Why you should buy an optical mouse

If you have been using the Mac all your life, you probably think the mouse is more important than the keyboard. On the PC side, the mouse, which was one of the major inventions of Doug Englebart, was already there in the mid 1980s, even before Microsoft came up with its Windows graphical user interface (GUI). However, it was after Windows 3.0 gained widespread acceptance that the mouse began to be sold as part of the PC -- along with its keyboard.

You must also have become familiar with the most common problem of the old mice: The dirt picked up by the mouse ball from the desk surface is transferred to the roller bars up in the ball's cavity. Sometimes the roller bars are wrapped in a thick layer of varnish and dust particles that they become clogged. You move your mouse angrily across the desk, but the cursor will remain stationary on your screen.

So, once a month you have to turn the mouse over, open the cover of the cavity and try to clean the two roller bars and sometimes a stabilizing wheel with a cotton bud and a lot of alcohol. If it has already gotten so dirty, the only thing you can do is to throw it away and buy a new one.

Another common problem with the mechanical mice is the four tiny plastic pads that enable the mouse to glide smoothly over the surface of the desk or a mouse pad. These plastic pads are usually glued to the underside of the mice, one on each corner.

The problem is that they get removed very easily. If you lose them, the "ground clearance" of the mouse base will be reduced as it sits lower to the surface. This will decrease the ball's traction, and you are left wondering why the screen pointer does not move as fast and as far as you move the mouse.

A mechanical mouse does not cost much, it costs around Rp 70,000 or so. However, if it stops working when you have no intention of going to a computer store to buy a new one, it can be a nuisance.

The newer technology, which is becoming increasingly popular nowadays, does away with the ball and the roller bars. Instead, the new mice use an optical sensor -- Logitech's latest mice use dual sensors -- to track their movement as we push them around. The benefit is clearly longer lasting mice, as there are no more moving parts that collect dirt and dust.

On the market today there are a number of optical mice offered by Apple, Kensington, Logitech and Microsoft. Here in Indonesia Logitech optical mice (corded and cordless) are the only ones that are widely available. Incidentally, for those who want to be able to use their notebook with a mouse on the cramped airplane food tray, the Raymond Sarrio Company (www.sarrio.com) has the Super Mini Optical Mouse, a very tiny mouse that can be used on a notebook's palmrest.

How does an optical mouse actually work? A white paper from Logitech explains that each optical mouse has three important components: A lens, a Digital Signal Processing (DSP), and an interface to the computer.

A Light Emitting Diode (LED) illuminates the surface underneath the mouse. The lens, which is actually a tiny camera, scans the image of the surface underneath it -- whether a mouse pad or a desk surface -- at a rate of 2000 times per second. Logitech's optical mice, which use the technology that it has developed with Agilent Technologies, scans the surface at a high resolution of 800 Dots Per Inch (DPI). The sensors then send the signals to the DSP. The chip then calculates, based on the scanned images, the speed and the direction of the mouse's movement based on the X-Y coordinates. The data will then be sent to the computer's operating system via the serial interface, and then the OS will then move the mouse on the screen accordingly.

What to check when choosing a new optical mouse? As with the mechanical mouse, you should choose one that feels the most comfortable to hold. It should not be too large or too small for your palm. Then decide whether you want a four-button or a five- button mouse or you are happy with just a three-button mouse. The more buttons you have, the less your hand will have to fly back and forth between the keyboard and the mouse.

Whatever you decide, just buy an optical mouse -- preferably even a cordless optical mouse. And when you already have an optical mouse, the only thing you need to avoid is using a mirror as your mouse pad.

-- Zatni Arbi