Device Functionality

So what does the manufacturer offer in its new device? Today it doesn’t suffice to issue “just an optical drive”; the hardware simply must have an impressive trail of “exclusive features”. It’s not even important that almost all of this exclusiveness can be easily realized in competing devices –thinking out a loud marketing name and keeping secretive about the operational principle of the feature make the trick! Fortunately, the BenQ DW1620 is almost free from such blame. There’re some most remarkable things in this drive, truly deserving our attention.

Over-Speed Burning Technology and Seamless Link can be skipped over without much dwelling upon as they are too obvious (if you are completely not in the know, the former technology allows writing discs at a higher speed than they are rated for, and the latter is a protection system against buffer underrun errors).

Let’s better go over to really interesting functions like the following.

• High-Speed Signal Algorithm:
  

  

  The manufacturer doesn’t let us into the technological details of this function, but still offers some general info. When a disc is being written at a high speed, the signal may become lost for a short while and that would lead to a sudden degeneration of the quality of the medium. HSAA technology is controlling the EFM signal in such as way as to avoid this problem and thus to increase the overall quality of the resulting disc.

• Walking OPC and BLER OPC:
  

  

  The classical strategy of an optical drive is to calibrate the power of the laser (Optimum Power Control – OPC) at the beginning of the disc prior to starting the burn session. Today, however, almost all modern devices support the so-called Running OPC when the power of the laser is being adjusted throughout the entire burn session. Thus, by Walking OPC the manufacturer means an incessant control over the quality of the disc being burned and appropriate correction of the laser power. As for the BLER OPC, this technology has been already implemented by Samsung in its TS-H552B drive. It denotes a repetition of the OPC procedure on the outermost tracks of the disc where the burn quality usually suffers the most due to the high rotational speed and vibration. The BenQ DW1620 makes use of a hybrid or combination of these two technologies.

• Tilt Control:
  

  

  This function is also becoming popular in modern optical drives. It ensures that the laser beam falls on the disc surface at the same angle of 90 degrees irrespective of the warping of the medium itself, of vibration and other factors. The specifics of the Tilt Control technology are not revealed, but there are two possible solutions: adjusting the lens position (like in Samsung’s drives) or using an “optical wedge”, an additional plate with liquid-crystal coating (like in Pioneer’s drives), or a combination of both when the position of the lens as well as the optical head can be adjusted (in the last Plextor, the PX-716A model). It’s hard to say which method is employed here. BenQ claims to maintain the angle of the laser constant, while the competitors also ensure a high accuracy of focusing the laser on the track.

• Sliding Cone Mechanism:
  

  

  The use of a cone-shaped spindle head with a special spring mechanism allows maintaining the balance of the medium at high speeds, which positively affects the readability of the data as well as the access time. The spring mechanism improves the clamping force over on the disc, leading to a more stable reading of the data.