Laser Printers Guide

Oki B840dn review

Oki B840dn A3 Mono LED Printer - The Speed of Light

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Overall rating 9/10
Very fast print speed
Good print quality
Good expandability options
Driver installation process can be better


The LED Proposition

There’s always been some level of confusion among consumers regarding the difference between a printer using laser technology and one that uses LED technology. In truth, both use the same underlying print technology, which is using static electricity to apply toner to paper. What differs however, is how light is being transmitted to form the image on the drum. Simply put, with a laser printer, an optical scanning system is used and laser scans from one end of a line to the other; and it does this line by line.

On the other hand, an LED printer has a print head that’s made up of an array of light emitting diodes. So instead of scanning from one end to the other, the LEDs in the row flash at once (but selectively) to create the latent image. And some of you might have guessed it: a 600dpi LED printer means that the print head has 600 LEDs per inch. Multiply that by the length of the array and you get several thousands of tiny LEDs.

Proponents of the LED camp will tell you that this results in printers that are more compact, quieter (due to fewer moving parts) and more affordable, compared to their laser counterparts. In the past, the biggest complaint about LED printers was their low resolution (usually not more than 600dpi). But with advancement in LED technology, that’s less of an issue these days. In the market right now, there are several printer bigwigs that have LED printers in their stable of products, such as Brother, Fuji Xerox (with its SLED variant), Lexmark and Oki.

The Oki B840dn that we’ve here is an A3 monochrome LED printer targeted at businesses and small to medium workgroups (up to 30 users). It prints in A4 at a speed of 40ppm (pages per minute) and in A3 at 22ppm. In order to better cope with rendering load (especially in a networked environment with many users), it’s equipped with a 533MHz processor and 128MB of RAM. Print resolution tops out at 1200 x 1200dpi. It can be hooked using a variety of interfaces: USB, Ethernet (10/100 Base-TX) or parallel. It also does emulation for common printer languages and SIDM (serial impact dot matrix) such as PCL 5e, PCLXL, PostScript3, Epson FX and IBM ProPrinter. To get up to speed with its full specs, check the product specs (also seen in the shortcut next to the article thumbnail).


Depending on where you’re located, you may find the Oki B840 in as many as three configurations. The B840n comes with network connectivity but doesn’t support duplex printing. The B840dtn comes with network and duplex features, as well as an additional 530-sheet paper tray (on top of the standard 530-sheet one). The B840dn (which is what Oki Data Singapore carries) comes with both network and duplex support. To speed up processing of large files, the RAM can be upgraded to a maximum of 640MB. You can also order a 16GB SD card that's used for storage of overlays, macros and downloadable fonts, and for automatic collation of multiple copies of multi-page documents. We’ve prepared a price list of the accessories and consumables below.

Accessories & Consumables
Type Price
256MB RAM S$319
512MB RAM S$532
16GB SDHC (upon special request) S$519
2nd/3rd Paper Tray (530 sheets each) S$499 (each)
6,000-page Toner S$116
15,000-page Toner S$223
30,000-page Drum S$199