Because the paper must be physically turned over inside the feeder, this technology is often referred to as a "reversing" document feeder (RADF). What is an SPDF? (Single Pass Document Feeder)
The paper passes over the scanner glass a second time to read the back side (Side B). The paper is ejected into the output tray.
You frequently scan double-sided documents and need to maximize productivity. difference between spdf and dadf best
But if you are looking for a technical comparison to determine which is "best" for your specific application, you need to understand their function, efficiency, and limitations. This article breaks down the to help you decide which technology reigns supreme in its respective field.
The is generally recognized as the best technology for modern, high-speed, dual-sided scanning, often marketed as a Dual Scan document feeder or a high-end duplex feeder. While the term DADF implies duplexing, it is crucial to ensure it is a "single-pass" DADF rather than a reversing (ARDF) one to get the maximum benefit. Because the paper must be physically turned over
You need a duplex copier but want to keep hardware procurement costs low.
The paper goes in the top, comes out the back or front. Physics dictates that this is always less prone to jamming. The paper is ejected into the output tray
| Feature | DADF | SPDF | |---|---|---| | Full Name | Dual Auto Document Feeder | Single Pass Duplex Feeder | | How It Scans Two Sides | Two passes (front → flip → back) | One pass (both sides at once) | | Typical Scanning Speed | ~55 images per minute (ipm) | Up to 80–130 ipm | | Document Capacity | ~110 sheets | Up to 130 sheets or more | | Scanning Arrays | One scanning unit | Two scanning units (front + back) | | Mechanical Complexity | Lower – fewer moving parts | Higher – more sophisticated | | Scanner Lifespan Concern | Lower wear on feed roller | Paper makes only one pass | | Ideal User | Small to mid‑size office, low to medium volume | High‑volume office, fast scanning required | | Cost | Lower purchase price | Higher purchase price |
One sensor scans side A, reverses the paper, then scans side B. Slower, more moving parts, higher risk of jams. SPDF vs. DADF: Which is Best?
rely on complex internal gates, reversing rollers, and precise timing gears to flip the paper. Over time, these moving parts wear down, leading to a higher frequency of paper jams and maintenance calls.
While SPDF holds the performance crown, DADF systems remain incredibly popular for several compelling reasons. Lower Upfront Capital Cost