What Is Refresh Rate?
Refresh rate refers to how many times per second the LED driver circuit rewrites the pixel data across the entire display panel. It is expressed in Hertz (Hz). A display running at 1,920 Hz rewrites its pixel data 1,920 times every second; one running at 3,840 Hz does so twice as often.
This is distinct from the frame rate of the incoming video signal (typically 24, 30, or 60 frames per second). The driver circuit repeats - or "refreshes" - each incoming frame many times before the next frame arrives. Higher refresh rates mean each individual refresh cycle is shorter, which reduces the duration of any brief luminance drop between cycles and makes the image appear more stable and continuous to the human eye.
For most static or slow-moving content in a controlled environment, a refresh rate of 1,920 Hz is generally sufficient. For fast motion, bright ambient lighting, or any scenario involving camera capture, 3,840 Hz or higher is typically the accepted baseline.
What Is Scan Drive Mode?
Scan drive mode describes how the driver ICs on the LED module activate the pixel rows. Because it is not economical to provide a dedicated driver output for every single row simultaneously, the rows are divided into groups and activated in rapid sequence - a technique known as multiplexed scanning.
Common configurations include:
- 1/32 scan: the rows are divided into 32 groups, with 1/32 of the rows active at any moment.
- 1/16 scan, 1/8 scan, 1/4 scan: progressively fewer groups, meaning more rows are active at any given instant.
- Static drive (1/1): every row is driven simultaneously; no multiplexing.
A lower scan fraction (e.g., 1/32) means each row is "on" for a shorter duty cycle during each refresh pass. To maintain the same perceived brightness as a static-drive display, the driver must push higher instantaneous current through the LEDs during that brief window. This trade-off affects brightness consistency, thermal behaviour, and - at lower refresh rates - visible flicker.
Static-drive and low-scan-ratio configurations (1/4, 1/2) are generally preferred for high-brightness outdoor fixed installations where power efficiency and thermal stability matter most. Higher-scan-ratio configurations (1/16, 1/32) are more common in fine-pitch indoor panels where cabinet depth and power consumption must be minimised.
How These Two Parameters Interact
Refresh rate and scan mode do not operate independently. The actual luminance waveform seen by a camera sensor or a human eye is determined by their combined effect.
Consider a 1/16 scan display running at 1,920 Hz. Each of the 16 row groups is active for 1/16 of each refresh cycle. At 1,920 Hz, one full cycle lasts approximately 521 microseconds, so each row group is illuminated for roughly 32 microseconds per cycle. Increasing the refresh rate to 3,840 Hz halves that cycle duration to about 260 microseconds, meaning each row group is lit for approximately 16 microseconds - a shorter, more frequent pulse.
From the perspective of a rolling-shutter camera sensor, what matters is the ratio between the sensor's scan line exposure duration and the panel's luminance pulse timing. When these fall out of synchronisation, the sensor captures rows that are partially or fully dark, producing horizontal banding in the footage - commonly called "camera flicker" or "scan lines on camera."
Increasing the refresh rate reduces the probability of this misalignment because the luminance pulses become more frequent relative to the sensor's scan speed. This is why broadcast and live-event rental panels are typically specified at 3,840 Hz minimum, with premium products reaching 7,680 Hz or higher.
Practical Implications for Different Applications
Rental and live events: Camera compatibility is non-negotiable. Panels should carry a refresh rate of at least 3,840 Hz. Verify this figure under the actual operating colour depth and brightness setting, not just the peak specification, because some driver configurations reduce effective refresh rate when dimming or when higher bit-depth processing is enabled.
Fixed indoor installations (conference rooms, control centres): The primary concern is visual comfort under continuous viewing. A refresh rate of 3,840 Hz eliminates perceptible flicker for virtually all viewers. Scan mode choice here is mainly a power and thermal consideration.
Outdoor fixed installations: High ambient brightness and viewing distance mean scan mode and refresh rate have less impact on perceived image quality. The focus shifts to driver current stability and thermal management over long operating hours.
Retail and architectural LED: Environments with mixed lighting - fluorescent, LED downlights, and natural light - can create optical beat frequencies with low-refresh panels. 3,840 Hz is a reasonable minimum; some high-end retail deployments specify 7,680 Hz to eliminate any interaction with high-frequency dimming circuits in the venue lighting.
Key Points to Verify When Sourcing
- Confirm refresh rate at operating conditions, not peak lab conditions. Ask for the figure at 100% brightness and at the brightness level you intend to run.
- Clarify the scan configuration and understand its impact on driver current and heat dissipation for your installation environment.
- For broadcast use, request a camera test at the venue's camera frame rate and shutter speed before finalising the specification.
- Check driver IC documentation - the specified refresh rate is only achievable if the driver IC, the signal processing chain, and the controller all support it end-to-end.
Summary
Refresh rate determines how frequently the pixel data is rewritten; scan drive mode determines what fraction of the display is active at any instant. Together, they govern luminance stability, motion rendering, and camera compatibility. Neither parameter should be evaluated in isolation, and neither should be accepted at face value from a datasheet alone. Verifying both under realistic operating conditions is the most reliable way to ensure the display performs as expected in its intended environment.