored ring. By combining three colors in one LED, it’s easier to calibrate and get uniform mixing than separate single-color LEDs spread out. We have high-consistency RGB LEDs for such uses, ensuring that from unit to unit the color coordinates match when driven equally.

In essence, wherever there’s a need for multiple colors from one point, Tech-LED’s bi-color and multi-color LEDs are the solution. They simplify design (fewer LEDs to place), save space, and often improve the functionality (color alignment, mixing, and matching) compared to discrete single-color LEDs. From user interface lights to complex biomedical sensors, these multi-color LEDs provide flexibility and functionality that single-color LEDs cannot – all in a neat, efficient package. Our expertise in combining chips means customers can request unusual pairings (say, a custom 4-wavelength LED that puts 470 nm, 560 nm, 660 nm, and 940 nm together for a specialized analyzer) and we can deliver a reliable component that meets those needs. This commitment to customization and performance is why leading product developers turn to Tech-LED for multi-color LED solutions.